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Sample records for accelerated fractionation radiotherapy

  1. Modelling accelerated fractionation in radiotherapy

    This study was undertaken to investigate optimum treatment schedules for highly proliferative tumours. The linear quadratic model is used to predict the most effective fractionation regimes. It should be pointed out that greater early effects are associated with improved tumour control, as such these data should be treated as a useful guideline and should never be used out of context with clinical experience. The linear quadratic model with proliferation has been used to investigate the effect on cell survival and associated tumour control probability (TCP)

  2. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    Rasmussen, Rune, E-mail: rune333@gmail.com [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Claesson, Magnus [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Stangerup, Sven-Eric [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Roed, Henrik [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); Christensen, Ib Jarle [Finsen Laboratory, Rigshospitalet, Copenhagen (Denmark); Caye-Thomasen, Per [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Juhler, Marianne [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark)

    2012-08-01

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a 'wait-and-scan' group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  3. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a “wait-and-scan” group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  4. Fractionated stereotactic radiotherapy of vestibular schwannomas accelerates hearing loss

    Rasmussen, Rune; Claesson, Magnus; Stangerup, Sven-Eric;

    2012-01-01

    To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hear......To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea...

  5. Comparison of remote results of conventional fractionation radiotherapy and late course accelerated hyperfractionation radiotherapy for nasopharyngeal carcinoma

    Objective: To compare the long-term effects of conventional fractionation (CF) radio-therapy and late course accelerated hyperfractionation (LCAHF) radiotherapy of nasopharyngeal carcinoma (NPC), and to arrive at a appropriate NPC radiotherapy protocol. Methods: According to the criteria, 496 patients with NPC were allotted to our retrospective analysis, including 269 in the CF group and 227 in the LCAHF group. Two large lateral opposing fields were first used to treat the nasopharynx and the upper neck at a fraction of 2 Gy daily, 5 days per week. After 36-40 Gy, two small lateral opposing fields were used to boost the primary tumor while the spinal cord shielded. In the CF group, the accumulated total dose of naso-pharynx was 68-76 Gy at 2 Gy daily. In the LCAHF group, the radiation fraction of primary tumor was 1.5 Gy twice daily, with a minimum of six-hour interval in the late course. The accumulated total dose was 69-72 Gy. Survival was assessed by Kaplan-Meier method and Logrank analysis. Results: The 5-year primary site control, tumor-free survival and overall survival rates was 65.4% ,61.5% and 68.1% in the LCAHF group and 52.8%, 49.4% and 57.5% in the CF group. The difference between the two groups were significant (P=0.006, 0.006 and 0.031). Further analysis showed that LCAHF improved the primary site control, tumor-free survival and overall survival rates of T2-T3 NPC (P0.05). Conclusions: When compared with conventional fractionation radiotherapy, late course accelerated hyperfractionation radiotherapy, being tolerable, definitely can improve the local control, tumor-free survival and overall survival in patients with nasopharyngeal carcinoma. But the recurrence rates of cervical lymph nodes and distant metastasis were similar in between these two groups. (authors)

  6. Visual Outcome in Meningiomas Around Anterior Visual Pathways Treated With Linear Accelerator Fractionated Stereotactic Radiotherapy

    Purpose: Meningiomas threatening the anterior visual pathways (AVPs) and not amenable for surgery are currently treated with multisession stereotactic radiotherapy. Stereotactic radiotherapy is available with a number of devices. The most ubiquitous include the gamma knife, CyberKnife, tomotherapy, and isocentric linear accelerator systems. The purpose of our study was to describe a case series of AVP meningiomas treated with linear accelerator fractionated stereotactic radiotherapy (FSRT) using the multiple, noncoplanar, dynamic conformal rotation paradigm and to compare the success and complication rates with those reported for other techniques. Patients and Methods: We included all patients with AVP meningiomas followed up at our neuro-ophthalmology unit for a minimum of 12 months after FSRT. We compared the details of the neuro-ophthalmologic examinations and tumor size before and after FSRT and at the end of follow-up. Results: Of 87 patients with AVP meningiomas, 17 had been referred for FSRT. Of the 17 patients, 16 completed >12 months of follow-up (mean 39). Of the 16 patients, 11 had undergone surgery before FSRT and 5 had undergone FSRT as first-line management. Tumor control was achieved in 14 of the 16 patients, with three meningiomas shrinking in size after RT. Two meningiomas progressed, one in an area that was outside the radiation field. The visual function had improved in 6 or stabilized in 8 of the 16 patients (88%) and worsened in 2 (12%). Conclusions: Linear accelerator fractionated RT using the multiple noncoplanar dynamic rotation conformal paradigm can be offered to patients with meningiomas that threaten the anterior visual pathways as an adjunct to surgery or as first-line treatment, with results comparable to those reported for other stereotactic RT techniques.

  7. Visual Outcome in Meningiomas Around Anterior Visual Pathways Treated With Linear Accelerator Fractionated Stereotactic Radiotherapy

    Stiebel-Kalish, Hadas, E-mail: kalishhadas@gmail.com [Neuro-Ophthalmology Unit, Rabin Medical Center, Petah Tikva (Israel); Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Reich, Ehud [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Department of Ophthalmology, Rabin Medical Center, Petah Tikva (Israel); Gal, Lior [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Rappaport, Zvi Harry [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Department of Neurosurgery, Rabin Medical Center, Petah Tikva (Israel); Nissim, Ouzi [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Stereotactic Radiosurgery Unit, Sheba Medical Center, Ramat Gan (Israel); Department of Neurosurgery, Sheba Medical Center, Ramat Gan (Israel); Pfeffer, Raphael [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Stereotactic Radiosurgery Unit, Sheba Medical Center, Ramat Gan (Israel); Spiegelmann, Roberto [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Stereotactic Radiosurgery Unit, Sheba Medical Center, Ramat Gan (Israel); Department of Neurosurgery, Sheba Medical Center, Ramat Gan (Israel)

    2012-02-01

    Purpose: Meningiomas threatening the anterior visual pathways (AVPs) and not amenable for surgery are currently treated with multisession stereotactic radiotherapy. Stereotactic radiotherapy is available with a number of devices. The most ubiquitous include the gamma knife, CyberKnife, tomotherapy, and isocentric linear accelerator systems. The purpose of our study was to describe a case series of AVP meningiomas treated with linear accelerator fractionated stereotactic radiotherapy (FSRT) using the multiple, noncoplanar, dynamic conformal rotation paradigm and to compare the success and complication rates with those reported for other techniques. Patients and Methods: We included all patients with AVP meningiomas followed up at our neuro-ophthalmology unit for a minimum of 12 months after FSRT. We compared the details of the neuro-ophthalmologic examinations and tumor size before and after FSRT and at the end of follow-up. Results: Of 87 patients with AVP meningiomas, 17 had been referred for FSRT. Of the 17 patients, 16 completed >12 months of follow-up (mean 39). Of the 16 patients, 11 had undergone surgery before FSRT and 5 had undergone FSRT as first-line management. Tumor control was achieved in 14 of the 16 patients, with three meningiomas shrinking in size after RT. Two meningiomas progressed, one in an area that was outside the radiation field. The visual function had improved in 6 or stabilized in 8 of the 16 patients (88%) and worsened in 2 (12%). Conclusions: Linear accelerator fractionated RT using the multiple noncoplanar dynamic rotation conformal paradigm can be offered to patients with meningiomas that threaten the anterior visual pathways as an adjunct to surgery or as first-line treatment, with results comparable to those reported for other stereotactic RT techniques.

  8. Prospective randomized trial to compare accelerated (six fractions a week radiotherapy against concurrent chemoradiotherapy (using conventional fractionation in locally advanced head and neck cancers

    Manoj Gupta

    2015-01-01

    Full Text Available Background: Concurrent chemoradiation (CCRT is currently considered to be the standard of care in locally advanced head and neck cancer. The optimum radiotherapy schedule for best local control and acceptable toxicity is not yet clear. We aimed at shortening of treatment time by using accelerated radiation, thereby comparing the disease response, loco-regional tumor control and tolerability of accelerated radiation (six fractions per week against CCRT in locally advanced head and neck cancer. Materials and Methods: We conducted the prospective randomized study for a period of 2 years from June 2011 to May 2013 in 133 untreated patients of histologically confirmed squamous cell carcinoma of head and neck. Study group (66 patients received accelerated radiotherapy with 6 fractions per week (66Gy/33#/5½ weeks. Control group (67 patients received CCRT with 5 fractions per week radiation (66 Gy/33#/6½ weeks along with intravenous cisplatin 30 mg/m 2 weekly. Tumor control, survival, acute and late toxicities were assessed. Results: Median overall treatment time was 38 days and 45 days in the accelerated radiotherapy and concurrent chemoradiation arm, respectively. At a median follow up of 12 months, 41 patients (62.1% in the accelerated radiotherapy arm and 47 patients (70.1% in the CCRT arm were disease free (P = 0.402. Local disease control was comparable in both the arms. Acute toxicities were significantly higher in the CCRT arm as compared with accelerated radiotherapy arm. There was no difference in late toxicities between the two arms. Conclusion: We can achieve, same or near to the same local control, with lower toxicities with accelerated six fractions per week radiation compared with CCRT especially for Indian population.

  9. Can pure accelerated radiotherapy given as six fractions weekly be an option in locally advanced carcinoma cervix: Results of a prospective randomized phase III trial

    Mukesh Sharma

    2016-01-01

    Conclusions: Accelerated radiotherapy given as six fractions per week is an effective alternative to concomitant chemoradiation in locally advanced carcinoma cervix and has shown lesser toxicities in our study.

  10. Nelson's syndrome: single centre experience using the linear accelerator (LINAC) for stereotactic radiosurgery and fractionated stereotactic radiotherapy.

    Wilson, Peter J; Williams, Janet R; Smee, Robert I

    2014-09-01

    Nelson's syndrome is a unique clinical phenomenon of growth of a pituitary adenoma following bilateral adrenalectomies for the control of Cushing's disease. Primary management is surgical, with limited effective medical therapies available. We report our own institution's series of this pathology managed with radiation: prior to 1990, 12 patients were managed with conventional radiotherapy, and between 1990 and 2007, five patients underwent stereotactic radiosurgery (SRS) and two patients fractionated stereotactic radiotherapy (FSRT), both using the linear accelerator (LINAC). Tumour control was equivocal, with two of the five SRS patients having a reduction in tumour volume, one patient remaining unchanged, and two patients having an increase in volume. In the FSRT group, one patient had a decrease in tumour volume whilst the other had an increase in volume. Treatment related morbidity was low. Nelson's syndrome is a challenging clinical scenario, with a highly variable response to radiation in our series. PMID:24825407

  11. A randomized study of accelerated fractionation radiotherapy with and without mitomycin C in the treatment of locally advanced head and neck cancer

    Ezzat, M.; Shouman, T.; Zaza, K.;

    2005-01-01

    Objectives: This single-institution study evaluates the feasibility of accelerated fractionation radiotherapy (AF) with and without mitomycin C (MMC) in the treatment of locally advanced head and neck cancer. Patients and Methods: Between May 1998 and October 2001, sixty patients with locally...... advanced stage III and IV of head and neck cancer were randomized into three treatment arms: (1) conventional fractionation radiotherapy (CF) (5 fractions per week); (2) accelerated fractionation radiotherapy (AF) (6 fractions per week); and (3) AF plus Mitomycin C (MMC). Results: The 2-year overall...... survival (OS) of the whole group was 21%. The OS according to treatment arm was 23%, 20%, and 28% in CF, AF, and AF+MMC arms respectively (p<0.19). The 2-year loco-regional control (LC) rate was 22% for the whole group of patients. The LC was 10%, 25%, and 30% for the CF, AF, and AF+MMC respectively (p=0...

  12. Fractionated stereotactic radiotherapy with linear accelerator for uveal melanoma - preliminary Vienna results

    Between June 1997 and February 1998, 21 patients suffering from uveal melanomas have been treated with a sterotactic 6 MeV LINAC (Saturne 43 trademark, General Electric, France) in conjunction with a stereotactic frame system (BrainLAB trademark, Germany). Immobilization of the eye was ensured with an optical fixation system which was proven reliable. During radiotherapy, movements of the irradiated eye were controlled on a monitor and documented by video recording. All patients co-operated very well with the optical fixation system. In 1164 measurements, the median value of horizontal deviation of the diseased eye during treatment was 0.3 mm (range: 0 to 1.3 mm). Median vertical deviation was 0.2 mm (range: 0 to 1.2 mm). For all patients, mean tumor prominence before treatment was 6.0±2.2 mm. In 20 patients, the total dose of 70 Gy (at 80%) was delivered in 5 fractions within 10 days. In one patient with a ciliary body tumor, the total dose of 70 Gy was divided into 7 fractions for better sparing of the anterior eye segment. Results: After a follow-up of at least 6 months, local tumor control was seen in all eyes. Mean tumor thickness reduction after 3, 6 and 9 months was 7%, 13% and 31%, respectively. Up to now, only mild subacute side-effects located in the anterior eye segment have been noticed. (orig.)

  13. Accelerated versus conventional fractionated postoperative radiotherapy for advanced head and neck cancer: Results of a multicenter Phase III study

    Purpose: To determine whether, in the postoperative setting, accelerated fractionation (AF) radiotherapy (RT) yields a superior locoregional control rate compared with conventional fractionation (CF) RT in locally advanced squamous cell carcinomas of the oral cavity, oropharynx, larynx, or hypopharynx. Methods and materials: Patients from four institutions with one or more high-risk features (pT4, positive resection margins, pN >1, perineural/lymphovascular invasion, extracapsular extension, subglottic extension) after surgery were randomly assigned to either RT with one daily session of 2 Gy up to 60 Gy in 6 weeks or AF. Accelerated fractionation consisted of a 'biphasic concomitant boost' schedule, with the boost delivered during the first and last weeks of treatment, to deliver 64 Gy in 5 weeks. Informed consent was obtained. The primary endpoint of the study was locoregional control. Analysis was on an intention-to-treat basis. Results: From March 1994 to August 2000, 226 patients were randomized. At a median follow-up of 30.6 months (range, 0-110 months), 2-year locoregional control estimates were 80% ± 4% for CF and 78% ± 5% for AF (p = 0.52), and 2-year overall survival estimates were 67% ± 5% for CF and 64% ± 5% for AF (p = 0.84). The lack of difference in outcome between the two treatment arms was confirmed by multivariate analysis. However, interaction analysis with median values as cut-offs showed a trend for improved locoregional control for those patients who had a delay in starting RT and who were treated with AF compared with those with a similar delay but who were treated with CF (hazard ratio = 0.5, 95% confidence interval 0.2-1.1). Fifty percent of patients treated with AF developed confluent mucositis, compared with only 27% of those treated with CF (p = 0.006). However, mucositis duration was not different between arms. Although preliminary, actuarial Grade 3+ late toxicity estimates at 2 years were 18% ± 4% and 27% ± 6% for CF and AF

  14. Preliminary comparison of the therapeutic efficacy of accelerated relative to conventional fractionation radiotherapy by treatment of spontaneous canine malignancies

    Purpose/Objective: This study's ultimate goals involve development of an accelerated fractionation (AF) regimen with an integrated final concomitant boost (CB) and examination of factors prognostic of the CB's therapeutic efficacy which could be measured during the initial AF portion to determine for which patients CB should be used. These endpoints can be accurately determined quickly by evaluating the treatment (tx) of spontaneous canine veterinary patient tumors. Because surviving tumor clonogen growth rate increases after radiotherapy (RT) begins, this accelerated repopulation (AR) should be reduced by AF. Furthermore, CB using a small field encompassing only the tumor bed, given as a second daily tx during the last week of RT, should further reduce AR. The initial portion of this project which is nearing completion was designed to determine if incidentally treated normal tissues could tolerate the AF regimen and project whether addition of the tumor bed CB would also be tolerated. Materials and Methods: Currently 20 canine patients with biopsy proven localized tumors have received canine AF radiotherapy given as 3.2Gy/fraction(fx) administered 5 days a week (Mon-Fri) to a total of 15 fxs (48Gy) within 18 elapsed days. RT is given with a 60Co teletherapy unit. Their tumor response, control, survival, and acute normal tissue responses are being directly compared to results we previously obtained from canines receiving a nearly equivalent dose/fx and total dose conventional fractionation (CF) regimen which was given alone or with adjuvant hyperthermia (HT). In that study the canines were stratified by tumor histology and anatomic site and randomly assigned to receive canine CF (3.5Gy/fx, 3 fxs/week [Mon-Wed-Fri] to 14 fxs (49Gy) in an elapsed time of approx. 30 days) either alone or followed weekly by local HT (44 deg. +/- 2 deg. C) for 30 minutes (5 HT fxs). As is currently done, these CF+/-HT patients were followed up to 3 years to quantitate the magnitudes and

  15. A Randomized Study of Accelerated Fractionation Radiotherapy with and Without Mitomycin C in the Treatment of Locally Advanced Head and Neck Cancer

    This single-institution study evaluates the feasibility of accelerated fractionation radiotherapy (AF) with and without mitomycin C (MMC) in thc treatment of locally advanced head and neck cancer. Patients and Methods: Between May 1998 and October 2001, sixty patients with locally advanced stage III and IV of head and neck cancer were randomized into three treatment arms: (I) conventional fractionation radiotherapy (CF) (5 fractions per week); (2) accelerated fractionation radiotherapy (AF) (6 fractions per week); and (3) AF plus Mitomycin C (MMC). The 2-year overall survival (OS) of the whole group was 21 %. The OS according to treatment arm was 23%, 20%. and 28% in CF. AF. and AF+MMC arms respectively (ρ<0. 19). The 2-year loco-regional control (LC) rate was 22% for the whole group of patients. The LC was 10%, 25%. and 30% for the CF, AF, and AF+MMC respectively (ρ=0.27). The only significant parameters for OS and LC were performance status and pre-treatment hemoglobin level. Mucositis grades 3 and 4 occurred in 70% and 90% of the patients in the AF and AF+MMC arm respectively compared to 55% of patients in the CF arm (ρ=0.04). However the addition of MMC did not significantly increase the incidence or severity of mucositis between AF and AF+MMC (ρ=0.13). Hematological toxicity grades 3 and 4 were significantly higher after MMC (occurred in 40% of patients versus 10% and 5% in CF and AF arms respectively, ρ=0.04). There was no statistically significant difference in the incidence of grade 3 dryness of mouth (ρ=0.06). fibrosis (ρ=0.6). or lymphoedema (ρ=0.39) among the three arms. There was a trend for improvement of LC and OS rates with the use or AF and the addition of MMC to AF compared to CF radiotherapy. although the difference was not statistically significant. The small number of the patients in each treatment arm and the inclusion or multiple tumor sites may contribute to these statistically insignificant results. Accordingly we advise to continue

  16. Three-year outcomes of a once daily fractionation scheme for accelerated partial breast irradiation (APBI) using 3-D conformal radiotherapy (3D-CRT)

    The aim of this study was to report 3-year outcomes of toxicity, cosmesis, and local control using a once daily fractionation scheme (49.95 Gy in 3.33 Gy once daily fractions) for accelerated partial breast irradiation (APBI) using three-dimensional conformal radiotherapy (3D-CRT). Between July 2008 and August 2010, women aged ≥40 years with ductal carcinoma in situ or node-negative invasive breast cancer ≤3 cm in diameter, treated with breast-conserving surgery achieving negative margins, were accrued to a prospective study. Women were treated with APBI using 3–5 photon beams, delivering 49.95 Gy over 15 once daily fractions over 3 weeks. Patients were assessed for toxicities, cosmesis, and local control rates before APBI and at specified time points. Thirty-four patients (mean age 60 years) with Tis 0 (n = 9) and T1N0 (n = 25) breast cancer were treated and followed up for an average of 39 months. Only 3% (1/34) patients experienced a grade 3 subcutaneous fibrosis and breast edema and 97% of the patients had good/excellent cosmetic outcome at 3 years. The 3-year rate of ipsilateral breast tumor recurrence (IBTR) was 0% while the rate of contralateral breast events was 6%. The 3-year disease-free survival (DFS), overall survival (OS), and breast cancer-specific survival (BCSS) was 94%, 100%, and 100%, respectively. Our novel accelerated partial breast fractionation scheme of 15 once daily fractions of 3.33 Gy (49.95 Gy total) is a remarkably well-tolerated regimen of 3D-CRT-based APBI. A larger cohort of patients is needed to further ascertain the toxicity of this accelerated partial breast regimen

  17. Predicting the Effect of Accelerated Fractionation in Postoperative Radiotherapy for Head and Neck Cancer Based on Molecular Marker Profiles: Data From a Randomized Clinical Trial

    Purpose: To determine the prognostic and predictive values of molecular marker expression profiles based on data from a randomized clinical trial of postoperative conventional fractionation (p-CF) therapy versus 7-day-per-week postoperative continuous accelerated irradiation (p-CAIR) therapy for squamous cell cancer of the head and neck. Methods and Materials: Tumor samples from 148 patients (72 p-CF and 76 p-CAIR patients) were available for molecular studies. Immunohistochemistry was used to assess levels of EGFR, nm23, Ki-67, p-53, and cyclin D1 expression. To evaluate the effect of fractionation relative to the expression profiles, data for locoregional tumor control (LRC) were analyzed using the Cox proportional hazard regression model. Survival curves were compared using the Cox f test. Results: Patients who had tumors with low Ki-67, low p-53, and high EGFR expression levels and oral cavity/oropharyngeal primary cancer sites tended to benefit from p-CAIR. A joint score for the gain in LRC from p-CAIR based of these features was used to separate the patients into two groups: those who benefited significantly from p-CAIR with respect to LRC (n = 49 patients; 5-year LRC of 28% vs. 68%; p = 0.01) and those who did not benefit from p-CAIR (n = 99 patients; 5-year LRC of 72% vs. 66%; p = 0.38). The nm23 expression level appeared useful as a prognostic factor but not as a predictor of fractionation effect. Conclusions: These results support the studies that demonstrate the potential of molecular profiles to predict the benefit from accelerated radiotherapy. The molecular profile that favored accelerated treatment (low Ki-67, low p-53, and high EGFR expression) was in a good accordance with results provided by other investigators. Combining individual predictors in a joint score may improve their predictive potential.

  18. High-dose accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine and carboplatin chemotherapy in locally advanced non-small-cell lung cancer: a feasibility study

    Increasing the radiotherapy dose can result in improved local control for non-small-cell lung cancer (NSCLC) and can thereby improve survival. Accelerated hypofractionated radiotherapy can expose tumors to a high dose of radiation in a short period of time, but the optimal treatment regimen remains unclear. The purpose of this study was to evaluate the feasibility of utilizing high-dose accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine (NVB) and carboplatin (CBP) chemotherapy for the treatment of local advanced NSCLC. Untreated patients with unresectable stage IIIA/IIIB NSCLC or patients with a recurrence of NSCLC received accelerated hypofractionated three-dimensional conformal radiotherapy. The total dose was greater than or equal to 60 Gy. The accelerated hypofractionated radiotherapy was conducted once daily at 3 Gy/fraction with 5 fractions per week, and the radiotherapy was completed in 5 weeks. In addition to radiotherapy, the patients also received at least 1 cycle of a concurrent two-drug chemotherapy regimen of NVB and CBP. A total of 26 patients (19 previously untreated cases and 7 cases of recurrent disease) received 60Gy-75Gy radiotherapy with concurrent chemotherapy. All of the patients underwent evaluations for toxicity and preliminary therapeutic efficacy. There were no treatment-related deaths within the entire patient group. The major acute adverse reactions were radiation esophagitis (88.5%) and radiation pneumonitis (42.3%). The percentages of grade III acute radiation esophagitis and grade III radiation pneumonitis were 15.4% and 7.7%, respectively. Hematological toxicities were common and did not significantly affect the implementation of chemoradiotherapy after supportive treatment. Two patients received high dose of 75 Gy had grade III late esophageal toxicity, and none had grade IV and above. Grade III and above late lung toxicity did not occur. High-dose accelerated

  19. Elective lymph node irradiation late course accelerated hyper-fractionated radiotherapy plus concurrent cisplatin-based chemotherapy for esophageal squamous cell carcinoma: a phase II study

    In this phase II study, we evaluated the efficacy, toxicity, and patterns of failure of elective lymph node irradiation (ENI) late course accelerated hyper-fractionated radiotherapy (LCAHRT) concurrently with cisplatin-based chemotherapy (CHT) for esophageal squamous cell carcinoma (ESCC). Patients with clinical stage II-IVa (T1-4N0-1M0 or M1a) ESCC were enrolled between 2004 and 2011. Radiation therapy (RT) comprised two courses: The first course of radiation covered the primary and metastatic regional tumors and high risk lymph nodal regions, given at 2 Gy per fraction for a dose of 40 Gy. In the second course, LCAHRT was delivered to the boost volume twice a day for an additional 19.6 Gy in 7 treatment days, using 1.4 Gy per fraction. Two cycles of CHT were given at the beginning of RT. The median age and Karnofsky performance status were 63 years and 80, respectively. The American Joint Committee on Cancer stage was II in 14 (20.6%) patients, III in 32 (47.1%), and IVa in 22 (32.3%). With a median follow-up of 18.5 months, the overall survival at 1-, 3-, 5-year were 75.5%, 46.5%, 22.7% for whole group patients, versus 78.6%, 49.4%, 39.9% for patients with stage II–III. The patterns of first failure from local recurrence, regional failure, and distant metastasis were seen in 20.6%, 17.6%, and 19.1%, respectively. The most frequent acute high-grade (≥ 3) toxicities were esophagitis and leucopenia, occurred in 26.4% and 32.4%. ENI LCAHRT concurrently with CHT was appeared to be an effective regimen for ESCC patient with a favorable and tolerated profile. Further observation with longer time and randomized phase III trial is currently underway.

  20. Single fraction radiotherapy versus multiple fraction radiotherapy for bone metastases in prostate cancer patients: comparative effectiveness

    External beam radiotherapy (EBRT) is an effective treatment for symptomatic bone metastases from a variety of primary malignancies. Previous meta-analyses and systematic reviews have reported on the efficacy of EBRT on bone metastases from multiple primaries. This review is focused on the comparative effectiveness of single fraction radiotherapy versus multiple fraction radiotherapy for bone metastases in prostate cancer patients

  1. What next in fractionated radiotherapy

    Trends in models for predicting the total dose required to produce tolerable normal-tissue injury can be seen by the progression from the ''cube root law'', through Strandqvist's slope of 0.22, to NSD, TDF and CRE which have separate time and fraction number exponents, to even better approximations now available. The dose-response formulae that can be used to define the effect of fraction size (and number) include (1) the linear quadratic (LQ) model (2) the two-component (TC) multi-target model and (3) repair-misrepair models. The LQ model offers considerable convenience, requires only two parameters to be determined, and emphasizes the difference between late and early normal-tissue dependence on dose per fraction first shown by exponents greater than the NSD slope of 0.24. Exponents of overall time, e.g. Tsup(0.11), yield the wrong shape of time curve, suggesting that most proliferating occurs early, although it really occurs after a delay depending on the turnover time of the tissue. Improved clinical results are being sought by hyperfractionation, accelerated fractionation, or continuous low dose rate irradiation as in interstitial implants. (U.K.)

  2. Neurocognitive outcome in brain metastases patients treated with accelerated-fractionation vs. accelerated-hyperfractionated radiotherapy: an analysis from Radiation Therapy Oncology Group Study 91-04

    Purpose: To evaluate neurocognitive outcome as measured by the Mini-Mental Status Examination (MMSE) among patients with unresectable brain metastases randomly assigned to accelerated fractionation (AF) vs. accelerated hyperfractionated (AH) whole-brain radiation therapy (WBRT). Methods and Materials: The Radiation Therapy Oncology Group (RTOG) accrued 445 patients with unresectable brain metastases to a Phase III comparison of AH (1.6 Gy b.i.d. to 54.4 Gy) vs. AF (3 Gy q.d. to 30 Gy). All had a KPS of ≥ 70 and a neurologic function status of 0-2. Three hundred fifty-nine patients had MMSEs performed and were eligible for this analysis. Changes in the MMSE were analyzed according to criteria previously defined in the literature. Results: The median survival was 4.5 months for both arms. The average change in MMSE at 2 and 3 months was a drop of 1.4 and 1.1, respectively, in the AF arm as compared to a drop of 0.7 and 1.3, respectively, in the AH arm (p=NS). Overall, 91 patients at 2 months and 23 patients at 3 months had both follow-up MMSE and computed tomography/magnetic resonance imaging documentation of the status of their brain metastases. When an analysis was performed taking into account control of brain metastases, a significant effect on MMSE was observed with time and associated proportional increase in uncontrolled brain metastases. At 2 months, the average change in MMSE score was a drop of 0.6 for those whose brain metastases were radiologically controlled as compared to a drop of 1.9 for those with uncontrolled brain metastases (p=0.47). At 3 months, the average change in MMSE score was a drop of 0.5 for those whose brain metastases were radiologically controlled as compared to a drop of 6.3 for those with uncontrolled brain metastases (p=0.02). Conclusion: Use of AH as compared to AF-WBRT was not associated with a significant difference in neurocognitive function as measured by MMSE in this patient population with unresectable brain metastases and

  3. Second Study of Hyper-Fractionated Radiotherapy

    R. Jacob

    1999-01-01

    Full Text Available Purpose and Method. Hyper-fractionated radiotherapy for treatment of soft tissue sarcomas is designed to deliver a higher total dose of radiation without an increase in late normal tissue damage. In a previous study at the Royal Marsden Hospital, a total dose of 75 Gy using twice daily 1.25 Gy fractions resulted in a higher incidence of late damage than conventional radiotherapy using 2 Gy daily fractions treating to a total of 60 Gy. The current trial therefore used a lower dose per fraction of 1.2 Gy and lower total dose of 72 Gy, with 60 fractions given over a period of 6 weeks.

  4. Theoretical exploration on ultra-fractionated radiotherapy

    This study based on the hyper-radiosensitivity (HRS) effect, a new tumour radiotherapy method - ultra-fractionation has been devised. Compared with conventional fractionation, the dose per fraction is decreased from 2Gy to 0.2 ∼ 0.5Gy for the ultra-fractionation. Although the amount of fractions is increased in order to reach the same therapeutic efficacy, the total dose is significantly reduced

  5. Dose escalation of accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine and carboplatin chemotherapy in unresectable stage III non-small-cell lung cancer: a phase I trial

    Accelerated hypofractionated radiotherapy can shorten total treatment time and overcome the accelerated repopulation of tumour cells during radiotherapy. This therapeutic approach has demonstrated good efficacy in the treatment of locally advanced non-small-cell lung cancer (NSCLC). However, the optimal fractionation scheme remains uncertain. The purpose of this phase I trial was to explore the maximum tolerated dose (MTD) of accelerated hypofractionated three-dimensional conformal radiotherapy (3-DCRT) (at 3 Gy/fraction) administered in combination with concurrent vinorelbine (NVB) and carboplatin (CBP) chemotherapy for unresectable stage III NSCLC. Previously untreated cases of unresectable stage III NSCLC received accelerated hypofractionated 3-DCRT, delivered at 3 Gy per fraction, once daily, with five fractions per week. The starting dose was 66 Gy and an increment of 3 Gy was utilized. Higher doses continued to be tested in patient groups until the emergence of dose-limiting toxicity (DLT). The MTD was regarded as the dose that was one step below the dose at which DLT occurred. Patients received at least one cycle of a concurrent two-drug chemotherapy regimen of NVB and CBP. A total of 13 patients were enrolled and progressed through three dose escalation groups: 66 Gy, 69 Gy, and 72 Gy. No treatment-related deaths occurred. The major adverse events included radiation oesophagitis, radiation pneumonitis, and neutropenia. Nausea, fatigue, and anorexia were commonly observed, although the magnitude of these events was typically relatively minor. Among the entire group, four instances of DLT were observed, including two cases of grade 3 radiation oesophagitis, one case of grade 3 radiation pneumonitis, and one case of grade 4 neutropenia. All of these cases of DLT occurred in the 72 Gy group. Therefore, 72 Gy was designated as the DLT dose level, and the lower dose of 69 Gy was regarded as the MTD. For unresectable stage III NSCLC 69 Gy (at 3 Gy/fraction) was

  6. Fractionated stereotactic radiotherapy for acoustic neuromas

    Purpose: When compared with radiosurgery, fractionated stereotactic radiotherapy for acoustic neuroma (AN) offers escalation of the tumor dose and potential sparing of auditory and facial nerve functions. Methods and Materials: Between 1996 and 2001, 249 consecutive patients have received fractionated stereotactic radiotherapy for AN. One hundred twenty-five patients had follow-up >1 year and were the subject of this report. A noninvasive, repeat-fixation mask allowed simulation by way of spiral CT. Two distinct schedules for total dose and fractionation were used. For an AN 3), patients received 25 Gy given in 5 consecutive daily fractions of 5 Gy (111 patients), and for ANs ≥3.0 cm (volume 8.1 ± 1.2 cm3), patients received 30 Gy given in 10 fractions of 3 Gy (14 patients). Results: The percentage of decrease in tumor size was 12% ± 2% (range 0-100%) vs. 13% ± 3% (range 0-38%) for the 25 Gy vs. 30 Gy regimens, respectively. No patient had growth of the AN or developed facial weakness. Two patients developed transient decreases in facial sensation. The rates of hearing preservation were similar for the larger and smaller tumors. Conclusion: Fractionated stereotactic radiotherapy may preserve normal function and control both small and large ANs

  7. Avoidance of treatment interruption: an unrecognized benefit of accelerated radiotherapy in oropharyngeal carcinomas?

    Allal, Abdelkarim Said; De Pree, Christian; Dulguerov, Pavel; Bieri, Sabine; Maire, Daphne Isabel; Kurtz, John

    1999-01-01

    To assess the impact of treatment interruption on the potential gain in locoregional control obtained with accelerated radiotherapy (RT) compared with conventionally fractionated RT in patients with oropharyngeal carcinomas.

  8. Biological dose volume histograms during conformal hypofractionated accelerated radiotherapy for prostate cancer

    Radiobiological data suggest that prostate cancer has a low α/β ratio. Large radiotherapy fractions may, therefore, prove more efficacious than standard radiotherapy, while radiotherapy acceleration should further improve control rates. This study describes the radiobiology of a conformal hypofractionated accelerated radiotherapy scheme for the treatment of high risk prostate cancer. Anteroposterior fields to the pelvis deliver a daily dose of 2.7 Gy, while lateral fields confined to the prostate and seminal vesicles deliver an additional daily dose of 0.7 Gy. Radiotherapy is accomplished within 19 days (15 fractions). Dose volume histograms, calculated for tissue specific α/β ratios and time factors, predict a high biological dose to the prostate and seminal vesicles (77-93 Gy). The biological dose to normal pelvic tissues is maintained at standard levels. Radiobiological dosimetry suggests that, using hypofractionated and accelerated radiotherapy, high biological radiation dose can be given to the prostate without overdosing normal tissues

  9. Final results of the randomized phase III CHARTWEL-trial (ARO 97-1) comparing hyperfractionated-accelerated versus conventionally fractionated radiotherapy in non-small cell lung cancer (NSCLC)

    Background: Continuous hyperfractionated accelerated radiotherapy (CHART) counteracts repopulation and may significantly improve outcome of patients with non-small-cell lung cancer (NSCLC). Nevertheless high local failure rates call for radiation dose escalation. We report here the final results of the multicentric CHARTWEL trial (CHART weekend less, ARO 97-1). Patients and methods: Four hundred and six patients with NSCLC were stratified according to stage, histology, neoadjuvant chemotherapy and centre and were randomized to receive 3D-planned radiotherapy to 60 Gy/40 fractions/2.5 weeks (CHARTWEL) or 66 Gy/33 fractions/6.5 weeks (conventional fractionation, CF). Results: Overall survival (OS, primary endpoint) at 2, 3 and 5 yr was not significantly different after CHARTWEL (31%, 22% and 11%) versus CF (32%, 18% and 7%; HR 0.92, 95% CI 0.75-1.13, p = 0.43). Also local tumour control rates and distant metastases did not significantly differ. Acute dysphagia and radiological pneumonitis were more pronounced after CHARTWEL, without differences in clinical signs of pneumopathy. Exploratory analysis revealed a significant trend for improved LC after CHARTWEL versus CF with increasing UICC, T or N stage (p = 0.006-0.025) and after neoadjuvant chemotherapy (HR 0.48, 0.26-0.89, p = 0.019). Conclusions: Overall, outcome after CHARTWEL or CF was not different. The lower total dose in the CHARTWEL arm was compensated by the shorter overall treatment time, confirming a time factor for NSCLC. The higher efficacy of CHARTWEL versus CF in advanced stages and after chemotherapy provides a basis for further trials on treatment intensification for locally advanced NSCLC.

  10. Accelerated radiotherapy in advanced head and neck cancer

    The purpose of the study is to present the reasons for introducing concomitant boost accelerated radiotherapy (CBAR) and its practical aspects at advanced head and neck carcinomas (HNC). Accelerated clonogenic repopulation of the tumor during radiotherapy necessitates its termination within the shortest possible term. The differentiated effect of the fractionated dose on both early and late response of tissues requires the use of several smaller daily fractions with an interval between exceeding six hours during all the time of radiotherapy or a part of it. If there is no data about earlier kinetics of the tumor cells, schemes with total dose 69-72 Gy are given preference. The practical aspects of CBAR also are presented: 1. specificity of the clinical target volume (ICRU 50) considering the requirements for beam and fields; 2. irradiation techniques most frequently used and 3. the method of patient immobilization. The characteristic features of CBAR are also discussed: 1. The primary tumor and its subclinical diffusion are irradiated in standard fields or in such with exclusion of the spinal cord at dose up to 54 in 30 fractions for 5.5 weeks. During the first two days, two daily fractions at six-hours interval are delivered with partial exclusion of the spinal cord. The primary tumor is given during the last 2.5 weeks up to total dose 69-72 Gy with a second daily fraction of 1.5 Gy six hours after the first one; 2. The current concepts for spinal cord radiation tolerance and very high risk of transverse myelitis in some accelerated radiotherapeutical schemes are also discussed. The therapeutic approach described is based on the experience got from the conventional fractionation; 3. Without neglecting enhanced acute toxicity CBAR is recommended as a well tolerated radiotherapeutical method

  11. Fractionated radiotherapy in the treatment of neuroblastoma

    Purpose: To evaluate the benefit of radiation therapy for metastatic neuroblastoma patients. Methods and Materials: From September 1970 to March 1995, 90 patients with neuroblastoma were treated with fractionated radiotherapy. We looked at 42 patients with metastatic disease and 170 sites that were treated for the following indications: pain, mass effect, mass/cosmesis, adjuvant, and consolidation. Data collected includes age at diagnosis, sex, site of radiation, dose, fractionation, purpose of treatment, response, duration of local control, status at follow-up, and date of death. Results: Doses ranged from 100 cGy to 5000 cGy with a median dose of 2020 cGy. Median survival for this group of patients was 23.7 months with a maximum survival of 175.8 months and a minimum survival of two months. Patients whose sites were treated from 1970 - 1981 had a median survival of 22 months and a median dose of 2000 cGy compared to a survival of 26 months and a median dose of 1140 cGy for patients treated from 1981 - 1995. In patients treated for gross disease, 53% had a complete response to treatment and 46% had a partial response. There was a 16% recurrence rate in sites treated. Median time to failure was five months, although this ranged from a minimum of one month to a maximum of 119 months. Median dose of the sites of failure was 2000 cGy. Thirty-three percent of sites were treated within two months of patients' death. Conclusion: Fractionated radiotherapy is an effective treatment modality for palliation of metastatic neuroblastoma. Along with other modern treatments, including chemotherapy, it appears a total dose of around 1200 cGy is sufficient for palliation of most metastatic sites

  12. Fractionated stereotactically guided radiotherapy for pharmacoresistant epilepsy

    Aim: This prospective study evaluated the efficiency of fractionated stereotactically guided radiotherapy as a treatment of pharmacoresistant temporal lobe epilepsy. Patients and Methods: Inclusion criteria were patients aged between 17 and 65 years with one-sided temporally located focus, without sufficient epilepsy control by, antiepileptic drugs or neurosurgery. Between 1997 and 1999, two groups of six patients each were treated with 21 Gy (7 times 3 Gy) and 30 Gy (15 times 2 Gy). Study end points were seizure frequency, intensity, seizure length and neuropsychological parameters. Results: All patients experienced a marked reduction in seizure frequency. The mean reduction of seizures was 37% (range 9-77%, i.e. seizures reduced from a monthly mean number of 11.75 to 7.52) at 18 months following radiation treatment and 46% (23-94%, i.e. 0.2-23 seizures per month) during the whole follow-up time. Seizure length was reduced in five out of eleven patients and intensity of seizures in seven out of eleven patients. Conclusion: Radiotherapy was identified as safe and effective for pharmacoresistant epilepsy since a very good reduction of seizure frequency was observed. It is no substitute for regular use of antiepileptic drugs, but means an appropriate alternative for patients with contraindication against neurosurgery or insufficient seizure reduction after neurosurgery. (orig.)

  13. Hyperfractionated or accelerated radiotherapy in head and neck cancer: a meta-analysis

    Bourhis, J.; Overgaard, Jens; Audry, H.;

    2006-01-01

    BACKGROUND: Several trials have studied the role of unconventional fractionated radiotherapy in head and neck squamous cell carcinoma, but the effect of such treatment on survival is not clear. The aim of this meta-analysis was to assess whether this type of radiotherapy could improve survival......-specified categories: hyperfractionated, accelerated, and accelerated with total dose reduction. FINDINGS: 15 trials with 6515 patients were included. The median follow-up was 6 years. Tumours sites were mostly oropharynx and larynx; 5221 (74%) patients had stage III-IV disease (International Union Against Cancer...... radiotherapy (2% with accelerated fractionation without total dose reduction and 1.7% with total dose reduction at 5 years, p=0.02). There was a benefit on locoregional control in favour of altered fractionation versus conventional radiotherapy (6.4% at 5 years; p<0.0001), which was particularly efficient in...

  14. Accelerator dynamics of a fractional kicked rotor

    Iomin, A.

    2006-01-01

    It is shown that the Weyl fractional derivative can quantize an open system. A fractional kicked rotor is studied in the framework of the fractional Schrodinger equation. The system is described by the non-Hermitian Hamiltonian by virtue of the Weyl fractional derivative. Violation of space symmetry leads to acceleration of the orbital momentum. Quantum localization saturates this acceleration, such that the average value of the orbital momentum can be a direct current and the system behaves ...

  15. European organization for research on treatment of cancer trials using radiotherapy with multiple fractions per day

    During the past decade (1976-1986), radiotherapy with altered fractionation schemes using multiple fractions per day (MFD) was the major field of the clinical research undertaken in the EORTC Cooperative Group of Radiotherapy. Some of its participating institutions (Portsmouth, Dijon, Leuven, Amsterdam, Rome) performed pilot studies in the midseventies in more than 400 patients. Then largely based upon the previous institutional experiences, EORTC-labelled phase II and III were activated: 1,678 patients have been entered in 8 trials during the period 1978-1987. In order to summarize these clinical experiments covering various fields of tumor pathology, radiotherapy schemes are divided according to the type of altered fractionation: pure hyperfractionation, accelerated fractionation and mixed hyprfractionated and accelerated schemes

  16. Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy

    Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

    2016-01-01

    Background Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the no...

  17. Fractionated stereotactic radiotherapy for recurrent small cell lung cancer brain metastases after whole brain radiotherapy

    Objective: Evaluation the Fractionated Stereotactic Radiotherapy (FSRT) for the patients with small-cell lung cancer (SCLC) after the whole brain radiotherapy (WBRT) failure. Methods: We retrospectively analyzed 35 patients with brain metastases from small-cell lung cancer treated with linear accelerator FSRT after the WBRT failure. Multivariate analysis was used to determine significant prognostic factor related to survival. Results: The following-up rate was 100%. The median following-up time was 11 months. The median over-all survival (OS) time was 10.3(1 -30) months after FSRT. Controlled extra cranial disease was the only identified significant predictor of increased median OS time (χ2 =4.02, P =0.045 ). The median OS time from the diagnosis of brain metastasis was 22 (6 - 134 ) months. 14 patients died from brain metastasis, 14 from extra-cranial progression, 1 from leptomeningeal metastases, and 3 from other causes. Local control at 6 months and 12 months was 91% and 76%, respectively. No significant late complications. New brain metastases outside of the treated area developed in 17% of patients at a median time of 4(2 -20) months; all patients had received previous WBRT. Conclusions: Fractionated stereotactic radiotherapy was safe and effective treatment for recurrent small-cell lung carcinoma brain metastases. (authors)

  18. Fractionated Stereotactic Radiotherapy for Facial Nerve Schwannomas.

    Shi, Wenyin; Jain, Varsha; Kim, Hyun; Champ, Colin; Jain, Gaurav; Farrell, Christopher; Andrews, David W; Judy, Kevin; Liu, Haisong; Artz, Gregory; Werner-Wasik, Maria; Evans, James J

    2016-02-01

    Purpose Data on the clinical course of irradiated facial nerve schwannomas (FNS) are lacking. We evaluated fractionated stereotactic radiotherapy (FSRT) for FNS. Methods Eight consecutive patients with FNS treated at our institution between 1998 and 2011 were included. Patients were treated with FSRT to a median dose of 50.4 Gy (range: 46.8-54 Gy) in 1.8 or 2.0 Gy fractions. We report the radiographic response, symptom control, and toxicity associated with FSRT for FNS. Results The median follow-up time was 43 months (range: 10-75 months). All patients presented with symptoms including pain, tinnitus, facial asymmetry, diplopia, and hearing loss. The median tumor volume was 1.57 cc. On the most recent follow-up imaging, five patients were noted to have stable tumor size; three patients had a net reduction in tumor volume. Additionally, six patients had improvement in clinical symptoms, one patient had stable clinical findings, and one patient had worsened House-Brackmann grade due to cystic degeneration. Conclusion FSRT treatment of FNS results in excellent control of growth and symptoms with a small rate of radiation toxicity. Given the importance of maintaining facial nerve function, FSRT could be considered as a primary management modality for enlarging or symptomatic FNS. PMID:26949592

  19. Tissue kinetics in mouse tongue mucosa during daily fractionated radiotherapy

    The purpose of the present investigation was to quantify cell flux between the distinct layers of the epithelial lining of the ventral surface of mouse tongue during daily fractionated radiotherapy. In tongue epithelium of untreated mice, the minimum residence time of cells in the germinal layer is 2-3 days. Migration through the functional layers requires an additional 2-3 days before labelled cells are observed in the most superficial layer of nucleated cells. A plateau in LI is observed for several days post-labelling in control epithelium, indicating an equilibrium between loss and proliferation of labelled cells. During fractionated radiotherapy, the minimum time from division to occurrence of labelled cells in the stratum lucidum is less than 2 days, and hence significantly shorter than in control epithelium. In contrast to untreated epithelium, no plateau in the germinal layer LI is seen, indicating that frequently both labelled daughters from dividing labelled cells are being lost from this compartment. In conclusion, the present data support a recently described model of radiation-induced accelerated repopulation in squamous epithelia, which postulates that the majority of damaged cells undergoes abortive divisions resulting in two differentiating daughters. (Author)

  20. Immediate side effects of large fraction radiotherapy

    Devereux, S.; Hatton, M.Q.F.; Macbeth, F.R. [Glasgow Western Infirmary (United Kingdom)

    1997-09-01

    The use of hypofractionated radiotherapy regiments is becoming more widely recognized in the palliation of non-small cell lung carcinoma (NSCLC). Anecdoctal reports of chest pain, rigors and fevers in the hours that follow radiotherapy led us to perform a survey estimating the frequency and severity of these symptoms following treatment to the thorax. We conclude that patients receiving palliative radiotherapy for bronchial carcinoma often develop significant symptoms in the hours following treatment. The timing and duration suggest a relationship with the radiotherapy, and we feel that patients should be warned of the possible occurrence of these symptoms. (author).

  1. Accelerated radiotherapy for advanced laryngeal cancer

    The purpose of this study was to evaluate a single institution's outcome for patients with advanced laryngeal cancer treated with accelerated radiotherapy (RT). Fifty-eight patients with advanced laryngeal cancer were treated with curative intent with accelerated RT during the period 1990-1998. Patients received radiotherapy alone or with induction chemotherapy. The 5-year local control (LC) and loco-regional control (LRC) probabilities were both 49% for T3 and 75% for T4 tumors. The 5-year disease-free survival probability was 46% and 68% and overall survival probability was 30% and 39% for T3 and T4 tumors respectively. No significant statistical difference in outcome was found, either between T3 and T4 tumors, or between patients who received induction chemotherapy and those who did not. The treatment results for advanced laryngeal cancer at this institution were comparable to those reported in the literature. The results for T3 and T4 were similar. T4 classification alone should not be an exclusion criterion for larynx preservation. Overall survival was poor, partly because of a high incidence of deaths from intercurrent diseases

  2. Accelerated radiotherapy for advanced laryngeal cancer

    Haugen, Hedda; Mercke, Claes [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Oncology; Johansson, Karl-Axel [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Radiophysics; Ejnell, Hasse; Edstroem, Staffan [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Oto-Rhino-Laryngology

    2005-07-01

    The purpose of this study was to evaluate a single institution's outcome for patients with advanced laryngeal cancer treated with accelerated radiotherapy (RT). Fifty-eight patients with advanced laryngeal cancer were treated with curative intent with accelerated RT during the period 1990-1998. Patients received radiotherapy alone or with induction chemotherapy. The 5-year local control (LC) and loco-regional control (LRC) probabilities were both 49% for T3 and 75% for T4 tumors. The 5-year disease-free survival probability was 46% and 68% and overall survival probability was 30% and 39% for T3 and T4 tumors respectively. No significant statistical difference in outcome was found, either between T3 and T4 tumors, or between patients who received induction chemotherapy and those who did not. The treatment results for advanced laryngeal cancer at this institution were comparable to those reported in the literature. The results for T3 and T4 were similar. T4 classification alone should not be an exclusion criterion for larynx preservation. Overall survival was poor, partly because of a high incidence of deaths from intercurrent diseases.

  3. Late course accelerated hyperfractionation radiotherapy for nasopharyngeal carcinoma

    Objective: To study the efficacy of late course accelerated fractionation (LCAF) radio- therapy in the treatment of nasopharyngeal carcinoma(NPC). The end-po s were local control, radiation-induced complications, factors influencing survival. Methods: From December 1995 to April 1998, 178 NPC patients were admitted for radiation treatment. The radiation beam used was 60Co γ or 6 MV X-ray. For the first two-thirds of the treatment, two daily fractions of 1.2 Gy were given to the primary lesion , with an interval of ≥6 hours, 5 days per week to a total dose of 48 Gy/40 fractions, over a period of 4 weeks. For the last one third of the treatment, i. e. beginning from the 5th week, an accelerated hyperfractionation schedule was carried out. The dose per fraction was increased to 1.5 Gy, 2 fractions per day with an interval of ≥6 hours, the total dose for this part of the protocol was 30 Gy/20 fractions over 2 weeks. Thus the total dose was 78 Gy in 60 fractions in 6 weeks. Results: All patients completed the treatment. Acute mucositis: none in 2 patients, Grade 1 in 43 , Grade 2 in 78, Grade 3 in 52, and Grade 4 in 3 patients. Local control rate: the 5 -year nasopharyngeal local control rate was 87.7%, and the cervical lymph node local control rate was 85.7%. The 5-year distant metastasis rate was 26.1%, and 5-year survivals was 67.9%. Sixteen patients had radiation-induced cranial nerve palsy. Conclusions: With this treatment schedule, patient's tolerance is good, local control and 5 year survivals are better than control groups of conventional fractionation and hyperfractionation radiotherapy. Radiation-related late complication does not increase. Randomized clinical trials are being carried out to further confirm the efficacy of LCAF for nasopharyngeal carcinoma. (authors)

  4. Treatment accuracy of fractionated stereotactic radiotherapy

    Background and purpose: To assess the geometric accuracy of the delivery of fractionated stereotactic radiotherapy (FSRT) for brain tumours using the Gill-Thomas-Cosman (GTC) relocatable frame. Accuracy of treatment delivery was measured via portal images acquired with an amorphous silicon based electronic portal imager (EPI). Results were used to assess the existing verification process and to review the current margins used for the expansion of clinical target volume (CTV) to planning target volume (PTV). Patients and methods: Patients were immobilized in a GTC frame. Target volume definition was performed on localization CT and MRI scans and a CTV to PTV margin of 5 mm (based on initial experience) was introduced in 3D. A Brown-Roberts-Wells (BRW) fiducial system was used for stereotactic coordinate definition. The existing verification process consisted of an intercomparison of the coordinates of the isocentres and anatomy between the localization and verification CT scans. Treatment was delivered with 6 MV photons using four fixed non-coplanar conformal fields using a multi-leaf collimator. Portal imaging verification consisted of the acquisition of orthogonal images centred through the treatment isocentre. Digitally reconstructed radiographs (DRRs) created from the CT localization scans were used as reference images. Semi-automated matching software was used to quantify set up deviations (displacements and rotations) between reference and portal images. Results: One hundred and twenty six anterior and 123 lateral portal images were available for analysis for set up deviations. For displacements, the total errors in the cranial/caudal direction were shown to have the largest SD's of 1.2 mm, while systematic and random errors reached SD's of 1.0 and 0.7 mm, respectively, in the cranial/caudal direction. The corresponding data for rotational errors (the largest deviation was found in the sagittal plane) was 0.7 deg. SD (total error), 0.5 deg. (systematic) and 0

  5. Research on inter-fraction and intra-fraction motion of crystalline lens in radiotherapy

    Shu-ming YANG

    2013-03-01

    Full Text Available Objective  To investigate the range of inter-fraction and intra-fraction motion of crystalline lens in radiotherapy. Methods  The CT and MRI images of 17 patients were registered, and the profile of crystalline lens was delineated to determine the respective center coordinates, thus simulating and analyzing inter-fraction and intra-fraction motion of lens in radiotherapy. Results  Both left and right lens moved in different degree during both inter-or intra-fraction phase. The range of lens movement was larger in inter-fraction than in intra-fraction phase in all directions. Conclusion  When radiotherapy is given in the free state, considering the distance of lens movement alone in inter-and intra-fraction and without considering the setup error, the lens planning organs at risk should increase 1.5mm outside the lens boundary.

  6. Status of hypo fractionated radiotherapy in breast cancer

    It has been assumed that in the case of a majority of tumours hypo fractionation radiotherapy is of limited value because it negatively affected the ratio of curability to late adverse effects. However, there now exists data to suggest that hypo fractionation may be advisory in breast cancer. The author presents a number of recently published and currently ongoing trials, which may provide evidence for the use of hypo fractionated radiotherapy in breast cancer patients. The possible implications for primary breast cancer are that modest increase in fraction size combined with reduction in treatment time may translate into worthwhile gains in tumour control, without enhanced late normal tissue injuries. This may affect future decision-making in the course of radiotherapy for breast cancer if the ongoing trials are confirmatory. (author)

  7. Local radiotherapeutic management of ependymomas with fractionated stereotactic radiotherapy (FSRT)

    To assess the role of Fractionated Stereotactic Radiotherapy (FSRT) in the management of ependymomas. From January 1992 to July 2003, FSRT was performed in 19 patients with histologically confirmed ependymomas. The median age was 15 years, 5 patients were younger than 4 years of age. Twelve patients received FSRT as primary postoperative radiotherapy after surgical resection. In 6 patients irradiation of the posterior fossa was performed with a local boost to the tumor bed, and in 4 patients the tumor bed only was irradiated. In 7 patients FSRT was performed as re-irradiation for tumor progression. This patient group was analyzed separately. A median dose of 54 Gy was prescribed in a median fractionation of 5 × 1.8 Gy per week for primary RT using 6 MeV photons with a linear accelerator. For FSRT as re-irradiation, a median dose of 36 Gy was applied. All recurrent tumors were localized within the former RT-field. The 5- and 10-year overall survival rates were 77% and 64%, respectively. Patients treated with FSRT for primary irradiation showed an overall survival of 100% and 78% at 3 and 5 years after irradiation of the posterior fossa with a boost to the tumor bed, and a survival rate of 100% at 5 years with RT of the tumor bed only. After re-irradiation with FSRT, survival rates of 83% and 50% at 3-and 5 years, respectively, were obtained. Progression-free survival rates after primary RT as compared to re-irradiation were 64% and 60% at 5 years, respectively. FSRT was well tolerated by all patients and could be completed without interruptions due to side effects. No severe treatment related toxicity > CTC grade 2 for patients treated with FSRT could be observed. The present analysis shows that FSRT is well tolerated and highly effective in the management of ependymal tumors. The rate of recurrences, especially at the field border, is not increased as compared to conventional radiotherapy consisting of craniospinal irradiation and a local boost to the posterior

  8. Dosimetric effect of intra-fractional and inter-fractional target motion in lung cancer radiotherapy techniques

    Teerthraj Verma

    2015-12-01

    Full Text Available Purpose: The purpose of present study was to experimentally evaluate the dosimetric uncertainties in 3-dimensional conformal radiotherapy (3DCRT, dynamic intensity modulated radiotherapy (D-IMRT, step-shoot (SS-IMRT, and volumetric modulated arc therapy (VMAT treatment delivery techniques due to intra- and inter-fractional target motion. Methods: A previously treated lung patient was selected for this study and was replanned for 60 Gy in 30 fractions using four techniques (3DCRT, D-IMRT, SS-IMRT, and VMAT. These plans were delivered in a clinical linear accelerator equipped with HexaPOD™ evo RT System. The target dose of static QUASAR phantom was calculated that served as reference dose to the target. The QUASAR respiratory body phantom along with patients breathing wave form and HexaPOD™ evo RT System was used to simulate the intra-fraction and inter-fraction motions. Dose measurements were done by applying the intra-fractional and inter-fractional motions in all the four treatment delivery techniques.Results: The maximum percentage deviation in a single field was -4.3%, 10.4%, and -12.2% for 3DCRT, D-IMRT and SS-IMRT deliveries, respectively. Similarly, the deviation for a single fraction was -1.51%, -1.88%, -2.22%, and -3.03% for 3DCRT, D-IMRT, SS-IMRT and VMAT deliveries, respectively. Conclusion: The impact of inter-fractional and intra-fractional uncertainties calculated as deviation between dynamic and static condition dose was large in some fractions, however average deviation calculated for thirty fractions was well within 0.5% in all the four techniques. Therefore, inter- and intra-fractional uncertainties could be concern in fewer fraction treatments such as stereotactic body radiation therapy, and should be used in conjunction with intra- and inter-fractional motion management techniques.

  9. Misonidazole in fractionated radiotherapy: are many small fractions best

    The largest sensitizing effect is always demonstrated with six fractions, each given with 2 g/m2 of misonidazole. In the absence of reoxygenation a sensitizer enhancement ratio of 1.7 is predicted, but this falls to 1.1-1.2 if extensive reoxygenation occurs. Less sensitization is observed with 30 fractions, each with 0.4 g/m2 of drug. However, for clinical use, the important question is which treatment kills the maximum number of tumour cells. Many of the simulations predict a marked disadvantage of reducing the fraction number for X rays alone. The circumstances in which this disadvantage is offset by the large Sensitizer enhancement ratio values with a six-fraction schedule are few. The model calculations suggest that many small fractions, each with a low drug dose, are safest unless the clinician has some prior knowledge that a change in fraction number is not disadvantageous. (author)

  10. Fractionated stereotactic radiotherapy in the treatment of pituitary adenomas

    Kopp, C.; Theodorou, M.; Poullos, N.; Astner, S.T.; Geinitz, H.; Molls, M. [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie; Stalla, G.K. [Max-Planck-Institut fuer Psychiatrie, Muenchen (Germany). Klinische Neuroendokrinologie; Meyer, B. [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Neurochirurgische Klinik und Poliklinik; Nieder, C. [Nordland Hospital, Bodoe (Norway). Dept. of Oncology and Palliative Medicine; Tromsoe Univ. (Norway). Inst. of Clinical Medicine; Grosu, A.L [Freiburg Univ. (Germany). Klinik fuer Strahlenheilkunde

    2013-11-15

    Purpose: The purpose of this work was to evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent pituitary adenomas. Patients and methods: We report on 37 consecutive patients with pituitary adenomas treated with FSRT at our department. All patients had previously undergone surgery. Twenty-nine patients had nonfunctioning, 8 had hormone-producing adenoma. The mean total dose delivered by a linear accelerator was 49.4 Gy (range 45-52.2 Gy), 5 x 1.8 Gy weekly. The mean PTV was 22.8 ccm (range 2.0-78.3 ccm). Evaluation included serial imaging tests, endocrinologic and ophthalmologic examination. Results: Tumor control was 91.9 % for a median follow-up time of 57 months (range 2-111 months). Before FSRT partial hypopituitarism was present in 41 % of patients, while 35 % had anterior panhypopituitarism. After FSRT pituitary function remained normal in 22 %, 43 % had partial pituitary dysfunction, and 35 % had anterior panhypopituitarism. Visual acuity was stable in 76 % of patients, improved in 19 %, and deteriorated in 5 %. Visual fields remained stable in 35 patients (95 %), improved in one and worsened in 1 patient (2.7 %). Conclusion: FSRT is an effective and safe treatment for recurrent or residual pituitary adenoma. Good local tumor control and preservation of adjacent structures can be reached, even for large tumors. (orig.)

  11. Fractionated stereotactic radiotherapy in the treatment of pituitary adenomas

    Purpose: The purpose of this work was to evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent pituitary adenomas. Patients and methods: We report on 37 consecutive patients with pituitary adenomas treated with FSRT at our department. All patients had previously undergone surgery. Twenty-nine patients had nonfunctioning, 8 had hormone-producing adenoma. The mean total dose delivered by a linear accelerator was 49.4 Gy (range 45-52.2 Gy), 5 x 1.8 Gy weekly. The mean PTV was 22.8 ccm (range 2.0-78.3 ccm). Evaluation included serial imaging tests, endocrinologic and ophthalmologic examination. Results: Tumor control was 91.9 % for a median follow-up time of 57 months (range 2-111 months). Before FSRT partial hypopituitarism was present in 41 % of patients, while 35 % had anterior panhypopituitarism. After FSRT pituitary function remained normal in 22 %, 43 % had partial pituitary dysfunction, and 35 % had anterior panhypopituitarism. Visual acuity was stable in 76 % of patients, improved in 19 %, and deteriorated in 5 %. Visual fields remained stable in 35 patients (95 %), improved in one and worsened in 1 patient (2.7 %). Conclusion: FSRT is an effective and safe treatment for recurrent or residual pituitary adenoma. Good local tumor control and preservation of adjacent structures can be reached, even for large tumors. (orig.)

  12. Radiobiological modeling of interplay between accelerated repopulation and altered fractionation schedules in head and neck cancer

    Marcu Loredana

    2009-01-01

    Full Text Available Head and neck cancer represents a challenge for radiation oncologists due to accelerated repopulation of cancer cells during treatment. This study aims to simulate, using Monte Carlo methods, the response of a virtual head and neck tumor to both conventional and altered fractionation schedules in radiotherapy when accelerated repopulation is considered. Although clinical trials are indispensable for evaluation of novel therapeutic techniques, they are time-consuming processes which involve many complex and variable factors for success. Models can overcome some of the limitations encountered by trials as they are able to simulate in less complex environment tumor cell kinetics and dynamics, interaction processes between cells and ionizing radiation and their outcome. Conventional, hyperfractionated and accelerated treatment schedules have been implemented in a previously developed tumor growth model which also incorporates tumor repopulation during treatment. This study focuses on the influence of three main treatment-related parameters, dose per fraction, inter fraction interval and length of treatment gap and gap timing based on RTOG trial data on head and neck cancer, on tumor control. The model has shown that conventionally fractionated radiotherapy is not able to eradicate the stem population of the tumor. Therefore, new techniques such as hyperfractionated/ accelerated radiotherapy schedules should be employed. Furthermore, the correct selection of schedule-related parameters (dose per fraction, time between fractions, treatment gap scheduling is crucial in overcoming accelerated repopulation. Modeling of treatment regimens and their input parameters can offer better understanding of the radiobiological interactions and also treatment outcome.

  13. Minimizing metastatic risk in radiotherapy fractionation schedules

    Badri, Hamidreza; Ramakrishnan, Jagdish; Leder, Kevin

    2015-11-01

    Metastasis is the process by which cells from a primary tumor disperse and form new tumors at distant anatomical locations. The treatment and prevention of metastatic cancer remains an extremely challenging problem. This work introduces a novel biologically motivated objective function to the radiation optimization community that takes into account metastatic risk instead of the status of the primary tumor. In this work, we consider the problem of developing fractionated irradiation schedules that minimize production of metastatic cancer cells while keeping normal tissue damage below an acceptable level. A dynamic programming framework is utilized to determine the optimal fractionation scheme. We evaluated our approach on a breast cancer case using the heart and the lung as organs-at-risk (OAR). For small tumor α /β values, hypo-fractionated schedules were optimal, which is consistent with standard models. However, for relatively larger α /β values, we found the type of schedule depended on various parameters such as the time when metastatic risk was evaluated, the α /β values of the OARs, and the normal tissue sparing factors. Interestingly, in contrast to standard models, hypo-fractionated and semi-hypo-fractionated schedules (large initial doses with doses tapering off with time) were suggested even with large tumor α/β values. Numerical results indicate the potential for significant reduction in metastatic risk.

  14. Minimizing metastatic risk in radiotherapy fractionation schedules.

    Badri, Hamidreza; Ramakrishnan, Jagdish; Leder, Kevin

    2015-11-21

    Metastasis is the process by which cells from a primary tumor disperse and form new tumors at distant anatomical locations. The treatment and prevention of metastatic cancer remains an extremely challenging problem. This work introduces a novel biologically motivated objective function to the radiation optimization community that takes into account metastatic risk instead of the status of the primary tumor. In this work, we consider the problem of developing fractionated irradiation schedules that minimize production of metastatic cancer cells while keeping normal tissue damage below an acceptable level. A dynamic programming framework is utilized to determine the optimal fractionation scheme. We evaluated our approach on a breast cancer case using the heart and the lung as organs-at-risk (OAR). For small tumor [Formula: see text] values, hypo-fractionated schedules were optimal, which is consistent with standard models. However, for relatively larger [Formula: see text] values, we found the type of schedule depended on various parameters such as the time when metastatic risk was evaluated, the [Formula: see text] values of the OARs, and the normal tissue sparing factors. Interestingly, in contrast to standard models, hypo-fractionated and semi-hypo-fractionated schedules (large initial doses with doses tapering off with time) were suggested even with large tumor α/β values. Numerical results indicate the potential for significant reduction in metastatic risk. PMID:26509743

  15. Influence of dose per fraction on 7 days per week fractionation in radiotherapy

    To evaluate the effect of the dose per fraction in a radiotherapy schedule of 7 fractions per week and compare it with a conventional one of 5fr/w, 2Gy/fr, we use computer simulations methods taking into account the tumor proliferation. We have a significant increase of TCP with regard to the conventional schedule for 7 days per week programmes in which the dose per fraction is =1.7 Gy. (author)

  16. Stereotactic Fractionated Radiotherapy in the Treatment of Juxtapapillary Choroidal Melanoma: The McGill University Experience

    Al-Wassia, Rolina; Dal Pra, Alan; Shun, Kitty; Shaban, Ahmed [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); Corriveau, Christine [Department of Ophthalmology, Notre Dame Hospital, Centre Hospitalier de l' Universite de Montreal, Montreal, Quebec (Canada); Edelstein, Chaim; Deschenes, Jean [Department of Ophthalmology, McGill University Health Centre, Montreal, Quebec (Canada); Ruo, Russel; Patrocinio, Horacio [Department of Medical Physics, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); Cury, Fabio L.B. [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); DeBlois, Francois [Department of Medical Physics, Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Shenouda, George, E-mail: george.shenouda@muhc.mcgill.ca [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada)

    2011-11-15

    Purpose: To report our experience with linear accelerator-based stereotactic fractionated radiotherapy in the treatment of juxtapapillary choroidal melanoma. Methods and Materials: We performed a retrospective review of 50 consecutive patients diagnosed with juxtapapillary choroidal melanoma and treated with linear accelerator-based stereotactic fractionated radiotherapy between April 2003 and December 2009. Patients with small to medium sized lesions (Collaborative Ocular Melanoma Study classification) located within 2 mm of the optic disc were included. The prescribed radiation dose was 60 Gy in 10 fractions. The primary endpoints included local control, enucleation-free survival, and complication rates. Results: The median follow-up was 29 months (range, 1-77 months). There were 31 males and 29 females, with a median age of 69 years (range, 30-92 years). Eighty-four percent of the patients had medium sized lesions, and 16% of patients had small sized lesions. There were four cases of local progression (8%) and three enucleations (6%). Actuarial local control rates at 2 and 5 years were 93% and 86%, respectively. Actuarial enucleation-free survival rates at 2 and 5 years were 94% and 84%, respectively. Actuarial complication rates at 2 and 5 years were 33% and 88%, respectively, for radiation-induced retinopathy; 9.3% and 46.9%, respectively, for dry eye; 12% and 53%, respectively, for cataract; 30% and 90%, respectively, for visual loss [Snellen acuity (decimal equivalent), <0.1]; 11% and 54%, respectively, for optic neuropathy; and 18% and 38%, respectively, for neovascular glaucoma. Conclusions: Linear accelerator-based stereotactic fractionated radiotherapy using 60 Gy in 10 fractions is safe and has an acceptable toxicity profile. It has been shown to be an effective noninvasive treatment for juxtapapillary choroidal melanomas.

  17. Stereotactic Fractionated Radiotherapy in the Treatment of Juxtapapillary Choroidal Melanoma: The McGill University Experience

    Purpose: To report our experience with linear accelerator-based stereotactic fractionated radiotherapy in the treatment of juxtapapillary choroidal melanoma. Methods and Materials: We performed a retrospective review of 50 consecutive patients diagnosed with juxtapapillary choroidal melanoma and treated with linear accelerator-based stereotactic fractionated radiotherapy between April 2003 and December 2009. Patients with small to medium sized lesions (Collaborative Ocular Melanoma Study classification) located within 2 mm of the optic disc were included. The prescribed radiation dose was 60 Gy in 10 fractions. The primary endpoints included local control, enucleation-free survival, and complication rates. Results: The median follow-up was 29 months (range, 1–77 months). There were 31 males and 29 females, with a median age of 69 years (range, 30–92 years). Eighty-four percent of the patients had medium sized lesions, and 16% of patients had small sized lesions. There were four cases of local progression (8%) and three enucleations (6%). Actuarial local control rates at 2 and 5 years were 93% and 86%, respectively. Actuarial enucleation-free survival rates at 2 and 5 years were 94% and 84%, respectively. Actuarial complication rates at 2 and 5 years were 33% and 88%, respectively, for radiation-induced retinopathy; 9.3% and 46.9%, respectively, for dry eye; 12% and 53%, respectively, for cataract; 30% and 90%, respectively, for visual loss [Snellen acuity (decimal equivalent), <0.1]; 11% and 54%, respectively, for optic neuropathy; and 18% and 38%, respectively, for neovascular glaucoma. Conclusions: Linear accelerator-based stereotactic fractionated radiotherapy using 60 Gy in 10 fractions is safe and has an acceptable toxicity profile. It has been shown to be an effective noninvasive treatment for juxtapapillary choroidal melanomas.

  18. Prospective Trial of Accelerated Partial Breast Intensity-Modulated Radiotherapy

    Purpose: To examine the feasibility and acute toxicities of an accelerated, partial breast, intensity-modulated radiotherapy (IMRT) protocol. Methods and Materials: Between February 2004 and August 2005, 55 patients with Stage I breast cancer and initial follow-up were enrolled at four facilities on a HealthONE and Western institutional review board-approved accelerated partial breast IMRT protocol. All patients were treated in 10 equal fractions delivered twice daily within 5 consecutive days. The first 7 patients were treated to 34 Gy, and the remaining 48 patients were treated to 38.5 Gy. Results: The median follow-up after IMRT was 10 months (range, <1-19) and after diagnosis was 11.5 months (range, 2-21). No local or distant recurrences developed. The T stage distribution was as follows: T1a in 11 patients, T1b in 24, and T1c in 20. The median tumor size was 9 mm (range, 1-20 mm). Breast cosmesis was judged by the patient as poor by 2, good by 12, and excellent by 40 (1 patient was legally blind) and by the physician as poor for 1, good for 10, and excellent for 44 patients. Breast pain, as judged by patient, was none in 34, mild in 19, moderate in 2, and severe in 0 patients. There was a single report of telangiectasia but no incidents of significant edema. Compared with historic controls for whom three-dimensional treatment planning techniques were used, IMRT provided similar dose delivery to the target while reducing the volume of normal breast included in the 100%, 75%, and 50% isodose lines. Conclusion: This initial report prospectively explored the feasibility of accelerated partial breast IMRT. After short-term follow-up, the dose delivery and clinical outcomes were very acceptable. We believe this regimen deserves additional investigation under institutional review board guidance

  19. SU-E-J-105: Stromal-Epithelial Responses to Fractionated Radiotherapy

    Qayyum, M [Little Company of Mary Hospital, Ever Green Park, IL (United States)

    2014-06-01

    Purpose: The stromal-epithelial-cell interactions that are responsible for directing normal breast-tissue development and maintenance play a central role in the progression of breast cancer. In the present study, we developed three-dimensional (3-D) cell co-cultures used to study cancerous mammary cell responses to fractionated radiotherapy. In particular, we focused on the role of the reactive stroma in determining the therapeutic ratio for postsurgical treatment. Methods: Cancerous human mammary epithelial cells were cultured in a 3-D collagen matrix with human fibroblasts stimulated by various concentrations of transforming growth factor beta 1 (TGF-β1). These culture samples were designed to model the post-lumpectomy mammary stroma in the presence of residual cancer cells. We tracked over time the changes in medium stiffness, fibroblast-cell activation (conversion to cancer activated fibroblasts (CAF)), and proliferation of both cell types under a variety of fractionated radiotherapy protocols. Samples were exposed to 6 MV X-rays from a linear accelerator in daily fraction sizes of 90, 180 and 360 cGy over five days in a manner consistent with irradiation exposure during radiotherapy. Results: We found in fractionation studies with fibroblasts and CAF that higher doses per fraction may be more effective early on in deactivating cancer-harboring cellular environments. Higher-dose fraction schemes inhibit contractility in CAF and prevent differentiation of fibroblasts, thereby metabolically uncoupling tumor cells from their surrounding stroma. Yet, over a longer time period, the higher dose fractions may slow wound healing and increase ECM stiffening that could stimulate proliferation of surviving cancer cells. Conclusion: The findings suggest that dose escalation to the region with residual disease can deactivate the reactive stroma, thus minimizing the cancer promoting features of the cellular environment. Large-fraction irradiation may be used to sterilize

  20. Measurement of reoxygenation during fractionated radiotherapy in head and neck squamous cell carcinoma xenografts

    Full text: Hypoxic tissues lack adequate oxygenation and it has been long established that tumours commonly exhibit hypoxia and that hypoxia is a factor contributing towards resistance to radiotherapy. To develop computer models and make predictions about the affects of tumour hypoxia on treatment outcome, quantitative tumour oxygenation and reoxygenation data from in vivo systems is required. The aim of this study was to investigate the timing and degree of reoxygenation during radiotherapy in a human head and neck squamous cell carcinoma xenograft mouse model (FaDu). Mice were immobilised using a novel restraining system and exposed unanaesthetised in 3 or 5 Gy fractions, up to a maximum of 40 Gy. Partial pres sures of oxygen (p02) measurements were recorded at six time points throughout the 2 week course of radiotherapy, using a fibre optic system. Tumours receiving 0-30 Gy did not exhibit an increase in p02' However, the mean p02 after 2 weeks of accelerated fractionated radiotherapy (40 Gy) was significantly increased (P < 0.01) compared

  1. Quality assurance protocol for linear accelerators used in radiotherapy

    Radiotherapy is a modality of choice for treatment of malignant diseases. Linear accelerators are the most common devices for implementing external radiation therapy. Taking into account the fact during the treatment, healthy tissue will inevitably be exposed to ionizing radiation, predicted dose in each radiotherapy case should be delivered with the greatest possible accuracy. Medical requirement for quality treatment achieving means as mach as possible dose into volume of interest and the greatest possible healthy tissue protection. From radiation protection point of view, occupational exposure of the staff involved in radiotherapy process should be minimized. To be able to reach it, consistent adherence to the Quality Assurance Programme is necessary. It should be in accordance with higher national and international protocols, because they give guidelines on the necessary standards, procedures, processes, resources and responsibilities that should be defined in structuring the overall radiotherapy quality management. As a part of this Master thesis, quality management as well as Quality Assurance Programme that is necessary to be applied in each radiotherapy center have been prepared. Mandatory dosimetry measurements included in the internal recommendations are also emphasized. Measurement results and external audit by IAEA indicated high accuracy and quality radiotherapy dose delivering in Macedonia. Based on the measurements and analysis, the aim of this Master thesis is offering a Quality Assurance Protocol for external beam radiotherapy that can be used on the national level in Republic of Macedonia. (Author)

  2. Radiotherapy using a laser proton accelerator

    Murakami, Masao; Miyajima, Satoshi; Okazaki, Yoshiko; Sutherland, Kenneth L; Abe, Mitsuyuki; Bulanov, Sergei V; Daido, Hiroyuki; Esirkepov, Timur Zh; Koga, James; Yamagiwa, Mitsuru; Tajima, Toshiki

    2008-01-01

    Laser acceleration promises innovation in particle beam therapy of cancer where an ultra-compact accelerator system for cancer beam therapy can become affordable to a broad range of patients. This is not feasible without the introduction of a technology that is radically different from the conventional accelerator-based approach. The laser acceleration method provides many enhanced capabilities for the radiation oncologist. It reduces the overall system size and weight by more than one order of magnitude. The characteristics of the particle beams (protons) make them suitable for a class of therapy that might not be possible with the conventional accelerator, such as the ease for changing pulse intensity, the focus spread, the pinpointedness, and the dose delivery in general. A compact, uncluttered system allows a PET device to be located in the vicinity of the patient in concert with the compact gantry. The radiation oncologist may be able to irradiate a localized tumor by scanning with a pencil-like particle...

  3. Fractionated stereotactic radiotherapy of brain metastases from renal cell carcinoma

    Purpose: To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for brain metastases from renal cell carcinoma (RCC). Methods and Materials: From May 1983 to September 1998, 35 patients with brain metastases from RCC underwent radiotherapy at the National Cancer Center Hospital, Tokyo; 10 patients treated initially with FSRT (FSRT group); 11 with surgery followed by conventional radiotherapy (S/CR group); and 14 with conventional radiotherapy (CR group). Survival and local control rates were determined for patients who had an ECOG performance status of 0-2. Results: Overall median survival rate was 18 months, and actuarial 1- and 2-year survival rates were 57.6% and 31.0%, respectively. Median survival rates were 25.6 months for the FSRT group, 18.7 months for the S/CR group, and 4.3 months for the CR group. Significant prognostic factors associated with survival were age less than 60 years and good performance status. In patients treated with FSRT, imaging studies revealed that 21 of 24 tumors (88%) were locally controlled during a median follow-up time of 5.2 months (range 0.5-68). Actuarial 1- and 2-year local control rates were 89.6% and 55.2%, respectively. No patient suffered from acute or late complications during and following FSRT. Conclusions: FSRT offers better tumor control and prolonged survival over the S/CR or CR groups, and should be considered as primary treatment for brain metastases from RCC. Patients under 60-years-old and those with a good performance status at the beginning of radiotherapy had a better prognosis.

  4. Fractionated radiotherapy of intracranial meningiomas and neurinomas; Radiotherapie fractionnee des meningiomes et des neurinomes intracraniens

    Maire, J.P.; Vendrely, V.; Bonichon, N. [Hopital Saint-Andre, Service d' oncologie-Radiotherapie, 33 - Bordeaux (France); Dautheribes, M. [Hopital Saint-Andre, Service de Neurochirurgie, 33 - Bordeaux (France); Darrouzet, V. [Hopital Saint-Andre, Service d' Otorhinoloryngologie, 33 - Bordeaux (France)

    2000-12-01

    In lost institutions, surgical excision remains the standard treatment of meningiomas and neurinomas; the aim of surgery is complete resection. However, total removal is not always feasible without significant morbidity and in some cases, the patient's condition contraindicates surgery. For incompletely excised tumors, recurrences will have consequences on neurological functions. There are now many reports in the literature confirming the fact that radiotherapy significantly decreases the incidence of recurrence of incompletely resected benign tumors and that it can replace surgery in some situations where an operation would involve considerable danger or permanent neurological damage: about 80 to 90% of such tumors are controlled with fractionated radiotherapy. Stereotaxic and three-dimensional treatment planning techniques increase local control and central nervous system tolerance so that the respective place of surgery and radiotherapy needs to be redefined, considering efficacy and morbidity of these two therapeutic means. In this article, we limit our remarks to fractionated radiotherapy and, after a review of the literature, we discuss the indications, volume evaluations and the techniques currently used. (authors)

  5. Preliminary results of fractionated stereotactic radiotherapy for benign brain tumors

    Choi, Byung Ock [College of Medicine, Catholic Univ., Seoul (Korea, Republic of); Kang, Ki Mun [Cellege of Medicine, Gyeongsang National Univ., Jinju, (Korea, Republic of)

    2003-03-01

    To evaluate the role of fractionated stereotactic radiotherapy (FSRT) in the management of benign brain tumors, we reviewed the clinical, and radiographic responses of patients treated. Between March 1996 and March 2002, 36 patients with benign brain tumors were treated by FSRT. The pathological diagnoses consisted of pituitary adenomas (12 patients), craniopharyngiomas (5 patients), meningiomas (10 patients), and acoustic neurinomas (9 patients). Radiotherapy doses of 25 to 35 Gy (3-6 Gy/fraction, 5-10 fractions) were prescribed to the 85-90% isodose line, depending upon the location, size and volume of the tumors. The median clinical and radiographical followup periods were 31 [range, 2-74) and 21 (range, 4-56) months, respectively. In the 35 patients that could be evaluated for their clinical response, 13 (37.1%) were considered improved, 16 (45.7%) stable and 6 (17.2%) worse. Of the 33 patients who had radiographic studies, tumor shrinkage was noted in 17 (51.5%), tumor stabilization in 13 (39.4%), and tumor progression in 3 (9,1%). Of the 17 tumor shrinkage patients, 7 [21.2%) showed a complete response, Acute radiation-induced complications occurred in 11 (30.6%) patients. FSRT is considered a safe and effective treatment method for benign brain tumors but large numbers of patients, with relatively long follow-up periods are needed to assess the exact role or effect of FSRT.

  6. Fractionated Proton Radiotherapy for Benign Cavernous Sinus Meningiomas

    Slater, Jerry D., E-mail: jdslater@dominion.llumc.edu [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, CA (United States); Loredo, Lilia N.; Chung, Arthur; Bush, David A.; Patyal, Baldev [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, CA (United States); Johnson, Walter D.; Hsu, Frank P.K. [Department of Neurosurgery, Loma Linda University Medical Center, Loma Linda, CA (United States); Slater, James M. [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, CA (United States)

    2012-08-01

    Purpose: To evaluate the efficacy of fractionated proton radiotherapy for a population of patients with benign cavernous sinus meningiomas. Methods and Materials: Between 1991 and 2002, 72 patients were treated at Loma Linda University Medical Center with proton therapy for cavernous sinus meningiomas. Fifty-one patients had biopsy or subtotal resection; 47 had World Health Organization grade 1 pathology. Twenty-one patients had no histologic verification. Twenty-two patients received primary proton therapy; 30 had 1 previous surgery; 20 had more than 1 surgery. The mean gross tumor volume was 27.6 cm{sup 3}; mean clinical target volume was 52.9 cm{sup 3}. Median total doses for patients with and without histologic verification were 59 and 57 Gy, respectively. Mean and median follow-up periods were 74 months. Results: The overall 5-year actuarial control rate was 96%; the control rate was 99% in patients with grade 1 or absent histologic findings and 50% for those with atypical histology. All 21 patients who did not have histologic verification and 46 of 47 patients with histologic confirmation of grade 1 tumor demonstrated disease control at 5 years. Control rates for patients without previous surgery, 1 surgery, and 2 or more surgeries were 95%, 96%, and 95%, respectively. Conclusions: Fractionated proton radiotherapy for grade 1 cavernous sinus meningiomas achieves excellent control rates with minimal toxicities, regardless of surgical intervention or use of histologic diagnosis. Disease control for large lesions can be achieved by primary fractionated proton therapy.

  7. Response of human hair cortical cells to fractionated radiotherapy

    Hair cortical cell counting (HCCC) represents a non-invasive, in-vivo measure of cell kill in the human integument. Sixty-six patients undergoing conventionally fractionated, external beam radiotherapy for early stage carcinoma of the prostate had groin hair samples counted. This technique is a sensitive and reproducible measure of radiation effect and may have applicability as an in-vivo prediction tool or in the field of biological dosimetry. A repopulative follicular response occurring at 3-4 weeks may explain flattening of the dose response curve

  8. Comparison between continuous accelerated hyperfractionated and late-course accelerated hyperfractionated radiotherapy for esophageal carcinoma

    Purpose: To compare the treatment results and toxicity of continuous accelerated hyperfractionated (CAHF) and late-course accelerated hyperfractionated (LCAF) radiotherapy (RT) for esophageal carcinoma. Methods and Materials: Between August 1996 and March 1999, 101 patients with squamous cell carcinoma of the esophagus were randomized into two groups: 49 to the CAHF group and 52 to the LCAF group. Patients in the CAHF group received RT at 1.5 Gy/fraction b.i.d. (6-h interval), 5 d/wk, to a total dose 66 Gy in 44 fractions during 4.4 weeks. The patients in the LCAF group received conventional fractionation RT, 1.8 Gy/fraction, to a dose of 41.4 Gy in 23 fractions during 4.6 weeks, followed by accelerated fractionation RT using reduced fields, b.i.d., at 1.5 Gy/fraction, with a minimal interval of 6 h between fractions. The total dose was 68.4 Gy in 41 fraction during 6.4 weeks. Patient age, gender, performance score, diet, lesion location, lesion length, stage, and fractionation (CAHF or LCAF) were entered into the univariate and multivariate analyses. Results: All patients finished the treatment course, except for 1 patient in the CAHF group because of severe acute esophagitis. The rate of Grade I, II, and III acute bronchitis was 18.4% (9 of 49), 30.6% (15 of 49), and 8.2% (4 of 49) in the CAHF group and 13.5% (7 of 52), 21.2% (11 of 52), and 3.8% (2 of 52) in the LCAF group, respectively. However, the difference between the two groups was not statistically significant (p=0.084). The rate of Grade I, II, III, and IV acute esophagitis was 6.1% (3 of 49), 32.7% (16 of 49), 46.9% (23 of 49), and 14.3% (7 of 49) in the CAHF group and 26.9% (14 of 52), 32.7% (17 of 52), 7.7% (4 of 52), and 1.9% (1 of 52) in the LCAF group, respectively. The difference was statistically significant (p<0.001). The local control rate at 1, 2, and 3 years was 88.7%, 83.9%, and 55.9% in the CAHF group and 80.7%, 71.4%, and 57.1% in the LCAF group, respectively (p=0.1251). The 1-, 2-, and 3

  9. Optimal fractionation in radiotherapy with multiple normal tissues.

    Saberian, Fatemeh; Ghate, Archis; Kim, Minsun

    2016-06-01

    The goal in radiotherapy is to maximize the biological effect (BE) of radiation on the tumour while limiting its toxic effects on healthy anatomies. Treatment is administered over several sessions to give the normal tissue time to recover as it has better damage-repair capabilities than tumour cells. This is termed fractionation. A key problem in radiotherapy involves finding an optimal number of treatment sessions (fractions) and the corresponding dosing schedule. A major limitation of existing mathematically rigorous work on this problem is that it includes only a single normal tissue. Since essentially no anatomical region of interest includes only one normal tissue, these models may incorrectly identify the optimal number of fractions and the corresponding dosing schedule. We present a formulation of the optimal fractionation problem that includes multiple normal tissues. Our model can tackle any combination of maximum dose, mean dose and dose-volume type constraints for serial and parallel normal tissues as this is characteristic of most treatment protocols. We also allow for a spatially heterogeneous dose distribution within each normal tissue. Furthermore, we do not a priori assume that the doses are invariant across fractions. Finally, our model uses a spatially optimized treatment plan as input and hence can be seamlessly combined with any treatment planning system. Our formulation is a mixed-integer, non-convex, quadratically constrained quadratic programming problem. In order to simplify this computationally challenging problem without loss of optimality, we establish sufficient conditions under which equal-dosage or single-dosage fractionation is optimal. Based on the prevalent estimates of tumour and normal tissue model parameters, these conditions are expected to hold in many types of commonly studied tumours, such as those similar to head-and-neck and prostate cancers. This motivates a simple reformulation of our problem that leads to a closed

  10. Quantifying intra- and inter-fractional motion in breast radiotherapy

    Jones, Scott, E-mail: scott.jones@health.qld.gov.au [Division of Cancer Services, Radiation Oncology Mater Centre, Princess Alexandra Hospital, Brisbane (Australia); Fitzgerald, Rhys [Division of Cancer Services, Princess Alexandra Hospital, Brisbane (Australia); Owen, Rebecca; Ramsay, Jonathan [Division of Cancer Services, Radiation Oncology Mater Centre, Princess Alexandra Hospital, Brisbane (Australia)

    2015-03-15

    The magnitude of intra- and inter-fractional variation in the set up of breast cancer patients treated with tangential megavoltage photon beams was investigated using an electronic portal imaging device (EPID). Daily cine-EPID images were captured during delivery of the tangential fields for ten breast cancer patients treated in the supine position. Measurements collected from each image included the central lung distance (CLD), central flash distance (CFD), superior axial measurement (SAM) and the inferior axial measurement (IAM). The variation of motion within a fraction (intra-fraction) and the variation between fractions (inter-fraction) was analysed to quantify set up variation and motion due to respiration. Altogether 3775 EPID images were collected from 10 patients. The effect of respiratory motion during treatment was <0.1 cm standard deviation (SD) in the anterior–posterior (AP) direction. The inter-fraction movement caused by variations in daily set up was larger at 0.28 cm SD in the AP direction. Superior–inferior (SI) variation was more difficult to summarise and proved unreliable as the measurements were taken to an ambiguous point on the images. It was difficult to discern true SI movement from that implicated by AP movement. There is minimal intra-fractional chest wall motion due to respiration during treatment. Inter-fractional variation was larger, however, on average it remained within departmental tolerance (0.5 cm) for set up variations. This review of our current breast technique provides confidence in the feasibility of utilising advanced treatment techniques (field-in-field, intensity modulated radiotherapy or volumetric modulated arc therapy) following a review of the current imaging protocol.

  11. Quantifying intra- and inter-fractional motion in breast radiotherapy

    The magnitude of intra- and inter-fractional variation in the set up of breast cancer patients treated with tangential megavoltage photon beams was investigated using an electronic portal imaging device (EPID). Daily cine-EPID images were captured during delivery of the tangential fields for ten breast cancer patients treated in the supine position. Measurements collected from each image included the central lung distance (CLD), central flash distance (CFD), superior axial measurement (SAM) and the inferior axial measurement (IAM). The variation of motion within a fraction (intra-fraction) and the variation between fractions (inter-fraction) was analysed to quantify set up variation and motion due to respiration. Altogether 3775 EPID images were collected from 10 patients. The effect of respiratory motion during treatment was <0.1 cm standard deviation (SD) in the anterior–posterior (AP) direction. The inter-fraction movement caused by variations in daily set up was larger at 0.28 cm SD in the AP direction. Superior–inferior (SI) variation was more difficult to summarise and proved unreliable as the measurements were taken to an ambiguous point on the images. It was difficult to discern true SI movement from that implicated by AP movement. There is minimal intra-fractional chest wall motion due to respiration during treatment. Inter-fractional variation was larger, however, on average it remained within departmental tolerance (0.5 cm) for set up variations. This review of our current breast technique provides confidence in the feasibility of utilising advanced treatment techniques (field-in-field, intensity modulated radiotherapy or volumetric modulated arc therapy) following a review of the current imaging protocol

  12. Study of different dose fractionation in radiotherapy of larynx carcinoma

    In a clinical study the efficacy of a new fractionation scheme of radiotherapy of the carcinoma of the larynx was investigated. Radiation was applied every second day, three times a week, dose fractions being 4 Gy or 3.5 Gy, tumour doses 52 Gy, 52.5 Gy or 56 Gy. The results in 95 patients who were managed using this radiation scheme were compared with those in 129 patients, where the tumour dose, conventionally fractionated, was 60 Gy, 66 Gy or 70 Gy. The results in primarily cured patients, irrespective of the site and the stage of the tumour, were significantly better (p<0.05) with the new fractionation scheme. Statistically significant improvement of primary healing was proved in supraglottal carcinoma of the Ist and IInd stage and in the Ist and IIIrd stage of glottal carcinoma. In the new fractionation scheme higher occurrence of stronger reaction of the mucous membrane and of late radiation edema was found; complications of a more serious nature did not occur. (author)

  13. Fractionated stereotactic radiotherapy with vagina carotica protection technique for local residual nasopharyngeal carcinoma after primary radiotherapy

    LIU Feng; HUAN Fu-kui; FANG Hao; WAN Bao; LI Ye-xiong; XIAO Jian-ping; XU Ying-jie; ZHANG Ye; XU Guo-zhen; GAO Li; YI Jun-lin; LUO Jing-wei; HUANG Xiao-dong

    2012-01-01

    Background Local failure of nasopharyngeal carcinoma (NPC) after radiotherapy (RT) remains one of the major treatment failures.This study aimed to evaluate the clinical efficacy and complications of fractionated stereotactic radiotherapy (FSRT) with vagina carotica protection technique for local residual of NPC patients after the primary RT.Methods From August 2006 to August 2010,FSRT with vagina carotica protection technique was applied to 36 patients in our department,the patients aged between 13 and 76 years with a median of 41.3 years,25 of them were male and 11were female.According to 2002 Union for International Cancer Control (UICC) Staging System,the stages before primary radiotherapy were:Ⅱa 2,Ⅱb 5,Ⅲ 18,Ⅳa 7,Ⅳb 4.In the first course of radiotherapy,9 patients received conventional RT,27 patients received intensity modulated radiotherapy (IMRT) and 20 out of the 36 patients received concurrent chemoradiotherapy.The total dose in the first course of RT was 69.96-76.90 Gy (median,72.58 Gy).The intervals between the primary RT and FSRT ranged from 12 to 147 days (median,39.8 days).Target volumes ranged from 1.46 to 32.98 cm3 (median,14.94 cm3).The total FSRT doses were 10.0-24.0 Gy (median,16.5 Gy) with 2.0-5.0Gy per fraction.The most common regimen was 15 Gy in 5 fractions of 3 Gy,the irradiation dose to vagina carotica was less than 2 Gy per fraction.Results The median follow-up time was 34 months (range,12-59 months).The 3-year local control rate was 100%;the 3-year overall survival rate was 94.4%;the 3-year disease-free survival rate was 77.8%.In this study,we had one case of cranial nerve injury,two cases of temporal lobe necrosis,and no nasopharyngeal massive hemorrhage was observed.Conclusion FSRT with vagina carotica protection technique is an effective and safe RT regimen for local residual of NPC with reduction of radiation-related neurovascular lesions.

  14. Metastatic spinal cord compression: radiotherapy outcome and dose fractionation

    Background and purpose: No standard dose fractionation has been defined for metastatic spinal cord compression. This retrospective analysis was undertaken to explore the impact of hypo fractionated treatment compared to conventional multi fraction treatment. Materials and methods: One hundred and two consecutive patients referred to Mount Vernon Cancer Centre with metastatic spinal canal compression confirmed on MR scan in 95% with median age 68 years (range 32-90) and main primary tumour types breast (28%), prostate (28%) and lung (20%); 51% of patients were fully ambulant at diagnosis, 41% ambulant but with paraparesis and 9% had complete paraplegia. Spinal radiotherapy was given delivering a single dose in 32% and 20 Gy in five fractions in 64%. Results: The median survival was 3.5 months; survival was significantly related to primary site and motor function at presentation. Normal ambulation was achieved in 58% at 2 weeks and 71% up to 2 months after treatment. No patient who presented with paraplegia regained function. At presentation 59% of patients had severe pain, which fell to 8% at 2 weeks. Comparing those patients who received one or two dose treatments with those who received protracted fractionation, the two groups were matched for age, sex, primary site and site of compression. Relatively more patients treated with one or two doses had paraplegia; 19% vs. 3%. Despite this outcome in the two groups was equivalent for motor and sphincter function and pain control. Conclusions: Metastatic spinal canal compression carries a poor prognosis. Urgent treatment will maintain and improve motor function in patients presenting ambulant but those who have paraplegia at presentation do not improve and have a very short survival. In this series no difference in outcome was seen between patients treated with one or two radiation doses compared to multi fraction treatment; a randomised trial comparing fractionation schedules would be justified

  15. Accelerated hyperfractionated radiotherapy for locally advanced cervix cancer

    Purpose: A phase II trial was designed to evaluate the toxicity and outcome of patients with locally advanced cervix cancer treated with accelerated hyperfractionated radiotherapy (AHFX). Methods and Materials: In this prospective trial, AHFX doses of 1.25 Gy were administered twice daily at least 6 hours apart to a total pelvic dose of 57.5 Gy. A booster dose was then administered via either low-dose rate brachytherapy or external beam therapy to a smaller volume. All patients were accrued and treated at Peter MacCallum Cancer Institute (PMCI) between 1986 until April 1991. Results: Sixty-one eligible patients were enrolled in this protocol; 2 (3.2%) had Stage IIB; 42 (68.9%) had Stage III; 8 (13.1%) had Stage IV and 9 (14.8%) had recurrent cervical cancer. Fifty-two patients (85%) completed the planned external beam without a treatment break. Thirty patients had acute toxicity that required regular medication. One patient died of acute treatment related toxicity. Fifty-five patients received booster therapy: 45 with intrauterine brachytherapy, 6 with interstitial brachytherapy, and 4 with external beam. The median follow-up of surviving patients was 6 years. Overall 5-year survival is 27% and 5-year relapse free survival is 36%. Nineteen patients died with pelvic disease and the actuarial local control rate was 66%. There were 8 severe late complications observed in 7 patients. Seven required surgical intervention (an actuarial rate of 27%). Five patients also required total hip replacement. Conclusions: The local control rate was favorable compared with other series that have used standard fractionation, although overall survival remained similar. The severe late complication rate was high for this protocol and higher than similar protocols reported in the literature

  16. Improved immobilization and verification of fractionated stereotactic radiotherapy

    Accepted radiobiological principles predict improved results in terms of late effects, when treatment is fractionated. With the advent of reliable relocatable stereotactic frames, fractionated stereotactic radiotherapy is becoming a standard tool in the treatment of brain malignancies. At the Ottawa Regional Cancer Centre we have developed a system for the delivery of fractionated stereotactic radiotherapy with the following unique features: 1) Very accurate, stable, reproducible, non-invasive BRW-compatible relocatable stereotactic frame, based on a custom made Cobalt-Chrome bite block with circumferential clasps that lock into the undercuts of the teeth. This design results in precise repositioning and virtually eliminates translational and rotational head motion. 2) Positional verification which consists of the following: a) CT verification: Following treatment planning the calculated Cartesian coordinates of the target centre are marked on the localizer frame with 0.5mm Pb shot. A CT slice is then obtained through the plane defined by the lead shots to verify the centre of the target volume. The lines connecting the opposed lead shots should intersect at the calculated isocentre. b) Check film: Patient setup is verified using 3 mm Pb shot placed on the patient's skin at each of the lateral laser crosses as well as the anterior laser cross. AP and lateral double exposure check films are then taken. The projected distances between the Pb shot at the isocentre (centre of the circular field) and the other Pb shot on the patient skin is measured and compared to the corresponding distances on the treatment plan and on the verification CT. c) PPMS: Our optically based Patient Position Monitoring system (PPM) is used to measure setup and treatment error. Measurements of patient and frame position are made in 3D with a resolution of better than 0.2 mm and accuracy of better than 0.4 mm. PPM is used to assist and verify setup and to record treatment position every 5

  17. Neutronic fields produced by a lineal accelerator for radiotherapy

    Measurements and Monte Carlo calculations has been utilized to determine the dosimetric features as well as the neutron spectra of photoneutrons produced around an 18 MV linear accelerator for radiotherapy. Measurements were carried out with bare and Cd covered thermoluminescent dosimeters, TLD600 and TLD700, as well as inside a paraffine moderator. TLD pairs were also utilized as thermal neutrons inside a Bonner sphere spectrometer (au)

  18. Dosimetric effect of intra-fractional and inter-fractional target motion in lung cancer radiotherapy techniques

    Teerthraj Verma; Nirmal Painuly; Surendra Mishra; SA Yoganathansa; Gourav Jain; Ankit Srivastava; Navin Singh; MLB Bhatt; Naseem Jamal; MC Pant

    2015-01-01

    Purpose: The purpose of present study was to experimentally evaluate the dosimetric uncertainties in 3-dimensional conformal radiotherapy (3DCRT), dynamic intensity modulated radiotherapy (D-IMRT), step-shoot (SS-IMRT), and volumetric modulated arc therapy (VMAT) treatment delivery techniques due to intra- and inter-fractional target motion. Methods: A previously treated lung patient was selected for this study and was replanned for 60 Gy in 30 fractions using four techniques (3DCRT, D-IMRT, ...

  19. Late course accelerated hyperfractionated radiotherapy for clinical T1-2 esophageal carcinoma

    Kuai-Le Zhao; Yang Wang; Xue-Hui Shi

    2003-01-01

    AIM: This retrospective study was designed to analyze the results and the failure patterns of late course accelerated hyperfractionated radiotherapy for clinical T1-2NoMo esophageal carcinoma. METHODS: From Aug. 1994 to Feb. 2001, 56 patients with clinical T1-2 esophageal carcinoma received late course accelerated hyperfractionated radiotherapy in Cancer Hospital,Fudan University. All patients had been histologically proven to have squamous cell carcinoma (SCC) and were diagnosed to be T1-2NoMo by CT scan. All patients were treated with conventional fractionation (CF) irradiation during the first twothirds course of the treatment to a dose of about 41.4Gy/23fx/4 to 5 weeks, Which was then followed by accelerated hyperfractionation irradiation using reduced fields, twice daily at 1.SGy per fraction, to a dose about 27Gy/18 fx. Thus the total dose was 67-70Gy/40-43fx/40-49 d. RESULTS: The 1-, 3- and 5-year overall survival was 90.9 %,54.6 %, 47.8 % respectively. The 1-, 3- and 5-year local control rate was 90.9 %, 84.5 % and 84.5 %, respectively.Twenty-five percent (14/56) patients had distant metastasis and/or lymph nodes metastasis alone. Eight point nine percent (5/56) patients had local disease alone. Another 3.6 % (2/56) patients had regional relapse and distant metastasis. CONCLUSION: Late course accelerated hyperfractionated radiotherapy is effective on clinical T1-2 esophageal carcinoma.The main failure pattern is distant metastasis.

  20. Stereotactic fractionated radiotherapy in patients with optic nerve sheath meningioma

    Purpose: To evaluate the effectiveness of stereotactic fractionated radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). Methods and Materials: Between 1994 and 2000, a total of 39 patients with either primary (n=15) or secondary (n=24) ONSM were treated with SFRT and received a median total tumor dose of 54 Gy using 1.8 Gy/fraction. Results: The radiographic response to SFRT was documented in all patients as stable disease (no change) except for 1 patient with a partial response. After a median follow-up of 35.5 months, all patients with ONSM were alive without recurrence. The visual fields and visual acuity were improved in 6 of 15 and 1 of 16 examined eyes in patients with primary ONSM, respectively, and in 6 of 24 and 7 of 26 examined eyes in patients with secondary ONSM, respectively. Stable visual fields and visual acuity was observed in 8 of 14 and 15 of 16 patients with primary ONSM, respectively, and in 17 of 24 and 19 of 26 patients with secondary ONSM, respectively. Except for reversible alopecia and erythema, no other SFRT-related toxicity was observed. Conclusion: SFRT represents a very effective and low-toxic treatment modality for ONSM. Despite a median follow-up of 3 years, this series of primary ONSM holds promise for future studies. It adds substantial evidence that SFRT may definitely become a standard treatment approach in selected cases of ONSM

  1. Research on relationship between dose per fraction and therapeutic effect in fractionated radiotherapy with a tumor control probability model

    Objective: To study whether the effect can be improved by using unequal dose per fraction in fractionated radiotherapy with the given overall treatment dose and time. Methods: Referring to the calculating formula of cell surviving probability, a new tumor control probability (TCP) calculating model following the fractionated radiotherapy has been set up. Then with four assumed fractionated dose protocols (fractionated dose increase or decrease in a week or in the whole treatment time), the TCP value will be calculated with the calculation model to get the relationship curves of some interested variables. Results: The calculation results show that the four assumed unequal fractionated dose (UEFD) protocols were better than the conventional equal fractionated dose (EFD) protocol. The more uneven fractionated dose distribution was the better TCP results would be. Conclusion: Given the overall treatment dose and time, treatment with UFED protocols can get better therapeutic effect than treatment with EFD protocol theoretically

  2. Fractionated stereotactic conformal radiotherapy for large benign skull base meningiomas

    to assess the safety and efficacy of fractionated stereotactic radiotherapy (FSRT) for large skull base meningiomas. Fifty-two patients with large skull base meningiomas aged 34-74 years (median age 56 years) were treated with FSRT between June 2004 and August 2009. All patients received FSRT for residual or progressive meningiomas more than 4 centimeters in greatest dimension. The median GTV was 35.4 cm3 (range 24.1-94.9 cm3), and the median PTV was 47.6 cm3 (range 33.5-142.7 cm3). Treatment volumes were achieved with 5-8 noncoplanar beams shaped using a micromultileaf collimator (MLC). Treatment was delivered in 30 daily fractions over 6 weeks to a total dose of 50 Gy using 6 MV photons. Outcome was assessed prospectively. At a median follow-up of 42 months (range 9-72 months) the 3-year and 5-year progression-free survival (PFS) rates were 96% and 93%, respectively, and survival was 100%. Three patients required further debulking surgery for progressive disease. Hypopituitarism was the most commonly reported late complication, with a new hormone pituitary deficit occurring in 10 (19%) of patients. Clinically significant late neurological toxicity was observed in 3 (5.5%) patients consisting of worsening of pre-existing cranial deficits. FSRT as a high-precision technique of localized RT is suitable for the treatment of large skull base meningiomas. The local control is comparable to that reported following conventional external beam RT. Longer follow-up is required to assess long term efficacy and toxicity, particularly in terms of potential reduction of treatment-related late toxicity

  3. Observation of hypoxia in HNSCC xenografts during fractionated radiotherapy

    Full text: This experimental study was performed to observe hypoxia within tumour xenografts using the 2-nitroimidazole oxygen binding agent, Pimonidazole. Xenografts were subjected to 6 MV fractionated radiotherapy to enable the changes in hypoxia to be assessed throughout treatment. The xenografts were grown in immuno-deficient mice through subcutaneously injection (FaOu cell line) 8 days prior to treatment, with all mice growing visible tumours ranging between 2 and 6 mm in diameter. An irradiation schedule of 5 x 3 Gy in week I and 5 x 5 Gy in week 2 was delivered using a novel restraining system to unanaesthetised mice. Pimonidazole was injected into 17 mice that had received 0, 3, 9, 20, 30 or 40 Gy. Immunohistochemical imaging processes were performed on xenograft cross-sections to observe hypoxia as well as proliferative (blue-BrdUrd) and endothelial blood vessel cells (red-Hoechst 33342). In vivo oxygenation levels were also recorded using the OxyLab fluorescent probe system to provide a concurrent quantitative oxygenation analysis. Cross-sectional fluorescent images confirmed the presence of hypoxia (pO2 < 10 mmHg), which decreased with radiation dose and tumour volume. Images illustrated the microscopic spatial and chaotic nature of cellular hypoxia in the tumours. OxyLab results confirmed quantitatively that the xenografts had low levels of oxygenation, which increased late in the schedule (after 40 Gy).

  4. Accelerated radiotherapy for T1, 2 glottic carcinoma: analysis of results with KI-67 index

    Purpose: Hyperfractionated and accelerated radiotherapy without a split was performed to improve the local control probability of early glottic carcinomas. We analyzed the results of this regimen by using the Ki-67 index. Methods and Materials: Over a 12-year period, 85 T1N0M0 glottic cancers and 50 T2N0M0 glottic cancers were treated with conventional fractionation (CF) from 1984 to 1989 and with accelerated fractionation (AF) since 1990. The CF program consisted of five daily fractions of 2 Gy per week, for a total of 64 Gy. The AF program consisted of 1.72 Gy per fraction, two fractions per day, 5 days a week, for a total of 55 or 58 Gy. The specimens, taken before radiotherapy, were immunohistochemically stained with anti-Ki-67 antibody. Results: The 5-year local control probability for T1 tumors was 79.6 ± 6.9% with CF treatment, whereas with AF it was 86.9 ± 5.6%. For T2 tumors it was 62.7 ± 12.2% with CF, whereas it was 74.7 ± 7.8% with AF. The difference between CF and AF did not reach the point of statistical significance. However, when T1 tumors had a Ki-67 index lower than 50%, the local control rate achieved with AF was significantly better than that with CF (p = 0.018). When the tumors had a Ki-67 index that was 50% or more, there was no difference in the local control rate between CF and AF, whether they were T1 or T2. The peak mucosal reactions at the larynx and/or hypopharynx were much more severe and appeared at smaller doses and earlier in AF than in CF. The patients with AF showed no severe late complications. Conclusions: AF could not obtain statistically significant improvement in local control probability of T1 or T2 glottic carcinomas

  5. Accelerated Deformable Registration of Repetitive MRI during Radiotherapy in Cervical Cancer

    Noe, Karsten Østergaard; Tanderup, Kari; Kiritsis, Christian; Dimopoulos, Johannes; Sørensen, Thomas Sangild; Lindegaard, Jacob; Grau, Cai

    Tumour regression and organ deformations during radiotherapy (RT) of cervical cancer represent major challenges regarding accurate conformation and calculation of dose when using image-guided adaptive radiotherapy. Deformable registration algorithms are able to handle organ deformations, which can...... be useful with advanced tools such as auto segmentation of organs and dynamic adaptation of radiotherapy. The aim of this study was to accelerate and validate deformable registration in MRI-based image-guided radiotherapy of cervical cancer.    ...

  6. Randomized study on late course accelerated hyperfractionation radiotherapy plus cisplatin in the treatment of esophageal carcinomas

    Objective: To investigate the therapeutic results of late course accelerated hyperfractionation (LCAH) radiotherapy plus cisplatin as a radiosensitizer in the treatment of esophageal carcinoma. Methods: One hundred and four patients with squamou s cell carcinoma of the esophagus were randomized into two groups: LCAH alone group (53 patients) and LCAH + cisplatin group (51 patients). The same irradiation technique was given for both groups with conventional fractionation (2 Gy daily, 5 times a week) in the first 3 weeks and late course accelerated hyperfractionation (1.5 Cry twice daily, a minimum interfraction interval of 6 hours, 5 days per week) in the last 2 weeks. The total dose was 60 Gy/5 wks. In LCAH + cisplatin group, cisplatin was given simultaneous with 20 mg once daily for 5 days in the 1st and 5th weeks. The acute and late side effects were evaluated during :and after the treatment. Results: The median survival time was 12.2 months and 17.0 months in the LCAH alone group and LCAH + cisplatin group. The 1- and 3-year survival rates in LCAH group were 52.8 % and 20.8%; while those of LCAH + cisplatin group were 58.0 % and 24.0% (P>0.05). The acute gastrointestinal toxicities and hematological toxicities were obvious in LCAH + cisplatin group, but no increased acute esophagitis or late complications was observed. Conclusions: Late course accelerated hyperfractionation radio-therapy used simultaneously with cisplatin tends to increase the overall survival rate compared with the late course accelerated hyperfractionation radiotherapy alone in the treatment of esophageal carcinoma. (authors)

  7. Hypofractionated and Accelerated Radiotherapy With Subcutaneous Amifostine Cytoprotection as Short Adjuvant Regimen After Breast-Conserving Surgery: Interim Report

    Purpose: Short radiotherapy schedules might be more convenient for patients and overloaded radiotherapy departments, provided late toxicity is not increased. We evaluated the efficacy and toxicity of a hypofractionated and highly accelerated radiotherapy regimen supported with cytoprotection provided by amifostine in breast cancer patients treated with breast-conserving surgery. Methods and Materials: A total of 92 patients received 12 consecutive fractions of radiotherapy (3.5 Gy/fraction for 10 fractions) to the breast and/or axillary/supraclavicular area and 4 Gy/fraction for 2 fractions to the tumor bed). Amifostine at a dose of 1,000 mg/d was administered subcutaneously. The follow-up of patients was 30-60 months (median, 39). Results: Using a dose individualization algorithm, 77.1% of patients received 1,000 mg and 16.3% received 750 mg of amifostine daily. Of the 92 patients, 13% interrupted amifostine because of fever/rash symptoms. Acute Grade 2 breast toxicity developed in 6.5% of patients receiving 1,000 mg of amifostine compared with 46.6% of the rest of the patients (p < .0001). The incidence of Grade 2 late sequelae was less frequent in the high amifostine dose group (3.2% vs. 6.6%; p = NS). Grade 1 lung fibrosis was infrequent (3.3%). The in-field relapse rate was 3.3%, and an additional 2.2% of patients developed a relapse in the nonirradiated supraclavicular area. c-erbB-2 overexpression was linked to local control failure (p = .01). Distant metastasis appeared in 13% of patients, and this was marginally related to more advanced T/N stage (p = .06). Conclusion: Within a minimal follow-up of 2.5 years after therapy, hypofractionated and accelerated radiotherapy with subcutaneous amifostine cytoprotection has proved a well-tolerated and effective regimen. Longer follow-up is required to assess the long-term late sequelae.

  8. Endocrine and visual function after fractionated stereotactic radiotherapy of perioptic tumors

    Purpose: To find out whether the use of stereotactic techniques for fractionated radiotherapy reduces toxicity to the endocrine and visual system in patients with benign perioptic tumors. Patients and methods: From 1993 to 2009, 29 patients were treated with fractionated stereotactic radiotherapy. The most frequent tumor types were grade I meningioma (n = 11) and pituitary adenoma (n = 10, 7 nonfunctioning, 3 growth hormone-producing). Patients were immobilized with the GTC frame (Radionics, USA) and the planning target volume (PTV; median 24.7, 4.6-58.6 ml) was irradiated with a total dose of 52.2 Gy (range, 45.0-55.8 Gy) in 1.8-Gy fractions using a linear accelerator (6 MeV photons) equipped with a micro-multileaf collimator. Maximum doses to the optic system and pituitary gland were 53.4 Gy (range, 11.5-57.6 Gy) and 53.6 Gy (range, 12.0-57.9 Gy). Results: Median follow-up was 45 months (range, 10-105 months). Local control was achieved in all but 1 patient (actuarial rate 92% at 5 years and 10 years). In 9 of 29 patients (31%), partial remission was observed (actuarial response rate 40% at 5 years and 10 years). In 4 of 26 patients (15%) with at least partial pituitary function, new hormonal deficits developed (actuarial rate 21% at 5 years and 10 years). This rate was significantly higher in patients treated for a larger PTV ( 25 ml: 0% vs. 42% at 5 years and 10 years, p = 0.028). Visual function improved in 4 of 15 patients (27%) who had prior impairment. None of the patients developed treatment-related optic neuropathy, but 2 patients experienced new disease-related visual deficits. Conclusion: Fractionated stereotactic radiotherapy for benign tumors of the perioptic and sellar region results in satisfactory response and local control rates and does not affect the visual system. The assumption that patients can be spared hypophyseal insufficiency only holds for small tumors. (orig.)

  9. Endocrine and visual function after fractionated stereotactic radiotherapy of perioptic tumors

    Kocher, M.; Semrau, R.; Mueller, R.P. [Universitaetsklinikum Koeln (Germany). Klinik und Poliklinik fuer Strahlentherapie; Treuer, H.; Hoevels, M.; Sturm, V. [Koeln Univ. (Germany). Dept. of Stereotaxy and Functional Neurosurgery

    2013-02-15

    Purpose: To find out whether the use of stereotactic techniques for fractionated radiotherapy reduces toxicity to the endocrine and visual system in patients with benign perioptic tumors. Patients and methods: From 1993 to 2009, 29 patients were treated with fractionated stereotactic radiotherapy. The most frequent tumor types were grade I meningioma (n = 11) and pituitary adenoma (n = 10, 7 nonfunctioning, 3 growth hormone-producing). Patients were immobilized with the GTC frame (Radionics, USA) and the planning target volume (PTV; median 24.7, 4.6-58.6 ml) was irradiated with a total dose of 52.2 Gy (range, 45.0-55.8 Gy) in 1.8-Gy fractions using a linear accelerator (6 MeV photons) equipped with a micro-multileaf collimator. Maximum doses to the optic system and pituitary gland were 53.4 Gy (range, 11.5-57.6 Gy) and 53.6 Gy (range, 12.0-57.9 Gy). Results: Median follow-up was 45 months (range, 10-105 months). Local control was achieved in all but 1 patient (actuarial rate 92% at 5 years and 10 years). In 9 of 29 patients (31%), partial remission was observed (actuarial response rate 40% at 5 years and 10 years). In 4 of 26 patients (15%) with at least partial pituitary function, new hormonal deficits developed (actuarial rate 21% at 5 years and 10 years). This rate was significantly higher in patients treated for a larger PTV ( 25 ml: 0% vs. 42% at 5 years and 10 years, p = 0.028). Visual function improved in 4 of 15 patients (27%) who had prior impairment. None of the patients developed treatment-related optic neuropathy, but 2 patients experienced new disease-related visual deficits. Conclusion: Fractionated stereotactic radiotherapy for benign tumors of the perioptic and sellar region results in satisfactory response and local control rates and does not affect the visual system. The assumption that patients can be spared hypophyseal insufficiency only holds for small tumors. (orig.)

  10. Fractionated Stereotactic Radiotherapy in Patients With Optic Nerve Sheath Meningioma

    Purpose: To evaluate the effectiveness of fractionated stereotactic radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). Methods and Materials: Between 1993 and 2005, 109 patients (113 eyes) with primary (n = 37) or secondary (n = 76) ONSM were treated according to a prospective protocol with SFRT to a median dose of 54 Gy. All patients underwent radiographic, ophthalmologic, and endocrine analysis before and after SFRT. Radiographic response, visual control, and late side effects were endpoints of the analysis. Results: Median time to last clinical, radiographic, and ophthalmologic follow up was 30.2 months (n = 113), 42.7 months (n = 108), and 53.7 months (n = 91), respectively. Regression of the tumor was observed in 5 eyes and progression in 4 eyes, whereas 104 remained stable. Visual acuity improved in 12, deteriorated in 11, and remained stable in 68 eyes. Mean visual field defects reduced from 33.6% (n = 90) to 17.8% (n = 56) in ipsilateral and from 10% (n = 94) to 6.7% (n = 62) in contralateral eyes. Ocular motility improved in 23, remained stable in 65, and deteriorated in 3 eyes. Radiographic tumor control was 100% at 3 years and 98% at 5 years. Visual acuity was preserved in 94.8% after 3 years and in 90.9% after 5 years. Endocrine function was normal in 90.8% after 3 years and in 81.3% after 5 years. Conclusions: SFRT represents a highly effective treatment for ONSM. Interdisciplinary counseling of the patients is recommended. Because of the high rate of preservation of visual acuity we consider SFRT the standard approach for the treatment of ONSM. Prolonged observation is warranted to more accurately assess late visual impairment. Moderate de-escalation of the radiation dose might improve the preservation of visual acuity and pituitary gland function.

  11. Conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas

    Purpose: Analysis of local tumor control and functional outcome following conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas. Patients and Methods: From 11/1989 to 9/1999 51 patients with acoustic neuromas have been treated by FSRT. Mean total dose was 57.6 ± 2.5 Gy. Forty-two patients have been followed for at least 12 months and were subject of an outcome analysis. Mean follow-up was 42 months. We analyzed local control, hearing preservation, and facial and trigeminal nerve functional preservation. We evaluated influences of tumor size, age, and association with neurofibromatosis Type 2 (NF2) on outcome and treatment related toxicity. Results: Actuarial 2- and 5-year tumor control rates were 100% and 97.7%, respectively. Actuarial useful hearing preservation rate was 85% at 2 and 5 years. New hearing loss was diagnosed in 4 NF2 patients. Pretreatment normal facial nerve function was preserved in all cases. Two cases of new or impaired trigeminal nerve dysesthesia required medication. No other cranial nerve deficit was observed. In Patients without NF2 tumor size or age had no influence on tumor control and cranial nerve toxicity. Diagnosis of NF2 was associated with higher risk of hearing impairment (p 0.0002), the hearing preservation rate in this subgroup was 60%. Conclusion: FSRT has been shown to be an effective means of local tumor control. Excellent hearing preservation rates and 5th and 7th nerve functional preservation rates were achieved. The results support the conclusion that FSRT can be recommended to patients with acoustic neuromas where special attention has to be taken to preserve useful hearing and normal cranial nerve function. For NF2 patients, FSRT may be the treatment of choice with superior functional outcome compared to treatment alternatives.

  12. Fractionated Stereotactic Radiotherapy in Patients With Optic Nerve Sheath Meningioma

    Paulsen, Frank, E-mail: frank.paulsen@med.uni-tuebingen.de [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Doerr, Stefan [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Wilhelm, Helmut [Department of Ophthalmology, University of Tuebingen, Tuebingen (Germany); Becker, Gerd [Department of Radiation Oncology, Klinik am Eichert, Goeppingen (Germany); Bamberg, Michael [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Classen, Johannes [Department of Radiation Oncology, St. Vincentius-Kliniken, Karlsruhe (Germany)

    2012-02-01

    Purpose: To evaluate the effectiveness of fractionated stereotactic radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). Methods and Materials: Between 1993 and 2005, 109 patients (113 eyes) with primary (n = 37) or secondary (n = 76) ONSM were treated according to a prospective protocol with SFRT to a median dose of 54 Gy. All patients underwent radiographic, ophthalmologic, and endocrine analysis before and after SFRT. Radiographic response, visual control, and late side effects were endpoints of the analysis. Results: Median time to last clinical, radiographic, and ophthalmologic follow up was 30.2 months (n = 113), 42.7 months (n = 108), and 53.7 months (n = 91), respectively. Regression of the tumor was observed in 5 eyes and progression in 4 eyes, whereas 104 remained stable. Visual acuity improved in 12, deteriorated in 11, and remained stable in 68 eyes. Mean visual field defects reduced from 33.6% (n = 90) to 17.8% (n = 56) in ipsilateral and from 10% (n = 94) to 6.7% (n = 62) in contralateral eyes. Ocular motility improved in 23, remained stable in 65, and deteriorated in 3 eyes. Radiographic tumor control was 100% at 3 years and 98% at 5 years. Visual acuity was preserved in 94.8% after 3 years and in 90.9% after 5 years. Endocrine function was normal in 90.8% after 3 years and in 81.3% after 5 years. Conclusions: SFRT represents a highly effective treatment for ONSM. Interdisciplinary counseling of the patients is recommended. Because of the high rate of preservation of visual acuity we consider SFRT the standard approach for the treatment of ONSM. Prolonged observation is warranted to more accurately assess late visual impairment. Moderate de-escalation of the radiation dose might improve the preservation of visual acuity and pituitary gland function.

  13. Changes in serum and salivary amylase during radiotherapy for head and neck cancer; A comparison of conventionally fractionated radiotherapy with CHART

    Leslie, M.D.; Dische, S. (Mount Vernon Hospital, Northwood (United Kingdom))

    1992-05-01

    The changes in serum amylase that occur when radiotherapy is given in the treatment of head and neck cancer has been studied in 41 patients, 29 treated by CHART and 12 by conventionally fractionated radiotherapy. The peak rise in serum amylase following the start of treatment is seen earlier and is greater in the patients receiving continuous hyperfractionated accelerated radiotherapy (CHART). The serum amylase returns to normal earlier in the CHART patients so that the area under the curve is the same for both groups. The difference probably reflects the more rapid delivery of treatment to the patients receiving CHART. A close correlation between the peak rise in serum amylase and the amount of parotid tissue in the treatment volume is demonstrated. For six patients the total amount of amylase secreted by the parotid gland during CHART was measured and found to decline rapidly within a few days of the start of radiotherapy. The rise in serum amylase that results from the irradiation of salivary tissue provides a unique biochemical measure of an early radiation effect in a normal tissue. This probably reflects the interphase cell death of serous salivary cells. Although these immediate changes are of considerable interest they may not relate to the late effects of radiation on salivary gland function. (author). 13 refs.; 4 figs.

  14. Not traditional regimes of radiotherapeutic dose fractionation as modifier of radiotherapy for carcinoma of lungs

    The efficiency of applying various of radiotherapeutic dose fractionation was analyzed. The results of the own studies performed at the Scientific and Research Institute of Oncology and Medical Radiology for elaborating not traditional regimes of radiotherapeutic dose fractionation (a dynamic fractionation applying enlarged regimes at the first stage and the classic ones at the second stage) were presented. Appliance of the modified radiotherapy for the epidermoid carcinoma of the lungs allowed to increase the objective response from 45,3+-3% to 80+-5% the tumor disappearing completely in 40+-6% of patients as compared with 10+-2%. Appliance of the intensive not traditional variant of the radiotherapy dynamic fractionation in case of a small cell carcinoma of the lungs resulted in the therapy duration reduction from 6 to 4 weeks. Thus the not traditional dose fractionation might become a mechanism for the improving the radiotherapy of persons suffering from the carcinoma of the lungs. (authors)

  15. Prostate stereotactic ablative body radiotherapy using a standard linear accelerator: Toxicity, biochemical, and pathological outcomes

    Background and purpose: Biological dose escalation through stereotactic ablative radiotherapy (SABR) holds promise of improved patient convenience, system capacity and tumor control with decreased cost and side effects. The objectives are to report the toxicities, biochemical and pathologic outcomes of this prospective study. Materials and methods: A phase I/II study was performed where low risk localized prostate cancer received SABR 35 Gy in 5 fractions, once weekly on standard linear accelerators. Common Terminology Criteria for Adverse Events v3.0 and Radiation Therapy Oncology Group late morbidity scores were used to assess acute and late toxicities, respectively. Biochemical control (BC) was defined by the Phoenix definition. Results: As of May 2012, 84 patients have completed treatment with a median follow-up of 55 months (range 13–68 months). Median age was 67 years and median PSA was 5.3 ng/ml. The following toxicities were observed: acute grade 3+: 0% gastrointestinal (GI), 1% genitourinary (GU), 0% fatigue; late grade 3+: 1% GI, 1% GU. Ninety-six percent were biopsy negative post-treatment. The 5-year BC was 98%. Conclusions: This novel technique employing standard linear accelerators to deliver an extreme hypofractionated schedule of radiotherapy is feasible, well tolerated and shows excellent pathologic and biochemical control

  16. Impact of dose size in single fraction spatially fractionated (grid) radiotherapy for melanoma

    Zhang, Hualin, E-mail: hualin.zhang@northwestern.edu, E-mail: hualinzhang@yahoo.com [Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States); Zhong, Hualiang [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan 48202 (United States); Barth, Rolf F. [Department of Pathology, The Ohio State University, Columbus, Ohio 43210 (United States); Cao, Minsong; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)

    2014-02-15

    Purpose: To evaluate the impact of dose size in single fraction, spatially fractionated (grid) radiotherapy for selectively killing infiltrated melanoma cancer cells of different tumor sizes, using different radiobiological models. Methods: A Monte Carlo technique was employed to calculate the 3D dose distribution of a commercially available megavoltage grid collimator in a 6 MV beam. The linear-quadratic (LQ) and modified linear quadratic (MLQ) models were used separately to evaluate the therapeutic outcome of a series of single fraction regimens that employed grid therapy to treat both acute and late responding melanomas of varying sizes. The dose prescription point was at the center of the tumor volume. Dose sizes ranging from 1 to 30 Gy at 100% dose line were modeled. Tumors were either touching the skin surface or having their centers at a depth of 3 cm. The equivalent uniform dose (EUD) to the melanoma cells and the therapeutic ratio (TR) were defined by comparing grid therapy with the traditional open debulking field. The clinical outcomes from recent reports were used to verify the authors’ model. Results: Dose profiles at different depths and 3D dose distributions in a series of 3D melanomas treated with grid therapy were obtained. The EUDs and TRs for all sizes of 3D tumors involved at different doses were derived through the LQ and MLQ models, and a practical equation was derived. The EUD was only one fifth of the prescribed dose. The TR was dependent on the prescribed dose and on the LQ parameters of both the interspersed cancer and normal tissue cells. The results from the LQ model were consistent with those of the MLQ model. At 20 Gy, the EUD and TR by the LQ model were 2.8% higher and 1% lower than by the MLQ, while at 10 Gy, the EUD and TR as defined by the LQ model were only 1.4% higher and 0.8% lower, respectively. The dose volume histograms of grid therapy for a 10 cm tumor showed different dosimetric characteristics from those of conventional

  17. High dose rate fractionated interstitial radiotherapy for prostate cancer

    Nose, Takayuki; Inoue, Takehiro; Inoue, Toshihiko [Osaka Univ., Suita (Japan). Medical School] [and others

    1996-12-01

    From January 1993 through June 1996, thirteen advanced prostate cancer cases were treated with high dose rate interstitial radiotherapy using TRUS and perineal template guidance combined with or without external radiotherapy. Among eight cases eligible for local control, only one case relapsed so far. One perineal skin necrosis and one total incontinence were experienced in the patients treated with non-standard protocol dose. No apparent side effects were found in standard treatment patients. In addition with markedly increased tumor dose local control rate can be improved. (author)

  18. HIGH DOSE FRACTION RADIOTHERAPY FOR MUCOSAL MALIGNANT MELANOMA OF THE HEAD AND NECK

    Liu Xiuying; Li Huiling; Zheng Tianrong; Lin Xiangsong

    1998-01-01

    Objective:To evatuate the results of high dose fraction radiotherapy for mucosal malignant melanoma of the head and neck (HNMM). Methods: From 1984-1994, 35 patients with HNMM were enrolled in this study. Among them, 27 cases localized to the nasal cavity or para-nasal sinus, 8 to the oral cavity. All patients received high dose fraction radiotherapy (6--8 Gy/fraction)with the total dose ranged from 40 to 60 Gy. Results: The minimum follow-up was 2 years (ranged 2-7 years). The overall 3- and 5-year survival rate was 45.7% and 24%,respectively. Conclusion: High dose fraction radiotherapy is effective for local control of HNMM.

  19. Initial experience of single fraction radiotherapy (8 Gy x 1) in the treatment of painful bone metastases

    Sixteen patients with painful bone metastases received single fraction radiotherapy of 8 Gy. Single fraction radiotherapy was effective in providing pain relief with response rate of 88.8%. There were no severe acute side effects. The therapeutic regimen was also safe and effective in patients with poor performance status and poor prognosis. Therefore single fraction radiotherapy should be considered to treat pain arising from bone metastases. (author)

  20. Salvage surgery after radical accelerated radiotherapy with concomitant boost technique for head and neck carcinomas

    Taussky, Daniel; Dulguerov, Pavel; Allal, Abdelkarim Said

    2005-01-01

    Definitive radiotherapy (RT) for head and neck cancer is increasingly used to preserve organ function, whereas surgery is reserved for treatment failure. However, data are sparse regarding the feasibility of salvage surgery, particularly for unselected patients after accelerated RT.

  1. Effect of fractionated regional external beam radiotherapy on peripheral blood cell count

    Purpose: The purpose of this study was to assess the need for obtaining weekly complete blood count (CBC) values and to identify the pattern of changes in CBC during regional conventional fractionated radiotherapy. Methods and Materials: A retrospective analysis of CBC data on 299 adult cancer patients who received definitive conventional radiotherapy to head and neck (n=95), chest (n=96), and pelvis (n=108) was performed. Temporal patterns and magnitude of change in white blood cells, neutrophils, lymphocytes, and platelets during radiotherapy were examined. Results: There were statistically significant declines in all counts, albeit not clinically significant. Notable differences between disease sites were found. The greatest weekly interval change in counts occurred during the first week of radiotherapy for all groups of patients. The mean WBC nadir values during treatment were 5.8 for head and neck, 6.8 for chest, and 5.4 for pelvis. The nadirs for all counts occurred toward the middle-to-end of radiotherapy. Lymphocytes were found to be more sensitive to radiotherapy than other leukocyte subcomponents. Conclusion: Our study suggests that weekly CBC monitoring is not necessary for all patients undergoing standard fractionated radiotherapy. Baseline blood counts may be used to determine an optimal schedule for monitoring CBCs in patients receiving conventional radiation alone. Reduced monitoring of CBC may result in significant financial savings

  2. Challenges in Linear Accelerator Radiotherapy for Chordomas and Chondrosarcomas of the Skull Base: Focus on Complications

    Hauptman, Jason S., E-mail: jhauptman@mednet.ucla.edu [Division of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); Barkhoudarian, Garni; Safaee, Michael; Gorgulho, Alessandra [Division of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); Tenn, Steven; Agazaryan, Nzhde; Selch, Michael [Department of Radiation Oncology, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); De Salles, Antonio A.F. [Division of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); Department of Radiation Oncology, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States)

    2012-06-01

    Purpose: Intracranial chordomas and chondrosarcomas are histologically low-grade, locally invasive tumors that infiltrate the skull base. Currently, consensus therapy includes surgical resection and adjuvant radiotherapy. Radiation delivery is typically limited by the proximity of these tumors to critical skull base structures. Methods: This is a retrospective review of 13 cases of chordomas and 2 cases of chondroid chondrosarcomas of the skull based treated with linear accelerator stereotactic radiotherapy (SRT, n = 10) or stereotactic radiosurgery (SRS, n = 5). The average time to the most recent follow-up visit was 4.5 years. The tumor characteristics, treatment details, and outcomes were recorded. Each radiation plan was reviewed, and the dosage received by the brainstem, optic apparatus, and pituitary was calculated. Results: Of the 10 patients treated with SRT, 6 were found to have unchanged or decreased tumor size as determined from radiographic follow-up. Of the 5 patients treated with SRS, 3 were found to have stable or unchanged tumors at follow-up. The complications included 1 SRT patient who developed endocrinopathy, 2 patients (1 treated with SRS and the other with SRT), who developed cranial neuropathy, and 1 SRS patient who developed visual deficits. Additionally, 1 patient who received both SRS and SRT within 2 years for recurrence experienced transient medial temporal lobe radiation changes that resolved. Conclusions: Where proton beam therapy is unavailable, linear accelerator-based SRT or radiosurgery remains a safe option for adjuvant therapy of chordomas and chondrosarcomas of the skull base. The exposure of the optic apparatus, pituitary stalk, and brainstem must be considered during planning to minimize complications. If the optic apparatus is included in the 80% isodose line, it might be best to fractionate therapy. Exposure of the pituitary stalk should be kept to <30 Gy to minimize endocrine dysfunction. Brainstem exposure should be

  3. Challenges in Linear Accelerator Radiotherapy for Chordomas and Chondrosarcomas of the Skull Base: Focus on Complications

    Purpose: Intracranial chordomas and chondrosarcomas are histologically low-grade, locally invasive tumors that infiltrate the skull base. Currently, consensus therapy includes surgical resection and adjuvant radiotherapy. Radiation delivery is typically limited by the proximity of these tumors to critical skull base structures. Methods: This is a retrospective review of 13 cases of chordomas and 2 cases of chondroid chondrosarcomas of the skull based treated with linear accelerator stereotactic radiotherapy (SRT, n = 10) or stereotactic radiosurgery (SRS, n = 5). The average time to the most recent follow-up visit was 4.5 years. The tumor characteristics, treatment details, and outcomes were recorded. Each radiation plan was reviewed, and the dosage received by the brainstem, optic apparatus, and pituitary was calculated. Results: Of the 10 patients treated with SRT, 6 were found to have unchanged or decreased tumor size as determined from radiographic follow-up. Of the 5 patients treated with SRS, 3 were found to have stable or unchanged tumors at follow-up. The complications included 1 SRT patient who developed endocrinopathy, 2 patients (1 treated with SRS and the other with SRT), who developed cranial neuropathy, and 1 SRS patient who developed visual deficits. Additionally, 1 patient who received both SRS and SRT within 2 years for recurrence experienced transient medial temporal lobe radiation changes that resolved. Conclusions: Where proton beam therapy is unavailable, linear accelerator-based SRT or radiosurgery remains a safe option for adjuvant therapy of chordomas and chondrosarcomas of the skull base. The exposure of the optic apparatus, pituitary stalk, and brainstem must be considered during planning to minimize complications. If the optic apparatus is included in the 80% isodose line, it might be best to fractionate therapy. Exposure of the pituitary stalk should be kept to <30 Gy to minimize endocrine dysfunction. Brainstem exposure should be

  4. Five Year Outcome of 145 Patients With Ductal Carcinoma In Situ (DCIS) After Accelerated Breast Radiotherapy

    Background: Accelerated whole-breast radiotherapy (RT) with tumor bed boost in the treatment of early invasive breast cancer has demonstrated equivalent local control and cosmesis when compared with standard RT. Its efficacy in the treatment of ductal carcinoma in situ (DCIS) remains unknown. Methods and Materials: Patients treated for DCIS with lumpectomy and negative margins were eligible for 2 consecutive hypofractionated whole-breast RT clinical trials. The first trial (New York University [NYU] 01-51) prescribed to the whole breast 42 Gy (2.8 Gy in 15 fractions) and the second trial (NYU 05-181) 40.5 Gy (2.7 Gy in 15 fractions) with an additional daily boost of 0.5 Gy to the surgical cavity. Results: Between 2002 and 2009, 145 DCIS patients accrued, 59 to the first protocol and 86 to the second trial. Median age was 56 years and 65% were postmenopausal at the time of treatment. Based on optimal sparing of normal tissue, 79% of the patients were planned and treated prone and 21% supine. At 5 years' median follow-up (60 months; range 2.6-105.5 months), 6 patients (4.1%) experienced an ipsilateral breast recurrence in all cases of DCIS histology. In 3/6 patients, recurrence occurred at the original site of DCIS and in the remaining 3 cases outside the original tumor bed. New contralateral breast cancers arose in 3 cases (1 DCIS and 2 invasive carcinomas). Cosmetic self-assessment at least 2 years after treatment is available in 125 patients: 91% reported good-to-excellent and 9% reported fair-to-poor outcomes. Conclusions: With a median follow-up of 5 years, the ipsilateral local recurrence rate is 4.1%, comparable to that reported from the NSABP (National Surgical Adjuvant Breast and Bowel Project) trials that employed 50 Gy in 25 fractions of radiotherapy for DCIS. There were no invasive recurrences. These results provide preliminary evidence that accelerated hypofractionated external beam radiotherapy is a viable option for DCIS.

  5. Five Year Outcome of 145 Patients With Ductal Carcinoma In Situ (DCIS) After Accelerated Breast Radiotherapy

    Ciervide, Raquel [Department of Radiation Oncology, New York University School of Medicine, NYU Langone Medical Center, New York, New York (United States); Dhage, Shubhada; Guth, Amber; Shapiro, Richard L.; Axelrod, Deborah M.; Roses, Daniel F. [Department of Surgery, New York University School of Medicine, NYU Langone Medical Center, New York, New York (United States); Formenti, Silvia C., E-mail: silvia.formenti@nyumc.org [Department of Radiation Oncology, New York University School of Medicine, NYU Langone Medical Center, New York, New York (United States)

    2012-06-01

    Background: Accelerated whole-breast radiotherapy (RT) with tumor bed boost in the treatment of early invasive breast cancer has demonstrated equivalent local control and cosmesis when compared with standard RT. Its efficacy in the treatment of ductal carcinoma in situ (DCIS) remains unknown. Methods and Materials: Patients treated for DCIS with lumpectomy and negative margins were eligible for 2 consecutive hypofractionated whole-breast RT clinical trials. The first trial (New York University [NYU] 01-51) prescribed to the whole breast 42 Gy (2.8 Gy in 15 fractions) and the second trial (NYU 05-181) 40.5 Gy (2.7 Gy in 15 fractions) with an additional daily boost of 0.5 Gy to the surgical cavity. Results: Between 2002 and 2009, 145 DCIS patients accrued, 59 to the first protocol and 86 to the second trial. Median age was 56 years and 65% were postmenopausal at the time of treatment. Based on optimal sparing of normal tissue, 79% of the patients were planned and treated prone and 21% supine. At 5 years' median follow-up (60 months; range 2.6-105.5 months), 6 patients (4.1%) experienced an ipsilateral breast recurrence in all cases of DCIS histology. In 3/6 patients, recurrence occurred at the original site of DCIS and in the remaining 3 cases outside the original tumor bed. New contralateral breast cancers arose in 3 cases (1 DCIS and 2 invasive carcinomas). Cosmetic self-assessment at least 2 years after treatment is available in 125 patients: 91% reported good-to-excellent and 9% reported fair-to-poor outcomes. Conclusions: With a median follow-up of 5 years, the ipsilateral local recurrence rate is 4.1%, comparable to that reported from the NSABP (National Surgical Adjuvant Breast and Bowel Project) trials that employed 50 Gy in 25 fractions of radiotherapy for DCIS. There were no invasive recurrences. These results provide preliminary evidence that accelerated hypofractionated external beam radiotherapy is a viable option for DCIS.

  6. Cyberknife fractionated radiotherapy for adrenal metastases: Preliminary report from a multispecialty Indian cancer care center

    Trinanjan Basu

    2015-03-01

    Full Text Available Purpose: Metastasis to adrenal gland from lung, breast, and kidney malignancies are quite common. Historically radiotherapy was intended for pain palliation. Recent studies with stereotactic body radiotherapy (SBRT including Cyberknife robotic radiosurgery aiming at disease control brings about encouraging results. Here we represent the early clinical experience with Cyberknife stereotactic system from an Indian cancer care center. The main purpose of this retrospective review is to serve as a stepping stone for future prospective studies with non- invasive yet effective technique compared to surgery. Methods: We retrospectively reviewed four cases of adrenal metastases (three: lung and one: renal cell carcinoma treated with Cyberknife SBRT. X sight spine tracking was employed for planning and treatment delivery. Patients were evaluated for local response clinically as well as with PETCT based response criteria.Results: With a median gross tumor volume of 20.5 cc and median dose per fraction of 10 Gy, two patients had complete response (CR and two had partial response (PR when assessed 8-12 weeks post treatment as per RECIST. There was no RTOG grade 2 or more acute adverse events and organs at risk dosage were acceptable. Till last follow up all the patients were locally controlled and alive. Conclusion: Cyberknife SBRT with its unique advantages like non- invasive, short duration outpatient treatment technique culminating in similar local control rates in comparison to surgery is an attractive option. World literature of linear accelerator based SBRT and our data with Cyberknife SBRT with small sample size and early follow up are similar in terms of local control in adrenal metastases. Future prospective data would reveal more information on the management of adrenal metastases.

  7. The role of accelerated hyperfractionated radiotherapy in the treatment of inoperable non-small cell lung cancer: a controlled clinical trial

    Radiotherapy remains the basic form of treatment in cases of non-small cell lung cancer (NSCLC) but there still exist controversies concerning optimal radiotherapy regimen and in particular, the total dose and fractionation schedules. To prove whether the question: if using an unconventional dose fractionation regimen (accelerated hyperfractionation) could improve the results of palliative teleradiotherapy patients with NSCLC. Between 1997 and 2000 in the Cancer Centre in Cracow (COOK) a controlled clinical trial was conducted in a group of 150 patients with locally advanced (III Deg) inoperable and unsuitable for radical radiotherapy NSCLC, with no major symptoms of the disease. In 76 patients conventionally fractionated radiotherapy was performed - 50 Gy in 25 fractions during 5 weeks (CF). 74 patients were irradiated twice a day (AHF); the dose per fraction was 1.25 Gy and the minimum interval between fractions - 6 hours. The total dose was 50 Gy in 40 fractions during 26 days. The probability of 12 months survival was 47.4% in the CF arm and 45.9% in the AHF arm; the probability of 24 months survival was 16.2% and 15.8%, respectively. In all 76 patients in CF arm the treatment was carried out in prescribed time without breaks. Out of 74 patients in the A HF group 8 (10,8%) did not complete the treatment and 2 of then died in 3rd and 4th week of treatment. The use of accelerated hyperfractionation does not improve the results of palliative teleradiotherapy in patients with locally advanced NSCLC without severe symptoms related to intrathoracic tumor. The treatment of choice in this group of patients os conventionally fractionated radiotherapy with a total dose of 50 Gy in 25 fractions in 5 week of treatment. (author)

  8. DCEMRI of spontaneous canine tumors during fractionated radiotherapy: A pharmacokinetic analysis

    Purpose: To estimate pharmacokinetic parameters from dynamic contrast-enhanced magnetic resonance (DCEMR) images of spontaneous canine tumors taken during the course of fractionated radiotherapy, and to quantify treatment-induced changes in these parameters. Materials and methods: Six dogs with tumors in the oral or nasal cavity received fractionated conformal radiotherapy with 54 Gy given in 18 fractions. T1-weighted DCEMR imaging was performed prior to each treatment fraction. Time-intensity curves in the tumor were extracted voxel-by-voxel, and were fitted to the Brix pharmacokinetic model. The dependence of the pharmacokinetic parameters on the accumulated radiation dose was calculated. Results: The Brix model reproduced the time-intensity curves well. A reduction in the kep parameter with accumulated radiation dose was found for five (three significant) out of six cases, while the results for the A parameter were less consistent. Both pre-treatment kep and the change in kep with accumulated dose correlated significantly with tumor regression. Conclusions: Pharmacokinetic parameters derived from DCEMR images taken during fractionated radiotherapy may predict response to radiotherapy. This may potentially impact on patient stratification and monitoring of treatment response for image-guided treatment strategies.

  9. Fractionated stereotactic radiotherapy of glomus jugulare tumors. Local control, toxicity, symptomatology, and quality of life

    Henzel, M.; Gross, M.W.; Failing, T.; Strassmann, G.; Engenhart-Cabillic, R. [Marburg Univ. (Germany). Dept. of Radiation Oncology; Hamm, K.; Surber, G.; Kleinert, G. [HELIOS Klinikum Erfurt (Germany). Dept. of Stereotactic Neurosurgery and Radiosurgery; Sitter, H. [Marburg Univ. (Germany). Dept. of Theoretical Surgery

    2007-10-15

    Background and Purpose: For glomus jugulare tumors, the goal of treatment is microsurgical excision. To minimize postoperative neurologic deficits, stereotactic radiosurgery (SRS) was performed as an alternative treatment option. Stereotactic fractionated radiotherapy (SRT) could be a further alternative. This study aims at the assessment of local control, side effects, and quality of life (QoL). Patients and Methods: Between 1999-2005, 17 patients were treated with SRT. 11/17 underwent previous operations. 6/17 received primary SRT. Treatment was delivered by a linear accelerator with 6-MV photons. Median cumulative dose was 57.0 Gy. Local control, radiologic regression, toxicity, and symptomatology were evaluated half-yearly by clinical examination and MRI scans. QoL was assessed by Short Form-36 (SF-36). Results: Median follow-up was 40 months. Freedom from progression and overall survival for 5 years were 100% and 93.8%. Radiologic regression was seen in 5/16 cases, 11/16 patients were stable. Median tumor shrinkage was 17.9% (p = 0.14). Severe acute toxicity (grade 3-4) or any late toxicity was never seen. Main symptoms improved in 9/16 patients, 7/16 were stable. QoL was not affected in patients receiving primary SRT. Conclusion: SRT offers an additional treatment option of high efficacy with less side effects, especially in cases of large tumors, morbidity, or recurrences after incomplete resections. (orig.)

  10. Clinical Experience With Image-Guided Radiotherapy in an Accelerated Partial Breast Intensity-Modulated Radiotherapy Protocol

    Purpose: To explore the feasibility of fiducial markers for the use of image-guided radiotherapy (IGRT) in an accelerated partial breast intensity modulated radiotherapy protocol. Methods and Materials: Nineteen patients consented to an institutional review board approved protocol of accelerated partial breast intensity-modulated radiotherapy with fiducial marker placement and treatment with IGRT. Patients (1 patient with bilateral breast cancer; 20 total breasts) underwent ultrasound guided implantation of three 1.2- x 3-mm gold markers placed around the surgical cavity. For each patient, table shifts (inferior/superior, right/left lateral, and anterior/posterior) and minimum, maximum, mean error with standard deviation were recorded for each of the 10 BID treatments. The dose contribution of daily orthogonal films was also examined. Results: All IGRT patients underwent successful marker placement. In all, 200 IGRT treatment sessions were performed. The average vector displacement was 4 mm (range, 2-7 mm). The average superior/inferior shift was 2 mm (range, 0-5 mm), the average lateral shift was 2 mm (range, 1-4 mm), and the average anterior/posterior shift was 3 mm (range, 1 5 mm). Conclusions: This study shows that the use of IGRT can be successfully used in an accelerated partial breast intensity-modulated radiotherapy protocol. The authors believe that this technique has increased daily treatment accuracy and permitted reduction in the margin added to the clinical target volume to form the planning target volume.

  11. Alternating chemotherapy and hyperfractionated accelerated radiotherapy in non-metastatic inflammatory breast cancer; Radiotherapie hyperfractionnee acceleree alternee avec une chimiotherapie dans le cancer du sein inflammatoire non metastatique

    Hasbini, A.; Le Pechoux, C.; Roche, B.; Pignol, J.P.; Abdulkarim, B.; Habrand, J.L. [Institut Gustave Roussy, Dept. de Radiotherapie, 94 - Villejuif (France); Zelek, L.; Spielmann, M. [Institut Gustave Roussy, Dept. d' oncologie Medicale, 94 - Villejuif (France); Arriagada, R. [Instituto de Radiomedicina, IRAM, Santiago, (Chile); Guinebretiere, J.M. [Institut Gustave Roussy, Dept. d' Anatomopothologie, 94 - Villejuif (France); Tardivon, A. [Institut Gustave Roussy, Dept. de Radiodiagnostic, 94 - Villejuif (France)

    2000-08-01

    Based on encouraging results reported in alternating radiotherapy and chemotherapy in inflammatory breast carcinoma, we have tried in this study to optimize locoregional treatment with a hyperfractionated accelerated radiotherapy schedule alternating with chemotherapy. From May 1991 to May 1995, 54 patients, previously untreated, with non-metastatic inflammatory breast cancer were entered in an alternating protocol consisting of eight courses of combined chemotherapy and two series of loco-regional hyperfractionated accelerated radiotherapy with a total dose of 66 Gy. Hyperfractionated accelerated radiotherapy was started after three courses of neo-adjuvant chemotherapy (Adriamycin, Vincristine, Cyclophosphamide, Methotrexate, 5-fluoro-uracil) administered every 21 days {+-}G.CSF. The first series delivered 45 Gy/three weeks to the breast, the axillary, sub-clavicular and internal mammary nodes, with two daily sessions of 1.5 Gy separated by an interval of eight hours, the second series consisted of a boost (21 Gy/14 fractions/10d) alternating with another regimen of anthracycline-based-chemotherapy (a total of five cycles every three weeks). Hormonal treatment was given to all patients. Of the 53 patients evaluated at the end of the treatment, 44(83%) had a complete clinical response, seven (13%) had a partial response (>50%) and two (4%) had tumoral progression. Of the 51 patients who were locally controlled, 18 (35%) presented a locoregional recurrence (LRR); eight(15 %) had to undergo a mastectomy. All the patients but two LRR developed metastases or died of local progressive disease and 26 (50%) developed metastases. With a median follow-up of 39 months (range: 4-74 months), survival rates at three and five years were respectively, 66 and 45% for overall survival and 45 and 36% for disease-free survival. Alternating a combination of chemotherapy and hyperfractionated accelerated radiotherapy is a well-tolerated regimen which provides acceptable local control

  12. Toxicity and cosmetic outcome of three-dimensional conformal radiotherapy for accelerated partial breast irradiation

    Gatti, M.; Bresciani, S.; Ponzone, R.; Panaia, R.; Salatino, A.; Stasi, M.; Gabriele, P. [IRCC, Candiolo (Italy)

    2011-10-15

    Full text of publication follows: Purpose.- To analyse the incidence and severity of acute and late normal tissue toxicity and cosmetic outcome using three - dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. Patients and Methods.- 70 patients with stage I disease were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation, in an approved protocol. The prescribed dose was 34 Gy in all patients delivered in 10 fractions over 5 consecutive days. On all CT scans gross tumor volume (GTV ) was defined around surgical clips. A 1.5 cm margin was added in order to account for clinical target volume (CTV) . A margin of 1 cm was added to CTI to define the planning target volume (PTV). The dose-volume constraints were followed in accordance with the specifications as dictated in the NSABP/RTOG protocol. After treatment, patients underwent a clinical and cosmetic evaluation every 3 months. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed by the physicians using the controlateral untreated breast as the reference (Harvard scale). Results.- Median patient age was 66 years (range 51-80). Median follow-up was 15 months (range 6-46). Tumor size was < 10 mm in 33 patients (53%) and > 2 cm in 4(6%). The mean value of the ratio between the PTV and the whole ipsilateral breast volume was 38 % and the median percentage whole breast volume that received 95 % of prescribed dose was 34% (range 16%-55%). The rate of G1 and G2 acute skin toxicity was 28% and 2% respectively and the late toxicity was 17% (G1). G2 or greater toxicities were not observed. The most pronounced G1 late toxicity was subcutaneous fibrosis, developed in 3 patients. The cosmetic outcome was excellent in 83% and good in 17%. Conclusion.- Accelerated partial breast irradiation using three-dimensional conformal radiotherapy is technically feasible with very low acute and late toxicity. Long

  13. Correlation between egfr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

    Pedicini Piernicola

    2012-08-01

    Full Text Available Abstract Purpose To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr and the reduction of the effective doubling time (TD during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC. Methods A survey of the published papers comparing 3-years of local regional control rate (LCR for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of TD were obtained by a model incorporating the overall time corrected biologically effective dose (BED and a 3-year clinical LCR for high and low EGFr groups of patients (HEGFr and LEGFr, respectively. By obtaining the TD from the above analysis and the sub-sites’ potential doubling time (Tpot from flow cytometry and immunohistochemical methods, we were able to estimate the average TD for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (Dprolif, was estimated. Results The averages of TD were 77 (27-9095% days in LEGFr and 8.8 (7.3-11.095% days in HEGFr, if an onset of accelerated proliferation TK at day 21 was assumed. The correspondent HEGFr sub-sites’ TD were 5.9 (6.6, 5.9 (6.6, 4.6 (6.1, 14.3 (12.9 days, with respect to literature immunohistochemical (flow cytometry data of Tpot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The Dprolif for the HEGFr groups were 0.33 (0.29, 0.33 (0.29, 0.42 (0.31, 0.14 (0.15 Gy/day if α = 0.3 Gy-1 and α/β = 10 Gy were assumed. Conclusions A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced TD and Dprolif for each head and neck

  14. Correlation between egfr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

    To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr) and the reduction of the effective doubling time (TD) during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT) is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC). A survey of the published papers comparing 3-years of local regional control rate (LCR) for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of TD were obtained by a model incorporating the overall time corrected biologically effective dose (BED) and a 3-year clinical LCR for high and low EGFr groups of patients (HEGFr and LEGFr), respectively. By obtaining the TD from the above analysis and the sub-sites’ potential doubling time (Tpot) from flow cytometry and immunohistochemical methods, we were able to estimate the average TD for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (Dprolif), was estimated. The averages of TD were 77 (27-90)95% days in LEGFr and 8.8 (7.3-11.0)95% days in HEGFr, if an onset of accelerated proliferation TK at day 21 was assumed. The correspondent HEGFr sub-sites’ TD were 5.9 (6.6), 5.9 (6.6), 4.6 (6.1), 14.3 (12.9) days, with respect to literature immunohistochemical (flow cytometry) data of Tpot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The Dprolif for the HEGFr groups were 0.33 (0.29), 0.33 (0.29), 0.42 (0.31), 0.14 (0.15) Gy/day if α = 0.3 Gy-1 and α/β = 10 Gy were assumed. A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced TD and Dprolif for each head and neck sub-site

  15. Toxicity and cosmetic outcome of three-dimensional conformal radiotherapy for accelerated partial breast irradiation

    Full text of publication follows: Purpose.- To analyse the incidence and severity of acute and late normal tissue toxicity and cosmetic outcome using three - dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. Patients and Methods.- 70 patients with stage I disease were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation, in an approved protocol. The prescribed dose was 34 Gy in all patients delivered in 10 fractions over 5 consecutive days. On all CT scans gross tumor volume (GTV ) was defined around surgical clips. A 1.5 cm margin was added in order to account for clinical target volume (CTV) . A margin of 1 cm was added to CTI to define the planning target volume (PTV). The dose-volume constraints were followed in accordance with the specifications as dictated in the NSABP/RTOG protocol. After treatment, patients underwent a clinical and cosmetic evaluation every 3 months. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed by the physicians using the controlateral untreated breast as the reference (Harvard scale). Results.- Median patient age was 66 years (range 51-80). Median follow-up was 15 months (range 6-46). Tumor size was 2 cm in 4(6%). The mean value of the ratio between the PTV and the whole ipsilateral breast volume was 38 % and the median percentage whole breast volume that received 95 % of prescribed dose was 34% (range 16%-55%). The rate of G1 and G2 acute skin toxicity was 28% and 2% respectively and the late toxicity was 17% (G1). G2 or greater toxicities were not observed. The most pronounced G1 late toxicity was subcutaneous fibrosis, developed in 3 patients. The cosmetic outcome was excellent in 83% and good in 17%. Conclusion.- Accelerated partial breast irradiation using three-dimensional conformal radiotherapy is technically feasible with very low acute and late toxicity. Long-term results are needed to assess

  16. Feasibility and early results of accelerated radiotherapy for head and neck carcinoma in the elderly

    Allal, Abdelkarim Said; Maire, Daphne Isabel; Becker, Minerva; Dulguerov, Pavel

    2000-01-01

    Accelerated radiotherapy (RT) represents a promising method with which to improve the treatment outcome in patients with head and neck carcinoma. However, its applicability to elderly patients has not been well established. This study assessed treatment toxicities, patient compliance, and oncologic results in patients age >/= 70 years who were treated with an accelerated concomitant boost RT schedule.

  17. A proliferation saturation index to predict radiation response and personalize radiotherapy fractionation

    Prokopiou, Sotiris; Eduardo G Moros; Poleszczuk, Jan; Caudell, Jimmy; Torres-Roca, Javier F.; Latifi, Kujtim; Lee, Jae K.; Myerson, Robert; Harrison, Louis B.; Enderling, Heiko

    2015-01-01

    Background Although altered protocols that challenge conventional radiation fractionation have been tested in prospective clinical trials, we still have limited understanding of how to select the most appropriate fractionation schedule for individual patients. Currently, the prescription of definitive radiotherapy is based on the primary site and stage, without regard to patient-specific tumor or host factors that may influence outcome. We hypothesize that the proportion of radiosensitive pro...

  18. Short-Course Accelerated Radiotherapy in Palliative Treatment of Advanced Pelvic Malignancies: A Phase I Study

    Caravatta, Luciana [Department of Radiation Oncology, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Padula, Gilbert D.A. [Department of Radiation Oncology, Lacks Cancer Center Saint Mary' s Health Care, Grand Rapids, MI (United States); Macchia, Gabriella, E-mail: gmacchia@rm.unicatt.it [Department of Radiation Oncology, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Ferrandina, Gabriella [Department of Gynecologic Oncology, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Bonomo, Pierluigi; Deodato, Francesco; Massaccesi, Mariangela [Department of Radiation Oncology, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Mignogna, Samantha; Tambaro, Rosa [Department of Palliative Therapies, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Rossi, Marco [Department of Anaesthesia, Intensive Care, and Pain Medicine, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Flocco, Mariano [' Madre Teresa di Calcutta' Hospice, Larino (Italy); Scapati, Andrea [Department of Radiation Oncology, ' San Francesco' Hospital, Nuoro (Italy); and others

    2012-08-01

    Purpose: To define the maximum tolerated dose of a conformal short-course accelerated radiotherapy in patients with symptomatic advanced pelvic cancer. Methods and Materials: A phase I trial in 3 dose-escalation steps was designed: 14 Gy (3.5-Gy fractions), 16 Gy (4-Gy fractions), and 18 Gy (4.5-Gy fractions). The eligibility criteria included locally advanced and/or metastatic pelvic cancer and Eastern Cooperative Oncology Group performance status of {<=}3. Treatment was delivered in 2 days with twice-daily fractionation and at least an 8-hour interval. Patients were treated in cohorts of 6-12 to define the maximum tolerated dose. The dose-limiting toxicity was defined as any acute toxicity of grade 3 or greater, using the Radiation Therapy Oncology Group scale. Pain was recorded using a visual analog scale. The effect on quality of life was evaluated according to Cancer Linear Analog Scale (CLAS). Results: Of the 27 enrolled patients, 11 were male and 16 were female, with a median age of 72 years (range 47-86). The primary tumor sites were gynecologic (48%), colorectal (33.5%), and genitourinary (18.5%). The most frequent baseline symptoms were bleeding (48%) and pain (33%). Only grade 1-2 acute toxicities were recorded. No patients experienced dose-limiting toxicity. With a median follow-up time of 6 months (range 3-28), no late toxicities were observed. The overall (complete plus partial) symptom remission was 88.9% (95% confidence interval 66.0%-97.8%). Five patients (41.7%) had complete pain relief, and six (50%) showed >30% visual analog scale reduction. The overall response rate for pain was 91.67% (95% confidence interval 52.4%-99.9%). Conclusions: Conformal short course radiotherapy in twice-daily fractions for 2 consecutive days was well tolerated up to a total dose of 18 Gy. A phase II study is ongoing to confirm the efficacy on symptom control and quality of life indexes.

  19. Short-Course Accelerated Radiotherapy in Palliative Treatment of Advanced Pelvic Malignancies: A Phase I Study

    Purpose: To define the maximum tolerated dose of a conformal short-course accelerated radiotherapy in patients with symptomatic advanced pelvic cancer. Methods and Materials: A phase I trial in 3 dose-escalation steps was designed: 14 Gy (3.5-Gy fractions), 16 Gy (4-Gy fractions), and 18 Gy (4.5-Gy fractions). The eligibility criteria included locally advanced and/or metastatic pelvic cancer and Eastern Cooperative Oncology Group performance status of ≤3. Treatment was delivered in 2 days with twice-daily fractionation and at least an 8-hour interval. Patients were treated in cohorts of 6-12 to define the maximum tolerated dose. The dose-limiting toxicity was defined as any acute toxicity of grade 3 or greater, using the Radiation Therapy Oncology Group scale. Pain was recorded using a visual analog scale. The effect on quality of life was evaluated according to Cancer Linear Analog Scale (CLAS). Results: Of the 27 enrolled patients, 11 were male and 16 were female, with a median age of 72 years (range 47-86). The primary tumor sites were gynecologic (48%), colorectal (33.5%), and genitourinary (18.5%). The most frequent baseline symptoms were bleeding (48%) and pain (33%). Only grade 1-2 acute toxicities were recorded. No patients experienced dose-limiting toxicity. With a median follow-up time of 6 months (range 3-28), no late toxicities were observed. The overall (complete plus partial) symptom remission was 88.9% (95% confidence interval 66.0%-97.8%). Five patients (41.7%) had complete pain relief, and six (50%) showed >30% visual analog scale reduction. The overall response rate for pain was 91.67% (95% confidence interval 52.4%-99.9%). Conclusions: Conformal short course radiotherapy in twice-daily fractions for 2 consecutive days was well tolerated up to a total dose of 18 Gy. A phase II study is ongoing to confirm the efficacy on symptom control and quality of life indexes.

  20. Small-field fractionated radiotherapy with or without stereotactic boost for vestibular schwannoma

    Purpose: To assess the efficacy and toxicity of small-field fractionated radiotherapy with or without stereotactic boost (SB) for vestibular schwannomas.Methods and materials: Thirty-nine patients with vestibular schwannoma were treated with irradiation between March 1991 and February 1996. Extra-meatal tumor diameters were under 30 mm. Thirty-three patients received small-field fractionated radiotherapy followed by SB. Basic dose schedule was 44 Gy in 22 fractions over 5 1/2 weeks plus 4 Gy in one session. Six patients received small-field fractionated radiotherapy only (40-44 Gy in 20-22 fractions over 5-5 1/2 weeks or 36 Gy in 20 fractions over 5 weeks).< Results: Follow-up ranged from 6 to 69 months (median, 24 months). Tumors decreased in size in 13 cases (33%), were unchanged in 25 (64%), and increased in one (3%). The actuarial 2-year tumor control rate was 97%. Fifteen patients had useful hearing (Gardner-Robertson class 1-2) and 25 patients had testable hearing (class 1-4) before irradiation. The 2-year actuarial rates of useful hearing preservation (free of deterioration from class 1-2 to class 3-5) were 78%. The 2-year actuarial rates of any testable hearing preservation (free of deterioration from class 1-4 to class 5) were 96%. No permanent facial and trigeminal neuropathy developed after irradiation. The 2-year actuarial incidences of facial and trigeminal neuropathies were 8% and 16%, respectively.Conclusions: Small-field fractionated radiotherapy with or without SB provides excellent short-term local control and a relatively low incidence of complications for vestibular schwannoma, although further follow-up is necessary to evaluate the long-term results. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  1. Accelerated Partial Breast Irradiation with Intensity-Modulated Radiotherapy Is Feasible for Chinese Breast Cancer Patients

    He, Zhenyu; Wu, Sangang; Zhou, Juan; Li, Fengyan; Sun, Jiayan; Lin, Qin; Lin, Huanxin; Guan, Xunxing

    2014-01-01

    Purpose Several accelerated partial breast irradiation (APBI) techniques are being investigated in patients with early-stage breast cancer. The present study evaluated the feasibility, early toxicity, initial efficacy, and cosmetic outcomes of accelerated partial breast intensity-modulated radiotherapy (IMRT) for Chinese female patients with early-stage breast cancer after breast-conserving surgery. Methods A total of 38 patients met the inclusion criteria and an accelerated partial breast in...

  2. Effect of patient variation on standard- and hypo-fractionated radiotherapy of prostate cancer

    Xiong, W; Li, J; Ma, C-M [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111 (United States)

    2005-04-07

    Recent publications suggested that the {alpha}/{beta} ratio in the well-known linear quadratic (LQ) model could be as low as 1.5 Gy for prostate cancer, indicating that prostate cancer control might be very sensitive to changes in the dose fractionation scheme. This also suggests that the standard-fractionation scheme based on large {alpha}/{beta} ratios may not be optimal for the radio-therapeutic management of prostate cancer. Hypo-fractionated radiotherapy for prostate cancer has received more attention recently as an alternative treatment strategy, which may lead to reduced treatment time and cost. However, hypo-fractionated radiotherapy may be more sensitive to patient variation in terms of disease control than standard-fractionated radiotherapy. The variation of LQ parameters {alpha} and {beta} for a patient population may compromise the outcome of the treatment. This effect can be studied by the introduction of the {sigma}{sub {alpha}} and {sigma}{sub {beta}} parameters, which are the standard deviations of Gaussian distributions around {alpha}{sub 0} and {beta}{sub 0}. The purpose of this study is to examine the effect of patient variation in {alpha} and {beta} on tumour control probability for standard- and hypo-fractionated radiotherapy of prostate cancer. The tumour control probability based on the LQ model is calculated using parameters {alpha}, {beta}, {sigma}{sub {alpha}} and {sigma}{sub {beta}}. Our results show that {sigma}{sub {alpha}} is an important parameter for radiotherapy fractionation, independent of the {alpha}/{beta} ratio. A large {sigma}{sub {alpha}} will result in a significant increase in the radiation dose required to achieve the same 95% TCP. Compared with the standard-fractionated scheme, {sigma}{sub {alpha}} has a smaller effect on hypo-fractionated treatment at lower {alpha}/{beta} ratios. On the other hand, for lower {alpha}/{beta} ratios, the {beta} term also plays a more important role in cell-killing and therefore the patient

  3. Effect of patient variation on standard- and hypo-fractionated radiotherapy of prostate cancer

    Recent publications suggested that the α/β ratio in the well-known linear quadratic (LQ) model could be as low as 1.5 Gy for prostate cancer, indicating that prostate cancer control might be very sensitive to changes in the dose fractionation scheme. This also suggests that the standard-fractionation scheme based on large α/β ratios may not be optimal for the radio-therapeutic management of prostate cancer. Hypo-fractionated radiotherapy for prostate cancer has received more attention recently as an alternative treatment strategy, which may lead to reduced treatment time and cost. However, hypo-fractionated radiotherapy may be more sensitive to patient variation in terms of disease control than standard-fractionated radiotherapy. The variation of LQ parameters α and β for a patient population may compromise the outcome of the treatment. This effect can be studied by the introduction of the σα and σβ parameters, which are the standard deviations of Gaussian distributions around α0 and β0. The purpose of this study is to examine the effect of patient variation in α and β on tumour control probability for standard- and hypo-fractionated radiotherapy of prostate cancer. The tumour control probability based on the LQ model is calculated using parameters α, β, σα and σβ. Our results show that σα is an important parameter for radiotherapy fractionation, independent of the α/ ratio. A large σα will result in a significant increase in the radiation dose required to achieve the same 95% TCP. Compared with the standard-fractionated scheme, σα has a smaller effect on hypo-fractionated treatment at lower α/β ratios. On the other hand, for lower α/β ratios, the β term also plays a more important role in cell-killing and therefore the patient variation parameter σβ must be considered when designing a new dose fractionation scheme

  4. Avoidance of treatment interruption: an unrecognized benefit of accelerated radiotherapy in oropharyngeal carcinomas?

    Purpose: To assess the impact of treatment interruption on the potential gain in locoregional control obtained with accelerated radiotherapy (RT) compared with conventionally fractionated RT in patients with oropharyngeal carcinomas. Methods and Materials: 152 patients treated with radical RT for oropharyngeal carcinomas between 1979 and 1996 were retrospectively analyzed. According to the American Joint Committee on Cancer (AJCC) staging system, there were 6/30/43/73 stages I/II/III/IV. Sixty-one patients were treated with a conventional RT schedule (median dose 70 Gy in 35 fractions), and 91 patients with either of two 5/5.5-week accelerated RT schedules (median dose 69.6-69.9 Gy in 41 fractions). Discounting weekends, RT was interrupted for 2 consecutive days or more in 53 patients (median duration 11 days, range 2-97), including 67% of the patients in the conventional RT group and 13% in the accelerated RT group. Median follow-up for surviving patients was 55 months (range 23-230). The Cox proportional hazards model was used for the multivariate analysis of factors influencing locoregional control. Results: In univariate analysis, factors associated with a significant decrease in locoregional control included WHO performance status ≥1, advanced AJCC stages (III and IV), conventional RT fractionation, overall treatment time ≥44 days (median), and RT interruption. In the multivariate analysis, when introduced into the model individually, the three significant therapeutic factors remained significant after adjustment for the forced clinical variables. However, when the three therapeutic factors were introduced together into the model, beside the AJCC stage (P = 0.017), only RT interruption remained a significant independent adverse prognostic factor (P = 0.026). Conclusions: This multivariate analysis highlights the potential negative impact of treatment gaps on locoregional control in oropharyngeal carcinomas. This suggests that treatment interruption may be

  5. Comparison between observation policy and fractionated stereotactic radiotherapy (SRT) as an initial management for vestibular schwannoma

    Purpose: To compare the use of an observation policy with that of stereotactic radiotherapy (SRT) for treatment of vestibular schwannoma. Methods and Materials: The study group consisted of 27 patients who underwent observation as an initial treatment (observation group) and 50 who received SRT (SRT group). The mean follow-up period was 35 months and 31 months, respectively. Stereotactic radiotherapy consisted of small-field fractionated radiotherapy (36-44 Gy in 20-22 fractions over 6 weeks) with or without a subsequent 4-Gy single irradiation boost. Results: Actuarial tumor control rate of the SRT group was significantly better than that of the observation group (p < 0.0001). The mean growth was 3.87 mm/year in the observation group and -0.75 mm/year in the SRT group (p < 0.0001). Eleven patients (41%) in the observation group and 1 (2%) in the SRT group received salvage therapy (p < 0.001). There was no difference in the actuarial Gardner and Robertson's class preservation curves for 5 years after the initial presentation. Conclusion: Stereotactic radiotherapy using a fractionated schedule provides a better tumor control rate and a similar rate of deterioration for hearing levels compared to an observation policy. Initial SRT may be a reasonable alternative to a wait-and-see policy

  6. Single fraction versus multiple fraction radiotherapy for palliation of painful vertebral bone metastases: A prospective study

    Dipanjan Majumder

    2012-01-01

    Conclusions: Different fractionation of radiation has same response and toxicity in treatment of vertebral bone metastasis. Single fraction RT may be safely used to treat these cases as this is more cost effective and less time consuming. Studies may be conducted to find out particular subgroup of patients to be benefitted more by either fractionation schedule; however, our study cannot comment on that issue.

  7. Prescription dose and fractionation predict improved survival after stereotactic radiotherapy for brainstem metastases

    Leeman Jonathan E

    2012-07-01

    Full Text Available Abstract Background Brainstem metastases represent an uncommon clinical presentation that is associated with a poor prognosis. Treatment options are limited given the unacceptable risks associated with surgical resection in this location. However, without local control, symptoms including progressive cranial nerve dysfunction are frequently observed. The objective of this study was to determine the outcomes associated with linear accelerator-based stereotactic radiotherapy or radiosurgery (SRT/SRS of brainstem metastases. Methods We retrospectively reviewed 38 tumors in 36 patients treated with SRT/SRS between February 2003 and December 2011. Treatment was delivered with the Cyberknife™ or Trilogy™ radiosurgical systems. The median age of patients was 62 (range: 28–89. Primary pathologies included 14 lung, 7 breast, 4 colon and 11 others. Sixteen patients (44% had received whole brain radiation therapy (WBRT prior to SRT/SRS; ten had received prior SRT/SRS at a different site (28%. The median tumor volume was 0.94 cm3 (range: 0.01-4.2 with a median prescription dose of 17 Gy (range: 12–24 delivered in 1–5 fractions. Results Median follow-up for the cohort was 3.2 months (range: 0.4-20.6. Nineteen patients (52% had an MRI follow-up available for review. Of these, one patient experienced local failure corresponding to an actuarial 6-month local control of 93%. Fifteen of the patients with available follow-up imaging (79% experienced intracranial failure outside of the treatment volume. The median time to distant intracranial failure was 2.1 months. Six of the 15 patients with distant intracranial failure (40% had received previous WBRT. The actuarial overall survival rates at 6- and 12-months were 27% and 8%, respectively. Predictors of survival included Graded Prognostic Assessment (GPA score, greater number of treatment fractions, and higher prescription dose. Three patients experienced acute treatment-related toxicity consisting of

  8. IAEA-HypoX. A randomized multicenter study of the hypoxic radiosensitizer nimorazole concomitant with accelerated radiotherapy in head and neck squamous cell carcinoma

    Metwally, Mohamed Ahmed Hassan; Ali, Rubina; Kuddu, Maire;

    2015-01-01

    multicenter randomized trial in patients with HNSCC. Tumors were treated to a dose of 66-70Gy, 33-35 fractions, 6 fractions per week. NIM was administered in a dose of 1.2gperm(2), 90min before the first daily RT fraction. The primary endpoint was loco-regional failure. The trial was closed prematurely by......PURPOSE: To test the hypothesis that radiotherapy (RT) of head and neck squamous cell carcinoma (HNSCC) can be improved by hypoxic modification using nimorazole (NIM) in association with accelerated fractionation. MATERIALS AND METHODS: The protocol was activated in March 2012 as an international...... HNSCC given the hypoxic modifier NIM in addition to accelerated fractionation RT. However, the trial also revealed that conducting multicenter and multinational study combining drug and RT in developing countries may suffer from uncontrolled and unsolvable problems....

  9. Adjuvant single-fraction radiotherapy is safe and effective for intractable keloids

    The aim of this study was to assess the feasibility and efficacy of high-dose, single-fraction electron beam radiotherapy for therapy-resistant keloids. Before 2010, intractable keloids were treated at our institution with post-operative irradiation of 6-15 Gy in 3-5 fractionations. For convenience and cost effectiveness, we have changed our treatment protocol to high-dose single-fraction radiotherapy. A total of 12 patients with 16 keloid lesions were treated from January 2010 to January 2013 in our department. A 10-Gy dose of electron irradiation was given within 72 h of the surgical excision. The mean follow-up period was 20 months. Treatments were well tolerated, and there was no recurrence in any of the patients. Severe adverse effects were not observed. Surgical excision of the keloid, followed by immediate, single-fraction, high-dose radiotherapy, is both safe and effective in preventing recurrence of therapy-resistant keloids. (author)

  10. Intensity Modulated Radiotherapy (IMRT and Fractionated Stereotactic Radiotherapy (FSRT for children with head-and-neck-rhabdomyosarcoma

    Huber Peter E

    2007-09-01

    Full Text Available Abstract Background The present study evaluates the outcome of 19 children with rhabdomyosarcoma of the head-and-neck region treated with Intensity Modulated Radiotherapy (IMRT or Fractionated Stereotactic Radiotherapy (FSRT between August 1995 and November 2005. Methods We treated 19 children with head-and-neck rhabdomyosarcoma with FSRT (n = 14 or IMRT (n = 5 as a part of multimodal therapy. Median age at the time of radiation therapy was 5 years (range 2–15 years. All children received systemic chemotherapy according to the German Soft Tissue Sarcoma Study protocols. Median size of treatment volume for RT was 93,4 ml. We applied a median total dose of 45 Gy (range 32 Gy – 54 Gy using a median fractionation of 5 × 1,8 Gy/week (range 1,6 Gy – 1,8 Gy. The median time interval between primary diagnosis and radiation therapy was 5 months (range 3–9 months. Results After RT, the 3- and 5-year survival rate was 94%. The 3- and 5-year actuarial local control rate after RT was 89%. The actuarial freedom of distant metastases rate at 3- and 5-years was 89% for all patients. Radiotherapy was well tolerated in all children and could be completed without interruptions > 4 days. No toxicities >CTC grade 2 were observed. The median follow-up time after RT was 17 months. Conclusion IMRT and FSRT lead to excellent outcome in children with head-and-neck RMS with a low incidence of treatment-related side effects.

  11. Prescription dose and fractionation predict improved survival after stereotactic radiotherapy for brainstem metastases

    Leeman Jonathan E; Clump David A; Wegner Rodney E; Heron Dwight E; Burton Steven A; Mintz Arlan H

    2012-01-01

    Abstract Background Brainstem metastases represent an uncommon clinical presentation that is associated with a poor prognosis. Treatment options are limited given the unacceptable risks associated with surgical resection in this location. However, without local control, symptoms including progressive cranial nerve dysfunction are frequently observed. The objective of this study was to determine the outcomes associated with linear accelerator-based stereotactic radiotherapy or radiosurgery (SR...

  12. Accelerated split-course radiotherapy and concomitant cis-platinum and 5-fluorouracil chemotherapy with folinic acid enhancement in unresectable head and neck cancer

    In patients suffering from locally advanced, unresectable squamous cell carcinoma (SCC) of the base of the tongue, the floor of the mouth, the mobile part of the tongue, the tonsils, the hypopharynx and the larynx radiotherapy yields poor results, due to local failure rather than to distant metastases. Since toxicity of radiotherapy and cytotoxic chemotherapy do not overlap entirely efforts were made to achieve better results combining these two treatment modalities. Clinical trials on simultaneous radiotherapy/chemotherapy focussed on two cytotoxic agents: Cis-dichlorodiammineplatinum(II) (cis-DDP) and 5-flourouracil (5-FU). Another approach to overcome the radioresistance of large SCC adopts accelerated fractionation. The potential tumor doubling time of sqamous cell carcinomas is about four days, and thus repopulation of surviving clonogenic tumor cells during fractionated radiotherapy may be the cause of poor treatment results. In this pilot study a twice daily fractionated split-course radiotherapy is combined with simultaneous administration of cis-DDP and 5-FU with folinic acid (FA) enhancement. (orig.)

  13. Accelerated split-course radiotherapy and concomitant cis-platinum and 5-fluorouracil chemotherapy with folinic acid enhancement in unresectable head and neck cancer

    Wendt, T.G.; Wustrow, T.P.U.; Hartenstein, R.C.; Trott, K.R.

    1988-01-01

    In patients suffering from locally advanced, unresectable squamous cell carcinoma (SCC) of the base of the tongue, the floor of the mouth, the mobile part of the tongue, the tonsils, the hypopharynx and the larynx radiotherapy yields poor results, due to local failure rather than to distant metastases. Since toxicity of radiotherapy and cytotoxic chemotherapy do not overlap entirely efforts were made to achieve better results combining these two treatment modalities. Clinical trials on simultaneous radiotherapy/chemotherapy focussed on two cytotoxic agents: Cis-dichlorodiammineplatinum(II) (cis-DDP) and 5-flourouracil (5-FU). Another approach to overcome the radioresistance of large SCC adopts accelerated fractionation. The potential tumor doubling time of sqamous cell carcinomas is about four days, and thus repopulation of surviving clonogenic tumor cells during fractionated radiotherapy may be the cause of poor treatment results. In this pilot study a twice daily fractionated split-course radiotherapy is combined with simultaneous administration of cis-DDP and 5-FU with folinic acid (FA) enhancement.

  14. Prolonged survival when temozolomide is added to accelerated radiotherapy for glioblastoma multiforme

    The goal of this study was to evaluate accelerated radiotherapy with and without temozolomide (TMZ) for glioblastoma multiforme (GBM). This retrospective analysis evaluated 86 patients with histologically proven GBM who were treated with accelerated radiotherapy of 1.8 Gy twice daily to a total dose of 54 Gy within 3 weeks. Median age was 62 years and median Karnofsky index was 90. A total of 41 patients received radiotherapy only from 2002-2005 and 45 patients were treated with TMZ concomitantly and after radiotherapy from 2005-2007. Median overall survival (OS) was 12.5 months and 2-year OS was 15.4%. Patient characteristics were well balanced between the two groups except for better performance status (p = 0.05) and higher frequency of retreatment for the first recurrence (p = 0.02) in the TMZ group. Age at diagnosis (HR 2.83) and treatment with TMZ (HR 0.60) were correlated with OS in the multivariate analysis: treatment with and without TMZ resulted in median OS of 16 months and 11.3 months, respectively. Hematological toxicity grade > II was observed in 2/45 patients and 5/37 patients during simultaneous radiochemotherapy and adjuvant TMZ. TMZ added to accelerated radiotherapy for GBM resulted in prolonged overall survival with low rates of severe hematological toxicity. (orig.)

  15. Biological dose representation for carbon-ion radiotherapy of unconventional fractionation

    Kanematsu, Nobuyuki; Inaniwa, Taku

    2016-01-01

    In carbon-ion radiotherapy, single-beam delivery each day in alternate directions has been commonly practiced for operational efficiency, taking advantage of the Bragg peak and the relative biological effectiveness (RBE) for uniform dose conformation to a tumor. The treatment plans are usually evaluated with total RBE-weighted dose, which is however deficient in relevance to the biological effect in the linear-quadratic model due to its quadratic-dose term, or the dose-fractionation effect. I...

  16. The treatment of a large acoustic tumor with fractionated stereotactic radiotherapy

    McClelland, Shearwood; Gerbi, Bruce J.; Cho, Kwan H.; Hall, Walter A.

    2007-01-01

    The treatment of acoustic neuromas (AN) usually involves surgical excision or stereotactic radiosurgery. However, for large AN (mean diameter > 3 cm), stereotactic radiosurgery is rarely used, leaving patients with limited noninvasive treatment options. Recently, the use of fractionated stereotactic radiotherapy (FSRT) has been effective in treating small to medium-sized AN. We present a patient with a large AN treated with FSRT. The patient was a 43-year-old man presenting with imbalance, ti...

  17. A proliferation saturation index to predict radiation response and personalize radiotherapy fractionation

    Although altered protocols that challenge conventional radiation fractionation have been tested in prospective clinical trials, we still have limited understanding of how to select the most appropriate fractionation schedule for individual patients. Currently, the prescription of definitive radiotherapy is based on the primary site and stage, without regard to patient-specific tumor or host factors that may influence outcome. We hypothesize that the proportion of radiosensitive proliferating cells is dependent on the saturation of the tumor carrying capacity. This may serve as a prognostic factor for personalized radiotherapy (RT) fractionation. We introduce a proliferation saturation index (PSI), which is defined as the ratio of tumor volume to the host-influenced tumor carrying capacity. Carrying capacity is as a conceptual measure of the maximum volume that can be supported by the current tumor environment including oxygen and nutrient availability, immune surveillance and acidity. PSI is estimated from two temporally separated routine pre-radiotherapy computed tomography scans and a deterministic logistic tumor growth model. We introduce the patient-specific pre-treatment PSI into a model of tumor growth and radiotherapy response, and fit the model to retrospective data of four non-small cell lung cancer patients treated exclusively with standard fractionation. We then simulate both a clinical trial hyperfractionation protocol and daily fractionations, with equal biologically effective dose, to compare tumor volume reduction as a function of pretreatment PSI. With tumor doubling time and radiosensitivity assumed constant across patients, a patient-specific pretreatment PSI is sufficient to fit individual patient response data (R2 = 0.98). PSI varies greatly between patients (coefficient of variation >128 %) and correlates inversely with radiotherapy response. For this study, our simulations suggest that only patients with intermediate PSI (0.45–0.9) are

  18. Evolution of Hypofractionated Accelerated Radiotherapy for Prostate Cancer – The Sunnybrook Experience

    Hima Bindu Musunuru

    2014-11-01

    Full Text Available Stereotactic Ablative Body Radiotherapy (SABR is a newer method of ultra hypo fractionated radiotherapy that uses combination of image guided radiotherapy (IGRT and intensity modulated radiotherapy(IMRT or volumetric modulated arc therapy(VMAT, to deliver high doses of radiation in a few fractions to a target, at the same time sparing the surrounding organs at risk(OAR.SABR is ideal for treating small volumes of disease and has been introduced in a number of disease sites including brain, lung, liver, spine and prostate. Given the radiobiological advantages of treating prostate cancer with high doses per fraction, SABR is becoming a standard of care for low and intermediate risk prostate cancer patients based upon the results from Sunny Brook and also the US-based prostate SABR consortium. This review examines the development of moderate and ultra hypo fractionation schedules at the Odette Cancer centre, Sunnybrook Health Sciences. Moderate hypo fractionation protocol was first developed in 2001 for intermediate risk prostate cancer and from there on different treatment schedules including SABR evolved for all risk groups.

  19. PhoNeS: A novel approach to BNCT with conventional radiotherapy accelerators

    PhoNeS (Photo Neutron Source) is an INFN project devoted to the optimization of the neutron production and moderation in radiotherapy linear accelerators. LinAcs producing high energy (15-25MeV) photon beams are becoming widespread. At this energy neutron photo-production is unavoidable and the neutron dose must be controlled and reduced during normal radiotherapy. A technique known as BNCT (Boron Neutron Capture Therapy) uses neutrons for radiotherapic treatments: the cells are given a drug containing B10 which undergoes fission after neutron capture, inducing heavy damages to the DNA of the cell itself. This paper will describe the moderator developed by PhoNeS and the results in terms of neutron flux and spectrum and photon contamination of the measurements performed on several radiotherapy accelerators

  20. A retrospective analysis of survival outcomes for two different radiotherapy fractionation schedules given in the same overall time for limited stage small cell lung cancer

    To compare survival outcomes for two fractionation schedules of thoracic radiotherapy, both given over 3 weeks, in patients with limited stage small cell lung cancer (LS-SCLC). At Radiation Oncology Mater Centre (ROMC) and the Royal Brisbane and Women's Hospital (RBWH), patients with LS-SCLC treated with curative intent are given radiotherapy (with concurrent chemotherapy) to a dose of either 40Gy in 15 fractions ('the 40Gy/15⧣group') or 45Gy in 30 fractions ('the 45Gy/30⧣group'). The choice largely depends on institutional preference. Both these schedules are given over 3 weeks, using daily and twice-daily fractionation respectively. The records of all such patients treated from January 2000 to July 2009 were retrospectively reviewed and survival outcomes between the two groups compared. Of 118 eligible patients, there were 38 patients in the 40Gy/15⧣ group and 41 patients in the 45Gy/30⧣ group. The median relapse-free survival time was 12 months in both groups. Median overall survival was 21 months (95% CI 2–37 months) in the 40Gy/15⧣ group and 26 months (95% CI 1–48 months) in the 45Gy/30⧣ group. The 5-year overall survival rates were 20% and 25%, respectively (P=0.24). On multivariate analysis, factors influencing overall survival were: whether prophylactic cranial irradiation (PCI) was given (P=0.01) and whether salvage chemotherapy was given at the time of relapse (P=0.057). Given the small sample size, the potential for selection bias and the retrospective nature of our study it is not possible to draw firm conclusions regarding the efficacy of hypofractionated thoracic radiotherapy compared with hyperfractionated accelerated thoracic radiotherapy however hypofractionated radiotherapy may result in equivalent relapse-free survival.

  1. Late course accelerated hyperfractionation radiotherapy for elderly patients with esophageal carcinoma

    Objective: To study the clinical results and prognostic factors of late course accelerated hyperfractionation radiotherapy (LCAHR) in the treatment of esophageal carcinoma in the elderly. Methods: 105 over 60 year-old patients with esophageal carcinoma who received radical LCAHR, were retrospectively analysed. Radical tumoricidal dose of 67.9-72.0 Gy was delivered in 39-43 fractions over 42-53 days. Results: The 5-year local control rate was 63.7%. The 5-year disease-free survival and overall survival rate were 22.6% and 34.4%. Acute esophagitis and bronchitis were the most common but acceptable radioreactions Grade 1-2. No significant differences were found either in the clinical response or complication, between the 60-69 year and 70-80 year groups. By multivariate analysis, T stage and KPS score were two independent prognostic factors. Of 67 death cases, 31 died of local relapse, 23 of distant metastases, 8 of both and 5 of other causes. Conclusions: LCAHR toxicity, being tolerable for the older esophageal carcinoma patients, may improve their survival and quality of life

  2. Radiobiological characterization of different energy-photon beams used in radiotherapy from linear accelerator

    The main objective of this study was to perform a radiobiological characterization of different energy photon beams (6 MV and 15 MV) from linear accelerator used in radiotherapy, and comparison of different treatment modalities, with special regard to late effects of radiation. Using two end points, cell survival and micronucleus induction, in the biological system (Chines hamster V79 cell line). Chromosomes number was counted and found to be 22 chromosomes per cell. Cells were kept in confluent growth for two days and then exposed to two photon beams and immediately after irradiation were counted and re seeded in different numbered for each dose. For evaluation of surviving fraction samples were incubated at 37oC for 6 days, five samples were counted for each dose. At the same time three samples were seeded for the micronuclei frequency and incubated at 37oC after 24 hours cytochalasin-B was added to block cells in cytokinesis. The survival curve showed similar curves for the two beams and decreased with dose. The micronuclei frequency was positively correlated with dose and the energy of the photon. This indicates the presence of low dose of photoneutrons produced by using high energy photon beams. (Author)

  3. Long term results of hypo-fractionated mammary radiotherapy as exclusive treatment of elderly patients suffering from a beast cancer

    The author discuss the results obtained on 29 elderly patients exclusively treated between 1995 and 1999 by mammary irradiation (32.5 Gy) in 5 fractions over 5 weeks, and then with a lower additional irradiation (13 Gy) in two fractions. They discuss the efficiency of this hypo-fractionated radiotherapy without breast conserving surgery. Short communication

  4. Carbon Ion Radiotherapy in Advanced Hypofractionated Regimens for Prostate Cancer: From 20 to 16 Fractions

    Okada, Tohru [National Institute of Radiological Sciences, Chiba (Japan); Tsuji, Hiroshi, E-mail: h_tsuji@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Kamada, Tadashi [National Institute of Radiological Sciences, Chiba (Japan); Akakura, Koichiro; Suzuki, Hiroyoshi; Shimazaki, Jun [Department of Urology, Graduate School of Medicine, Chiba University, Chiba (Japan); Tsujii, Hirohiko [National Institute of Radiological Sciences, Chiba (Japan)

    2012-11-15

    Purpose: To assess the effects of differences in dose fractionation on late radiation toxicity and biochemical control in patients with prostate cancer treated with carbon ion radiotherapy (C-ion RT). Methods and Materials: A total of 740 prostate cancer patients who received C-ion RT between April 2000 and February 2009 were analyzed. Of those, 664 patients followed for at least 1 year were analyzed with regard to late radiation toxicity. Biochemical relapse-free (BRF) and overall survival (OS) rates in patient subgroups with each dose-fractionation were analyzed. Results: Only 1 case of grade 3 genitourinary (GU) morbidity was observed in 20 fractions, and none of the patients developed higher grade morbidities. The incidence of late GU toxicity in patients treated with 16 fractions was lower than that of patients treated with 20 fractions. The OS rate and BRF rate of the entire group at 5 years were 95.2% and 89.7%, respectively. The 5-year BRF rate of the patients treated with 16 fractions of C-ion RT (88.5%) was comparable to that of the patients treated with 20 fractions (90.2%). Conclusion: C-ion RT of 57.6 GyE (the physical C-ion dose [Gy] Multiplication-Sign RBE) in 16 fractions could offer an even lower incidence of genitourinary toxicity and comparable BRF rate than that in 20 fractions. Advancement in hypofractionation could be safely achieved with C-ion RT for prostate cancer.

  5. Optimization of combination therapy of arsenic trioxide and fractionated radiotherapy for malignant glioma

    Purpose: The primary objective was to optimize the combined treatment regimen using arsenic trioxide (ATO) and fractionated radiotherapy for the treatment of malignant glioma. Methods and Materials: Nude mice with human glioma xenograft tumors were treated with fractionated local tumor radiation of 250 cGy/fraction/day and 5 mg/kg ATO for 5-10 days. Results: Time course experiments demonstrated that maximal tumor growth delay occurred when ATO was administered between 0 and 4 h after radiation. The combination treatment of ATO and radiation synergistically inhibited tumor growth and produced a tumor growth delay time of 13.2 days, compared with 1.4 days and 6.5 days for ATO and radiation alone (p < 0.01), respectively. The use of concurrent therapy of radiation and ATO initially, followed by ATO as maintenance therapy, was superior to the use of preloading with ATO before combined therapy and produced a tumor growth delay time of 22.7 days as compared with 11.7 days for the ATO preloading regimen (p < 0.01). The maintenance dose of ATO after concurrent therapy was effective and important for continued inhibition of tumor growth. Conclusions: The combined use of fractionated radiation and ATO is effective for the treatment of glioma xenograft tumors. ATO was most effective when administered 0-4 h after radiation without pretreatment with ATO. These results have important implications for the optimization of treatment regimen using ATO and fractionated radiotherapy for the treatment of brain tumors

  6. Efficacy of whole brain radiotherapy combined with fractionated stereotactic radiotherapy in metastatic brain tumors, and prognostic factors

    We attempted to analyze the effectiveness of whole brain radiotherapy (WBRT) combined with fractionated stereotactic radiotherapy (FSRT) in brain metastases. Thirty-seven metastatic brain tumors in 29 patients without previous treatment were treated with WBRT plus FSRT, from October 1996 to February 2002. Four of the patients received stereotactic radiosurgery (SRS) prior to WBRT. Non-small cell lung cancer was the most common type of primary tumor (20/29). The total dose to the whole brain ranged from 30 Gy to 40 Gy, and the boost dose from FSRT ranged from 12 Gy to 40 Gy. End points were survival rate and local control rates. Factors influencing survival were evaluated. Median survival was 13 months, and actuarial survival rates at one and two years were 81% and 39%, respectively. Actuarial one and two year local control rates for all lesions were 78% and 71%, respectively. Survival was significantly associated with age, tumor size, presence of active extracranial tumors, and performance status. No acute or delayed complications were observed. We believe that WBRT plus FSRT should be included in the treatment options for metastatic brain tumors, and we consider the effect of this non-invasive method to be quite good in patients with good prognostic factors, although other invasive modalities could also be effective in them. (author)

  7. Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement

    Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting. (orig.)

  8. Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement

    Droege, L.H.; Hinsche, T.; Hess, C.F.; Wolff, H.A. [University Hospital of Goettingen, Department of Radiotherapy and Radiation Oncology, Goettingen (Germany); Canis, M. [University of Goettingen, Department of Otorhinolaryngology, Head and Neck Surgery, Goettingen (Germany); Alt-Epping, B. [University of Goettingen, Department of Palliative Medicine, Goettingen (Germany)

    2014-02-15

    Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting. (orig.)

  9. Particle-beam accelerators for radiotherapy and radioisotopes

    The philosophy used in developing the new PIGMI technology was that the parameters chosen for physics research machines are not necessarily the right ones for a dedicated therapy or radioisotope machine. In particular, the beam current and energy can be optimized, and the design should emphasize minimum size, simplicity and reliability of operation, and economy in capital and operating costs. A major part of achieving these goals lay in raising the operating frequency and voltage gradient of the accelerator, which shrinks the diameter and length of the components. Several other technical innovations resulted in major system improvements. One of these is a radically new type of accelerator structure named the radio-frequency quadrupole (RFQ) accelerator. This allowed us to eliminate the large, complicated ion source used in previous ion accelerators, and to achieve a very high quality accelerated beam. Also, by using advanced permanent magnet materials to make the focusing elements, the system becomes much simpler. Other improvements have been made in all of the accelerator components and in the methods for operating them. These will be described, and design and costing information examples given for several possible therapy and radioisotope production machines

  10. Study of inter-fractional variations and adaptive radiotherapy in pancreatic cancer

    Objective: To quantitatively characterize the inter-fractional anatomy variations and advantages of dosimetry for the adaptive radiotherapy in pancreatic cancer. Methods: A total of 226 daily CT images acquired from 10 patients with pancreatic cancer treated with image-guided radiotherapy were analyzed retrospectively. Targets and organs at risk (OARs) were delineated by the atlas-based automatic segmentation and modified by the skilled physician. Various parameters,including the center of mass (COM) distance, the maximal overlap ratio (MOR) and the Dice coefficient (DC), were used to quantify the inter-fractional organ displacement and deformation. The adaptive radiation therapy (ART) was applied to handle the daily GT images. The dose distributions parameters from the ART plan were compared with those from the repositioning plan. Results: The inter-fractional anatomy variations of pancreas head were obvious in the pancreatic cancer irradiation. The mean COM distance, MOR and DC of pancreas head after the bony or soft tissue alignment and registration was (7.8 ± 1.3)mm, (87.2 ± 8.4)% and (77.2 ±7.9)% respectively. Compared with the repositioning plan, the ART plan had better target coverage and OARs sparing. For example, the mean V100 of PTV was improved from (93.32 ± 2.89) % for repositioning plan to (96.03 ± 1.42)% for ART plan with t =2.79, P =0.008 and the mean V50.4 for duodenum was reduced from (43.4 ± 12.71)% for the repositioning plan to (15.6 ± 6.25)% for the ART plan with t =3.52, P=0.000. Conclusions: The ART can effectively account for the obvious inter-fractional anatomy variations in pancreatic cancer irradiation and be used to escalate the radiotherapy dose for the pancreatic cancer, which will lead to a promising higher local control rate. (authors)

  11. Optimum radiotherapy schedule for uterine cervical cancer based-on the detailed information of dose fractionation and radiotherapy technique

    Cho, Jae Ho; Kim, Hyun Chang; Suh, Chang Ok [Yonsei University Medical School, Seoul (Korea, Republic of)] (and others)

    2005-09-15

    The best dose-fractionation regimen of the definitive radiotherapy for cervix cancer remains to be clearly determined. It seems to be partially attributed to the complexity of the affecting factors and the lack of detailed information on external and intra-cavitary fractionation. To find optimal practice guidelines, our experiences of the combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) were reviewed with detailed information of the various treatment parameters obtained from a large cohort of women treated homogeneously at a single institute. The subjects were 743 cervical cancer patients (Stage IB 198, IIA 77, IIB 364, IIIA 7, IIIB 89 and IVA 8) treated by radiotherapy alone, between 1990 and 1996. A total external beam radiotherapy (EBRT) dose of 23.4 {approx} 59.4 Gy (Median 45.0) was delivered to the whole pelvis. High-dose-rate intracavitary brachytherapy (HDR-ICBT) was also performed using various fractionation schemes. A Midline block (MLB) was initiated after the delivery of 14.4{approx} 43.2 Gy (Median 36.0) of EBRT in 495 patients, while in the other 248 patients EBRT could not be used due to slow tumor regression or the huge initial bulk of tumor. The point A, actual bladder and rectal doses were individually assessed in all patients. The biologically effective dose (BED) to the tumor ({alpha} / {beta} = 10) and late-responding tissues ({alpha} /{beta} = 3) for both EBRT and HDR-ICBT were calculated. The total BED values to point A, the actual bladder and rectal reference points were the summation of the EBRT and HDR-ICBT. In addition to all the details on dose-fractionation, the other factors (i.e. the overall treatment time, physicians preference) that can affect the schedule of the definitive radiotherapy were also thoroughly analyzed. The association between MD-BED Gy{sub 3} and the risk of complication was assessed using serial multiple logistic regressions models. The associations between R

  12. Quality Assesment Of Photon And Electron Beams From Siemens PRIMUS Radiotherapy Accelerator

    There are two types of radiation from SIEMENS Primus Radiotherapy Accelerator at the National Cancer Hospital (K Hospital): electron and photon beams. Electron beams with four different energies of 6; 9; 12 and 15 MeV. Photon beams with two different energies: 6 MV and 15 MV. The symmetry as well as flatness of profiles created by all these beams are very important factors using in clinical practice. This report presents the method using water phantom to define absorbed dose distribution in medium of all beams. This is an effective and accurate method to define quality of radiation beams with different field sizes using in radiotherapy. (author)

  13. Critical dose and toxicity index of organs at risk in radiotherapy: Analyzing the calculated effects of modified dose fractionation in non–small cell lung cancer

    Pedicini, Piernicola, E-mail: ppiern@libero.it [Service of Medical Physics, I.R.C.C.S. Regional Cancer Hospital C.R.O.B, Rionero in Vulture (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Benassi, Marcello [Service of Medical Physics, Scientific Institute of Tumours of Romagna I.R.S.T., Meldola (Italy); Caivano, Rocchina [Service of Medical Physics, I.R.C.C.S. Regional Cancer Hospital C.R.O.B, Rionero in Vulture (Italy); Fiorentino, Alba [U.O. of Radiotherapy, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy); Nappi, Antonio [U.O. of Nuclear Medicine, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy); Salvatore, Marco [U.O. of Nuclear Medicine, I.R.C.C.S. SDN Foundation, Naples (Italy); Storto, Giovanni [U.O. of Nuclear Medicine, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy)

    2014-04-01

    To increase the efficacy of radiotherapy for non–small cell lung cancer (NSCLC), many schemes of dose fractionation were assessed by a new “toxicity index” (I), which allows one to choose the fractionation schedules that produce less toxic treatments. Thirty-two patients affected by non resectable NSCLC were treated by standard 3-dimensional conformal radiotherapy (3DCRT) with a strategy of limited treated volume. Computed tomography datasets were employed to re plan by simultaneous integrated boost intensity-modulated radiotherapy (IMRT). The dose distributions from plans were used to test various schemes of dose fractionation, in 3DCRT as well as in IMRT, by transforming the dose-volume histogram (DVH) into a biological equivalent DVH (BDVH) and by varying the overall treatment time. The BDVHs were obtained through the toxicity index, which was defined for each of the organs at risk (OAR) by a linear quadratic model keeping an equivalent radiobiological effect on the target volume. The less toxic fractionation consisted in a severe/moderate hyper fractionation for the volume including the primary tumor and lymph nodes, followed by a hypofractionation for the reduced volume of the primary tumor. The 3DCRT and IMRT resulted, respectively, in 4.7% and 4.3% of dose sparing for the spinal cord, without significant changes for the combined-lungs toxicity (p < 0.001). Schedules with reduced overall treatment time (accelerated fractionations) led to a 12.5% dose sparing for the spinal cord (7.5% in IMRT), 8.3% dose sparing for V{sub 20} in the combined lungs (5.5% in IMRT), and also significant dose sparing for all the other OARs (p < 0.001). The toxicity index allows to choose fractionation schedules with reduced toxicity for all the OARs and equivalent radiobiological effect for the tumor in 3DCRT, as well as in IMRT, treatments of NSCLC.

  14. Radiation myelopathy in patients treated for carcinoma of bronchus using a six fraction regime of radiotherapy

    The adoption of a six-fraction regime of radiotherapy for patients with locally advanced carcinoma of the bronchus was followed by the appearance of radiation myelitis in eight cases. These were among a group of 130 patients given radiotherapy with anterior and posterior treatment fields, without shielding of the spinal cord. Radiation myelitis was found only in those where the calculated spinal-cord dose exceeded 3350 cGy(rad). The possible precipitating factors in the eight patients who suffered myelopathy were compared with those in the remaining 62 patients who also received spinal-cord doses calculated to be greater than 3350 cGy(rad). Only one difference was found - the haemoglobin concentration was significantly higher in those who suffered neuropathy compared with those who did not (P=0.05). (U.K.)

  15. Long-term results of fractionated stereotactic radiotherapy as third-line treatment in acromegaly.

    Diallo, Alpha M; Colin, Philippe; Litre, Claude F; Diallo, Mamadou M; Decoudier, Bénédicte; Bertoin, Florence; Higel, Brigitte; Patey, Martine; Rousseaux, Pascal; Delemer, Brigitte

    2015-12-01

    The treatment of acromegaly is based on surgery, drugs, and radiotherapy as a third-line option. Fractionated stereotactic radiotherapy (FSRT) is a new technique with a need for long-term evaluation. The purpose of the study was to evaluate long-term results of FSRT in acromegaly. Overall, 34 patients [sex ratio 1.12, age 45 (5-65) years] with a pituitary adenoma of 24.5 (9-76) mm including 20 invasive tumors were treated by radiotherapy in fractionated stereotactic conditions delivering 50 gy in 27 sessions. Baseline growth hormone (GH) and IGF1 levels were 18 (±14.5) and 632.6 (±339) µg/L, respectively. Indications of FSRT were failure of surgery and drug treatments (n = 30) or contraindication/refusal of surgery (n = 4). Hormonal control was defined by normal age- and sex-adjusted IGF1. Remission was defined by hormonal control after withdrawal of drugs for a minimum of three consecutive months. Data were analyzed in SPSS software with a significance level at p < 0.05. After a mean follow-up of 152 months, hormonal control was achieved in 33 patients (97 %) with withdrawal of drugs in 13 patients (38.2 %) without any recurrence. Factors found to be significantly associated to remission in a multivariate Cox regression were lower baseline hormone levels (GH and IGF1) and smaller tumor size. Tumor control was achieved in all patients. Acquired hypopituitarism after radiotherapy was the main side effect reported with a rate of 39 %. FSRT seems to be an effective and well tolerated third-line treatment of acromegaly, particularly adapted to macro adenomas treatment. PMID:25956280

  16. Hyperfractionated accelerated radiotherapy with concomitant integrated boost of 70-75 Gy in 5 weeks for advanced head and neck cancer. A phase I dose escalation study

    Cvek, J.; Skacelikova, E.; Otahal, B.; Halamka, M.; Feltl, D. [University Hospital Ostrava (Czech Republic). Dept. of Oncology; Kubes, J. [University Hospital Bulovka, Prague (Czech Republic). Dept. of Radiation Oncology; Kominek, P. [University Hospital Ostrava (Czech Republic). Dept. of Otolaryngology

    2012-08-15

    Background and purpose: The present study was performed to evaluate the feasibility of a new, 5-week regimen of 70-75 Gy hyperfractionated accelerated radiotherapy with concomitant integrated boost (HARTCIB) for locally advanced, inoperable head and neck cancer. Methods and materials: A total of 39 patients with very advanced, stage IV nonmetastatic head and neck squamous cell carcinoma (median gross tumor volume 72 ml) were included in this phase I dose escalation study. A total of 50 fractions intensity-modulated radiotherapy (IMRT) were administered twice daily over 5 weeks. Prescribed total dose/dose per fraction for planning target volume (PTV{sub tumor}) were 70 Gy in 1.4 Gy fractions, 72.5 Gy in 1.45 Gy fractions, and 75 Gy in 1.5 Gy fractions for 10, 13, and 16 patients, respectively. Uninvolved lymphatic nodes (PTV{sub uninvolved}) were irradiated with 55 Gy in 1.1 Gy fractions using the concomitant integrated boost. Results: Acute toxicity was evaluated according to the RTOG/EORTC scale; the incidence of grade 3 mucositis was 51% in the oral cavity/pharynx and 0% in skin and the recovery time was {<=} 9 weeks for all patients. Late toxicity was evaluated in patients in complete remission according to the RTOG/EORTC scale. No grade 3/4 late toxicity was observed. The 1-year locoregional progression-free survival was 50% and overall survival was 55%. Conclusion: HARTCIB (75 Gy in 5 weeks) is feasible for patients deemed unsuitable for chemoradiation. Acute toxicity was lower than predicted from radiobiological models; duration of dysphagia and confluent mucositis were particularly short. Better conformity of radiotherapy allows the use of more intensive altered fractionation schedules compared with older studies. These results suggest that further dose escalation might be possible when highly conformal techniques (e.g., stereotactic radiotherapy) are used.

  17. Bevacizumab, Capecitabine, Amifostine, and Preoperative Hypofractionated Accelerated Radiotherapy (HypoArc) for Rectal Cancer: A Phase II Study

    Purpose: Bevacizumab has established therapeutic activity in patients with metastatic colorectal cancer, and anti-vascular endothelial growth factor therapy enhances the activity of radiotherapy in experimental models. We assessed the feasibility and efficacy of preoperative radiochemotherapy combined with bevacizumab in patients with rectal cancer. Methods and Materials: Nineteen patients with radiologic T3 and/or N+ rectal carcinoma were treated with preoperative conformal hypofractionated accelerated radiotherapy (3.4 Gy in 10 consecutive fractions) supported with amifostine (500-1,000 mg daily), capecitabine (600 mg/m2 twice daily, 5 days per week), and bevacizumab (5 mg/kg every 2 weeks for 2 cycles). Surgery followed 6 weeks after the end of radiotherapy. A cohort of 14 sequential patients treated with the same regimen without bevacizumab was available for comparison. Results: Grade 2 or 3 diarrhea was noted in 7 of 19 patients (36.8%), which was statistically worse than patients receiving the same regimen without bevacizumab (p = 0.01). A higher incidence of Grade 2 or 3 proctalgia was also noted (21.1%) (p = 0.03). Bladder and skin toxicity was negligible. All toxicities regressed completely within 2 weeks after the end of therapy. Pathologic complete and partial response was noted in 7 of 19 cases (36.8%) and 8 of 19 cases (42.1%). Within a median follow-up of 21 months, none of the patients has had late complications develop and only 1 of 18 evaluable cases (5.5%) has had locoregional relapse. Conclusions: Bevacizumab can be safely combined with hypofractionated radiotherapy and capecitabine as a preoperative radiochemotherapy regimen for patients with rectal cancer. The high pathologic complete response rates urges the testing of bevacizumab in randomized studies.

  18. Accelerated ray tracing for radiotherapy dose calculations on a GPU

    M. de Greef; J. Crezee; J.C. van Eijk; R. Pool; A. Bel

    2009-01-01

    PURPOSE: The graphical processing unit (GPU) on modern graphics cards offers the possibility of accelerating arithmetically intensive tasks. By splitting the work into a large number of independent jobs, order-of-magnitude speedups are reported. In this article, the possible speedup of PLATO's ray t

  19. Low or High Fractionation Dose β-Radiotherapy for Pterygium? A Randomized Clinical Trial

    Purpose: Postoperative adjuvant treatment using β-radiotherapy (RT) is a proven technique for reducing the recurrence of pterygium. A randomized trial was conducted to determine whether a low fractionation dose of 2 Gy within 10 fractions would provide local control similar to that after a high fractionation dose of 5 Gy within 7 fractions for surgically resected pterygium. Methods: A randomized trial was conducted in 200 patients (216 pterygia) between February 2006 and July 2007. Only patients with fresh pterygium resected using a bare sclera method and given RT within 3 days were included. Postoperative RT was delivered using a strontium-90 eye applicator. The pterygia were randomly treated using either 5 Gy within 7 fractions (Group 1) or 2 Gy within 10 fractions (Group 2). The local control rate was calculated from the date of surgery. Results: Of the 216 pterygia included, 112 were allocated to Group 1 and 104 to Group 2. The 3-year local control rate for Groups 1 and 2 was 93.8% and 92.3%, respectively (p = .616). A statistically significant difference for cosmetic effect (p = .034), photophobia (p = .02), irritation (p = .001), and scleromalacia (p = .017) was noted in favor of Group 2. Conclusions: No better local control rate for postoperative pterygium was obtained using high-dose fractionation vs. low-dose fractionation. However, a low-dose fractionation schedule produced better cosmetic effects and resulted in fewer symptoms than high-dose fractionation. Moreover, pterygia can be safely treated in terms of local recurrence using RT schedules with a biologic effective dose of 24–52.5 Gy10.

  20. Low or High Fractionation Dose {beta}-Radiotherapy for Pterygium? A Randomized Clinical Trial

    Viani, Gustavo Arruda, E-mail: gusviani@gmail.com [Department of Radiation Oncology, Marilia Medicine School, Sao Paulo, SP (Brazil); De Fendi, Ligia Issa; Fonseca, Ellen Carrara [Department of Ophthalmology, Marilia Medicine School, Sao Paulo, SP (Brazil); Stefano, Eduardo Jose [Department of Radiation Oncology, Marilia Medicine School, Sao Paulo, SP (Brazil)

    2012-02-01

    Purpose: Postoperative adjuvant treatment using {beta}-radiotherapy (RT) is a proven technique for reducing the recurrence of pterygium. A randomized trial was conducted to determine whether a low fractionation dose of 2 Gy within 10 fractions would provide local control similar to that after a high fractionation dose of 5 Gy within 7 fractions for surgically resected pterygium. Methods: A randomized trial was conducted in 200 patients (216 pterygia) between February 2006 and July 2007. Only patients with fresh pterygium resected using a bare sclera method and given RT within 3 days were included. Postoperative RT was delivered using a strontium-90 eye applicator. The pterygia were randomly treated using either 5 Gy within 7 fractions (Group 1) or 2 Gy within 10 fractions (Group 2). The local control rate was calculated from the date of surgery. Results: Of the 216 pterygia included, 112 were allocated to Group 1 and 104 to Group 2. The 3-year local control rate for Groups 1 and 2 was 93.8% and 92.3%, respectively (p = .616). A statistically significant difference for cosmetic effect (p = .034), photophobia (p = .02), irritation (p = .001), and scleromalacia (p = .017) was noted in favor of Group 2. Conclusions: No better local control rate for postoperative pterygium was obtained using high-dose fractionation vs. low-dose fractionation. However, a low-dose fractionation schedule produced better cosmetic effects and resulted in fewer symptoms than high-dose fractionation. Moreover, pterygia can be safely treated in terms of local recurrence using RT schedules with a biologic effective dose of 24-52.5 Gy{sub 10.}.

  1. A Population-based Study of the Fractionation of Palliative Radiotherapy for Bone Metastasis in Ontario

    Purpose: To describe the use of palliative radiotherapy (PRT) for bone metastases in Ontario between 1984 and 2001 and identify factors associated with the choice of fractionation. Methods and Materials: Electronic RT records from the nine provincial RT centers in Ontario were linked to the Ontario Cancer Registry to identify all courses of PRT for bone metastases. Results: Between 1984 and 2001, 44,884 patients received 74,432 courses of PRT for bone metastases in Ontario. The mean number of courses per patient was 1.7, and 65% of patients received only a single course of PRT for bone metastasis. The mean number of fractions per course was 3.9. The proportion of patients treated with a single fraction increased from 27.2% in 1984-1986 to 40.3% in 1987-1992 and decreased thereafter. Single fractions were used more frequently in patients with a shorter life expectancy, in older patients, and in patients who lived further from an RT center. Single fractions were used more frequently when the prevailing waiting time for RT was longer. There were wide variations in the use of single fractions among the different RT centers (intercenter range, 11.8-62.3%). Intercenter variations persisted throughout the study period and were not explained by differences in case mix. Conclusions: Despite increasing evidence of the effectiveness of single-fraction PRT for bone metastases, most patients continued to receive fractionated PRT throughout the two decades of this study. Single fractions were used more frequently when waiting times were longer. There was persistent, unexplained variation in the fractionation of PRT among different centers

  2. Radiotherapy of the rhabdomyosarcoma R1H of the rat: Split-course versus continuous fractionation

    Fractionated split-course treatments were given with gaps of different length and the effect on tumor response was studied using the rhabdomyosarcoma R1H of the rat. Total doses of 68, 75 and 82 Gy were applied in 30 fractions (five fractions per week). After four weeks, that is after 20 fractions, treatment was interrupted for one or two weeks followed by another ten fractions. The results were compared to those of continuous treatment given in six consecutive weeks. Tumor response was quantified by TCD37% and net growth delay. The TCD37% increased with increasing duration of the gap. A mean repopulated dose of 0.72 Gy per day was obtained. This corresponds to a doubling time of tumor clonogens of 4.2 days during the gap, which is somewhat slower than the volume doubling time of unperturbed tumors (2.5 days) of the same size. The results obtained for the net growth delay support the results of the TCD37% data. It is concluded that a gap during fractionated radiotherapy leads to poorer results since the dose required for tumor control is enhanced and sparing of normal tissue can only be expected for early but not for late reacting tissues. (orig.)

  3. Study of the Accelerator Technology Development for Cancer Radiotherapy

    The hadronic particle beams including both protons, neutrons and charged particles have been studied for cancer therapy by a number of research centers in several countries during the past two decades. In this paper is briefly discussed concerning the accelerator type and its applications. The future trends are seen in the new technological developments like the use of proton gantries, beam scanning techniques, improved patient handling system and in the increasing precision of treatment. (author)

  4. Stereotactic radiotherapy (SRT) for acoustic neuroma by linear accelerator

    Sakamoto, Tooru; Shirato, Hiroki; Fukuda, Satoshi [Hokkaido Univ., Sapporo (Japan). School of Medicine] [and others

    1997-10-01

    We analyzed forty one patients with acoustic neuroma treated by SRT giving 36 Gy in 20 fractions to 48 Gy in 23 fractions during 1991 and 1997, and found a sterilization of tumor size in 97.6%. Twenty-six patients had measurable hearing before and after SRT and 43.5% of patients showed change in pure tone average less than 10 dB, 82.6% less than 20 dB at the last follow-up examination. Facial and trigeminal nerve function was evaluated in 41 patients. Transient facial weakness developed in 4.8% and trigeminal neuropathy in 9.6% of irradiated cases. We consider that SRT complications are less than that of gamma-knife, although the longer follow-up period should be needed. (author)

  5. In Vivo Dosimetry for Single-Fraction Targeted Intraoperative Radiotherapy (TARGIT) for Breast Cancer

    Purpose: In vivo dosimetry provides an independent check of delivered dose and gives confidence in the introduction or consistency of radiotherapy techniques. Single-fraction intraoperative radiotherapy of the breast can be performed with the Intrabeam compact, mobile 50 kV x-ray source (Carl Zeiss Surgical, Oberkochen, Germany). Thermoluminescent dosimeters (TLDs) can be used to estimate skin doses during these treatments. Methods and Materials: Measurements of skin doses were taken using TLDs for 72 patients over 3 years of clinical treatments. Phantom studies were also undertaken to assess the uncertainties resulting from changes in beam quality and backscatter conditions in vivo. Results: The mean measured skin dose was 2.9 ± 1.6 Gy, with 11% of readings higher than the prescription dose of 6 Gy, but none of these patients showed increased complications. Uncertainties due to beam hardening and backscatter reduction were small compared with overall accuracy. Conclusions: TLDs are a useful and effective method to measure in vivo skin doses in intraoperative radiotherapy and are recommended for the initial validation or any modification to the delivery of this technique. They are also an effective tool to show consistent and safe delivery on a more frequent basis or to determine doses to other critical structures as required.

  6. The results of accelerated radiotherapy and concomitant cisplatin administration in advanced oropharyngeal cancer

    The accelerated radiotherapy and concomitant infusion of cisplatin in low doses was evaluated in 15 patients with advanced squamous cell carcinoma of the oral cavity and oral part of pharynx. Clinical complete response was seen in 6 of 15 patients (40%) and 4 patients (26.6%) were alive 12 months with no evidence of disease, of all group of 15 patients 9 (60%) were alive 12 months after treatment. (author)

  7. Acceleration of pubertal development following pituitary radiotherapy for Cushing's disease

    Nicholl, R.M.; Kirk, J.M.W.; Grossman, A.B.; Plowman, P.N.; Besser, G.M.; Savage, M.O. (Saint Bartholomew' s Hospital, London (United Kingdom))

    1993-01-01

    A 7-year-old boy with pituitary dependent Cushing's disease was treated with pituitary irradiation following unsuccessful microadenomectomy. This led to normalization of the hypercortisolaemia, but was followed by GH deficiency. Two years after radiotherapy he had the onset of pubertal development with testicular enlargement to 8 ml bilaterally. Pubertal regression was induced using the long-acting GnRH analogue goserelin. Acceleration of skeletal maturation was also arrested, resulting in improvement of final height prediction. Irradiation directly to the hypothalamo-pituitary region, as well as whole brain irradiation, may thus be associated with accelerated pubertal development. (author).

  8. Physical-dosimetric enabling a dual linear accelerator 3D planning systems for radiotherapy

    The process of commissioning clinical linear accelerator requires a dual comprehensive study of the therapeutic beam parameters, both photons Electron. All information gained by measuring physical and dosimetric these beams must be analyzed, processed and refined for further modeling in computer-based treatment planning (RTPS). Of professionalism of this process will depend on the accuracy and precision of the calculations the prescribed doses. This paper aims to demonstrate availability clinical linear accelerator system-RTPS with late radiotherapy treatments shaped beam of photons and electrons. (author)

  9. The role of replanning in fractionated intensity modulated radiotherapy for nasopharyngeal carcinoma

    Background and purpose: Anatomic changing frequently occurred during fractionated radiotherapy. The aims of this study were to model the potential benefit of adaptive IMRT replanning during fractionated radiotherapy and its potential advantage over clinical outcome in patients with nasopharyngeal carcinoma. Materials and methods: Thirty-three patients with repeat CT imaging and replanning were retrospectively analyzed. 66 case-matched control patients without replanning were identified by matching for AJCC stage, gender, and age. Hybrid IMRT plans were generated to evaluate the dosimetric changing. Mann-Whitney-Wilcoxon tests were used to evaluate the effect of replanning on volumetric and dosimetric outcomes within individuals. Kaplan-Meier estimators were used to estimate the survival function of patients with or without replanning. Results: The mean volume of the ipsilateral and contralateral parotid glands decreased during the treatment. The hybrid IMRT plans showed decreased doses to target volumes and increased doses to normal structures in replanning. The clinical outcome comparison indicated that the IMRT replanning improved the 3 years local progression-free survival for patients who had AJCC staged more than T3 (T3,4Nx) and ease the late effects for patients who had large lymph nodes (AJCC stage TxN2,3). Conclusion: Repeat CT imaging and IMRT replanning were recommendatory for specific nasopharyngeal carcinoma patients.

  10. A comparison of anatomical and dosimetric variations in the first 15 fractions, and between fractions 16 and 25, of intensity-modulated radiotherapy for nasopharyngeal carcinoma.

    Yang, Haihua; Tu, Yu; Wang, Wei; Hu, Wei; Ding, Weijun; Yu, Changhui; Zhou, Chao

    2013-01-01

    The purpose of this study was to compare anatomical and dosimetric variations in first 15 fractions, and between fractions 16 and 25, during intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC). Twenty-three NPC patients who received IMRT in 33 fractions were enrolled. Each patient had two repeat computed tomography (CT) scans before the 16th and 25th fraction. Hybrid IMRT plans were generated to evaluate the dosimetric changes. There was a significant decrease of the transverse diameter of nasopharyngeal and neck as well as gross tumor volume (GTV) in the primary nasopharyngeal carcinoma (GTVnx) and involved lymph nodes (GTVnd) during the first 15 fractions, and between fraction 16 and 25 (p anatomic changes resulted in more predominant dosimetric effects in the first 15 fractions, and between fractions 16 and 25, of IMRT. PMID:24257268

  11. Prospective randomised multicenter trial on single fraction radiotherapy (8 Gyx1) versus multiple fractions (3 Gyx10) in the treatment of painful bone metastases

    Background and purpose: To investigate whether single-fraction radiotherapy is equal to multiple fractions in the treatment of painful metastases. Patients and methods: The study planned to recruit 1000 patients with painful bone metastases from four Norwegian and six Swedish hospitals. Patients were randomized to single-fraction (8 Gyx1) or multiple-fraction (3 Gyx10) radiotherapy. The primary endpoint of the study was pain relief, with fatigue and global quality of life as the secondary endpoints. Results: The data monitoring committee recommended closure of the study after 376 patients had been recruited because interim analyses indicated that, as in two other recently published trials, the treatment groups had similar outcomes. Both groups experienced similar pain relief within the first 4 months, and this was maintained throughout the 28-week follow-up. No differences were found for fatigue and global quality of life. Survival was similar in both groups, with median survival of 8-9 months. Conclusions: Single-fraction 8 Gy and multiple-fraction radiotherapy provide similar pain benefit. These results, confirming those of other studies, indicate that single-fraction 8 Gy should be standard management policy for these patients

  12. Radiotherapy

    This review highlights developments over the past decade in radiotherapy and attempts to summarize the state of the art in the management of the major diseases in which radiotherapy has a meaningful role. The equipment, radiobiology of radiotherapy and carcinoma of the lung, breast and intestines are highlighted

  13. TLD Intercomparison in accelerators for radiotherapy in three Latin american countries

    In Radiotherapy one of the objectives is to establish and to give follow up to quality assurance programs which make sure that the doses administered to the patients with cancer are a high probability of a success in external radiation. Likewise, one of the present preoccupations of the United Nations Agencies as well as the International Atomic Energy Agency and the Pan-American Health Organization is the optimal employment of the radiations in the treatment of cancer patients since the administered dose in Radiotherapy suffers considerable variations by the lack of quality assurance programs. The use of Electron linear accelerators requires a program of quality assurance that includes expert personnel, equipment and adequate facilities. The more used methodology for the dosimetry calibration and characterization of X-ray beams and high energy electrons for radiotherapy use is using a ionization chamber dosemeter calibrated in a regional secondary standardization laboratory. However, to establish and give follow up to the quality assurance programs it is necessary the dosimetric intercomparison through TLD. In this study it was designed plastic phantoms with TLD crystals and it was made its characterization to realize an absorbed dose analysis in the crystals exposed at X-ray beams 6 MV and high energy electrons 10 and 12 MeV to standardize the dosimetric procedures and proceeding to realize an International Pilot intercomparison of absorbed doses in TLD crystals in three Latin American countries: Mexico, Peru and Colombia with the participation of accelerators of five different institutions. The found results show that the majority of the measured doses with TLD in the different accelerators were in the 0.95-1.05 range though it had two cases outside of this range. The use of the phantoms with TLD crystals shows that they are of excellent aid to make analysis of the doses administered to the patients and an intercomparison of results to standardize procedures at

  14. Accelerated hypofractionated radiation therapy compared to conventionally fractionated radiation therapy for the treatment of inoperable non-small cell lung cancer

    Amini Arya

    2012-03-01

    Full Text Available Abstract Background While conventionally fractionated radiation therapy alone is an acceptable option for poor prognostic patients with unresectable stage III NSCLC, we hypothesized that accelerated hypofractionated radiotherapy will have similar efficacy without increasing toxicity. Methods This is a retrospective analysis of 300 patients diagnosed with stage III NSCLC treated between 1993 and 2009. Patients included in the study were medically or surgically inoperable, were free of metastatic disease at initial workup and did not receive concurrent chemotherapy. Patients were categorized into three groups. Group 1 received 45 Gy in 15 fractions over 3 weeks (Accelerated Radiotherapy (ACRT while group 2 received 60-63 Gy (Standard Radiation Therapy 1 (STRT1 and group 3 received > 63 Gy (Standard Radiation Therapy (STRT2. Results There were 119 (39.7% patients in the ACRT group, 90 (30.0% in STRT1 and 91 (30.3% in STRT2. More patients in the ACRT group had KPS ≤ 60 (p 5% (p = 0.002, and had stage 3B disease (p Conclusions Despite the limitations of a retrospective analysis, our experience of accelerated hypofractionated radiation therapy with 45 Gy in 15 fractions appears to be an acceptable treatment option for poor performance status patients with stage III inoperable tumors. Such a treatment regimen (or higher doses in 15 fractions should be prospectively evaluated using modern radiation technologies with the addition of sequential high dose chemotherapy in stage III NSCLC.

  15. A meta-analysis of hyperfractionated and accelerated radiotherapy and combined chemotherapy and radiotherapy regimens in unresected locally advanced squamous cell carcinoma of the head and neck

    Former meta-analyses have shown a survival benefit for the addition of chemotherapy (CHX) to radiotherapy (RT) and to some extent also for the use of hyperfractionated radiation therapy (HFRT) and accelerated radiation therapy (AFRT) in locally advanced squamous cell carcinoma (SCC) of the head and neck. However, the publication of new studies and the fact that many older studies that were included in these former meta-analyses used obsolete radiation doses, CHX schedules or study designs prompted us to carry out a new analysis using strict inclusion criteria. Randomised trials testing curatively intended RT (≥60 Gy in >4 weeks/>50 Gy in <4 weeks) on SCC of the oral cavity, oropharynx, hypopharynx, and larynx published as full paper or in abstract form between 1975 and 2003 were eligible. Trials comparing RT alone with concurrent or alternating chemoradiation (5-fluorouracil (5-FU), cisplatin, carboplatin, mitomycin C) were analyzed according to the employed radiation schedule and the used CHX regimen. Studies comparing conventionally fractionated radiotherapy (CFRT) with either HFRT or AFRT without CHX were separately examined. End point of the meta-analysis was overall survival. Thirty-two trials with a total of 10 225 patients were included into the meta-analysis. An overall survival benefit of 12.0 months was observed for the addition of simultaneous CHX to either CFRT or HFRT/AFRT (p < 0.001). Separate analyses by cytostatic drug indicate a prolongation of survival of 24.0 months, 16.8 months, 6.7 months, and 4.0 months, respectively, for the simultaneous administration of 5-FU, cisplatin-based, carboplatin-based, and mitomycin C-based CHX to RT (each p < 0.01). Whereas no significant gain in overall survival was observed for AFRT in comparison to CFRT, a substantial prolongation of median survival (14.2 months, p < 0.001) was seen for HFRT compared to CFRT (both without CHX). RT combined with simultaneous 5-FU, cisplatin, carboplatin, and mitomycin C as

  16. Single Fraction Versus Fractionated Linac-Based Stereotactic Radiotherapy for Vestibular Schwannoma: A Single-Institution Experience

    Collen, Christine, E-mail: ccollen@uzbrussel.be [Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Ampe, Ben [Department of Neurosurgery, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Gevaert, Thierry [Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Moens, Maarten [Department of Neurosurgery, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Linthout, Nadine; De Ridder, Mark; Verellen, Dirk [Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); D' Haens, Jean [Department of Neurosurgery, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Storme, Guy [Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium)

    2011-11-15

    Purpose: To evaluate and compare outcomes for patients with vestibular schwannoma (VS) treated in a single institution with linac-based stereotactic radiosurgery (SRS) or by fractionated stereotactic radiotherapy (SRT). Methods and Materials: One hundred and nineteen patients (SRS = 78, SRT = 41) were treated. For both SRS and SRT, beam shaping is performed by a mini-multileaf collimator. For SRS, a median single dose of 12.5 Gy (range, 11-14 Gy), prescribed to the 80% isodose line encompassing the target, was applied. Of the 42 SRT treatments, 32 treatments consisted of 10 fractions of 3-4 Gy, and 10 patients received 25 sessions of 2 Gy, prescribed to the 100% with the 95% isodose line encompassing the planning target volume. Mean largest tumor diameter was 16.6 mm in the SRS and 24.6 mm in the SRT group. Local tumor control, cranial nerve toxicity, and preservation of useful hearing were recorded. Any new treatment-induced cranial nerve neuropathy was scored as a complication. Results: Median follow-up was 62 months (range, 6-136 months), 5 patients progressed, resulting in an overall 5-year local tumor control of 95%. The overall 5-year facial nerve preservation probability was 88% and facial nerve neuropathy was statistically significantly higher after SRS, after prior surgery, for larger tumors, and in Koos Grade {>=}3. The overall 5-year trigeminal nerve preservation probability was 96%, not significantly influenced by any of the risk factors. The overall 4-year probability of preservation of useful hearing (Gardner-Robertson score 1 or 2) was 68%, not significantly different between SRS or SRT (59% vs. 82%, p = 0.089, log rank). Conclusion: Linac-based RT results in good local control and acceptable clinical outcome in small to medium-sized vestibular schwannomas (VSs). Radiosurgery for large VSs (Koos Grade {>=}3) remains a challenge because of increased facial nerve neuropathy.

  17. Single Fraction Versus Fractionated Linac-Based Stereotactic Radiotherapy for Vestibular Schwannoma: A Single-Institution Experience

    Purpose: To evaluate and compare outcomes for patients with vestibular schwannoma (VS) treated in a single institution with linac-based stereotactic radiosurgery (SRS) or by fractionated stereotactic radiotherapy (SRT). Methods and Materials: One hundred and nineteen patients (SRS = 78, SRT = 41) were treated. For both SRS and SRT, beam shaping is performed by a mini-multileaf collimator. For SRS, a median single dose of 12.5 Gy (range, 11–14 Gy), prescribed to the 80% isodose line encompassing the target, was applied. Of the 42 SRT treatments, 32 treatments consisted of 10 fractions of 3–4 Gy, and 10 patients received 25 sessions of 2 Gy, prescribed to the 100% with the 95% isodose line encompassing the planning target volume. Mean largest tumor diameter was 16.6 mm in the SRS and 24.6 mm in the SRT group. Local tumor control, cranial nerve toxicity, and preservation of useful hearing were recorded. Any new treatment-induced cranial nerve neuropathy was scored as a complication. Results: Median follow-up was 62 months (range, 6–136 months), 5 patients progressed, resulting in an overall 5-year local tumor control of 95%. The overall 5-year facial nerve preservation probability was 88% and facial nerve neuropathy was statistically significantly higher after SRS, after prior surgery, for larger tumors, and in Koos Grade ≥3. The overall 5-year trigeminal nerve preservation probability was 96%, not significantly influenced by any of the risk factors. The overall 4-year probability of preservation of useful hearing (Gardner-Robertson score 1 or 2) was 68%, not significantly different between SRS or SRT (59% vs. 82%, p = 0.089, log rank). Conclusion: Linac-based RT results in good local control and acceptable clinical outcome in small to medium-sized vestibular schwannomas (VSs). Radiosurgery for large VSs (Koos Grade ≥3) remains a challenge because of increased facial nerve neuropathy.

  18. Predictors for Clinical Outcomes After Accelerated Partial Breast Intensity-Modulated Radiotherapy

    Purpose: To correlate the treatment planning parameters with the clinical outcomes in patients treated with accelerated partial breast intensity-modulated radiotherapy. Methods and Materials: A total of 105 patients with Stage I breast cancer were treated between February 2004 and March 2007 in a Phase II prospective trial and had detailed information available on the planning target volume (PTV), ipsilateral breast volume (IBV), PTV/IBV ratio, lung volume, chest wall volume, surgery to radiotherapy interval, follow-up interval, breast pain, and cosmesis. The first 7 of these patients were treated to 34 Gy, and the remaining 98 were treated to 38.5 Gy. All patients were treated twice daily for 5 consecutive days. Univariate and multivariate analyses were performed. Results: The median follow-up was 13 months. No recurrences or deaths were observed. Of the 105 patients, 30 reported mild or moderate breast pain in their most recently recorded follow-up visit. The irradiated lung volume (p 35 Gy (p 35 Gy) and to lung correlated with reports of mild pain after accelerated partial breast intensity-modulated radiotherapy. Also, the PTV, but not the PTV/IBV ratio, was predictive of post-treatment reports of pain.

  19. Fractionated stereotactic radiotherapy boost for gynecologic tumors: An alternative to brachytherapy?

    Purpose: A brachytherapy (BT) boost to the vaginal vault is considered standard treatment for many endometrial or cervical cancers. We aimed to challenge this treatment standard by using stereotactic radiotherapy (SRT) with a linac-based micromultileaf collimator technique. Methods and Materials: Since January 2002, 16 patients with either endometrial (9) or cervical (7) cancer have been treated with a final boost to the areas at higher risk for relapse. In 14 patients, the target volume included the vaginal vault, the upper vagina, the parametria, or (if not operated) the uterus (clinical target volume [CTV]). In 2 patients with local relapse, the CTV was the tumor in the vaginal stump. Margins of 6-10 mm were added to the CTV to define the planning target volume (PTV). Hypofractionated dynamic-arc or intensity-modulated radiotherapy techniques were used. Postoperative treatment was delivered in 12 patients (2 x 7 Gy to the PTV with a 4-7-day interval between fractions). In the 4 nonoperated patients, a dose of 4 Gy/fraction in 5 fractions with 2 to 3 days' interval was delivered. Patients were immobilized in a customized vacuum body cast and optimally repositioned with an infrared-guided system developed for extracranial SRT. To further optimize daily repositioning and target immobilization, an inflated rectal balloon was used during each treatment fraction. In 10 patients, CT resimulation was performed before the last boost fraction to assess for repositioning reproducibility via CT-to-CT registration and to estimate PTV safety margins around the CTV. Finally, a comparative treatment planning study between BT and SRT was performed in 2 patients with an operated endometrial Stage I cancer. Results: No patient developed severe acute urinary or low-intestinal toxicity. No patient developed urinary late effects (>6 months). One patient with a vaginal relapse previously irradiated to the pelvic region presented with Grade 3 rectal bleeding 18 months after retreatment

  20. Toshiba's accelerator technology and approach toward higher performance and downsizing for heavy-ion radiotherapy

    Toshiba has developed various systems and components for particle beam accelerators, and delivered a number of accelerator systems including for SPring-8, which is the world's largest-class synchrotron radiation facility, as well as for the Central Japan Synchrotron Radiation Facility (provisional name). Combining our proprietary technologies cultivated through our experience in the development of particle beam accelerators, we are promoting the development of an accelerator for heavy-ion radiotherapy. Toward the higher performance and downsizing of its accelerator, we are also focusing on the research and development of both an ion source applying laser beam technologies, and a superconducting deflecting magnet for accelerators. (author)

  1. Biological dose representation for carbon-ion radiotherapy of unconventional fractionation

    Kanematsu, Nobuyuki

    2016-01-01

    In carbon-ion radiotherapy, single-beam delivery each day in alternate directions has been commonly practiced for operational efficiency, taking advantage of the Bragg peak and the relative biological effectiveness (RBE) for uniform dose conformation to a tumor. The treatment plans are usually evaluated with total RBE-weighted dose, which is however deficient in relevance to the biological effect in the linear-quadratic model due to its quadratic-dose term, or the dose-fractionation effect. In this study, we reformulate the extrapolated response dose (ERD), or synonymously BED, which normalizes the dose-fractionation and cell-repopulation effects as well as the RBE of treating radiation, based on inactivation of a single model cell system and a typical treating radiation in carbon-ion RT. The ERD distribution virtually represents the biological effect of the treatment regardless of radiation modality or fractionation scheme. We applied the ERD formulation to simplistic model treatments and to a preclinical su...

  2. Dose-Escalation Study of Single-Fraction Stereotactic Body Radiotherapy for Liver Malignancies

    Purpose: We performed a Phase I dose-escalation study to explore the feasibility and safety of treating primary and metastatic liver tumors with single-fraction stereotactic body radiotherapy (SBRT). Methods and Materials: Between February 2004 and February 2008, 26 patients were treated for 40 identifiable lesions. Nineteen patients had hepatic metastases, 5 had intrahepatic cholangiocarcinomas, and 2 had recurrent hepatocellular carcinomas. The prescribed radiation dose was escalated from 18 to 30 Gy at 4-Gy increments with a planned maximum dose of 30 Gy. Cumulative incidence functions accounted for competing risks to estimate local failure (LF) incidence over time under the competing risk of death. Results: All patients tolerated the single-fraction SBRT well without developing a dose-limiting toxicity. Nine acute Grade 1 toxicities, one acute Grade 2 toxicity, and two late Grade 2 gastrointestinal toxicities were observed. After a median of 17 months follow-up (range, 2-55 months), the cumulative risk of LF at 12 months was 23%. Fifteen patients have died: 11 treated for liver metastases and 4 with primary liver tumors died. The median survival was 28.6 months, and the 2-year actuarial overall survival was 50.4%. Conclusions: It is feasible and safe to deliver single-fraction, high-dose SBRT to primary or metastatic liver malignancies measuring ≤5 cm. Moreover, single-fraction SBRT for liver lesions demonstrated promising local tumor control with minimal acute and long-term toxicity. Single-fraction SBRT appears to be a viable nonsurgical option, but further studies are warranted to evaluate both control rates and impact on quality of life.

  3. Fractionation and delivery schedules in combined radiotherapy-cisplatin for head and neck cancer

    Full text: Since Rosenberg's initial discovery, cisplatin has become one of the most effective anticancer drugs, with particular significance in head and neck cancer. For advanced disease, where the tumour is unresectable, radiotherapy and chemotherapy, either singularly or combined, remain the possible therapeutic modalities. The majority of the trials using a combination of cisplatin and radiation obtained much better results than the single-agent trials. But the best schedule, dosage and timing between radiation and drug administration are still unknown. Many positive steps were however made to eliminate the cisplatin-produced side effects, as much as possible. The tendency in current trials is to fractionate the drug dose by daily administration and also to hyperfractionate the radiation. In this way the long-term benefits are improved and the toxicity is better tolerated

  4. Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP

    At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

  5. Micronuclei in cytokinesis-blocked lymphocytes of cancer patients following fractionated partial-body radiotherapy

    The cytokinesis-block micronucleus assay was used to measure chromosome damage in lymphocytes of 11 cancer patients undergoing fractionated partial-body irradiation. Measurements performed before, during and after cessation of radiotherapy showed a dose-related increase in micronucleus frequency in each patient studied. When results for micronucleus frequency (Y) were plotted against estimated equivalent whole-body dose (X) the dose-response relationship obtained was Y = 75.8X + 49.5 (r = 0.783, P<0.0001). A general decline in MN frequency was observed during the post-treatment period down to 57% (±10) after 12 months but with considerable variation between individuals. Advantages and disadvantages of the application of the cytokinesis-block micronucleus assay as a biological dosemeter for lymphocytes irradiated in vivo are discussed. (author)

  6. Fractionated External Beam Radiotherapy as a Suitable Preparative Regimen for Hepatocyte Transplantation After Partial Hepatectomy

    Purpose: Hepatocyte transplantation is strongly considered to be a promising option to correct chronic liver failure through repopulation of the diseased organ. We already reported on extensive liver repopulation by hepatocytes transplanted into rats preconditioned with 25-Gy single dose selective external beam irradiation (IR). Herein, we tested lower radiation doses and fractionated protocols, which would be applicable in clinical use. Methods and Material: Livers of dipeptidylpeptidase IV (DPPIV)-deficient rats were preconditioned with partial liver external beam single dose IR at 25 Gy, 8 Gy, or 5 Gy, or fractionated IR at 5 x 5 Gy or 5 x 2 Gy. Four days after completion of IR, a partial hepatectomy (PH) was performed to resect the untreated liver section. Subsequently, 12 million wild-type (DPPIV+) hepatocytes were transplanted via the spleen into the recipient livers. The degree of donor cell integration and liver repopulation was studied 16 weeks after transplantation by means of immunofluorescence and DPPIV-luminescence assay. Results: Donor hepatocyte integration and liver repopulation were more effective in the irradiated livers following pretreatment with the IR doses 1 x 25 Gy and 5 x 5 Gy (formation of large DPPIV-positive cell clusters) than single-dose irradiation at 8 Gy or 5 Gy (DPPIV-positive clusters noticeably smaller and less frequent). Quantitative analysis of extracted DPPIV revealed signals exceeding the control level in all transplanted animals treated with IR and PH. Compared with the standard treatment of 1 x 25 Gy, fractionation with 5 x 5 Gy was equally efficacious, the Mann-Whitney U test disclosing no statistically significant difference (p = 0.146). The lower doses of 1 x 5 Gy, 1 x 8 Gy, and 5 x 2 Gy were significantly less effective with p < 0.05. Conclusion: This study suggests that fractionated radiotherapy in combination with PH is a conceivable pretreatment approach to prime the host liver for hepatocyte transplantation, thus

  7. Immunologic changes after loco-regional radiotherapy and fractionated total body irradiation (TBI) in mice

    The immunologic effects of fractionated irradiation to both hind limbs and the tail of adult mice were investigated. A dose of 34 Gy given in 17 fractions of 2 Gy, 1 fraction per day, 5 days per week, was delivered with a 60Co source. A significant decrease of the total splenocyte count and of the PHA(phytohemagglutinin)-induced proliferation of T cells was found immediately after irradiation. Both parameters normalized within 30 days after irradiation. Immediately after irradiation, the MLC (mixed lymphocyte culture) was supranormal, dropped to 45% 1 week later, and normalized within 1 month after radiotherapy. The NK (natural killer) activity was significantly decreased only the first week after loco-regional irradiation, while the LAK (lymphokine activated killer) activity was not altered at all. The percentage of goat-anti-mouse+ cells (mainly B lymphocytes) was not changed immediately after loco-regional irradiation, but rose to supranormal values (175% of control level) 3 months after irradiation. A persistent decrease of the percentage and the absolute numbers of the Lyt2+ cells (= CD8+ cells, suppressor/cytotoxic phenotype) was observed up to 3 months after irradiation, while the percentage of L3T4+ cells (= CD4+ cells, helper phenotype) remained normal for the total follow-up. No differences in allogeneic skin graft survival could be demonstrated between irradiated and control animals. The observed immunological effects could not be explained by the scatter irradiation to the whole body as total body irradiation (TBI) administered in a dose and dose rate similar to the scatter dose did not result in persistent immunologic changes. No dose-rate effect could be demonstrated in a low dose fractionated total body irradiation schedule. A total body irradiation similar to the scatter dose in humans did not result in significant immunologic changes

  8. A comparison of 3-D data correlation methods for fractionated stereotactic radiotherapy

    Purpose: Stereotactic radiosurgery is currently used to treat patients who are not good candidates for conventional neurosurgical procedures. For treatments of nonvascular tumor cells, it appears that fractionation offers a radiobiological advantage between tumor and normal tissues. Therefore, fractionated stereotactic radiotherapy (FSR) is preferred because it minimizes normal tissue complications and maximizes local tumor control probability. We have implemented a methodology clinically to perform the noninvasive patient repositioning technique. The 3-D data correlation method for high-precision and multiple fraction stereotactic treatments has been presented. Methods and Materials: Three different optimization algorithms (Hooke and Jeeves optimization, simplex optimization, and simulated annealing optimization) are evaluated to calculate the transformation parameters necessary for FSR. A least-square object function is created to perform the 3-D data matching process. By minimizing the unconstrained object function value the best fit can be approached for the reference 3-D data sets. Simulation shows that these algorithms deliver results that are comparable to the previously published correlation algorithm (singular value decomposition [SVD] method). The advantage for optimization algorithms is easily understood and can be readily implemented by using a personal computer (PC). The mathematical framework provides a tool to calculate the transformation matrix which can be used to adjust patient position for fractionated treatments. Therefore, using these algorithms for a high-precision fractionated treatment is possible without an invasive repeat fixation device and has been implemented clinically. A bite plate system was incorporated to acquire 3-D patient data. With a 3-D digital camera localization device, the patient motion can be followed in real time with the system calibrated to the isocenter. Results: Two types of data sets are utilized to study the

  9. A real time scintillating fiber dosimeter for gamma and neutron monitoring on radiotherapy accelerators

    Bartesaghi, G. [INFN Sez. di Milano and Universita dell' Insubria, Como (Italy)]. E-mail: giacomobartesaghi@libero.it; Conti, V. [INFN Sez. di Milano and Universita dell' Insubria, Como (Italy); Prest, M. [INFN Sez. di Milano and Universita dell' Insubria, Como (Italy); Mascagna, V. [Universita dell' Insubria, Como (Italy); Scazzi, S. [Universita dell' Insubria, Como (Italy); Cappelletti, P. [Ospedale Sant' Anna, Como (Italy); Frigerio, M. [Ospedale Sant' Anna, Como (Italy); Gelosa, S. [Ospedale Sant' Anna, Como (Italy); Monti, A. [Ospedale Sant' Anna, Como (Italy); Ostinelli, A. [Ospedale Sant' Anna, Como (Italy); Mozzanica, A. [INFN Sez. di Pavia and Universita di Brescia (Italy); Bevilacqua, R. [Universita di Trieste and INFN sez. di Trieste (Italy); Giannini, G. [Universita di Trieste and INFN sez. di Trieste (Italy); Totaro, P. [Universita di Trieste and INFN sez. di Trieste (Italy); Vallazza, E. [INFN Sez. di Trieste (Italy)

    2007-03-01

    The quality of the radiotherapic treatment depends strongly on the capability to measure the dose released in the treated volume and the one absorbed by the surrounding volumes, which is mainly due to the scattered radiation produced by the primary beam interaction with the accelerator collimating system. Radiotherapy linear accelerators produce electron (6-20MeV) and photon (6, 18MV) irradiating fields up to 40x40cm{sup 2}. Photons with energies greater than 8MeV generate neutrons via photoproduction which are being studied for possible BNCT applications. We have developed a prototype of a real time dosimeter with 1mm diameter scintillating and clear fibers readout by multianode photomultipliers. For neutron applications, the fibers have been coupled with boron loaded scintillator. We will describe the dosimeter and the results of the tests comparing them to the ones obtained with the standard dosimeters.

  10. Hypo-fractionated radiotherapy of breast cancer: long term results of a set of 80 cases treated in the radiotherapy department of the Oran university hospital

    The authors report the assessment of the local and locoregional control and of the acute and late toxicity of adjuvant hypo-fractionated radiotherapy in breast cancer treatment. During 1998, 80 women have been treated by conservative or radical surgery and hypo-fractionated tele-cobalto-therapy (36 Gy in five fractions of 3 Gy a week, and a boost of 15 Gy in five fractions in case of conservative surgery). Results are discussed in terms of local and locoregional recurrence, tolerance, late toxicity, global survival, and tumour classification. The irradiation scheme seems perfectly achievable but a greater number of patients and a longer follow-up are required to better assess the efficiency and aesthetic results. Short communication

  11. Evaluation of oxygenation status during fractionated radiotherapy in human nonsmall cell lung cancers using [F-18]fluoromisonidazole positron emission tomography

    Purpose: Recent clinical investigations have shown a strong correlation between pretreatment tumor hypoxia and poor response to radiotherapy. These observations raise questions about standard assumptions of tumor reoxygenation during radiotherapy, which has been poorly studied in human cancers. Positron emission tomography (PET) imaging of [F-18]fluoromisonidazole (FMISO) uptake allows noninvasive assessment of tumor hypoxia, and is amenable for repeated studies during fractionated radiotherapy to systematically evaluate changes in tumor oxygenation. Methods and Materials: Seven patients with locally advanced nonsmall cell lung cancers underwent sequential [F-18]FMISO PET imaging while receiving primary radiotherapy. Computed tomograms were used to calculate tumor volumes, define tumor extent for PET image analysis, and assist in PET image registration between serial studies. Fractional hypoxic volume (FHV) was calculated for each study as the percentage of pixels within the analyzed imaged tumor volume with a tumor:blood [F-18]FMISO ratio ≥ 1.4 by 120 min after injection. Serial FHVs were compared for each patient. Results: Pretreatment FHVs ranged from 20-84% (median 58%). Subsequent FHVs varied from 8-79% (median 29%) at midtreatment, and ranged from 3-65% (median 22%) by the end of radiotherapy. One patient had essentially no detectable residual tumor hypoxia by the end of radiation, while two others showed no apparent decrease in serial FHVs. There was no correlation between tumor size and pretreatment FHV. Conclusions: Although there is a general tendency toward improved oxygenation in human tumors during fractionated radiotherapy, these changes are unpredictable and may be insufficient in extent and timing to overcome the negative effects of existing pretreatment hypoxia. Selection of patients for clinical trials addressing radioresistant hypoxic cancers can be appropriately achieved through single pretreatment evaluations of tumor hypoxia

  12. Hyperfractionated-accelerated radiotherapy followed by radical surgery in locally advanced tumors of the oral cavity

    Hoeller, U. [Dept. of Radiotherapy, Radiooncology and Nuclear Medicine, Vivantes Klinikum Neukoelln, Berlin (Germany); Biertz, I.; Tribius, S.; Alberti, W. [Dept. of Radiotherapy and Radiooncology, Univ. Hospital Hamburg-Eppendorf (Germany); Flinzberg, S.; Schmelzle, R. [Dept. of Dental, Oral and Maxillofacial Surgery, Univ. Hospital Hamburg-Eppendorf (Germany)

    2006-03-15

    Purpose: to evaluate the outcome of hyperfractionated-accelerated radiotherapy and subsequent planned primary tumor resection and radical neck dissection in locally advanced tumors of the oral cavity. Patients and Methods: this retrospective analysis evaluates 126 subsequent patients who were treated between 1988 and 1997 for locally advanced tumors of the oral cavity (with extension into the oropharynx in 17 patients), 34 (27%) AJCC stage III and 92 (73%) stage IV. Primary tumor and nodal metastases were irradiated with 1.4 Gy bid to a median total dose of 72.8 Gy (range 58.8-75.6 Gy). Then, planned radical surgery of the primary site according to the initial tumor extent and cervical nodes was performed. Median follow-up of living patients was 6 years (range 1-11 years). Results: 4 weeks after radiotherapy, 14 patients (11%) had complete tumor remission, 92 (73%) partial remission, 15 (12%) no change, and five (4%) progressive disease. Complete resection was achieved in 117 (93%) patients (nine incomplete resections). 5-year locoregional control rate was 62 {+-} 9%, overall survival 36 {+-} 9%. Surgery-related morbidity occurred in 42 patients (33%; mainly delayed wound healing and fistulae), overall severe treatment-related morbidity in 46 patients (36%). 24/84 relapse-free patients (29%) required a percutaneous gastrostomy or nasal tube {>=} 1 year after therapy. Conclusion: in this study, the outcome of combined curative radiotherapy and planned surgery of the primary tumor and neck nodes was comparable to reported results of hyperfractionated radiotherapy with or without salvage surgery of the neck nodes with respect to locoregional control and overall survival. Planned surgery carries a substantial risk of morbidity and seems to offer no benefit in comparison to salvage surgery of the neck nodes only. Therefore, salvage surgery is preferred. (orig.)

  13. Vertical mammaplasty associated with accelerated partial breast radiotherapy: how oncoplastic surgery techniques associated with modern techniques of radiotherapy can improve the aesthetic outcome in selected patients

    Breast cancer is the second most common type of cancer in the world, being the most common among women, responsible for 22% of new cases each year. It's surgical and radiation treatment evolved from radical procedures (Halsted radical mastectomy and total external breast radiotherapy) to less radical and more conservative procedures. With the use of modern oncoplastic surgery techniques and accelerated partial breast radiotherapy, selected patients can benefit with better aesthetic results, fewer side effects, and more comfortable and brief treatments. (author)

  14. Vertical mammaplasty associated with accelerated partial breast radiotherapy: how oncoplastic surgery techniques associated with modern techniques of radiotherapy can improve the aesthetic outcome in selected patients

    Couto, Henrique Lima, E-mail: enriquecouto@hotmail.com [Santa Fe Women' s and Maternity Hospital, Belo Horizonte, MG (Brazil); Amorim, Washington Cancado; Guimaraes, Rodrigo [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Hospital Geral; Ramires, Leandro Cruz; Castilho, Marcus Simoes [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Medicina; Dominguez, Lorena Lima Coto [Universidade Estacio de Sa (UNESA), Rio de Janeiro, EJ (Brazil)

    2014-07-15

    Breast cancer is the second most common type of cancer in the world, being the most common among women, responsible for 22% of new cases each year. It's surgical and radiation treatment evolved from radical procedures (Halsted radical mastectomy and total external breast radiotherapy) to less radical and more conservative procedures. With the use of modern oncoplastic surgery techniques and accelerated partial breast radiotherapy, selected patients can benefit with better aesthetic results, fewer side effects, and more comfortable and brief treatments. (author)

  15. Medication for hearing loss after fractionated stereotactic radiotherapy (SRT) for vestibular schwannoma

    Purpose: To investigate the effectiveness of corticosteroid treatments for patients showing decreases in hearing levels after stereotactic radiotherapy for vestibular schwannoma. Methods and Materials: Twenty-one patients experienced a hearing loss in pure-tone average at greater than 20 dB or less than 10 dB within 1 year after irradiation administration of 44 Gy/22 fractions followed by a 4 Gy boost. Eight received oral prednisone at a daily dose of 30 mg, which was gradually decreased (medicated group), and 13 received none (nonmedicated group). The average observation period was 26.7±16.6 (range: 6-69) months. Results: Hearing recovery was seen after initial onset of the hearing loss in all 8 patients in the medicated group and in 2 of 13 patients in the nonmedicated group (p=0.001). The hearing recovery, that is, the change in pure-tone average (dB) at the last follow-up from the onset of hearing loss, was 9.8±6.9 dB (recovery) in the medicated group and -9.4±12.8 dB (further loss) in the nonmedicated group (p=0.0013). The hearing recovery rate, normalizing to the degree of the hearing loss before medication, was also significantly higher in the medicated group than in the nonmedicated group (p=0.0014). Conclusions: Corticosteroidal intake is suggested to be effective in improving hearing loss after stereotactic radiotherapy, at least in young patients having a useful pretreatment hearing level, if the treatment for hearing loss is administered immediately after the hearing loss is first detected

  16. SU-E-J-187: Management of Optic Organ Motion in Fractionated Stereotactic Radiotherapy

    Purpose: Fractionated stereotactic radiotherapy (FSRT) for optic nerve tumors can potentially use planning target volume (PTV) expansions as small as 1–5 mm. However, the motion of the intraorbital segment of the optic nerve has not been studied. Methods: A subject with a right optic nerve sheath meningioma underwent CT simulation in three fixed gaze positions: right, left, and fixed forward at a marker. The gross tumor volume (GTV) and the organs-at-risk (OAR) were contoured on all three scans. An IMRT plan using 10 static non-coplanar fields to 50.4 Gy in 28 fractions was designed to treat the fixed-forward gazing GTV with a 1 mm PTV, then resulting coverage was evaluated for the GTV in the three positions. As an alternative, the composite structures were computed to generate the internal target volume (ITV), 1 mm expansion free-gazing PTV, and planning organat-risk volumes (PRVs) for free-gazing treatment. A comparable IMRT plan was created for the free-gazing PTV. Results: If the patient were treated using the fixed forward gaze plan looking straight, right, and left, the V100% for the GTV was 100.0%, 33.1%, and 0.1%, respectively. The volumes of the PTVs for fixed gaze and free-gazing plans were 0.79 and 2.21 cc, respectively, increasing the PTV by a factor of 2.6. The V100% for the fixed gaze and free-gazing plans were 0.85 cc and 2.8 cc, respectively increasing the treated volume by a factor of 3.3. Conclusion: Fixed gaze treatment appears to provide greater organ sparing than free-gazing. However unanticipated intrafraction right or left gaze can produce a geometric miss. Further study of optic nerve motion appears to be warranted in areas such as intrafraction optical confirmation of fixed gaze and optimized gaze directions to minimize lens and other normal organ dose in cranial radiotherapy

  17. A Phase I Study of Chemoradiotherapy With Use of Involved-Field Conformal Radiotherapy and Accelerated Hyperfractionation for Stage III Non-Small Cell Lung Cancer: WJTOG 3305

    Tada, Takuhito, E-mail: tada@msic.med.osaka-cu.ac.jp [Department of Radiology, Osaka City University Graduate School of Medicine, Osaka (Japan); Department of Radiology, Izumi Municipal Hospital, Izumi (Japan); Chiba, Yasutaka [Department of Environmental Medicine and Behavioural Science, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Tsujino, Kayoko [Department of Radiation Oncology, Hyogo Cancer Center, Akashi (Japan); Fukuda, Haruyuki [Department of Radiology, Osaka Prefectural Medical Center for Respiratory and Allergic Diseases, Habikino (Japan); Nishimura, Yasumasa [Department of Radiation Oncology, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Kokubo, Masaki [Division of Radiation Oncology, Institute of Biomedical Research and Innovation, Kobe (Japan); Negoro, Shunichi [Department of Medical Oncology, Hyogo Cancer Center, Akashi (Japan); Kudoh, Shinzoh [Department of Respiratory Medicine, Osaka City University Graduate School of Medicine, Osaka (Japan); Fukuoka, Masahiro [Department of Medical Oncology, Izumi Municipal Hospital, Izumi (Japan); Nakagawa, Kazuhiko [Department of Medical Oncology, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Nakanishi, Yoichi [Research Institute for Disease of the Chest, Graduate School of Medical Science, Kyusyu University, Fukuoka (Japan)

    2012-05-01

    Purpose: A Phase I study to determine a recommended dose of thoracic radiotherapy using accelerated hyperfractionation for unresectable non-small-cell lung cancer was conducted. Methods and Materials: Patients with unresectable Stage III non-small-cell lung cancer were treated intravenously with carboplatin (area under the concentration curve 2) and paclitaxel (40 mg/m{sup 2}) on Days 1, 8, 15, and 22 with concurrent twice-daily thoracic radiotherapy (1.5 Gy per fraction) beginning on Day 1 followed by two cycles of consolidation chemotherapy using carboplatin (area under the concentration curve 5) and paclitaxel (200 mg/m{sup 2}). Total doses were 54 Gy in 36 fractions, 60 Gy in 40 fractions, 66 Gy in 44 fractions, and 72 Gy in 48 fractions at Levels 1 to 4. The dose-limiting toxicity, defined as Grade {>=}4 esophagitis and neutropenic fever and Grade {>=}3 other nonhematologic toxicities, was monitored for 90 days. Results: Of 26 patients enrolled, 22 patients were assessable for response and toxicity. When 4 patients entered Level 4, enrollment was closed to avoid severe late toxicities. Dose-limiting toxicities occurred in 3 patients. They were Grade 3 neuropathy at Level 1 and Level 3 and Grade 3 infection at Level 1. However, the maximum tolerated dose was not reached. The median survival time was 28.6 months for all patients. Conclusions: The maximum tolerated dose was not reached, although the dose of radiation was escalated to 72 Gy in 48 fractions. However, a dose of 66 Gy in 44 fractions was adopted for this study because late toxicity data were insufficient.

  18. A Phase I Study of Chemoradiotherapy With Use of Involved-Field Conformal Radiotherapy and Accelerated Hyperfractionation for Stage III Non-Small Cell Lung Cancer: WJTOG 3305

    Purpose: A Phase I study to determine a recommended dose of thoracic radiotherapy using accelerated hyperfractionation for unresectable non–small-cell lung cancer was conducted. Methods and Materials: Patients with unresectable Stage III non–small-cell lung cancer were treated intravenously with carboplatin (area under the concentration curve 2) and paclitaxel (40 mg/m2) on Days 1, 8, 15, and 22 with concurrent twice-daily thoracic radiotherapy (1.5 Gy per fraction) beginning on Day 1 followed by two cycles of consolidation chemotherapy using carboplatin (area under the concentration curve 5) and paclitaxel (200 mg/m2). Total doses were 54 Gy in 36 fractions, 60 Gy in 40 fractions, 66 Gy in 44 fractions, and 72 Gy in 48 fractions at Levels 1 to 4. The dose-limiting toxicity, defined as Grade ≥4 esophagitis and neutropenic fever and Grade ≥3 other nonhematologic toxicities, was monitored for 90 days. Results: Of 26 patients enrolled, 22 patients were assessable for response and toxicity. When 4 patients entered Level 4, enrollment was closed to avoid severe late toxicities. Dose-limiting toxicities occurred in 3 patients. They were Grade 3 neuropathy at Level 1 and Level 3 and Grade 3 infection at Level 1. However, the maximum tolerated dose was not reached. The median survival time was 28.6 months for all patients. Conclusions: The maximum tolerated dose was not reached, although the dose of radiation was escalated to 72 Gy in 48 fractions. However, a dose of 66 Gy in 44 fractions was adopted for this study because late toxicity data were insufficient.

  19. Intra-fractional uncertainties in cone-beam CT based image-guided radiotherapy (IGRT) of pulmonary tumors

    Purpose: Intra-fractional variability of tumor position and breathing motion was evaluated in cone-beam CT (CB-CT) based image-guided radiotherapy (IGRT) of pulmonary tumors. Materials and methods: Twenty-four patients (27 lesions: prim. NSCLC n = 6; metastases n = 21) were treated with stereotactic body radiotherapy (SBRT) (one to eight fractions). Prior to every treatment fraction (n = 66) and immediately after treatment a CB-CT was acquired. Patient motion, absolute drift and drift of the tumor relative to the bony anatomy were measured. Tumor motion was investigated based on the density distribution in the CB-CT. Results: Absolute intra-fractional drift (3D vector) of the tumor position was 2.8 mm ± 1.6 mm (mean ± SD), maximum 7.2 mm. Poor correlation between patient motion and absolute tumor drift was observed. Changes of the tumor position due to patient motion and due to drifts independently from the bony anatomy were of similar magnitude with 2.1 mm ± 1.4 mm and 2.3 mm ± 1.6 mm, respectively. No systematic increase or decrease of breathing motion was seen. The intra-fractional change of breathing motion was more than 2 mm and 3 mm in 39% and 16%, respectively. Conclusion: Intra-fractional tumor position and breathing motion were stable. In IGRT of pulmonary tumors we suggest an ITV-to-PTV margin of 5 mm to compensate intra-fractional changes

  20. ACUTE TOXICITY PROFILE AND COMPLIANCE TO ACCELERATED RADIOTHERAPY PLUS CARBOGEN AND NICOTINAMIDE FOR CLINICAL STAGE T2-4 LARYNGEAL CANCER : RESULTS OF A PHASE III RANDOMIZED TRIAL

    Janssens, Geert O.; Terhaard, Chris H.; Doornaert, Patricia A.; Bijl, Hendrik P.; van den Ende, Piet; Chin, Alim; Pop, Lucas A.; Kaanders, Johannes H.

    2012-01-01

    Purpose: To report the acute toxicity profile and compliance from a randomized Phase III trial comparing accelerated radiotherapy (AR) with accelerated radiotherapy plus carbogen and nicotinamide (ARCON) in laryngeal cancer. Methods and Materials: From April 2001 to February 2008, 345 patients with

  1. Acute toxicity profile and compliance to accelerated radiotherapy plus carbogen and nicotinamide for clinical stage T2-4 laryngeal cancer: results of a phase III randomized trial.

    Janssens, G.O.R.J.; Terhaard, C.H.J.; Doornaert, P.A.; Bijl, H.P.; Ende, P. van den; Chin, A.; Pop, L.A.M.; Kaanders, J.H.A.M.

    2012-01-01

    PURPOSE: To report the acute toxicity profile and compliance from a randomized Phase III trial comparing accelerated radiotherapy (AR) with accelerated radiotherapy plus carbogen and nicotinamide (ARCON) in laryngeal cancer. METHODS AND MATERIALS: From April 2001 to February 2008, 345 patients with

  2. Increased diffuse radiation fraction does not significantly accelerate plant growth

    Angert, Alon; Krakauer, Nir

    2010-05-01

    A recent modelling study (Mercado et al., 2009) claims that increased numbers of scattering aerosols are responsible for a substantial fraction of the terrestrial carbon sink in recent decades because higher diffuse light fraction enhances plant net primary production (NPP). Here we show that observations of atmospheric CO2 seasonal cycle and tree ring data indicate that the relation between diffuse light and NPP is actually quite weak on annual timescales. The inconsistency of these data with the modelling results may arise because the relationships used to quantify the enhancement of NPP were calibrated with eddy covariance measurements of hourly carbon uptake. The effect of diffuse-light fraction on carbon uptake could depend on timescale, since this effect varies rapidly as sun angle and cloudiness change, and since plants can respond dynamically over various timescales to change in incoming radiation. Volcanic eruptions, such as the eruption of Mount Pinatubo in 1991, provide the best available tests for the effect of an annual-scale increase in the diffuse light fraction. Following the Pinatubo Eruption, in 1992 and 1993, a sharp decrease in the atmospheric CO2 growth rate was observed. This could have resulted from enhanced plant carbon uptake. Mercado et al. (2009) argue that largely as a result of the (volcanic aerosol driven) increase in diffuse light fraction, NPP was elevated in 1992, particularly between 25° N-45° N where annual NPP was modelled to be ~0.8 PgC (~10%) above average. In a previous study (Angert et al., 2004) a biogeochemical model (CASA) linked to an atmospheric tracer model (MATCH), was used to show that a diffuse-radiation driven increase in NPP in the extratropics will enhance carbon uptake mostly in summer, leading to a lower CO2 seasonal minimum. Here we use a 'toy model' to show that this conclusion is general and model-independent. The model shows that an enhanced sink of 0.8 PgC, similar to that modelled by Mercado et al. (2009

  3. Neuropsychological outcome after fractionated stereotactic radiotherapy (FSRT) for base of skull meningiomas: a prospective 1-year follow-up

    Purpose: The purpose of this study was to evaluate the cognitive outcome after fractionated stereotactic radiotherapy (FSRT) in patients with base of skull meningiomas. Methods and material: A total of 40 patients with base of skull meningiomas were neuro psychologically evaluated before, after the first fraction (1.8 Gy), at the end of FSRT (n=37), 6 weeks (n=24), 6 (n=18) and 12 months (n=14) after FSRT. A comprehensive test battery including assessment of general intelligence, attention and memory functions was used. Alternate forms were used and current mood state was controlled. Results: After the first fraction a transient decline in memory function and simultaneous improvements in attention functions were observed. No cognitive deteriorations were seen during further follow-up, but increases in attention and memory functions were observed. Mood state improved after the first fraction, at the end of radiotherapy and 6 weeks after radiotherapy. Conclusion: The present data support the conclusion that the probability for the development of permanent cognitive dysfunctions appears to be very low after FSRT. The transient memory impairments on day 1 are interpreted as most likely related to an increase of a preexisting peritumoral edema, whereas the significant acute improvements in attention functions are interpreted as practice effects. An analysis of localization specific effects of radiation failed to show clear hemisphere specific cognitive changes

  4. Compliance to the prescribed dose and overall treatment time in five randomized clinical trials of altered fractionation in radiotherapy for head-and-neck carcinomas

    Purpose: To investigate compliance to the prescribed dose-fractionation schedule in five randomized controlled trials of altered fractionation in radiotherapy for head-and-neck carcinoma. Methods and Materials: Individual patient data from 2566 patients participating in the European Organization for Research and Treatment of Cancer (EORTC) 22791, EORTC 22811, EORTC 22851, Princess Margaret Hospital (PMH), and continuous hyperfractionated accelerated radiotherapy (CHART) head-and-neck trials were merged in the fractionation IMPACT (Intergroup Merger of Patient data from Altered or Conventional Treatment schedules) study database. The ideal treatment time was defined as the minimum time required to deliver a prescribed schedule. Compliance to the prescribed overall treatment time was quantified as the difference between the actual and the ideal overall time. An overall measure of compliance in an individual patient, the total dose lost (TDL), was calculated as the dose lost due to prolongation of therapy (assuming a Dprolif of 0.64 Gy/day) plus the difference between the prescribed and the actual dose given. Results: The time in excess of the ideal ranged up to 97 days (average 3.9 days), and 25% of the patients had delays of 6 days or more. World Health Organization (WHO) performance status and nodal stage had a significant effect on TDL. TDL was significantly higher in the conventional than in the altered arm of the EORTC 22851 and CHART trials. In the PMH trial, TDL was significantly higher in the hyperfractionation than in the conventional arm. Centers participating in the three EORTC trials varied significantly in their compliance. There was a significant improvement in compliance in patients treated more recently. Conclusions: Even in randomized controlled trials, compliance to the prescribed radiation therapy schedule may be relatively poor, especially after conventional fractionation. This affects the interpretation of the outcome of these trials

  5. Extracranial doses during stereotactic radiosurgery and fractionated stereotactic radiotherapy measured with thermoluminescent dosimeter in vivo

    Kim, I.H.; Lim, D.H.; Kim, S.; Hong, S.; Kim, B.K.; Kang, W-S.; Wu, H.G.; Ha, S.W.; Park, C.I. [Seoul National University College of Medicine, Department of Therapeutic Radiology (Korea)

    2000-05-01

    Recently the usage of 3-dimensional non-coplanar radiotherapy technique is increasing. We measured the extracranial dose and its distribution g the above medical procedures to estimate effect of exit doses of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) of the intracranial target lesions using a linac system developed in our hospital. Among over hundred patients who were treated with SRS or FSRT from 1995 to 1998, radiation dosimetry data of 15 cases with SRS and 20 cases with FSRT were analyzed. All patients were adults. Of SRS cases, 11 were male and 4 were female. Vascular malformation cases were 9, benign tumors were 3, and malignant tumors were 3. Of FSRT cases, males were 12 and females were 8. Primary malignant brain tumors were 5, benign tumors were 6, and metastatic brain tumors were 10. Doses were measured with lithium fluoride TLD chips (7.5% Li-6 and 92.5% Li-7; TLD-100, Harshaw/Filtrol, USA). The chips were attached patient's skin at the various extracranial locations during SRS or FSRT. For SRS, 14-25 Gy were delivered with 1-2 isocenters using 12-38 mm circular tertiary collimators with reference to 50-80% isodose line conforming at the periphery of the target lesions. For FSRT, 5-28 fractions were used to deliver 9-56 Gy to periphery with dose maximum of 10-66 Gy. Both procedures used 6 MV X-ray generated from Clinac-18 (Varian, USA). For SRS procedures, extracranial surface doses (relative doses) were 8.07{+-}4.27 Gy (0.31{+-}0.16% Mean{+-}S.D.) at the upper eyelids, 6.13{+-}4.32 Gy (0.24{+-}0.16%) at the submental jaw, 7.80{+-}5.44 Gy (0.33{+-}0.26%) at thyroid, 1.78{+-}0.64 Gy (0.07{+-}0.02%) at breast, 0.75{+-}0.38 Gy (0.03{+-}0.02%) at umbilicus, 0.40{+-}0.07 Gy (0.02{+-}0.01%) at perineum, and 0.46{+-}0.39 Gy (0.02{+-}0.01%) at scrotum. Thus the farther the distance from the brain, the less the dose to the location. In overall the doses were less than 0.3% and thus less detrimental. For FSRT procedures

  6. Extracranial doses during stereotactic radiosurgery and fractionated stereotactic radiotherapy measured with thermoluminescent dosimeter in vivo

    Recently the usage of 3-dimensional non-coplanar radiotherapy technique is increasing. We measured the extracranial dose and its distribution g the above medical procedures to estimate effect of exit doses of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) of the intracranial target lesions using a linac system developed in our hospital. Among over hundred patients who were treated with SRS or FSRT from 1995 to 1998, radiation dosimetry data of 15 cases with SRS and 20 cases with FSRT were analyzed. All patients were adults. Of SRS cases, 11 were male and 4 were female. Vascular malformation cases were 9, benign tumors were 3, and malignant tumors were 3. Of FSRT cases, males were 12 and females were 8. Primary malignant brain tumors were 5, benign tumors were 6, and metastatic brain tumors were 10. Doses were measured with lithium fluoride TLD chips (7.5% Li-6 and 92.5% Li-7; TLD-100, Harshaw/Filtrol, USA). The chips were attached patient's skin at the various extracranial locations during SRS or FSRT. For SRS, 14-25 Gy were delivered with 1-2 isocenters using 12-38 mm circular tertiary collimators with reference to 50-80% isodose line conforming at the periphery of the target lesions. For FSRT, 5-28 fractions were used to deliver 9-56 Gy to periphery with dose maximum of 10-66 Gy. Both procedures used 6 MV X-ray generated from Clinac-18 (Varian, USA). For SRS procedures, extracranial surface doses (relative doses) were 8.07±4.27 Gy (0.31±0.16% Mean±S.D.) at the upper eyelids, 6.13±4.32 Gy (0.24±0.16%) at the submental jaw, 7.80±5.44 Gy (0.33±0.26%) at thyroid, 1.78±0.64 Gy (0.07±0.02%) at breast, 0.75±0.38 Gy (0.03±0.02%) at umbilicus, 0.40±0.07 Gy (0.02±0.01%) at perineum, and 0.46±0.39 Gy (0.02±0.01%) at scrotum. Thus the farther the distance from the brain, the less the dose to the location. In overall the doses were less than 0.3% and thus less detrimental. For FSRT procedures, dose ranged 1.7 to 4.0 Gy in the

  7. Effects of conventional fractionated three dimensional conformal radiotherapy on unresectable hepatocellular carcinoma

    Objective: To investigate the efficacy and toxicity of conventional fractionated three-dimensional conformal radiotherapy (3D-CRT) on unresectable hepatocellular carcinoma(HCC). Methods: Fifty two patients with unresectable HCC, all without extrahepatic metastases, were treated by 3D-CRT conducted 5 times a week with the total radiation dose of 36-66 Gy and a daily dose of 2 Gy. The curative effect was evaluated by CT scan to observe the maximum tumor size. Survival rates,survival time, and adverse responses were recorded. Results: The total effective rate of the 52 patients was 69.2% with complete response (CR) in 2 patients and partial response (PR) in 34 patients. The incidence rate of radioactive hepatitis was 1.92%. The 1-, 2-, 3-, and 4-year survival rates were 57.7%, 34.6%, 23.1%, and 9.61% respectively, and the median survival time was 10.5 months. The 1-, 2-, 3-, and 4-year local control rates were 67%, 51.5%, 32.3%, and 2.24%, and the 1-, 2-, 3-, and 4-year distant metastasis rate were 17.2%, 23.5%, 36.7%, and 76.9% respectively. The intrahepatic metastases rate was 62.5% and 37.5% of the patients suffered from extrahepatic metastasis, including metastases of lung,bone,and retroperitoneal lymph nodes. The remission rate of the ≥50 Gy group was 76.9%, significantly higher than that of the ≤50 Gy group (46.2%, χ2=10.72, P<0.05).There was no grade 3 or 4 acute toxicity, and two patients (3.84%) developed gastric or duodenal ulcer. Conclusions: Conventional fractionated 3D-CRT evokes a rather effective response for unresectable HCC with acceptable toxicity. Radiation dose seems to be a significant prognostic factor in RT response for HCC. (authors)

  8. A prospective trial of short-fractionation radiotherapy for the palliation of liver metastases

    The purpose of this study was to prospectively examine the effectiveness and tolerability of a simple radiotherapy technique for the palliation of symptomatic liver metastases. Twenty-eight patients with symptomatic liver metastases were enrolled from seven centres, and received targeted (partial or whole) liver irradiation consisting of 10 Gy in two fractions over 2 days. Symptoms at baseline were hepatic pain (27 patients), abdominal distension (19), night sweats (12), nausea (18) and vomiting (eight). Twenty-two patients (76%) had failed previous treatment with chemotherapy, hormonal therapy and/or high-dose steroids. Symptoms and potential toxicities were prospectively assessed at the time of treatment, then 2, 6 and 10 weeks later. Individual symptom response rates were 53-66% at 2 weeks. Partial or complete global symptomatic responses were noted in 15 patients (54%) overall. The treatment was well tolerated with two patients (7%) experiencing grade 3 toxicity (one vomiting and one diarrhoea); however, four patients reported temporary worsening of pain shortly after treatment. This simple and well-tolerated treatment achieves useful palliation. Copyright (2003) Blackwell Science Pty Ltd

  9. Can exhaled NO fraction predict radiotherapy-induced lung toxicity in lung cancer patients?

    A large increase in nitric oxide fraction (FeNO) after radiotherapy (RT) for lung cancer may predict RT-induced lung toxicity. In this study, we assessed the relationships between FeNO variations and respiratory symptoms, CT scan changes or dose volume histogram (DVH) parameters after RT. We measured FeNO before RT, 4, 5, 6, 10 weeks, 4 and 7.5 months after RT in 65 lung cancer patients. Eleven lung cancer patients (17%) complained of significant respiratory symptoms and 21 (31%) had radiation pneumonitis images in >1/3 of the irradiated lung after RT. Thirteen patients (20%) showed increases in FeNO >10 ppb. The sensitivity and specificity of a >10 ppb FeNO increase for the diagnosis of RT-associated respiratory symptoms were 18% and 83%, respectively. There was no correlation between DVH parameters or CT scan changes after RT and FeNO variations. Three patients (5%) showed intriguingly strong (2 or 3-fold, up to 55 ppb) and sustained increases in FeNO at 4 and 5 weeks, followed by significant respiratory symptoms and/or radiation-pneumonitis images. Serial FeNO measurements during RT had a low ability to identify lung cancer patients who developed symptoms or images of radiation pneumonitis. However, three patients presented with a particular pattern which deserves to be investigated

  10. In vivo cell kinetic measurements in a randomized trial of continuous hyperfractionated accelerated radiotherapy with or without mitomycin C in head-and-neck cancer

    Purpose: Tumor cell repopulation is still considered to be a major cause of failure in radiotherapy. In this study, we investigated the influence of cell kinetic parameters on the outcome of patients treated in a randomized trial of accelerated fractionation, with or without mitomycin C, vs. conventional fractionation. Methods and Materials: Sixty-two patients were studied using administration of bromodeoxyuridine (BrdUrd), and cell kinetic parameters were measured using flow cytometry. The patients were treated with either 70 Gy for 7 weeks or 55.3 Gy for 17 continuous days (V-CHART) with or without 20 mg/m2 mitomycin C on day 5. Results: The potential doubling time (Tpot) and labeling index (LI) failed to provide any prognostic information with regard to local control or survival. However, the duration of the S phase (Ts) revealed patients whose tumors had a long Ts had significantly worse local control (p = 0.028) and survival (p = 0.034) irrespective of treatment. A similar trend was evident within the different treatment arms particularly associated with overall survival. Conclusions: The Ts values of head-and-neck squamous cell cancers provided prognostic information that predicted clinical outcome irrespective of treatment schedule in this study. This neglected parameter of the Tpot method might provide information related to redistribution of cells during fractionated radiotherapy

  11. Accelerated superfractionated radiotherapy for inflammatory breast carcinoma: complete response predicts outcome and allows for breast conservation

    Purpose: Chemotherapy and accelerated superfractionated radiotherapy were prospectively applied for inflammatory breast carcinoma with the intent of breast conservation. The efficacy, failure patterns, and patient tolerance utilizing this approach were analyzed. Methods and Materials: Between 1983 and 1996, 52 patients with inflammatory breast carcinoma presented to the Medical College of Virginia Hospitals of VCU and the New England Medical Center. Thirty-eight of these patients were jointly evaluated in multidisciplinary breast clinics and managed according to a defined prospectively applied treatment policy. Patients received induction chemotherapy, accelerated superfractionated radiotherapy, selected use of mastectomy, and concluded with additional chemotherapy. The majority were treated with 1.5 Gy twice daily to field arrangements covering the entire breast and regional lymphatics. An additional 18-21 Gy was then delivered to the breast and clinically involved nodal regions. Total dose to clinically involved areas was 63-66 Gy. Following chemoradiotherapy, patients were evaluated with physical examination, mammogram, and fine needle aspiration x 3. Mastectomy was reserved for those patients with evidence of persistent or progressive disease in the involved breast. All patients received additional chemotherapy. Results: Median age was 51 years. Median follow-up was 23.9 months (6-86) months. The breast preservation rate at the time of last follow-up was 74%. The treated breast or chest wall as the first site of failure occurred in only 13%, and the ultimate local control rate with the selected use of mastectomy was 74%. Ten patients underwent mastectomy, 2 of which had pathologically negative specimens despite a clinically palpable residual mass. Response to chemotherapy was predictive of treatment outcome. Of the 15 patients achieving a complete response, 87% remain locoregionally controlled without the use of mastectomy. Five-year overall survival for

  12. Quality of life in patients with oropharynx carcinomas: assessment after accelerated radiotherapy with or without chemotherapy versus radical surgery and postoperative radiotherapy

    Allal, Abdelkarim Said; Nicoucar, Kevin; Mach, Nicolas; Dulguerov, Pavel

    2003-01-01

    In oropharyngeal carcinomas, it is assumed that the effectiveness of the different treatment approaches is roughly equivalent, whereas the functional outcome after radical radiotherapy (RT) is superior to that associated with primary surgery. The aim of this study is to assess quality of life (QoL) outcomes of patients after two treatment strategies: radical surgery with postoperative RT and accelerated concomitant boost RT with or without chemotherapy.

  13. Radiotherapy

    The book is focussed on the actual knowledge on the clinical radiotherapy and radio-oncology. Besides fundamental and general contributions specific organ systems are treated in detail. The book contains the following contributions: Basic principles, radiobiological fundamentals, physical background, radiation pathology, basics and technique of brachytherapy, methodology and technique of the stereotactic radiosurgery, whole-body irradiation, operative radiotherapy, hadron therapy, hpyerthermia, combined radio-chemo-therapy, biometric clinical studies, intensity modulated radiotherapy, side effects, oncological diagnostics; central nervous system and sense organs, head-neck carcinomas, breast cancer, thorax organs, esophagus carcinoma, stomach carcinoma, pancreas carcinoma, heptabiliary cancer and liver metastases, rectal carcinomas, kidney and urinary tract, prostate carcinoma, testicular carcinoma, female pelvis, lymphatic system carcinomas, soft tissue carcinoma, skin cancer, bone metastases, pediatric tumors, nonmalignant diseases, emergency in radio-oncology, supporting therapy, palliative therapy

  14. Preoperative concurrent CBDCA chemotherapy and accelerated hyperfractionated radiotherapy for squamous cell carcinoma of the maxillary region

    Between 1994 and 2000, 28 patients with T3/T4 squamus cell carcinoma of the maxillary region (maxillary sinus, 22; maxillary gingiva, 4; maxillary bone, 1; buccal mucosa, 1) had accelerated hyperfractionated radiotherapy combined with simultaneous CBDCA chemotherapy preoperatively, at Chiba Cancer Center Hospital. The protocol consisted of combined therapy with accelerated hyperfractionated irradiation of 1.6 Gy, twice a day, to a total dose of 32.0-51.2 Gy and concurrent intra-arterial or intravenous infusion of CBDCA 20-30 mg/body/day for a cumulative total dose of 270-480 mg. After completion of the preoperative combined therapy, the clinical CR rate was 17.9%, and the good PR·CR rate was 32.1%. According to the initial findings and response to the combined therapy, all patients had maxillectomy (subtotal, 3; total, 16; extended, 9) 4 weeks after completion of the preoperative combined therapy. Postoperatively, the complete pathologic response (Ohboshi and Shimozato's classification, grade III and IV) rate was 28.6%. And the actuarial local control rate was 85.7%, with a mean follow-up of 46.2 months. Based on these results, we believe this preoperative therapy with CBDCA chemotherapy and accelerated hyperfractionated radiation is a significant choice as treatment for squamous cell cancer of the maxillary region. (author)

  15. Salvage Fractionated Stereotactic Radiotherapy with or without Chemotherapy and Immunotherapy for Recurrent Glioblastoma Multiforme: A Single Institution Experience

    Hasan, Shaakir; Chen, Eda; Lanciano, Rachelle; Yang, Jun; Hanlon, Alex; Lamond, John; Arrigo, Stephen; Ding, William; Mikhail, Michael; Ghaneie, Arezoo; Brady, Luther

    2015-01-01

    Background The current standard of care for salvage treatment of glioblastoma multiforme (GBM) is gross total resection and adjuvant chemoradiation for operable patients. Limited evidence exists to suggest that any particular treatment modality improves survival for recurrent GBM, especially if inoperable. We report our experience with fractionated stereotactic radiotherapy (fSRT) with and without chemo/immunotherapy, identifying prognostic factors associated with prolonged survival. ...

  16. A comparison of 3-D data correlation methods for fractionated stereotactic radiotherapy (FSR)

    Purpose/Objective: Stereotactic Radiosurgery is currently used to treat patients who are not good candidates for conventional neurosurgical procedures. For treatments of nonvascular tumor cells, it appears that fractionation will offer a radiological advantage between tumor and normal tissues. Therefore, Fractionated Stereotactic Radiotherapy (FSR) is preferred because it minimizes normal tissue complications and maximizes local tumor control probability. We have implemented a methodology clinically to perform the non-invasive patient repositioning technique. The 3-D data correlation method for high precision and multiple fraction stereotactic treatments has been presented. Materials and Methods: Three different optimization algorithms (Hooke and Jeeves optimization, Simplex optimization, and Simulated Annealing optimization) are evaluated to calculate the transformation parameters necessary for FSR. These algorithms are based on rigid body transformation in which the patient surfaces are considered as reference. A least-square object function is created to perform the 3-D data matching process. By minimizing the unconstrained object function value the best fit can be approached for the reference 3-D data sets. Simulation shows that these algorithms give results which are comparable to the previously published correlation algorithm (Singular Value Decomposition (SVD) method). The advantage is that these algorithms are easily understood and can be readily implemented using a personal computer. The mathematical framework provides a tool to calculate the transformation matrix which can be used to adjust patient position for fractionated treatment. Therefore, using these algorithms for a high precision fractionated treatment is possible without invasive repeat fixation device. A bite plate system was incorporated to acquire 3-D patient data. With 3-D digital camera localization device, the patient motion can be followed in real time with the system calibrated to the

  17. Integration of surgery with fractionated stereotactic radiotherapy for treatment of nonfunctioning pituitary macroadenomas

    Objective: To evaluate the efficacy of fractionated stereotactic radiotherapy (FSRT) after surgery in the management of residual or recurrent nonfunctioning pituitary adenomas with respect to tumor control and the development of complications. Methods and materials: The clinical records of patients with nonfunctioning pituitary adenomas who underwent FSRT were retrospectively analyzed. For newly diagnosed tumors, transsphenoidal surgery was performed, and, if residual tumor was identified at 3 months, FSRT was performed. If significant tumor volume persisted, transcranial surgery was performed before FSRT. We originally initiated FSRT with 2-Gy fractions to 46 Gy. We escalated the dose to 50.4 Gy thereafter. As a final modification, we dropped the daily dose to 1.8-Gy fractions delivered within 6 weeks. High-dose conformality and homogeneity was achieved with arc beam shaping and differential beam weighting. The radiographic, endocrinologic, and visual outcomes after FSRT were evaluated. Results: The 68 patients included 36 males and 32 females with an age range of 15-81 years. The median follow-up was 30 months (range, 2-82 months), and the median tumor volume was 6.2 cm3. Of the 68 patients, 20 were treated to 46 Gy and 48 to 50-52.2 Gy. Most were treated to 50.4 Gy. Eleven patients had recurrent tumors, 54 had residual tumors, and no surgery was performed in 3 patients before FSRT. We noted no radiation-induced acute or late toxicities, except for radiation-induced optic neuropathy in 2 patients. At latest follow-up, the tumor had decreased in size in 26 patients and remained stable in 41 of the 42 remaining patients. Of the 68 patients, 4 (6%) developed hypopituitarism at 6, 11, 12, and 17 months after FSRT. Reviewing available serial Humphrey visual fields, visual fields were objectively improved in 28 patients, and remained stable in 24 patients, and worsened in 2 patients. Conclusion: The findings of this analysis support the use of surgery followed by FSRT

  18. Five compared with six fractions per week of conventional radiotherapy of squamous-cell carcinoma of head and neck: DAHANCA 6 and 7 randomised controlled trial

    Overgaard, Jens; Hansen, Hanne Sand; Specht, Lena; Overgaard, Marie; Grau, Cai; Andersen, Elo; Bentzen, Jens Knud Daugaard; Bastholt, Lars; Hansen, Olfred; Johansen, Jørgen; Andersen, Lisbeth; Evensen, Jan F

    2003-01-01

    Although head and neck cancer can be cured by radiotherapy, the optimum treatment time for locoregional control is unclear. We aimed to find out whether shortening of treatment time by use of six instead of five radiotherapy fractions per week improves the tumour response in squamous-cell carcinoma....

  19. Five compared with six fractions per week of conventional radiotherapy of squamous-cell carcinoma of head and neck: DAHANCA 6 and 7 randomised controlled trial

    Overgaard, Jens; Hansen, Hanne Sand; Specht, Lena;

    2003-01-01

    BACKGROUND: Although head and neck cancer can be cured by radiotherapy, the optimum treatment time for locoregional control is unclear. We aimed to find out whether shortening of treatment time by use of six instead of five radiotherapy fractions per week improves the tumour response in squamous-...

  20. Effectiveness of custom neutron shielding in the maze of radiotherapy accelerators

    An investigation was performed to examine the neutron dose equivalent in a radiotherapy maze lined with a customised neutron shielding material. The accelerator investigated was a Varian Clinac 2100C/D using 18 MV photons, and the neutron shielding utilised at this centre was PremadexTM commercially available neutron shielding. Based on Monte Carlo simulations, properly installed customised neutron shielding may reduce the neutron dose equivalent by up to a factor of 8 outside the maze, depending upon the installation. In addition, it was determined that the neutron dose near the entrance to the maze may be reduced by approximately 40% by using customised neutron shielding in the maze, as compared with a facility not using this shielding. This would have a positive dose-saving effect in doorless maze designs. (author)

  1. Accelerated hypofractionated radiation therapy compared to conventionally fractionated radiation therapy for the treatment of inoperable non-small cell lung cancer

    While conventionally fractionated radiation therapy alone is an acceptable option for poor prognostic patients with unresectable stage III NSCLC, we hypothesized that accelerated hypofractionated radiotherapy will have similar efficacy without increasing toxicity. This is a retrospective analysis of 300 patients diagnosed with stage III NSCLC treated between 1993 and 2009. Patients included in the study were medically or surgically inoperable, were free of metastatic disease at initial workup and did not receive concurrent chemotherapy. Patients were categorized into three groups. Group 1 received 45 Gy in 15 fractions over 3 weeks (Accelerated Radiotherapy (ACRT)) while group 2 received 60-63 Gy (Standard Radiation Therapy 1 (STRT1)) and group 3 received > 63 Gy (Standard Radiation Therapy (STRT2)). There were 119 (39.7%) patients in the ACRT group, 90 (30.0%) in STRT1 and 91 (30.3%) in STRT2. More patients in the ACRT group had KPS ≤ 60 (p < 0.001), more commonly presented with weight loss > 5% (p = 0.002), and had stage 3B disease (p < 0.001). After adjusting for clinical variables, there were no differences in the radiation groups in terms of the patterns of local or distant tumor control or overall survival. Some benefit in relapse free survival was seen in the STRT1 group as compared to ACRT (HR = 0.65, p = 0.011). Acute toxicity profiles in the ACRT were significantly lower for grade ≥ 2 radiation dermatitis (p = 0.002), nausea/vomiting (p = 0.022), and weight loss during treatment (p = 0.020). Despite the limitations of a retrospective analysis, our experience of accelerated hypofractionated radiation therapy with 45 Gy in 15 fractions appears to be an acceptable treatment option for poor performance status patients with stage III inoperable tumors. Such a treatment regimen (or higher doses in 15 fractions) should be prospectively evaluated using modern radiation technologies with the addition of sequential high dose chemotherapy in stage III NSCLC

  2. External beam radiotherapy for palliation of painful bone metastases: pooled data bioeffect dose response analysis of dose fractionation

    Bone metastases develop in up to 70% of newly diagnosed cancer patients and result in immobility, anxiety, and depression, severely diminishing the patients quality of life. Radiotherapy is a frequently used modality for bone metastasis and has been shown to be effective in reducing metastatic bone pain and in some instances, causing tumor shrinkage or growth inhibition. There is controversy surrounding the optimal fractionation schedule and total dose of external beam radiotherapy, despite many randomized trials and overviews addressing the issue. This study was undertaken to apply BED to clinical fractionation data of radiotherapeutic management of bone metastases in order to arrive at optimum BED values for acceptable level of response rate. A computerised literature search was conducted to identify all prospective clinical studies that addressed the issue of fractionation for the treatment of bone metastasis. The results of these studies were pooled together to form the database for the analysis. A total of 4111 number of patients received radiation dose ranging from 4 to 40.5 Gy in 1 to 15 fractions with dose per fraction ranging from 2 to 10 Gy. Single fraction treatments were delivered in 2013 patients and the dose varied from 4 to 10 Gy. Multi fraction treatments were delivered in 2098 patients and the dose varied from 15 to 40.5 Gy. The biological effective dose (BED) was evaluated for each fractionation schedule using the linear quadratic model and an / value of 10 Gy. Response rate increased significantly beyond a BED value of 14.4 Gy (p < 0.01). Based on our analysis and indications from the literature about higher retreatment and fracture rate of single fraction treatments, minimum BED value of 14.4 Gy is recommended. (authors)

  3. Impact on cellular immunocompetence by late course accelerated hyperfractionation radiotherapy assisted with cisplatin in the treatment of esophageal carcinoma

    Objective: To investigate the therapeutic results of late course accelerated hyperfractionation radiotherapy (LCAHR) combined with concomitant cisplatin administration as a sensitizer, and to assess the effects on cell-mediated immunocompetence in the treatment of esophageal carcinoma. Methods: From Jan. to Nov. 199, 104 patients with squamous cell carcinoma (SCC) of the esophagus were randomized to receive LCAHR alone (Group A, 53 patients) or LCAHR plus cisplatin (Group B, 51 patients). For both groups, the same radiation technic was given with the conventional fractionation in the first 3 weeks and 1.5 Gy twice daily, a minimum inter fraction interval of 6 hours, 5 days per week in the final 2 weeks. The total dose was 60 Gy/35 fs/5 wk. For the B group patients, cisplatin was given synchronously with 20 mg once daily for 5 days in the 1 st and 5 th weeks. The CD4, CD8 and CD56 expressions in peripheral blood lymphocytes (PBL) were quantitatively assessed with flow cytometry before and during the treatment. Results: The CD4/CD8 ratio of PBL decreased significantly after treatment completion (P < 0.01 in Group A and P < 0.01 in Group B). Whereas the percentage of positive CD56 PBL increased dramatically (P < 0.01 in two groups). There were no evidence that CD expression difference had any statistical or clinical significance. Conclusion: Immunosuppression may be present on cell-mediated immuno-activity (CD4/CD8) and NK cell (CD56)immuno-enhancement may be obtainable on immuno-surveillance, when esophageal carcinoma is being treated by LCAHR with or without cisplatin

  4. Neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer

    The purpose of this study was to examine the safety and feasibility of a novel protocol of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer. A total of 56 patients with lower rectal cancer of cT3N1M0 (Stage III b) was treated with SC-HART followed by radical surgery, and were analyzed in the present study. SC-HART was performed with a dose of 2.5 Gy twice daily, with an interval of at least 6 hours between fractions, up to a total dose of 25 Gy (25 Gy in 10 fractions for 5 days) combined with S-1 for 10 days. Radical surgery was performed within three weeks following the end of the SC-HART. The median age was 64.6 (range, 39-85) years. The median follow-up term was 16.3 (range, 2-53) months. Of the 56 patients, 53 (94.4%) had no apparent adverse events before surgery; 55 (98.2%) completed the full course of neoadjuvant therapy, while one patient stopped chemotherapy because of Grade 3 gastrointestinal toxicity (CTCAE v.3). The sphincter preservation rate was 94.6%. Downstaging was observed in 45 patients (80.4%). Adjuvant chemotherapy was administered to 43 patients (76.8%). The local control rate, disease-free survival rate and disease-specific survival rate were 100%, 91.1% and 100%, respectively. To conclude, SC-HART combined with S-1 for locally advanced rectal cancer was well tolerated and produced good short-term outcomes. SC-HART therefore appeared to have a good feasibility for use in further clinical trials. (author)

  5. Neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer.

    Doi, Hiroshi; Beppu, Naohito; Odawara, Soichi; Tanooka, Masao; Takada, Yasuhiro; Niwa, Yasue; Fujiwara, Masayuki; Kimura, Fumihiko; Yanagi, Hidenori; Yamanaka, Naoki; Kamikonya, Norihiko; Hirota, Shozo

    2013-11-01

    The purpose of this study was to examine the safety and feasibility of a novel protocol of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer. A total of 56 patients with lower rectal cancer of cT3N1M0 (Stage III b) was treated with SC-HART followed by radical surgery, and were analyzed in the present study. SC-HART was performed with a dose of 2.5 Gy twice daily, with an interval of at least 6 hours between fractions, up to a total dose of 25 Gy (25 Gy in 10 fractions for 5 days) combined with S-1 for 10 days. Radical surgery was performed within three weeks following the end of the SC-HART. The median age was 64.6 (range, 39-85) years. The median follow-up term was 16.3 (range, 2-53) months. Of the 56 patients, 53 (94.4%) had no apparent adverse events before surgery; 55 (98.2%) completed the full course of neoadjuvant therapy, while one patient stopped chemotherapy because of Grade 3 gastrointestinal toxicity (CTCAE v.3). The sphincter preservation rate was 94.6%. Downstaging was observed in 45 patients (80.4%). Adjuvant chemotherapy was administered to 43 patients (76.8%). The local control rate, disease-free survival rate and disease-specific survival rate were 100%, 91.1% and 100%, respectively. To conclude, SC-HART combined with S-1 for locally advanced rectal cancer was well tolerated and produced good short-term outcomes. SC-HART therefore appeared to have a good feasibility for use in further clinical trials. PMID:23658415

  6. Procedure to measure the neutrons spectrum around a lineal accelerator for radiotherapy

    An experimental procedure was developed, by means of Bonner spheres, to measure the neutrons spectrum around Linacs of medical use that only requires of a single shot of the accelerator; to this procedure we denominate Planetary or Isocentric method. One of the problems associated to the neutrons spectrum measurement in a radiotherapy room with lineal accelerator is because inside the room a mixed, intense and pulsed radiation field takes place affecting the detection systems based on active detector; this situation is solved using a passive detector. In the case of the Bonner spheres spectrometer the active detector has been substituted by activation detectors, trace detectors or thermoluminescent dosimeters. This spectrometer uses several spheres that are situated one at a time in the measurement point, this way to have the complete measurements group the accelerator should be operated, under the same conditions, so many times like spheres have the spectrometer, this activity can consume a long time and in occasions due to the work load of Linac to complicate the measurement process too. The procedure developed in this work consisted on to situate all the spectrometer spheres at the same time and to make the reading by means of a single shot, to be able to apply this procedure, is necessary that before the measurements two characteristics are evaluated: the cross-talking of the spheres and the symmetry conditions of the neutron field. This method has been applied to determine the photo-neutrons spectrum produced by a lineal accelerator of medical use Varian ix of 15 MV to 100 cm of the isocenter located to 5 cm of depth of a solid water mannequin of 30 x 30 x 15 cm. The spectrum was used to determine the total flow and the environmental dose equivalent. (Author)

  7. Quality of life assessment in advanced non-small-cell lung cancer patients undergoing an accelerated radiotherapy regimen: report of ECOG study 4593

    Purpose: To prospectively evaluate the quality of life (QOL) before, at completion, and after therapy for patients receiving an accelerated fractionation schedule of radiotherapy for advanced, unresectable non-small-cell lung cancer in a Phase II multi-institutional trial. Methods and Materials: The Functional Assessment of Cancer Therapy-Lung (FACT-L) patient questionnaire was used to score the QOL in patients enrolled in the Eastern Cooperative Oncology Group Phase II trial (ECOG 4593) of hyperfractionated accelerated radiotherapy in non-small-cell lung cancer. Radiotherapy (total dose 57.6 Gy in 36 fractions) was delivered during 15 days, with three radiation fractions given each treatment day. The protocol was activated in 1993, and 30 patients had accrued by November 1995. The FACT-L questionnaire was administered at study entry (baseline), on the last day of radiotherapy (assessment 2), and 4 weeks after therapy (assessment 3). The FACT-L includes scores for physical, functional, emotional, and social well-being (33 items), and a subscale of lung cancer symptoms (10 additional items). The summation of the physical, functional, and lung cancer symptom subscales (21 items) constitutes the Trial Outcome Index (TOI), considered the most clinically relevant outcome measure in lung cancer treatment trials. Results: The FACT-L completion rates at the designated study time points were as follows: baseline, 30 of 30 (100%); assessment 2, 29 (97%) of 30; and assessment 3, 24 (80%) of 30. At treatment completion, statistically significant declines in QOL scores were noted, compared with baseline for physical and functional well-being. Emotional well-being scores improved at both assessment 2 and assessment 3. The physical and functional scores returned approximately to baseline values at assessment 3. The change in TOI score was evaluated as a function of the clinical response to treatment, toxicity grade, and survival; no clear association was noted. A trend for the

  8. Intracranial tumours after external fractionated radiotherapy for pituitary adenomas in northern Sweden

    Norberg, Lars; Johansson, Robert; Rasmuson, Torgny (Dept. of Radiation Sciences, Oncology, Umeaa Univ., Umeaa (Sweden)), E-mail: Torgny.Rasmuson@onkologi.umu.se

    2010-11-15

    We analysed the incidence of second primary intracranial tumours in patients with pituitary adenomas treated with radiotherapy compared to the risk of patients not exposed to irradiation and to the general population. Materials and methods. This retrospective cohort study includes 298 patients with pituitary adenomas that received radiotherapy to the pituitary from 1960 to 2007. The patients were recruited from the Cancer Registry of northern Sweden and the local radiotherapy-registry of the Univ. Hospital in Umeaa. Only patients with =12 months follow-up after diagnosis of pituitary adenoma were included. A cohort of 131 patients with pituitary adenomas not treated with radiotherapy was used as reference. Standard incidence ratios (SIR) between observed and expected number of second primary intracranial tumours were calculated. Results. The median observation time after diagnosis of pituitary adenoma in 298 patients treated with radiotherapy was 14 years, and the total number of person-years at risk was 4 784. Six (2.0%) of the patients developed second primary intracranial tumours between 7 and 31 years after radiotherapy. Two patients had gliomas and four had meningiomas. The expected number of intracranial tumours was 1.15 giving a SIR of 5.20 (95% CI 1.90-11.31). No significant correlations were found between radiation technique or administered dose and the risk of developing a second primary intracranial tumour. The cumulative risk for second intracranial tumours at 10 and 20 years was 1.3%. Patients not treated with radiotherapy were followed 1 601 years and no second primary intracranial tumour occurred. Discussion. The results indicate an increased risk of second primary intracranial tumours in patients treated with radiotherapy for pituitary adenomas, compared to patients not exposed to irradiation and to the general population. Meningiomas were more frequent than gliomas and the median time interval between radiotherapy and second intracranial tumour was

  9. Radiotherapy

    The need for radiotherapy research is exemplified by the 100,000 cancer patients who will fail treatment locally and/or regionally annually for the next several years but who would benefit from better local treatment modalities. Theoretically, all of the areas of investigation discussed in this projection paper have the potential to significantly improve local-regional treatment of cancer by radiotherapy alone or in combination with other modalities. In many of the areas of investigation discussed in this paper encouraging results have been obtained in cellular and animal tumor studies and in limited studies in humans as well. In the not too distant future the number of patients who would benefit from better local control may increase by tens of thousands if developments in chemotherapy and/or immunotherapy provide a means to eradicate disseminated microscopic foci of cancer. Thus the efforts to improve local-regional control take on even greater significance

  10. A low-dose hypersensitive keratinocyte loss in response to fractionated radiotherapy is associated with growth arrest and apoptosis

    Background and purpose: The existence of a hypersensitive radiation response to doses below 0.5 Gy is well established for many normal and tumour cell lines. There is also evidence for hypersensitive tissue responses in acute skin damage and kidney function in mice. Recently, we have identified that a hypersensitive γH2AX response exists in human epidermis. The aim of this study was to investigate the dose-response of basal clonogenic keratinocytes in normal skin to fractionated radiotherapy with low dose fractions. Materials: Skin punch biopsies were taken before and during radiotherapy from prostate cancer patients undergoing radiotherapy with a curative intent. Areas of epidermis receiving daily fractions of approximately 0.1, 0.2, 0.45 and 1.1 Gy were biopsied on the same occasion to determine dose-response for each individual patient. In total, 89 cases were assessed either at 1, 2.5, 3, 4, 5 or 6.5 weeks in the treatment course. Biopsy sampling of another 25 patients was performed from areas receiving 0.45 and 1.1 Gy per fraction at regular intervals throughout the 7-week treatment period. The number of basal keratinocytes per mm of the interfollicular epidermis was determined. The DNA damage response of the basal keratinocytes was investigated by immunohistochemical staining for molecular markers of growth arrest, mitosis and cell death, using p21, phospho-H3 and γH2AX, respectively. The number of stained keratinocytes in the basal layer was counted manually. The p21 staining was also quantified by digital image analysis. Results: The individual dose-response relationships revealed a low-dose hypersensitivity for reduction of basal keratinocytes throughout 7 weeks of radiotherapy (p < 0.01). Growth arrest and cell proliferation assessed at 1 week and 6.5 weeks showed, in both cases, hypersensitive increase of p21 (p < 0.01) and hypersensitive depression of mitosis (p < 0.01). Manual counting and digital image analysis of p21 showed good agreement. Cell

  11. Cyberknife fractionated radiotherapy for adrenal metastases: Preliminary report from a multispecialty Indian cancer care center

    Trinanjan Basu; Tejinder Kataria; Ashu Abhishek; Deepak Gupta; Shikha Goyal; Shyam S. Bisht; Karthick K Payaliappan; Vikraman Subhramani

    2015-01-01

    Purpose: Metastasis to adrenal gland from lung, breast, and kidney malignancies are quite common. Historically radiotherapy was intended for pain palliation. Recent studies with stereotactic body radiotherapy (SBRT) including Cyberknife robotic radiosurgery aiming at disease control brings about encouraging results. Here we represent the early clinical experience with Cyberknife stereotactic system from an Indian cancer care center. The main purpose of this retrospective review is to serve as...

  12. 20 Gy in five fractions versus 8 Gy in one fraction in palliative radiotherapy of bone metastases. A multicenter randomized study

    Bone is the most common site of cancer dissemination and 70% of patients with bone lesions present with pain requiring therapy. Radiotherapy plays a major role in the treatment of painful bone metastases, but optimal dose and fractionation regime remain debatable. To address this issue a randomized trial comparing a single dose of 8 Gy vs. 20 Gy in 5 fractions was performed and enrolled 115 patients with 146 metastatic lesions. Pain relief was assessed longitudinally based on a pain questionnaire, in which patients were supposed to record their pain intensity using a 4-point scale (none, mild, moderate, severe), as well as doses and types of analgesic drugs taken. Questionnaires were collected prior to treatment, 2, 4 and 8 weeks after treatment completion and every 4 weeks thereafter. Complete pain relief was achieved in 23 patients (36%) treated with one fraction of 8 Gy and in 24 patients (39%) who received 20 Gy in 5 fractions (p=0.96). Remarkable pain relief after one fraction and 5 fractions was achieved in 21 patients (33%) and 18 patients (29%), respectively (p=0.89) and moderate pain relief in 9 patients (14%) and 10 patients (16%), respectively (p=0.94). There was also no difference between the two treatment regimes according to duration of pain relief (medians of 8 and 10 months, respectively). Single fraction of 8 Gy is equally effective to a fractionated schedule in the treatment of painful bone metastases, and should be recommended as standard care in the majority of patients. (author)

  13. Randomised phase I/II study to evaluate carbon ion radiotherapy versus fractionated stereotactic radiotherapy in patients with recurrent or progressive gliomas: The CINDERELLA trial

    Haselmann Renate

    2010-10-01

    Full Text Available Abstract Background Treatment of patients with recurrent glioma includes neurosurgical resection, chemotherapy, or radiation therapy. In most cases, a full course of radiotherapy has been applied after primary diagnosis, therefore application of re-irradiation has to be applied cauteously. With modern precision photon techniques such as fractionated stereotactic radiotherapy (FSRT, a second course of radiotherapy is safe and effective and leads to survival times of 22, 16 and 8 months for recurrent WHO grade II, III and IV gliomas. Carbon ions offer physical and biological characteristics. Due to their inverted dose profile and the high local dose deposition within the Bragg peak precise dose application and sparing of normal tissue is possible. Moreover, in comparison to photons, carbon ions offer an increased relative biological effectiveness (RBE, which can be calculated between 2 and 5 depending on the GBM cell line as well as the endpoint analyzed. Protons, however, offer an RBE which is comparable to photons. First Japanese Data on the evaluation of carbon ion radiation therapy for the treatment of primary high-grade gliomas showed promising results in a small and heterogeneous patient collective. Methods Design In the current Phase I/II-CINDERELLA-trial re-irradiation using carbon ions will be compared to FSRT applied to the area of contrast enhancement representing high-grade tumor areas in patients with recurrent gliomas. Within the Phase I Part of the trial, the Recommended Dose (RD of carbon ion radiotherapy will be determined in a dose escalation scheme. In the subsequent randomized Phase II part, the RD will be evaluated in the experimental arm, compared to the standard arm, FSRT with a total dose of 36 Gy in single doses of 2 Gy. Primary endpoint of the Phase I part is toxicity. Primary endpoint of the randomized part II is survival after re-irradiation at 12 months, secondary endpoint is progression-free survival. Discussion The

  14. Randomized trial of palliative two-fraction versus more intensive 13-fraction radiotherapy for patients with inoperable non-small cell lung cancer and good performance status

    Macbeth, F.R. [Glasgow Western Infirmary (United Kingdom); Bolger, J.J. [Weston Park Hospital, Sheffield (United Kingdom); Hopwood, P. [Christie Hospital and Holt Radium Inst., Manchester (United Kingdom); Bleehen, N.M. [Addenbrooke`s Hospital, Cambridge (United Kingdom); Cartmell, J.; Girling, D.J.; Machin, D.; Stephens, R.J.; Bailey, A.J. [Medical Research Council, Cambridge (United Kingdom)

    1996-11-01

    In patients with non-metastatic but inoperable non-small lung cancer that is locally too extensive for radical radiotherapy (RT), but who have good performance status, it is important to determine whether thoracic RT should be the minimum that is required to palliate thoracic symptoms or whether treatment should be more intensive, with the aim of prolonging survival. A total of 509 such patients from 11 centres in the UK between November 1989 and October 1992 were admitted to a trial comparing palliative versus more intensive RT with respect to survival and quality of life. They were allocated at random to receive thoracic RT with either 17 Gy in two fractions (F2) 1 week apart (255 patients) or 39 Gy in 13 fractions (F13) 5 days per week (254 patients). (author).

  15. Simultaneous optimization of dose distributions and fractionation schemes in particle radiotherapy

    Unkelbach, J.; Zeng, C.; Engelsman, M.

    2013-01-01

    Purpose: The paper considers the fractionation problem in intensity modulated proton therapy (IMPT). Conventionally, IMPT fields are optimized independently of the fractionation scheme. In this work, we discuss the simultaneous optimization of fractionation scheme and pencil beam intensities. Meth

  16. Adjuvant or radical fractionated stereotactic radiotherapy for patients with pituitary functional and nonfunctional macroadenoma

    Weber Damien C

    2011-12-01

    Full Text Available Abstract Purpose To evaluate the efficacy and toxicity of stereotactic fractionated radiotherapy (SFRT for patients with pituitary macroadenoma (PMA. Methods and Materials Between March 2000 and March 2009, 27 patients (male to female ratio, 1.25 with PMA underwent SFRT (median dose, 50.4 Gy. Mean age of the patients was 56.5 years (range, 20.3 - 77.4. In all but one patient, SFRT was administered for salvage treatment after surgical resection (transphenoidal resection in 23, transphenoidal resection followed by craniotomy in 2 and multiple transphenoidal resections in another patient. In 10 (37% patients, the PMAs were functional (3 ACTH-secreting, 3 prolactinomas, 2 growth hormone-secreting and 2 multiple hormone-secretion. Three (11.1% and 9 (33.3% patients had PMA abutting and compressing the optic chiasm, respectively. Mean tumor volume was 2.9 ± 4.6 cm3. Eighteen (66.7% patients had hypopituitarism prior to SFRT. The mean follow-up period after SFRT was 72.4 ± 37.2 months. Results Tumor size decreased for 6 (22.2% patients and remained unchanged for 19 (70.4% other patients. Two (7.4% patients had tumor growth inside the prescribed treatment volume. The estimated 5-year tumor growth control was 95.5% after SFRT. Biochemical remission occurred in 3 (30% patients with functional PMA. Two patients with normal anterior pituitary function before SFRT developed new deficits 25 and 65 months after treatment. The 5-year survival without new anterior pituitary deficit was thus 95.8%. Five patients with visual field defect had improved visual function and 1 patient with no visual defect prior to SFRT, but an optic chiasm abutting tumor, had a decline in visual function. The estimated 5-year vision and pituitary function preservation rates were 93.2% and 95.8%, respectively. Conclusions SFRT is a safe and effective treatment for patients with PMA, although longer follow-up is needed to evaluate long-term outcomes. In this study, approximately 1

  17. Radiobiological Characterization of Two Photon-Beam Energies 6 and 15 MV used in Radiotherapy From Linear Accelerator

    The main objective of this study is to perform radiobiological characterization of two different photon beam energies, 6 MV and 15 MV, from linear accelerator used in radiotherapy, with special regard to late effects of radiation. Two end-points, namely cell survival and micronucleus induction were used for the characterization. Chinese hamster V 79 lung fibroblast cell line to prepare cell culture and to perform the innervate experiments. chromosomes number was counted and found to be 22 chromosomes per cell, this result is in complete agreement with expected 11 pairs of chromosomes representing the genome of this species. Cells were kept in confluent growth for two days and then exposed to two photon beam energies, 6 and 15 MV respectively. Different dose rates were used for the two beam energies, 0.25, 0.5, 1.0, 2.0, 4.0, 7.0 Gy. Cells were counted immediately after irradiation and re seeded, the seeded number of cells was calculated to the dose rate used. Another set of unirradiated cells treated the same as the experimental set was used as a control group. The plating efficiency (PE) was calculated for the control group, then cells were incubated at 37oC for 6 days to construct the survival curve, five samples were counted per dose and the mean was calculated. The two survival curves are similar for photon beam energies (6 and 15 MV) and the surviving fraction was decreased with dose rate. The two curves showed similar values of α and β parameters, this result is expected for the same radiation type (X-ray). For the micronuclei assay three samples for each dose were seeded and incubated at 37oC for 24 hours then Cytochalasin-B was added to block cells in cytokinesis phase of the mitosis. The micronuclei number was counted and plotted with dose. A significant positive correlation was found between dose and micronuclei frequency (P=0.00), moreover, the micronuclei frequency is relatively higher with 15 MV compared with 6 MV energy. This indicates the presence

  18. Clinical role of18F-FDG PET/CT-based simultaneous modulated accelerated radiotherapy treatment plan-ning for locally advanced nasopharyngeal carcinoma

    Jianshe Wang; Tianyou Tang Co-first author; Jing Xu; Andrew Z Wang; Liang Li; Junnian Zheng; Longzhen Zhang

    2015-01-01

    Objective The aim of this study was to compare the long-term local control, overal survival, and late toxicities of positron emission tomography/computed tomography (PET/CT)-guided dose escalation radio-therapy versus conventional radiotherapy in the concurrent chemoradiotherapy treatment of local y ad-vanced nasopharyngeal carcinoma (NPC). Methods A total of 48 patients with stage III–IVa NPC were recruited and randomly administered PET/CT-guided dose escalation chemoradiotherapy (group A) or conventional chemoradiotherapy (group B). The dose-escalation radiotherapy was performed using the simultaneous modulated accelerated radiotherapy technique at prescribed doses of 77 gray (Gy) in 32 fractions (f) to the gross target volume (GTV): planning target volume (PTV) 1 received 64 Gy/32 f, while PTV2 received 54.4 Gy/32 f. Patients in group B received uniform-dose intensity-modulated radiotherapy, PTV1 received 70 Gy/35 f and PTV2 received 58 Gy/29 f. Concurrent chemotherapy consisted of cisplatin [20 mg/m2 intravenous (IV) on days 1–4] and docetaxel (75 mg/m2 IV on days 1 and 8) administered during treatment weeks 1 and 4. Al patients received 2–4 cycles of adjuvant chemotherapy of the same dose and drug regimen. Results The use of fluorine-18-fluorodeoxyglucose (18F-FDG) PET/CT significantly reduced the treat-ment volume delineation of the GTV in 83.3% (20/24) of patients. The 5-year local recurrence-free survival rates of the two groups were 100% and 79.2%, respectively (P = 0.019). The 5-year disease free survival (DFS) rates were 95.8% and 75.0%, respectively (P = 0.018). The 5-year local progression-free survival and DFS rates were significantly dif erent. The 5-year overal survival (OS) rates were 95.8% and 79.2%, re-spectively. Dif erences in OS improvement were insignificant (P = 0.079). Late toxicities were similar in the two groups. The most common late toxicities of the two arms were grade 1–2 skin dystrophy, xerostomia, subcutaneous fibrosis, and

  19. Patient position reproducibility in fractionated stereotactically guided conformal radiotherapy using the BrainLab trademark mask system

    Purpose: Dedicated mask systems nowadays allow the use of stereotactic radiotherapy in fractionated regimes, therefore combining the advantages of high precision radiotherapy with the biological benefit of fractionation. Therefore the knowledge of institution specific isocenter accuracy is essential for decision-making about margins to be allowed to form the planning target volume. Patients and Method: Measurements of isocenter deviations during fractionated treatments were performed in 33 patients using the simulator Simulix-xy (Oldelft) in connection with the BrainLab trademark angiographic localizer-box as well as port-films. In both cases repeated images were overlaid by use of anatomical landmarks with a methodical accuracy in the order of 0.5 mm. Results: Both methods yield random isocenter deviations of less then 2 mm (standard deviation) in all three directions and no significant systematic deviations. These values are in the order of the accuracy of the method, obtained by comparison of two independent investigators, as well as they are comparable with the literature. Conclusions: The accuracy of less than 2 mm indicates safety margins of 3-4 mm as sufficient for clinical routine to cover the target in 95.5% of all set-ups (2 SD). (orig.)

  20. Tumor Localization Using Cone-Beam CT Reduces Setup Margins in Conventionally Fractionated Radiotherapy for Lung Tumors

    Purpose: To determine whether setup margins can be reduced using cone-beam computed tomography (CBCT) to localize tumor in conventionally fractionated radiotherapy for lung tumors. Methods and Materials: A total of 22 lung cancer patients were treated with curative intent with conventionally fractionated radiotherapy using daily image guidance with CBCT. Of these, 13 lung cancer patients had sufficient CBCT scans for analysis (389 CBCT scans). The patients underwent treatment simulation in the BodyFix immobilization system using four-dimensional CT to account for respiratory motion. Daily alignment was first done according to skin tattoos, followed by CBCT. All 389 CBCT scans were retrospectively registered to the planning CT scans using automated soft-tissue and bony registration; the resulting couch shifts in three dimensions were recorded. Results: The daily alignment to skin tattoos with no image guidance resulted in systematic (Σ) and random (σ) errors of 3.2-5.6 mm and 2.0-3.5 mm, respectively. The margin required to account for the setup error introduced by aligning to skin tattoos with no image guidance was approximately 1-1.6 cm. The difference in the couch shifts obtained from the bone and soft-tissue registration resulted in systematic (Σ) and random (σ) errors of 1.5-4.1 mm and 1.8-5.3 mm, respectively. The margin required to account for the setup error introduced using bony anatomy as a surrogate for the target, instead of localizing the target itself, was 0.5-1.4 cm. Conclusion: Using daily CBCT soft-tissue registration to localize the tumor in conventionally fractionated radiotherapy reduced the required setup margin by up to approximately 1.5 cm compared with both no image guidance and image guidance using bony anatomy as a surrogate for the target.

  1. Pain relief and quality of life following radiotherapy for bone metastases: a randomised trial of two fractionation schedules

    Background: The optimum dose and fractionation schedule for the palliative irradiation of painful bone metastases is controversial. Purpose: To compare the efficacy, side-effects and effect on quality of life of two commonly used radiotherapy schedules in the management of painful bone metastases. Materials and methods: In a prospective trial, 280 patients were randomised to receive either a single 10 Gy treatment or a course of 22.5 Gy in five daily fractions for the relief of localised metastatic bone pain. Results: Response rates have been calculated from 240 assessable treated sites of pain. The overall response rates were 83.7% (single treatment) and 89.2% (five fractions). The complete response rates were 38.8% (single treatment) and 42.3% (five fractions). The median duration of pain control was 13.5 weeks (single treatment) and 14.0 weeks (five fractions). None of these differences was statistically significant. There were no differences between the groups in the effect of treatment on a variety of quality of life parameters. Conclusions: It is concluded that a single 10 Gy treatment is as effective as a course of 22.5 Gy in five fractions in the management of painful bone metastases

  2. 18F-EF5 PET Is Predictive of Response to Fractionated Radiotherapy in Preclinical Tumor Models

    Rehan Ali; Sandeep Apte; Marta Vilalta; Murugesan Subbarayan; Zheng Miao; Chin, Frederick T.; Graves, Edward E.

    2015-01-01

    We evaluated the relationship between pre-treatment positron emission tomography (PET) using the hypoxic tracer 18F-[2-(2-nitro-1-H-imidazol-1-yl)-N-(2,2,3,3,3- pentafluoropropyl) acetamide] (18F-EF5) and the response of preclinical tumor models to a range of fractionated radiotherapies. Subcutaneous HT29, A549 and RKO tumors grown in nude mice were imaged using 18F-EF5 positron emission tomography (PET) in order to characterize the extent and heterogeneity of hypoxia in these systems. Based ...

  3. Determining inter-fractional motion of the uterus using 3D ultrasound imaging during radiotherapy for cervical cancer

    Baker, Mariwan; Jensen, Jørgen Arendt; Behrens, Claus F.

    2014-01-01

    Uterine positional changes can reduce the accuracy of radiotherapy for cervical cancer patients. The purpose of this study was to; 1) Quantify the inter-fractional uterine displacement using a novel 3D ultrasound (US) imaging system, and 2) Compare the result with the bone match shift determined...... by Cone-Beam CT (CBCT) imaging.Five cervical cancer patients were enrolled in the study. Three of them underwent weekly CBCT imaging prior to treatment and bone match shift was applied. After treatment delivery they underwent a weekly US scan. The transabdominal scans were conducted using a Clarity US...

  4. 3H-DOPA: Distribution in the subcellular fractions of melanomas and its perspective use in radiotherapy

    The incorporation of 3H-DOPA (740 MBq per mouse) into the subcellular fractions of Harding-Passey's melanoma was studied simultaenously with tyrosinase activity determination up to 2 days. The kinetics of 3H-DOPA was checked by means of electron histoautoradiography 30 min, 1, 3 and 24 hours, respectively, after injection. Maximum incorporation of 3H-DOPA was found in mitochondria and melanosomes as well as high tyrosinase activity. DOPA is supposed to be used for internal radiotherapy of melanomas. (author)

  5. SU-F-BRF-12: Investigating Dosimetric Effects of Inter-Fraction Deformation in Lung Cancer Stereotactic Body Radiotherapy (SBRT)

    Purpose: We studied dosimetric effects of inter-fraction deformation in lung stereotactic body radiotherapy (SBRT), in order to investigate the necessity of adaptive re-planning for lung SBRT treatments. Methods: Six lung cancer patients with different treatment fractions were retrospectively investigated. All the patients were immobilized and localized with a stereotactic body frame and were treated under cone-beam CT (CBCT) image guidance at each fraction. We calculated the actual delivered dose of the treatment plan using the up-to-date patient geometry of each fraction, and compared the dose with the intended plan dose to investigate the dosimetric effects of the inter-fraction deformation. Deformable registration was carried out between the treatment planning CT and the CBCT of each fraction to obtain deformed planning CT for more accurate dose calculations of the delivered dose. The extent of the inter-fraction deformation was also evaluated by calculating the dice similarity coefficient between the delineated structures on the planning CT and those on the deformed planning CT. Results: The average dice coefficients for PTV, spinal cord, esophagus were 0.87, 0.83 and 0.69, respectively. The volume of PTV covered by prescription dose was decreased by 23.78% on average for all fractions and all patients. For spinal cord and esophagus, the volumes covered by the constraint dose were increased by 4.57% and 3.83%. The maximum dose was also increased by 4.11% for spinal cord and 4.29% for esophagus. Conclusion: Due to inter-fraction deformation, large deterioration was found in both PTV coverage and OAR sparing, which demonstrated the needs for adaptive re-planning of lung SBRT cases to improve target coverage while reducing radiation dose to nearby normal tissues

  6. Predicting Rectal and Bladder Overdose During the Course of Prostate Radiotherapy Using Dose-Volume Data From Initial Treatment Fractions

    Purpose: To evaluate whether information from the initial fractions can determine which patients are likely to consistently exceed their planning dose–volume constraints during the course of radiotherapy for prostate cancer. Methods and Materials: Ten patients with high-risk prostate cancer were treated with helical tomotherapy to a dose of 60 Gy in 20 fractions. The prostate, rectum, and bladder were recontoured on their daily megavoltage computed tomography scans and the dose was recalculated. The bladder and rectal volumes (in mL) receiving ≥100% and ≥70% of the prescribed dose in each fraction and in the original plans were recorded. A fraction for which the difference between planned and delivered was more than 2 mL was considered a volume failure. Similarly if the difference in the planned and delivered maximum dose (Dmax) was ≥1% for the rectum and bladder, the fraction was considered a dose failure. Each patient’s first 3 to 5 fractions were analyzed to determine if they correctly identified those patients who would consistently fail (i.e., ≥20% of fractions) during the course of their radiotherapy. Results: Six parameters were studied; the rectal volume (RV) and bladder volumes (BV) (in mL) received ≥100% and ≥70% of the prescribed dose and maximum dose to 2 mL of the rectum and bladder. This was given by RV100, RV70, BV100, BV70, RDmax, and BDmax, respectively. When more than 1 of the first 3 fractions exceed the planning constraint as defined, it accurately predicts consistent failures through the course of the treatment. This method is able to correctly identify the consistent failures about 80% (RV70, BV100, and RV100), 90% (BV70), and 100% (RDmax and BDmax) of the times. Conclusions: This study demonstrates the feasibility of a method accurately identifying patients who are likely to consistently exceed the planning constraints during the course of their treatment, using information from the first 3 to 5 fractions.

  7. Retrospective study on therapy options of brain metastases surgery versus stereotactic radiotherapy with the linear accelerator

    Fortunati, M K S

    2001-01-01

    Background: in the therapy of brain metastases there has been a great progress in the last years. It was shown, that more aggressive therapies can not only extend the survival of the patients, but also improve quality of life. The major question of this study was, whether surgery or stereotactic radiotherapy with the linear accelerator show better results in behalf of the survival. Beside this major question many parameters regarding the patient or his primary cancer were examined. Methods: from the 1st of January 1995 until the 30th of June 2000 233 patients with one or more brain metastases have been treated in the Wagner Jauregg Landesnervenkrankenhaus Oberoesterreich (WJ LNKH OeO). The LINAC has been established on the 1st of July 1997. The patients have been distributed in three groups: 1. LINAC-group: 81 patients have been treated from the 1st of July 1997 until the 30th of June 2000 with the LINAC. 2. Surgery-group: 81 patients have been operated from the 1st of July 1997 until the 30th June 2000. 3 Co...

  8. Determining optimization of the initial parameters in Monte Carlo simulation for linear accelerator radiotherapy

    Chang, Kwo-Ping; Wang, Zhi-Wei; Shiau, An-Cheng

    2014-02-01

    Monte Carlo (MC) method is a well known calculation algorithm which can accurately assess the dose distribution for radiotherapy. The present study investigated all the possible regions of the depth-dose or lateral profiles which may affect the fitting of the initial parameters (mean energy and the radial intensity (full width at half maximum, FWHM) of the incident electron). EGSnrc-based BEAMnrc codes were used to generate the phase space files (SSD=100 cm, FS=40×40 cm2) for the linac (linear accelerator, Varian 21EX, 6 MV photon mode) and EGSnrc-based DOSXYZnrc code was used to calculate the dose in the region of interest. Interpolation of depth dose curves of pre-set energies was proposed as a preliminary step for optimal energy fit. A good approach for determination of the optimal mean energy is the difference comparison of the PDD curves excluding buildup region, and using D(10) as a normalization method. For FWHM fitting, due to electron disequilibrium and the larger statistical uncertainty, using horn or/and penumbra regions will give inconsistent outcomes at various depths. Difference comparisons should be performed in the flat regions of the off-axis dose profiles at various depths to optimize the FWHM parameter.

  9. Tcp and NTCP radiobiological models: conventional and hypo fractionated treatments in radiotherapy

    Astudillo V, A.; Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Resendiz G, G.; Posadas V, A. [Hospital Angeles Lomas, Av. Vialidad de la Barranca s/n, Col. Valle de las Palmas, 52763 Huixquilucan de Degallado, Estado de Mexico (Mexico); Mitsoura, E. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan, Esq. Jesus Carranza s/n, Col. Moderna de la Cruz, 50180 Toluca, Estado de Mexico (Mexico); Rodriguez L, A.; Flores C, J. M., E-mail: armando.astudillo@inin.gob.mx [Hospital Medica Sur, Puente de Piedra 150, Col. Toriello Guerra, 14050 Tlalpan, Mexico D. F. (Mexico)

    2015-10-15

    The hypo and conventional fractionated schedules performance were compared in terms of the tumor control and the normal tissue complications. From the records of ten patients, treated for adenocarcinoma and without mastectomy, the dose-volume histogram was used. Using radiobiological models the probabilities for tumor control and normal tissue complications were calculated. For both schedules the tumor control was approximately the same. However, the damage in the normal tissue was larger in conventional fractionated schedule. This is important because patients assistance time to their fractions (15 fractions/25 fractions) can be optimized. Thus, the hypo fractionated schedule has suitable characteristics to be implemented. (Author)

  10. Tcp and NTCP radiobiological models: conventional and hypo fractionated treatments in radiotherapy

    The hypo and conventional fractionated schedules performance were compared in terms of the tumor control and the normal tissue complications. From the records of ten patients, treated for adenocarcinoma and without mastectomy, the dose-volume histogram was used. Using radiobiological models the probabilities for tumor control and normal tissue complications were calculated. For both schedules the tumor control was approximately the same. However, the damage in the normal tissue was larger in conventional fractionated schedule. This is important because patients assistance time to their fractions (15 fractions/25 fractions) can be optimized. Thus, the hypo fractionated schedule has suitable characteristics to be implemented. (Author)

  11. Locoregionally advanced carcinoma of the oropharynx: conventional radiotherapy vs. accelerated hyperfractionated radiotherapy vs. concomitant radiotherapy and chemotherapy - a multicenter randomized trial

    Purpose: To compare conventional fractionation radiation therapy (RT), Arm A, vs. split-course accelerated hyperfractionated RT (S-AHF), Arm B, vs. conventional fractionation RT plus concomitant chemotherapy (CT), Arm C, in terms of survival and toxicity for advanced, unresectable epidermoid tumors of oropharynx. Methods and Materials: Between January 1993 and June 1998, 192 previously untreated patients affected with Stage III and IV oropharyngeal carcinoma (excluding T1N1 and T2N1) were accrued in a multicenter, randomized Phase III trial (ORO 93-01). For Arms A and C, 66-70 Gy in 33-35 fractions, 5 days a week, were administered in 6.5-7 weeks to tumor and positive nodes. In Arm B, the dose delivered to tumor and involved nodes was 64-67.2 Gy, giving 2 fractions of 1.6 Gy every day with an interfraction interval of at least 4 h and preferably 6 h, 5 days a week. At 38.4 Gy, a 2-week split was planned; after the split, RT was resumed with the same modality. In Arm C, CT regimen consisted of carboplatin and 5-fluorouracil (CBDCA 75 mg/m2, Days 1-4; 5-FU 1,000 mg/m2 i.v. over 96 h, Days 1-4, recycling every 28 days (at 1st, 5th, and 9th week). Results: No statistically significant difference was detected in overall survival (p=0.129): 40% Arm A vs. 37% Arm B vs. 51% Arm C were alive at 24 months. Similarly, there was no statistically significant difference in terms of event-free survival (p=0.196): 20% for Arm A, 19% for Arm B, and 37% for Arm C were event free at 24 months. On the contrary, the 2-year disease-free survival was significantly different among the three arms (p = 0.022), with a superiority for Arm C. At 24 months, the proportion of patients without relapse was 42% for Arm C vs. 23% for Arm A and 20% for Arm B. Patients in Arm A less frequently developed G3+ acute mucositis than their counterparts in Arm B or C (14.7% vs. 40.3% vs. 44%). Regarding the CT-related acute toxicity, apart from 1 case of fatal nephrotoxicity, only hematologic G3+ (Grade 3 or

  12. Thyroid dysfunction as a late effect in childhood medulloblastoma: a comparison of hyperfractionated versus conventionally fractionated craniospinal radiotherapy

    Purpose: Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of childhood medulloblastoma. Due to the strong radiobiologic rationale, hyperfractionation can reduce the delayed effects of radiation injury. Methods and Materials: The authors compared the incidence of thyroid dysfunction after conventionally fractionated radiotherapy (Group A, n=20 patients) vs. hyperfractionated radiotherapy (Group B, n=12 patients) in a group of pediatric patients with posterior fossa primitive neuroectodermal tumor (PNET). Results: The mean age at the time of tumor diagnosis was 7.4 years in Group A and 8.4 years in Group B. Thyroid function was evaluated yearly, with ultrasonographic examination every 2 years. The patients were followed after diagnosis for a mean of 10.8 years for Group A and 6.0 years for Group B. Approximately 80% of the Group A (16/20) and 33.3% of the Group B (4/12) patients developed primary hypothyroidism within a similar period after irradiation (4.2 vs. 3.5 years, respectively). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (p<0.05). Ultrasonography showed reduced thyroid volume in 7 Group A patients and structural changes in 21 patients (17 Group A, 4 Group B cases); a thyroid benign nodule was detected in 2 Group A patients. Conclusions: The current study findings suggest that the use of hyperfractionated craniospinal radiotherapy in the treatment of childhood medulloblastoma is associated with a lower risk of these patients' developing late thyroid dysfunction

  13. Clinical efficacy of conventionally fractionated versus hypofractionated three-dimensional conformal radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis

    Objective: To observe the efficacy and adverse effects of conventionally fractionated (CF) versus hypofractionated (HF) three-dimensional conformal radiotherapy (3DCRT) for hepatocellular carcinoma (HCC) with portal vein tumor thrombosis. Methods: A retrospective analysis was performed on the clinical data of 65 patients with HCC suitable for 3DCRT from 2008 to 2012. These patients were randomly divided into HF group (n =32) and CF group (n =32). The HF group received 3DCRT at a total dose of 45-55 Gy (3-4 Gy/fraction, 3-5 fractions/week), while the CF group at a total dose of 40-56 Gy (2 Gy/fraction, 5 fractions/week). Results: The follow-up rate was 100%.For the HF group and CF group, the short-term response rates were 72% vs. 55% (P=0.034), the 1-year local control rates were 72% vs. 55% (P=0.034), the 1-year overall survival rates were 59% vs. 45% (P=0.042), and the numbers of individuals with grade 1-2 acute gastrointestinal reactions, deterioration of liver function, and radiation hepatitis were 14 vs. 11, 8 vs. 8, and 1 vs. 0, respectively (P=0.237). Conclusions: HF 3DCRT is superior to CF 3DCRT in the treatment of HCC. (authors)

  14. Fractionated stereotactic radiotherapy of benign skull-base tumors: a dosimetric comparison of volumetric modulated arc therapy with Rapidarc® versus non-coplanar dynamic arcs

    Martin, Fanny; Magnier, Florian; Berger, Lucie; Miroir, Jessica; Chautard, Emmanuel; Verrelle, Pierre; Lapeyre, Michel; Biau, Julian

    2016-01-01

    Background Benign tumors of the skull base are a challenge when delivering radiotherapy. An appropriate choice of radiation technique may significantly improve the patient’s outcomes. Our study aimed to compare the dosimetric results of fractionated stereotactic radiotherapy between non-coplanar dynamic arcs and coplanar volumetric modulated arctherapy (Rapidarc®). Methods Thirteen patients treated with Novalis TX® were analysed: six vestibular schwannomas, four pituitary adenomas and three m...

  15. Long term results after fractionated stereotactic radiotherapy (FSRT) in patients with craniopharyngioma: maximal tumor control with minimal side effects

    There are already numerous reports about high local control rates in patients with craniopharyngioma but there are only few studies with follow up times of more than 10 years. This study is an analysis of long term control, tumor response and side effects after fractionated stereotactic radiotherapy (FSRT) for patients with craniopharyngioma. 55 patients who were treated with FSRT for craniopharyngioma were analyzed. Median age was 37 years (range 6–70 years), among them eight children < 18 years. Radiotherapy (RT) was indicated for progressive disease after neurosurgical resection or postoperatively after repeated resection or partial resection. A median dose of 52.2 Gy (50 – 57.6 Gy) was applied with typical dose per fraction of 1.8 Gy five times per week. The regular follow up examinations comprised in addition to contrast enhanced MRI scans thorough physical examinations and clinical evaluation. During median follow up of 128 months (2 – 276 months) local control rate was 95.3% after 5 years, 92.1% after 10 years and 88.1% after 20 years. Overall survival after 10 years was 83.3% and after 20 years 67.8% whereby none of the deaths were directly attributed to craniopharyngioma. Overall treatment was tolerated well with almost no severe acute or chronic side effects. One patient developed complete anosmia, another one’s initially impaired vision deteriorated further. In 83.6% of the cases with radiological follow up a regression of irradiated tumor residues was monitored, in 7 cases complete response was achieved. 44 patients presented themselves initially with endocrinologic dysfunction none of them showed signs of further deterioration during follow up. No secondary malignancies were observed. Long term results for patients with craniopharyngioma after stereotactic radiotherapy are with respect to low treatment related side effects as well as to local control and overall survival excellent

  16. Randomized clinical trial with two palliative radiotherapy regimens in painful bone metastases: 30 Gy in 10 fractions compared with 8 Gy in single fraction

    Background and purpose: The aim was to demonstrate similar pain relief with two schedules of radiotherapy for painful bone metastases. Materials and methods: A total of 160 patients were assigned to receive a single 8-Gy fraction or 30 Gy in 10 fractions. Pain intensity was measured on an ordinal pain scale of 0-10. Partial response was defined as a pain reduction of two points or more and complete response as a pain score of zero at the treated area. Response follow-up was at 3, 12, 24 and 48 weeks. Results: The overall response was 75% in the 8-Gy arm and 86% in the 30-Gy arm. Complete response and partial response rates were 15% and 60% in the 8-Gy arm, 13% and 73% in the 30-Gy arm. Acute toxicity was of 18% in the 30-Gy arm and of 12% in the 8-Gy arm. These differences were not statistically significant. The re-treatment rate was 28% vs 2% in the 8-Gy and 30-Gy arms, respectively, these were statistically significant. Conclusions: A single-fraction regimen of 8 Gy was as safe and effective as a multifraction regimen of 30 Gy for painful bone metastases in terms of pain relief

  17. Three-dimensional conformal arc radiotherapy using a C-arm linear accelerator with a computed tomography on-rail system for prostate cancer: clinical outcomes

    We report the feasibility and treatment outcomes of image-guided three-dimensional conformal arc radiotherapy (3D-CART) using a C-arm linear accelerator with a computed tomography (CT) on-rail system for localized prostate cancer. Between 2006 and 2011, 282 consecutive patients with localized prostate cancer were treated with in-room CT-guided 3D-CART. Biochemical failure was defined as a rise of at least 2.0 ng/ml beyond the nadir prostate-specific antigen level. Toxicity was scored according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. A total of 261 patients were analyzed retrospectively (median follow-up: 61.6 months). The median prescribed 3D-CART dose was 82 Gy (2 Gy/fraction, dose range: 78–86 Gy), and 193 of the patients additionally received hormonal therapy. The 5-year overall survival rate was 93.9 %. Among low-, intermediate-, and high-risk patients, 5-year rates of freedom from biochemical failure were 100, 91.5 and 90.3 %, respectively. Rates of grade 2–3 late gastrointestinal and genitourinary toxicities were 2.3 and 11.4 %, respectively. No patient experienced late grade 4 or higher toxicity. In-room CT-guided 3D-CART was feasible and effective for localized prostate cancer. Treatment outcomes were comparable to those previously reported for intensity-modulated radiotherapy

  18. Retrospective study on therapy options of brain metastases: surgery versus stereotactic radiotherapy with the linear accelerator

    Background: in the therapy of brain metastases there has been a great progress in the last years. It was shown, that more aggressive therapies can not only extend the survival of the patients, but also improve quality of life. The major question of this study was, whether surgery or stereotactic radiotherapy with the linear accelerator show better results in behalf of the survival. Beside this major question many parameters regarding the patient or his primary cancer were examined. Methods: from the 1st of January 1995 until the 30th of June 2000 233 patients with one or more brain metastases have been treated in the Wagner Jauregg Landesnervenkrankenhaus Oberoesterreich (WJ LNKH OeO). The LINAC has been established on the 1st of July 1997. The patients have been distributed in three groups: 1. LINAC-group: 81 patients have been treated from the 1st of July 1997 until the 30th of June 2000 with the LINAC. 2. Surgery-group: 81 patients have been operated from the 1st of July 1997 until the 30th June 2000. 3 Control-group: 71 patients have been operated from the 1st of January 1995 until the 30th of June 1997, before the LINAC has been established on the 1st of July 1997. Results: There are shown the mean survival times. Therapy options (0,05): LINAC-group: 377 days. Surgery-group: 195 days. Control-group: 285 days. Primary cancer (0,05): unknown primary: 203 days. Cancer of the colon tract: 218 days. Breast cancer: 314 days. Melanoma: 162 days. Kidney: 466 days. Lung 261 days. Others: 439 days. Metastases in one/in both hemispheres (0,05): in one hemisphere 310 days, in both 184 days. All the other parameters (age, sex, Karnofsky-Index, period between diagnose of the primary and the brain metastases, primary cancer therapy, extra cerebral metastases, number of metastases, localization of metastases supra- or infratentoriell, dose/effect relationship in the LINAC-group, whole brain radiotherapy) showed interesting differences, but the results were not statistically

  19. Development and Dosimetric Characterization of a Tissue Substitute (Bolus) For Use in Linear Accelerator Electron Radiotherapy

    We propose the design of a new custom made material, to be used as a tissue substitute in external beam electron radiotherapy, based on cotton fabric and beeswax. Due to its inexpensive, easy preparation, constant thickness, flexibility, uniform density and physical properties similar to those of soft tissue, this bolus will insure personalized optimal dose build up and dose distribution in irregular treatment regions. Materials and Methods: We used commercial Campeche beeswax and 100% cotton fabric to prepare the bolus. Beeswax's physical characteristics were determined by thermal and density analysis. Its chemical properties are to be determined by electronic microscopy. We performed quality control tests and calibration of the Varian 2100C linear accelerator. The tissue equivalence of the material is established for a range of electron energies (6, 9, 12, 16, 20 MeV) using a water equivalent solid phantom (PTW; Freiburg, Germany) and a plane parallel ionization chamber (PTW) associated to a PTW electrometer. Results: Beeswax's absolute density was found to be 0.9181g/ml at 21 deg. C, with a melting point of 45 deg. C. For the bolus elaboration, the cotton fabric was soaked in liquid beeswax and thin sheets of approximately 1 mm were obtained. These presented high flexibility, physical stability (color, texture, thickness) and homogeneity. Determination of this dosimetric characteristics and equivalent thickness are still in process. Discussion and conclusions: Our preliminary results suggest that the tissue substitute is easily made, inexpensive to produce, molds well to the treatment area and its positioning is easy and reproducible over the course of the treatment. So we consider that it's a good alternative to the commercial bolus

  20. Preoperative Single Fraction Partial Breast Radiotherapy for Early-Stage Breast Cancer

    Palta, Manisha; Yoo, Sua; Adamson, Justus D.; Prosnitz, Leonard R. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Horton, Janet K., E-mail: janet.horton@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

    2012-01-01

    Purpose: Several recent series evaluating external beam accelerated partial breast irradiation (PBI) have reported adverse cosmetic outcomes, possibly related to large volumes of normal tissue receiving near-prescription doses. We hypothesized that delivery of external beam PBI in a single fraction to the preoperative tumor volume would be feasible and result in a decreased dose to the uninvolved breast compared with institutional postoperative PBI historical controls. Methods and Materials: A total of 17 patients with unifocal Stage T1 breast cancer were identified. Contrast-enhanced subtraction magnetic resonance images were loaded into an Eclipse treatment planning system and used to define the target volumes. A 'virtual plan' was created using four photon beams in a noncoplanar beam arrangement and optimized to deliver 15 Gy to the planning target volume. Results: The median breast volume was 1,713 cm{sup 3} (range: 1,014-2,140), and the median clinical target volume was 44 cm{sup 3} (range: 26-73). In all cases, 100% of the prescription dose covered 95% of the clinical target volume. The median conformity index was 0.86 (range: 0.70-1.12). The median percentage of the ipsilateral breast volume receiving 100% and 50% of the prescribed dose was 3.8% (range: 2.2-6.9) and 13.3% (range: 7.5-20.8) compared with 18% (range: 3-42) and 53% (range: 24-65) in the institutional historical controls treated with postoperative external beam PBI (p = .002). The median maximum skin dose was 9 Gy. The median dose to 1 and 10 cm{sup 3} of skin was 6.7 and 4.9 Gy. The doses to the heart and ipsilateral lung were negligible. Conclusion: Preoperative PBI resulted in a substantial reduction in ipsilateral breast tissue dose compared with postoperative PBI. The skin dose appeared reasonable, given the small volumes. A prospective Phase I trial evaluating this technique is ongoing.

  1. Dosimetric consequences of tumor volume changes after kilovoltage cone-beam computed tomography for non-operative lung cancer during adaptive intensity-modulated radiotherapy or fractionated stereotactic radiotherapy

    Jian Hu; Ximing Xu; Guangjin Yuan; Wei Ge; Liming Xu; Aihua Zhang; Junjian Deng

    2015-01-01

    Objective The aim of this study was to investigate tumor volume changes with kilovoltage cone-beam computed tomography (kV-CBCT) and their dosimetric consequences for non-operative lung cancer during intensity-modulated radiotherapy (IMRT) or fractionated stereotactic radiotherapy. Methods Eighteen patients with non-operative lung cancer who received IMRT consisting of 1.8-2.2 Gy/fraction and five fractions per week or stereotactic radiotherapy with 5-8 Gy/fraction and three fractions a week were studied. kV-CBCT was performed once per week during IMRT and at every fraction during stereotactic radiotherapy. The gross tumor volume (GTV) was contoured on the kV-CBCT images, and adaptive treatment plans were created using merged kV-CBCT and primary planning computed tomogra-phy image sets. Tumor volume changes and dosimetric parameters, including the minimum dose to 95%(D95) or 1% (D1) of the planning target volume (PTV), mean lung dose (MLD), and volume of lung tissue that received more than 5 (V5), 10 (V10), 20 (V20), and 30 (V30) Gy were retrospectively analyzed. Results The average maximum change in GTV observed during IMRT or fractionated stereotactic radio-therapy was -25.85% (range, -13.09% --56.76%). The D95 and D1 of PTV for the adaptive treatment plans in all patients were not significantly different from those for the initial or former adaptive treatment plans. In patients with tumor volume changes of >20% in the third or fourth week of treatment during IMRT, adap-tive treatment plans offered clinically meaningful decreases in MLD and V5, V10, V20, and V30; however, in patients with tumor volume changes of 20% in the third or fourth week of treatment.

  2. Hypofractionated stereotactic photon radiotherapy of posteriorly located choroidal melanoma with five fractions at ten Gy – Clinical results after six years of experience

    Purpose: To evaluate long-term safety and efficacy of hypofractionated stereotactic photon radiotherapy with 5 five fractions at 10 Gy each in patients with centrally located choroidal melanoma. Materials and Methods: Ninety-one patients with centrally located choroidal melanoma were treated stereotactically at a linear accelerator with 6 MV photon beams with 5 fractions at 10 Gy each. Examinations were performed at baseline and every 3 months in the first 2 years, then every 6 months until 5 years and yearly thereafter. Median follow-up was 37.8 months (IQR 19.2–49.9). They included visual acuity assessment, routine ophthalmological examinations with fundoscopy, echography for measurement of tumor dimensions, medical examinations and, if necessary, fluorescein angiography. Results: Initial tumor base diameters, height and volume were 11.20 mm (IQR 9.10–13.70), 9.80 mm (IQR 7.80–11.70), 4.53 mm (IQR 3.33–6.43) and 253.8 mm3 (IQR 127.5–477.0). Local tumor control and eye retention rates were 97.7% and 86.4% after 5 years, respectively. Eight patients developed metastatic disease and 3 of them died due to metastatic disease during the follow-up period. Median visual acuity decreased from 0.67 initially to 0.05 at the last individual follow-up (p < 0.001). The most common toxicities (any grade) were radiation retinopathy (n = 39), optic neuropathy (n = 32), radiogenic cataract (n = 21), neovascular glaucoma (n = 15) and dry eye syndrome (n = 10). The 5 year probabilities to remain free of these side effects (any grade) were 26.0%, 45.4%, 55.4%, 72.6% and 80.5%, respectively. The most important prognostic factors for toxicities were the largest tumor base diameter, tumor height and tumor distance to the optic disk. Conclusion: Hypofractionated stereotactic photon radiotherapy with a total dose of 50 Gy delivered in 5 fractions is a highly effective treatment option in patients with centrally located choroidal melanoma and has a moderate toxicity profile

  3. Output trends, characteristics, and measurements of three megavoltage radiotherapy linear accelerators.

    Hossain, Murshed

    2014-01-01

    The purpose of this study is to characterize and understand the long-term behavior of the output from megavoltage radiotherapy linear accelerators. Output trends of nine beams from three linear accelerators over a period of more than three years are reported and analyzed. Output, taken during daily warm-up, forms the basis of this study. The output is measured using devices having ion chambers. These are not calibrated by accredited dosimetry laboratory, but are baseline-compared against monthly output which is measured using calibrated ion chambers. We consider the output from the daily check devices as it is, and sometimes normalized it by the actual output measured during the monthly calibration of the linacs. The data show noisy quasi-periodic behavior. The output variation, if normalized by monthly measured "real' output, is bounded between ± 3%. Beams of different energies from the same linac are correlated with a correlation coefficient as high as 0.97, for one particular linac, and as low as 0.44 for another. These maximum and minimum correlations drop to 0.78 and 0.25 when daily output is normalized by the monthly measurements. These results suggest that the origin of these correlations is both the linacs and the daily output check devices. Beams from different linacs, independent of their energies, have lower correlation coefficient, with a maximum of about 0.50 and a minimum of almost zero. The maximum correlation drops to almost zero if the output is normalized by the monthly measured output. Some scatter plots of pairs of beam output from the same linac show band-like structures. These structures are blurred when the output is normalized by the monthly calibrated output. Fourier decomposition of the quasi-periodic output is consistent with a 1/f power law. The output variation appears to come from a distorted normal distribution with a mean of slightly greater than unity. The quasi-periodic behavior is manifested in the seasonally averaged output

  4. Randomized Comparison of Whole Brain Radiotherapy, 20 Gy in Four Daily Fractions Versus 40 Gy in 20 Twice-Daily Fractions, for Brain Metastases

    Purpose: The present study compared the intracranial control rate and quality of life for two radiation fractionation schemes for cerebral metastases. Methods and Materials: A total of 113 patients with a Eastern Cooperative Oncology Group performance status 2 months), absent, or concurrent presentation of extracranial disease were randomized to 40 Gy in 20 twice-daily fractions (Arm A) or 20 Gy in four daily fractions (Arm B), stratified by resection status. The European Organization for Research and Treatment of Cancer Quality of Life 30-item questionnaire was administered monthly during Year 1, bimonthly during Year 2, and then every 6 months to Year 5. Results: The patient age range was 28-83 years (mean 62). Of the 113 patients, 41 had undergone surgical resection, and 74 patients had extracranial disease (31 concurrent and 43 stable). The median survival time was 6.1 months in Arm A and 6.6 months in Arm B, and the overall 5-year survival rate was 3.5%. Intracranial progression occurred in 44% of Arm A and 64% of Arm B patients (p = .03). Salvage surgery or radiotherapy was used in 4% of Arm A patients and 21% of Arm B patients (p = .004). Death was attributed to central nervous system progression in 32% of patients in Arm A and 52% of patients in Arm B (p = .03). The toxicity was minimal, with a minor increase in short-term cutaneous reactions in Arm A. The patients' quality of life was not impaired by the more intense treatment in Arm A. Conclusion: Intracranial disease control was improved and the quality of life was maintained with 40 Gy in 20 twice-daily fractions. This schema should be considered for better prognosis subgroups of patients with cerebral metastases.

  5. 18F-EF5 PET Is Predictive of Response to Fractionated Radiotherapy in Preclinical Tumor Models.

    Ali, Rehan; Apte, Sandeep; Vilalta, Marta; Subbarayan, Murugesan; Miao, Zheng; Chin, Frederick T; Graves, Edward E

    2015-01-01

    We evaluated the relationship between pre-treatment positron emission tomography (PET) using the hypoxic tracer 18F-[2-(2-nitro-1-H-imidazol-1-yl)-N-(2,2,3,3,3- pentafluoropropyl) acetamide] (18F-EF5) and the response of preclinical tumor models to a range of fractionated radiotherapies. Subcutaneous HT29, A549 and RKO tumors grown in nude mice were imaged using 18F-EF5 positron emission tomography (PET) in order to characterize the extent and heterogeneity of hypoxia in these systems. Based on these results, 80 A549 tumors were subsequently grown and imaged using 18F-EF5 PET, and then treated with one, two, or four fraction radiation treatments to a total dose of 10-40 Gy. Response was monitored by serial caliper measurements of tumor volume. Longitudinal post-treatment 18F-EF5 PET imaging was performed on a subset of tumors. Terminal histologic analysis was performed to validate 18F-EF5 PET measures of hypoxia. EF5-positive tumors responded more poorly to low dose single fraction irradiation relative to EF5-negative tumors, however both groups responded similarly to larger single fraction doses. Irradiated tumors exhibited reduced 18F-EF5 uptake one month after treatment compared to control tumors. These findings indicate that pre- treatment 18F-EF5 PET can predict the response of tumors to single fraction radiation treatment. However, increasing the number of fractions delivered abrogates the difference in response between tumors with high and low EF5 uptake pre-treatment, in agreement with traditional radiobiology. PMID:26431331

  6. 18F-EF5 PET Is Predictive of Response to Fractionated Radiotherapy in Preclinical Tumor Models.

    Rehan Ali

    Full Text Available We evaluated the relationship between pre-treatment positron emission tomography (PET using the hypoxic tracer 18F-[2-(2-nitro-1-H-imidazol-1-yl-N-(2,2,3,3,3- pentafluoropropyl acetamide] (18F-EF5 and the response of preclinical tumor models to a range of fractionated radiotherapies. Subcutaneous HT29, A549 and RKO tumors grown in nude mice were imaged using 18F-EF5 positron emission tomography (PET in order to characterize the extent and heterogeneity of hypoxia in these systems. Based on these results, 80 A549 tumors were subsequently grown and imaged using 18F-EF5 PET, and then treated with one, two, or four fraction radiation treatments to a total dose of 10-40 Gy. Response was monitored by serial caliper measurements of tumor volume. Longitudinal post-treatment 18F-EF5 PET imaging was performed on a subset of tumors. Terminal histologic analysis was performed to validate 18F-EF5 PET measures of hypoxia. EF5-positive tumors responded more poorly to low dose single fraction irradiation relative to EF5-negative tumors, however both groups responded similarly to larger single fraction doses. Irradiated tumors exhibited reduced 18F-EF5 uptake one month after treatment compared to control tumors. These findings indicate that pre- treatment 18F-EF5 PET can predict the response of tumors to single fraction radiation treatment. However, increasing the number of fractions delivered abrogates the difference in response between tumors with high and low EF5 uptake pre-treatment, in agreement with traditional radiobiology.

  7. Tracking the dynamic seroma cavity using fiducial markers in patients treated with accelerated partial breast irradiation using 3D conformal radiotherapy

    Yue, Ning J.; Haffty, Bruce G.; Goyal, Sharad [Department of Radiation Oncology, Cancer Institute of New Jersey, UMDNJ/Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903 (United States); Kearney, Thomas; Kirstein, Laurie [Division of Surgical Oncology, Cancer Institute of New Jersey, UMDNJ/Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903 (United States); Chen Sining [Department of Biostatistics, Cancer Institute of New Jersey, UMDNJ/School of Public Health, New Brunswick, NJ 08901 (United States)

    2013-02-15

    Purpose: The purpose of the present study was to perform an analysis of the changes in the dynamic seroma cavity based on fiducial markers in early stage breast cancer patients treated with accelerated partial breast irradiation (APBI) using three-dimensional conformal external beam radiotherapy (3D-CRT). Methods: A prospective, single arm trial was designed to investigate the utility of gold fiducial markers in image guided APBI using 3D-CRT. At the time of lumpectomy, four to six suture-type gold fiducial markers were sutured to the walls of the cavity. Patients were treated with a fractionation scheme consisting of 15 fractions with a fractional dose of 333 cGy. Treatment design and planning followed NSABP/RTOG B-39 guidelines. During radiation treatment, daily kV imaging was performed and the markers were localized and tracked. The change in distance between fiducial markers was analyzed based on the planning CT and daily kV images. Results: Thirty-four patients were simulated at an average of 28 days after surgery, and started the treatment on an average of 39 days after surgery. The average intermarker distance (AiMD) between fiducial markers was strongly correlated to seroma volume. The average reduction in AiMD was 19.1% (range 0.0%-41.4%) and 10.8% (range 0.0%-35.6%) for all the patients between simulation and completion of radiotherapy, and between simulation and beginning of radiotherapy, respectively. The change of AiMD fits an exponential function with a half-life of seroma shrinkage. The average half-life for seroma shrinkage was 15 days. After accounting for the reduction which started to occur after surgery through CT simulation and treatment, radiation was found to have minimal impact on the distance change over the treatment course. Conclusions: Using the marker distance change as a surrogate for seroma volume, it appears that the seroma cavity experiences an exponential reduction in size. The change in seroma size has implications in the size of

  8. Accelerated Hyperfractionated Radiotherapy for Cervical Cancer: Multi-Institutional Prospective Study of Forum for Nuclear Cooperation in Asia Among Eight Asian Countries

    Purpose: To evaluate the toxicity and efficacy of accelerated hyperfractionated radiotherapy (RT) for locally advanced cervical cancer. Methods and Materials: A multi-institutional prospective single-arm study was conducted among eight Asian countries. Between 1999 and 2002, 120 patients (64 with Stage IIB and 56 with Stage IIIB) with squamous cell carcinoma of the cervix were treated with accelerated hyperfractionated RT. External beam RT consisted of 30 Gy to the whole pelvis, 1.5 Gy/fraction twice daily, followed by 20 Gy of pelvic RT with central shielding at a dose of 2-Gy fractions daily. A small bowel displacement device was used with the patient in the prone position. In addition to central shielding RT, intracavitary brachytherapy was started. Acute and late morbidities were graded according to the Radiation Therapy Oncology Group and Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria. Results: The median overall treatment time was 35 days. The median follow-up time for surviving patients was 4.7 years. The 5-year pelvic control and overall survival rate for all patients was 84% and 70%, respectively. The 5-year pelvic control and overall survival rate was 78% and 69% for tumors ≥6 cm in diameter, respectively. No treatment-related death occurred. Grade 3-4 late toxicities of the small intestine, large intestine, and bladder were observed in 1, 1, and 2 patients, respectively. The 5-year actuarial rate of Grade 3-4 late toxicity at any site was 5%. Conclusion: The results of our study have shown that accelerated hyperfractionated RT achieved sufficient pelvic control and survival without increasing severe toxicity. This treatment could be feasible in those Asian countries where chemoradiotherapy is not available

  9. Single-Fraction Intraoperative Radiotherapy for Breast Cancer: Early Cosmetic Results

    Purpose: To evaluate the cosmetic outcome of patients treated with wide local excision and intraoperative radiotherapy for early-stage breast cancer. Methods and Materials: A total of 50 women were treated on a pilot study to evaluate the feasibility of intraoperative radiotherapy at wide local excision. The eligibility criteria included age >60, tumor size ≤2.0 cm, clinically negative lymph nodes, and biopsy-established diagnosis. After wide local excision, a custom breast applicator was placed in the excision cavity, and a dose of 20 Gy was prescribed to a depth of 1 cm. After 18 patients were treated, the dose was constrained laterally to 18 Gy. The cosmetic outcome was evaluated by photographs at baseline and at 6 and 12 months postoperatively. Four examiners graded the photographs for symmetry, edema, discoloration, contour, and scarring. The grades were evaluated in relationship to the volume of irradiated tissue, tumor location, and dose at the lateral aspects of the cavity. Results: The median volume of tissue receiving 100% of the prescription dose was 47 cm3 (range, 20-97 cm3). Patients with ≤47 cm3 of treated tissue had better cosmetic outcomes than did the women who had >47 cm3 of treated tissue. Women who had received 18 Gy at the lateral aspects of their cavities had better cosmetic outcomes than did women who had received 20 Gy at the lateral aspects. When comparing the 6- and 12-month results, the scores remained stable for 63%, improved for 17%, and worsened for 20%. Conclusion: Intraoperative radiotherapy appears feasible for selected patients. A favorable cosmetic outcome appears to be related to a smaller treatment volume. The cosmetic outcome is acceptable, although additional follow-up is necessary

  10. A study on the potential of cell kinetically directed fractionation schemes in radiotherapy

    In this thesis, the phenomenon of radiation-induced synchronization of cells into the radiosensitive G2 phase of the cell cycle and the exploitation of this phenomenon to enhance the efficacy of frationated radiotherapy was investigated. A nude mouse model was used to investigate the cell kinetics of 6 human xenotransplanted tumours before and after irradiation. In the second part of the investigation it was tested whether split dose irradiation intervals, based on cell kinetic data of the tumours (i.e. timing of maximal accumulation of cells in G2) would result in an enhanced response compared with those at non optimal intervals (author), 297 refs.; 35 figs.; 25 tabs

  11. Long term outcome of adolescent and adult patients with pineal parenchymal tumors treated with fractionated radiotherapy between 1982 and 2003 -- a single institution's experience

    To evaluate the effectivity of fractionated radiotherapy in adolescent and adult patients with pineal parenchymal tumors (PPT). Between 1982 and 2003, 14 patients with PPTs were treated with fractionated radiotherapy. 4 patients had a pineocytoma (PC), one a PPT with intermediate differentiation (PPTID) and 9 patients a pineoblastoma (PB), 2 of which were recurrences. All patients underwent radiotherapy on the primary tumor site with a median total dose of 54 Gy. In 9 patients with primary PB treatment included whole brain irradiation (3 patients) or irradiation of the craniospinal axis (6 patients) with a median total dose of 35 Gy. Median follow-up was 123 months in the PC patients and 109 months in the patients with primary PB. 7 patients were free from relapse at the end of follow-up. One PC patient died from spinal seeding. Among 5 PB patients treated with radiotherapy without chemotherapy, 3 developed local or spinal tumor recurrence. Both patients treated for PB recurrences died. The patient with PPTID is free of disease 7 years after radiotherapy. Local radiotherapy seems to be effective in patients with PC and some PPTIDs. Diagnosis and treatment of patients with more aggressive variants of PPTIDs as well as treatment of PB needs to be further improved, since local and spinal failure even despite craniospinal irradiation (CSI) is common. As PPT are very rare tumors, treatment within multi-institutional trials remains necessary

  12. Rapidly alternating combination of cisplatin-based chemotherapy and hyperfractionated accelerated radiotherapy in split course for Stage IIIA and Stage IIIB non-small cell lung cancer: results of a Phase I-II study by the GOTHA group

    Alberto, P.; Mermillod, B. [Hopital Cantonal Geneve, Geneva (Switzerland); Mirimanoff, R.O.; Leyvraz, S.; Nagy-Mignotte, H.; Bolla, M.; Wellmann, D.; Moro, D.; Brambilla, E. [Hopital Cantonal Universitaire, Lausanne (Switzerland)

    1995-08-01

    The prognosis of stage III non-small cell lung cancer (NSCLC) can be improved by a combination of radiotherapy (RT) and chemotherapy (CT). In this study, the GOTHA group evaluated the feasibility, tolerance, tumour response, pattern of failure and effect on survival of a combination alternating accelerated hyperfractionated (AH) RT and CT in patients with tumour stage III NSCLC. Toxic effects were leucopenia, nausea and vomiting, mucositis, diarrhoea, alopecia and peripheral neuropathy. Alternating CT and AHRT, as used in this study, were well tolerated and allowed full dose delivery within less than 12 weeks. Initial response was not predictive of survival. The survival curve is encouraging and the 5 year survival is superior to the 5% generally observed with conventionally fractionated radiotherapy. (author).

  13. Changes in cardiac performance and sympathetic stimulation during and after fractionated radiotherapy in a rat model

    The consequences of fractionated irradiation on the number of cardiac α- and β-adrenergic receptors, myocardial norepinephrine concentration and in vitro assessed heart function were studied in Sprague-Dawley rats. Animals were locally irradiated on the thorax with a total dose of 50 Gy, in 5 weeks, using two different fractionation schemes (5 x 2.0 Gy/week and 3 x 3.3 Gy/week). Functional and biochemical assays were performed during treatment and at 6 months after initiation of treatment. During fractionated irradiation, the numbers of α- and β-adrenergic receptors tended to rise. During this period, myocardial norepinephrine concentration remained fairly constant and no decrease in cardiac output was observed. At 6 months, a significant increase of the numbers of α- and β-adrenergic receptors was observed in the 3.3 Gy/fraction group compared to age-matched controls, p = 0.012 and p = 0.02, respectively. At this time point, the myocardial norepinephrine concentration had decreased below control levels (p = 0.008 for the 3.3. Gy/fraction schedule, and p = 0.03 for the 2.0 Gy/fraction schedule). At 6 months, the cardiac output declined to 61% (p = 0.009) and 69% (p = 0.04) of control values for the 3.3 and 2.0 Gy/fraction schedules, respectively. The present data clearly show development of late cardiac sequelae caused by fractionated thorax irradiation with a total dose of 50 Gy. Moreover, this study lends support to the importance of fraction size with regard to the severity of the radiation-induced cardiac damage

  14. Simultaneous optimization of dose distributions and fractionation schemes in particle radiotherapy

    Unkelbach, Jan; Zeng, Chuan [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Engelsman, Martijn [Faculty of Applied Physics, Delft University of Technology/HollandPTC, 2628 CJ Delft (Netherlands)

    2013-09-15

    Purpose: The paper considers the fractionation problem in intensity modulated proton therapy (IMPT). Conventionally, IMPT fields are optimized independently of the fractionation scheme. In this work, we discuss the simultaneous optimization of fractionation scheme and pencil beam intensities.Methods: This is performed by allowing for distinct pencil beam intensities in each fraction, which are optimized using objective and constraint functions based on biologically equivalent dose (BED). The paper presents a model that mimics an IMPT treatment with a single incident beam direction for which the optimal fractionation scheme can be determined despite the nonconvexity of the BED-based treatment planning problem.Results: For this model, it is shown that a small α/β ratio in the tumor gives rise to a hypofractionated treatment, whereas a large α/β ratio gives rise to hyperfractionation. It is further demonstrated that, for intermediate α/β ratios in the tumor, a nonuniform fractionation scheme emerges, in which it is optimal to deliver different dose distributions in subsequent fractions. The intuitive explanation for this phenomenon is as follows: By varying the dose distribution in the tumor between fractions, the same total BED can be achieved with a lower physical dose. If it is possible to achieve this dose variation in the tumor without varying the dose in the normal tissue (which would have an adverse effect), the reduction in physical dose may lead to a net reduction of the normal tissue BED. For proton therapy, this is indeed possible to some degree because the entrance dose is mostly independent of the range of the proton pencil beam.Conclusions: The paper provides conceptual insight into the interdependence of optimal fractionation schemes and the spatial optimization of dose distributions. It demonstrates the emergence of nonuniform fractionation schemes that arise from the standard BED model when IMPT fields and fractionation scheme are optimized

  15. Clinical radiobiology of glioblastoma multiforme. Estimation of tumor control probability from various radiotherapy fractionation schemes

    Pedicini, Piernicola [I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Unit of Nuclear Medicine, Department of Radiation and Metabolic Therapies, Rionero-in-Vulture (Italy); Department of Radiation and Metabolic Therapies, I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Unit of Radiotherapy, Rionero-in-Vulture (Italy); Fiorentino, Alba [Sacro Cuore - Don Calabria Hospital, Radiation Oncology Department, Negrar, Verona (Italy); Simeon, Vittorio [I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Laboratory of Preclinical and Translational Research, Rionero-in-Vulture (Italy); Tini, Paolo; Pirtoli, Luigi [University of Siena and Tuscany Tumor Institute, Unit of Radiation Oncology, Department of Medicine Surgery and Neurological Sciences, Siena (Italy); Chiumento, Costanza [Department of Radiation and Metabolic Therapies, I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Unit of Radiotherapy, Rionero-in-Vulture (Italy); Salvatore, Marco [I.R.C.C.S. SDN Foundation, Unit of Nuclear Medicine, Napoli (Italy); Storto, Giovanni [I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Unit of Nuclear Medicine, Department of Radiation and Metabolic Therapies, Rionero-in-Vulture (Italy)

    2014-10-15

    The aim of this study was to estimate a radiobiological set of parameters from the available clinical data on glioblastoma (GB). A number of clinical trial outcomes from patients affected by GB and treated with surgery and adjuvant radiochemotherapy were analyzed to estimate a set of radiobiological parameters for a tumor control probability (TCP) model. The analytical/graphical method employed to fit the clinical data allowed us to estimate the intrinsic tumor radiosensitivity (α), repair capability (b), and repopulation doubling time (T{sub d}) in a first phase, and subsequently the number of clonogens (N) and kick-off time for accelerated proliferation (T{sub k}). The results were used to formulate a hypothesis for a scheduleexpected to significantly improve local control. The 95 % confidence intervals (CI{sub 95} {sub %}) of all parameters are also discussed. The pooled analysis employed to estimate the parameters summarizes the data of 559 patients, while the studies selected to verify the results summarize data of 104 patients. The best estimates and the CI{sub 95} {sub %} are α = 0.12 Gy{sup -1} (0.10-0.14), b = 0.015 Gy{sup -2} (0.013-0.020), α/b = 8 Gy (5.0-10.8), T{sub d} = 15.4 days (13.2-19.5), N = 1 . 10{sup 4} (1.2 . 10{sup 3} - 1 . 10{sup 5}), and T{sub k} = 37 days (29-46). The dose required to offset the repopulation occurring after 1 day (D{sub prolif}) and starting after T{sub k} was estimated as 0.30 Gy/day (0.22-0.39). The analysis confirms a high value for the α/b ratio. Moreover, a high intrinsic radiosensitivity together with a long kick-off time for accelerated repopulation and moderate repopulation kinetics were found. The results indicate a substantial independence of the duration of the overall treatment and an improvement in the treatment effectiveness by increasing the total dose without increasing the dose fraction. (orig.) [German] Schaetzung eines strahlenbiologischen Parametersatzes auf der Grundlage klinischer Daten bei

  16. Oxygenation of tumor recurrences following fractionated radiotherapy of primary tumors. Studies on the rhabdomyosarcoma R1H of the rat

    Background and purpose: tumor oxygenation is well recognized as a major factor of tumor response to radiotherapy. In this respect, a number of studies have examined the response of primary tumors, whereas little is known about the oxygenation of tumor recurrences after radiotherapy. It was the aim of this study to investigate the oxygenation of tumor recurrences after preceding irradiation of the primary tumor. Material and methods: tumor oxygenation in primary tumors and recurrences of rat rhabdomyosarcomas R1H was measured by using pO2 probes and Eppendorf pO2 histography. Primary tumors were irradiated at a 60Co radiotherapy facility with a total dose of 75 Gy, given in 30 fractions over 6 weeks. Oxygenation was measured in R1H tumors before and directly after completion of irradiation. In R1H recurrences oxygenation was determined, when they reached the same size as the previously treated primary tumors (Vo = 3.1 ± 0.5 cm3). Additionally, tumor microvessel density and the intercapillary distance of tumor blood vessels were determined on histological sections using a counting grid. Results: tumor oxygenation in R1H recurrences was significantly lower when compared to primary R1H tumors. In primary tumors a median pO2 of 17 ± 7 mmHg was measured. By contrast, the median pO2 in R1H recurrences was only 5 ± 5 mmHg (p 2 values 2 in the tumor periphery; p = 0.0001) compared with recurrent tumors (68 ± 26) and an enhanced mean distance of tumor blood vessels, especially in the center of the R1H recurrences (184 ± 20 vs. 243 ± 70 mm; p = 0.0001). Conclusion: in R1H rhabdomyosarcomas tumor oxygenation in recurrent tumors following radiation therapy is significantly lower than in primary tumors. This observation has to be taken into account in cases of tumor recurrences where repeated radio-therapy, chemotherapy or combined treatment modalities are used. (orig.)

  17. Oxygenation of tumor recurrences following fractionated radiotherapy of primary tumors. Studies on the rhabdomyosarcoma R1H of the rat

    Kehrl, W. [Dept. of Oto-Rhino-Laryngology, Marienkrankenhaus Hamburg (Germany); Sagowski, C.; Wenzel, S. [Dept. of Oto-Rhino-Laryngology, Univ. Hospital Hamburg-Eppendorf (Germany); Zywietz, F. [Inst. of Biophysics and Radiobiology, Univ. Hospital Hamburg-Eppendorf (Germany)

    2004-06-01

    Background and purpose: tumor oxygenation is well recognized as a major factor of tumor response to radiotherapy. In this respect, a number of studies have examined the response of primary tumors, whereas little is known about the oxygenation of tumor recurrences after radiotherapy. It was the aim of this study to investigate the oxygenation of tumor recurrences after preceding irradiation of the primary tumor. Material and methods: tumor oxygenation in primary tumors and recurrences of rat rhabdomyosarcomas R1H was measured by using pO{sub 2} probes and Eppendorf pO{sub 2} histography. Primary tumors were irradiated at a {sup 60}Co radiotherapy facility with a total dose of 75 Gy, given in 30 fractions over 6 weeks. Oxygenation was measured in R1H tumors before and directly after completion of irradiation. In R1H recurrences oxygenation was determined, when they reached the same size as the previously treated primary tumors (V{sub o} = 3.1 {+-} 0.5 cm{sup 3}). Additionally, tumor microvessel density and the intercapillary distance of tumor blood vessels were determined on histological sections using a counting grid. Results: tumor oxygenation in R1H recurrences was significantly lower when compared to primary R1H tumors. In primary tumors a median pO{sub 2} of 17 {+-} 7 mmHg was measured. By contrast, the median pO{sub 2} in R1H recurrences was only 5 {+-} 5 mmHg (p < 0.05). The high frequency of pO{sub 2} values < 5 mmHg indicated that R1H recurrences were significantly more hypoxic (58 {+-} 5%) in comparison to primary tumors (22 {+-} 4%). The histological sections of the R1H recurrences showed a higher heterogeneity in their tissue structure than primary nonirradiated tumors. The morphometric studies demonstrated a reduced microvessel density (91 {+-} 21/9.04 mm{sup 2} in the tumor periphery; p = 0.0001) compared with recurrent tumors (68 {+-} 26) and an enhanced mean distance of tumor blood vessels, especially in the center of the R1H recurrences (184 {+-} 20

  18. Impact of Schedule Duration on Head and Neck Radiotherapy: Accelerated Tumor Repopulation Versus Compensatory Mucosal Proliferation

    Purpose: To determine how modelled maximum tumor control rates, achievable without exceeding mucositis tolerance (tcpmax-early) vary with schedule duration for head and neck squamous cell carcinoma (HNSCC). Methods and materials: Using maximum-likelihood techniques, we have fitted a range of tcp models to two HNSCC datasets (Withers’ and British Institute of Radiology [BIR]), characterizing the dependence of tcp on duration and equivalent dose in 2 Gy fractions (EQD2). Models likely to best describe future data have been selected using the Akaike information criterion (AIC) and its quasi-AIC extension to overdispersed data. Setting EQD2s in the selected tcp models to levels just tolerable for mucositis, we have plotted tcpmax-early against schedule duration. Results: While BIR dataset tcp fits describe dose levels isoeffective for tumor control as rising significantly with schedule protraction, indicative of accelerated tumor repopulation, repopulation terms in fits to Withers’ dataset do not reach significance after accounting for overdispersion of the data. The tcpmax-early curves calculated from tcp fits to the overall Withers’ and BIR datasets rise by 8% and 0-4%, respectively, between 20 and 50 days duration; likewise, tcpmax-early curves calculated for stage-specific cohorts also generally rise slowly with increasing duration. However none of the increases in tcpmax-early calculated from the overall or stage-specific fits reach significance. Conclusions: Local control rates modeled for treatments which lie just within mucosal tolerance rise slowly but insignificantly with increasing schedule length. This finding suggests that whereas useful gains may be made by accelerating unnecessarily slow schedules until they approach early reaction tolerance, little is achieved by shortening schedules further while reducing doses to remain within mucosal tolerance, an approach that may slightly worsen outcomes.

  19. Local control of T3 carcinomas after accelerated fractionation: a look at the 'gap'

    Purpose: To study the effects of midcourse treatment break or gaps related to the local control of T3 carcinoma of the oropharynx and larynx following accelerated hyperfractionated radiation therapy. Methods and Materials: All patients were treated at the Massachusetts General Hospital from 1979 through 1994 with treatment consisting of 1.6 Gy per fraction, two fractions a day for the treatment of T3 carcinoma of the oropharynx and larynx. They were entered in the head and neck data base. Their treatment dates, treatment breaks, and doses vs. local control were analyzed and compared. A p-value of 0.05 was considered statistically significant. Results: A total of 162 patients were available for review. Due to the acute severe mucosal effects, most of the patients required a midcourse pause or 'break' after a dose of 38.4-48 Gy before treatment could be resumed and completed. The data indicate that (a) prolongation of the treatment gap for more than 14 days, (b) total treatment course longer than 45 days, (c) total dose less than 67 Gy, and (d) male gender adversely affected local control. In spite of the gaps, the female patients with advanced carcinomas enjoyed the benefits of improved local control after the accelerated hyperfractionated radiation therapy. Conclusions: Accelerated hyperfractionation radiation therapy using 1.6 Gy per fraction/twice-a-day (b.i.d.) for a total dose of 70.4 Gy in 6 weeks is effective in achieving high local control of T3 squamous cell carcinoma of the oropharynx and larynx. The midcourse treatment gap should be as short as possible with the projected total dose and time. Should the gaps be unduly prolonged due to various circumstances, further increase in the total dose, for example, 72-75 Gy, and/or increase of the fraction sizes, for example, 1.8-2.0 Gy/f b.i.d. after the gap may be necessary to compensate for the adverse effects of the tumor regeneration from the prolonged gap

  20. Accelerated hyperfractionated intensity-modulated radiotherapy for recurrent/unresectable rectal cancer in patients with previous pelvic irradiation: results of a phase II study

    This study was conducted to investigate the local effects and toxicity of accelerated hyperfractionated intensity-modulated radiotherapy for recurrent/unresectable rectal cancer in patients with previous pelvic irradiation. Twenty-two patients with recurrent/unresectable rectal cancer who previously received pelvic irradiation were enrolled in our single-center trial between January 2007 and August 2012. Reirradiation was scheduled for up to 39 Gy in 30 fractions using intensity-modulated radiotherapy plans. The dose was delivered via a hyperfractionation schedule of 1.3 Gy twice daily. Patient follow-up was performed by clinical examination, CT/MRI, or PET/CT every 3 months for the first 2 years and every 6 months thereafter. Tumor response was evaluated 1 month after reirradiation by CT/MRI based on the RECIST criteria. Adverse events were assessed using the National Cancer Institute (NCI) common toxicity criteria (version 3.0). The median time from the end of the initial radiation therapy to reirradiation was 30 months (range, 18-93 months). Overall local responses were observed in 9 patients (40.9%). None of the patients achieved a complete response (CR), and 9 patients (40.9%) had a partial response (PR). Thirteen patients failed to achieve a clinical response: 12 (54.5%) presented with stable disease (SD) and 1 (4.5%) with progressive disease (PD). Among all the patients who underwent reirradiation, partial or complete symptomatic relief was achieved in 6 patients (27.3%) and 13 patients (59.1%), respectively. Grade 4 acute toxicity and treatment-related deaths were not observed. The following grade 3 acute toxicities were observed: diarrhea (2 patients, 9.1%), cystitis (1 patient, 4.5%), dermatitis (1 patient, 4.5%), and intestinal obstruction (1 patient, 4.5%). Late toxicity was infrequent. Chronic severe diarrhea, small bowel obstruction, and dysuria were observed in 2 (9.1%), 1 (4.5%) and 2 (9.1%) of the patients, respectively. This study showed that

  1. Prospective, longitudinal electroglottographic study of voice recovery following accelerated hypofractionated radiotherapy for T1/T2 larynx cancer

    Background and purpose: To measure voice outcomes following accelerated hypofractionated radiotherapy for larynx cancer. Materials and methods: Twenty-five patients with T1/T2 glottic cancer underwent serial electroglottographic and acoustic analysis (sustained vowel/i/ and connected speech) before radiotherapy and 1, 6 and 12 months post-treatment. Twenty-five normal subjects served as a reference control population. Results: Pre-treatment measures were significantly worse for larynx cancer patients. Median jitter (0.23% vs 0.97%, p = 0.001) and shimmer (0.62 dB vs 0.98 dB, p = 0.05) and differences in data ranges reflected greater frequency and amplitude perturbation in the larynx cancer patients. Pre-treatment Mean Phonation Time (MPT) was significantly reduced (21 s vs 14.8 s, p = 0.002) in larynx cancer patients. There was a trend towards improvement of jitter, shimmer and normalized noise energy at 12 months post-treatment. MPT improved but remained significantly worse than for normal subjects (21 s vs 16.4 s, p = 0.013). Average fundamental frequency resembled normal subjects, including improvement of the measured range (91.4-244.6 Hz in controls vs 100-201 Hz in post-treatment larynx cancer patients). Conclusions: This non-invasive technique effectively measures post-treatment vocal function in larynx cancer patients. This study demonstrated improvement of many key parameters that influence voice function over 12 months after radiotherapy

  2. Volumetric Image Guidance Using Carina vs Spine as Registration Landmarks for Conventionally Fractionated Lung Radiotherapy

    Lavoie, Caroline; Higgins, Jane; Bissonnette, Jean-Pierre [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada); Le, Lisa W. [Department of Biostatistics, Princess Margaret Hospital, Toronto, Ontario, M5G 2M9 (Canada); Sun, Alexander; Brade, Anthony; Hope, Andrew; Cho, John [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada); Bezjak, Andrea, E-mail: andrea.bezjak@rmp.uhn.on.ca [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada)

    2012-12-01

    Purpose: To compare the relative accuracy of 2 image guided radiation therapy methods using carina vs spine as landmarks and then to identify which landmark is superior relative to tumor coverage. Methods and Materials: For 98 lung patients, 2596 daily image-guidance cone-beam computed tomography scans were analyzed. Tattoos were used for initial patient alignment; then, spine and carina registrations were performed independently. A separate analysis assessed the adequacy of gross tumor volume, internal target volume, and planning target volume coverage on cone-beam computed tomography using the initial, middle, and final fractions of radiation therapy. Coverage was recorded for primary tumor (T), nodes (N), and combined target (T+N). Three scenarios were compared: tattoos alignment, spine registration, and carina registration. Results: Spine and carina registrations identified setup errors {>=}5 mm in 35% and 46% of fractions, respectively. The mean vector difference between spine and carina matching had a magnitude of 3.3 mm. Spine and carina improved combined target coverage, compared with tattoos, in 50% and 34% (spine) to 54% and 46% (carina) of the first and final fractions, respectively. Carina matching showed greater combined target coverage in 17% and 23% of fractions for the first and final fractions, respectively; with spine matching, this was only observed in 4% (first) and 6% (final) of fractions. Carina matching provided superior nodes coverage at the end of radiation compared with spine matching (P=.0006), without compromising primary tumor coverage. Conclusion: Frequent patient setup errors occur in locally advanced lung cancer patients. Spine and carina registrations improved combined target coverage throughout the treatment course, but carina matching provided superior combined target coverage.

  3. Fast dose algorithm for generation of dose coverage probability for robustness analysis of fractionated radiotherapy

    Tilly, David; Ahnesjö, Anders

    2015-07-01

    A fast algorithm is constructed to facilitate dose calculation for a large number of randomly sampled treatment scenarios, each representing a possible realisation of a full treatment with geometric, fraction specific displacements for an arbitrary number of fractions. The algorithm is applied to construct a dose volume coverage probability map (DVCM) based on dose calculated for several hundred treatment scenarios to enable the probabilistic evaluation of a treatment plan. For each treatment scenario, the algorithm calculates the total dose by perturbing a pre-calculated dose, separately for the primary and scatter dose components, for the nominal conditions. The ratio of the scenario specific accumulated fluence, and the average fluence for an infinite number of fractions is used to perturb the pre-calculated dose. Irregularities in the accumulated fluence may cause numerical instabilities in the ratio, which is mitigated by regularisation through convolution with a dose pencil kernel. Compared to full dose calculations the algorithm demonstrates a speedup factor of ~1000. The comparisons to full calculations show a 99% gamma index (2%/2 mm) pass rate for a single highly modulated beam in a virtual water phantom subject to setup errors during five fractions. The gamma comparison shows a 100% pass rate in a moving tumour irradiated by a single beam in a lung-like virtual phantom. DVCM iso-probability lines computed with the fast algorithm, and with full dose calculation for each of the fractions, for a hypo-fractionated prostate case treated with rotational arc therapy treatment were almost indistinguishable.

  4. SU-E-T-90: Concrete Forward-Scatter Fractions for Radiotherapy Shielding Applications

    Purpose: There is little instruction within the primary shielding guidance document NCRP 151 for vault designs where the primary beam intercepts the maze. We have conducted a Monte-Carlo study to characterize forward-scattered radiation from concrete barriers with the intent of quantifying what amount of additional shielding outside the primary beam is needed in this situation. Methods: We reproduced our vault in MCNP 5 and simulated spectra obtained from the literature and from our treatment planning system for 10 and 18 MV beams. Neutron and gamma-capture contributions were not simulated. Energy deposited was scored at isocenter in a water phantom, within various cells that comprised the maze, and within cells that comprised the vault door. Tracks were flagged that scattered from within the maze to the door and their contributions were tallied separately. Three different concrete mixtures found in the literature were simulated. An empirically derived analytic equation was used for comparison, utilizing patient scatter fractions to approximate the scatter from concrete. Results: Our simulated data confirms that maze-scattered radiation is a significant contribution to total photon dose at the door. It contributes between 20-35% of the photon shielding workload. Forward-scatter fractions for concrete were somewhat dependent on concrete composition and the relative abundance of higher-Z elements. Scatter fractions were relatively insensitive to changes in the primary photon spectrum. Analytic results were of the same magnitude as simulated results. Conclusions: Forward-scattered radiation from the maze barrier needs to be included in the photon workload for shielding calculations in non-standard vault designs. Scatter fractions will vary with concrete composition, but should be insensitive to spectral changes between machine manufacturers. Further plans for investigation include refined scatter fractions for various concrete compositions, scatter fraction

  5. Volumetric Image Guidance Using Carina vs Spine as Registration Landmarks for Conventionally Fractionated Lung Radiotherapy

    Purpose: To compare the relative accuracy of 2 image guided radiation therapy methods using carina vs spine as landmarks and then to identify which landmark is superior relative to tumor coverage. Methods and Materials: For 98 lung patients, 2596 daily image-guidance cone-beam computed tomography scans were analyzed. Tattoos were used for initial patient alignment; then, spine and carina registrations were performed independently. A separate analysis assessed the adequacy of gross tumor volume, internal target volume, and planning target volume coverage on cone-beam computed tomography using the initial, middle, and final fractions of radiation therapy. Coverage was recorded for primary tumor (T), nodes (N), and combined target (T+N). Three scenarios were compared: tattoos alignment, spine registration, and carina registration. Results: Spine and carina registrations identified setup errors ≥5 mm in 35% and 46% of fractions, respectively. The mean vector difference between spine and carina matching had a magnitude of 3.3 mm. Spine and carina improved combined target coverage, compared with tattoos, in 50% and 34% (spine) to 54% and 46% (carina) of the first and final fractions, respectively. Carina matching showed greater combined target coverage in 17% and 23% of fractions for the first and final fractions, respectively; with spine matching, this was only observed in 4% (first) and 6% (final) of fractions. Carina matching provided superior nodes coverage at the end of radiation compared with spine matching (P=.0006), without compromising primary tumor coverage. Conclusion: Frequent patient setup errors occur in locally advanced lung cancer patients. Spine and carina registrations improved combined target coverage throughout the treatment course, but carina matching provided superior combined target coverage.

  6. Fast dose algorithm for generation of dose coverage probability for robustness analysis of fractionated radiotherapy

    A fast algorithm is constructed to facilitate dose calculation for a large number of randomly sampled treatment scenarios, each representing a possible realisation of a full treatment with geometric, fraction specific displacements for an arbitrary number of fractions. The algorithm is applied to construct a dose volume coverage probability map (DVCM) based on dose calculated for several hundred treatment scenarios to enable the probabilistic evaluation of a treatment plan.For each treatment scenario, the algorithm calculates the total dose by perturbing a pre-calculated dose, separately for the primary and scatter dose components, for the nominal conditions. The ratio of the scenario specific accumulated fluence, and the average fluence for an infinite number of fractions is used to perturb the pre-calculated dose. Irregularities in the accumulated fluence may cause numerical instabilities in the ratio, which is mitigated by regularisation through convolution with a dose pencil kernel.Compared to full dose calculations the algorithm demonstrates a speedup factor of ∼1000. The comparisons to full calculations show a 99% gamma index (2%/2 mm) pass rate for a single highly modulated beam in a virtual water phantom subject to setup errors during five fractions. The gamma comparison shows a 100% pass rate in a moving tumour irradiated by a single beam in a lung-like virtual phantom. DVCM iso-probability lines computed with the fast algorithm, and with full dose calculation for each of the fractions, for a hypo-fractionated prostate case treated with rotational arc therapy treatment were almost indistinguishable. (paper)

  7. Histopathologic validation of 3′-deoxy-3′-18F-fluorothymidine PET for detecting tumor repopulation during fractionated radiotherapy of human FaDu squamous cell carcinoma in nude mice18F-FLT PET repopulation -->

    Background and purpose: FaDu human squamous cell carcinoma (FaDu-hSCC) demonstrates accelerated tumor repopulation during fractionated irradiation with pathological validation (Ki-67 and BrdUrd makers) in a xenograft model system. However, these and other functional assays must be performed ex vivo and post hoc. We propose a novel, in vivo, real-time assay utilizing 18F-FLT PET. Material and methods: Nude mice with FaDu-hSCC were irradiated with 12 or 18 fractions of 1.8 Gy ([Dm] = 3.0 Gy), either daily or every second day. 18F-FLT micro-PET scans were performed at different time points, FLT parameters (SUVmax, SUVmean, and T/NT) were measured. Tumor sections were stained for Ki-67 and BrdUrd, a labeling index (LI) was calculated. Imaging-pathology correlation was determined by comparing FLT parameters and immunohistochemical results. Results: Measured SUVmax, SUVmean and T/NT decreased significantly after daily irradiation with 12 fractions in 12 days (P < 0.05) and 18 fractions in 18 days (P < 0.05). In contrast, these parameters increased in mice treated with 12 fractions in 24 days (P > 0.05) and 18 fractions in 36 days (P > 0.05), suggesting accelerated repopulation. Similarly, Ki-67 and BrdUrd LIs demonstrated significant decreases with daily irradiation (P < 0.05), and increases with every-second-day irradiation (P > 0.05). 18F-FLT parameters correlated strongly with proliferation markers (r2: 0.679–0.879, P < 0.001). Conclusions: 18F-FLT parameters were in good agreement with Ki-67 and BrdUrd Li. These results may support a potential role for 18F-FLT PET in real-time detection of tumor repopulation during fractionated radiotherapy

  8. Predicting Chest Wall Pain From Lung Stereotactic Body Radiotherapy for Different Fractionation Schemes

    Purpose: Recent studies with two fractionation schemes predicted that the volume of chest wall receiving >30 Gy (V30) correlated with chest wall pain after stereotactic body radiation therapy (SBRT) to the lung. This study developed a predictive model of chest wall pain incorporating radiobiologic effects, using clinical data from four distinct SBRT fractionation schemes. Methods and Materials: 102 SBRT patients were treated with four different fractionations: 60 Gy in three fractions, 50 Gy in five fractions, 48 Gy in four fractions, and 50 Gy in 10 fractions. To account for radiobiologic effects, a modified equivalent uniform dose (mEUD) model calculated the dose to the chest wall with volume weighting. For comparison, V30 and maximum point dose were also reported. Using univariable logistic regression, the association of radiation dose and clinical variables with chest wall pain was assessed by uncertainty coefficient (U) and C statistic (C) of receiver operator curve. The significant associations from the univariable model were verified with a multivariable model. Results: 106 lesions in 102 patients with a mean age of 72 were included, with a mean of 25.5 (range, 12–55) months of follow-up. Twenty patients reported chest wall pain at a mean time of 8.1 (95% confidence interval, 6.3–9.8) months after treatment. The mEUD models, V30, and maximum point dose were significant predictors of chest wall pain (p < 0.0005). mEUD improved prediction of chest wall pain compared with V30 (C = 0.79 vs. 0.77 and U = 0.16 vs. 0.11). The mEUD with moderate weighting (a = 5) better predicted chest wall pain than did mEUD without weighting (a = 1) (C = 0.79 vs. 0.77 and U = 0.16 vs. 0.14). Body mass index (BMI) was significantly associated with chest wall pain (p = 0.008). On multivariable analysis, mEUD and BMI remained significant predictors of chest wall pain (p = 0.0003 and 0.03, respectively). Conclusion: mEUD with moderate weighting better predicted chest wall pain

  9. A feasibility study: Selection of a personalized radiotherapy fractionation schedule using spatiotemporal optimization

    Purpose: To investigate the impact of using spatiotemporal optimization, i.e., intensity-modulated spatial optimization followed by fractionation schedule optimization, to select the patient-specific fractionation schedule that maximizes the tumor biologically equivalent dose (BED) under dose constraints for multiple organs-at-risk (OARs). Methods: Spatiotemporal optimization was applied to a variety of lung tumors in a phantom geometry using a range of tumor sizes and locations. The optimal fractionation schedule for a patient using the linear-quadratic cell survival model depends on the tumor and OAR sensitivity to fraction size (α/β), the effective tumor doubling time (Td), and the size and location of tumor target relative to one or more OARs (dose distribution). The authors used a spatiotemporal optimization method to identify the optimal number of fractions N that maximizes the 3D tumor BED distribution for 16 lung phantom cases. The selection of the optimal fractionation schedule used equivalent (30-fraction) OAR constraints for the heart (Dmean ≤ 45 Gy), lungs (Dmean ≤ 20 Gy), cord (Dmax ≤ 45 Gy), esophagus (Dmax ≤ 63 Gy), and unspecified tissues (D05 ≤ 60 Gy). To assess plan quality, the authors compared the minimum, mean, maximum, and D95 of tumor BED, as well as the equivalent uniform dose (EUD) for optimized plans to conventional intensity-modulated radiation therapy plans prescribing 60 Gy in 30 fractions. A sensitivity analysis was performed to assess the effects of Td (3–100 days), tumor lag-time (Tk = 0–10 days), and the size of tumors on optimal fractionation schedule. Results: Using an α/β ratio of 10 Gy, the average values of tumor max, min, mean BED, and D95 were up to 19%, 21%, 20%, and 19% larger than those from conventional prescription, depending on Td and Tk used. Tumor EUD was up to 17% larger than the conventional prescription. For fast proliferating tumors with Td less than 10 days, there was no significant increase in

  10. A feasibility study: Selection of a personalized radiotherapy fractionation schedule using spatiotemporal optimization

    Kim, Minsun, E-mail: mk688@uw.edu; Stewart, Robert D. [Department of Radiation Oncology, University of Washington, Seattle, Washington 98195-6043 (United States); Phillips, Mark H. [Departments of Radiation Oncology and Neurological Surgery, University of Washington, Seattle, Washington 98195-6043 (United States)

    2015-11-15

    Purpose: To investigate the impact of using spatiotemporal optimization, i.e., intensity-modulated spatial optimization followed by fractionation schedule optimization, to select the patient-specific fractionation schedule that maximizes the tumor biologically equivalent dose (BED) under dose constraints for multiple organs-at-risk (OARs). Methods: Spatiotemporal optimization was applied to a variety of lung tumors in a phantom geometry using a range of tumor sizes and locations. The optimal fractionation schedule for a patient using the linear-quadratic cell survival model depends on the tumor and OAR sensitivity to fraction size (α/β), the effective tumor doubling time (T{sub d}), and the size and location of tumor target relative to one or more OARs (dose distribution). The authors used a spatiotemporal optimization method to identify the optimal number of fractions N that maximizes the 3D tumor BED distribution for 16 lung phantom cases. The selection of the optimal fractionation schedule used equivalent (30-fraction) OAR constraints for the heart (D{sub mean} ≤ 45 Gy), lungs (D{sub mean} ≤ 20 Gy), cord (D{sub max} ≤ 45 Gy), esophagus (D{sub max} ≤ 63 Gy), and unspecified tissues (D{sub 05} ≤ 60 Gy). To assess plan quality, the authors compared the minimum, mean, maximum, and D{sub 95} of tumor BED, as well as the equivalent uniform dose (EUD) for optimized plans to conventional intensity-modulated radiation therapy plans prescribing 60 Gy in 30 fractions. A sensitivity analysis was performed to assess the effects of T{sub d} (3–100 days), tumor lag-time (T{sub k} = 0–10 days), and the size of tumors on optimal fractionation schedule. Results: Using an α/β ratio of 10 Gy, the average values of tumor max, min, mean BED, and D{sub 95} were up to 19%, 21%, 20%, and 19% larger than those from conventional prescription, depending on T{sub d} and T{sub k} used. Tumor EUD was up to 17% larger than the conventional prescription. For fast proliferating

  11. Effect of external shielding for neutrons during radiotherapy for prostate cancer, considering the 2300 CD linear accelerator and voxel phantom

    Thalhofer, J. L.; Roque, H. S.; Rebello, W. F.; Correa, S. A.; Silva, A. X.; Souza, E. M.; Batita, D. V. S.; Sandrini, E. S.

    2014-02-01

    Photoneutron production occurs when high energy photons, greater than 6.7 MeV, interact with linear accelerator head structures. In Brazil, the National Cancer Institute, one of the centers of reference in cancer treatment, uses radiation at 4 angles (0°, 90°, 180° and 270°) as treatment protocol for prostate cancer. With the objective of minimizing the dose deposited in the patient due to photoneutrons, this study simulated radiotherapy treatment using MCNPX, considering the most realistic environment; simulating the radiotherapy room, the Linac 2300 head, the MAX phantom and the treatment protocol with the accelerator operating at 18 MV. In an attempt to reduce the dose deposited by photoneutrons, an external shielding was added to the Linac 2300. Results show that the equivalent dose due to photoneutrons deposited in the patient diminished. The biggest reduction was seen in bone structures, such as the tibia and fibula, and mandible, at approximately 75%. Besides that, organs such as the brain, pancreas, small intestine, lungs and thyroid revealed a reduction of approximately 60%. It can be concluded that the shielding developed by our research group is efficient in neutron shielding, reducing the dose for the patient, and thus, the risk of secondary cancer, and increasing patient survival rates.

  12. Hyperfractionated Accelerated Radiotherapy (HART) with maintenance chemotherapy for metastatic (M1–3) Medulloblastoma – A safety/feasibility study

    Background and purpose: To evaluate feasibility and toxicity of Hyperfractionated Accelerated Radiotherapy (HART) 1.24 Gy b.i.d. followed by chemotherapy for M1–3 Medulloblastoma (MB). The aim of HART was to use hyperfractionation to improve therapeutic ratio combined with acceleration to minimise tumour cell repopulation during radiotherapy (RT). Materials and methods: Between February 2002 and May 2008, 34 eligible patients (22 male, 12 female) aged 3–15 years (median 7) with metastatic MB (M1–9; M2–3, M3–22) received HART with a craniospinal radiotherapy (CSRT) dose of 39.68 Gy followed by 22.32 Gy boost to the whole posterior fossa and 9.92 Gy metastatic boosts. The 8th and subsequent patients received vincristine (VCR) 1.5 mg/m2 weekly × 8 doses over 8 weeks starting during the 1st week of RT. Maintenance chemotherapy comprised 8 six-weekly cycles of VCR 1.5 mg/m2 weekly × 3, CCNU 75 mg/m2 and cisplatin 70 mg/m2. Results: Median duration of HART was 34 days (range 31–38). Grade 3–4 toxicities included mucositis (8), nausea (10), anaemia (5), thrombocytopaenia (2), leucopaenia (24). With 4.5-year median follow-up, 3-year EFS and OS were 59% and 71%, respectively. Of 10 relapses, 1 was outside the central nervous system (CNS), 1 posterior fossa alone and 8 leptomeningeal with 3 also associated with posterior fossa. Conclusion: HART with or without VCR was well tolerated and may have a place in the multi-modality management of high-risk MB

  13. Fractionated changes in prostate cancer radiotherapy using cone-beam computed tomography

    Huang, Tzung-Chi, E-mail: tzungchi.huang@mail.cmu.edu.tw [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan (China); Department of Biomedical Informatics, Asia University, Taichung City, Taiwan (China); Chou, Kuei-Ting [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan (China); Yang, Shih-Neng [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan (China); Department of Biomedical Informatics, Asia University, Taichung City, Taiwan (China); Chang, Chih-Kai [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan (China); Liang, Ji-An [Department of Radiation Oncology, China Medical University Hospital, Taichung City, Taiwan (China); Zhang, Geoffrey [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States)

    2015-10-01

    The high mobility of the bladder and the rectum causes uncertainty in radiation doses prescribed to patients with prostate cancer who undergo radiotherapy (RT) multifraction treatments. The purpose of this study was to estimate the dose received by the bladder, rectum, and prostate from multifraction treatments using daily cone-beam computed tomography (CBCT). Overall, 28 patients with prostate cancer who planned to receive radiation treatments were enrolled in the study. The acquired CBCT before the treatment delivery was registered with the planning CT to map the dose distribution used in the treatment plan for estimating the received dose during clinical treatment. For all 28 patients with 112 data sets, the mean percentage differences (± standard deviation) in the volume and radiation dose were 44% (± 41) and 18% (± 17) for the bladder, 20% (± 21) and 2% (± 2) for the prostate, and 36% (± 29) and 22% (± 15) for the rectum, respectively. Substantial differences between the volumes and radiation dose and those specified in treatment plans were observed. Besides the use of image-guided RT to improve patient setup accuracy, further consideration of large changes in bladder and rectum volumes is strongly suggested when using external beam radiation for prostate cancer.

  14. Fractionated changes in prostate cancer radiotherapy using cone-beam computed tomography

    The high mobility of the bladder and the rectum causes uncertainty in radiation doses prescribed to patients with prostate cancer who undergo radiotherapy (RT) multifraction treatments. The purpose of this study was to estimate the dose received by the bladder, rectum, and prostate from multifraction treatments using daily cone-beam computed tomography (CBCT). Overall, 28 patients with prostate cancer who planned to receive radiation treatments were enrolled in the study. The acquired CBCT before the treatment delivery was registered with the planning CT to map the dose distribution used in the treatment plan for estimating the received dose during clinical treatment. For all 28 patients with 112 data sets, the mean percentage differences (± standard deviation) in the volume and radiation dose were 44% (± 41) and 18% (± 17) for the bladder, 20% (± 21) and 2% (± 2) for the prostate, and 36% (± 29) and 22% (± 15) for the rectum, respectively. Substantial differences between the volumes and radiation dose and those specified in treatment plans were observed. Besides the use of image-guided RT to improve patient setup accuracy, further consideration of large changes in bladder and rectum volumes is strongly suggested when using external beam radiation for prostate cancer

  15. Elective Lymph Node Irradiation With Intensity-Modulated Radiotherapy: Is Conventional Dose Fractionation Necessary?

    Purpose: Intensity-modulated radiation therapy (IMRT) is the standard of care for head-and-neck cancer (HNC). We treated patients with HNC by delivering either a moderate hypofractionation (MHF) schedule (66 Gy at 2.2 Gy per fraction to the gross tumor [primary and nodal]) with standard dose fractionation (54–60 Gy at 1.8–2.0 Gy per fraction) to the elective neck lymphatics or a conventional dose and fractionation (CDF) schedule (70 Gy at 2.0 Gy per fraction) to the gross tumor (primary and nodal) with reduced dose to the elective neck lymphatics. We analyzed these two cohorts for treatment outcomes. Methods and Materials: Between November 2001 and February 2009, 89 patients with primary carcinomas of the oral cavity, larynx, oropharynx, hypopharynx, and nasopharynx received definitive IMRT with or without concurrent chemotherapy. Twenty patients were treated using the MHF schedule, while 69 patients were treated with the CDF schedule. Patient characteristics and dosimetry plans were reviewed. Patterns of failure including local recurrence (LR), regional recurrence (RR), distant metastasis (DM), disease-free survival (DFS), overall survival (OS), and toxicities, including rate of feeding tube placement and percentage of weight loss, were reviewed and analyzed. Results: Median follow-up was 31.2 months. Thirty-five percent of patients in the MHF cohort and 77% of patients in the CDF cohort received chemotherapy. No RR was observed in either cohort. OS, DFS, LR, and DM rates for the entire group at 2 years were 89.3%, 81.4%, 7.1%, and 9.4%, respectively. Subgroup analysis showed no significant differences in OS (p = 0.595), DFS (p = 0.863), LR (p = 0.833), or DM (p = 0.917) between these two cohorts. Similarly, no significant differences were observed in rates of feeding tube placement and percentages of weight loss. Conclusions: Similar treatment outcomes were observed for MHF and CDF cohorts. A dose of 50 Gy at 1.43 Gy per fraction may be sufficient to

  16. Whole-abdomen radiotherapy for non-Hodgkin's lymphoma using twice-daily fractionation

    Purpose: To report the tolerability and efficacy of twice-daily whole-abdomen irradiation (WAI) for non-Hodgkin's lymphoma (NHL). Methods and Materials: Of 123 patients treated for NHL with WAI, 37% received previous chemotherapy, 28% received WAI as part of comprehensive lymphatic irradiation (CLI), and 32% received WAI for palliation. The median dose to the whole abdomen was 25.0 Gy, followed by a median tumor boost of 9.8 Gy in 58 patients. Fractionation was 1.0 Gy once daily (54%) or 0.8 Gy twice daily (46%). Blood counts were measured weekly. Results: At a median follow-up of 4.3 years, local control was 72% and overall survival was 55% at 5 years. Median time of WAI was 42 days for once-daily treatment and 32 days for twice-daily treatment. Patients receiving twice-daily WAI did not have a significantly higher rate of acute side effects (e.g., nausea, diarrhea, platelet or red blood cell toxicity). Overall, acute thrombocytopenia was the most frequent side effect of treatment; 24 of 96 patients (25%) with available hematologic data had Grade 3+ toxicity. There was no acute Grade 3 gastrointestinal toxicity and no late small bowel obstruction. Multiple regression indicated that patients with four or less involved sites and disease size ≤6 cm had improved local control and overall survival. Conclusions: Twice-daily WAI using 0.8 Gy/fraction does not appear to have any greater toxicity compared with once-daily treatment using 1 Gy/fraction. Small doses per fraction (0.8-1 Gy/fx) are effective, tolerated well in the acute setting, and associated with a low rate of late toxicity

  17. Fractionated stereotactic radiotherapy for vestibular schwannoma (VS): Comparison between cystic-type and solid-type VS

    Purpose: To compare the effectiveness and complications of fractionated stereotactic radiotherapy (SRT) for cystic-type vestibular schwannoma (VS) with those of solid-type VS. Methods and Materials: In 65 patients treated with fractionated SRT between 1991 and 1999, 20 were diagnosed with cystic VS, in which at least one-third of the tumor volume was a cystic component on magnetic resonance imaging (MRI), and 45 were diagnosed with solid VS. Thirty-six Gy to 50 Gy in 20-25 fractions was administered to the isocenter and approximately 80% of the periphery of the tumor. All cystic and solid components were included in the gross tumor volume. The mean follow-up period was 37 months, ranging from 6 to 97 months. Results: The actuarial 3-year rate of no episode of enlargement greater than 2.0 mm was 55% for cystic-type and 75% for solid-type VS; the difference was statistically significant (p 0.023). The actuarial 3-year tumor-reduction (reduction in tumor size greater than 2.0 mm) rates were 93% and 31%, respectively (p = 0.0006). The overall actuarial tumor control rate (no tumor growth greater than 2.0 mm after 2 years or no requirement of salvage surgery) was 92% at 5 years in 44 patients with a follow-up period of 2 or more years. There was no difference in the class hearing preservation rate between cystic VS and solid VS. No permanent trigeminal or facial nerve palsy was observed in either group. Conclusion: Transient tumor enlargement occurs in cystic VS more frequently than in solid-type VS, but the subsequent tumor-reduction rate in cystic VS is better.

  18. High-Dose, Single-Fraction Image-Guided Intensity-Modulated Radiotherapy for Metastatic Spinal Lesions

    Purpose: To report tumor control and toxicity for patients treated with image-guided intensity-modulated radiotherapy (RT) for spinal metastases with high-dose single-fraction RT. Methods and Materials: A total of 103 consecutive spinal metastases in 93 patients without high-grade epidural spinal cord compression were treated with image-guided intensity-modulated RT to doses of 18-24 Gy (median, 24 Gy) in a single fraction between 2003 and 2006. The spinal cord dose was limited to a 14-Gy maximal dose. The patients were prospectively examined every 3-4 months with clinical assessment and cross-sectional imaging. Results: The overall actuarial local control rate was 90% (local failure developed in 7 patients) at a median follow-up of 15 months (range, 2-45 months). The median time to local failure was 9 months (range, 2-15 months) from the time of treatment. Of the 93 patients, 37 died. The median overall survival was 15 months. In all cases, death was from progression of systemic disease and not local failure. The histologic type was not a statistically significant predictor of survival or local control. The radiation dose was a significant predictor of local control (p = 0.03). All patients without local failure also reported durable symptom palliation. Acute toxicity was mild (Grade 1-2). No case of radiculopathy or myelopathy has developed. Conclusion: High-dose, single-fraction image-guided intensity-modulated RT is a noninvasive intervention that appears to be safe and very effective palliation for patients with spinal metastases, with minimal negative effects on quality of life and a high probability of tumor control

  19. A retrospective study of the effectiveness of hemostatic radiotherapy with conventional fractionation in patients with advanced cancer

    Nomoto S

    2015-12-01

    Full Text Available The aim of this study was to assess the efficacy of hemostatic radiotherapy (HRT in patients with advanced cancer. Eighteen patients with advanced cancer treated with HRT at the Fukuoka University and Kyushu Rosai Hospitals in Japan between July 2010 and February 2015 were retrospectively assessed. The hemostatic effect of tumor-related bleeding was assessed by the clinical course of bleeding, laboratory data, the endoscopic study, and the number of blood transfusion units (BTRUs for one month before and after HRT. The median follow-up time was 2.6 months (range, 0.7 to 36.2 months. The median age of the patients was 77 years (range, 51 to 93. The primary diseases with tumor-related bleeding included gastric cancer, urinary bladder cancer, gynecological cancer, prostate cancer, non-small-cell lung cancer, and breast cancer. The median overall survival time was three months, and the one year survival rate was 22.9% of all patients. The HRT regimens ranged from 30 Gy in 10 fractions to 40 Gy in 20 fractions. In all patients, the anemia grade and the number of BTRUs decreased for 1 month after RT. The percentage of patients who were diagnosed as “successful” for hemostasis was 83% (15 of 18 patients. HRT is therefore strongly suggested as effective for the control of tumor-related bleeding in patients with advanced cancer. The optimal radiation doses and fractions are controversial; however, this treatment should be offered for patients with a poor life expectancy.

  20. Hypo-fractionated stereotactic radiotherapy alone using volumetric modulated arc therapy for patients with single, large brain metastases unsuitable for surgical resection

    Navarria, Pierina; Pessina, Federico; Cozzi, Luca; Ascolese, Anna Maria; De Rose, Fiorenza; Fogliata, Antonella; Franzese, Ciro; Franceschini, Davide; Tozzi, Angelo; D’Agostino, Giuseppe; Comito, Tiziana; Iftode, Cristina; Maggi, Giulia; Reggiori, Giacomo; Bello, Lorenzo

    2016-01-01

    Background Hypo-fractionated stereotactic radiotherapy (HSRT) is emerging as a valid treatment option for patients with single, large brain metastases (BMs). We analyzed a set of our patients treated with HSRT. The aim of this study was to evaluate local control (LC), brain distant progression (BDP), toxicity and overall survival (OS). Methods From July 2011 to May 2015, 102 patients underwent HSRT consisting of 27Gy/3fractions for lesions 2.1–3 cm and 32Gy/4 fractions for lesions 3.1–5 cm. L...

  1. Effect of fractionated radiotherapy on the parotid gland: an experimental study in Brazilian minipigs

    Stramandinoli-Zanicotti, Roberta Targa

    2013-04-01

    Full Text Available Introduction: Radiotherapy (RT of head and neck neoplasms often damages the salivary glands. Aim: To examine the pattern of morphologic changes resulting from RT of the head and neck region in minipig parotid glands in a clinical and experimental research setting. Methods: Twelve 18-month-old male Brazilian minipigs weighing 30-40 kg were selected. Eight minipigs were assigned to the experimental group (group 1 and 4 to the control group (group 2. The RT was performed under general anesthesia at Erasto Gaertner Hospital, Curitiba, Brazil, using an á/â ratio of 2.5. The minipigs from group 1 underwent 3 sessions of irradiation with Cobalt 60 of the head and neck, bilaterally, with 3 exposures of 8 Gy each at 7-day intervals for a total dose of 24 Gy. The animals were sacrificed 12 weeks post-RT. Results: The irradiated parotid glands displayed reductions in the size and number of acini as well as loss of secretory granules. The presence of fibrosis and loss of parenchyma relative to non-irradiated glands were observed, with an average reduction in volume of 54%. Conclusions: Our results demonstrate that this model for parotid gland damage resulting from an RT regimen appears to be useful for preclinical large animal studies of RT-induced damage and testing novel potential treatment options. Although recent advances in radiation therapy, such as intensity-modulated radiation therapy, have reduced the dose and limited the field of radiation, considerable salivary gland injury still occurs and can greatly impact the patient's quality of life after cancer treatment.

  2. TH-E-BRF-06: Kinetic Modeling of Tumor Response to Fractionated Radiotherapy

    Purpose: Accurate calibration of radiobiological parameters is crucial to predicting radiation treatment response. Modeling differences may have a significant impact on calibrated parameters. In this study, we have integrated two existing models with kinetic differential equations to formulate a new tumor regression model for calibrating radiobiological parameters for individual patients. Methods: A system of differential equations that characterizes the birth-and-death process of tumor cells in radiation treatment was analytically solved. The solution of this system was used to construct an iterative model (Z-model). The model consists of three parameters: tumor doubling time Td, half-life of dying cells Tr and cell survival fraction SFD under dose D. The Jacobian determinant of this model was proposed as a constraint to optimize the three parameters for six head and neck cancer patients. The derived parameters were compared with those generated from the two existing models, Chvetsov model (C-model) and Lim model (L-model). The C-model and L-model were optimized with the parameter Td fixed. Results: With the Jacobian-constrained Z-model, the mean of the optimized cell survival fractions is 0.43±0.08, and the half-life of dying cells averaged over the six patients is 17.5±3.2 days. The parameters Tr and SFD optimized with the Z-model differ by 1.2% and 20.3% from those optimized with the Td-fixed C-model, and by 32.1% and 112.3% from those optimized with the Td-fixed L-model, respectively. Conclusion: The Z-model was analytically constructed from the cellpopulation differential equations to describe changes in the number of different tumor cells during the course of fractionated radiation treatment. The Jacobian constraints were proposed to optimize the three radiobiological parameters. The developed modeling and optimization methods may help develop high-quality treatment regimens for individual patients

  3. Combined modality treatment of the rhabdomyosarcoma R1H of the rat: tumor and normal tissue response after cisplatin and conventional or accelerated irradiation treatment

    Purpose: To test the importance of the sequence of cisplatin and irradiation, either conventional or accelerated fractionated. Methods and Materials: 30 fractions of 2 Gy were given in 6 or 3 weeks preceded or followed by (time interval between cisplatin and radiotherapy: 3 days) a single IP dose of 5 mg/kg cisplatin in the rhabdomyosarcoma R1H of the rat. Survival curves were generated, and comparisons were made by the log-rank test. Results: After 60 Gy in 6 weeks, no local tumor controls were observed. If cisplatin was injected 3 days before start of 60 Gy/6 weeks, 11 ± 10% (mean ± SE) of the tumors were controlled. Cisplatin after radiotherapy resulted in 50 ± 14% local controls. The difference was significant (p 0.01) for cisplatin after radiotherapy in comparison to radiotherapy alone where no local controls were observed. After accelerated fractionation, 57 ± 19% of the animals were cured with or without cisplatin before radiotherapy. If the drug was injected after end of 60 Gy/3 weeks, 86 ± 13% survived recurrence free. The difference to accelerated radiotherapy alone was not significant. Accelerated radiotherapy produced significantly higher control rates than conventional radiotherapy (p < 0.001). Conclusions: Accelerated radiotherapy resulted in higher local tumor control rates as compared to conventional fractionated irradiation. Cisplatin combined with radiotherapy showed significantly better results if given after but not before irradiation, either conventional or accelerated fractionated

  4. Repopulation of interacting tumor cells during fractionated radiotherapy: Stochastic modeling of the tumor control probability

    Fakir, Hatim [London Health Sciences Center, London, Ontario N6A 5W9 (Canada); Hlatky, Lynn [Center of Cancer Systems Biology, GRI, Tufts University School of Medicine, Boston, Massachusetts 02135 (United States); Li, Huamin; Sachs, Rainer, E-mail: sachs@math.berkeley.edu [Department Mathematics, University of California, Berkeley, California 94720 (United States)

    2013-12-15

    Purpose: Optimal treatment planning for fractionated external beam radiation therapy requires inputs from radiobiology based on recent thinking about the “five Rs” (repopulation, radiosensitivity, reoxygenation, redistribution, and repair). The need is especially acute for the newer, often individualized, protocols made feasible by progress in image guided radiation therapy and dose conformity. Current stochastic tumor control probability (TCP) models incorporating tumor repopulation effects consider “stem-like cancer cells” (SLCC) to be independent, but the authors here propose that SLCC-SLCC interactions may be significant. The authors present a new stochastic TCP model for repopulating SLCC interacting within microenvironmental niches. Our approach is meant mainly for comparing similar protocols. It aims at practical generalizations of previous mathematical models. Methods: The authors consider protocols with complete sublethal damage repair between fractions. The authors use customized open-source software and recent mathematical approaches from stochastic process theory for calculating the time-dependent SLCC number and thereby estimating SLCC eradication probabilities. As specific numerical examples, the authors consider predicted TCP results for a 2 Gy per fraction, 60 Gy protocol compared to 64 Gy protocols involving early or late boosts in a limited volume to some fractions. Results: In sample calculations with linear quadratic parameters α = 0.3 per Gy, α/β = 10 Gy, boosting is predicted to raise TCP from a dismal 14.5% observed in some older protocols for advanced NSCLC to above 70%. This prediction is robust as regards: (a) the assumed values of parameters other than α and (b) the choice of models for intraniche SLCC-SLCC interactions. However, α = 0.03 per Gy leads to a prediction of almost no improvement when boosting. Conclusions: The predicted efficacy of moderate boosts depends sensitively on α. Presumably, the larger values of α are

  5. Intra-fractional bladder motion and margins in adaptive radiotherapy for urinary bladder cancer

    Grønborg, Caroline; Vestergaard, Anne; Høyer, Morten;

    2015-01-01

    volume (CTV) was delineated in all scans. The t = 0 min scan was then rigidly registered to the planning computed tomography (CT) and plan selections were simulated using the CTV_0 (at t = 0 min). To assess intra-fractional motion, coverage of the CTV_10 (at t = 10 min) was quantified using the applied...... PTV. Population-based margins were calculated using the van Herk margin recipe while patient-specific margins were calculated using a linear model. RESULTS: For 49% of the cases, the CTV_10 extended more than 5 mm outside the CTV_0. However, in 58 of the 61 cases (97%) CTV_10 was covered...

  6. Hippocampal Dosimetry Predicts Neurocognitive Function Impairment After Fractionated Stereotactic Radiotherapy for Benign or Low-Grade Adult Brain Tumors

    Gondi, Vinai [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Hermann, Bruce P. [Department of Neurology, University of Wisconsin, Madison, WI (United States); Mehta, Minesh P. [Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL (United States); Tome, Wolfgang A., E-mail: tome@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Department of Biomedical Engineering, University of Wisconsin, Madison, WI (United States)

    2013-02-01

    Purpose: To prospectively evaluate the association between hippocampal dose and long-term neurocognitive function (NCF) impairment for benign or low-grade adult brain tumors treated with fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Adult patients with benign or low-grade adult brain tumors were treated with FSRT per institutional practice. No attempt was made to spare the hippocampus. NCF testing was conducted at baseline and 18 months follow-up, on a prospective clinical trial. Regression-based standardized z scores were calculated by using similar healthy control individuals evaluated at the same test-retest interval. NCF impairment was defined as a z score {<=}-1.5. After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas, dose-volume histograms were generated for the left and right hippocampi and for the composite pair. Biologically equivalent doses in 2-Gy fractions (EQD{sub 2}) assuming an {alpha}/{beta} ratio of 2 Gy were computed. Fisher's exact test and binary logistic regression were used for univariate and multivariate analyses, respectively. Dose-response data were fit to a nonlinear model. Results: Of 29 patients enrolled in this trial, 18 completed both baseline and 18-month NCF testing. An EQD{sub 2} to 40% of the bilateral hippocampi >7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List (WMS-WL) delayed recall (odds ratio [OR] 19.3; p = 0.043). The association between WMS-WL delayed recall and EQD{sub 2} to 100% of the bilateral hippocampi >0.0 Gy trended to significance (OR 14.8; p = 0.068). Conclusion: EQD{sub 2} to 40% of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low-grade adult brain tumors. Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold

  7. Hippocampal Dosimetry Predicts Neurocognitive Function Impairment After Fractionated Stereotactic Radiotherapy for Benign or Low-Grade Adult Brain Tumors

    Purpose: To prospectively evaluate the association between hippocampal dose and long-term neurocognitive function (NCF) impairment for benign or low-grade adult brain tumors treated with fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Adult patients with benign or low-grade adult brain tumors were treated with FSRT per institutional practice. No attempt was made to spare the hippocampus. NCF testing was conducted at baseline and 18 months follow-up, on a prospective clinical trial. Regression-based standardized z scores were calculated by using similar healthy control individuals evaluated at the same test–retest interval. NCF impairment was defined as a z score ≤−1.5. After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas, dose–volume histograms were generated for the left and right hippocampi and for the composite pair. Biologically equivalent doses in 2-Gy fractions (EQD2) assuming an α/β ratio of 2 Gy were computed. Fisher’s exact test and binary logistic regression were used for univariate and multivariate analyses, respectively. Dose–response data were fit to a nonlinear model. Results: Of 29 patients enrolled in this trial, 18 completed both baseline and 18-month NCF testing. An EQD2 to 40% of the bilateral hippocampi >7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List (WMS-WL) delayed recall (odds ratio [OR] 19.3; p = 0.043). The association between WMS-WL delayed recall and EQD2 to 100% of the bilateral hippocampi >0.0 Gy trended to significance (OR 14.8; p = 0.068). Conclusion: EQD2 to 40% of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low-grade adult brain tumors. Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold, patients should be enrolled in

  8. Effectiveness of surgery and individualized high-dose hyperfractionated accelerated radiotherapy on survival in clinical stage I non-small cell lung cancer. A propensity score matched analysis

    Background and purpose: Surgery is considered the treatment of choice for early-stage non-small cell lung cancer (NSCLC). Patients with poor pulmonary function or other comorbidities are treated with radiotherapy. The objective of this investigation is to compare the 3-year survival of two early-stage NSCLC populations treated in two different hospitals, either by surgical resection (lobectomy) or by individualized high-dose accelerated radiotherapy, after matching patients by propensity scoring analysis. Methods: A retrospective comparative study has been performed on two series of consecutive patients with cytohistological diagnosis of NSCLC, clinically staged IA by means of PET-scan (radiotherapy group) and pathologically staged IA (surgery group). Results: A total of 157 cases were initially selected for the analysis (110 operated and 47 treated by radiotherapy). Patients in the radiotherapy group were older, with higher comorbidity and lower FEV1% with 3-years probability of survival for operated patients higher than that found for patients treated by radiotherapy. After matching by propensity scoring (using age and FEV1%), differences disappear and 3-years probability of survival had no statistical differences. Conclusions: Although this is a non-randomized retrospective analysis, we have not found 3-years survival differences after matching cases between surgery and radiotherapy. Nevertheless, data presented here support the continuous investigation for non-surgical alternatives in this disease.

  9. The Nano-X Linear Accelerator: A Compact and Economical Cancer Radiotherapy System Incorporating Patient Rotation.

    Eslick, Enid M; Keall, Paul J

    2015-10-01

    Rapid technological improvements in radiotherapy delivery results in improved outcomes to patients, yet current commercial systems with these technologies on board are costly. The aim of this study was to develop a state-of-the-art cancer radiotherapy system that is economical and space efficient fitting with current world demands. The Nano-X system is a compact design that is light weight combining a patient rotation system with a vertical 6 MV fixed beam. In this paper, we present the Nano-X system design configuration, an estimate of the system dimensions and its potential impact on shielding cost reductions. We provide an assessment of implementing such a radiotherapy system clinically, its advantages and disadvantages compared to a compact conventional gantry rotating linac. The Nano-X system has several differentiating features from current radiotherapy systems, it is [1] compact and therefore can fit into small vaults, [2] light weight, and [3] engineering efficient, i.e., it rotates a relatively light component and the main treatment delivery components are not under rotation (e.g., DMLCs). All these features can have an impact on reducing the costs of the system. In terms of shielding requirements, leakage radiation was found to be the dominant contributor to the Nano-X vault and as such no primary shielding was necessary. For a low leakage design, the Nano-X vault footprint and concrete volume required is 17 m2 and 35 m3 respectively, compared to 54 m2 and 102 m3 for a conventional compact linac vault, resulting in decreased costs in shielding. Key issues to be investigated in future work are the possible patient comfort concerns associated with the patient rotation system, as well as the magnitude of deformation and subsequent adaptation requirements. PMID:24949649

  10. Comparison of stereotactic radiosurgery and fractionated stereotactic radiotherapy of acoustic neurinomas according to 3-D tumor volume shrinkage and quality of life

    Henzel, Martin; Engenhart-Cabillic, Rita [Dept. of Radiation Oncology, Philipps Univ. Marburg (Germany); Hamm, Klaus; Surber, Gunnar; Kleinert, Gabriele [Dept. of Stereotactic Neurosurgery and Radiosurgery, HELIOS Klinikum, Erfurt (Germany); Sitter, Helmut [Dept. of Theoretical Surgery, Philipps Univ. Marburg (Germany); Gross, Markus W. [Dept. of Radiation Oncology, Philipps Univ. Marburg (Germany); Dept. of Radio-Oncology, Univ. Hospital of Basel (Switzerland)

    2009-09-15

    Background and purpose: stereotactic radiosurgery (SRS) and also fractionated stereotactic radiotherapy (SRT) offer high local control (LC) rates (> 90%). This study aimed to evaluate three-dimensional (3-D) tumor volume (TV) shrinkage and to assess quality of life (QoL) after SRS/SRT. Patients and methods: from 1999 to 2005, 35/74 patients were treated with SRS, and 39/74 with SRT. Median age was 60 years. Treatment was delivered by a linear accelerator. Median single dose was 13 Gy (SRS) or 54 Gy (SRT). Patients were followed up {>=} 12 months after SRS/SRT. LC and toxicity were evaluated by clinical examinations and magnetic resonance imaging. 3-D TV shrinkage was evaluated with the planning system. QoL was assessed using the questionnaire Short Form-36. Results: Median follow-up was 50/36 months (SRS/SRT). Actuarial 5-year freedom from progression/overall survival was 88.1%/100% (SRS), and 87.5%/87.2% (SRT). TV shrinkage was 15.1%/40.7% (SRS/SRT; p = 0.01). Single dose (< 13 Gy) was the only determinant factor for TV shrinkage after SRS (p = 0.001). Age, gender, initial TV, and previous operations did not affect TV shrinkage. Acute or late toxicity ({>=} grade 3) was never seen. Concerning QoL, no significant differences were observed after SRS/SRT. Previous operations and gender did not affect QoL (p > 0.05). Compared with the German normal population, patients had worse values for all domains except for mental health. Conclusion: TV shrinkage was significantly higher after SRT than after SRS. Main symptoms were not affected by SRS/SRT. Retrospectively, QoL was neither affected by SRS nor by SRT. (orig.)

  11. Organ localization in fractionated external beam radiotherapy for early stage prostatic adenocarcinoma

    Purpose: Trends toward higher target doses and more conformal radiation field shaping place strict requirements on geometric localisation of the target and surrounding normal structures. Daily localization of these structures is not possible on a conventional treatment machine. For this reason, margins must be incorporated in the field shaping to accommodate any target or normal structure displacement. There are few studies which examine the magnitude of these displacements. We hypothesize that these uncertainties can be reduced by daily radiographic imaging of bony anatomy as an alternative to skin tattoos. This hypothesis is tested using multiple (15-19) CT scans on five patients receiving external beam radiotherapy of the prostate. Materials and Methods: Five patients were CT scanned in treatment position (with immobilization device) on every second day of their initial XRT course (non-boost). Radiopaque markers were placed on the skin tattoos to make them visible in the CT datasets. The scans were collected on a helical CT scanner (SR-7000, 3mm and 5mm slice thickness, 120kVp) and transferred to a workstation for analysis. The structures (prostate, rectum, bladder, and seminal vesicles) on all 80 CT datasets were contoured (manually) by two physicians. A reference dataset was chosen for each patient. The 3D transformations between the study datasets and the reference set were determined using an automated technique. A separate transformation was determined for the alignment of (i) bone (excluding femora) and (ii) skin marks. The contours from each dataset were then transformed back to the reference dataset. The resulting contours show the position of organ relative to either the skin marks (tattoos) or the bony anatomy. The displacement and distortion of the organs were parameterized by the displacement of the volume edge (AP, LAT, SUP-INF), volume, and center-of-mass (COM). Each calculation was performed for an individual patient. Population averages were also

  12. Determining inter-fractional motion of the uterus using 3D ultrasound imaging during radiotherapy for cervical cancer

    Baker, Mariwan; Jensen, Jørgen Arendt; Behrens, Claus F.

    2014-03-01

    Uterine positional changes can reduce the accuracy of radiotherapy for cervical cancer patients. The purpose of this study was to; 1) Quantify the inter-fractional uterine displacement using a novel 3D ultrasound (US) imaging system, and 2) Compare the result with the bone match shift determined by Cone- Beam CT (CBCT) imaging.Five cervical cancer patients were enrolled in the study. Three of them underwent weekly CBCT imaging prior to treatment and bone match shift was applied. After treatment delivery they underwent a weekly US scan. The transabdominal scans were conducted using a Clarity US system (Clarity® Model 310C00). Uterine positional shifts based on soft-tissue match using US was performed and compared to bone match shifts for the three directions. Mean value (+/-1 SD) of the US shifts were (mm); anterior-posterior (A/P): (3.8+/-5.5), superior-inferior (S/I) (-3.5+/-5.2), and left-right (L/R): (0.4+/-4.9). The variations were larger than the CBCT shifts. The largest inter-fractional displacement was from -2 mm to +14 mm in the AP-direction for patient 3. Thus, CBCT bone matching underestimates the uterine positional displacement due to neglecting internal uterine positional change to the bone structures. Since the US images were significantly better than the CBCT images in terms of soft-tissue visualization, the US system can provide an optional image-guided radiation therapy (IGRT) system. US imaging might be a better IGRT system than CBCT, despite difficulty in capturing the entire uterus. Uterine shifts based on US imaging contains relative uterus-bone displacement, which is not taken into consideration using CBCT bone match.

  13. Prevalence and peak incidence of acute and late normal tissue morbidity in the DAHANCA 6&7 randomised trial with accelerated radiotherapy for head and neck cancer

    Mortensen, Hanna R.; Overgaard, Jens; Specht, Lena;

    2012-01-01

    BACKGROUND AND PURPOSE: The aim of this report was to describe the incidence and prevalence of acute and late morbidity in the DAHANCA 6&7 multicentre randomised trial with accelerated radiotherapy for squamous cell carcinoma of the head and neck. MATERIALS AND METHODS: The DAHANCA 6&7 study...

  14. Dosimetric comparison of the linear accelerators at the University Clinic of Radiotherapy and Oncology in Skopje, Macedonia

    In radiotherapy practice, for various practical reasons it is important to know whether two or more linear accelerators (linacs) are dosimetric matched and whether the patient’s treatment can be shifted from one linac to another without reducing the treatment quality. This work presents the data from the dosimetric comparison of the two Varian Clinacs 23EX and one Varian Clinac iX at the University Clinic of Radiotherapy and Oncology in Skopje. Both Percentage Depth Dose (PDD) and Beam Profile (BP) curves were compared for the photon energies (6MV, 15MV) in use at the clinic. The comparison was performed using the IBA OmniPro Accept 7.4™ software. The results from the comparison of the PDD curves showed that in the clinically significant region the dose differences were smaller than 1%. The results from the comparison of the in line and cross line BP curves showed that in the flattened area the dose differences were smaller than 2.5%, while in the penumbra region they were usually between 2% and 8%, but sometimes up to 21%. This suggests that for treatments where the influence of the penumbra region is small, the three linacs may be considered to be dosimetric matched. For treatments where the influence of the penumbra region is greater, the patient can be switched to another machine only after recalculation of the treatment plan. (Author)

  15. Application Monte Carlo code calculates dose distribution of the emitted photon beams from linear accelerator in case radiotherapy lung cancer

    The dose distribution calculation is one of major steps in cancer radiotherapy. This paper applies Monte Carlo code, MCNP5, in simulation 15 MV photon beams from linear accelerator of General Hospital of Kien Giang in a case treatment of lung cancer. The settings for beam direction, field size and isocenter position used in MCNP5 must be the same as in treatment plan at hospital to ensure the results from MCNP5 are accurate. We also built a program CODIM by using MATLAB® programming software. This program is used to construct digital voxel phantoms from lung CT images obtained from cancer treatment cases at Kien Giang hospital and then simulate the delivered dose of linac in these phantoms by using MCNP5 simulation code. The results show that there is a difference of 5% in comparison to Prowess Panther program - a semi-empirical simulation program which is being used for treatment planning in Kien Giang hospital. (author)

  16. Computer simulation of fractionated radiotherapy: Further results and their relevance to percutaneous irradiation and brachytherapy

    Basing on previous papers, the present communication considers the simulation of the radiotherapeutic treatments of glioblastoma multiforme, rectum adenocarcinoma, and gynaecological tumors of cervix uteri (squamous and adenocarcinoma) in spheroid culture. Starting with a single tumor cell in a nutrient medium and after the corresponding growth of the tumor spheroids, varying irradiation schemes are applied to the carcinoma and are compared with regard to tumor kill effectivity using the LQ-model. The two first-mentioned carcinoma are exposed to the dose fractionation schemes standard-, super-, hyperfractionation, and weekly high single dose. The result is that hyperfractionation (3x1.5 Gy/day) and weekly high single dose (1x6 Gy/week) yield the most effective tumor cell kill. The weekly high single dose may be realized by some different irradiation techniques, e.g. stereotactic irradiation or interstitial high dose rate brachytherapy. The treatment of the cervix uteri tumors is performed by a combined therapy form (high dose rate brachytherapy and percutaneous irradition). A comparing simulation of two typical regimens yield a nearly equivalent tumor kill effectivity. By the integration of in vitro tumor growth and clinical treatment schemes in a computer model, the possibility is made available to test the effectivity of variable regimens with the help of computer experiments. (orig.)

  17. The role of MRI in patients with astrocytoma WHO II treated with fractionated stereotactic radiotherapy

    Plathow, Christian; Zuna, Ivan [Division of Radiation Oncology, German Cancer Research Center, INF 280, 69120, Heidelberg (Germany); Division of Diagnostic Radiology, German Cancer Research Center, INF 280, 69120, Heidelberg (Germany); Lichy, Matthias Philipp; Bachert, Peter; Kauczor, Hans-Ulrich [Division of Diagnostic Radiology, German Cancer Research Center, INF 280, 69120, Heidelberg (Germany)

    2004-04-01

    Aim of this study was to evaluate the role of pre-therapeutic and follow-up MRI in the clinical treatment and outcome in patients with astrocytoma WHO grade II after fractionated stereotactic radiation therapy (FSRT). One hundred thirty-nine patients with histologically proven astrocytoma WHO grade II were treated with FSRT and retrospectively evaluated. All patients had follow-up MRI studies (Gd-DTPA-enhanced T1- and T2-weighted MR images). Progression-free survival (PFS) and overall survival (OS) rates were calculated using the Kaplan-Meier method. Multivariate analysis was performed on five potential MRI related prognosticators. Median follow-up was 3.8 years. Positive contrast enhancement (CM+) prior to FSRT proved to be a significant prognosticator for PFS and OS (p<0.01). Pre-therapeutic oedema on T2-weighted images and multifocality of contrast medium (CM) enhancement did not prove to be significant prognosticators. Also, diameter and volume of CM enhancement showed no significance on clinical outcome. Negative contrast enhancing (CM-) patients developing a de novo CM enhancement during follow-up showed a significantly worse clinical outcome compared with generally CM- patients (p<0.05). Pre-therapeutic CM enhancement and the development of CM-enhancing areas during follow-up are negative prognosticators for PFS and OS. They must be interpreted as signs of secondary malignity. (orig.)

  18. Supratentorial primitive neuroectodermal tumors (S-PNET) in children: A prospective experience with adjuvant intensive chemotherapy and hyperfractionated accelerated radiotherapy

    Purpose: Supratentorial primitive neuroectodermal tumors (S-PNET) are rare and have a grim prognosis, frequently taking an aggressive course with local relapse and metastatic spread. We report the results of a mono-institutional therapeutic trial. Methods and Materials: We enrolled 15 consecutive patients to preradiation chemotherapy (CT) consisting of high-dose methotrexate, high-dose etoposide, high-dose cyclophosphamide, and high-dose carboplatin, craniospinal irradiation (CSI) with hyperfractionated accelerated radiotherapy (HART) plus focal boost, maintenance with vincristine/lomustine or consolidation with high-dose thiotepa followed by autologous stem-cell rescue. Results: Median age was 9 years; 7 were male, 8 female. Site of disease was pineal in 3, elsewhere in 12. Six patients were had no evidence of disease after surgery (NED). Of those with evidence of disease after surgery (ED), 2 had central nervous system spread. Of the 9 ED patients, 2 had complete response (CR) and 2 partial response (PR) after CT, 4 stable disease, and 1 progressive disease. Of the 7 ED patients before radiotherapy, 1 had CR, 4 PR, and 2 minor response, thus obtaining a 44% CR + PR after CT and 71% after HART. Because of rapid progression in 2 of the first 5 patients, high-dose thiotepa was systematically adopted after HART in the subsequent 10 patients. Six of 15 patients relapsed (4 locally, 1 locally with dissemination, 1 with dissemination) a mean of 6 months after starting CT, 2 developed second tumors; 5 of 6 relapsers died at a median of 13 months. Three-year progression-free survival, event-free survival, and overall survival were 54%, 34%, and 61%, respectively. Conclusion: Hyperfractionated accelerated RT was the main tool in obtaining responses in S-PNET; introducing the myeloablative phase improved the prognosis (3/10 vs. 3/5 relapses), though the outcome remained unsatisfactory despite the adoption of this intensive treatment

  19. Hypo-fractionated radiotherapy of breast cancer: long term results of a set of 80 cases treated in the radiotherapy department of the Oran university hospital; Radiotherapie hypofractionnee dans le cancer du sein: resultats a long terme d'une serie de 80 cas traites dans le service de radiotherapie du centre hospitalier universitaire d'Oran

    Boukerche, A.; Yahia, A.; Madouri, R.; Belmiloud, H.; Dali-Youcef, A.F. [Service de radiotherapie, CHU d' Oran, Oran (Algeria)

    2011-10-15

    The authors report the assessment of the local and locoregional control and of the acute and late toxicity of adjuvant hypo-fractionated radiotherapy in breast cancer treatment. During 1998, 80 women have been treated by conservative or radical surgery and hypo-fractionated tele-cobalto-therapy (36 Gy in five fractions of 3 Gy a week, and a boost of 15 Gy in five fractions in case of conservative surgery). Results are discussed in terms of local and locoregional recurrence, tolerance, late toxicity, global survival, and tumour classification. The irradiation scheme seems perfectly achievable but a greater number of patients and a longer follow-up are required to better assess the efficiency and aesthetic results. Short communication

  20. Concurrent hyperfractionated accelerated radiotherapy with 5-FU and once weekly cisplatin in locally advanced head and neck cancer. The 10-year results of a prospective phase II trial

    In this study, the acute toxicity and long-term outcome of a hyperfractionated accelerated chemoradiation regimen with cisplatin/5-fluorouracil (5-FU) in patients with locally advanced squamous cell carcinomas of head and neck were evaluated. From 2000-2002, 38 patients with stage III (5.3 %) and stage IV (94.7 %) head and neck cancer were enrolled in a phase II study. Patients received hyperfractionated-accelerated radiotherapy with 72 Gy in 15 fractions of 2 Gy followed by 1.4 Gy twice daily with concurrent, continuous infusion 5-FU of 600 mg/m2 on days 1-5 and 6 cycles of weekly cisplatin (30 mg/m2). Acute toxicities (CTCAEv2.0), locoregional control (LRC), metastases-free (MFS), and overall survival (OS) were analyzed and exploratively compared with the ARO 95-06 trial. Median follow-up was 11.4 years (95 % CI 8.6-14.2) and mean dose 71.6 Gy. Of the patients, 82 % had 6 (n = 15) or 5 (n = 16) cycles of cisplatin, 5 and 2 patients received 4 and 3 cycles, respectively. Grade 3 anemia, leukopenia, and thrombocytopenia were observed in 15.8, 15.8, and 2.6 %, respectively. Grade 3 mucositis in 50 %, grade 3 and 4 dysphagia in 55 and 13 %. The 2-, 5-, and 10-year LRC was 65, 53.6, and 48.2 %, the MFS was 77.5, 66.7, and 57.2 % and the OS 59.6, 29.2, and 15 %, respectively. Chemoradiation with 5-FU and cisplatin seems feasible and superior in terms of LRC and OS to the ARO 95-06C-HART arm at 2 years. However, this did not persist at the 5- and 10-year follow-ups. (orig.)

  1. IsoBED: a tool for automatic calculation of biologically equivalent fractionation schedules in radiotherapy using IMRT with a simultaneous integrated boost (SIB) technique

    Benassi Marcello; Pedrini Massimo; Abate Armando; Bruzzaniti Vicente; Strigari Lidia

    2011-01-01

    Abstract Background An advantage of the Intensity Modulated Radiotherapy (IMRT) technique is the feasibility to deliver different therapeutic dose levels to PTVs in a single treatment session using the Simultaneous Integrated Boost (SIB) technique. The paper aims to describe an automated tool to calculate the dose to be delivered with the SIB-IMRT technique in different anatomical regions that have the same Biological Equivalent Dose (BED), i.e. IsoBED, compared to the standard fractionation....

  2. High-dose fractionated radiotherapy to 80 Gy for stage I–II medically inoperable non-small-cell lung cancer

    Management of medically inoperable non-small-cell lung cancer (NSCLC) has been historically challenging, with poor rates of local control and disease-specific survival. Nearly all published series of standard fractionation radiotherapy have utilised doses <70 Gy. The present investigation describes disease control and survival outcomes for a large series of patients prescribed high-dose radiotherapy for early-stage NSCLC. Retrospective analysis of disease control and survival outcomes for stages I–II NSCLC patients prescribed ≥70 Gy at 1.8–2.5 Gy per fraction. Between May 1997 and August 2008, 100 primary lung tumours in 98 patients (two metachronous) were eligible for analysis. The median age was 71 years (range 49–93), and 92 patients were considered medically inoperable. Nearly all cases were clinical stage cT1N0 (51 patients) or cT2N0 (35). The median radiotherapy dose prescribed was 80.5 Gy (range 70–90). At a median follow-up of 18 months, 72 patients died (44 of/with disease) and 50 experienced recurrence. The estimated 3-year in-field control, progression-free survival, disease-specific, and overall survival rates were 50, 29, 30 and 24%, respectively. Univariate analyses demonstrated an inverse association between local control and tumour size. Medical inoperability was associated with decreased disease-specific and overall survivals. Patient age and biologically equivalent dose were also associated with overall survival. Disease control and survival of fractionated radiotherapy for early-stage NSCLC remain suboptimal. Medical inoperability is associated with worse overall survival; however, local control remains a predominant pattern of failure despite 80 Gy in standard fractionation, particularly in patients with larger tumour size.

  3. Visual outcome of accelerated fractionated radiation for advanced sinonasal malignancies employing photons/protons

    Purpose: To investigate the visual outcomes of patients with advanced sinonasal malignancies treated with proton/photon accelerated fractionated radiation (AFR). Patients and methods: Between 1991 and 2001, AFR was used to treat 36 patients with advanced stage primary (n = 33) or recurrent (n = 3) nasal or paranasal malignant tumors. Full ophthalmologic follow-up was documented. The median dose to the gross tumor volume (GTV) was 69.6 CGE (range 60.8-77). Visual complications were graded according to the National Cancer Institute Common Toxicity Criteria (CTC) and the late effects of normal tissue (LENT) scoring systems. The median follow-up was 52.4 months (range 17-122.8). Results: Thirteen patients developed late visual/ocular toxicity. Cataracts were LENT grade 1 and 3 in 2 patients and 1 patient, respectively. One LENT grade 1 vascular retinopathy and 1 optic neuropathy were also observed. Three and five patients presented with nasolacrimal duct stenosis (CTC grade 2, 2 patients; CTC grade 3, 1 patient) and dry-eye syndrome (CTC grade 1, 1 patient; CTC grade 2, 4 patients), respectively. The 3- and 5-year probability of LENT/CTC grade ≥2 visual toxicity were 15.8 ± 6.7% and 20.7 ± 7.8%, respectively. Conclusions: AFR for locally advanced nasal cavity and paranasal sinus tumors enables delivery of 70 CGE to the tumor with acceptable ophthalmologic complications

  4. A randomised phase II trial of Stereotactic Ablative Fractionated radiotherapy versus Radiosurgery for Oligometastatic Neoplasia to the lung (TROG 13.01 SAFRON II)

    Siva, Shankar; Kron, Tomas; Bressel, Mathias; Haas, Marion; Mai, Tao; Vinod, Shalini; Sasso, Giuseppe; Wong, Wenchang; Le, Hien; Eade, Thomas; Hardcastle, Nicholas; Chesson, Brent; Pham, Daniel; Høyer, Morten; Montgomery, Rebecca

    2016-01-01

    Background Stereotactic ablative body radiotherapy (SABR) is emerging as a non-invasive method for precision irradiation of lung tumours. However, the ideal dose/fractionation schedule is not yet known. The primary purpose of this study is to assess safety and efficacy profile of single and multi-fraction SABR in the context of pulmonary oligometastases. Methods/Design The TROG 13.01/ALTG 13.001 clinical trial is a multicentre unblinded randomised phase II study. Eligible patients have up to ...

  5. A survival model for fractionated radiotherapy with an application to prostate cancer

    This paper explores the applicability of a mechanistic survival model, based on the distribution of clonogens surviving a course of fractionated radiation therapy, to clinical data on patients with prostate cancer. The study was carried out using data on 1100 patients with clinically localized prostate cancer who were treated with three-dimensional conformal radiation therapy. The patients were stratified by radiation dose (group 1: <67.5 Gy; group 2: 67.5-72.5 Gy; group 3: 72.5-77.5 Gy; group 4: 77.5-87.5 Gy) and prognosis category (favourable, intermediate and unfavourable as defined by pre-treatment PSA and Gleason score). A relapse was recorded when tumour recurrence was diagnosed or when three successive prostate specific antigen (PSA) elevations were observed from a post-treatment nadir PSA level. PSA relapse-free survival was used as the primary end point. The model, which is based on an iterated Yule process, is specified in terms of three parameters: the mean number of tumour clonogens that survive the treatment, the mean of the progression time of post-treatment tumour development and its standard deviation. The model parameters were estimated by the maximum likelihood method. The fact that the proposed model provides an excellent description both of the survivor function and of the hazard rate is prima facie evidence of the validity of the model because closeness of the two survivor functions (empirical and model-based) does not generally imply closeness of the corresponding hazard rates. The estimated cure probabilities for the favourable group are 0.80, 0.74 and 0.87 (for dose groups 1-3, respectively); for the intermediate group: 0.25, 0.51, 0.58 and 0.78 (for dose groups 1-4, respectively) and for the unfavourable group: 0.0, 0.27, 0.33 and 0.64 (for dose groups 1-4, respectively). The distribution of progression time to tumour relapse was found to be independent of prognosis group but dependent on dose. As the dose increases the mean progression

  6. 3D quantitative assessment of response to fractionated stereotactic radiotherapy and single-session stereotactic radiosurgery of vestibular schwannoma

    Schneider, T. [The Johns Hopkins Hospital School of Medicine, Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Neuroradiology, Baltimore, MD (United States); University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Neuroradiology, Hamburg (Germany); Chapiro, J. [The Johns Hopkins Hospital School of Medicine, Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Interventional Radiology, Baltimore, MD (United States); Lin, M. [Philips Research North America, Ultrasound Imaging and Interventions (UII), Briarcliff Manor, NY (United States); Geschwind, J.F. [The Johns Hopkins Hospital School of Medicine, Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Interventional Radiology, Baltimore, MD (United States); Yale University School of Medicine, Department of Radiology and Imaging Science, New Haven, CT (United States); Kleinberg, L. [The Johns Hopkins University School of Medicine, Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD (United States); Rigamonti, D.; Jusue-Torres, I.; Marciscano, A.E. [The Johns Hopkins University School of Medicine, Department of Neurological Surgery, Baltimore, MD (United States); Yousem, D.M. [The Johns Hopkins Hospital School of Medicine, Russell H. Morgan Department of Radiology and Radiological Sciences, Division of Neuroradiology, Baltimore, MD (United States)

    2016-03-15

    To determine clinical outcome of patients with vestibular schwannoma (VS) after treatment with fractionated stereotactic radiotherapy (FSRT) and single-session stereotactic radiosurgery (SRS) by using 3D quantitative response assessment on MRI. This retrospective analysis included 162 patients who underwent radiation therapy for sporadic VS. Measurements on T1-weighted contrast-enhanced MRI (in 2-year post-therapy intervals: 0-2, 2-4, 4-6, 6-8, 8-10, 10-12 years) were taken for total tumour volume (TTV) and enhancing tumour volume (ETV) based on a semi-automated technique. Patients were considered non-responders (NRs) if they required subsequent microsurgical resection or developed radiological progression and tumour-related symptoms. Median follow-up was 4.1 years (range: 0.4-12.0). TTV and ETV decreased for both the FSRT and SRS groups. However, only the FSRT group achieved significant tumour shrinkage (p < 0.015 for TTV, p < 0.005 for ETV over time). The 11 NRs showed proportionally greater TTV (median TTV pre-treatment: 0.61 cm{sup 3}, 8-10 years after: 1.77 cm{sup 3}) and ETV despite radiation therapy compared to responders (median TTV pre-treatment: 1.06 cm{sup 3}; 10-12 years after: 0.81 cm{sup 3}; p = 0.001). 3D quantification of VS showed a significant decrease in TTV and ETV on FSRT-treated patients only. NR had significantly greater TTV and ETV over time. (orig.)

  7. Low-dose fractionated radiotherapy and concomitant chemotherapy for recurrent or progressive glioblastoma. Final report of a pilot study

    Balducci, M.; Diletto, B.; Chiesa, S.; D' Agostino, G.R.; Gambacorta, M.A.; Ferro, M.; Valentini, V. [Catholic University of the Sacred Heart, Department of Radiation Oncology, Rome (Italy); Colosimo, C. [Catholic University of the Sacred Heart, Department of Radiology, Rome (Italy); Maira, G.; Anile, C. [Catholic University of the Sacred Heart, Department of Neurosurgery, Rome (Italy)

    2014-04-15

    Evaluated in this study were the feasibility and the efficacy of concurrent low dose fractionated radiotherapy (LD-FRT) and chemotherapy as palliative treatment for recurrent/progressive glioblastoma multiforme (GBM). Eligible patients had recurrent or progressive GBM, Karnofsky performance status ≥70, prior surgery, and standard radiochemotherapy treatment. Recurrence/progression disease during temozolomide (TMZ) received cisplatin (CDDP; 30 mg/m{sup 2} on days 1, 8, 15), fotemustine (FTM; 40 mg/m{sup 2} on days 2, 9, 16), and concurrent LD-FRT (0.3 Gy twice daily); recurrence/progression after 4 months from the end of adjuvant TMZ were treated by TMZ (150/200 mg/m{sup 2} on days 1-5) concomitant with LD-FRT (0.4 Gy twice daily). Primary endpoints were safety and toxicity. A total of 32 patients were enrolled. Hematologic toxicity G1-2 was observed in 18.7% of patients and G3-4 in 9.4%. One patient (3.1%) had complete response, 3 (9.4%) had partial response, 8 (25%) had stable disease for at least 8 weeks, while 20 patients (62.5%) experienced progressive disease. The clinical benefit was 37.5%. Median progression-free survival (PFS) and overall survival (OS) were 5 and 8 months, respectively. Survival rate at 12 months was of 27.8%. LD-FRT and chemotherapy for recurrent/progressive GBM have a good toxicity profile and clinical outcomes, even though further investigation of this novel palliative treatment approach is warranted. (orig.)

  8. Report on a randomized trial comparing two forms of immobilization of the head for fractionated stereotactic radiotherapy.

    Bednarz, Greg; Machtay, Mitchell; Werner-Wasik, Maria; Downes, Beverly; Bogner, Joachim; Hyslop, Terry; Galvin, James; Evans, James; Curran, Walter; Andrews, David

    2009-01-01

    Fractionated stereotactic radiotherapy (SRT) requires accurate and reproducible immobilization of the patient's head. This randomized study compared the efficacy of two commonly used forms of immobilization used for SRT. Two routinely used methods of immobilization, which differ in their approach to reproduce the head position from day to day, are the Gill-Thomas-Cosman (GTC) frame and the BrainLab thermoplastic mask. The GTC frame fixates on the patient's upper dentition and thus is in direct mechanical contact with the cranium. The BrainLab mask is a two-part masking system custom fitted to the front and back of the patient's head. After patients signed an IRB-approved informed consent form, eligible patients were randomized to either GTC frame or mask for their course of SRT. Patients were treated as per standard procedure; however, prior to each treatment a set of digital kilovolt images (ExacTrac, BrainLabAB, Germany) was taken. These images were fused with reference digitally reconstructed radiographs obtained from treatment planning CT to yield lateral, longitudinal, and vertical deviations of isocenter and head rotations about respective axes. The primary end point of the study was to compare the two systems with respect to mean and standard deviations using the distance to isocenter measure. A total of 84 patients were enrolled (69 patients evaluable with detailed positioning data). A mixed-effect linear regression and two-tiled t test were used to compare the distance measure for both the systems. There was a statistically significant (p < 0.001) difference between mean distances for these systems, suggesting that the GTC frame was more accurate. The mean 3D displacement and standard deviations were 3.17+1.95 mm for mask and 2.00+1.04 mm for frame. Both immobilization techniques were highly effective, but the GTC frame was more accurate. To optimize the accuracy of SRT, daily kilovolt image guidance is recommended with either immobilization system. PMID

  9. 3D quantitative assessment of response to fractionated stereotactic radiotherapy and single-session stereotactic radiosurgery of vestibular schwannoma

    To determine clinical outcome of patients with vestibular schwannoma (VS) after treatment with fractionated stereotactic radiotherapy (FSRT) and single-session stereotactic radiosurgery (SRS) by using 3D quantitative response assessment on MRI. This retrospective analysis included 162 patients who underwent radiation therapy for sporadic VS. Measurements on T1-weighted contrast-enhanced MRI (in 2-year post-therapy intervals: 0-2, 2-4, 4-6, 6-8, 8-10, 10-12 years) were taken for total tumour volume (TTV) and enhancing tumour volume (ETV) based on a semi-automated technique. Patients were considered non-responders (NRs) if they required subsequent microsurgical resection or developed radiological progression and tumour-related symptoms. Median follow-up was 4.1 years (range: 0.4-12.0). TTV and ETV decreased for both the FSRT and SRS groups. However, only the FSRT group achieved significant tumour shrinkage (p < 0.015 for TTV, p < 0.005 for ETV over time). The 11 NRs showed proportionally greater TTV (median TTV pre-treatment: 0.61 cm3, 8-10 years after: 1.77 cm3) and ETV despite radiation therapy compared to responders (median TTV pre-treatment: 1.06 cm3; 10-12 years after: 0.81 cm3; p = 0.001). 3D quantification of VS showed a significant decrease in TTV and ETV on FSRT-treated patients only. NR had significantly greater TTV and ETV over time. (orig.)

  10. Stereotactic radiotherapy of intracranial lesions with micro multi leaf collimator mounted on linear accelerator

    Stereotactic radiotherapy (SRT) is an advancement on three-dimensional conformal radiotherapy (3DCRT) which aims not only to conform the therapeutic dose volume to the shape of the tumor, but also ensures low dose to the other normal tissues. As the therapeutic dose volume tightly covers the tumor, small variation between intended plan and executed plan parameters may lead to significant under-dose of tumor or over-dose of normal tissue, which may result in the failure of the treatment. Therefore, SRT should be carried out through a well-laid out systematic procedure in order to achieve its goal. This paper highlights the systematic procedure and comprehensive quality assurance (QA) involved at various steps of intracranial SRT followed in our hospital and our preliminary experience with brain lab stereotactic system. Of the 18 patients treated so far with SRT, we have analyzed the SRT treatment plans for the first 11 brain tumor patients to highlight the volume of tumor covered by the therapeutic dose and integral dose to other normal tissues. The average gross target volume (GTV) and planning target volume (PTV) treated are 14.07 cc, and 43.72 cc, respectively. Out of the 11 patients treated, 100% volume of PTV is covered by 95% isodose volume in 4 patients, 99% of PTV in another 4 patients and 98% of PTV in the remaining 3 patients. But in all the cases, a minimum volume of 96% of the GTV is adequately covered by 100% dose. The conformity index of PTV varies from 1.27 to 1.56, with a mean value of 1.42. As the target volume decreases from 76 cc to 20 cc, the mean dose within the target volume increases from 1.7 Gy to 1.76 Gy. The average volume of normal brain treated with 80%, 50% and 33% dose are 6.53 cc, 73 cc and 298 cc, respectively. Stereotactic radiotherapy with static beams and micro-multileaf collimator (mMLC) shaped fields gives the flexibility to tailor the irregular shaped target volume, thereby ensuring better dose conformity and homogeneous dose

  11. Review of ultrasound image guidance in external beam radiotherapy part II: intra-fraction motion management and novel applications.

    O'Shea, Tuathan; Bamber, Jeffrey; Fontanarosa, Davide; van der Meer, Skadi; Verhaegen, Frank; Harris, Emma

    2016-04-21

    Imaging has become an essential tool in modern radiotherapy (RT), being used to plan dose delivery prior to treatment and verify target position before and during treatment. Ultrasound (US) imaging is cost-effective in providing excellent contrast at high resolution for depicting soft tissue targets apart from those shielded by the lungs or cranium. As a result, it is increasingly used in RT setup verification for the measurement of inter-fraction motion, the subject of Part I of this review (Fontanarosa et al 2015 Phys. Med. Biol. 60 R77-114). The combination of rapid imaging and zero ionising radiation dose makes US highly suitable for estimating intra-fraction motion. The current paper (Part II of the review) covers this topic. The basic technology for US motion estimation, and its current clinical application to the prostate, is described here, along with recent developments in robust motion-estimation algorithms, and three dimensional (3D) imaging. Together, these are likely to drive an increase in the number of future clinical studies and the range of cancer sites in which US motion management is applied. Also reviewed are selections of existing and proposed novel applications of US imaging to RT. These are driven by exciting developments in structural, functional and molecular US imaging and analytical techniques such as backscatter tissue analysis, elastography, photoacoustography, contrast-specific imaging, dynamic contrast analysis, microvascular and super-resolution imaging, and targeted microbubbles. Such techniques show promise for predicting and measuring the outcome of RT, quantifying normal tissue toxicity, improving tumour definition and defining a biological target volume that describes radiation sensitive regions of the tumour. US offers easy, low cost and efficient integration of these techniques into the RT workflow. US contrast technology also has potential to be used actively to assist RT by manipulating the tumour cell environment and by

  12. Review of ultrasound image guidance in external beam radiotherapy part II: intra-fraction motion management and novel applications

    O'Shea, Tuathan; Bamber, Jeffrey; Fontanarosa, Davide; van der Meer, Skadi; Verhaegen, Frank; Harris, Emma

    2016-04-01

    Imaging has become an essential tool in modern radiotherapy (RT), being used to plan dose delivery prior to treatment and verify target position before and during treatment. Ultrasound (US) imaging is cost-effective in providing excellent contrast at high resolution for depicting soft tissue targets apart from those shielded by the lungs or cranium. As a result, it is increasingly used in RT setup verification for the measurement of inter-fraction motion, the subject of Part I of this review (Fontanarosa et al 2015 Phys. Med. Biol. 60 R77-114). The combination of rapid imaging and zero ionising radiation dose makes US highly suitable for estimating intra-fraction motion. The current paper (Part II of the review) covers this topic. The basic technology for US motion estimation, and its current clinical application to the prostate, is described here, along with recent developments in robust motion-estimation algorithms, and three dimensional (3D) imaging. Together, these are likely to drive an increase in the number of future clinical studies and the range of cancer sites in which US motion management is applied. Also reviewed are selections of existing and proposed novel applications of US imaging to RT. These are driven by exciting developments in structural, functional and molecular US imaging and analytical techniques such as backscatter tissue analysis, elastography, photoacoustography, contrast-specific imaging, dynamic contrast analysis, microvascular and super-resolution imaging, and targeted microbubbles. Such techniques show promise for predicting and measuring the outcome of RT, quantifying normal tissue toxicity, improving tumour definition and defining a biological target volume that describes radiation sensitive regions of the tumour. US offers easy, low cost and efficient integration of these techniques into the RT workflow. US contrast technology also has potential to be used actively to assist RT by manipulating the tumour cell environment and by

  13. PET hypoxia imaging with FAZA: reproducibility at baseline and during fractionated radiotherapy in tumour-bearing mice

    Tumour hypoxia is linked to treatment resistance. Positron emission tomography (PET) using hypoxia tracers such as fluoroazomycin arabinoside (FAZA) may allow identification of patients with hypoxic tumours and the monitoring of the efficacy of hypoxia-targeting treatment. Since hypoxia PET is characterized by poor image contrast, and tumour hypoxia undergoes spontaneous changes and is affected by therapy, it remains unclear to what extent PET scans are reproducible. Tumour-bearing mice are valuable in the validation of hypoxia PET, but identification of a reliable reference tissue value (blood sample or image-derived muscle value) for repeated scans may be difficult due to the small size of the animal or absence of anatomical information (pure PET). Here tumour hypoxia was monitored over time using repeated PET scans in individual tumour-bearing mice before and during fractionated radiotherapy. Mice bearing human SiHa cervix tumour xenografts underwent a PET scan 3 h following injection of FAZA on two consecutive days before initiation of treatment (baseline) and again following irradiation with four and ten fractions of 2.5 Gy. On the last scan day, mice were given an intraperitoneal injection of pimonidazole (hypoxia marker), tumours were collected and the intratumoral distribution of FAZA (autoradiography) and hypoxia (pimonidazole immunohistology) were determined in cryosections. Tissue section analysis revealed that the intratumoral distribution of FAZA was strongly correlated with the regional density of hypoxic (pimonidazole-positive) cells, even when necrosis was present, suggesting that FAZA PET provides a reliable measure of tumour hypoxia at the time of the scan. PET-based quantification of tumour tracer uptake relative to injected dose showed excellent reproducibility at baseline, whereas normalization using an image-derived nonhypoxic reference tissue (muscle) proved highly unreliable since a valid and reliable reference value could not be determined

  14. Standard-Fractionated Radiotherapy for Optic Nerve Sheath Meningioma: Visual Outcome Is Predicted by Mean Eye Dose

    Abouaf, Lucie [Neuro-Ophthalmology Unit, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); Girard, Nicolas [Radiotherapy-Oncology Department, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon (France); Claude Bernard University, Lyon (France); Lefort, Thibaud [Neuro-Radiology Department, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); D' hombres, Anne [Claude Bernard University, Lyon (France); Tilikete, Caroline; Vighetto, Alain [Neuro-Ophthalmology Unit, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); Claude Bernard University, Lyon (France); Mornex, Francoise, E-mail: francoise.mornex@chu-lyon.fr [Claude Bernard University, Lyon (France)

    2012-03-01

    Purpose: Radiotherapy has shown its efficacy in controlling optic nerve sheath meningiomas (ONSM) tumor growth while allowing visual acuity to improve or stabilize. However, radiation-induced toxicity may ultimately jeopardize the functional benefit. The purpose of this study was to identify predictive factors of poor visual outcome in patients receiving radiotherapy for ONSM. Methods and Materials: We conducted an extensive analysis of 10 patients with ONSM with regard to clinical, radiologic, and dosimetric aspects. All patients were treated with conformal radiotherapy and subsequently underwent biannual neuroophthalmologic and imaging assessments. Pretreatment and posttreatment values of visual acuity and visual field were compared with Wilcoxon's signed rank test. Results: Visual acuity values significantly improved after radiotherapy. After a median follow-up time of 51 months, 6 patients had improved visual acuity, 4 patients had improved visual field, 1 patient was in stable condition, and 1 patient had deteriorated visual acuity and visual field. Tumor control rate was 100% at magnetic resonance imaging assessment. Visual acuity deterioration after radiotherapy was related to radiation-induced retinopathy in 2 patients and radiation-induced mature cataract in 1 patient. Study of radiotherapy parameters showed that the mean eye dose was significantly higher in those 3 patients who had deteriorated vision. Conclusions: Our study confirms that radiotherapy is efficient in treating ONSM. Long-term visual outcome may be compromised by radiation-induced side effects. Mean eye dose has to be considered as a limiting constraint in treatment planning.

  15. Standard-Fractionated Radiotherapy for Optic Nerve Sheath Meningioma: Visual Outcome Is Predicted by Mean Eye Dose

    Purpose: Radiotherapy has shown its efficacy in controlling optic nerve sheath meningiomas (ONSM) tumor growth while allowing visual acuity to improve or stabilize. However, radiation-induced toxicity may ultimately jeopardize the functional benefit. The purpose of this study was to identify predictive factors of poor visual outcome in patients receiving radiotherapy for ONSM. Methods and Materials: We conducted an extensive analysis of 10 patients with ONSM with regard to clinical, radiologic, and dosimetric aspects. All patients were treated with conformal radiotherapy and subsequently underwent biannual neuroophthalmologic and imaging assessments. Pretreatment and posttreatment values of visual acuity and visual field were compared with Wilcoxon’s signed rank test. Results: Visual acuity values significantly improved after radiotherapy. After a median follow-up time of 51 months, 6 patients had improved visual acuity, 4 patients had improved visual field, 1 patient was in stable condition, and 1 patient had deteriorated visual acuity and visual field. Tumor control rate was 100% at magnetic resonance imaging assessment. Visual acuity deterioration after radiotherapy was related to radiation-induced retinopathy in 2 patients and radiation-induced mature cataract in 1 patient. Study of radiotherapy parameters showed that the mean eye dose was significantly higher in those 3 patients who had deteriorated vision. Conclusions: Our study confirms that radiotherapy is efficient in treating ONSM. Long-term visual outcome may be compromised by radiation-induced side effects. Mean eye dose has to be considered as a limiting constraint in treatment planning.

  16. Accelerated hyperfractionated radiotherapy combined with induction and concomitant chemotherapy for inoperable non-small-cell lung cancer. Impact of total treatment time

    Tumour cell proliferation during conventionally fractionated radiotherapy (RT) can negatively influence the treatment outcome in patients with unresectable non-small-cell lung cancer (NSCLC). Accelerated and hyperfractionated RT may therefore have an advantage over conventional RT. Moreover, earlier studies have suggested improved survival with addition of cisplatin-based chemotherapy (CT). We present here the results of combined treatment with induction and concomitant CT and accelerated hyperfractionated RT in a retrospective series of patients with advanced NSCLS. Between August 1990 and August 1995, 90 consecutive patients, aged 42-77 years (median 63 years), with locally advanced unresectable or medically inoperable NSCLC and good performance status were referred for treatment: stage: I 23%, IIIa 37%, IIIb 40%. Patient histologies included: squamous cell carcinoma 52%, adenocarcinoma 34% and large cell carcinoma 13%. The treatment consisted of two courses of CT (cisplatin 100 mg/m2 day 1 and etoposide 100 mg/m2 day 1-3 i.v.), the second course given concomitantly with RT. The total RT dose was 61.2-64.6 Gy, with two daily fractions of 1.7 Gy. A one-week interval was introduced after 40.8 Gy to reduce acute toxicity, making the total treatment time 4.5 weeks. Concerning toxicity, 33 patients had febrile neutropenia, 10 patients suffered from grade III oesophagitis and 7 patients had grade III pneumonitis. There were two possible treatment-related deaths, one due to myocardial infarction and the other due to a pneumocystis carinii infection. The 1-, 2- and 3-year overall survival rates were 72%, 46% and 34%, respectively; median survival was 21.3 months. Fifty-nine patients had progressive disease: 21 failed locoregionally, 29 had distant metastases and 9 patients had a combination of these. Pretreatment weight loss was the only prognostic factor found, except for stage. However, the results for stage IIIb were no different from those for stage IIIa. We conclude

  17. GPU-accelerated automatic identification of robust beam setups for proton and carbon-ion radiotherapy

    We demonstrate acceleration on graphic processing units (GPU) of automatic identification of robust particle therapy beam setups, minimizing negative dosimetric effects of Bragg peak displacement caused by treatment-time patient positioning errors. Our particle therapy research toolkit, RobuR, was extended with OpenCL support and used to implement calculation on GPU of the Port Homogeneity Index, a metric scoring irradiation port robustness through analysis of tissue density patterns prior to dose optimization and computation. Results were benchmarked against an independent native CPU implementation. Numerical results were in agreement between the GPU implementation and native CPU implementation. For 10 skull base cases, the GPU-accelerated implementation was employed to select beam setups for proton and carbon ion treatment plans, which proved to be dosimetrically robust, when recomputed in presence of various simulated positioning errors. From the point of view of performance, average running time on the GPU decreased by at least one order of magnitude compared to the CPU, rendering the GPU-accelerated analysis a feasible step in a clinical treatment planning interactive session. In conclusion, selection of robust particle therapy beam setups can be effectively accelerated on a GPU and become an unintrusive part of the particle therapy treatment planning workflow. Additionally, the speed gain opens new usage scenarios, like interactive analysis manipulation (e.g. constraining of some setup) and re-execution. Finally, through OpenCL portable parallelism, the new implementation is suitable also for CPU-only use, taking advantage of multiple cores, and can potentially exploit types of accelerators other than GPUs.

  18. Intra-fraction prostate displacement in radiotherapy estimated from pre- and post-treatment imaging of patients with implanted fiducial markers

    Purpose: To determine intra-fraction displacement of the prostate gland from imaging pre- and post-radiotherapy delivery of prostate cancer patients with three implanted fiducial markers. Methods and materials: Data were collected from 184 patients who had two orthogonal X-rays pre- and post-delivery on at least 20 occasions using a Varian On Board kV Imaging system. A total of 5778 image pairs covering time intervals between 3 and 30 min between pre- and post-imaging were evaluated for intra-fraction prostate displacement. Results: The mean three dimensional vector shift between images was 1.7 mm ranging from 0 to 25 mm. No preferential direction of displacement was found; however, there was an increase of prostate displacement with time between images. There was a large variation in typical shifts between patients (range 1 ± 1 to 6 ± 2 mm) with no apparent trends throughout the treatment course. Images acquired in the first five fractions of treatment could be used to predict displacement patterns for individual patients. Conclusion: Intra-fraction motion of the prostate gland appears to be a limiting factor when considering margins for radiotherapy. Given the variation between patients, a uniform set of margins for all patients may not be satisfactory when high target doses are to be delivered.

  19. Natural history of intracranial meningioma after radiotherapy

    The author examined the natural history of intracranial meningioma after radiotherapy using CT or MR imaging. Twenty patients with intracranial meningioma received radiotherapy from a high-energy linear accelerator (4-10 MV X rays) from 1980 to 1996. The total doses were 50 Gy to the tumor bed in single doses of 2 Gy in 5 weekly fractions. Meningiomas in 10 of 20 patients were reduced within 1 to 38 months after radiotherapy, the average being 11 months. The tumors were controlled for a median of 60 months after radiotherapy (range 19-126 months). Four other patients have shown no change in tumor size after radiotherapy. The tumors were controlled for a median of 70 months after radiotherapy (range 37-127 months). The other six patients have shown tumor growth within 3 to 25 months after radiotherapy, after which the tumors stopped growing for a median of 71 months (range 2-181 months). Neither tumor size nor histological type was related to response. The growth of tumors was controlled by radiotherapy for a median duration of 43 months in the meningothelial type, 52 months in the fibroblastic type, and 61 months in the transitional type. The median duration for all benign tumors was 52 months. A moderate correlation was noted between tumor response and functional outcome after radiotherapy in 9 patients with neurological deficits. The natural histories of intracranial meningiomas after radiotherapy were grouped into three categories. Some tumors showed no change in size over a long period. This was a characteristic response after radiotherapy that differed from that of other brain tumors. The results of this study provide important information for the follow-up of intracranial meningiomas after radiotherapy. (author)

  20. Germline glutathione S-transferase variants in breast cancer: Relation to diagnosis and cutaneous long-term adverse effects after two fractionation patterns of radiotherapy

    Purpose: To explore whether certain glutathione S-transferase (GST) polymorphisms are associated with an increased risk of breast cancer or the level of radiation-induced adverse effects after two fractionation patterns of adjuvant radiotherapy. Methods and Materials: The prevalence of germline polymorphic variants in GSTM1, GSTP1, and GSTT1 was determined in 272 breast cancer patients and compared with that in a control group of 270 women from the general population with no known history of breast cancer. The genetic variants were determined using multiplex polymerase chain reaction followed by restriction enzyme fragment analysis. In 253 of the patients surveyed for radiotherapy-induced side effects after a median observation time of 13.7 years (range, 7-22.8 years), the genotypes were related to the long-term effects observed after two fractionation patterns (treatment A, 4.3 Gy in 10 fractions for 156 patients; and treatment B, 2.5 Gy in 20 fractions for 97; both administered within a 5-week period). Results: None of the GST polymorphisms conferred an increased risk of breast cancer, either alone or in combination. Compared with treatment B, treatment A was followed by an increased level of moderate to severe radiation-induced side effects for all the endpoints studied (i.e., degree of telangiectasia, subcutaneous fibrosis and atrophy, lung fibrosis, costal fractures, and pleural thickening; p <0.001 for all endpoints). A significant association was found between the level of pleural thickening and the GSTP1 Ile105Val variant. Conclusion: The results of this study have illustrated the impact of hypofractionation on the level of adverse effects and indicated that the specific alleles of GSTP1, M1, and T1 studied here may be significant in determining the level of adverse effects after radiotherapy

  1. Treatment fractionation for stereotactic radiotherapy of lung tumours: a modelling study of the influence of chronic and acute hypoxia on tumour control probability

    Stereotactic body radiotherapy (SBRT) for non-small-cell lung cancer (NSCLC) has led to promising local control and overall survival for fractionation schemes with increasingly high fractional doses. A point has however been reached where the number of fractions used might be too low to allow efficient local inter-fraction reoxygenation of the hypoxic cells residing in the tumour. It was therefore the purpose of this study to investigate the impact of hypoxia and extreme hypofractionation on the tumour control probability (TCP) from SBRT. A three-dimensional model of tumour oxygenation able to simulate oxygenation changes on the microscale was used. The TCP was determined for clinically relevant SBRT fractionation schedules of 1, 3 and 5 fractions assuming either static tumour oxygenation or that the oxygenation changes locally between fractions due to fast reoxygenation of acute hypoxia without an overall reduction in chronic hypoxia. For the schedules applying three or five fractions the doses required to achieve satisfying levels of TCP were considerably lower when local oxygenation changes were assumed compared to the case of static oxygenation; a decrease in D50 of 17.7 Gy was observed for a five-fractions schedule applied to a 20% hypoxic tumour when fast reoxygenation was modelled. Assuming local oxygenation changes, the total doses required for a tumor control probability of 50% were of similar size for one, three and five fractions. Although attractive from a practical point of view, extreme hypofractionation using just one single fraction may result in impaired local control of hypoxic tumours, as it eliminates the possibility for any kind of reoxygenation

  2. IAEA-HypoX. A randomized multicenter study of the hypoxic radiosensitizer nimorazole concomitant with accelerated radiotherapy in head and neck squamous cell carcinoma

    Purpose: To test the hypothesis that radiotherapy (RT) of head and neck squamous cell carcinoma (HNSCC) can be improved by hypoxic modification using nimorazole (NIM) in association with accelerated fractionation. Materials and methods: The protocol was activated in March 2012 as an international multicenter randomized trial in patients with HNSCC. Tumors were treated to a dose of 66–70 Gy, 33–35 fractions, 6 fractions per week. NIM was administered in a dose of 1.2 g per m2, 90 min before the first daily RT fraction. The primary endpoint was loco-regional failure. The trial was closed prematurely by June 2014 due to poor recruitment. An associated quality assurance program was performed to ensure the consistency of RT with the protocol guidelines. Results: The trial was dimensioned to include 600 patients in 3 years, but only 104 patients were randomized between March 2012 and May 2014 due to the inability to involve three major centers and the insufficient recruitment rate from the other participating centers. Twenty patients from two centers had to be excluded from the analysis due to the unavailability of the follow-up data. Among the remaining 84 patients, 82 patients were evaluable (39 and 43 patients in the RT + NIM and the RT-alone arms, respectively). The treatment compliance was good with only six patients not completing the full planned RT course, and 31 patients (79%) out of 39 allocated for NIM, achieving at least 90% of the prescribed drug dose. At the time of evaluation, 40 patients had failed to achieve persistent loco-regional tumor control, and a total of 45 patients had died. The use of NIM improved the loco-regional tumor control with an 18 month post-randomization cumulative failure rate of 33% versus 51% in the control arm, yielding a risk difference of 18% (CI −3% to 39%; P = 0.10). The corresponding values for overall death was 43% versus 62%, yielding a risk difference of 19% (CI −3% to 42%; P = 0.10). Sixteen patients, out of 55

  3. Determination of radiation levels by neutrons in an accelerator for radiotherapy

    It was determined the radiation levels by neutrons due to photonuclear reactions (γ, n) which occur in the target, levelling filter, collimators and the small pillow blinding of a medical accelerator Varian Clinac 2100C of 18 MeV, using thermoluminescent dosemeters UD-802AS and US-809AS. The experimental values were presented for the patient level, inside and outside of the radiation field, as well as for the small pillow. (Author)

  4. Accelerated partial breast irradiation using 3D conformal radiotherapy: initial clinical experience

    Gatti, M.; Madeddu, A.; Malinverni, G.; Delmastro, E.; Bona, C.; Gabriele, P. [IRCC-Radiotherapy, Candiolo, TO (Italy); Baiotto, B.; Stasi, M. [IRCC-Medical Physics, Candiolo, TO (Italy); Ponzone, R.; Siatis, D. [IRCC-Surgery, Candiolo, TO (Italy)

    2006-11-15

    Accelerated partial breast irradiation using 3D-C.R.T. is technically sophisticate but feasible and acute toxicity to date has been minimal. A C.T.V.-to-P.T.V. margin of 10 mm seems to provide coverage for analyzed patients. However, more patients and additional studies will be needed to validate the accuracy of this margin, and longer follow-up will be needed to assess acute and chronic toxicity, tumor control, and cosmetic results. (author)

  5. Debate about breast cancer: 'Cons: Intraoperative radiotherapy'; Debats autour du cancer du sein: 'contre' la radiotherapie peroperatoire

    Bourgier, C.; Heymann, S.; Verstraet, R.; Biron, B.; Marsiglia, H. [Departement de radiotherapie, institut Gustave-Roussy, 114, rue edouard-Vaillant, 94800 Villejuif (France)

    2011-10-15

    Early breast cancer incidence increases owing to mammography screening. Hypo-fractionated radiotherapy is more and more proposed in women with low local relapse risk breast cancer, especially accelerated partial breast irradiation. Various irradiation modalities have been reported: brachytherapy, intraoperative irradiation, 3D-conformal accelerated partial breast irradiation. We describe limitations of intraoperative irradiation and the advantages of alternative techniques. (authors)

  6. Split course multiple daily fractionated radiotherapy schedule combined with misonidazole for the management of grade III and IV gliomas: a pilot feasibility study of the radiotherapy group of the EORTC

    The effect of a fractionated radiotherapy on tissue is not only determined by the total dose; but also by the dose per fraction and the overall time of treatment. Recent experimental data have demonstrated that with the overall treatment time of 6 or 7 weeks, as is usually the case in the clinical practice, the late tolerance of the central nervous system (CNS) is only determined by the fraction size. Based on these premises a totally new fractionation schedule for the treatment of malignant gliomas was developed. The interval between irradiation is reduced to 4 hr, which makes it practical and possible to give 3 fractions a day. Thus, 15 fractions of 2 Gy can be given in 5 days; this scheme can be repeated after a rest period of 2 weeks. In this way, a dose of 60 Gy can be delivered in an overall treatment time of 4 weeks. As the total number of treatment days is reduced this schedule reduces the burden on the patient, and renders a more efficient combination with misonidazole possible. A total of 122 patients have been treated according to this schedule. The acute tolerance has been found to be very good. Only 18% of the patients experienced transient severe side effects, such as nausea, vomiting, somnolence and headache. Thus, it has been proven that this treatment schedule reduces the burden on the patients. The median survival time of patients treated after tumor resection is over a year

  7. Report on a randomized trial comparing two forms of immobilization of the head for fractionated stereotactic radiotherapy

    Bednarz, Greg; Machtay, Mitchell; Werner-Wasik, Maria; Downes, Beverly; Bogner, Joachim; Hyslop, Terry; Galvin, James; Evans, James; Curran, Walter Jr.; Andrews, David [Department of Radiation Oncology, Kimmel Cancer Center of the Jefferson Medical College, Philadelphia, Pennsylvania 19107 (United States) and Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15232 (United States); Department of Radiation Oncology, Kimmel Cancer Center of the Jefferson Medical College, Philadelphia, Pennsylvania 19107 (United States); Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Department of Radiotherapy and Radiobiology, Medical University of Vienna, 1010 Vienna (Austria); Department of Biostatistics, Kimmel Cancer Center of the Jefferson Medical College, Philadelphia, Pennsylvania 19107 (United States); Department of Radiation Oncology, Kimmel Cancer Center of the Jefferson Medical College, Philadelphia, Pennsylvania 19107 (United States); Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Department of Radiation Oncology, Kimmel Cancer Center of the Jefferson Medical College, Philadelphia, Pennsylvania 19107 (United States) and Department of Radiation Oncology, Emory University, Atlanta, Georgia 30322 (United States); Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States)

    2009-01-15

    Fractionated stereotactic radiotherapy (SRT) requires accurate and reproducible immobilization of the patient's head. This randomized study compared the efficacy of two commonly used forms of immobilization used for SRT. Two routinely used methods of immobilization, which differ in their approach to reproduce the head position from day to day, are the Gill-Thomas-Cosman (GTC) frame and the BrainLab thermoplastic mask. The GTC frame fixates on the patient's upper dentition and thus is in direct mechanical contact with the cranium. The BrainLab mask is a two-part masking system custom fitted to the front and back of the patient's head. After patients signed an IRB-approved informed consent form, eligible patients were randomized to either GTC frame or mask for their course of SRT. Patients were treated as per standard procedure; however, prior to each treatment a set of digital kilovolt images (ExacTrac, BrainLabAB, Germany) was taken. These images were fused with reference digitally reconstructed radiographs obtained from treatment planning CT to yield lateral, longitudinal, and vertical deviations of isocenter and head rotations about respective axes. The primary end point of the study was to compare the two systems with respect to mean and standard deviations using the distance to isocenter measure. A total of 84 patients were enrolled (69 patients evaluable with detailed positioning data). A mixed-effect linear regression and two-tiled t test were used to compare the distance measure for both the systems. There was a statistically significant (p<0.001) difference between mean distances for these systems, suggesting that the GTC frame was more accurate. The mean 3D displacement and standard deviations were 3.17+1.95 mm for mask and 2.00+1.04 mm for frame. Both immobilization techniques were highly effective, but the GTC frame was more accurate. To optimize the accuracy of SRT, daily kilovolt image guidance is recommended with either immobilization

  8. Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields

    Mutyala Subhakar

    2008-11-01

    Full Text Available Abstract Purpose To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite™ applicator and compare to those produced by whole breast external beam radiotherapy (WBRT. Materials and methods Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10 and the dose received by 20 cc of the structure (D20, were calculated as well as the maximum and mean doses received. Results Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925–1380 cc. Cardiac volumes ranged from 337–551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction. Conclusion This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets. Trial registration Dana Farber Trial Registry number 03-179

  9. Accelerated partial breast irradiation with external beam three-dimensional conformal radiotherapy. Five-year results of a prospective phase II clinical study

    The aim of this study was to report the 5-year results of accelerated partial breast irradiation (APBI) using external beam three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2011, 44 patients with low-risk, stage I-II breast cancer underwent breast-conserving surgery. Postoperative APBI was given by means of 3D-CRT using three to five non-coplanar fields. The total dose of APBI was 36.9 Gy (nine fractions of 4.1 Gy b.i.d.). The mean follow-up time was 58.2 months for surviving patients. Survival results, side effects, and cosmetic results were assessed. One (2.3 %) local recurrence was observed, for a 5-year actuarial rate of 3.7 %. Neither regional nor distant failure was observed. Two patients died of internal disease. The 5-year disease-free, cancer-specific, and overall survival rates were 96.3, 100, and 95.1 %, respectively. Acute side effects included grade 1 (G1) erythema in 75 %, G1 parenchymal induration in 46 %, and G1 pain in 46 % of patients. No G2 or higher acute side effect occurred. Late side effects included G1, G2, and G3 fibrosis in 44, 7, and 2 % of patients, respectively, G1 skin pigmentation in 12 %, and G1 pain in 2 %. Asymptomatic fat necrosis occurred in 14 %. Cosmetic results were rated excellent or good in 86 % of cases by the patients themselves and 84 % by the physicians. The 5-year local tumor control, toxicity profile, and cosmetic results of APBI delivered with external beam 3D-CRT are encouraging and comparable to other APBI series. (orig.)

  10. Long-term results of low dose daily cisplatin chemotherapy used concurrently with modestly accelerated radiotherapy in locally advanced squamous cell carcinomas of the head neck cancer region

    Pramod Kumar Gupta

    2014-01-01

    Full Text Available Introduction: Concurrent single agent cisplatin (CDDP with radiotherapy (RT improves outcomes in locally advanced squamous cell carcinomas of the head neck (LA-SCCHN. CDDP at 100 mg/m 2 at 3 weekly intervals raise compliance, hospitalization, and supportive care issues. Low dose daily CDDP was delivered with RT to evaluate its compliance, long-term safety and efficacy. Patients and Methods: During the period of month between November 2005 and May 2007, 52 patients of stage III/IV LA-SCCHN were given with conventional RT in a phased manner (dose-70 Gy/35 fractions/6 weeks along with daily CDDP (6 mg/m 2 ; capped 10 mg-30 cycles over 6 weeks. No hospitalization or antiemetic cover was planned. Compliance, acute and late toxicity were recorded as per Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer grading system and survival outcomes were evaluated. Results : The median follow-up was 63 months. 43 (83% cases complied with RT schedule and >28 cycles of CDDP was administered in 38 (73% cases. Confluent mucositis was seen in 65%, Grade III/IV dysphagia in 67%; 77% required enteral feed and hospitalization in 15%. There were four treatment related deaths. At 5 years, the loco-regional control was 25% (median-11 months and the overall survival was 31% (median-11 months. The 5 years actuarial rates of late Grade III/IV toxicity was 24%. Late swallowing difficulty/aspiration were seen in 17%; xerostomia-40%; ototoxicity-6%; nephrotoxicity-4%; and no second malignancy. Conclusion: Low dose cisplatin with moderately accelerated RT schedule appears feasible and logistically suitable "out-patient" option without increasing long-term toxicity in LA-SCCHN cancer region.

  11. Can concomitant-boost accelerated radiotherapy be adopted as routine treatment for head-and-neck cancers? A 10-year single-institution experience

    Allal, Abdelkarim Said; Taussky, Daniel; Mach, Nicolas; Becker, Minerva; Bieri, Sabine; Dulguerov, Pavel

    2004-01-01

    Accelerated schedules are effective in overcoming repopulation during radiotherapy (RT) for head-and-neck cancers, but their feasibility is compromised by increased toxicity. The therapeutic ratio may be particularly favorable for 5-week regimens. This study reports the 10-year experience of a single institution in the routine use of concomitant boost RT as standard radical treatment in all but the most favorable stage patients.

  12. Accelerated partial breast irradiation with external beam three-dimensional conformal radiotherapy. Five-year results of a prospective phase II clinical study

    Mozsa, Emoeke [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Landesklinikum Wiener Neustadt, Department of Radiooncology and Radiotherapy, Wiener Neustadt (Austria); Meszaros, Norbert; Major, Tibor; Froehlich, Georgina; Stelczer, Gabor; Fodor, Janos; Polgar, Csaba [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Sulyok, Zoltan [National Institute of Oncology, Centre of Surgery, Budapest (Hungary)

    2014-05-15

    The aim of this study was to report the 5-year results of accelerated partial breast irradiation (APBI) using external beam three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2011, 44 patients with low-risk, stage I-II breast cancer underwent breast-conserving surgery. Postoperative APBI was given by means of 3D-CRT using three to five non-coplanar fields. The total dose of APBI was 36.9 Gy (nine fractions of 4.1 Gy b.i.d.). The mean follow-up time was 58.2 months for surviving patients. Survival results, side effects, and cosmetic results were assessed. One (2.3 %) local recurrence was observed, for a 5-year actuarial rate of 3.7 %. Neither regional nor distant failure was observed. Two patients died of internal disease. The 5-year disease-free, cancer-specific, and overall survival rates were 96.3, 100, and 95.1 %, respectively. Acute side effects included grade 1 (G1) erythema in 75 %, G1 parenchymal induration in 46 %, and G1 pain in 46 % of patients. No G2 or higher acute side effect occurred. Late side effects included G1, G2, and G3 fibrosis in 44, 7, and 2 % of patients, respectively, G1 skin pigmentation in 12 %, and G1 pain in 2 %. Asymptomatic fat necrosis occurred in 14 %. Cosmetic results were rated excellent or good in 86 % of cases by the patients themselves and 84 % by the physicians. The 5-year local tumor control, toxicity profile, and cosmetic results of APBI delivered with external beam 3D-CRT are encouraging and comparable to other APBI series. (orig.) [German] Evaluation der 5-Jahres-Ergebnisse bezueglich Ueberleben, Tumorkontrolle, Nebenwirkungen und Kosmetik nach Teilbrustbestrahlung (APBI) mittels 3-D-konformaler, akzelerierter Radiotherapie (3D-CRT). Zwischen 2006 und 2011 wurden 44 Patienten mit Brustkrebs im Stadium I-II und niedrigem Risikoprofil brusterhaltend operiert. Die adjuvante, 3-D-konformale APBI wurde mittels 3-5 nonkoplanarer Feldern durchgefuehrt. Die Gesamtdosis betrug 36,9 Gy bei 9 -mal 4,1 Gy b.i.d.. Nach

  13. Intensity-modulated radiotherapy with simultaneous modulated accelerated boost technique and chemotherapy in patients with nasopharyngeal carcinoma

    To present our experience of intensity-modulated radiotherapy (IMRT) with simultaneous modulated accelerated radiotherapy (SMART) boost technique in patients with nasopharyngeal carcinoma (NPC). Sixty eight patients of NPC were treated between April 2006 and December 2011 including 45 males and 23 females with mean age of 46 (range 15–78). Stage distribution was; stage I 3, stage II 7, stage III 26 and stage IV 32. Among 45 (66.2%) evaluated patients for presence of Epstein-Barr virus (EBV), 40 (88.8%) were positive for EBV. Median radiation doses delivered to gross tumor volume (GTV) and positive neck nodes were 66–70 Gy, 63 Gy to clinical target volume (CTV) and 50.4 Gy to clinically negative neck. In addition 56 (82.4%) patients with bulky tumors (T4/N2+) received neoadjuvant chemotherapy 2–3 cycles (Cisplatin/Docetaxel or Cisplatin/Epirubicin or Cisplatin/5 Flourouracil). Concurrent chemotherapy with radiation was weekly Cisplatin 40 mg/m2 (40 patients) or Cisplatin 100 mg/m2 (28 patients). With a median follow up of 20 months (range 3–43), one patient developed local recurrence, two experienced regional recurrences and distant failure was seen in 3 patients. Estimated 3 year disease free survival (DFS) was 94%. Three year DFS for patients with EBV was 100% as compared to 60% without EBV (p = 0.0009). Three year DFS for patients with undifferentiated histology was 98% as compared to 82% with other histologies (p = 0.02). Acute grade 3 toxicity was seen as 21 (30.9%) having G-III mucositis and 6 (8.8%) with G-III skin reactions. Late toxicity was minimal and loss of taste was seen in 3 patients (7.5%) at time of analysis. IMRT with SMART in combination with chemotherapy is feasible and effective in terms of both the clinical response and safety profile. EBV, histopathology and nodal involvement were found important prognostic factors for locoregional recurrence

  14. TLD Intercomparison in accelerators for radiotherapy in three Latin american countries; Intercomparacion TLD en aceleradores para radioterapia en tres paises latinoamericanos

    Gaona, E.; Azorin N, J.; Perez, M.A.; Picon, C.; Castellanos, E.; Plazas, M.C.; Murcia, G.; Archundia, L. [Depto. El Hombre y su Ambiente. Universidad Autonoma Metropolitana, Calz. Del Hueso 1100, 04960 Mexico D.F. (Mexico)

    1998-12-31

    In Radiotherapy one of the objectives is to establish and to give follow up to quality assurance programs which make sure that the doses administered to the patients with cancer are a high probability of a success in external radiation. Likewise, one of the present preoccupations of the United Nations Agencies as well as the International Atomic Energy Agency and the Pan-American Health Organization is the optimal employment of the radiations in the treatment of cancer patients since the administered dose in Radiotherapy suffers considerable variations by the lack of quality assurance programs. The use of Electron linear accelerators requires a program of quality assurance that includes expert personnel, equipment and adequate facilities. The more used methodology for the dosimetry calibration and characterization of X-ray beams and high energy electrons for radiotherapy use is using a ionization chamber dosemeter calibrated in a regional secondary standardization laboratory. However, to establish and give follow up to the quality assurance programs it is necessary the dosimetric intercomparison through TLD. In this study it was designed plastic phantoms with TLD crystals and it was made its characterization to realize an absorbed dose analysis in the crystals exposed at X-ray beams 6 MV and high energy electrons 10 and 12 MeV to standardize the dosimetric procedures and proceeding to realize an International Pilot intercomparison of absorbed doses in TLD crystals in three Latin American countries: Mexico, Peru and Colombia with the participation of accelerators of five different institutions. The found results show that the majority of the measured doses with TLD in the different accelerators were in the 0.95-1.05 range though it had two cases outside of this range. The use of the phantoms with TLD crystals shows that they are of excellent aid to make analysis of the doses administered to the patients and an intercomparison of results to standardize procedures at

  15. Clinical application of AcMAR (accelerated multiple-arc radiotherapy) for head and neck tumors. Results of a randomized, two-dose study in Kitami Red-Cross General Hospital

    ) in Group A suffered from mucosal ulceration, two of which resulted in patients' death. No late ulceration nor laryngeal edema was observed in Group B patients. Tumor control was impressive and promising; Nine out of 88 (followed >24 mo) ''in-field'' recurrence, only 3 ''outside'' failure (two of them were successfully ''salvaged'' by second Radiotherapy), and 8 distant failures. Three-year loco-regional control rate was 86.4%, and three-year cause-specific, disease-free survival was 77.3%. Our results strongly suggest that an improved tumor control could be obtained when the accelerated fractionation is combined with conformal radiotherapy. The dose limiting acute symptoms was volume-dependent (hence improved by AcMAR), but the late ulceration was not. The size of single fraction should, therefore, be kept with in a certain range. (author)

  16. On-Board Imaging Validation of Optically Guided Stereotactic Radiosurgery Positioning System for Conventionally Fractionated Radiotherapy for Paranasal Sinus and Skull Base Cancer

    Maxim, Peter G.; Loo, Billy W.; Murphy, James D.; Chu, Karen P.M.; Hsu, Annie [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Le, Quynh-Thu, E-mail: Qle@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)

    2011-11-15

    Purpose: To evaluate the positioning accuracy of an optical positioning system for stereotactic radiosurgery in a pilot experience of optically guided, conventionally fractionated, radiotherapy for paranasal sinus and skull base tumors. Methods and Materials: Before each daily radiotherapy session, the positioning of 28 patients was set up using an optical positioning system. After this initial setup, the patients underwent standard on-board imaging that included daily orthogonal kilovoltage images and weekly cone beam computed tomography scans. Daily translational shifts were made after comparing the on-board images with the treatment planning computed tomography scans. These daily translational shifts represented the daily positional error in the optical tracking system and were recorded during the treatment course. For 13 patients treated with smaller fields, a three-degree of freedom (3DOF) head positioner was used for more accurate setup. Results: The mean positional error for the optically guided system in patients with and without the 3DOF head positioner was 1.4 {+-} 1.1 mm and 3.9 {+-} 1.6 mm, respectively (p <.0001). The mean positional error drifted 0.11 mm/wk upward during the treatment course for patients using the 3DOF head positioner (p = .057). No positional drift was observed in the patients without the 3DOF head positioner. Conclusion: Our initial clinical experience with optically guided head-and-neck fractionated radiotherapy was promising and demonstrated clinical feasibility. The optically guided setup was especially useful when used in conjunction with the 3DOF head positioner and when it was recalibrated to the shifts using the weekly portal images.

  17. On-Board Imaging Validation of Optically Guided Stereotactic Radiosurgery Positioning System for Conventionally Fractionated Radiotherapy for Paranasal Sinus and Skull Base Cancer

    Purpose: To evaluate the positioning accuracy of an optical positioning system for stereotactic radiosurgery in a pilot experience of optically guided, conventionally fractionated, radiotherapy for paranasal sinus and skull base tumors. Methods and Materials: Before each daily radiotherapy session, the positioning of 28 patients was set up using an optical positioning system. After this initial setup, the patients underwent standard on-board imaging that included daily orthogonal kilovoltage images and weekly cone beam computed tomography scans. Daily translational shifts were made after comparing the on-board images with the treatment planning computed tomography scans. These daily translational shifts represented the daily positional error in the optical tracking system and were recorded during the treatment course. For 13 patients treated with smaller fields, a three-degree of freedom (3DOF) head positioner was used for more accurate setup. Results: The mean positional error for the optically guided system in patients with and without the 3DOF head positioner was 1.4 ± 1.1 mm and 3.9 ± 1.6 mm, respectively (p <.0001). The mean positional error drifted 0.11 mm/wk upward during the treatment course for patients using the 3DOF head positioner (p = .057). No positional drift was observed in the patients without the 3DOF head positioner. Conclusion: Our initial clinical experience with optically guided head-and-neck fractionated radiotherapy was promising and demonstrated clinical feasibility. The optically guided setup was especially useful when used in conjunction with the 3DOF head positioner and when it was recalibrated to the shifts using the weekly portal images.

  18. Development of re-locatable head frame system using hydraulic arms for fractionated stereotactic radiotherapy and CT evaluation of repositioning accuracy

    The purpose of this study was to develop a novel re-locatable head frame system consisting of a dental cast and hydraulic arms as an immobilization device for fractionated stereotactic radiotherapy and to evaluate the repositioning accuracy by measurement of landmark coordinates in repeated computed tomography (CT) examinations. The acrylic dental casts were customized for each patient. First the dental cast was attached to the upper jaw of the patient, then the dental cast was connected to a Leksell stereotactic frame, which was finally secured by two hydraulic arms. Since this system is compatible with the Leksell frame, stereotactic indicators could be used to obtain coordinates of anatomical landmarks of the head. Seven patients treated by fractionated stereotactic radiotherapy underwent repeated quality-assurance CTs during their treatment courses. We evaluated the coordinates of the short process of incus and the top of crista galli as reference points for evaluation of variation in a total of 26 repeat CT data sets, and then x, y, and z fluctuations relative to their positions in the treatment-planning CTs. The distances among the reference points of both processes of incus and the top of crista galli were calculated to evaluate the feasibility of the method. The distances were less than 0.5 mm on averages and less than 1 mm in the standard deviations. The respective fluctuations in the x, y and z directions were less than 1 mm in mean values and less than 2 mm in standard deviations. The fluctuations in distance were less than 2 mm on average and in standard deviations. The fluctuation of the center of three reference points was 0.7 mm on average and the rotation of the cranium was 1.0 degree in average. We concluded that our evaluation method is feasible and the reproducibility of the fixation system is acceptable for its routine use in stereotactic radiotherapy. (author)

  19. Targeted antisense radiotherapy and dose fractionation using a 177Lu-labeled anti-bcl-2 peptide nucleic acid-peptide conjugate

    Introduction: The overall goal of these studies was to test the hypothesis that simultaneous down-regulation of a tumor survival gene and delivery of internally emitted cytotoxic radiation will be more effective than either treatment modality alone. The objectives were to evaluate the therapeutic efficacy of a 177Lu-labeled anti-bcl-2-PNA-Tyr3-octreotate antisense conjugate in a mouse model bearing human non-Hodgkin’s lymphoma (NHL) tumor xenografts and to optimize targeted antisense radiotherapy by dose fractionation. Methods: In the initial therapy studies, tumor-bearing mice were given saline, nonradioactive DOTA-anti-bcl-2-PNA-Tyr3-octreotate, 177Lu-DOTA-Tyr3-octreotate, 177Lu-DOTA-PNA-peptide alone, or 177Lu-DOTA-PNA-peptide followed by a chase dose of nonradioactive PNA-peptide. The MTD of 177Lu-DOTA-anti-bcl-2-PNA-Tyr3-octreotate was then determined. Subsequently single dose MTD and four weekly fractionated doses were directly compared, followed by histopathologic evaluation. Results: Antisense radiotherapy using 4.44 MBq of the 177Lu-DOTA-PNA-peptide followed by nonradioactive PNA-peptide was significantly more effective than other low dose treatment regimens. A dose of 18.5 MBq of 177Lu-DOTA-PNA-peptide was determined to be the approximate maximum tolerated dose (MTD). The median times to progression to a 1 cm3 tumor volume were 32 and 49 days for single dose MTD and fractionated dose (4 × 4.63 MBq) groups, respectively. Histopathology revealed metastases in the single dose groups, but not in the dose fractionation group. Conclusions: Targeted antisense radiotherapy using 177Lu-DOTA-anti-bcl-2-PNA-Tyr3-octreotate and DOTA-PNA-peptide conjugate effectively inhibited tumor progression in a mouse model of NHL. Furthermore, a dose fractionation regimen had a significant advantage over a single high dose, in terms of tumor growth inhibition and prevention of metastasis. Advances in knowledge and implications for patient care: Down-regulating bcl-2, an anti

  20. Whole brain radiotherapy: Prognostic factors and results of a radiation boost delivered through a conventional linear accelerator

    Purpose: Assess prognostic factors for overall survival and the potential benefit of a boost in patients treated with whole brain radiation therapy (WBRT). Methods and materials: From 2002 to 2006, a retrospective analysis was made from 250 unselected consecutive patients with secondary brain metastases from lung cancer, breast cancer and melanoma. Eighteen patients received surgery and were excluded from analysis. Four potential prognostic factors have been studied: primary tumor type, gender, number of metastases and improvement of neurological symptoms after radiation therapy. A subgroup analysis was performed to determine whether an additional boost could potentially improve outcome in patients who presented with less than three metastases, performance status <2, and no surgical resection of their metastasis. Results: Average follow-up was 10.3 months. Median overall survival was 5.6 months and survival rates at 1 and 2 years were 22.7% and 10%, respectively. Age less than 65 (p < 0.01), neurological improvement after WBRT (p < 0.01), and presence of less than three metastases were significant factors for overall survival in multivariate analysis. When focusing on the selected subgroup (120 assessable patients), median overall survival was 4.0 months in patients with no radiation boost, versus 8.9 months in patients with radiation boost (p = 0.0024). Conclusions: Survival and prognostic factors were similar to those found in the literature. Boost delivered after WBRT by a conventional particle accelerator could provide a benefit in selected patients, especially for centers that do not have radiotherapy techniques in stereotactic conditions. This warrants further prospective assessment.

  1. [Long-term results and cause of failure analysis in larynx cancer patients irradiated conventionally and with accelerated fractionation schedules in 1995-1998].

    Szutkowski, Zbigniew; Kawecki, Andrzej; Jarząbski, Andrzej

    2014-01-01

    The clinical material consists of 217 patients with squamous cell carcinoma in supraglottic and glottic larynx in clinical stage T1-3N0M0 irradiated radically in Warsaw Oncology Centre in 1995-1998. All patients were treated with Co-60, according to two schedules of fractionation, with maintenance of the consistent therapeutic protocol. The same team of doctors worked on the treatment of patients and on the follow-up as well. The clinical material is a part of a three-phased clinical trial KBN 0295. In the course of observation, the progression of cancer was not observed in 157 patients, among whom, 66% were treated conventionally and 79% with accelerated fractionation method. 60 cases of loco-regional recurrences were noted, among which 55 were regional. The majority of failure cases was observed until the 30(th) of the month after the radiotherapy ended. In conventional fractionation treatment, recurrences in T1 were 8/31 (26%), in T2 22/59 (37%) and in T3 8/20 (40%). In patients treated with AF, recurrences were T1 5/39 (13%), T2 15/55 (27%) and T3 2/13 (15%) respectively. The percentage of primary site tumour recurrences for each localization and kind of treatment was analysed. In CF 28/78 (37%) of glottic tumour recurrences and 10/34 (29%) of supraglottic tumour, recurrences were observed. In AF, 12/71 (17%) and 10/36 (28%) were observed respectively. In 48 cases salvage surgery was used, and 12 patients were not qualified because of tumour massive progression or because they refused to have a surgery. Among 34 cases (16%) of the second primary tumour or distant methastases, 25 were observed with glottic cancer, among which 23 were observed in early stages, and 9 cases with supraglottic cancer, among which, 6 showed early stage of tumour. In only 3 cases out of all the patients, distant methastases were confirmed in histopatology examination. The main cause of failure in larynx cancer patients in stage T1 is that 3N0M0 are local recurrences. Second primary or

  2. IsoBED: a tool for automatic calculation of biologically equivalent fractionation schedules in radiotherapy using IMRT with a simultaneous integrated boost (SIB technique

    Benassi Marcello

    2011-05-01

    Full Text Available Abstract Background An advantage of the Intensity Modulated Radiotherapy (IMRT technique is the feasibility to deliver different therapeutic dose levels to PTVs in a single treatment session using the Simultaneous Integrated Boost (SIB technique. The paper aims to describe an automated tool to calculate the dose to be delivered with the SIB-IMRT technique in different anatomical regions that have the same Biological Equivalent Dose (BED, i.e. IsoBED, compared to the standard fractionation. Methods Based on the Linear Quadratic Model (LQM, we developed software that allows treatment schedules, biologically equivalent to standard fractionations, to be calculated. The main radiobiological parameters from literature are included in a database inside the software, which can be updated according to the clinical experience of each Institute. In particular, the BED to each target volume will be computed based on the alpha/beta ratio, total dose and the dose per fraction (generally 2 Gy for a standard fractionation. Then, after selecting the reference target, i.e. the PTV that controls the fractionation, a new total dose and dose per fraction providing the same isoBED will be calculated for each target volume. Results The IsoBED Software developed allows: 1 the calculation of new IsoBED treatment schedules derived from standard prescriptions and based on LQM, 2 the conversion of the dose-volume histograms (DVHs for each Target and OAR to a nominal standard dose at 2Gy per fraction in order to be shown together with the DV-constraints from literature, based on the LQM and radiobiological parameters, and 3 the calculation of Tumor Control Probability (TCP and Normal Tissue Complication Probability (NTCP curve versus the prescribed dose to the reference target.

  3. [Whole Brain Irradiation and Hypo-fractionation Radiotherapy for the Metastases in Non-small Cell Lung Cancer].

    Gu, Xingting; Zhao, Yaqin; Xu, Feng

    2016-04-20

    Up to 40% non-small cell lung cancer patients developed brain metastasis during progression. Multiple brain metastases are common in non-small cell lung cancer. The prognosis of brain metastasis is poor with median survival of less than 1 year. Radio therapy for brain metastases has gradually developed from whole brain radiotherapy (WBRT) to various radiation strategies. WBRT, surgery+WBRT, stereotactic radiotherapy+WBRT or WBRT with simultaneous integrated boost (SIB), etc. have better overall survival than those untreated patients. The damage of the cognitive function from WBRT has been realized recently, however, options of radiation strategies for long expected survival patients remain controversial. This paper will discuss different WBRT strategies and treatment side effects of non-small cell lung cancer with brain metastases. PMID:27118651

  4. Accelerated partial breast irradiation: Bi-fractionated 40 Gy in one week. A French pilot phase II study

    Purpose: Since 2009, accelerated partial breast irradiation (APBI) in North America has been allowed to be used for selected group of patients outside a clinical trial according to the ASTRO consensus statement. In France, accelerated partial breast irradiation is still considered investigational, several clinical trials have been conducted using either intraoperative (Montpellier) or MammositeR (Lille) or brachytherapy modality (PAC GERICO/FNCLCC). Here, we report the original dosimetric results of this technique. Patients and methods: Since October 2007, Institut Gustave-Roussy has initiated a phase II trial using 3D-conformal accelerated partial breast irradiation (40 Gy in 10 fractions BID in 1 week). Twenty-five patients with pT1N0 breast cancer were enrolled and were treated by two mini-tangent photons beams (6 MV) and an 'en face' electron beam (6-22 MeV). Results: The mean clinical target volume and planning target volume were respectively 15.1 cm3 (range: 5.2-28.7 cm3) and 117 cm3 (range: 52-185 cm3). The planning target volume coverage was adequate with at least a mean of 99% of the volume encompassed by the isodose 40 Gy. The mean dose to the planning target volume was 41.8 Gy (range: 41-42.4 Gy). Dose inhomogeneity did not exceed 5%. Mean doses to the ipsilateral lung and heart were 1.6 Gy (range: 1.0-2.3 Gy) and 1.2 Gy (range: 1.0-1.6 Gy), respectively. Conclusion: The 3D conformal accelerated partial breast irradiation using two mini-tangent and 'en face' electron beams using a total dose of 40 Gy in 10 fractions BID over 5 days achieves appropriate planning target volume coverage and offers significant normal-tissue sparing (heart, lung). Longer follow-up is needed to evaluate the tissue tolerance to this radiation dose. (authors)

  5. Quality assurance audit in an Australasian phase III trial of accelerated radiotherapy for head and neck cancer (TROG 91.01)

    The Trans-Tasman Radiation Oncology Group (TROG) initiated a randomized trial, testing accelerated (twice daily) radiotherapy against conventional radiotherapy for stage II and stage IV squamous cell carcinoma of the head and neck in 1991. In 1996, the Trial Management Committee arranged for a technical audit of 76 cases from 11 institutions, conducted by investigators from interstate institutions. A 10% unacceptable protocol violation rate was detected, which compares favourably with initial Radiation Therapy Oncology Group (RTOG) experience in the late 1970s. Infrastructural deficits with poor quality of documentation, incomplete retrieval of films and document return have been demonstrated in some cases. The Trans-Tasman Radiation Oncology Group is actively pursuing procedural and resourcing issues in order to redress this and is actively expanding its Quality Assurance (QA) Programme with an intercentre dosimetry study. Ultimately, comprehensive clinical and technical QA site visits are planned. Copyright (1999) Blackwell Science Pty Ltd

  6. Randomized multicenter follow-up trial on the effect of radiotherapy for plantar fasciitis (painful heels spur) depending on dose and fractionation – a study protocol

    An actual clinical trial showed the effect of low dose radiotherapy in painful heel spur (plantar fasciitis) with single doses of 1.0 Gy and total doses of 6.0 Gy applied twice weekly. Furthermore, a lot of animal experimental and in vitro data reveals the effect of lower single doses of 0.5 Gy which may be superior in order to ease pain and reduce inflammation in patients with painful heel spur. Our goal is therefore to transfer this experimentally found effect into a randomized multicenter trial. This was a controlled, prospective, two-arm phase III-multicenter trial. The standard arm consisted of single fractions of 1.0 Gy applied two times a week, for a total dose of 6.0 Gy (total therapy time: 3 weeks). The experimental arm consisted of single fractions of 0.5 Gy applied 3 times a week, for a total dose of 6.0 Gy (total therapy time: 4 weeks). Following a statistical power calculation, there were 120 patients for each investigation arm. The main inclusion criteria were: age > = 40 years, clinical and radiologically diagnosed painful heel spur (plantar fasciitis), and current symptoms for at least 6 months. The main exclusion criteria were: former local trauma, surgery or radiotherapy of the heel; pregnant or breastfeeding women; and a pre-existing severe psychiatric or psychosomatic disorder. After approving a written informed consent the patients are randomized by a statistician into one of the trial arms. After radiotherapy, the patients are seen after six weeks, after twelve weeks and then every twelve weeks up to 48 weeks. Additionally, they receive a questionnaire every six weeks after the follow-up examinations up to 48 weeks. The effect is measured using the visual analogue scale of pain (VAS), the calcaneodynia score according to Rowe and the SF-12 score. The primary endpoint is the pain relief three months after therapy. Patients of both therapy arms with an insufficient result are offered a second radiotherapy series applying the standard dose

  7. Comparison of long-term survival and toxicity of simultaneous integrated boost vs conventional fractionation with intensity-modulated radiotherapy for the treatment of nasopharyngeal carcinoma

    Tao HM

    2016-03-01

    Full Text Available Hengmin Tao,1,2 Yumei Wei,1 Wei Huang,1 Xiujuan Gai,1,2 Baosheng Li11Department of 6th Radiation Oncology, Shandong Cancer Hospital and Institute, 2School of Medicine and Life Sciences, Jinan University-Shandong Academy of Medical Sciences, Jinan, People’s Republic of ChinaAim: In recent years, the intensity-modulated radiotherapy with simultaneous integrated boost (IMRT-SIB and intensity-modulated radiotherapy with conventional fractionation (IMRT-CF have been involved in the treatment of nasopharyngeal carcinoma (NPC. However, the potential clinical effects and toxicities are still controversial.Methods: Here, 107 patients with biopsy-proven locally advanced NPC between March 2004 and January 2011 were enrolled in the retrospective study. Among them, 54 patients received IMRT-SIB, and 53 patients received IMRT-CF. Subsequently, overall survival (OS, 5-year progression-free survival (PFS, 5-year locoregional recurrence-free survival (LRFS, and relevant toxicities were analyzed.Results: In the present study, all patients completed the treatment, and the overall median follow-up time was 80 months (range: 8–126 months. The 5-year OS analysis revealed no significant difference between the IMRT-SIB and IMRT-CF groups (80.9% vs 80.5%, P=0.568. In addition, there were also no significant between-group differences in 5-year PFS (73.3% vs 74.4%, P=0.773 and 5-year LRFS (88.1% vs 90.8%, P=0.903. Notably, the dose to critical organs (spinal cord, brainstem, and parotid gland in patients treated by IMRT-CF was significantly lower than that in patients treated by IMRT-SIB (all P<0.05.Conclusion: Both IMRT-SIB and IMRT-CF techniques are effective in treating locally advanced NPC, with similar OS, PFS, and LRFS. However, IMRT-CF has more advantages than IMRT-SIB in protecting spinal cord, brainstem, and parotid gland from acute and late toxicities, such as xerostomia. Further prospective study is warranted to confirm our findings.Keywords: intensity

  8. Accelerated repopulation of mouse tongue epithelium during fractionated irradiations or following single doses

    Mouse tongue mucosa was established as an animal model to study repopulation after large single doses or during continuous irradiation. A top-up irradiation technique was used employing priming doses or fractionated treatment to the whole snout (300 kV X-rays) followed by local test doses (25 kV X-rays) to elicit denudation in a confined field of the inferior tongue surface. Clearcut quantal dose-response curves of ulcer incidence were obtained to all protocols; animal morbidity, i.e. body weight loss was minimal. Repopulation following priming doses of 10 and 13 Gy started with a delay of at least 3 days and then progressed rapidly to nearly restore original tissue tolerance by day 11. During continuous fractionation over 1 to 3 weeks with 5 fractions/week and doses per fraction of 2.5, 3 and 3.5 Gy, repopulation was small in week one but subsequently increased to fully compensate the weekly dose at all dose levels. Additional measurements of cell density during a 4 weeks course of 5 x 3 Gy or 5 x 4 Gy per week showed only moderate depletion to 67% of the control figures. The fact that rapid repopulation is achieved at relatively moderate damage levels should be taken into account when the timing of a treatment split is considered. (author). 18 refs.; 7 figs.; 1 tab

  9. Study of efficacy and toxicity of hypofractionated thoracic radiotherapy 17 gray in 2 fractions for palliation in advanced non-small-cell lung cancer

    Objective: To determine the efficacy and toxicity of hypofractionated thoracic radiotherapy 17 Gray (Gy) in 2 fractions for palliation in advanced non-small-cell lung carcinoma. Study design: A quasi-experimental study. Place and duration of study: Oncology department, Combined Military Hospital, Rawalpindi, from 4th July 2008 to 4th Nov 2009. Material and Methods: Fifty four patients with histologically and/or cytologically confirmed unresectable stages III and IV non small cell lung cancer, with performance status 2 or 3 and expected survival > 2 months were treated with megavoltage radiation therapy 17 Gy in 2 fractions one week apart, with symptoms due to intrathoracic disease (cough, dyspnea and hemoptysis) and toxicity due to radiation therapy (dysphagia secondary to esophagitis) assessed as per common toxicity criteria adverse event version 3.0 on day 0 before treatment and day 30 after start of treatment. Results: Grades of cough, hemoptysis and dyspnea showed significant improvement after treatment (p<0.001). A total of 42.68% patients showed an improvement in grade of cough (23 out of 54 patients), 85.7% of patients showed improvement in grade of hemoptysis (36 out of 42 patients) and 55.65% patients showed improvement in grade of dyspnea (30 out of 54 patients). Twenty two point two percent patients (12 out of 54) showed increase in grade of dysphagia. Although, there was a statistically significant increase in grade of dysphagia after treatment but it was limited to grade 1 and 2 only. Considering that no patient had grade 3 or 4 dysphagia, this toxicity was acceptable. Conclusion: Based on our results hypofractionated thoracic radiotherapy, 17 Gy in 2 fractions, is effective with acceptable toxicity in palliation in advanced non small cell lung cancer and is recommended as it will result in shorter duration of hospital stay and low hospital stay charges. (author)

  10. Searching for the optimal radiotherapy treatment time, dose and fractionation - the role of hypoxia and reoxygenation : A modelling study

    Lindblom, Emely

    2014-01-01

    The search for the optimal choice of treatment time, dose and fractionation regimen is one of the major challenges in radiation therapy. Several aspects of the radiation response of tumours and normal tissues give different indications of how the parameters defining a fractionation schedule should be altered relative to each other which often results in contradictory conclusions. For example, the increased sensitivity to fractionation in late-reacting as opposed to early-reacting tissues indi...

  11. Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54–56 Gy given in 9–7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size

    Radiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor. During 2003–2008, 41 patients with 42 lung tumors were treated with SBRT to 54–56 Gy in 9–7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study. Median follow-up time was 68 months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16–48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54 Gy were 47.7% and 12.9% (p = 0.0184), and for fraction size of 6, 7 and 8 Gy were 19.5%, 31.2% and 55.7% (p = 0.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10–55, age, sex, and planning target volume were not significantly different. The doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures

  12. Fractionated stereotactic radiotherapy of benign skull-base tumors: a dosimetric comparison of volumetric modulated arc therapy with Rapidarc® versus non-coplanar dynamic arcs

    Benign tumors of the skull base are a challenge when delivering radiotherapy. An appropriate choice of radiation technique may significantly improve the patient’s outcomes. Our study aimed to compare the dosimetric results of fractionated stereotactic radiotherapy between non-coplanar dynamic arcs and coplanar volumetric modulated arctherapy (Rapidarc®). Thirteen patients treated with Novalis TX® were analysed: six vestibular schwannomas, four pituitary adenomas and three meningioma. Two treatment plans were created for each case: dynamic arcs (4–5 non coplanar arcs) and Rapidarc® (2 coplanar arcs). All tumors were >3 cm and accessible to both techniques. Patients had a stereotactic facemask (Brainlab) and were daily repositioned by Exactrac®. GTV and CTV were contoured according to tumor type. A 1-mm margin was added to the CTV to obtain PTV. Radiation doses were 52.2–54 Gy, using 1.8 Gy per fraction. Treatment time was faster with Rapidarc®. The mean PTV V95 % was 98.8 for Rapidarc® and 95.9 % for DA (p = 0.09). Homogeneity index was better with Rapidarc®: 0.06 vs. 0.09 (p = 0.01). Higher conformity index values were obtained with Rapidarc®: 75.2 vs. 67.9 % (p = 0.04). The volume of healthy brain that received a high dose (V90 %) was 0.7 % using Rapidarc® vs. 1.4 % with dynamic arcs (p = 0.05). Rapidarc® and dynamic arcs gave, respectively, a mean D40 % of 10.5 vs. 18.1 Gy (p = 0.005) for the hippocampus and a Dmean of 25.4 vs. 35.3 Gy (p = 0.008) for the ipsilateral cochlea. Low-dose delivery with Rapidarc® and dynamic arcs were, respectively, 184 vs. 166 cm3 for V20 Gy (p = 0.14) and 1265 vs. 1056 cm3 for V5 Gy (p = 0.67). Fractionated stereotactic radiotherapy using Rapidarc® for large benign tumors of the skull base provided target volume coverage that was at least equal to that of dynamics arcs, with better conformity and homogeneity and faster treatment time. Rapidarc® also offered better sparing of the ipsilateral cochlea and hippocampus

  13. Retarding Sub- and Accelerating Super-Diffusion Governed by Distributed Order Fractional Diffusion Equations

    Chechkin, A. V.; Gorenflo, R.; I. M. Sokolov

    2002-01-01

    We propose diffusion-like equations with time and space fractional derivatives of the distributed order for the kinetic description of anomalous diffusion and relaxation phenomena, whose diffusion exponent varies with time and which, correspondingly, can not be viewed as self-affine random processes possessing a unique Hurst exponent. We prove the positivity of the solutions of the proposed equations and establish the relation to the Continuous Time Random Walk theory. We show that the distri...

  14. Fractionated and single-dose radiotherapy for heterotopic bone formation in patients with spinal cord injury. A phase-I/II study

    Background: Heterotopic ossification occur in about 20% of patients with spinal cord injury and may seriously compromise the rehabilitation process. Aim of the present study was to evaluate if radiotherapy administered early in the course of the disease prevents the manifestation of heterotopic ossification and if in patients whose bone formations have been resected recurrence can be avoided. Patients and Methods: 52 patients (44 males, eight females, median age 33 years) and 75 joints were irradiated between December 1989 and March 2000. 49 patients (70 joints, 65 hips, three knees, one shoulder, one elbow) were evaluable. Median follow-up was 11 months. In 58 joints radiotherapy was performed as a primary treatment in the inflammatory phase of soft tissue swelling that precedes manifestation of heterotopic ossifications. Twelve joints were treated after resection of manifest heterotopic bone, two patients had primary and postoperative irradiation in different joints. The dose was 10 Gy in single fractions of 2-2,5 Gy in 34 joints and 7.5-20 Gy in six joints. From July 1996 on, 30 joints received single-dose irradiation with 8 Gy. Results: 50/70 joints (71%) remained free from progression. This was the case for 47/65 (72%) hips, whereas in 18 hips (27%) the Brooker score increased for 1-2 grades and caused a moderate decrease of mobility in five joints. Out of the other five joints, two knees developed progression. No relevant side effects occurred. Conclusion: The present results suggest that radiotherapy is an effective local treatment option for spinal cord injured patients with heterotopic ossifications. (orig.)

  15. Tumor Shrinkage Assessed by Volumetric MRI in Long-Term Follow-Up After Fractionated Stereotactic Radiotherapy of Nonfunctioning Pituitary Adenoma

    Kopp, Christine, E-mail: Christine.Kopp@lrz.tu-muenchen.de [Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie, Klinikum rechts der Isar, Technische Universitaet Muenchen, Munich (Germany); Theodorou, Marilena; Poullos, Nektarios; Jacob, Vesna; Astner, Sabrina T.; Molls, Michael [Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie, Klinikum rechts der Isar, Technische Universitaet Muenchen, Munich (Germany); Grosu, Anca-Ligia [Klinik fuer Strahlenheilkunde, Universitaet Freiburg, Freiburg (Germany)

    2012-03-01

    Purpose: To evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent nonfunctioning pituitary adenomas (NFPAs). Methods and Materials: We assessed exact tumor volume shrinkage in 16 patients with NFPA after FSRT. All patients had previously undergone surgery. Gross tumor volume (GTV) was outlined on contrast-enhanced magnetic resonance imaging (MRI) before and median 63 months (range, 28-100 months) after FSRT. MRI was performed as an axial three-dimensional gradient echo T1-weighted sequence at 1.6-mm slice thickness without gap (3D MRI). Results: Mean tumor size of all 16 pituitary adenomas before treatment was 7.4 mL (3.3-18.9 mL). We found shrinkage of the treated pituitary adenoma in all patients. Within a median follow-up of 63 months (28-100 months) an absolute mean volume reduction of 3.8 mL (0.9-12.4 mL) was seen. The mean relative size reduction compared with the volume before radiotherapy was 51% (22%-95%). Shrinkage measured by 3D MRI was greater at longer time intervals after radiotherapy. A strong negative correlation between the initial tumor volume and the absolute volume reduction after FSRT was found. There was no correlation between tumor size reduction and patient age, sex, or number of previous surgeries. Conclusions: By using 3D MRI in all patients undergoing FSRT of an NFPA, tumor shrinkage is detected. Our data demonstrate that volumetric assessment based on 3D MRI adds additional information to routinely used radiological response measurements. After FSRT a mean relative size reduction of 51% can be expected within 5 years.

  16. Tumor Shrinkage Assessed by Volumetric MRI in Long-Term Follow-Up After Fractionated Stereotactic Radiotherapy of Nonfunctioning Pituitary Adenoma

    Purpose: To evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent nonfunctioning pituitary adenomas (NFPAs). Methods and Materials: We assessed exact tumor volume shrinkage in 16 patients with NFPA after FSRT. All patients had previously undergone surgery. Gross tumor volume (GTV) was outlined on contrast-enhanced magnetic resonance imaging (MRI) before and median 63 months (range, 28–100 months) after FSRT. MRI was performed as an axial three-dimensional gradient echo T1-weighted sequence at 1.6-mm slice thickness without gap (3D MRI). Results: Mean tumor size of all 16 pituitary adenomas before treatment was 7.4 mL (3.3–18.9 mL). We found shrinkage of the treated pituitary adenoma in all patients. Within a median follow-up of 63 months (28–100 months) an absolute mean volume reduction of 3.8 mL (0.9–12.4 mL) was seen. The mean relative size reduction compared with the volume before radiotherapy was 51% (22%–95%). Shrinkage measured by 3D MRI was greater at longer time intervals after radiotherapy. A strong negative correlation between the initial tumor volume and the absolute volume reduction after FSRT was found. There was no correlation between tumor size reduction and patient age, sex, or number of previous surgeries. Conclusions: By using 3D MRI in all patients undergoing FSRT of an NFPA, tumor shrinkage is detected. Our data demonstrate that volumetric assessment based on 3D MRI adds additional information to routinely used radiological response measurements. After FSRT a mean relative size reduction of 51% can be expected within 5 years.

  17. Preliminary Experience in Treatment of Papillary and Macular Retinoblastoma: Evaluation of Local Control and Local Complications After Treatment With Linear Accelerator-Based Stereotactic Radiotherapy With Micromultileaf Collimator as Second-Line or Salvage Treatment After Chemotherapy

    Purpose: To determine the local control and complication rates for children with papillary and/or macular retinoblastoma progressing after chemotherapy and undergoing stereotactic radiotherapy (SRT) with a micromultileaf collimator. Methods and Materials: Between 2004 and 2008, 11 children (15 eyes) with macular and/or papillary retinoblastoma were treated with SRT. The mean age was 19 months (range, 2–111). Of the 15 eyes, 7, 6, and 2 were classified as International Classification of Intraocular Retinoblastoma Group B, C, and E, respectively. The delivered dose of SRT was 50.4 Gy in 28 fractions using a dedicated micromultileaf collimator linear accelerator. Results: The median follow-up was 20 months (range, 13–39). Local control was achieved in 13 eyes (87%). The actuarial 1- and 2-year local control rates were both 82%. SRT was well tolerated. Late adverse events were reported in 4 patients. Of the 4 patients, 2 had developed focal microangiopathy 20 months after SRT; 1 had developed a transient recurrence of retinal detachment; and 1 had developed bilateral cataracts. No optic neuropathy was observed. Conclusions: Linear accelerator-based SRT for papillary and/or macular retinoblastoma in children resulted in excellent tumor control rates with acceptable toxicity. Additional research regarding SRT and its intrinsic organ-at-risk sparing capability is justified in the framework of prospective trials.

  18. Preliminary Experience in Treatment of Papillary and Macular Retinoblastoma: Evaluation of Local Control and Local Complications After Treatment With Linear Accelerator-Based Stereotactic Radiotherapy With Micromultileaf Collimator as Second-Line or Salvage Treatment After Chemotherapy

    Pica, Alessia, E-mail: Alessia.Pica@chuv.ch [Department of Radiation Oncology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Moeckli, Raphael [University Institute for Radiation Physics, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Balmer, Aubin [Department of Radiation Oncology, Jules Gonin Eye Hospital, Lausanne (Switzerland); Beck-Popovic, Maja [Unit of Pediatric Oncology, University of Lausanne, Lausanne (Switzerland); Chollet-Rivier, Madeleine [Department of Anesthesiology, University of Lausanne, Lausanne (Switzerland); Do, Huu-Phuoc [University Institute for Radiation Physics, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Weber, Damien C. [Department of Radiation Oncology, Geneva University Hospital, University of Geneva, Geneva (Switzerland); Munier, Francis L. [Department of Radiation Oncology, Jules Gonin Eye Hospital, Lausanne (Switzerland)

    2011-12-01

    Purpose: To determine the local control and complication rates for children with papillary and/or macular retinoblastoma progressing after chemotherapy and undergoing stereotactic radiotherapy (SRT) with a micromultileaf collimator. Methods and Materials: Between 2004 and 2008, 11 children (15 eyes) with macular and/or papillary retinoblastoma were treated with SRT. The mean age was 19 months (range, 2-111). Of the 15 eyes, 7, 6, and 2 were classified as International Classification of Intraocular Retinoblastoma Group B, C, and E, respectively. The delivered dose of SRT was 50.4 Gy in 28 fractions using a dedicated micromultileaf collimator linear accelerator. Results: The median follow-up was 20 months (range, 13-39). Local control was achieved in 13 eyes (87%). The actuarial 1- and 2-year local control rates were both 82%. SRT was well tolerated. Late adverse events were reported in 4 patients. Of the 4 patients, 2 had developed focal microangiopathy 20 months after SRT; 1 had developed a transient recurrence of retinal detachment; and 1 had developed bilateral cataracts. No optic neuropathy was observed. Conclusions: Linear accelerator-based SRT for papillary and/or macular retinoblastoma in children resulted in excellent tumor control rates with acceptable toxicity. Additional research regarding SRT and its intrinsic organ-at-risk sparing capability is justified in the framework of prospective trials.

  19. Comparison of long-term survival and toxicity of simultaneous integrated boost vs conventional fractionation with intensity-modulated radiotherapy for the treatment of nasopharyngeal carcinoma

    Tao, Hengmin; Wei, Yumei; Huang, Wei; Gai, Xiujuan; Li, Baosheng

    2016-01-01

    Aim In recent years, the intensity-modulated radiotherapy with simultaneous integrated boost (IMRT-SIB) and intensity-modulated radiotherapy with conventional fractionation (IMRT-CF) have been involved in the treatment of nasopharyngeal carcinoma (NPC). However, the potential clinical effects and toxicities are still controversial. Methods Here, 107 patients with biopsy-proven locally advanced NPC between March 2004 and January 2011 were enrolled in the retrospective study. Among them, 54 patients received IMRT-SIB, and 53 patients received IMRT-CF. Subsequently, overall survival (OS), 5-year progression-free survival (PFS), 5-year locoregional recurrence-free survival (LRFS), and relevant toxicities were analyzed. Results In the present study, all patients completed the treatment, and the overall median follow-up time was 80 months (range: 8–126 months). The 5-year OS analysis revealed no significant difference between the IMRT-SIB and IMRT-CF groups (80.9% vs 80.5%, P=0.568). In addition, there were also no significant between-group differences in 5-year PFS (73.3% vs 74.4%, P=0.773) and 5-year LRFS (88.1% vs 90.8%, P=0.903). Notably, the dose to critical organs (spinal cord, brainstem, and parotid gland) in patients treated by IMRT-CF was significantly lower than that in patients treated by IMRT-SIB (all Pxerostomia. Further prospective study is warranted to confirm our findings. PMID:27099518

  20. Experimental research of dose distribution and protection for mobile intra-operative radiotherapy accelerator in operating room

    Objective: To study the dose distribution characteristics for mobile intra-operative radiotherapy accelerator (Mobetron) in an operating room, and to provide basic data for developing appropriate radiation protection measures and protection standard. Methods: For most commonly used electron energy 9 MeV, TLD dosimeters were placed at 50, 100, 150 and 200 cm high plane, respectively. For each plane,the measurement points were selected at every 50 cm from the central axis at every 45° at eight different directions. Also different electron energies, such as 4, 6, 9 and 12 MeV, were taken into consideration at the plane at 100 cm height. After 10 Gy with a dose rate of 10 Gy/min were delivered, the TLD dosimeters were used to read out the data. Results: For 9 MeV, at the phantom plane (100 cm high plane), the average doses were 169, 756, 395 and 241 μSv at 50, 100, 150 and 200 cm from the central axis,respectively. The maximum deviation between the doses at 50 cm from the central axis in different angles and their average values were 9.1%. In the identical angle, the average doses of 50, 100, 150 and 200 cm high planes at the distance of 100 cm from central axis were 527, 756, 570 and 141 μSv, respectively. For the energies of 4, 6, 9 and 12 MeV, the average doses were 573, 486, 689 and 781 μSv at 100 cm from the central axis at 90° of 100 cm high plane. Conclusions: For the same energy,the dose values at different directions were decreased by the minus exponential function law with the distance. The doses were uniformly distributed at different directions at the same distance from the central axis. The doses on the plane of 100 cm height were much higher than those at other heights,and the dose values were increased with the election energy. (authors)

  1. Exclusive radiotherapy and concurrent endocrine therapy for the management of elderly breast cancer patients: Case study and review of hypo-fractionated schemes; Hormonoradiotherapie exclusive dans la prise en charge du cancer du sein de la personne agee: cas clinique et revue de la litterature des schemas hypofractionnes

    Auberdiac, P.; Cartier, L.; Malkoun, N.; Chauleur, C.; De Laroche, G.; Magne, N. [Departement de radiotherapie, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France); Chargari, C. [Service d' oncologie radiotherapie, hopital d' instruction des armees du Val-de-Grace, 74, boulevard de Port-Royal, 75230 Paris cedex 5 (France); Melis, A.; Jacquin, J.P. [Departement d' oncologie medicale, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France)

    2011-12-15

    Normo-fractionated radiotherapy is standard for adjuvant management of patients treated with breast conservative surgery for breast cancer. However, many elderly patients are not eligible to such strategy, either because of concurrent diseases, or because the tumor is inoperable. Several protocols of exclusive radiotherapy have been reported in the literature, frequently using hypo-fractionated radiotherapy and endocrine therapy. We report a case of a patient treated with exclusive endocrine and radiotherapy and address the state of the art on hypo-fractionated schemes for the management of elderly breast cancer patients. While hypo-fractionated radiotherapy does not compromise the oncologic or cosmetic outcome, there is no prospective data that assesses the place of radiotherapy for the exclusive treatment of elderly patients. This strategy should be further assessed in clinical randomized trial. (authors)

  2. Dosimetric consequences of inter-fraction breathing-pattern variation on radiotherapy with personalized motion-assessed margins

    Kavanagh, A.; McQuaid, D.; Evans, P.; Webb, S.; Guckenberger, M.

    2011-11-01

    The data from eight patients who had undergone stereotactic body radiotherapy were selected due to their 4D-CT planning scans showing that their tumours had respiratory induced motion trajectories of large amplitude (greater than 9 mm in cranio-caudal direction). Radiotherapy plans with personalized motion-assessed margins were generated for these eight patients. The margins were generated by inverse 4D planning on an eight-bin phase-sorted 4D-CT scan. The planning was done on an in-house software system with a non-rigid registration stage being completed using freely available software. The resultant plans were then recalculated on a 4D-CT scan taken later during the course of treatment. Simulated image-guided patient set-up was used to align the geometric centres of the tumour region and minimize any misalignment between the two reconstructions. In general, the variation in the patient breathing patterns was found to be very small. Consequently, the degradation of the mean dose to the tumour region was found to be around a few percent (<3%) and hence was not a large effect.

  3. Development of an ultrasmall C-band linear accelerator guide for a four-dimensional image-guided radiotherapy system with a gimbaled x-ray head.

    Kamino, Yuichiro; Miura, Sadao; Kokubo, Masaki; Yamashita, Ichiro; Hirai, Etsuro; Hiraoka, Masahiro; Ishikawa, Junzo

    2007-05-01

    We are developing a four-dimensional image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB6) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and the average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mm X 0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-Ib (mA) X 0.00808 (MeV/mA), where Ib is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1. PMID:17555261

  4. Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP; Tratamiento hipofraccionado en radioterapia: modelos radiobiologicos TCP y NTCP

    Astudillo V, A. J.; Mitsoura, E. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, 50180 Toluca, Estado de Mexico (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Resendiz G, G., E-mail: lydia.paredes@inin.gob.mx [Hospital Medica Sur, Departamento de Radioterapia, Puente de Piedra 150, Col. Toriello Guerra, 14050 Mexico D. F. (Mexico)

    2014-08-15

    At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

  5. Accelerator

    The invention claims equipment for stabilizing the position of the front covers of the accelerator chamber in cyclic accelerators which significantly increases accelerator reliability. For stabilizing, it uses hydraulic cushions placed between the electromagnet pole pieces and the front chamber covers. The top and the bottom cushions are hydraulically connected. The cushions are disconnected and removed from the hydraulic line using valves. (J.P.)

  6. A prospective randomized comparative clinical trial comparing the efficacy between ondansetron and metoclopramide for prevention of nausea and vomiting in patients undergoing fractionated radiotherapy to the abdominal region

    This study is a prospective randomized clinical trial comparing the efficacy and complication of anti-emetic drugs for prevention of nausea and vomiting after radiotherapy which has moderate emetogenic potential. The aim of this study was to investigate whether the anti-emetic efficacy at ondansetron(Zofran) 8 mg bid dose (Group O) is better than the efficacy of metoclopramide 5 mg tid dose (Group M) in patients undergoing fractionated radiotherapy to the abdominal region. Study entry was restricted to those patients who met the following eligibility criteria: histologically confirmed malignant disease; no distant metastasis; performance status of not more than ECOG grade 2; no previous chemotherapy and radiotherapy. Between March 1997 and February 1998, 60 patients enrolled in this study. All patients signed a written statement of informed consent prior to enrollment. Blinding was maintained by dosing identical number of tables including one dose of matching placebo for Group O. The extent of nausea, appetite loss, and the number of emetic episodes were recorded everyday using diary card. The mean score of nausea, appetite loss and the mean number of emetic episodes were obtained in a weekly interval. Prescription error occurred in one patient. And diary cards have not returned in 3 patients due to premature refusal of treatment. Card from one patient was excluded from the analysis because she had a history of treatment for neurosis. As a result, the analysis consisted of 55 patients. Patient characteristics and radiotherapy characteristics were similar except mean age was 52.9± 11.2 in group M, 46.5±9.6 in group O. The difference of age was statistically significant. The mean score of nausea, appetite loss and emetic episodes in a weekly interval was higher in group M than O. In group M, the symptoms were most significant at 5th week. In a panel data analysis using mixed procedure, treatment group was only significant factor detecting the difference of weekly

  7. A prospective randomized comparative clinical trial comparing the efficacy between ondansetron and metoclopramide for prevention of nausea and vomiting in patients undergoing fractionated radiotherapy to the abdominal region

    Park, Hee Chul; Suh, Chang Ok; Seong, Jin Sil; Cho, Jae Ho; Lim, John Jihoon; Park, Won; Song, Jae Seok; Kim, Gwi Eon [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2001-06-01

    This study is a prospective randomized clinical trial comparing the efficacy and complication of anti-emetic drugs for prevention of nausea and vomiting after radiotherapy which has moderate emetogenic potential. The aim of this study was to investigate whether the anti-emetic efficacy at ondansetron(Zofran) 8 mg bid dose (Group O) is better than the efficacy of metoclopramide 5 mg tid dose (Group M) in patients undergoing fractionated radiotherapy to the abdominal region. Study entry was restricted to those patients who met the following eligibility criteria: histologically confirmed malignant disease; no distant metastasis; performance status of not more than ECOG grade 2; no previous chemotherapy and radiotherapy. Between March 1997 and February 1998, 60 patients enrolled in this study. All patients signed a written statement of informed consent prior to enrollment. Blinding was maintained by dosing identical number of tables including one dose of matching placebo for Group O. The extent of nausea, appetite loss, and the number of emetic episodes were recorded everyday using diary card. The mean score of nausea, appetite loss and the mean number of emetic episodes were obtained in a weekly interval. Prescription error occurred in one patient. And diary cards have not returned in 3 patients due to premature refusal of treatment. Card from one patient was excluded from the analysis because she had a history of treatment for neurosis. As a result, the analysis consisted of 55 patients. Patient characteristics and radiotherapy characteristics were similar except mean age was 52.9{+-} 11.2 in group M, 46.5{+-}9.6 in group O. The difference of age was statistically significant. The mean score of nausea, appetite loss and emetic episodes in a weekly interval was higher in group M than O. In group M, the symptoms were most significant at 5th week. In a panel data analysis using mixed procedure, treatment group was only significant factor detecting the difference of

  8. Combination of peptide receptor radionuclide therapy with fractionated external beam radiotherapy for treatment of advanced symptomatic meningioma

    External beam radiotherapy (EBRT) is the treatment of choice for irresectable meningioma. Due to the strong expression of somatostatin receptors, peptide receptor radionuclide therapy (PRRT) has been used in advanced cases. We assessed the feasibility and tolerability of a combination of both treatment modalities in advanced symptomatic meningioma. 10 patients with irresectable meningioma were treated with PRRT (177Lu-DOTA0,Tyr3 octreotate or - DOTA0,Tyr3 octreotide) followed by external beam radiotherapy (EBRT). EBRT performed after PRRT was continued over 5–6 weeks in IMRT technique (median dose: 53.0 Gy). All patients were assessed morphologically and by positron emission tomography (PET) before therapy and were restaged after 3–6 months. Side effects were evaluated according to CTCAE 4.0. Median tumor dose achieved by PRRT was 7.2 Gy. During PRRT and EBRT, no side effects > CTCAE grade 2 were noted. All patients reported stabilization or improvement of tumor-associated symptoms, no morphologic tumor progression was observed in MR-imaging (median follow-up: 13.4 months). The median pre-therapeutic SUVmax in the meningiomas was 14.2 (range: 4.3–68.7). All patients with a second PET after combined PRRT + EBRT showed an increase in SUVmax (median: 37%; range: 15%–46%) to a median value of 23.7 (range: 8.0–119.0; 7 patients) while PET-estimated volume generally decreased to 81 ± 21% of the initial volume. The combination of PRRT and EBRT is feasible and well tolerated. This approach represents an attractive strategy for the treatment of recurring or progressive symptomatic meningioma, which should be further evaluated

  9. Advances in conformal radiotherapy using Monte Carlo Code to design new IMRT and IORT accelerators and interpret CT numbers

    Wysocka-Rabin, A

    2013-01-01

    The introductory chapter of this monograph, which follows this Preface, provides an overview of radiotherapy and treatment planning. The main chapters that follow describe in detail three significant aspects of radiotherapy on which the author has focused her research efforts. Chapter 2 presents studies the author worked on at the German National Cancer Institute (DKFZ) in Heidelberg. These studies applied the Monte Carlo technique to investigate the feasibility of performing Intensity Modulated Radiotherapy (IMRT) by scanning with a narrow photon beam. This approach represents an alternative to techniques that generate beam modulation by absorption, such as MLC, individually-manufactured compensators, and special tomotherapy modulators. The technical realization of this concept required investigation of the influence of various design parameters on the final small photon beam. The photon beam to be scanned should have a diameter of approximately 5 mm at Source Surface Distance (SSD) distance, and the penumbr...

  10. Fractionated radiotherapy is the main stimulus for the induction of cell death and of Hsp70 release of p53 mutated glioblastoma cell lines

    Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. Despite a multimodal therapy consisting of resection followed by fractionated radiotherapy (RT) combined with the chemotherapeutic agent (CT) temozolomide (TMZ), its recurrence is almost inevitable. Since the immune system is capable of eliminating small tumor masses, a therapy should also aim to stimulate anti-tumor immune responses by induction of immunogenic cell death forms. The histone deacetylase inhibitor valproic acid (VPA) might foster this. Reflecting therapy standards, we applied in our in vitro model fractionated RT with a single dose of 2Gy and clinically relevant concentrations of CT. Not only the impact of RT and/or CT with TMZ and/or VPA on the clonogenic potential and cell cycle of the glioblastoma cell lines T98G, U251MG, and U87MG was analyzed, but also the resulting cell death forms and release of danger signals such as heat-shock protein70 (Hsp70) and high-mobility group protein B1 (HMGB1). The clonogenic assays revealed that T98G and U251MG, having mutated tumor suppressor protein p53, are more resistant to RT and CT than U87MG with wild type (WT) p53. In all glioblastoma cells lines, fractionated RT induced a G2 cell cycle arrest, but only in the case of U87MG, TMZ and/or VPA alone resulted in this cell cycle block. Further, fractionated RT significantly increased the number of apoptotic and necrotic tumor cells in all three cell lines. However, only in U87MG, the treatment with TMZ and/or VPA alone, or in combination with fractionated RT, induced significantly more cell death compared to untreated or irradiated controls. While necrotic glioblastoma cells were present after VPA, TMZ especially led to significantly increased amounts of U87MG cells in the radiosensitive G2 cell cycle phase. While CT did not impact on the release of Hsp70, fractionated RT resulted in significantly increased extracellular concentrations of Hsp70 in p53 mutated and WT glioblastoma

  11. Concurrent hyperfractionated accelerated radiotherapy with 5-FU and once weekly cisplatin in locally advanced head and neck cancer. The 10-year results of a prospective phase II trial

    Budach, V.; Boehmer, D.; Badakhshi, H.; Jahn, U.; Stromberger, C. [Campus Virchow Klinikum, Charite Universitaetsmedizin Berlin, Department for Radiooncology, Clinic for Radiooncology, Berlin (Germany); Becker, E.T. [Charite Universitaetsmedizin, Department of Otorhinolaryngology, Berlin (Germany); Wernecke, K.D. [Sostana Statistics GmbH, Charite Universitaetsmedizin Berlin, Berlin (Germany)

    2014-03-15

    In this study, the acute toxicity and long-term outcome of a hyperfractionated accelerated chemoradiation regimen with cisplatin/5-fluorouracil (5-FU) in patients with locally advanced squamous cell carcinomas of head and neck were evaluated. From 2000-2002, 38 patients with stage III (5.3 %) and stage IV (94.7 %) head and neck cancer were enrolled in a phase II study. Patients received hyperfractionated-accelerated radiotherapy with 72 Gy in 15 fractions of 2 Gy followed by 1.4 Gy twice daily with concurrent, continuous infusion 5-FU of 600 mg/m{sup 2} on days 1-5 and 6 cycles of weekly cisplatin (30 mg/m{sup 2}). Acute toxicities (CTCAEv2.0), locoregional control (LRC), metastases-free (MFS), and overall survival (OS) were analyzed and exploratively compared with the ARO 95-06 trial. Median follow-up was 11.4 years (95 % CI 8.6-14.2) and mean dose 71.6 Gy. Of the patients, 82 % had 6 (n = 15) or 5 (n = 16) cycles of cisplatin, 5 and 2 patients received 4 and 3 cycles, respectively. Grade 3 anemia, leukopenia, and thrombocytopenia were observed in 15.8, 15.8, and 2.6 %, respectively. Grade 3 mucositis in 50 %, grade 3 and 4 dysphagia in 55 and 13 %. The 2-, 5-, and 10-year LRC was 65, 53.6, and 48.2 %, the MFS was 77.5, 66.7, and 57.2 % and the OS 59.6, 29.2, and 15 %, respectively. Chemoradiation with 5-FU and cisplatin seems feasible and superior in terms of LRC and OS to the ARO 95-06C-HART arm at 2 years. However, this did not persist at the 5- and 10-year follow-ups. (orig.) [German] Untersuchung der Akuttoxizitaet und des Langzeitueberlebens einer hyperfraktioniert-akzelerierten simultanen Radiochemotherapie mit Cisplatin/5-Fluorouracil (5-FU) bei Patienten mit lokal fortgeschrittenen Kopf-Hals-Tumoren. Von 2000 bis 2002 wurden 38 Patienten mit Plattenepithelkarzinomen der Kopf-Hals-Region im Stadium III (5,3 %) und IV (94,7 %) eingeschlossen. Es erfolgte eine simultane hyperfraktionierte akzelerierte Radiochemotherapie mit 72 Gy in 15 Fraktionen a 2 Gy

  12. Studies on serum protein fractions of patients with maxillary sinus cancer undergoing a combination of radiotherapy and chemotherapy. 2. Relationship between changes in serum protein fractions and prognosis

    We examined the correlations between changes in serum protein fractions and the prognosis of the patients. The levels of 21 protein components of the sera of 36 patients with maxillary sinus cancer were determined by a single radial immunodiffusion method before and after radiation therapy. The patients with maxillary sinus cancer were treated with combined intra-arterial infusion of bleomycin and external irradiation of 60 Co gamma-rays, and were concurrently treated with 5-fluorouracil at 200 mg/day p.o. The levels of the same protein components were also measured in 34 normal adult as a control. All patients were observed 5 years and 12 years after radiation therapy. In patients who had survived at least 5 years after radiation therapy, the Alb, Tf, Hx, IgG and IgM levels measured before radiation therapy were elevated significantly compared with those who had died within 5 years. In those who had survived at least 5 years, the Alb, Tf, Hx, IgG, IgM, IgA and IαI levels measured after radiation therapy were elevated significantly compared with those who had died within 5 years, and AT III was reduced. In cases of maxillary sinus cancer following a period of 5 to 12 years after radiation therapy, multiple regression analysis was used to determine whether increased concentrations of serum protein fractions were associated with good prognosis for the original disease. α2HS, IgM, HX, α1AT and α1X before radiation therapy were positively correlated with survival, whereas AT III, Pmg, Cp, IgA, and α1AG showed negative correlations. After radiation therapy, Pmg, Hx, Cp, Cl inh and Fib were found to be positive factors of survival rate, whereas α2M, α2PI, IαI, IgA, α1AG and C3 were negative factors. (author). 54 refs

  13. Solutions that enable ablative radiotherapy for large liver tumors: Fractionated dose painting, simultaneous integrated protection, motion management, and computed tomography image guidance.

    Crane, Christopher H; Koay, Eugene J

    2016-07-01

    The emergence and success of stereotactic body radiation therapy (SBRT) for the treatment of lung cancer have led to its rapid adoption for liver cancers. SBRT can achieve excellent results for small liver tumors. However, the vast majority of physicians interpret SBRT as meaning doses of radiation (range, 4-20 Gray [Gy]) that may not be ablative but are delivered within about 1 week (ie, in 3-6 fractions). Adherence to this approach has limited the effectiveness of SBRT for large liver tumors (>7 cm) because of the need to reduce doses to meet organ constraints. The prognosis for patients who present with large liver tumors is poor, with a median survival ≤12 months, and most of these patients die from tumor-related liver failure. Herein, the authors present a comprehensive solution to achieve ablative SBRT doses for patients with large liver tumors by using a combination of classic, modern, and novel concepts of radiotherapy: fractionation, dose painting, motion management, image guidance, and simultaneous integrated protection. The authors discuss these concepts in the context of large, inoperable liver tumors and review how this approach can substantially prolong survival for patients, most of whom otherwise have a very poor prognosis and few effective treatment options. Cancer 2016;122:1974-86. © 2016 American Cancer Society. PMID:26950735

  14. Early Treatment Response Monitoring Using 2-Deoxy-2-[18F]fluoro-D-glucose Positron Emission Tomography Imaging during Fractionated Radiotherapy of Head Neck Cancer Xenografts

    Jiayi Huang

    2014-01-01

    Full Text Available Background. To determine the optimal timing and analytic method of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (PET imaging during fractionated radiotherapy (RT to predict tumor control. Methods. Ten head neck squamous cell carcinoma xenografts derived from the UT-14-SCC cell line were irradiated with 50 Gy at 2 Gy per day over 5 weeks. Dynamic PET scans were acquired over 70 minutes at baseline (week 0 and weekly for seven weeks. PET data were analyzed using standard uptake value (SUV, retention index (RI, sensitivity factor (SF, and kinetic index (Ki. Results. Four xenografts had local failure (LF and 6 had local control. Eighty scans from week 0 to week 7 were analyzed. RI and SF after 10 Gy appeared to be the optimal predictors for LF. In contrast, SUV and Ki during RT were not significant predictors for LF. Conclusion. RI and SF of PET obtained after the first week of fractionated RT were the optimal methods and timing to predict tumor control.

  15. Comparison of two radiotherapy schemes, conventional and fractionated, in elderly patients suffering from a locally advanced rectum cancer; Comparaison de deux schemas de radiotherapie, classique et hypofractionne, chez les patients ages atteints d'un cancer du rectum localement evolue

    Guillerme, F.; Clavier, J.B.; Guihard, S.; Schumacher, C.; Nehme-Schuster, H.; Ben Abdelghani, M.; Noel, G. [Centre Paul-Strauss, Strasbourg (France); Kurtz, J.E.; Brigand, C. [Hopitaux universitaires, Strasbourg (France)

    2011-10-15

    Based on results obtained on 177 patients older than 65 and suffering from T3-4 rectum cancer, and treated either according to a conventional scheme (45 to 50,4 Gy by 1,8 to 2 Gy fractions) or according to a fractionated scheme (39 Gy by 3 Gy fractions), the authors report the comparison of these both methods in terms of toxicity, delay between end of radiotherapy and surgery), histological response, global survival. The hypo-fractionated treatment allows the treatment duration to be reduced, is therefore less constraining and seems more suitable for elderly people. Short communication

  16. Multiple daily fractionation (MDF) radiotherapy in association with hyperthermia and/or misonidazole: experimental and clincial results

    Several modalities involving a Multiple Daily Fractionation (MDF) course in combination with hyperthermia and/or the hypoxic sensitizer misonidazole were tested on a mouse tumor system and then applied, with the proper sequencing, to a group of patients with multiple neck node metastases from H and N cancers. Different lesions of the same patients underwent different modalities. The clinical results indicate the effectiveness, in respect to a historical series of patients treated with conventional fractionation, of either MDF alone, or MDF + hyperthermia, or MDF + misonidazole, or MDF + hyperthermia + misonidazole. The latter modality appears to be possibly the most effective at inducing a complete local tumor response lasting longer in time. The pharmacology of misonidazole was monitored in the patients to avoid undesired excessive drug plasma level. No neurological symptoms were observed. Oropharyngeal mucositis was observed only in patients treated with misonidazole and radiation through two cross-firing portals. The problem of selecting individual patients for a particular modality is discussed

  17. Clinical Study of the Necessity of Replanning Before the 25th Fraction During the Course of Intensity-Modulated Radiotherapy for Patients With Nasopharyngeal Carcinoma

    Purpose: To quantify the target and normal structures on dose distributing variations during intensity-modulated radiotherapy (IMRT) and to assess the value of replanning for nasopharyngeal carcinoma (NPC) patients. Methods and Materials: Twenty-eight NPC patients treated with IMRT were recruited. The IMRT was delivered in 33 fractions, to 70 to 76Gy, to the gross tumor volume (GTV). Before the 25th fraction of IMRT, a new simulation computed tomography (CT) scan was acquired for all patients. According to the dose constraint criterion in the Radiation Therapy Oncology Group (RTOG) 0225 protocol, the replanning was generated on the new simulation CT. With the Quality Assessment Center of a CORVUS 6.3 treatment planning system, a phantom plan was generated for each patient by applying the beam configurations of the initial plan to the anatomy of the new simulation CT. The dose-volume histograms of the phantom plan were compared with the replanning. Results: The percentage of prescription dose delivered to the clinical target volume (CTV1) was significantly increased by 4.91% ± 10.89%, whereas the maximum dose to the spinal cord, mean dose to the left parotid, and V30 to the right parotid were significantly decreased by 5.00 ± 9.23Gy, 4.23 ± 10.03Gy, and 11.47% ± 18.89% respectively in the replanning, compared with the phantom plan (p < 0.05). Based on the dose constraint criterion in the RTOG0225 protocol, 50% of phantom plans (14/28) were out of limit for the dose to the normal critical structures, whereas no plan was out of limit in replanning (p < 0.001). Conclusion: Replanning for patients with NPC before the 25th fraction during IMRT helps to ensure adequate dose to the target volumes and safe doses to critical normal structures.

  18. Later Outcomes and Alpha/Beta Estimate From Hypofractionated Conformal Three-Dimensional Radiotherapy Versus Standard Fractionation for Localized Prostate Cancer

    Purpose: Now that the follow-up time has exceeded 5 years, an estimate of the α/β ratio can be presented. The additional late outcomes in patients treated with three-dimensional conformal external beam radiotherapy for localized prostate cancer using a hypofractionated vs. a standard fractionation regimen are reported from this prospective nonrandomized contemporary comparison. Methods and Materials: A total of 114 nonrandomized patients chose hypofractionation delivered in 20 fractions of 3 Gy or 3.15 Gy (mean 3.06 Gy) for localized prostate cancer within a median overall time of 32 days (range, 29–49) using four fractions weekly. A total of 160 comparable patients were contemporarily treated within a median of 55 days (range 49-66). The median follow-up was 66 months (range, 24–95) for the hypofractionated arm and 63 months (range, 36–92) for the standard arm. The percentage of patients in the low-, medium-, and high-risk groups was 36%, 46%, and 18% in the hypofractionated arm and 44%, 50%, and 6% in standard arm (2 Gy), respectively. Results: The 5-year actuarial biochemical absence of disease (prostate-specific antigen nadir + 2 ng/mL) and disease-free survival rate was the same at 89% in both arms, making the α/β calculation unambiguous. The point ratio of α/β was 1.86 (95% confidence interval, 0.7–5.1 Gy). The 95% confidence interval was determined entirely by the binomial confidence limits in the numbers of patients. Rectal reactions of grade 3 and 4 occurred in 1 of 114 (hypofractionated) and 2 of 160 (standard) patients. Conclusions: The presented three-dimensional conformal regimen was acceptable, and the α/β value was 1.8, in agreement with other very recent low meta-analyses (reviewed in the “” section).

  19. Repeated tumor pO2 measurements by multi-site EPR oximetry as a prognostic marker for enhanced therapeutic efficacy of fractionated radiotherapy

    Purpose: To investigate the temporal effects of single or fractionated radiotherapy on subcutaneous RIF-1 tumor pO2 and to determine the therapeutic outcomes when the timing of fractionations is guided by tumor pO2. Methods: The time-course of the tumor pO2 changes was followed by multi-site electron paramagnetic resonance (EPR) oximetry. The tumors were treated with single 10, 20, and 10 Gy x 2 doses, and the tumor pO2 was measured repeatedly for six consecutive days. In the 10 Gy x 2 group, the second dose of 10 Gy was delivered at a time when the tumors were either relatively oxygenated or hypoxic. The changes in tumor volumes were followed for nine days to determine the therapeutic outcomes. Results: A significant increase in tumor pO2 was observed at 24 h post 10 Gy, while 20 Gy resulted in a significant increase in tumor pO2 at 72-120 h post irradiation. The tumors irradiated with a second dose of 10 Gy at 24 h, when the tumors were oxygenated, had a significant increase in tumor doubling times (DTs), as compared to tumors treated at 48 h when they were hypoxic (p 2 repeatedly during fractionated schemes to optimize radiotherapeutic outcome. This technique could also be used to identify responsive and non-responsive tumors, which will facilitate the design of other therapeutic approaches for non-responsive tumors at early time points during the course of therapy.

  20. Carbon-ion radiotherapy for marginal lymph node recurrences of cervical cancer after definitive radiotherapy: a case report

    Recurrences of cervical cancer after definitive radiotherapy often occur at common iliac or para-aortic lymph nodes as marginal lymph node recurrences. Patients with these recurrences have a chance of long-term survival by optimal re-treatment with radiotherapy. However, the re-irradiation often overlaps the initial and the secondary radiotherapy fields and can result in increased normal tissue toxicities in the bowels or the stomach. Carbon-ion radiotherapy, a form of particle beam radiotherapy using accelerated carbon ions, offers more conformal and sharp dose distribution than X-ray radiotherapy. Therefore, this approach enables the delivery of high radiation doses to the target while sparing its surrounding normal tissues. Marginal lymph node recurrences in common iliac lymph nodes after radiotherapy were treated successfully by carbon-ion radiotherapy in two patients. These two patients were initially treated with a combination of external beam radiotherapy and intracavitary and interstitial brachytherapy. However, the diseases recurred in the lymph nodes near the border of the initial radiotherapy fields after 22 months and 23 months. Because re-irradiation with X-ray radiotherapy may deliver high doses to a section of the bowels, carbon-ion radiotherapy was selected to treat the lymph node recurrences. A total dose of 48 Gy (RBE) in 12 fractions over 3 weeks was given to the lymph node recurrences, and the tumors disappeared completely with no severe acute toxicities. The two patients showed no evidence of disease for 75 months and 63 months after the initial radiotherapy and for 50 months and 37 months after the carbon-ion radiotherapy, respectively. No severe late adverse effects are observed in these patients. The two presented cases suggest that the highly conformal dose distribution of carbon-ion radiotherapy may be beneficial in the treatment of marginal lymph node recurrences after radiotherapy. In addition, the higher biological effect of carbon

  1. SU-C-BRF-02: Surface Imaging Based Analysis of Intra-Fraction Motion for Breast Radiotherapy Patients

    Purpose: To quantify and characterize intrafraction motion for breast radiotherapy treatments using 3D surface imaging. Methods: Thirty free breathing breast patients were monitored with 3D surface imaging over a total of 831 monitoring sessions. Mean translations and rotations were calculated over each minute, each session, and over all sessions combined. The percentage of each session that the root mean square (RMS) of the linear translations were outside of 2 mm, 3 mm, 4 mm, and 5 mm were determined for each patient. Correlations between mean translations per minute and time and between standard deviation per minute and time were evaluated using Pearson's r value. Results: The mean RMS translation averaged over all patients was 2.63 mm +/- 1.63 mm. The patients spent an average of 52%, 24%, 11%, and 5% of the monitoring time outside of 2 mm, 3 mm, 4 mm, and 5 mm RMS tolerances, respectively. The RMS values averaged over all patients were 2.95 mm +/- 1.67 mm, 3.21 +/- 2.11, and 3.57 mm +/- 2.23 mm over the 5th, 10th, and 15th minutes of monitoring, respectively. The RMS values (r = 0.95, p = 0) and the standard deviations of the RMS values (r = 0.97, p = 0) both showed strong significant correlations with time. Conclusion: The majority of patients treatment time is spent within 5 mm of the isocenter. Patient position tends to drift with increasing time in the session. Treatment length should be considered when determining planning margins. An 8 mm margin on a target volume would account for two standard deviations of motion for a treatment up to 15 minutes in length

  2. Accelerated partial breast irradiation using once-daily fractionation: analysis of 312 cases with four years median follow-up

    Shaikh Arif Y

    2012-02-01

    Full Text Available Abstract Background There are limited data on accelerated partial breast irradiation (APBI using external beam techniques. Moreover, there are recent reports of increased fibrosis and unacceptable cosmesis with APBI using external beam with BID fractionation. We adopted a once daily regimen of APBI with fractionation similar to that shown to be effective in a Canadian randomized trial of whole breast irradiation. It is unclear whether patients with DCIS or invasive lobular carcinoma (ILC are suitable for APBI. Methods The retrospective cohort included 310 patients with 312 tumors of T1-T2N0-N1micM0 invasive ductal carcinoma (IDC, ILC, or Tis (DCIS treated with APBI via external beam. Most patients were treated using IMRT with 16 daily fractions of 270 cGy to a dose of 4320 cGy. The target volume included the lumpectomy cavity plus 1.0 cm to account for microscopic disease and an additional 0.5 to 1.0 cm for setup uncertainty and breathing motion. Ipsilateral breast failure (IBF was pathologically confirmed as a local failure (LF or an elsewhere failure (EF. Results Median follow-up was 49 months. Among the 312 cases, 213 were IDC, 31 ILC, and 68 DCIS. Median tumor size was 1.0 cm. There were 9 IBFs (2.9% including 5 LFs and 4 EFs. The IBF rates among patients with IDC, ILC, and DCIS were 2.4%, 3.2%, and 4.4%, respectively, with no significant difference between histologies. When patients were analyzed by the ASTRO APBI consensus statement risk groups, 32% of treated cases were considered suitable, 50% cautionary, and 18% unsuitable. The IBF rates among suitable, cautionary, and unsuitable patients were 4.0%, 2.6%, and 1.8%, respectively, with no significant difference between risk groups. Acute skin reactions were rare and long-term cosmetic outcome was very good to excellent. Conclusions External beam APBI with once daily fractionation has a low rate of IBF consistent with other published APBI studies. The ASTRO risk stratification did not

  3. Accelerated partial breast irradiation using once-daily fractionation: analysis of 312 cases with four years median follow-up

    There are limited data on accelerated partial breast irradiation (APBI) using external beam techniques. Moreover, there are recent reports of increased fibrosis and unacceptable cosmesis with APBI using external beam with BID fractionation. We adopted a once daily regimen of APBI with fractionation similar to that shown to be effective in a Canadian randomized trial of whole breast irradiation. It is unclear whether patients with DCIS or invasive lobular carcinoma (ILC) are suitable for APBI. The retrospective cohort included 310 patients with 312 tumors of T1-T2N0-N1micM0 invasive ductal carcinoma (IDC), ILC, or Tis (DCIS) treated with APBI via external beam. Most patients were treated using IMRT with 16 daily fractions of 270 cGy to a dose of 4320 cGy. The target volume included the lumpectomy cavity plus 1.0 cm to account for microscopic disease and an additional 0.5 to 1.0 cm for setup uncertainty and breathing motion. Ipsilateral breast failure (IBF) was pathologically confirmed as a local failure (LF) or an elsewhere failure (EF). Median follow-up was 49 months. Among the 312 cases, 213 were IDC, 31 ILC, and 68 DCIS. Median tumor size was 1.0 cm. There were 9 IBFs (2.9%) including 5 LFs and 4 EFs. The IBF rates among patients with IDC, ILC, and DCIS were 2.4%, 3.2%, and 4.4%, respectively, with no significant difference between histologies. When patients were analyzed by the ASTRO APBI consensus statement risk groups, 32% of treated cases were considered suitable, 50% cautionary, and 18% unsuitable. The IBF rates among suitable, cautionary, and unsuitable patients were 4.0%, 2.6%, and 1.8%, respectively, with no significant difference between risk groups. Acute skin reactions were rare and long-term cosmetic outcome was very good to excellent. External beam APBI with once daily fractionation has a low rate of IBF consistent with other published APBI studies. The ASTRO risk stratification did not differentiate a subset of patients with a higher rate of IBF

  4. Normal tissue complication models for clinically relevant acute esophagitis (≥ grade 2) in patients treated with dose differentiated accelerated radiotherapy (DART-bid)

    One of the primary dose-limiting toxicities during thoracic irradiation is acute esophagitis (AE). The aim of this study is to investigate dosimetric and clinical predictors for AE grade ≥ 2 in patients treated with accelerated radiotherapy for locally advanced non-small cell lung cancer (NSCLC). 66 NSCLC patients were included in the present analysis: 4 stage II, 44 stage IIIA and 18 stage IIIB. All patients received induction chemotherapy followed by dose differentiated accelerated radiotherapy (DART-bid). Depending on size (mean of three perpendicular diameters) tumors were binned in four dose groups: <2.5 cm 73.8 Gy, 2.5–4.5 cm 79.2 Gy, 4.5–6 cm 84.6 Gy, >6 cm 90 Gy. Patients were treated in 3D target splitting technique. In order to estimate the normal tissue complication probability (NTCP), two Lyman models and the cutoff-logistic regression model were fitted to the data with AE ≥ grade 2 as statistical endpoint. Inter-model comparison was performed with the corrected Akaike information criterion (AICc), which calculates the model’s quality of fit (likelihood value) in relation to its complexity (i.e. number of variables in the model) corrected by the number of patients in the dataset. Toxicity was documented prospectively according to RTOG. The median follow up was 686 days (range 84–2921 days), 23/66 patients (35 %) experienced AE ≥ grade 2. The actuarial local control rates were 72.6 % and 59.4 % at 2 and 3 years, regional control was 91 % at both time points. The Lyman-MED model (D50 = 32.8 Gy, m = 0.48) and the cutoff dose model (Dc = 38 Gy) provide the most efficient fit to the current dataset. On multivariate analysis V38 (volume of the esophagus that receives 38 Gy or above, 95 %-CI 28.2–57.3) was the most significant predictor of AE ≥ grade 2 (HR = 1.05, CI 1.01–1.09, p = 0.007). Following high-dose accelerated radiotherapy the rate of AE ≥ grade 2 is slightly lower than reported for concomitant radio-chemotherapy with the

  5. Dosimetric Characteristics of Circular 6-MeV X-Ray Beams for Stereotactic Radiotherapy with a Linear Accelerator

    Wysocka, A.; Rostkowska, J.; Kania, M.; Bulski, W.; Fijuth, J.

    2000-01-01

    Dosimetric characteristics of 6 MeV circular X-ray beams of diameters ranging from 7.5 to 35.0 mm are reported. The 6-MeV X-ray beam from Clinac 2300CD was formed using additional cylindrical BrainLAB's collimators. The mechanical stability of the entire system was verified. Specific quantities measured include tissue maximum ratios (TMR), beam profiles (off-axis ratios OAR) and relative output factors. Measurements of these parameters were performed in a water phantom using small cylindrical ionization chambers and a diamond detector. Comparison of TMR values measured with the ionization chamber and the diamond detector showed no significant differences. It was shown that the latter yields more accurate results for beam profiles than ionization chambers. The mechanical and dosimetric characteristics of this radiotherapy unit are found to be suitable for stereotactic radiosurgery and radiotherapy.

  6. The state of the art for radiotherapy for brain tumors: Nonconventional fractionation, heavy ions, and fast-neutron therapy

    A variety of new radiation therapy approaches are under investigation in an effort to improve the therapeutic ratio (i.e., to increase the number of tumor cells killed with decreased normal tissue damage): (1) Nonconventional fractionation, (2) Heavy ions and pions, (3) Protons, (4) Fast neutrons, (5) Brachytherapy, (6) Radiosurgery, (7) Photodynamic treatment, (8) Adjuvant chemotherapy, (9) Targeted radionuclides, and (10) Hyperthermia. This paper reviews the rationale and presents the status of these techniques, concluding with a discussion of the limitations of these techniques and of the potential of Boron Neutron Capture Therapy (BNCT) in this setting

  7. External beam radiotherapy plus single-fraction high dose rate brachytherapy in the treatment of locally advanced prostate cancer

    Purpose: To evaluate the efficacy and toxicity of external beam radiation therapy (EBRT) plus high-dose-rate brachytherapy (HDRB) as a boost in patients (pts) with intermediate or high-risk prostate cancer. Methods and materials: From 2002 to July 2012, 377 pts with a diagnosis of intermediate or high-risk prostate cancer were treated with EBRT plus HDRB. Median patient age was 66 years (range, 41–86). Most patients (347 pts; 92%) were classified as high-risk (stage T2c–T3, or PSA > 20 ng/mL, or GS ⩾ 8), with 30 patients (8%) considered intermediate risk. All patients underwent EBRT at a prescribed dose of 60.0 Gy (range, 45–70 Gy) to the prostate and seminal vesicles. A total of 120 pts (31%) received a dose of 46 Gy (45–50 Gy) to the true pelvis. All pts received a single-fraction 9 Gy (9–15 Gy) HDR boost. Most patients (353; 94%) were prescribed complete androgen deprivation therapy (ADT). Overall survival (OS), cause-specific survival (CSS), and biochemical relapse-free survival (BRFS) rates were calculated. In the case of BRFS, patients with <26 months of follow-up (n = 106) were excluded to minimize the impact of ADT. Results: The median follow-up for the entire sample was 50 months (range, 12–126), with 5-year actuarial OS and CSS, respectively, of 88% (95% confidence interval [CI]: 84–92) and 98% (95% CI: 97–99). The 5-year BRFS was 91% (95% CI: 87–95) in the 271 pts with ⩾26 months (median, 60 months) of follow-up. Late toxicity included grade 2 and 3 gastrointestinal toxicity in 17 (4.6%) and 6 pts (1.6%), respectively, as well as grades 2 and 3 genitourinary toxicity in 46 (12.2%) and 3 pts (0.8%), respectively. Conclusion: These long-term outcomes confirm that EBRT plus a single-fraction HDRB boost provides good results in treatment-related toxicity and biochemical control. In addition to the excellent clinical results, this fractionation schedule reduces physician workload, treatment-related expenses, patient discomfort and risks

  8. Effects of beam interruption time on tumor control probability in single-fractionated carbon-ion radiotherapy for non-small cell lung cancer

    Carbon-ion radiotherapy treatment plans are designed on the assumption that the beams are delivered instantaneously, irrespective of actual dose-delivery time structure in a treatment session. As the beam lines are fixed in the vertical and horizontal directions at our facility, beam delivery is interrupted in multi-field treatment due to the necessity of patient repositioning within the fields. Single-fractionated treatment for non-small cell lung cancer (NSCLC) is such a case, in which four treatment fields in multiple directions are delivered in one session with patient repositioning during the session. The purpose of this study was to investigate the effects of the period of dose delivery, including interruptions due to patient repositioning, on tumor control probability (TCP) of NSCLC. All clinical doses were weighted by relative biological effectiveness (RBE) evaluated for instantaneous irradiation. The rate equations defined in the microdosimetric kinetic model (MKM) for primary lesions induced in DNA were applied to the single-fractionated treatment of NSCLC. Treatment plans were made for an NSCLC case for various prescribed doses ranging from 25 to 50 Gy (RBE), on the assumption of instantaneous beam delivery. These plans were recalculated by varying the interruption time τ ranging from 0 to 120 min between the second and third fields for continuous irradiations of 3 min per field based on the MKM. The curative doses that would result in a TCP of 90% were deduced for the respective interruption times. The curative dose was 34.5 Gy (RBE) for instantaneous irradiation and 36.6 Gy (RBE), 39.2 Gy (RBE), 41.2 Gy (RBE), 43.3 Gy (RBE) and 44.4 Gy (RBE) for τ = 0 min, 15 min, 30 min, 60 min and 120 min, respectively. The realistic biological effectiveness of therapeutic carbon-ion beam decreased with increasing interruption time. These data suggest that the curative dose can increase by 20% or more compared to the planned dose if

  9. Effects of beam interruption time on tumor control probability in single-fractionated carbon-ion radiotherapy for non-small cell lung cancer

    Inaniwa, T.; Kanematsu, N.; Suzuki, M.; Hawkins, R. B.

    2015-05-01

    Carbon-ion radiotherapy treatment plans are designed on the assumption that the beams are delivered instantaneously, irrespective of actual dose-delivery time structure in a treatment session. As the beam lines are fixed in the vertical and horizontal directions at our facility, beam delivery is interrupted in multi-field treatment due to the necessity of patient repositioning within the fields. Single-fractionated treatment for non-small cell lung cancer (NSCLC) is such a case, in which four treatment fields in multiple directions are delivered in one session with patient repositioning during the session. The purpose of this study was to investigate the effects of the period of dose delivery, including interruptions due to patient repositioning, on tumor control probability (TCP) of NSCLC. All clinical doses were weighted by relative biological effectiveness (RBE) evaluated for instantaneous irradiation. The rate equations defined in the microdosimetric kinetic model (MKM) for primary lesions induced in DNA were applied to the single-fractionated treatment of NSCLC. Treatment plans were made for an NSCLC case for various prescribed doses ranging from 25 to 50 Gy (RBE), on the assumption of instantaneous beam delivery. These plans were recalculated by varying the interruption time τ ranging from 0 to 120 min between the second and third fields for continuous irradiations of 3 min per field based on the MKM. The curative doses that would result in a TCP of 90% were deduced for the respective interruption times. The curative dose was 34.5 Gy (RBE) for instantaneous irradiation and 36.6 Gy (RBE), 39.2 Gy (RBE), 41.2 Gy (RBE), 43.3 Gy (RBE) and 44.4 Gy (RBE) for τ = 0 min, 15 min, 30 min, 60 min and 120 min, respectively. The realistic biological effectiveness of therapeutic carbon-ion beam decreased with increasing interruption time. These data suggest that the curative dose can increase by 20% or more compared to the planned dose if the

  10. Breast cancer radiotherapy: controversies and prospectives

    YU Jin-ming; WANG Yong-sheng

    2008-01-01

    @@ Despite consensus on breast cancer radiotherapy, there are still some controversies over post-mastectomy radiotherapy (PMRT) in patients with 1-3 positive lymph nodes, accelerated partial breast irradiation (APBI), appropriate sequence of radiotherapy, chemotherapy and hormonal treatment, and radiotherapy after preoperative systemic therapy.

  11. Analysis of quality control data of eight modern radiotherapy linear accelerators: the short- and long-term behaviours of the outputs and the reproducibility of quality control measurements

    Kapanen, Mika [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Tenhunen, Mikko [Department of Oncology, Helsinki University Central Hospital, Haartmaninkatu 4, 00029 Helsinki (Finland); Haemaelaeinen, Tuomo [Department of Oncology, Helsinki University Central Hospital, Haartmaninkatu 4, 00029 Helsinki (Finland); Sipilae, Petri [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Parkkinen, Ritva [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Jaervinen, Hannu [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland)

    2006-07-21

    Quality control (QC) data of radiotherapy linear accelerators, collected by Helsinki University Central Hospital between the years 2000 and 2004, were analysed. The goal was to provide information for the evaluation and elaboration of QC of accelerator outputs and to propose a method for QC data analysis. Short- and long-term drifts in outputs were quantified by fitting empirical mathematical models to the QC measurements. Normally, long-term drifts were well ({<=}1%) modelled by either a straight line or a single-exponential function. A drift of 2% occurred in 18 {+-} 12 months. The shortest drift times of only 2-3 months were observed for some new accelerators just after the commissioning but they stabilized during the first 2-3 years. The short-term reproducibility and the long-term stability of local constancy checks, carried out with a sealed plane parallel ion chamber, were also estimated by fitting empirical models to the QC measurements. The reproducibility was 0.2-0.5% depending on the positioning practice of a device. Long-term instabilities of about 0.3%/month were observed for some checking devices. The reproducibility of local absorbed dose measurements was estimated to be about 0.5%. The proposed empirical model fitting of QC data facilitates the recognition of erroneous QC measurements and abnormal output behaviour, caused by malfunctions, offering a tool to improve dose control.

  12. Analysis of quality control data of eight modern radiotherapy linear accelerators: the short- and long-term behaviours of the outputs and the reproducibility of quality control measurements

    Quality control (QC) data of radiotherapy linear accelerators, collected by Helsinki University Central Hospital between the years 2000 and 2004, were analysed. The goal was to provide information for the evaluation and elaboration of QC of accelerator outputs and to propose a method for QC data analysis. Short- and long-term drifts in outputs were quantified by fitting empirical mathematical models to the QC measurements. Normally, long-term drifts were well (≤1%) modelled by either a straight line or a single-exponential function. A drift of 2% occurred in 18 ± 12 months. The shortest drift times of only 2-3 months were observed for some new accelerators just after the commissioning but they stabilized during the first 2-3 years. The short-term reproducibility and the long-term stability of local constancy checks, carried out with a sealed plane parallel ion chamber, were also estimated by fitting empirical models to the QC measurements. The reproducibility was 0.2-0.5% depending on the positioning practice of a device. Long-term instabilities of about 0.3%/month were observed for some checking devices. The reproducibility of local absorbed dose measurements was estimated to be about 0.5%. The proposed empirical model fitting of QC data facilitates the recognition of erroneous QC measurements and abnormal output behaviour, caused by malfunctions, offering a tool to improve dose control

  13. Commissioning and quality assurance of the X-ray volume Imaging system of an image-guided radiotherapy capable linear accelerator

    Muralidhar K

    2008-01-01

    Full Text Available An Image-Guided Radiotherapy-capable linear accelerator (Elekta Synergy was installed at our hospital, which is equipped with a kV x-ray volume imaging (XVI system and electronic portal imaging device (iViewGT. The objective of this presentation is to describe the results of commissioning measurements carried out on the XVI facility to verify the manufacturer′s specifications and also to evolve a QA schedule which can be used to test its performance routinely. The QA program consists of a series of tests (safety features, geometric accuracy, and image quality. These tests were found to be useful to assess the performance of the XVI system and also proved that XVI system is very suitable for image-guided high-precision radiation therapy.

  14. Locally advanced head and neck cancer treated with accelerated radiotherapy, the hypoxic modifier nimorazole and weekly cisplatin. Results from the DAHANCA 18 phase II study

    Bentzen, Jens; Toustrup, Kasper; Eriksen, Jesper Grau; Primdahl, Hanne; Andersen, Lisbeth Juhler; Overgaard, Jens

    2015-01-01

    150 oropharyngeal cancers. Of these, 112 (79%) were p16 pos and 29 (21%) were p16 neg. LRC for the p16 neg oropharyngeal cancers was poorer than for the p16 pos (74% vs. 91%; p = 0.02). Tube feeding during treatment was necessary for 146 (64%) patients. At 12 months this number was reduced to 6......%. CONCLUSION: The treatment was tolerable in this cohort of locally advanced HNSCC patients. Acute and late toxicity was comparable to similar studies of chemoradiotherapy, and the outcome superior to the data reported in the literature. This strongly indicates that RT of a......PURPOSE/OBJECTIVE: A phase II clinical trial evaluating the feasibility and outcome of treating locally advanced head and neck squamous cell carcinoma (HNSCC) with accelerated radiotherapy, the hypoxic modifier nimorazole and weekly cisplatin. MATERIAL AND METHODS: A total of 227 patients with...

  15. Continuous accelerated 7-days-a-week radiotherapy for head-and-neck cancer: Long-term results of Phase III clinical trial

    Purpose: To update 5-year results of a previously published study on special 7-days-a-week fractionation continuous accelerated irradiation (CAIR) for head-and-neck cancer patients. Methods and Materials: One hundred patients with squamous cell carcinoma of head and neck in Stage T2-4N0-1M were randomized between two definitive radiation treatments: accelerated fractionation 7 days a week including weekends (CAIR) and conventional 5 days a week (control). Hence the overall treatment time was 2 weeks shorter in CAIR. Results: Five-year local tumor control was 75% in the CAIR group and 33% in the control arm (p < 0.00004). Tumor-cure benefit corresponded with significant improvement in disease-free survival and overall survival rates. Confluent mucositis was the main acute toxicity, with the incidence significantly higher in CAIR patients than in control (respectively, 94% vs. 53%). When 2.0-Gy fractions were used, radiation necrosis developed in 5 patients (22%) in the CAIR group as a consequential late effect (CLE), but when fraction size was reduced to 1.8 Gy no more CLE occurred. Actuarial 5-year morbidity-free survival rate was similar for both treatments. Conclusions: Selected head-and-neck cancer patients could be treated very effectively with 7-days-a-week radiation schedule with no compromise of total dose and with slight 10% reduction of fraction dose (2 Gy-1.8 Gy), which article gives 1 week reduction of overall treatment time compared with standard 70 Gy in 35 fractions over 47-49 days. Although this report is based on the relatively small group of patients, its results have encouraged us to use CAIR fractionation in a standard radiation treatment for moderately advanced head-and-neck cancer patients

  16. Acute Toxicity Profile and Compliance to Accelerated Radiotherapy Plus Carbogen and Nicotinamide for Clinical Stage T2–4 Laryngeal Cancer: Results of a Phase III Randomized Trial

    Purpose: To report the acute toxicity profile and compliance from a randomized Phase III trial comparing accelerated radiotherapy (AR) with accelerated radiotherapy plus carbogen and nicotinamide (ARCON) in laryngeal cancer. Methods and Materials: From April 2001 to February 2008, 345 patients with cT2–4 squamous cell laryngeal cancer were randomized to AR (n = 174) and ARCON (n = 171). Acute toxicity was scored weekly until Week 8 and every 2–4 weeks thereafter. Compliance to carbogen and nicotinamide was reported. Results: Between both treatment arms (AR vs. ARCON) no statistically significant difference was observed for incidence of acute skin reactions (moist desquamation: 56% vs. 58%, p = 0.80), acute mucosal reactions (confluent mucositis: 79% vs. 85%, p = 0.14), and symptoms related to acute mucositis (severe pain on swallowing: 53% vs. 58%, p = 0.37; nasogastric tube feeding: 28% vs. 28%, p = 0.98; narcotic medicines required: 58% vs. 58%, p = 0.97). There was a statistically significant difference in median duration of confluent mucositis in favor of AR (2.0 vs 3.0 weeks, p = 0.01). There was full compliance with carbogen breathing and nicotinamide in 86% and 80% of the patients, with discontinuation in 6% and 12%, respectively. Adjustment of antiemesis prophylaxis was needed in 42% of patients. Conclusion: With the exception of a slight increase in median duration of acute confluent mucositis, the present data reveal a similar acute toxicity profile between both regimens and a good compliance with ARCON for clinical stage T2–4 laryngeal cancers. Treatment outcome and late morbidity will determine the real therapeutic benefit.

  17. Acute Toxicity Profile and Compliance to Accelerated Radiotherapy Plus Carbogen and Nicotinamide for Clinical Stage T2-4 Laryngeal Cancer: Results of a Phase III Randomized Trial

    Janssens, Geert O., E-mail: g.janssens@rther.umcn.nl [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Terhaard, Chris H. [Department of Radiation Oncology, University Medical Center Utrecht, Utrecht (Netherlands); Doornaert, Patricia A. [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Bijl, Hendrik P. [Department of Radiation Oncology, University Medical Center Groningen, Groningen (Netherlands); Ende, Piet van den [Department of Radiation Oncology, Maastricht University Medical Centre, Maastricht (Netherlands); Chin, Alim [Department of Clinical Oncology, Leiden University Medical Centre, Leiden (Netherlands); Pop, Lucas A.; Kaanders, Johannes H. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)

    2012-02-01

    Purpose: To report the acute toxicity profile and compliance from a randomized Phase III trial comparing accelerated radiotherapy (AR) with accelerated radiotherapy plus carbogen and nicotinamide (ARCON) in laryngeal cancer. Methods and Materials: From April 2001 to February 2008, 345 patients with cT2-4 squamous cell laryngeal cancer were randomized to AR (n = 174) and ARCON (n = 171). Acute toxicity was scored weekly until Week 8 and every 2-4 weeks thereafter. Compliance to carbogen and nicotinamide was reported. Results: Between both treatment arms (AR vs. ARCON) no statistically significant difference was observed for incidence of acute skin reactions (moist desquamation: 56% vs. 58%, p = 0.80), acute mucosal reactions (confluent mucositis: 79% vs. 85%, p = 0.14), and symptoms related to acute mucositis (severe pain on swallowing: 53% vs. 58%, p = 0.37; nasogastric tube feeding: 28% vs. 28%, p = 0.98; narcotic medicines required: 58% vs. 58%, p = 0.97). There was a statistically significant difference in median duration of confluent mucositis in favor of AR (2.0 vs 3.0 weeks, p = 0.01). There was full compliance with carbogen breathing and nicotinamide in 86% and 80% of the patients, with discontinuation in 6% and 12%, respectively. Adjustment of antiemesis prophylaxis was needed in 42% of patients. Conclusion: With the exception of a slight increase in median duration of acute confluent mucositis, the present data reveal a similar acute toxicity profile between both regimens and a good compliance with ARCON for clinical stage T2-4 laryngeal cancers. Treatment outcome and late morbidity will determine the real therapeutic benefit.

  18. Fractionated stereotactic radiotherapy for the treatment of vestibular schwannomas: combined experience of the Toronto-Sunnybrook Regional Cancer Centre and the Princess Margaret Hospital

    Purpose: To evaluate the efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) for vestibular schwannomas in patients treated at two university-affiliated hospitals. Methods and Materials: Thirty-nine patients were treated between April 1996 and September 2000. The median age was 56 years (range: 29-80), and median maximal tumor diameter was 20 mm (range: 9-40). A total of 11 patients had fifth and/or seventh cranial nerve dysfunction before irradiation; 2 patients had only facial weakness, 5 patients had only facial numbness, and 4 patients had both facial weakness and numbness. Thirty-three patients were treated with primary FSRT, and 6 patients were treated for recurrent or persistent disease after previous surgery. All patients were treated with 6-MV photons using a stereotactic system with a relocatable frame. The 39 patients received 50 Gy in 25 fractions over 5 weeks. Median follow-up was 21.8 months (range: 4.4-49.6). Results: Local control was achieved in 37 patients (95%). Two patients experienced deterioration of their symptoms at 3 and 20 months as a result of clinical progression in one case and tumor progression in the other and underwent surgery post FSRT. A total of 19/28 (67.9%) patients preserved serviceable hearing after FSRT. Deterioration of the facial and trigeminal nerves was observed in only 2 patients who were treated with surgery post FSRT. Conclusion: FSRT provided excellent tumor control with minimal morbidity and good hearing preservation in this cohort of patients. Longer follow-up is required to confirm long-term control rates

  19. Risk-adapted single or fractionated stereotactic high-precision radiotherapy in a pooled series of nonfunctioning pituitary adenomas. High local control and low toxicity

    The purpose of this work was to evaluate a prospectively initiated two-center protocol of risk-adapted single-fraction (SRS) or fractionated radiotherapy (SRT) in patients with nonsecretory pituitary adenomas (NSA). A total of 73 NSA patients (39 men/34 women) with a median age of 62 years were prospectively included in a treatment protocol of SRS [planning target volume (PTV) 2 mm to optic pathways = low risk] or SRT (PTV ≥ 4 ccm, ≤ 2 mm to optic pathways = high risk) in two Novalis registered centers. Mean tumor volume was 7.02 ccm (range 0.58-57.29 ccm). Based on the protocol guidelines, 5 patients were treated with SRS and 68 patients with SRT. Median follow-up (FU) reached 5 years with 5-year overall survival (OS) of 90.4 % (CI 80.2-95 %) and 5-year local control and progression-free survival rates of 100 % (CI 93.3-100 %) and 90.4 % (CI 80.2-95 %), respectively. A post-SRS/SRT new visual disorder occurred in 2 patients (2.7 %), a new oculomotor nerve palsy in one pre-irradiated patient, in 3 patients (4.1 %) a pre-existing visual disorder improved. New complete hypopituitarism occurred in 4 patients (13.8 %) and in 3 patients (25 %) with pre-existing partial hypopituitarism. Pituitary function in 26 % of patients retained normal. Patients with tumor shrinkage (65.75 %) had a significantly longer FU (p = 0.0093). Multivariate analysis confirmed correlation of new hypopituitarism with duration of FU (p = 0.008) and correlation of new hypopituitarism and tumor volume (p = 0.023). No significant influence factors for occurrence of visual disorders were found. Our SRS/SRT protocol proved to be safe and successful in terms of tumor control and protection of the visual system, especially for large tumors located close to optic pathways. (orig.)

  20. Salvage fractionated Stereotactic Radiotherapy (fSRT with or without chemotherapy and immunotherapy for recurrent Glioblastoma Multiforme: A single institution experience

    Shaakir eHasan

    2015-05-01

    Full Text Available Background: The current standard of care for salvage treatment of Glioblastoma Multiforme (GBM is gross total resection and adjuvant chemoradiation for operable patients. Limited evidence exists to suggest that any particular treatment modality improves survival for recurrent GBM, especially if inoperable. We report our experience with fractionated stereotactic radiotherapy (fSRT with and without chemo/immunotherapy, identifying prognostic factors associated with prolonged survival. Methods: From 2007 to 2014, 19 patients between 29 and 78 years old (median 55 with recurrent GBM following resection and chemoradiation for their initial tumor, received 18 – 35 Gy (median 25 in 3 – 5 fractions via Cyberknife fSRT. Clinical target volume (CTV ranged from 0.9 to 152 cc. Sixteen patients received adjuvant systemic therapy with bevacizumab (BEV, temozolomide (TMZ, anti-epidermal growth factor receptor (125I-mAb 425, or some combination thereof. Results: The median overall survival (OS from date of recurrence was 8 months (2.5 – 61 and 5.3 months (0.6 – 58 from the end of fSRT. The OS at 6 and 12 months was 47% and 32%, respectively. Three of 19 patients were alive at the time of this review at 20, 49 and 58 months from completion of fSRT. Hazard ratios for survival indicated that patients with a frontal lobe tumor, adjuvant treatment with either BEV or TMZ, time to first recurrence >16 months, CTV < 36 cc, Recursive Partitioning Analysis (RPA < 5, and ECOG (Eastern Cooperative Oncology Group performance status < 2 were all associated with improved survival (P <0.05. There was no evidence of radionecrosis for any patient.Conclusions: Radiation Therapy Oncology Group (RTOG 1205 will establish the role of reirradiation for recurrent GBM, however our study suggests that cyberknife with chemotherapy can be safely delivered, and is most effective in patients with smaller frontal lobe tumors, good performance status or long interval from diagnosis.

  1. Stereotactic hypofractionated accurate radiotherapy of the prostate (SHARP), 33.5 Gy in five fractions for localized disease: First clinical trial results

    Purpose: To evaluate the feasibility and toxicity of stereotactic hypofractionated accurate radiotherapy (SHARP) for localized prostate cancer. Methods and Materials: A Phase I/II trial of SHARP performed for localized prostate cancer using 33.5 Gy in 5 fractions, calculated to be biologically equivalent to 78 Gy in 2 Gy fractions (α/β ratio of 1.5 Gy). Noncoplanar conformal fields and daily stereotactic localization of implanted fiducials were used for treatment. Genitourinary (GU) and gastrointestinal (GI) toxicity were evaluated by American Urologic Association (AUA) score and Common Toxicity Criteria (CTC). Prostate-specific antigen (PSA) values and self-reported sexual function were recorded at specified follow-up intervals. Results: The study includes 40 patients. The median follow-up is 41 months (range, 21-60 months). Acute toxicity Grade 1-2 was 48.5% (GU) and 39% (GI); 1 acute Grade 3 GU toxicity. Late Grade 1-2 toxicity was 45% (GU) and 37% (GI). No late Grade 3 or higher toxicity was reported. Twenty-six patients reported potency before therapy; 6 (23%) have developed impotence. Median time to PSA nadir was 18 months with the majority of nadirs less than 1.0 ng/mL. The actuarial 48-month biochemical freedom from relapse is 70% for the American Society for Therapeutic Radiology and Oncology definition and 90% by the alternative nadir + 2 ng/mL failure definition. Conclusions: SHARP for localized prostate cancer is feasible with minimal acute or late toxicity. Dose escalation should be possible

  2. Incidence of severe capsular contracture following implant-based immediate breast reconstruction with or without postoperative chest wall radiotherapy using 40 Gray in 15 fractions

    Purpose: To determine the incidence of capsular contracture (CC) requiring revisional surgery in patients receiving postoperative radiotherapy (RT) or no RT following mastectomy and immediate breast reconstruction. Material and methods: One hundred and seventy-eight immediate breast reconstructions performed at the Cambridge Breast Unit between 1.1.2001 and 31.12.2005 were identified. RT was delivered using a standard UK scheme of 40 Gray in 15 fractions over 3 weeks. The influence of hormones and chemotherapy as well as postoperative RT on time to development of severe CC after implant-based reconstruction was explored in univariate and multivariate analysis. Results: One hundred and ten patients had implant-based reconstructions with a median follow-up of 51 months. In the RT group (41 patients), there were 8 patients with severe CC requiring revisional surgery, a crude rate of 19.5%, with actuarial rates of 0%, 5%, 5%, 21%, 30% and 30% at 1, 2, 3, 4, 5 and 6 years follow-up. In the unirradiated group, there were no cases of severe CC. This difference is highly significant (p < 0.001). Hormones and chemotherapy were not significantly associated with severe CC. Conclusions: This series showed a significantly higher rate of severe CC with postoperative RT. This finding has important clinical implications, when counselling patients for immediate breast reconstruction

  3. Procedure to measure the neutrons spectrum around a lineal accelerator for radiotherapy; Procedimiento para medir el espectro de los neutrones en torno a un acelerador lineal para radioterapia

    Vega C, H. R.; Hernandez D, V. M.; Letechipia de L, C. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Benites R, J. L. [Servicios de Salud de Nayarit, Centro Estatal de Cancerologia, Calzada de la Cruz 116 Sur, 63000 Tepic, Nayarit (Mexico); Salas L, M. A., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Agronomia, Apdo. Postal 336, 98000 Zacatecas (Mexico)

    2013-10-15

    An experimental procedure was developed, by means of Bonner spheres, to measure the neutrons spectrum around Linacs of medical use that only requires of a single shot of the accelerator; to this procedure we denominate Planetary or Isocentric method. One of the problems associated to the neutrons spectrum measurement in a radiotherapy room with lineal accelerator is because inside the room a mixed, intense and pulsed radiation field takes place affecting the detection systems based on active detector; this situation is solved using a passive detector. In the case of the Bonner spheres spectrometer the active detector has been substituted by activation detectors, trace detectors or thermoluminescent dosimeters. This spectrometer uses several spheres that are situated one at a time in the measurement point, this way to have the complete measurements group the accelerator should be operated, under the same conditions, so many times like spheres have the spectrometer, this activity can consume a long time and in occasions due to the work load of Linac to complicate the measurement process too. The procedure developed in this work consisted on to situate all the spectrometer spheres at the same time and to make the reading by means of a single shot, to be able to apply this procedure, is necessary that before the measurements two characteristics are evaluated: the cross-talking of the spheres and the symmetry conditions of the neutron field. This method has been applied to determine the photo-neutrons spectrum produced by a lineal accelerator of medical use Varian ix of 15 MV to 100 cm of the isocenter located to 5 cm of depth of a solid water mannequin of 30 x 30 x 15 cm. The spectrum was used to determine the total flow and the environmental dose equivalent. (Author)

  4. Large fraction radiotherapy plus misonidazole for treatment of advanced lung cancer: report of a phase I/II trial

    From August 1978 through December 1979, 51 patients with advanced non-oat cell carcinoma of the lung were enrolled in a Phase I/II trial sponsored by the Radiation Therapy Oncology Group (RTOG) employing misonidazole (a 2-nitroimidazole) as a hypoxic cell sensitizer and radiation. The purpose of this study was to test drug and radiation tolerance and to assess the short term efficacy of this unconventional treatment. Tumor doses of 600 rad were given twice weekly for three weeks for a total of 3600 rad, preceded four to six hours by misonidazole in a dose of 2 gm/m2 or 1.75 gm/m2, administered orally. Forty-nine patients were evaluable. Serious toxicity from this treatment was rare. Grade 2 or 3 peripheral neuro-toxicity occurred in eight of 24 patients (33%) with drug doses of 2 gm/m2 and in four of 26 patients (15%) who received 1.75 gm/m2. Grade 3 or 4 central nervous system toxicity occurred in two patients. Two patients developed serious late radiation complications: one patient had a transverse myelitis that appeared one year following delivery of 3600 rad to the spinal cord; a second patient developed a tracheoesophageal fistula and pericarditis eight months following treatment. Objective responses were reported in 67% of patients (complete in 18%); 70% of the patients died with a median survival time of nine months. Of 32 patients eligible for 12 month follow-up, 34% survived more than one year. Patterns of relapse after initial treatment and comparison with results from other RTOG trials using conventional fractionation are discussed

  5. Large fraction radiotherapy plus misonidazole for treatment of advanced lung cancer: report of a phase I/II trial

    Simpson, J.R. (Mallinckrodt Inst. of Radiology, St. Louis, MO); Perez, C.A.; Phillips, T.L.; Concannon, J.P.; Carella, R.J.

    1982-02-01

    From August 1978 through December 1979, 51 patients with advanced non-oat cell carcinoma of the lung were enrolled in a Phase I/II trial sponsored by the Radiation Therapy Oncology Group (RTOG) employing misonidazole (a 2-nitroimidazole) as a hypoxic cell sensitizer and radiation. The purpose of this study was to test drug and radiation tolerance and to assess the short term efficacy of this unconventional treatment. Tumor doses of 600 rad were given twice weekly for three weeks for a total of 3600 rad, preceded four to six hours by misonidazole in a dose of 2 gm/m/sup 2/ or 1.75 gm/m/sup 2/, administered orally. Forty-nine patients were evaluable. Serious toxicity from this treatment was rare. Grade 2 or 3 peripheral neuro-toxicity occurred in eight of 24 patients (33%) with drug doses of 2 gm/m/sup 2/ and in four of 26 patients (15%) who received 1.75 gm/m/sup 2/. Grade 3 or 4 central nervous system toxicity occurred in two patients. Two patients developed serious late radiation complications: one patient had a transverse myelitis that appeared one year following delivery of 3600 rad to the spinal cord; a second patient developed a tracheoesophageal fistula and pericarditis eight months following treatment. Objective responses were reported in 67% of patients (complete in 18%); 70% of the patients died with a median survival time of nine months. Of 32 patients eligible for 12 month follow-up, 34% survived more than one year. Patterns of relapse after initial treatment and comparison with results from other RTOG trials using conventional fractionation are discussed.

  6. Cancer of the larynx: the outcomes of conventionally fractionated radiotherapy in prospective and retrospective studies. Is the meaning of conventionality the same?

    Two studies on the radiotherapy of laryngeal cancer were completed at the Radiotherapy Department of the Cancer Center Warsaw at the end of 1999. One of them was a multicenter randomized clinical trial, and the second one - a retrospective study on patients treated between years 1989 and 1995. An opinion exists that the trial outcomes of the conventional arm correspond to the outcomes of everyday practice. The subject of the study was to evaluate this thesis, and to find out, whether the outcomes of prospective and retrospective studies following the same treatment protocol are comparable. Selection criteria were - age ≤75, WHO 0-1, T1, T2, T3, N0, M0 stage of glottic and supraglottic laryngeal cancer. The treatment was: 66 Gy/2 Gy/33 fraction/45 days. The prospective group had - 199 patients, and the retrospective group: 150 patients. The two groups were comparable according to the age, site, sex and mean hemoglobin level. There was a significant difference in T-stage and performance status between the two groups. Overall survival, local control and CR-response were analyzed. To eliminate the influence of the differences in T=stage and performance status, regression models were applied - Cox's for survival and local control, logit for CR-response endpoint. The protocol compliance (prospective, retrospective) was as follows - total dose: (88%, 49%), treatment time: (47%, 11%) respectively. Three-year survival for the prospective and the retrospective groups were 89% and 74%, respectively (p=0.035), CR-response rates were 96% and 75%, respectively (p<0.001). There were no significant differences in probability of local recurrence in CR patients. A better outcome of treatment was observed in the prospective study group. It is probably due to a certain 'over-selection' of patients for the prospective study and many deviations from the therapeutic protocol in the historical group. 'Conventional treatment' has the same meaning in the prospective and retrospective

  7. Studies on serum protein fractions of patients with maxillary sinus cancer undergoing a combination of radiotherapy and chemotherapy

    39 cases of maxillary sinus cancer were treated with combined intra-arterial infusion of bleomycin and external irradiation of 60Coγ-ray. Serum protein fractions in the sera of 39 cases of maxillary sinus cancer were examined through the radial immunodiffusion method, 1) before radiation treatment was given, 2) at the completion of radiation therapy and 3) after radiation therapy, ranging from 1 month to 36 months. The sera obtained from patients with maxillary sinus cancer before treatment had concentrations of: α1-acid glycoprotein (α1AG), α1-antitrypsin (α1AT), α1-chymotrypsin (α1X), haptoglobin (Hp), ceruloplasmin (Cp), β1C/A glycoprotein (C3), hemopexin (Hx), IgG and of IgA which were elevated compared with those of normal controls: However, the serum concentrations of: prealbumin (Prealb), albumin (Alb), transferrin (Tf), α2-macroglobulin (α2M), HS-glycoprotein (α2HS) and of IgM were reduced significantly. At the completion of radiation therapy, the concentrations of: Prealb, Tf, α1AG, α1X, Hx, C3, IgG, IgA and of IgM rose slightly as compared with levels before radiation therapy, and the concentrations of Alb, of α2HS and of α1AT were reduced. However, there was no significant difference between the former and the latter data. In patients who died within 12 months after treatment, the Prealb, Alb, Tf, α2HS, and IgM levels examined before radiation therapy were reduced and the α1AG level was elevated compared with those who had lived more than 13 months. The Prealb, Alb, Tf, and IgM levels, after radiation therapy were reduced; while the α1AG, Hp, and α1X levels were elevated. In patients who had lived more than 13 months, after treatment, concentrations of Prealb, of Alb, of Tf, of C3, of Hx, of IgG, of IgA and of IgM rose before and after radiation therapy, compared with those who died within 12 months. (author)

  8. Monte Carlo simulation for the production of neutrons inside the labyrinth function rooms radiotherapy in head rotation of medical linear accelerator use and energy operation

    This work consists of an analysis, through computer simulation using the Monte Carlo method, the production of neutrons generated by the interaction of the beam with useful materials that are heavy in head-accelerated linear medical use. We developed a computer model of the head of the linear accelerator Varian, where there was the ambient dose equivalent due to the neutrons H*(10)n the plane of the patient and the region of the labyrinth bunker for several angles of operating at energies of 10, 15, 18 MV. It was found that production of neutrons in the plane of the patient has direct dependency with increasing beam energy useful, since the labyrinth it appears that besides energy the operating angle also has a direct influence on the production of neutrons in the region of the labyrinth, consequently the door. Therefore, a survey of H*(10)n at various angles with different operating ranges of energy contributes to better planning studies concerning shielding doors in rooms radiotherapy. (author)

  9. Fractionated and single-dose radiotherapy for heterotopic bone formation in patients with spinal cord injury. A phase-I/II study

    Sautter-Bihl, M.L.; Hueltenschmidt, B.; Liebermeister, E. [Staedtisches Klinikum Karlsruhe (Germany). Klinik fuer Strahlentherapie und Nuklearmedizin; Nanassy, A. [Klinikum Karlsbad-Langensteinbach (Germany). Orthopaedie I

    2001-04-01

    Background: Heterotopic ossification occur in about 20% of patients with spinal cord injury and may seriously compromise the rehabilitation process. Aim of the present study was to evaluate if radiotherapy administered early in the course of the disease prevents the manifestation of heterotopic ossification and if in patients whose bone formations have been resected recurrence can be avoided. Patients and Methods: 52 patients (44 males, eight females, median age 33 years) and 75 joints were irradiated between December 1989 and March 2000. 49 patients (70 joints, 65 hips, three knees, one shoulder, one elbow) were evaluable. Median follow-up was 11 months. In 58 joints radiotherapy was performed as a primary treatment in the inflammatory phase of soft tissue swelling that precedes manifestation of heterotopic ossifications. Twelve joints were treated after resection of manifest heterotopic bone, two patients had primary and postoperative irradiation in different joints. The dose was 10 Gy in single fractions of 2-2,5 Gy in 34 joints and 7.5-20 Gy in six joints. >From July 1996 on, 30 joints received single-dose irradiation with 8 Gy. Results: 50/70 joints (71%) remained free from progression. This was the case for 47/65 (72%) hips, whereas in 18 hips (27%) the Brooker score increased for 1-2 grades and caused a moderate decrease of mobility in five joints. Out of the other five joints, two knees developed progression. No relevant side effects occurred. Conclusion: The present results suggest that radiotherapy is an effective local treatment option for spinal cord injured patients with heterotopic ossifications. (orig.) [German] Hintergrund: Heterotope Ossifikationen treten bei bis zu 20% von Patienten mit verletzungsbedingter Querschnittslaehmung auf und koennen die Rehabilitation erheblich erschweren. Ziel der vorliegenden Studie war zu evaluieren, ob durch eine primaer im Anfangsstadium der Erkrankung eingesetzte Strahlentherapie die Manifestation heterotoper

  10. A new concept of radiotherapy: space fractionation in proton therapy; Un nuevo concepto en radioterapia: fraccionamiento espacial en terapia con protones

    Prezado Alonso, Y.; Fois, G.

    2013-07-01

    In recent years several experiments with animals have shown that the combination of small field sizes and a spatial neighborhood of the dose of radiation therapy with synchrotron radiation techniques lead to a significant increase of the dose of tolerance of healthy tissues. The aim of this study is to evaluate the feasibility of a new form of radiotherapy: radiotherapy with proton minibeams. (Author)

  11. Intraoperative radiotherapy

    The potential benefit of intraoperative radiotherapy (IORT) was originally recognized years ago and has recently attracted renewed interest. Modern radiotherapeutic approaches may be more successful as a result of technical innovation, particularly in the use of electron beam accelerators. Preliminary studies, mainly uncontrolled and nonrandomized, have assessed the role of IORT for treatment of a variety of deep seated abdominal, retroperitoneal, and pelvic cancers. The results of some studies show much promise, but prospective trials are needed to scientifically validate these favorable initial observations. (Auth.)

  12. Risk-adapted single or fractionated stereotactic high-precision radiotherapy in a pooled series of nonfunctioning pituitary adenomas. High local control and low toxicity

    Bostroem, Jan Patrick [MediClin Robert Janker Clinic and MediClin MVZ Bonn, Department of Radiosurgery and Stereotactic Radiotherapy, Bonn (Germany); University Hospital of Bonn, Department of Neurosurgery, Bonn (Germany); Meyer, Almuth [HELIOS Klinikum Erfurt, Department of Endocrinology, Erfurt (Germany); Pintea, Bogdan [University Hospital of Bonn, Department of Neurosurgery, Bonn (Germany); Gerlach, Ruediger [HELIOS Klinikum Erfurt, Department of Neurosurgery, Erfurt (Germany); Surber, Gunnar; Hamm, Klaus [HELIOS Klinikum Erfurt, Department of Radiosurgery, Erfurt (Germany); Lammering, Guido [MediClin Robert Janker Clinic and MediClin MVZ Bonn, Department of Radiosurgery and Stereotactic Radiotherapy, Bonn (Germany); Heinrich-Heine-University of Duesseldorf, Department of Radiotherapy and Radiation Oncology, Duesseldorf (Germany)

    2014-12-15

    The purpose of this work was to evaluate a prospectively initiated two-center protocol of risk-adapted single-fraction (SRS) or fractionated radiotherapy (SRT) in patients with nonsecretory pituitary adenomas (NSA). A total of 73 NSA patients (39 men/34 women) with a median age of 62 years were prospectively included in a treatment protocol of SRS [planning target volume (PTV) < 4 ccm, > 2 mm to optic pathways = low risk] or SRT (PTV ≥ 4 ccm, ≤ 2 mm to optic pathways = high risk) in two Novalis registered centers. Mean tumor volume was 7.02 ccm (range 0.58-57.29 ccm). Based on the protocol guidelines, 5 patients were treated with SRS and 68 patients with SRT. Median follow-up (FU) reached 5 years with 5-year overall survival (OS) of 90.4 % (CI 80.2-95 %) and 5-year local control and progression-free survival rates of 100 % (CI 93.3-100 %) and 90.4 % (CI 80.2-95 %), respectively. A post-SRS/SRT new visual disorder occurred in 2 patients (2.7 %), a new oculomotor nerve palsy in one pre-irradiated patient, in 3 patients (4.1 %) a pre-existing visual disorder improved. New complete hypopituitarism occurred in 4 patients (13.8 %) and in 3 patients (25 %) with pre-existing partial hypopituitarism. Pituitary function in 26 % of patients retained normal. Patients with tumor shrinkage (65.75 %) had a significantly longer FU (p = 0.0093). Multivariate analysis confirmed correlation of new hypopituitarism with duration of FU (p = 0.008) and correlation of new hypopituitarism and tumor volume (p = 0.023). No significant influence factors for occurrence of visual disorders were found. Our SRS/SRT protocol proved to be safe and successful in terms of tumor control and protection of the visual system, especially for large tumors located close to optic pathways. (orig.) [German] Evaluation eines prospektiv angelegten Behandlungsprotokolls einer risikoadaptierten Radiochirurgie (SRS) oder stereotaktischen Radiotherapie (SRT) von Patienten mit hormoninaktiven Hypophysenadenomen

  13. Poster — Thur Eve — 28: Enabling trajectory-based radiotherapy on a TrueBeam accelerator with the Eclipse treatment planning system

    Mullins, J; Asiev, K; DeBlois, F; Morcos, M; Seuntjens, J; Syme, A [Department of Oncology, McGill University (Canada)

    2014-08-15

    The TrueBeam linear accelerator platform has a developer's mode which permits the user dynamic control over many of the machine's mechanical and radiation systems. Using this research tool, synchronous couch and gantry motion can be programmed to simulate isocentric treatment with a shortened SAD, with benefits such as smaller projected MLC leaf widths and an increased dose rate. In this work, water tank measurements were used to commission a virtual linear accelerator with an 85 cm SAD in Eclipse, from which several arc-based radiotherapy treatments were generated, including an inverse optimized VMAT delivery. For each plan, the pertinent treatment delivery information was extracted from control points specified in the Eclipse-exported DICOM files using the pydicom package in Python, allowing construction of an XML control file. The dimensions of the jaws and MLC positions, defined for an 85 cm SAD in Eclipse, were scaled for delivery on a conventional SAD linear accelerator, and translational couch motion was added as a function of gantry angle to simulate delivery at 85 cm SAD. Ionization chamber and Gafchromic film measurements were used to compare the radiation delivery to dose calculations in Eclipse. With the exception of the VMAT delivery, ionization chamber measurements agreed within 3.3% of the Eclipse calculations. For the VMAT delivery, the ionization chamber was located in an inhomogeneous region, but gamma evaluation of the Gafchromic film plane resulted in a 94.5% passing rate using criteria of 3 mm/3%. The results indicate that Eclipse calculation infrastructure can be used.

  14. Poster — Thur Eve — 28: Enabling trajectory-based radiotherapy on a TrueBeam accelerator with the Eclipse treatment planning system

    The TrueBeam linear accelerator platform has a developer's mode which permits the user dynamic control over many of the machine's mechanical and radiation systems. Using this research tool, synchronous couch and gantry motion can be programmed to simulate isocentric treatment with a shortened SAD, with benefits such as smaller projected MLC leaf widths and an increased dose rate. In this work, water tank measurements were used to commission a virtual linear accelerator with an 85 cm SAD in Eclipse, from which several arc-based radiotherapy treatments were generated, including an inverse optimized VMAT delivery. For each plan, the pertinent treatment delivery information was extracted from control points specified in the Eclipse-exported DICOM files using the pydicom package in Python, allowing construction of an XML control file. The dimensions of the jaws and MLC positions, defined for an 85 cm SAD in Eclipse, were scaled for delivery on a conventional SAD linear accelerator, and translational couch motion was added as a function of gantry angle to simulate delivery at 85 cm SAD. Ionization chamber and Gafchromic film measurements were used to compare the radiation delivery to dose calculations in Eclipse. With the exception of the VMAT delivery, ionization chamber measurements agreed within 3.3% of the Eclipse calculations. For the VMAT delivery, the ionization chamber was located in an inhomogeneous region, but gamma evaluation of the Gafchromic film plane resulted in a 94.5% passing rate using criteria of 3 mm/3%. The results indicate that Eclipse calculation infrastructure can be used

  15. Analysis of inter-fraction setup errors and organ motion by daily kilovoltage cone beam computed tomography in intensity modulated radiotherapy of prostate cancer

    Intensity-modulated radiotherapy (IMRT) enables a better conformality to the target while sparing the surrounding normal tissues and potentially allows to increase the dose to the target, if this is precisely and accurately determined. The goal of this work is to determine inter-fraction setup errors and prostate motion in IMRT for localized prostate cancer, guided by daily kilovoltage cone beam computed tomography (kVCBCT). Systematic and random components of the shifts were retrospectively evaluated by comparing two matching modalities (automatic bone and manual soft-tissue) between each of the 641 daily kVCBCTs (18 patients) and the planning kVCT. A simulated Adaptive Radiation Therapy (ART) protocol using the average of the first 5 kVCBCTs was tested by non-parametric bootstrapping procedure. Shifts were < 1 mm in left-right (LR) and in supero-inferior (SI) direction. In antero-posterior (AP) direction systematic prostate motion (2.7 ± 0.7 mm) gave the major contribution to the variability of results; the averages of the absolute total shifts were significantly larger in anterior (6.3 ± 0.2 mm) than in posterior (3.9 mm ± 0.2 mm) direction. The ART protocol would reduce margins in LR, SI and anterior but not in posterior direction. The online soft-tissue correction based on daily kVCBCT during IMRT of prostate cancer is fast and efficient. The large random movements of prostate respect to bony anatomy, especially in the AP direction, where anisotropic margins are needed, suggest that daily kVCBCT is at the present time preferable for high dose and high gradients IMRT prostate treatments

  16. Long-term outcome after highly advanced single-dose or fractionated radiotherapy in patients with vestibular schwannomas – Pooled results from 3 large German centers

    Purpose: To evaluate long-term clinical outcome and determine prognostic factors for local-control, hearing preservation and cranial nerve toxicity in 449 patients treated for 451 vestibular schwannomas (VS) with radiosurgery (n = 169; 38%) or fractionated stereotactic radiotherapy (FSRT; n = 291; 62%). Methods and materials: 245 patients were male (55%), and 204 were female (45%). Median age was 60 years (range 17–88 years). Median tumor diameter was 15 mm. For FSRT, a median dose of 57.6 Gy in median single doses of 1.8 Gy was applied. For SRS, median dose was 13 Gy. The median follow-up time was 67 months. Results: Local control was 97% at 36 months, 95% at 60 months, and 94% at 120 months with no difference between FSRT and SRS (p = 0.39). “Useful hearing” was present 46%. After RT, “useful hearing” was preserved in 85% of the patients. Loss of useful hearing was observed in the FSRT group in 14%, and in the SRS group in 16% of the patients. For patients treated with SRS ⩽13 Gy, useful hearing deterioration was 13%. For trigeminal and facial nerve toxicity, there was no difference between FSRT and SRS. Conclusion: Supported by this large multicentric series, both SRS and FSRT can be recommended for the treatment of VS. SRS application is limited by tumor size, and is associated with a steep dose–response-curve. When chosen diligently based on tumor volume, pre-treatment characteristics and volume-dependent dose-prescription in SRS (⩽13 Gy), both treatments may be considered equally effective

  17. NSCLC: primary tumor size - radiation dose-related accelerated, twice daily radiotherapy by target splitting, preceded by 2 cycles of chemotherapy. First results of a prospective study

    Ensuing a phase I trial of accelerated, twice daily high dose radiotherapy showing good tolerability, a prospective study relating primary tumor size with radiation dose in non-operated patients with non-small cell lung cancer (NSCLC) was started. From 01/2004 until 12/2006 79 patients with 81 histologically/cytologically proven NSCLC tumors were treated, representing 94% of all referred non-operated NSCLC patients in stage Mo, malignant pleural effusions excluded. For the majority of patients the conformal target splitting technique has been employed. The target is split into a cranial and a caudal part; beam arrangements in the two parts are completely independent. In order to reduce internal margins slow planning CTs (4 sec./slice) were used, patients freely breathing, 7 mm margins from gross tumor volume to planning target volume. We formed 4 groups with primary tumor sizes (mean number of 3 perpendicular diameters) 6,0 cm (11/41/22/7 patients, respectively); tumor doses of 73,8, 79,2, 84,6 and 90,0 Gy (ICRU) were applied to the primary tumors of the patients in the respective groups. Single dose 1,8 Gy; twice daily, interval 11 h; 5 days/week; duration 33 days median (range 29-42). Macroscopically involved nodes 61,2 Gy median (range 54,0-75,6 Gy), nodes electively 45,0 Gy (to volume about 6 cm cranial to apparently involved nodes). In 62 patients chemotherapy before radiotherapy was given, 2 cycles median, generally a cisplatin or carboplatin containing doublet; no concurrent chemotherapy. Median follow-up of all patients 16,7 months, of patients alive 19,3 months. Until now 10 local failures (0/11, 3/41, 5/22, 2/7 in the respective groups) and 2 regional failures occured, resulting in an actuarial local and regional tumor control of 80,1% and 96% at 2 years, respectively. Local failures relate to the primary tumor site, regional failures to the regional node sites. Overall actuarial 1-, 2-year survival rate for all patients: 76%, 56%, respectively, median 26

  18. Concomitant boost radiotherapy in oropharynx carcinomas

    Fifty-five patients with resectable and unresectable oropharynx carcinomas were treated with concomitant boost radiotherapy. Forty-two of the patients (76%) had stages III-IV disease. Although none of the patients had undergone major surgery to the primary tumor, 11 had neck dissections prior to radiotherapy, and 19 (35%) received chemotherapy. The planned total tumor dose was 69.9 Gy, delivered over 5.5 weeks. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 13 fractions of 1.5 Gy each, as a second daily fraction in a progressively accelerated schedule; the prescribed dose outside the boost volume thus was 50.4 Gy. Median follow-up for surviving patients was 31.5 months (range: 16-65 months). All patients but one completed the planned radiotherapy schedule. According to the RTOG scoring system, 48 patients (88%) presented with grades 3-4 acute toxicity. The rate of grades 3-4 late complications was 12%. At three years the actuarial locoregional control rate was 69.5% and overall survival was 60%. We conclude that this concomitant boost schedule is feasible and does not seem to be associated with an excess risk of late complications. Acute toxicity was higher in association with chemotherapy, but remained manageable. Although the oncological results appear encouraging, evaluation of the efficacy of concomitant boost schedules compared with conventionally fractionated irradiation with or without concomitant chemotherapy requires prospective randomized trials. (orig.)

  19. Concomitant boost radiotherapy in oropharynx carcinomas

    Bieri, S.; Allal, A.S.; Kurtz, J.M. [Ospedale San Giovanni, Bellinzona (Switzerland). Dept. of Radiation Oncology; Dulguerov, P.; Lehmann, W. [Geneva Univ. Hospital (Switzerland). Div. of Head and Neck Surgery

    1998-12-31

    Fifty-five patients with resectable and unresectable oropharynx carcinomas were treated with concomitant boost radiotherapy. Forty-two of the patients (76%) had stages III-IV disease. Although none of the patients had undergone major surgery to the primary tumor, 11 had neck dissections prior to radiotherapy, and 19 (35%) received chemotherapy. The planned total tumor dose was 69.9 Gy, delivered over 5.5 weeks. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 13 fractions of 1.5 Gy each, as a second daily fraction in a progressively accelerated schedule; the prescribed dose outside the boost volume thus was 50.4 Gy. Median follow-up for surviving patients was 31.5 months (range: 16-65 months). All patients but one completed the planned radiotherapy schedule. According to the RTOG scoring system, 48 patients (88%) presented with grades 3-4 acute toxicity. The rate of grades 3-4 late complications was 12%. At three years the actuarial locoregional control rate was 69.5% and overall survival was 60%. We conclude that this concomitant boost schedule is feasible and does not seem to be associated with an excess risk of late complications. Acute toxicity was higher in association with chemotherapy, but remained manageable. Although the oncological results appear encouraging, evaluation of the efficacy of concomitant boost schedules compared with conventionally fractionated irradiation with or without concomitant chemotherapy requires prospective randomized trials. (orig.)

  20. Accelerated high-dose radiotherapy alone or combined with either concomitant or sequential chemotherapy; treatments of choice in patients with Non-Small Cell Lung Cancer

    Results of high-dose chemo-radiotherapy (CRT), using the treatment schedules of EORTC study 08972/22973 or radiotherapy (RT) alone were analyzed among all patients (pts) with Non Small Cell Lung Cancer (NSCLC) treated with curative intent in our department from 1995–2004. Included are 131 pts with medically inoperable or with irresectable NSCLC (TNM stage I:15 pts, IIB:15 pts, IIIA:57 pts, IIIB:43 pts, X:1 pt). Group I: Concomitant CRT: 66 Gy/2.75 Gy/24 fractions (fx)/33 days combined with daily administration of cisplatin 6 mg/m2: 56 pts (standard). Group II: Sequential CRT: two courses of a 21-day schedule of chemotherapy (gemcitabin 1250 mg/m2 d1, cisplatin 75 mg/m2 d2) followed by 66 Gy/2.75 Gy/24 fx/33 days without daily cisplatin: 26 pts. Group III: RT: 66 Gy/2.75 Gy/24 fx/33 days or 60 Gy/3 Gy/20 fx/26 days: 49 pts. The 1, 2, and 5 year actuarial overall survival (OS) were 46%, 24%, and 15%, respectively. At multivariate analysis the only factor with a significantly positive influence on OS was treatment with chemo-radiation (P = 0.024) (1-, 2-, and 5-yr OS 56%, 30% and 22% respectively). The incidence of local recurrence was 36%, the incidence of distant metastases 46%. Late complications grade 3 were seen in 21 pts and grade 4 in 4 patients. One patient had a lethal complication (oesophageal). For 32 patients insufficient data were available to assess late complications. In this study we were able to reproduce the results of EORTC trial 08972/22973 in a non-selected patient population outside of the setting of a randomised trial. Radiotherapy (66 Gy/24 fx/33 days) combined with either concomitant daily low dose cisplatin or with two neo-adjuvant courses of gemcitabin and cisplatin are effective treatments for patients with locally advanced Non-Small Cell Lung Cancer. The concomitant schedule is also suitable for elderly people with co-morbidity

  1. Dosimetric comparison between three dimensional conformal radiotherapy, tomo-therapy and treatment by Cyberknife: about one case of a ponto cerebellar meningioma; Comparaison dosimetrique entre radiotherapie conformationnelle tridimensionnelle, tomotherapie et traitement par cyberknife: a propos d'un cas de meningiome de l'angle pontocerebelleux

    Vasseur, F.; Rezvoy, N.; Lacornerie, T.; Lartigau, E. [Centre Oscar-Lambret, Dept. Universitaire de Radiotherapie, 59 - Lille (France)

    2009-10-15

    In order to illustrate the evolution of techniques in radiotherapy we compare the dose distributions calculated for the exclusive treatment of a ponto-cerebellar angle meningioma by a linear accelerator (clinac 2100) by helical irradiation and by cyberknife in radiosurgery mode and in fractionated mode. In conclusion: according to our first results, the tomo-therapy or the fractionated stereotactic radiotherapy appear as the treatments conjugating the advantages of stereotactic radiotherapy ( conformation of the dose to the target volume) and the fractionated radiotherapy ( protection of sane tissues by the fractionation). This study highlights the saving of sane tissues that allows these techniques. this better tolerance is to be evaluated. If it was confirmed, an increasing of the dose prescribed on the target volume could be considered. (N.C.)

  2. Future directions for radiotherapy: Gray or Blue perspective?

    Over the past 20 years radiobiological and clinical rationale for altered radiotherapy were defined. Better understanding of the importance of dose per fraction, ovetrall treatment time, time interval between fractions, and tumor and normal tissue repair mechanisms have contributed to the studies on accelerated (AF) and hyperfractionated (HF) radiotherapy. The results of these studies lead to development of combined AF-HF schedules. Among numerous pilot and randomized studies the only few were recognized as important. Hyperfractionation was found to be advantageous in advanced oropharyngeal cancers, and CHART increased therapeutic gain in advanced laryngeal cancer. Accelerated hyperfractionation (AF-FH) improves local control and/or permits a lower total dose for the same rate of control. Better tumor control has always involved increased severity of acute mucosal reactions. The results of clinical trials which improved effectiveness of radiotherapy are discussed. A variety of physical parameters used in altered fractionation makes difficult the comparison of biological effect of different fractionation regimens based on doses in Grays. A new concept of Biological Units of effectiveness - BLUE, proposed by Withers is presented. It is interesting complex system of biological dosimetry which might supplement the Gray doses. Basic assumption of this concept and practical example are presented. (author)

  3. Experience of micromultileaf collimator linear accelerator based single fraction stereotactic radiosurgery: Tumor dose inhomogeneity, conformity, and dose fall off

    Hong, Linda X.; Garg, Madhur; Lasala, Patrick; Kim, Mimi; Mah, Dennis; Chen, Chin-Cheng; Yaparpalvi, Ravindra; Mynampati, Dinesh; Kuo, Hsiang-Chi; Guha, Chandan; Kalnicki, Shalom [Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Neurosurgery, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Epidemiology and Population Health, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States)

    2011-03-15

    Purpose: Sharp dose fall off outside a tumor is essential for high dose single fraction stereotactic radiosurgery (SRS) plans. This study explores the relationship among tumor dose inhomogeneity, conformity, and dose fall off in normal tissues for micromultileaf collimator (mMLC) linear accelerator (LINAC) based cranial SRS plans. Methods: Between January 2007 and July 2009, 65 patients with single cranial lesions were treated with LINAC-based SRS. Among them, tumors had maximum diameters {<=}20 mm: 31; between 20 and 30 mm: 21; and >30 mm: 13. All patients were treated with 6 MV photons on a Trilogy linear accelerator (Varian Medical Systems, Palo Alto, CA) with a tertiary m3 high-resolution mMLC (Brainlab, Feldkirchen, Germany), using either noncoplanar conformal fixed fields or dynamic conformal arcs. The authors also created retrospective study plans with identical beam arrangement as the treated plan but with different tumor dose inhomogeneity by varying the beam margins around the planning target volume (PTV). All retrospective study plans were normalized so that the minimum PTV dose was the prescription dose (PD). Isocenter dose, mean PTV dose, RTOG conformity index (CI), RTOG homogeneity index (HI), dose gradient index R{sub 50}-R{sub 100} (defined as the difference between equivalent sphere radius of 50% isodose volume and prescription isodose volume), and normal tissue volume (as a ratio to PTV volume) receiving 50% prescription dose (NTV{sub 50}) were calculated. Results: HI was inversely related to the beam margins around the PTV. CI had a ''V'' shaped relationship with HI, reaching a minimum when HI was approximately 1.3. Isocenter dose and mean PTV dose (as percentage of PD) increased linearly with HI. R{sub 50}-R{sub 100} and NTV{sub 50} initially declined with HI and then reached a plateau when HI was approximately 1.3. These trends also held when tumors were grouped according to their maximum diameters. The smallest tumor group

  4. Experience of micromultileaf collimator linear accelerator based single fraction stereotactic radiosurgery: Tumor dose inhomogeneity, conformity, and dose fall off

    Purpose: Sharp dose fall off outside a tumor is essential for high dose single fraction stereotactic radiosurgery (SRS) plans. This study explores the relationship among tumor dose inhomogeneity, conformity, and dose fall off in normal tissues for micromultileaf collimator (mMLC) linear accelerator (LINAC) based cranial SRS plans. Methods: Between January 2007 and July 2009, 65 patients with single cranial lesions were treated with LINAC-based SRS. Among them, tumors had maximum diameters ≤20 mm: 31; between 20 and 30 mm: 21; and >30 mm: 13. All patients were treated with 6 MV photons on a Trilogy linear accelerator (Varian Medical Systems, Palo Alto, CA) with a tertiary m3 high-resolution mMLC (Brainlab, Feldkirchen, Germany), using either noncoplanar conformal fixed fields or dynamic conformal arcs. The authors also created retrospective study plans with identical beam arrangement as the treated plan but with different tumor dose inhomogeneity by varying the beam margins around the planning target volume (PTV). All retrospective study plans were normalized so that the minimum PTV dose was the prescription dose (PD). Isocenter dose, mean PTV dose, RTOG conformity index (CI), RTOG homogeneity index (HI), dose gradient index R50-R100 (defined as the difference between equivalent sphere radius of 50% isodose volume and prescription isodose volume), and normal tissue volume (as a ratio to PTV volume) receiving 50% prescription dose (NTV50) were calculated. Results: HI was inversely related to the beam margins around the PTV. CI had a ''V'' shaped relationship with HI, reaching a minimum when HI was approximately 1.3. Isocenter dose and mean PTV dose (as percentage of PD) increased linearly with HI. R50-R100 and NTV50 initially declined with HI and then reached a plateau when HI was approximately 1.3. These trends also held when tumors were grouped according to their maximum diameters. The smallest tumor group (maximum diameters ≤20 mm) had the most HI dependence

  5. Prospective phase II study of preoperative short-course radiotherapy for rectal cancer with twice daily fractions of 2.9 Gy to a total dose of 29 Gy - Long-term results

    To evaluate clinical outcome after preoperative short-course radiotherapy for rectal cancer with twice daily fractions of 2.9 Gy to a total dose of 29 Gy and adjuvant chemotherapy for pathological stage UICC ≥ II. 118 patients (median age 64 years; male : female ratio 2.5 : 1) with pathological proven rectal cancer (clinical stage II 50%, III 41.5%, IV 8.5%) were treated preoperatively with twice daily radiotherapy of 2.9 Gy single fraction dose to a total dose of 29 Gy; surgery was performed immediately in the following week with total mesorectal excision (TME). Adjuvant 5-FU based chemotherapy was planned for pathological stage UICC ≥ II. After low anterior resection (70%) and abdominoperineal resection (30%), pathology showed stage UICC I (27.1%), II (25.4%), III (37.3%) and IV (9.3%). Perioperative mortality was 3.4% and perioperative complications were observed in 22.8% of the patients. Adjuvant chemotherapy was given in 75.3% of patients with pathological stage UICC ≥ II. After median follow-up of 46 months, five-year overall survival was 67%, cancer-specific survival 76%, local control 92% and freedom from systemic progression 75%. Late toxicity > grade II was observed in 11% of the patients. Preoperative short-course radiotherapy, total mesorectal excision and adjuvant chemotherapy for pathological stage UICC ≥ II achieved excellent local control and favorable survival

  6. Determination of the neutron spectra in the treatment room of a linear accelerator for radiotherapy; Determinacion de los espectros de neutrones en la sala de tratamiento de un acelerador lineal para radioterapia

    Vega C, H.R. [Universidad Autonoma de Zacatecas, Cuerpo Academico de Radiobiologia, A.P. 336, 98000 Zacatecas (Mexico); Barquero, R. [Hospital Universitario Rio Hortega, Valladolid (Spain); Mendez, R.; Iniguez, M.P. [Depto. de Fisica Teorica, Atomica, Molecular y Nuclear, Universidad de Valladolid, 47011 Valladolid (Spain)

    2003-07-01

    By means of a series of measures and Monte Carlo calculations the dosimetric characteristics of the photoneutrons have been determined that take place in volume to a linear accelerator of radiotherapy of 18 MV, LINAC, mark Siemens Mevatron model. The measures were carried out with thermoluminescent dosemeters TLD 600 and TLD 700 that were naked exposed and confined with cover of Cd and Sn, inside a sphere of paraffin and inside spheres Bonner. (Author)

  7. Accelerated repopulation as a cause of radiation treatment failure in non-small cell lung cancer: review of current data and future clinical strategies.

    Yom, Sue S

    2015-04-01

    Despite convincing evidence that the principles of accelerated repopulation would open up additional therapeutic opportunities in the treatment of advanced-stage non-small cell lung cancer, this strategy has been generally underexplored. The implementation of accelerated radiotherapy schedules has been hampered by logistical barriers, concerns about acute toxicity, and the prioritization of integrating concurrent chemotherapy into the standard treatment platform. At present, it is unclear to what extent accelerated fractionation will influence future treatment paradigms in non-small cell lung cancer, although technical advances in radiotherapy, allowing higher dose delivery with reduced toxicity, could permit the development of more convenient and tolerable forms of accelerated schedules. PMID:25771413

  8. Clinical Experiences With Onboard Imager KV Images for Linear Accelerator-Based Stereotactic Radiosurgery and Radiotherapy Setup

    Purpose: To report our clinical experiences with on-board imager (OBI) kV image verification for cranial stereotactic radiosurgery (SRS) and radiotherapy (SRT) treatments. Methods and Materials: Between January 2007 and May 2008, 42 patients (57 lesions) were treated with SRS with head frame immobilization and 13 patients (14 lesions) were treated with SRT with face mask immobilization at our institution. No margin was added to the gross tumor for SRS patients, and a 3-mm three-dimensional margin was added to the gross tumor to create the planning target volume for SRT patients. After localizing the patient with stereotactic target positioner (TaPo), orthogonal kV images using OBI were taken and fused to planning digital reconstructed radiographs. Suggested couch shifts in vertical, longitudinal, and lateral directions were recorded. kV images were also taken immediately after treatment for 21 SRS patients and on a weekly basis for 6 SRT patients to assess any intrafraction changes. Results: For SRS patients, 57 pretreatment kV images were evaluated and the suggested shifts were all within 1 mm in any direction (i.e., within the accuracy of image fusion). For SRT patients, the suggested shifts were out of the 3-mm tolerance for 31 of 309 setups. Intrafraction motions were detected in 3 SRT patients. Conclusions: kV imaging provided a useful tool for SRS or SRT setups. For SRS setup with head frame, it provides radiographic confirmation of localization using the stereotactic target positioner. For SRT with mask, a 3-mm margin is adequate and feasible for routine setup when TaPo is combined with kV imaging

  9. Be aware of neutrons outside short mazes from 10-mv linear accelerators x-rays in radiotherapy facilities

    During the radiation survey of a reinstalled 10-MV linear accelerator in an old radiation treatment facility, high dose rates of neutrons were observed. The area outside the maze entrance is used as a waiting room where patients, their relatives and staff other than those involved in the actual treatment can freely pass. High fluence rates of neutrons would cause an unnecessary high effective dose to the staff working in the vicinity of such a system, and it can be several orders higher than the doses received due to X-rays at the same location. However, the common knowledge appears to have been that the effect of neutrons at 10-MV X-ray linear accelerator facilities is negligible and shielding calculations models seldom mention neutrons for this operating energy level. Although data are scarce, reports regarding this phenomenon are now emerging. For the future, it is advocated that contributions from neutrons are considered already during the planning stage of new or modified facilities aimed for