Late course accelerated hyperfractionated radiotherapy of nasopharyngeal carcinoma (LCAF)

International Nuclear Information System (INIS)

He Xiayun; Liu Taifu; He Shaoqin; Huan Sulan; Pan Ziqiang

2007-01-01

Background and purpose: To study the efficacy of late course accelerated fractionated (LCAF) radiotherapy in the treatment of nasopharyngeal carcinoma (NPC). The end-points were local control, radiation-induced complications, and factors influencing survival. Patients and methods: Between December 1995 and April 1998, 178 consecutive NPC patients were admitted for radiation treatment. The radiation beam used was 60 Co γ or 6 MV X rays. 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 h, 5 days per week to a total dose of 48 Gy/40 fractions, over a period of 4 weeks. For the last third of the treatment, i.e., beginning the 5th week of treatment, an accelerated hyperfractionated schedule was carried out. The dose per fraction was increased to 1.5 Gy, 2 fractions per day with an interval of ≥6 h, 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 cases, Grade 1 in 43 cases, Grade 2 in 78 cases, Grade 3 in 52 cases, and Grade 4 in 3 cases. Local control rate: the 5 year nasopharyngeal local control rate was 87.7%, and the cervical lymph nodes local control rate was 85.7%. The 5-year distant metastasis rate was 26.1%, and 5 year survivals were 67.9%, 16 (9%) patients had radiation-induced cranial nerve palsy, 7(4%) patients had temporal lobe or brainstem damage. Conclusions: With this treatment schedule, patients' tolerance was good, local control and 5 year survivals were better than conventional fractionation schedules, and radiation-related late complications did not increase, as 5-year survival rates of conventional fractionation radiotherapy were only 58%. Randomized clinical trials are being carried out to further confirm the efficacy of LCAF for nasopharyngeal carcinoma

Quality assurance in fractionated stereotactic radiotherapy

International Nuclear Information System (INIS)

Warrington, A.P.; Laing, R.W.; Brada, M.

1994-01-01

The recent development of fractionated stereotactic radiotherapy (SRT), which utilises the relocatable Gill-Thomas-Cosman frame (GTC 'repeat localiser'), requires comprehensive quality assurance (QA). This paper focuses on those QA procedures particularly relevant to fractionated SRT treatments, and which have been derived from the technique used at the Royal Marsden Hospital. They primarily relate to the following: (i) GTC frame fitting, initially in the mould room, and then at each imaging session and treatment fraction; (ii) checking of the linear accelerator beam geometry and alignment lasers; and (iii) setting up of the patient for each fraction of treatment. The precision of the fractionated technique therefore depends on monitoring the GTC frame relocation at each fitting, checking the accuracy of the radiation isocentre of the treatment unit, its coincidence with the patient alignment lasers and the adjustments required to set the patient up accurately. The results of our quality control checks show that setting up to a mean radiation isocentre using precisely set-up alignment lasers can be achievable to within 1 mm accuracy. When this is combined with a mean GTC frame relocatability of 1 mm on the patient, a 2-mm allowance between the prescribed isodose surface and the defined target volume is a realistic safety margin for this technique

Role of radiotherapy fractionation in head and neck cancers (MARCH)

DEFF Research Database (Denmark)

Lacas, Benjamin; Bourhis, Jean; Overgaard, Jens

2017-01-01

BACKGROUND: The Meta-Analysis of Radiotherapy in squamous cell Carcinomas of Head and neck (MARCH) showed that altered fractionation radiotherapy is associated with improved overall and progression-free survival compared with conventional radiotherapy, with hyperfractionated radiotherapy showing...... the greatest benefit. This update aims to confirm and explain the superiority of hyperfractionated radiotherapy over other altered fractionation radiotherapy regimens and to assess the benefit of altered fractionation within the context of concomitant chemotherapy with the inclusion of new trials. METHODS......: For this updated meta-analysis, we searched bibliography databases, trials registries, and meeting proceedings for published or unpublished randomised trials done between Jan 1, 2009, and July 15, 2015, comparing primary or postoperative conventional fractionation radiotherapy versus altered fractionation...

Second Study of Hyper-Fractionated Radiotherapy

Directory of Open Access Journals (Sweden)

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.

ACCELERATED REGIMENS OF ADJUVANT RADIOTHERAPY IN THE TREATMENT OF BREAST CANCER

Directory of Open Access Journals (Sweden)

G. V. Afonin

2017-01-01

Full Text Available Treatment of breast cancer (BC is a complex multidisciplinary problem. Often, radiation therapy is an obligatory component of treatment of breast cancer patients. Numerous large randomized trials have proved the efficacy of adjuvant radiotherapy in both the standard fractionation regimen in a single focal dose of 2 Gy to a total focal dose of 50 Gy for 25 fractions and in modes of hypofractionation using radiation exposure at a larger daily dose with a reduction in the total treatment time. The presented review summarizes the data of the largest studies on the modes of hypofractionation of postoperative radiotherapy for breast cancer. Most of the studies comparing the standard mode of fractionation of postoperative radiotherapy with the modes of hypofractionation showed comparable results for the main oncological parameters with similar tolerability, frequency of complications and good cosmetic results. It also shows the economic feasibility of applying accelerated regimes in everyday practice. Despite the fact that radiotherapy in the mode of hypofractionation has already become the standard of treatment and is recommended for use by the largest European and American cancer associations, indications for its conduct, the criteria for selection in the studies and the range of recommended single focal doses differ. The obtained results do not give an opportunity to confidently judge the advantage of one or another regime. It is necessary to determine the factors of a favorable and unfavorable prognosis, to clarify the indications for the use of various radiotherapy techniques. Therefore, questions about the optimal mode of hypo-fractionation of adjuvant radiotherapy, the timing of its initiation and the criteria for selecting patients for this type of therapy as part of the comprehensive treatment of breast cancer have not yet been fully resolved. Also open is the choice of optimal single and total doses of radiation, its combination with drug

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

International Nuclear Information System (INIS)

Al-Wassia, Rolina; Dal Pra, Alan; Shun, Kitty; Shaban, Ahmed; Corriveau, Christine; Edelstein, Chaim; Deschenes, Jean; Ruo, Russel; Patrocinio, Horacio; Cury, Fabio L.B.; DeBlois, François; Shenouda, George

2011-01-01

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

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

International Nuclear Information System (INIS)

Qayyum, M

2014-01-01

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

Patient costs associated with external beam radiotherapy treatment for localized prostate cancer: the benefits of hypofractionated over conventionally fractionated radiotherapy.

Science.gov (United States)

Sethukavalan, Perakaa; Cheung, Patrick; Tang, Colin I; Quon, Harvey; Morton, Gerard; Nam, Robert; Loblaw, Andrew

2012-04-01

To estimate the out-of-pocket costs for patients undergoing external beam radiotherapy (EBRT) for prostate cancer and calculate the patient-related savings of being treated with a 5-fraction versus a standard 39-fraction approach. Seventy patients accrued to the pHART3 (n = 84) study were analyzed for out-of-pocket patient costs as a result of undergoing treatment. All costs are in Canadian dollars. Using the postal code of the patient's residence, the distance between the hospital and patient home was found using Google Maps. The Canada Revenue Agency automobile allowance rate was then applied to determine the cost per kilometer driven. The average cost of travel from the hospital and pHART3 patient's residence was $246 per person after five trips. In a standard fractionation regimen, pHART3 patients would have incurred an average cost of $1921 after 39 visits. The patients receiving hypofractionated radiotherapy would have paid an average of $38 in parking while those receiving conventional treatment would have paid $293. The difference in out-of-pocket costs for the patients receiving a standard versus hypofractionated treatment was $1930. Medium term prospective data shows that hypofractionated radiotherapy is an effective treatment method for localized prostate cancer. Compared to standard EBRT, hypofractionated radiotherapy requires significantly fewer visits. Due to the long distance patients may have to travel to the cancer center and the expense of parking, the short course treatment saves each patient an average of $1900. A randomized study of standard versus hypofractionated accelerated radiotherapy should be conducted to confirm a favorable efficacy and tolerability profile of the shorter fractionation scheme.

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

International Nuclear Information System (INIS)

Reinfuss, M.; Kowalska, T.; Glinski, C.

2000-01-01

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)

An original accelerated radiotherapy schedule in stage III to IV head and neck cancers. Results in a multicenter setting

International Nuclear Information System (INIS)

Allal, A.S.

2000-01-01

Background: Accelerated radiotherapy delivery has recently been shown to be effective in overcoming repopulation during fractionated radiotherapy. The therapeutic ratio may be particularly favorable for 5-week regimens. This study reports the feasibility and results of a particular accelerated schedule in Stage III to IV head and neck carcinomas used in a multicenter setting. Patients and Methods: Seventy-four patients with Stage III (26 patients) or IV (48 patients) head and neck carcinomas were treated with a 5-week accelerated schedule (69.9 to 69.8 Gy in 41 to 40 fractions over a period of 35 to 36 days). Treatment began with 20 Gy in 10 daily fractions to initial involved sites, followed by bi-fractionated radiotherapy (2x1.6 Gy to 1.66 Gy/day) to a larger head and neck volume. Thirty-six (49%) patients received induction chemotherapy (median 3 cycles, range 1 to 4 cycles). Results: Grade 3 or 4 (RTOG) confluent mucositis was observed in 57 patients (77%) and Grade 3 dysphagia in 33 patients (44%). Grade 3 or 4 (RTOG-EORTC) late complications were scored in 10.5% of cases. The 5-year actuarial locoregional control rate was 56% (95% CI: 42 to 71). The 5-year overall actuarial survival was 32% (95% CI: 18 to 46). Induction chemotherapy was not associated with a more favorable outcome. Conclusions: This study demonstrates the feasibility of this schedule in a multicenter setting. The oncologic results appear similar to those obtained by other accelerated regimens, while the rate of late complications seems acceptable. Five-week accelerated regimens warrant further evaluation, particularly in conjunction with concomitant chemotherapy, in the framework of prospective trials. (orig.) [de

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

International Nuclear Information System (INIS)

Goyal, Sharad; Daroui, Parima; Khan, Atif J; Kearney, Thomas; Kirstein, Laurie; Haffty, Bruce G

2013-01-01

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

Radiotherapy management of brain metastases using conventional linear accelerator.

Science.gov (United States)

Matzenauer, Marcel; Vrana, David; Vlachova, Zuzana; Cwiertka, Karel; Kalita, Ondrej; Melichar, Bohuslav

2016-09-01

As treatments for primary cancers continue to improve life expectancy, unfortunately, brain metastases also appear to be constantly increasing and life expectancy for patients with brain metastases is low. Longer survival and improved quality of life may be achieved using localised radiological and surgical approaches in addition to low dose corticosteroids. Stereotactic brain radiotherapy is one rapidly evolving localized radiation treatment. This article describes our experience with stereotactic radiotherapy using a linear accelerator. We reviewed patients treated with stereotactic radiotherapy, from the time of its introduction into daily practice in our Department of Oncology in 2014. We collected the data on patient treatment and predicted survival based on prognostic indices and actual patient outcome. A total of 10 patients were treated by stereotactic radiotherapy, in one case in combination with whole brain radiotherapy and hippocampal sparing. There was no significant treatment related toxicity during the treatment or follow-up and due to the small number of fractions, the overall tolerance of the treatment was excellent. The patient intrafractional movement in all cases was under 1 mm suggesting that 1 mm margin around the CTV to create the PTV is sufficient and also that patient immobilization using the thermoplastic mask compared with invasive techniques, is feasible. We also found that prognostic indices such as the Graded Prognostic Assessment provide accurate predictions of patient survival. Based on our current evidence, patients with brain metastases fit enough, should be considered for stereotactic radiotherapy treatment.

Estimating radiotherapy demands in South East Asia countries in 2025 and 2035 using evidence-based optimal radiotherapy fractions.

Science.gov (United States)

Yahya, Noorazrul; Roslan, Nurhaziqah

2018-01-08

As about 50% of cancer patients may require radiotherapy, the demand of radiotherapy as the main treatment to treat cancer is likely to rise due to rising cancer incidence. This study aims to quantify the radiotherapy demand in countries in Southeast Asia (SEA) in 2025 and 2035 using evidence-based optimal radiotherapy fractions. SEA country-specific cancer incidence by tumor site for 2015, 2025 and 2035 was extracted from the GLOBOCAN database. We utilized the optimal radiotherapy utilization rate model by Wong et al. (2016) to calculate the optimal number of fractions for all tumor sites in each SEA country. The available machines (LINAC & Co-60) were extracted from the IAEA's Directory of Radiotherapy Centres (DIRAC) from which the number of available fractions was calculated. The incidence of cancers in SEA countries are expected to be 1.1 mil cases (2025) and 1.4 mil (2035) compared to 0.9 mil (2015). The number of radiotherapy fractions needed in 2025 and 2035 are 11.1 and 14.1 mil, respectively, compared to 7.6 mil in 2015. In 2015, the radiotherapy fulfillment rate (RFR; required fractions/available fractions) varied between countries with Brunei, Singapore and Malaysia are highest (RFR > 1.0 - available fractions > required fractions), whereas Cambodia, Indonesia, Laos, Myanmar, Philippines, Timor-Leste and Vietnam have RFR fractions, estimation for number of machines required can be obtained which will guide acquisition of machines in SEA countries. RFR is low with access varied based on the economic status. © 2018 John Wiley & Sons Australia, Ltd.

Tissue kinetics in mouse tongue mucosa during daily fractionated radiotherapy

International Nuclear Information System (INIS)

Doerr, W.; Emmendoerfer, H.; Weber-Frisch, M.

1996-01-01

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)

Accelerated Intensity-Modulated Radiotherapy to Breast in Prone Position: Dosimetric Results

International Nuclear Information System (INIS)

De Wyngaert, J. Keith; Jozsef, Gabor; Mitchell, James; Rosenstein, Barry; Formenti, Silvia C.

2007-01-01

Purpose: To report the physics and dosimetry results of a trial of accelerated intensity-modulated radiotherapy to the whole breast with a concomitant boost to the tumor bed in patients treated in the prone position. Methods and Materials: Patients underwent computed tomography planning and treatment in the prone position on a dedicated treatment platform. The platform has an open aperture on the side to allow for the index breast to fall away from the chest wall. Noncontrast computed tomography images were acquired at 2.5- or 3.75-mm-thick intervals, from the level of the mandible to below the diaphragm. A dose of 40.5 Gy was delivered to the entire breast at 2.7-Gy fractions in 15 fractions. An additional dose of 0.5 Gy was delivered as a concomitant boost to the lumpectomy site, with a 1-cm margin, using inverse planning, for a total dose of 48 Gy in 15 fractions. No more than 10% of the heart and lung volume was allowed to receive >18 and >20 Gy, respectively. Results: Between September 2003 and August 2005, 91 patients were enrolled in the study. The median volume of heart that received ≥18 Gy was 0.5%, with a maximal value of 4.7%. The median volume of ipsilateral lung that received ≥20 Gy was 0.8%, with a maximum of 7.2%. Conclusion: This technique for whole breast radiotherapy is feasible and enables an accelerated regimen in the prone position while sparing the lung and heart

Monte Carlo based simulation of LIAC intraoperative radiotherapy accelerator along with beam shaper applicator

Directory of Open Access Journals (Sweden)

N Heidarloo

2017-08-01

Full Text Available Intraoperative electron radiotherapy is one of the radiotherapy methods that delivers a high single fraction of radiation dose to the patient in one session during the surgery. Beam shaper applicator is one of the applicators that is recently employed with this radiotherapy method. This applicator has a considerable application in treatment of large tumors. In this study, the dosimetric characteristics of the electron beam produced by LIAC intraoperative radiotherapy accelerator in conjunction with this applicator have been evaluated through Monte Carlo simulation by MCNP code. The results showed that the electron beam produced by the beam shaper applicator would have the desirable dosimetric characteristics, so that the mentioned applicator can be considered for clinical purposes. Furthermore, the good agreement between the results of simulation and practical dosimetry, confirms the applicability of Monte Carlo method in determining the dosimetric parameters of electron beam  intraoperative radiotherapy

Accelerated Hyperfractionated Radiotherapy for Locally Advanced Uterine Cervix Cancers

International Nuclear Information System (INIS)

Seo, Young Seok; Cho, Chul Koo; Yoo, Seong Yul

2008-01-01

To assess the efficacy of the use of accelerated hyperfractionated radiotherapy (AHRT) for locally advanced uterine cervix cancers. Between May 2000 and September 2002, 179 patients were identified with FIGO stage IIB, IIIB, and IVA cancers. Of the 179 patients, 45 patients were treated with AHRT (AHRT group) and 134 patients were treated with conventional radiotherapy (CRT group), respectively. Patients undergoing the AHRT regimen received a dose of 30 Gy in 20 fractions (1.5 Gyx2 fractions/day) to the whole pelvis. Subsequently, with a midline block, we administered a parametrial boost with a dose of 20 Gy using 2 Gy fractions. Patients also received two courses of low-dose-rate brachytherapy, up to a total dose of 85∼90 Gy to point A. In the CRT group of patients, the total dose to point A was 85∼90 Gy. The overall treatment duration was a median of 37 and 66 days for patients that received AHRT and CRT, respectively. Statistical analysis was calculated by use of the Kaplan-Meier method, the log-rank test, and Chi-squared test. For patients that received cisplatin-based concurrent chemotherapy and radiotherapy, the local control rate at 5 years was 100% and 79.2% for the AHRT and CRT group of patients, respectively (p=0.028). The 5-year survival rate for patients with a stage IIB bulky tumor was 82.6% and 62.1% for the AHRT group and CRT group, respectively (p=0.040). There was no statistically significant difference for severe late toxicity between the two groups (p=0.561). In this study, we observed that treatment with AHRT with concurrent chemotherapy allows a significant advantage of local control and survival for locally advanced uterine cervix cancers

Intra-fraction motion of larynx radiotherapy

Science.gov (United States)

Durmus, Ismail Faruk; Tas, Bora

2018-02-01

In early stage laryngeal radiotherapy, movement is an important factor. Thyroid cartilage can move from swallowing, breathing, sound and reflexes. The effects of this motion on the target volume (PTV) during treatment were examined. In our study, the target volume movement during the treatment for this purpose was examined. Thus, setup margins are re-evaluated and patient-based PTV margins are determined. Intrafraction CBCT was scanned in 246 fractions for 14 patients. During the treatment, the amount of deviation which could be lateral, vertical and longitudinal axis was determined. ≤ ± 0.1cm deviation; 237 fractions in the lateral direction, 202 fractions in the longitudinal direction, 185 fractions in the vertical direction. The maximum deviation values were found in the longitudinal direction. Intrafraction guide in laryngeal radiotherapy; we are sure of the correctness of the treatment, the target volume is to adjust the margin and dose more precisely, we control the maximum deviation of the target volume for each fraction. Although the image quality of intrafraction-CBCT scans was lower than the image quality of planning CT, they showed sufficient contrast for this work.

Reirradiation of brain and skull base tumors with fractionated stereotactic radiotherapy

International Nuclear Information System (INIS)

Tokuuye, Koichi; Akine, Yasuyuki; Sumi, Minako; Kagami, Yoshikazu; Ikeda, Hiroshi; Oyama, Hiroshi; Inou, Yasushi; Shibui, Soichiro; Nomura, Kazuhiro

1998-01-01

Purpose: We evaluated the feasibility of fractionated stereotactic radiotherapy for small intracranial recurrences after conventional radiotherapy. Methods and Materials: Nineteen patients who had initially undergone conventional radiotherapy to intracranial lesions, receiving a median total dose of 50 Gy in 5 weeks, were retreated with stereotactic radiotherapy for their recurrences and received a median total dose of 42 Gy in seven fractions over 2.3 weeks. Results: Of the 19 patients, 15 achieved local control 3-51 months after reirradiation. No patient suffered from acute reaction, but one patient with a history of extensive radiotherapy developed progressive radionecrosis 9 months after reirradiation. Conclusions: Fractionated stereotactic radiotherapy of intracranial recurrences appears to be effective in achieving in local control with negligible morbidity. We believe it merits further investigation in a prospective study

Evidence-based optimal number of radiotherapy fractions for cancer: A useful tool to estimate radiotherapy demand.

Science.gov (United States)

Wong, Karen; Delaney, Geoff P; Barton, Michael B

2016-04-01

The recently updated optimal radiotherapy utilisation model estimated that 48.3% of all cancer patients should receive external beam radiotherapy at least once during their disease course. Adapting this model, we constructed an evidence-based model to estimate the optimal number of fractions for notifiable cancers in Australia to determine equipment and workload implications. The optimal number of fractions was calculated based on the frequency of specific clinical conditions where radiotherapy is indicated and the evidence-based recommended number of fractions for each condition. Sensitivity analysis was performed to assess the impact of variables on the model. Of the 27 cancer sites, the optimal number of fractions for the first course of radiotherapy ranged from 0 to 23.3 per cancer patient, and 1.5 to 29.1 per treatment course. Brain, prostate and head and neck cancers had the highest average number of fractions per course. Overall, the optimal number of fractions was 9.4 per cancer patient (range 8.7-10.0) and 19.4 per course (range 18.0-20.7). These results provide valuable data for radiotherapy services planning and comparison with actual practice. The model can be easily adapted by inserting population-specific epidemiological data thus making it applicable to other jurisdictions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Accelerated Fractionation In The Treatment of Brain Metastasis From Non-Small Cell Carcinoma of The Lung

International Nuclear Information System (INIS)

Hong, Seong Eon

1994-01-01

Purpose: Metastatic cancer to the brain is a major problem for the patients with bronchogenic carcinoma, and most of these patients have a limited survival expectancy. To increase tumor control and/or to decrease late morbidity with possible shortening in over-all treatment period, multiple daily fraction technique for brain metastasis was performed. The author represented the results of accelerated fractionation radiotherapy in patients with brain metastases from non-small cell lung cancer. Materials and Methods: Twenty-six patients with brain metastases from non-small cell lung cancer between 1991 and 1993 received brain radiotherapy with a total dose of 48 Gy, at 2 Gy per fraction, twice a day with a interfractional period of 6 hours, and delivered 5 days a week. The whole brain was treated to 40 Gy and boost dose escalated to 8 Gy for single metastatic lesion by reduced field. Twenty-four of the 26 patients completed the radiotherapy. Radiotherapy was interrupted in two patients suggesting progressive intracerebral disease. Results: This radiotherapy regimen appears to be comparable to the conventional schema in relief from symptoms. Three of the 24 patients experienced nausea and or vomiting during the course of treatment because of acute irradiation toxicity. The author observed no excessive toxicity with escalating dose of irradiation. An increment in median survival, although not statistically significant (p>0.05), was noted with escalating doses(48 Gy) of accelerated fractionation (7 months) compared to conventional treatment(4.5 months). Median survival also increased in patients with brain solitary metastasis(9 months) compared to multiple extrathoracic sites(4 months), and in patients with good performance status(9 months versus 3.5 months), they were statistically significant(p<0.01). Conclusion: The increment in survival in patients with good prognostic factors such as controlled primary lesion, metastasis in brain only, and good performance status

Proliferation studies for different radiotherapy fractionation regimes

International Nuclear Information System (INIS)

Jones, L.

1996-01-01

Full text: This study was undertaken to investigate extended treatment schedules and compare the differences between schedules for highly proliferative tumours. Treatment schedules can be extended for various reasons e.g. public holidays, early side effects. For highly proliferative tumours this can dramatically reduce the effective dose delivered to the tumour. To deduce the most effective schedule fractionation regimes are compared to a common schedule so that the effects can be understood. Thus an equation to allow this to be done for the proliferative case has been derived. (i) The linear quadratic model with proliferation has been used to investigate the effect on biological effective dose (BED) when treatment schedules are extended. (ii) An equation was derived for comparison with a standard effective dose (SED) of 2Gy/fraction given daily 5 days per week, this is a common schedule in most radiotherapy centres. The SED equation derived for the proliferative case is where n 1 and n 2 are the number of fractions for the initial and equivalent schedules respectively, d 1 is the dose delivered per fraction for the initial schedules. T 1 is the time taken for the initial schedule (in days) and T p is the proliferation half life for the tumour involved. SEDs were calculated for the CHART regime of 36 fractions at 1.5 Gy in 12 days (Saunders et al. 1988, cited in Fowler J F, Brit. J. Radiol. 62: 679-694, 1989) and various other schedules. Late effects of these schedules and their standard equivalents were compared. The dose required to achieve the same BED when a treatment schedule is extended has been found to be quite large in some circumstances. For breast tumours a loss of 2Gy 10 BED to tumour occurs after ten days extension of treatment time (T p =12 days,T k =12 days). For head and neck tumours a loss of 2Gy 10 BED occurs after only three and a half days (T p =3 days). From these results it seems that an accelerated fractionation schedule would be advantageous

Twice-a-day fractionated radiotherapy for head and neck cancer

Energy Technology Data Exchange (ETDEWEB)

Kita, Midori [Tokyo Metropolitan Hospital of Fuchu (Japan)

1996-12-01

To improve the local control rate in radiotherapy for hand and neck cancer, several prospected twice-a-day fractionated radiotherapy (TDRF) were conducted in Tokyo Women`s Medical College. T2 glottic cancer was irradiated with 1.5 Gy/fraction, 2 fraction/day to a total dose of 72 Gy. Five cumulative local control rate was 88.2%. Locally advanced head and neck cancer was treated with TDFR and systemic chemotherapy. Response rate was 100%. Palliative radiotherapy with TDFR was done to relive from the pain and other symptoms for advanced and recurrent cases. Nine cases of 11 were relieved from the symptoms. These results was suggested the TDFR was useful to improve the local control rate. (author)

Twice-a-day fractionated radiotherapy for head and neck cancer

International Nuclear Information System (INIS)

Kita, Midori

1996-01-01

To improve the local control rate in radiotherapy for hand and neck cancer, several prospected twice-a-day fractionated radiotherapy (TDRF) were conducted in Tokyo Women's Medical College. T2 glottic cancer was irradiated with 1.5 Gy/fraction, 2 fraction/day to a total dose of 72 Gy. Five cumulative local control rate was 88.2%. Locally advanced head and neck cancer was treated with TDFR and systemic chemotherapy. Response rate was 100%. Palliative radiotherapy with TDFR was done to relive from the pain and other symptoms for advanced and recurrent cases. Nine cases of 11 were relieved from the symptoms. These results was suggested the TDFR was useful to improve the local control rate. (author)

Hippocampal-Sparing Whole-Brain Radiotherapy: A 'How-To' Technique Using Helical Tomotherapy and Linear Accelerator-Based Intensity-Modulated Radiotherapy

International Nuclear Information System (INIS)

Gondi, Vinai; Tolakanahalli, Ranjini; Mehta, Minesh P.; Tewatia, Dinesh; Rowley, Howard; Kuo, John S.; Khuntia, Deepak; Tome, Wolfgang A.

2010-01-01

Purpose: Sparing the hippocampus during cranial irradiation poses important technical challenges with respect to contouring and treatment planning. Herein we report our preliminary experience with whole-brain radiotherapy using hippocampal sparing for patients with brain metastases. Methods and Materials: Five anonymous patients previously treated with whole-brain radiotherapy with hippocampal sparing were reviewed. The hippocampus was contoured, and hippocampal avoidance regions were created using a 5-mm volumetric expansion around the hippocampus. Helical tomotherapy and linear accelerator (LINAC)-based intensity-modulated radiotherapy (IMRT) treatment plans were generated for a prescription dose of 30 Gy in 10 fractions. Results: On average, the hippocampal avoidance volume was 3.3 cm 3 , occupying 2.1% of the whole-brain planned target volume. Helical tomotherapy spared the hippocampus, with a median dose of 5.5 Gy and maximum dose of 12.8 Gy. LINAC-based IMRT spared the hippocampus, with a median dose of 7.8 Gy and maximum dose of 15.3 Gy. On a per-fraction basis, mean dose to the hippocampus (normalized to 2-Gy fractions) was reduced by 87% to 0.49 Gy 2 using helical tomotherapy and by 81% to 0.73 Gy 2 using LINAC-based IMRT. Target coverage and homogeneity was acceptable with both IMRT modalities, with differences largely attributed to more rapid dose fall-off with helical tomotherapy. Conclusion: Modern IMRT techniques allow for sparing of the hippocampus with acceptable target coverage and homogeneity. Based on compelling preclinical evidence, a Phase II cooperative group trial has been developed to test the postulated neurocognitive benefit.

Fractionated stereotactic radiotherapy in patients with acromegaly: an interim single-centre audit

DEFF Research Database (Denmark)

Roug, Anne Stidsholt; Rasmussen, Åse Krogh; Juhler, M

2010-01-01

To evaluate the effect of fractionated stereotactic radiotherapy (FSRT) in acromegaly in a retrospective analysis.......To evaluate the effect of fractionated stereotactic radiotherapy (FSRT) in acromegaly in a retrospective analysis....

Evaluation of inter-fraction error during prostate radiotherapy

International Nuclear Information System (INIS)

Komiyama, Takafumi; Nakamura, Koji; Motoyama, Tsuyoshi; Onishi, Hiroshi; Sano, Naoki

2008-01-01

The purpose of this study was to evaluate inter-fraction error (inter-fraction set-up error+inter-fraction internal organ motion) between treatment planning and delivery during radiotherapy for localized prostate cancer. Twenty three prostate cancer patients underwent image-guided radical irradiation with the CT-linac system. All patients were treated in the supine position. After set-up with external skin markers, using CT-linac system, pretherapy CT images were obtained and isocenter displacement was measured. The mean displacement of the isocenter was 1.8 mm, 3.3 mm, and 1.7 mm in the left-right, ventral-dorsal, and cranial-caudal directions, respectively. The maximum displacement of the isocenter was 7 mm, 12 mm, and 9 mm in the left-right, ventral-dorsal, and cranial-caudal directions, respectively. The mean interquartile range of displacement of the isocenter was 1.8 mm, 3.7 mm, and 2.0 mm in the left-right, ventral-dorsal, and cranial-caudal directions, respectively. In radiotherapy for localized prostate cancer, inter-fraction error was largest in the ventral-dorsal directions. Errors in the ventral-dorsal directions influence both local control and late adverse effects. Our study suggested the set-up with external skin markers was not enough for radical radiotherapy for localized prostate cancer, thereby those such as a CT-linac system for correction of inter-fraction error being required. (author)

Endocrine and visual function after fractionated stereotactic radiotherapy of perioptic tumors

Energy Technology Data Exchange (ETDEWEB)

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.)

Endocrine and visual function after fractionated stereotactic radiotherapy of perioptic tumors

International Nuclear Information System (INIS)

Kocher, M.; Semrau, R.; Mueller, R.P.; Treuer, H.; Hoevels, M.; Sturm, V.

2013-01-01

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.)

Variations in tumour oxygen tension (pO2) during accelerated radiotherapy of head and neck carcinoma

International Nuclear Information System (INIS)

Guichard, M.; Eschwege, F.; Luboinski, B.; Wibault, P.; Weeger, P.; Lusinchi, A.; Lartigau, E.

1998-01-01

The study was performed to assess the effect of accelerated radiotherapy on oxygenation of primary tumours and metastatic nodes in patients with advanced head and neck tumours. In 14 patients with head and neck tumour, oxygen tension (pO 2 ) was evaluated in normal tissues and tumours (primary tumour or metastatic neck node) before (0 Gy) and after 2 weeks (32 Gy) of accelerated radiotherapy (70 Gy in 3.5 weeks, with three daily fractions). Radiotherapy was combined with carbogen breathing in 5 patients. pO 2 was measured using a polarographic technique. For pooled normal tissues, median pO 2 was 38 mmHg before treatment and 46 mmHg after 2 weeks. For tumours, very low values ( 2 12 mmHg before treatment versus 26 mmHg after 2 weeks, P 2 was 44 mmHg at 2 weeks, compared with 13.5 mmHg before treatment (P=0.05). Very low pO 2 values, corresponding to tumour hypoxia, were found in the tumours (primary and metastatic neck nodes) prior to accelerated treatment. During the first 2 weeks of accelerated treatment, an increase in median pO 2 was found in nine of the 14 tumours, together with a decrease in the frequency of very low values. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Hypofractionated Accelerated Radiotherapy Using Concomitant Intensity-Modulated Radiotherapy Boost Technique for Localized High-Risk Prostate Cancer: Acute Toxicity Results

International Nuclear Information System (INIS)

Lim, Tee S.; Cheung, Patrick; Loblaw, D. Andrew; Morton, Gerard; Sixel, Katharina E.; Pang, Geordi; Basran, Parminder; Zhang Liying; Tirona, Romeo; Szumacher, Ewa; Danjoux, Cyril; Choo, Richard; Thomas, Gillian

2008-01-01

Purpose: To evaluate the acute toxicities of hypofractionated accelerated radiotherapy (RT) using a concomitant intensity-modulated RT boost in conjunction with elective pelvic nodal irradiation for high-risk prostate cancer. Methods and Materials: This report focused on 66 patients entered into this prospective Phase I study. The eligible patients had clinically localized prostate cancer with at least one of the following high-risk features (Stage T3, Gleason score ≥8, or prostate-specific antigen level >20 ng/mL). Patients were treated with 45 Gy in 25 fractions to the pelvic lymph nodes using a conventional four-field technique. A concomitant intensity-modulated radiotherapy boost of 22.5 Gy in 25 fractions was delivered to the prostate. Thus, the prostate received 67.5 Gy in 25 fractions within 5 weeks. Next, the patients underwent 3 years of adjuvant androgen ablative therapy. Acute toxicities were assessed using the Common Terminology Criteria for Adverse Events, version 3.0, weekly during treatment and at 3 months after RT. Results: The median patient age was 71 years. The median pretreatment prostate-specific antigen level and Gleason score was 18.7 ng/L and 8, respectively. Grade 1-2 genitourinary and gastrointestinal toxicities were common during RT but most had settled at 3 months after treatment. Only 5 patients had acute Grade 3 genitourinary toxicity, in the form of urinary incontinence (n = 1), urinary frequency/urgency (n = 3), and urinary retention (n = 1). None of the patients developed Grade 3 or greater gastrointestinal or Grade 4 or greater genitourinary toxicity. Conclusion: The results of the present study have indicated that hypofractionated accelerated RT with a concomitant intensity-modulated RT boost and pelvic nodal irradiation is feasible with acceptable acute toxicity

Palliative radiotherapy for painful bone metastases, single versus multiple fraction treatment: a literature review

International Nuclear Information System (INIS)

McKee, L.

2005-01-01

Palliative radiotherapy provides pain relief for patients with painful bone metastases. The practice among radiation oncologists as to whether a large single fraction is most effective, or whether multiple smaller fractions are preferable in providing the quickest, most durable pain relief is inconsistent. A literature review was completed to see if there is consensus about whether there is better pain response and control following single versus multiple fraction radiotherapy. The Pub Med search engine was used to find all reported studies comparing single and multiple fraction radiotherapy for painful bone metastases. Each article was reviewed according to specific criteria. A generalized conclusion was ascertained from each study and then compared. Among the studies reviewed, the consensus concluded that single fraction radiotherapy was the better choice for palliation of painful bone metastases. According to the literature reviewed, single fraction radiotherapy provides adequate pain relief with reasonable duration of pain response. (author)

Radiobiologically based assessments of the net costs of fractionated radiotherapy

International Nuclear Information System (INIS)

Dale, Roger G.; Jones, Bleddyn

1996-01-01

Purpose: To examine how the long-term costs of radiation therapy may be influenced by modifications to fractionation schemes, and how any improvements in tumor control might, in principle, be translated into a potential cost saving for the responsible healthcare organization. Methods and Materials: Standard radiobiological modeling based on the linear-quadratic (LQ) model is combined with financial parameters relating to the estimated costs of different aspects of radiotherapy treatment delivery. The cost model includes provision for the long-term costs of treatment failure and enables the extra costs of near optimal radiotherapy to be balanced against suboptimal alternatives, which are more likely to be associated with further radiotherapy, salvage surgery, and continuing care. Results: A number of caveats are essential in presenting a model such as this for the first time, and these are clearly stated. However, a recurring observation is that, in terms of the whole cost of supporting a patient from first radiotherapy treatment onwards, high quality radiotherapy (i.e., based on individual patterns of fractionation that are near optimal for particular subpopulations of tumor) will frequently be associated with the lowest global cost. Conclusions: This work adds weight to the case for identifying fast and accurate predictive assay techniques, and supports the argument that suboptimal radiotherapy is usually more costly in the long term. Although the article looks only at the cost-benefit consequences of altered patterns of fractionation, the method will, in principle, have application to other changes in the way radiotherapy can be performed, e.g., to examining the cost-benefit aspects of tumor dose escalation as a consequence of using advanced conformal treatment planning

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

Directory of Open Access Journals (Sweden)

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.

The selection of patients for accelerated radiotherapy on the basis of tumor growth kinetics and intrinsic radiosensitivity

International Nuclear Information System (INIS)

Tucker, S.L.; Kang-Sow Chan

1990-01-01

Mathematical modelling was used to reach qualitative conclusions concerning the relative rate of local tumor control that might be achieved by using accelerated fractionation to treat only the patients with the most rapidly growing rumors, compared with the control rated that could be expected from either conventional or accelerated radiotherapy alone. The results suggest that concomitant boost therapy is equally or more effective than conventional dose fractionation for all tumors, regardless of their growth kinetics. For tumors with very short clonogen doubling times, CHART (continuous hyperfractionated accelerated radiotherapy) may be even more effective than concomitant boost treatment, but CHART is less effective than conventional or concomitant boost therapy for tumors with longer clonogen doubling times. Thus, there is a rationale for using a predictive assay of tumor clonogen doubling times to identify the patients who should be treated with CHART. However, improvements in local tumor control resulting from concomitant boost treatment or the selective use of CHART are not likely to be apparent in the population as a whole, because the overall control rated are largely determined by refractory tumors having little chance of control with any of the treatments and by higher responsive tumors that are likely to be controlled regardless of the treatment choice. Differences in control rated with different treatment strategies are most apparent in the stochastic fraction of the population, which excludes those patients for whom there is either very little change (e.g. 99%) of achieving local control with both treatments. The stochastic fraction can be approximated by excluding those patients with the most radioresistant and the most radiosensitive tumors, since intrinsic tumor radiosensitivity appears to be the single most important factor determining treatment outcome. (author). 32 refs.; 4 figs.; 5 tabs

Fractionated stereotactic radiotherapy for craniopharyngiomas

International Nuclear Information System (INIS)

Schulz-Ertner, Daniela; Frank, Claudia; Herfarth, Klaus K.; Rhein, Bernhard; Wannenmacher, Michael; Debus, Juergen

2002-01-01

Purpose: To investigate outcome and toxicity after fractionated stereotactic radiation therapy (FSRT) in patients with craniopharyngiomas. Methods and Materials: Twenty-six patients with craniopharyngiomas were treated with FSRT between May 1989 and February 2001. Median age was 33.5 years (range: 5-57 years). Nine patients received FSRT after surgery as primary treatment, and 17 patients were irradiated for recurrent tumor or progressive growth after initial surgery. Median target dose was 52.2 Gy (range: 50.0-57.6 Gy) with conventional fractionation. Follow-up included MRI and neurologic, ophthalmologic, and endocrinologic examinations. Results: The median follow-up was 43 months (range: 7-143 months). The actuarial local control rate and actuarial overall survival rates were 100% and 100%, respectively, at 5 years and 100% and 83%, respectively, at 10 years. Four patients showed complete response, 14 patients showed partial response, and 8 patients remained stable. In 5 patients, vision improved after radiation therapy. Acute toxicity was mild. One patient required cyst drainage 3 months after radiotherapy. Late toxicity after radiotherapy included impairment of hormone function in 3 out of 18 patients at risk. We did not observe any vision impairment, radionecrosis, or secondary malignancies. Conclusions: FSRT is effective and safe in the treatment of cystic craniopharyngiomas. Toxicity is extremely low using this conformal technique

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

International Nuclear Information System (INIS)

Song, Changhoon; Wu, Honggyun; Chang, Hak; Kim, Il Han; Ha, Sung W.

2014-01-01

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)

Safety and adverse events of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) for rectal cancer

International Nuclear Information System (INIS)

Doi, Hiroshi; Kamikonya, Norihiko; Hirota, Shozo; Beppu, Naohito; Yanagi, Hidenori

2014-01-01

We presented good tolerability and short-term outcomes of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART; 25 Gy in 10 fractions for 5 days) combined with chemotherapy in a total of 73 patients with lower rectal cancer. Age, gender, tumor differentiation, and the type of surgery seemed to have no apparent effects on toxicity of SC-HART. SC-HART appeared to have a good feasibility for use in further clinical trials. (author)

Continuous hyperfractionated accelerated radiotherapy (chart) in localized cancer of the esophagus

International Nuclear Information System (INIS)

Powell, Melanie E.B.; Hoskin, Peter J.; Saunders, Michele I.; Foy, Christopher J.W.; Dische, Stanley

1997-01-01

Purpose: To assess the efficacy and toxicity of continuous hyperfractionated accelerated radiotherapy (CHART) in locoregional control compared with a historical group of patients treated with conventionally fractionated radical radiotherapy. Methods and Materials: Between 1985 and 1994, 54 patients with localized esophageal cancer were treated with CHART. Twenty-eight patients received CHART alone (54 Gy in 36 fractions over 12 consecutive days) and 15 were given intravenous mitomycin C and cisplatin on days 10 and 13, respectively. Eleven patients received 40.5 Gy in 27 fractions over 9 days, followed by a single high-dose-rate intraluminal brachytherapy insertion of 15 Gy at 1 cm. Results: Acute toxicity was well tolerated and dysphagia was improved in 35 patients (65%), with 28 (52%) eating a normal diet by week 12. This compares with an improvement in dysphagia score in 72% of the conventionally treated group. The median duration of relief of dysphagia was 7.8 months (range 0-41.4) in the CHART group compared with 5.5 months (range 0-48) in the controls. Strictures developed in 29 patients (61%) and 18 were confirmed on biopsy to be due to recurrent disease. Median survival was 12 months (range 0.5-112) in the CHART group and 15 months (range 3.6-56) in the control patients. Conclusion: CHART is well tolerated and achieves a high rate of local control. Palliation in the short overall treatment time of esophageal cancer is an advantage in these patients whose median survival is only 12 months

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

DEFF Research Database (Denmark)

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

2015-01-01

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...

Accelerated hypofractionated radiotherapy as adjuvant regimen after conserving surgery for early breast cancer: interim report of toxicity after a minimum follow up of 3 years

Science.gov (United States)

2010-01-01

Background Accelerated hypofractionation is an attractive approach for adjuvant whole breast radiotherapy. In this study we evaluated the adverse effects at least 3 years post an accelerated hypofractionated whole breast radiotherapy schedule. Methods From October 2004 to March 2006, 39 consecutive patients aged over 18 years with pTis, pT1-2, pN0-1 breast adenocarcinoma who underwent conservative surgery were treated with an adjuvant accelerated hypofractionated radiotherapy schedule consisting of 34 Gy in 10 daily fractions over 2 weeks to the whole breast, followed after 1 week by an electron boost dose of 8 Gy in a single fraction to the tumour bed. Skin and lung radiation toxicity was evaluated daily during therapy, once a week for one month after radiotherapy completion, every 3 months for the first year and from then on every six months. In particular lung toxicity was investigated in terms of CT density evaluation, pulmonary functional tests, and clinical and radiological scoring. Paired t-test, Chi-square test and non-parametric Wilcoxon test were performed. Results After a median follow-up of 43 months (range 36-52 months), all the patients are alive and disease-free. None of the patients showed any clinical signs of lung toxicity, no CT-lung toxicity was denoted by radiologist on CT lung images acquired about 1 year post-radiotherapy, no variation of pulmonary density evaluated in terms of normalised Hounsfield numbers was evident. Barely palpable increased density of the treated breast was noted in 9 out of 39 patients (in 2 patients this toxicity was limited to the boost area) and teleangectasia (radiotherapy schedule investigated in this study (i.e 34 Gy in 3.4 Gy/fr plus boost dose of 8 Gy in single fraction) is a feasible and safe treatment and does not lead to adjunctive acute and late toxicities. A longer follow up is necessary to confirm these favourable results. PMID:20100335

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

International Nuclear Information System (INIS)

Leonard, Charles E.; Tallhamer, Michael M.S.; Johnson, Tim; Hunter, Kari C.M.D.; Howell, Kathryn; Kercher, Jane; Widener, Jodi; Kaske, Terese; Paul, Devchand; Sedlacek, Scot; Carter, Dennis L.

2010-01-01

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.

The first clinical implementation of real-time image-guided adaptive radiotherapy using a standard linear accelerator.

Science.gov (United States)

Keall, Paul J; Nguyen, Doan Trang; O'Brien, Ricky; Caillet, Vincent; Hewson, Emily; Poulsen, Per Rugaard; Bromley, Regina; Bell, Linda; Eade, Thomas; Kneebone, Andrew; Martin, Jarad; Booth, Jeremy T

2018-04-01

Until now, real-time image guided adaptive radiation therapy (IGART) has been the domain of dedicated cancer radiotherapy systems. The purpose of this study was to clinically implement and investigate real-time IGART using a standard linear accelerator. We developed and implemented two real-time technologies for standard linear accelerators: (1) Kilovoltage Intrafraction Monitoring (KIM) that finds the target and (2) multileaf collimator (MLC) tracking that aligns the radiation beam to the target. Eight prostate SABR patients were treated with this real-time IGART technology. The feasibility, geometric accuracy and the dosimetric fidelity were measured. Thirty-nine out of forty fractions with real-time IGART were successful (95% confidence interval 87-100%). The geometric accuracy of the KIM system was -0.1 ± 0.4, 0.2 ± 0.2 and -0.1 ± 0.6 mm in the LR, SI and AP directions, respectively. The dose reconstruction showed that real-time IGART more closely reproduced the planned dose than that without IGART. For the largest motion fraction, with real-time IGART 100% of the CTV received the prescribed dose; without real-time IGART only 95% of the CTV would have received the prescribed dose. The clinical implementation of real-time image-guided adaptive radiotherapy on a standard linear accelerator using KIM and MLC tracking is feasible. This achievement paves the way for real-time IGART to be a mainstream treatment option. Copyright © 2018 Elsevier B.V. All rights reserved.

Hyperfractionated Accelerated Radiotherapy (HART) for Anaplastic Thyroid Carcinoma: Toxicity and Survival Analysis

Energy Technology Data Exchange (ETDEWEB)

Dandekar, Prasad [Head and Neck/Thyroid Unit, Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Harmer, Clive; Barbachano, Yolanda [Department of Clinical Research and Development, Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Rhys-Evans, Peter; Harrington, Kevin; Nutting, Christopher [Head and Neck-Thyroid Unit, Royal Marsden NHS Foundation Trust, Chelsea, London (United Kingdom); Newbold, Kate [Head and Neck/Thyroid Unit, Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Consultant Clinical Oncologist, Royal Marsden NHS Foundation Trust, Chelsea, London (United Kingdom)

2009-06-01

Purpose: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive cancers, and the current protocol of hyperfractionated accelerated radiotherapy was initiated to improve survival while limiting toxicities. Methods and Materials: All patients with ATC from 1991 to 2002 were accrued and received megavoltage radiotherapy from the mastoid processes to the carina up to 60 Gy in twice-daily fractions of 1.8 and 2 Gy, 6 hours apart. Results: Thirty-one patients were accrued with a median age of 69 years, and 55% were women. Debulking was performed in 26%, and total thyroidectomy, in 6%, whereas 68% received radical radiotherapy alone. Local control data were available for 27 patients: 22% had a complete response, 26% had a partial response, 15% showed progressive disease, and 37% showed static disease. Median overall survival for all 31 patients was 70 days (95% confidence interval, 40-99). There was no significant difference in median survival between patients younger (70 days) and older than 70 years (42 days), between men (70 days) and women (49days), and between patients receiving postoperative radiotherapy (77 days) and radical radiotherapy alone (35 days). Grade III or higher skin erythema was seen in 56% patients; desquamation in 21%; dysphagia in 74%; and esophagitis in 79%. Conclusion: The current protocol failed to offer a significant survival benefit, was associated with severe toxicities, and thus was discontinued. There is a suggestion that younger patients with operable disease have longer survival, but this would require a larger study to confirm it.

Accelerated Deformable Registration of Repetitive MRI during Radiotherapy in Cervical Cancer

DEFF Research Database (Denmark)

Noe, Karsten Østergaard; Tanderup, Kari; Kiritsis, Christian

2006-01-01

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.    ...

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Guckenberger, Matthias; Mayer, Mario; Sweeney, Reinhart A.; Flentje, Michael [University Hospital Wuerzburg (Germany). Dept. of Radiation Oncology; Buttmann, Mathias [University Hospital Wuerzburg (Germany). Dept. of Neurology; Vince, Giles H. [University Hospital Wuerzburg (Germany). Dept. of Neurosurgery

2011-09-15

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.)

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

International Nuclear Information System (INIS)

Guckenberger, Matthias; Mayer, Mario; Sweeney, Reinhart A.; Flentje, Michael; Buttmann, Mathias; Vince, Giles H.

2011-01-01

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.)

Estimation of the optimal number of radiotherapy fractions for breast cancer: A review of the evidence.

Science.gov (United States)

Wong, Karen; Delaney, Geoff P; Barton, Michael B

2015-08-01

There is variation in radiotherapy fractionation practice, however, there is no evidence-based benchmark for appropriate activity. An evidence-based model was constructed to estimate the optimal number of fractions for the first course of radiotherapy for breast cancer to aid in services planning and performance benchmarking. The published breast cancer radiotherapy utilisation model was adapted. Evidence-based number of fractions was added to each radiotherapy indication. The overall optimal number of fractions was calculated based on the frequency of specific clinical conditions where radiotherapy is indicated and the recommended number of fractions for each condition. Sensitivity analysis was performed to assess the impact of uncertainties on the model. For the entire Australian breast cancer patient population, the estimated optimal number of fractions per patient was 16.8, 14.6, 13.7 and 0.8 for ductal carcinoma in situ, early, advanced and metastatic breast cancer respectively. Overall, the optimal number of fractions per patient was 14.4 (range 14.4-18.7). These results allow comparison with actual practices, and workload prediction to aid in services planning. The model can be easily adapted to other countries by inserting population-specific epidemiological data, and to future changes in cancer incidence, stage distribution and fractionation recommendations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

Auchter, Richard M.; Scholtens, Denise; Adak, Sudeshna; Wagner, Henry; Cella, David F.; Mehta, Minesh P.

2001-01-01

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

Consideration of margins for hypo fractionated radiotherapy

International Nuclear Information System (INIS)

Herschtal, A.; Foroudi, F.; Kron, T.

2010-01-01

Full text: Geographical misses of the tumour are of concern in radiotherapy and are typically accommodated by introducing margins around the target. However, there is a trade-off between ensuring the target receives sufficient dose and minimising the dose to surrounding normal structures. Several methods of determining margin width have been developed with the most commonly used one proposed by M. VanHerk (VanHerk UROBP 52: 1407, 2002). VanHerk's model sets margins to achieve 95% of dose coverage for the target in 90% of patients. However, this model was derived assuming an infinite number of fractions. The aim of the present work is to estimate the modifications necessary to the model if a finite number of fractions are given. Software simulations were used to determine the true probability of a patient achieving 95% target coverage if different fraction numbers are used for a given margin width. Model parameters were informed by a large data set recently acquired at our institution using daily image guidance for prostate cancer patients with implanted fiducial markers. Assuming a 3 mm penumbral width it was found that using the VanHerk model only 74 or 54% of patients receive 95% of the prescription dose if 20 or 6 fractions are given, respectively. The steep dose gradients afforded by IMRT are likely to make consideration of the effects of hypofractionation more important. It is necessary to increase the margins around the target to ensure adequate tumour coverage if hypofractionated radiotherapy is to be used for cancer treatment. (author)

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

International Nuclear Information System (INIS)

Kagei, K.; Shirato, H.; Suzuki, K.; Isu, T.; Sawamura, Y.; Sakamoto, T.; Fukuda, S.; Nishioka, T.; Hashimoto, S.; Miyasaka, K.

1999-01-01

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.)

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

International Nuclear Information System (INIS)

Amano, Kosuke; Ikeda, Hiroko; Chigusa, Satoshi; Tanaka, Masahiro; Katayama, Hirofumi; Takeda, Koji

2014-01-01

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)

Role of fractionated radiotherapy in patients with hemangioma of the cavernous sinus

International Nuclear Information System (INIS)

Park, Sun Min; Yoon, Sang Min; Lee, Su Min; Park, Jin Hong; Song, Si Yeol; Lee, Sang Wook; Ahn, Seung Do; Kim, Jong Hoon; Choi, Eun Kyung

2017-01-01

We performed this retrospective study to investigate the outcomes of patients with hemangioma of the cavernous sinus after fractionated radiotherapy. We analyzed 10 patients with hemangioma of the cavernous sinus who were treated with conventional radiotherapy between January 2000 and December 2016. The median patient age was 54 years (range, 31–65 years), and 8 patients (80.0%) were female. The mean hemangioma volume was 34.1 cm"3 (range, 6.8–83.2 cm"3), and fractionated radiation was administered to a total dose of 50–54 Gy with a daily dose of 2 Gy. The median follow-up period was 6.8 years (range, 2.2–8.8 years). At last follow-up, the volume of the tumor had decreased in all patients. The average tumor volume reduction rate from the initial volume was 72.9% (range, 18.9–95.3%). All 10 of the cranial neuropathies observed before radiation therapy had improved, with complete symptomatic remission in 9 cases (90%) and partial remission in 1 case (10%). No new acute neurologic impairments were reported after radiotherapy. One probable compressive optic neuropathy was observed at 1 year after radiotherapy. Fractionated radiotherapy achieves both symptomatic and radiologic improvements. It is a well-tolerated treatment modality for hemangiomas of the cavernous sinus

Role of fractionated radiotherapy in patients with hemangioma of the cavernous sinus

Energy Technology Data Exchange (ETDEWEB)

Park, Sun Min; Yoon, Sang Min; Lee, Su Min; Park, Jin Hong; Song, Si Yeol; Lee, Sang Wook; Ahn, Seung Do; Kim, Jong Hoon; Choi, Eun Kyung [Dept. of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2017-09-15

We performed this retrospective study to investigate the outcomes of patients with hemangioma of the cavernous sinus after fractionated radiotherapy. We analyzed 10 patients with hemangioma of the cavernous sinus who were treated with conventional radiotherapy between January 2000 and December 2016. The median patient age was 54 years (range, 31–65 years), and 8 patients (80.0%) were female. The mean hemangioma volume was 34.1 cm{sup 3} (range, 6.8–83.2 cm{sup 3}), and fractionated radiation was administered to a total dose of 50–54 Gy with a daily dose of 2 Gy. The median follow-up period was 6.8 years (range, 2.2–8.8 years). At last follow-up, the volume of the tumor had decreased in all patients. The average tumor volume reduction rate from the initial volume was 72.9% (range, 18.9–95.3%). All 10 of the cranial neuropathies observed before radiation therapy had improved, with complete symptomatic remission in 9 cases (90%) and partial remission in 1 case (10%). No new acute neurologic impairments were reported after radiotherapy. One probable compressive optic neuropathy was observed at 1 year after radiotherapy. Fractionated radiotherapy achieves both symptomatic and radiologic improvements. It is a well-tolerated treatment modality for hemangiomas of the cavernous sinus.

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

International Nuclear Information System (INIS)

Zachariah, B.; Jacob, S.S.; Gwede, C.; Cantor, A.; Patil, J.; Casey, L.; Zachariah, A.B.

2001-01-01

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

Hypo fractionated radiotherapy in advanced lung cancer

International Nuclear Information System (INIS)

Andrade Carvalho, Heloisa de; Saito, Newton Heitetsu; Gomes, Herbeni Cardoso; Aguilar, Patricia Bailao; Nadalin, Wladimir

1996-01-01

Patients with advanced lung cancers have bad prognosis and, many times, are submitted to prolonged and not always efficient treatments. We present a study where 51 patients were treated with hypo fractionated radiotherapy, based on two distinct schemes, according to the performance status and social conditions of each patient: continuous treatment: 30 Gy, 10 fractions of 3 Gy, 5 days/week (37 cases); weekly treatment: 30 Gy, 6 fractions of 5 Gy, once a week (14 cases). Symptoms relief and impact in survival were evaluated. In both groups, we observed improvement of symptoms in about 70% of the occurrences with a medium survival of three months. We conclude that hypo fractionation is an effective palliative treatment for lung cancers, in patients with short life-expectancy and must be considered as a option in advanced cases, in patients with short life-expectancy that deserve some kind of treatment. (author). 37 refs., 2 tabs

Optimization of fractionated radiotherapy of tumors

International Nuclear Information System (INIS)

Ivanov, V.K.

1984-01-01

Underlying modern conceptions of clinical radiobiology and mathematic methods in system theory a model of radiation therapy for tumors is developed. To obtain optimal fractionating conditions the principle of gradual optimization is used. A optimal therapeutic method permits to minimize the survival of a tumor cell population with localized lesions of the intact tissue. An analytic research is carried out for the simplest variant of the model. By help of a SORT-program unit the conditions are ascertained for gradual optimization of radiotherapy. (author)

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

International Nuclear Information System (INIS)

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

2015-01-01

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 (R 2 = 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

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

International Nuclear Information System (INIS)

Denman, David L.; Levin, Rebecca; Buncher, C. Ralph; Aron, Bernard S.

1996-01-01

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 60 Co 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

Accelerated Hypofractionated Radiotherapy for Early-Stage Non-Small-Cell Lung Cancer: Long-Term Results

International Nuclear Information System (INIS)

Soliman, Hany; Cheung, Patrick; Yeung, Latifa; Poon, Ian; Balogh, Judith; Barbera, Lisa; Spayne, Jacqueline; Danjoux, Cyril; Dahele, Max; Ung, Yee

2011-01-01

Purpose: To retrospectively review the results of a single-institution series of accelerated hypofractionated radiotherapy for early-stage non-small-cell lung cancer (NSCLC) in patients who are medically inoperable or who refuse surgery. Methods and Materials: Peripherally located T1 to T3 N0 M0 tumors were treated with 48 to 60 Gy in 12 to 15 fractions between 1996 and 2007. No elective nodal irradiation was delivered. Patient, tumor, and treatment information was abstracted from the medical records. Results: A total of 124 tumors were treated in 118 patients (56 male and 62 female). Median age at diagnosis was 76.3 years (range, 49-90 years). In all, 113 patients (95.8%) were not surgical candidates because of medical comorbidities. The 2- and 5-year overall survival (OS) rates were 51.0% and 23.3%, respectively, and the 2- and 5-year cause-specific survival (CSS) rates were 67.6% and 59.8%, respectively. The 2- and 5-year actuarial local control (LC) rates were 76.2% and 70.1%, respectively. Univariate analysis revealed that tumor size less than 3cm compared with greater than 3 cm resulted in significantly improved OS (40.0% vs. 5.0% at 5 years; p = 0.0002), CSS (69.7% vs. 45.1% at 5 years; p = 0.0461), and a trend toward better LC (82.5% vs. 66.9% at 2 years, 76.6% vs. 60.8% at 5 years; p = 0.0685). Treatment was well tolerated and there were no treatment delays because of acute toxicity. Conclusions: Accelerated hypofractionated radiotherapy with 48 to 60 Gy using fractions of 4 Gy per day provides very good results for small tumors in medically inoperable patients with early-stage NSCLC.

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

International Nuclear Information System (INIS)

Gatti, M.; Bresciani, S.; Ponzone, R.; Panaia, R.; Salatino, A.; Stasi, M.; Gabriele, P.

2011-01-01

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

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

International Nuclear Information System (INIS)

Artemova, N.A.

2008-01-01

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)

Treatment of pituitary adenomas by fractionated stereotactic radiotherapy: A prospective study of 110 patients

International Nuclear Information System (INIS)

Colin, Philippe; Jovenin, Nicolas; Delemer, Brigitte; Caron, Jean; Grulet, Herve; Hecart, Annie-Claude; Lukas, Celine; Bazin, Arnaud; Bernard, Mary-Helene; Scherpereel, Bernard; Peruzzi, Philippe; Nakib, Iab; Redon, Charles; Rousseaux, Pascal

2005-01-01

Purpose: To optimize and reduce the toxicity of pituitary adenoma irradiation by assessing the feasibility and effectiveness of fractionated stereotactic radiotherapy (FSR). Methods and Materials: Between 1990 and 1999, 110 consecutive patients, 47 with a functioning adenoma, were treated according to a strategy of either early surgery and FSR (n = 89) or FSR only (n = 21). Of the 110 patients, 75 had persistent macroscopic tumor and 47 persistent hormonal secretions; 15 were treated in the prophylactic setting. The linear accelerator-delivered dose was 50.4 Gy (5 x 1.8 Gy weekly), with a 2-mm safety margin. Results: After a minimal follow-up of 48 months, only 1 patient had developed progression. Of the 110 patients, 27 (36%) had a complete tumor response, 67 (89.3%) had an objective tumor response, 20 (42%) had a hormonal complete response, and 47 (100%) had a hormonal objective tumor response. The proportion of patients without a complete tumor response, objective tumor response, complete hormonal response, and objective hormonal response was 85.1%, 62%, 83%, and 59.3% at 4 years and 49.3%, 9%, 59.3%, and 10.6% at 8 years, respectively. The sole unfavorable predictive factor was preoperative SSE >20 mm for tumor response (p = 0.01) and growth hormone adenoma for the hormonal response (p <0.001). No late complications, except for pituitary deficiency, were reported, with a probability of requiring hormonal replacement of 28.5% and 35% at 4 and 8 years, respectively. Nonfunctioning status was the sole unfavorable factor (p = 0.0016). Conclusions: Surgery plus FSR is safe and effective. FSR focused to the target volume seems more suitable than standard radiotherapy, and standard fractionation reduces the risk of optic neuropathy sometimes observed after single-dose radiosurgery. Therefore, FSR allows us to consider combined transrhinoseptal surgery and early radiotherapy, with a curative goal without patient selection

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

DEFF Research Database (Denmark)

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. M...

An original accelerated radiotherapy schedule in stage III to IV head and neck cancers. Results in a multicenter setting

Energy Technology Data Exchange (ETDEWEB)

Allal, A.S. [Geneva Univ. Hospital (Switzerland). Div. of Radiation Oncology; Monney, M.; Rosset, A.; Ozsahin, M. [Hopital Cantonal Universitaire, Lausanne (Switzerland). Inst. de Radiographie; Guillemin, C. [Cantonal Radiotherapy Department Sion (Switzerland)

2000-01-01

Background: Accelerated radiotherapy delivery has recently been shown to be effective in overcoming repopulation during fractionated radiotherapy. The therapeutic ratio may be particularly favorable for 5-week regimens. This study reports the feasibility and results of a particular accelerated schedule in Stage III to IV head and neck carcinomas used in a multicenter setting. Patients and Methods: Seventy-four patients with Stage III (26 patients) or IV (48 patients) head and neck carcinomas were treated with a 5-week accelerated schedule (69.9 to 69.8 Gy in 41 to 40 fractions over a period of 35 to 36 days). Treatment began with 20 Gy in 10 daily fractions to initial involved sites, followed by bi-fractionated radiotherapy (2x1.6 Gy to 1.66 Gy/day) to a larger head and neck volume. Thirty-six (49%) patients received induction chemotherapy (median 3 cycles, range 1 to 4 cycles). Results: Grade 3 or 4 (RTOG) confluent mucositis was observed in 57 patients (77%) and Grade 3 dysphagia in 33 patients (44%). Grade 3 or 4 (RTOG-EORTC) late complications were scored in 10.5% of cases. The 5-year actuarial locoregional control rate was 56% (95% CI: 42 to 71). The 5-year overall actuarial survival was 32% (95% CI: 18 to 46). Induction chemotherapy was not associated with a more favorable outcome. Conclusions: This study demonstrates the feasibility of this schedule in a multicenter setting. The oncologic results appear similar to those obtained by other accelerated regimens, while the rate of late complications seems acceptable. Five-week accelerated regimens warrant further evaluation, particularly in conjunction with concomitant chemotherapy, in the framework of prospective trials. (orig.) [German] Hintergrund: Die Wirksamkeit der akzelerierten Bestrahlung in bezug auf die Bewaeltigung der Tumorzellrepopulation waehrend einer Radiotherapie ist vor kurzem nachgewiesen worden. Das Verhaeltnis zwischen therapeutischem Effekt und Toxizitaet duerfte fuer fuenfwoechige Schemen

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

Science.gov (United States)

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

2016-02-27

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 non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV

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

International Nuclear Information System (INIS)

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

2016-01-01

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 non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV

Better compliance with hypofractionation vs. conventional fractionation in adjuvant breast cancer radiotherapy. Results of a single, institutional, retrospective study

International Nuclear Information System (INIS)

Rudat, Volker; Nour, Alaa; Hammoud, Mohamed; Abou Ghaida, Salam

2017-01-01

The aim of the study was to identify factors significantly associated with the occurrence of unintended treatment interruptions in adjuvant breast cancer radiotherapy. Patients treated with postoperative radiotherapy of the breast or chest wall between March 2014 and August 2016 were evaluated. The radiotherapy regimens and techniques applied were either conventional fractionation (CF; 28 daily fractions of 1.8 Gy or 25 fractions of 2.0 Gy) or hypofractionation (HF; 15 daily fractions of 2.67 Gy) with inverse planned intensity-modulated radiotherapy (IMRT) or three-dimensional planned conformal radiotherapy (3DCRT). Logistic regression analysis was used to identify factors associated with noncompliance. Noncompliance was defined as the missing of at least one scheduled radiotherapy fraction. In all, 19 of 140 (13.6%) patients treated with HF and 39 of 146 (26.7%) treated with CF experienced treatment interruptions. Of 23 factors tested, the fractionation regimen emerged as the only independent significant prognostic factor for noncompliance on multivariate analysis (CF; p = 0.007; odds ratio, 2.3; 95% confidence interval, 1.3-4.2). No statistically significant differences concerning the reasons for treatment interruptions could be detected between patients treated with CF or HF. HF is significantly associated with a better patient compliance with the prescribed radiotherapy schedule compared with CF. The data suggest that this finding is basically related to the shorter overall treatment time of HF. (orig.) [de

Experimental results and clinical implications of the four R's in fractionated radiotherapy

International Nuclear Information System (INIS)

Trott, K.R.; Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg

1982-01-01

Experimental and clinical data on the four R' in fractionated radiotherapy are reviewed. The clinical importance of redistribution has not been proven in the experiment yet. On reoxygenation no unequivocal data in human cancer exists and a lot of variability in rodent tumours. Repair and regeneration are the most important of the four R's in fractionated radiotherapy. The presented experimental and clinical evidence suggests a differential response between tumour and late responding normal tissues with regard to these two R's. Tumours appear to have, in general, a smaller capacity for repairing sublethal radiation damage but a higher capacity for repopulation than late responding normal tissues. (orig.)

Quality assurance protocol for linear accelerators used in radiotherapy

International Nuclear Information System (INIS)

Petkovska, Sonja

2012-01-01

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)

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

International Nuclear Information System (INIS)

Kaasa, Stein; Brenne, Elisabeth; Lund, Jo-Asmund; Fayers, Peter; Falkmer, Ursula; Holmberg, Matts; Lagerlund, Magnus; Bruland, Oivind

2006-01-01

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

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

International Nuclear Information System (INIS)

Bettington, Catherine S.; Bryant, Guy; Hickey, Brigid; Tripcony, Lee; Pratt, Gary; Fay, Michael

2013-01-01

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.

Hyperfractionation as an altered fractionation regimen in primary radiotherapy for squamous cell carcinoma of the larynx

International Nuclear Information System (INIS)

Krstevska, V.; Smichkoska, S.

2006-01-01

The aim of the study was to investigate the efficacy of hyperfractionation as altered fractionation treatment schedule in comparison with conventional fractionation in primary definitive radiotherapy for laryngeal squamous cell carcinoma. From March 1999 to December 2000, a group of 28 patients with previously untreated squamous cell carcinoma of the larynx were irradiated with conventional fractionation to to total doses of 66 to 70 Gy in 33 to 35 fraction/6.5 to 7 weeks, 2 Gy/fraction/day, 5 days/week. From January 2001 to June 2004, the other 27 patients with the same diagnosis, were treated prospectively with hyperfractionation receiving radiotherapy delivered at 1.2 Gy/fraction, twice daily, 5 days/week to 74.4 to 79.2 Gy/62 to fractions/6.2 to 7 weeks. Complete response rates after two mounts of radiotherapy completion were 78.6% (22 of 28) and 66.7% (18 of 27) in the conventional fractionation and hyperfractionation group, respectively (Fisher exact test; P=0.246). The two year loco-regional control rates were 61 .0%±18.1 (95% CI) in the conventional fractionation group and 45.0%±18.8 (95% CI) in the hyperfractionation group (long-rank test; P=0.075). Overall survival rate at two years was 71.0%±16.8 (95% CI) for the conventional group and 43.0%±18.7 (95% CI) for the hyperfractionation group (long- rank test; P=0.071). The absence of statistically significant differences either in loco-regional control or overall survival observed between the two treatment modalities suggested that hyperfractionation regimen was not more efficacious than conventionally fractionated radiotherapy for previously untreated carcinoma of the larynx.

Commercial Prospect of Hadronic Radiotherapy Using Ion Accelerator in Indonesia

International Nuclear Information System (INIS)

Kunto-Wiharto; N-Supriana; R-Susworo; G-Suyitno

2000-01-01

In order to anticipate the construction of accelerator based laboratory of which one of its applications is for radiotherapy of cancer patients at Research and Development Center for Advanced Technology belonging to National Nuclear Energy Agency, Yogyakarta, in the next 7th. Five Year Development Plan (Repelita VII), it is considered important to perform a study on its commercial prospect. It is found, through calculations based on the available data and realistic assumptions, that patients from neighboring countries are needed to make the operation of radiotherapy facility effective and efficient. (author)

Radiotherapy Dose Fractionation under Parameter Uncertainty

International Nuclear Information System (INIS)

Davison, Matt; Kim, Daero; Keller, Harald

2011-01-01

In radiotherapy, radiation is directed to damage a tumor while avoiding surrounding healthy tissue. Tradeoffs ensue because dose cannot be exactly shaped to the tumor. It is particularly important to ensure that sensitive biological structures near the tumor are not damaged more than a certain amount. Biological tissue is known to have a nonlinear response to incident radiation. The linear quadratic dose response model, which requires the specification of two clinically and experimentally observed response coefficients, is commonly used to model this effect. This model yields an optimization problem giving two different types of optimal dose sequences (fractionation schedules). Which fractionation schedule is preferred depends on the response coefficients. These coefficients are uncertainly known and may differ from patient to patient. Because of this not only the expected outcomes but also the uncertainty around these outcomes are important, and it might not be prudent to select the strategy with the best expected outcome.

Accelerated fractionation in cancers of the esophagus: a multivariate analysis on 102 patients

International Nuclear Information System (INIS)

Girinsky, T.; Marsiglia, H.; Auperin, A.

1995-01-01

Purpose: Clinical outcome of cancer of the esophagus treated with conventional fractionated radiotherapy is dismal. Locoregional recurrences remain a major unresolved issue. Although data are scarce, potential doubling times of the squamous cell carcinoma of the esophagus appear to be generally rather short. Accelerated fractionation was used to shorten the conventional overall treatment time by two and half weeks (38% reduction of the treatment time) to counteract possible tumor cell repopulation. Materials and Methods: 102 patients with cancer of the esophagus not submitted to surgery for medical reasons or because of extensive disease. (locoregional or metastases) were entered in the study between 1986 and 1993. There were 27T1, 36T2 and 39T3 tumors, 10% of which were already metastatic. 89% of the patients had a squamous cell carcinoma and 11% an adenocarcinoma. Loss of weight about superior or equal to 10% occurred in 39% of the patients. In 63% of the cases neoadjuvant chemotherapy was given prior to radiation treatment. Radiation treatment delivered a mean dose of 66 Gy (SE=6.4), median dose of 65 Gy. The mean overall treatment time was 32.6 days (SE=6.2), median 31 days. A concomitant boost was used during the basic wide field irradiation to accelerate treatment. Results: Acute toxicity was mainly esophageal. Esophagitis grade III was observed in 17% of the patients and lasted 2 to 3 weeks. Radiation treatment was temporarily stopped in 8% of the patients due to esophagitis and was usually resumed a week later. Previous chemotherapy did not seem to significantly increase the occurrence of esophagitis. Of 82 evaluable patients, 56% had complete tumor regression 2 to 4 months after radiation treatment. There was no strict correlation between response after chemotherapy and the subsequent response after radiotherapy. The actuarial 3-year cause specific survival rates for T1, T2, T3 are 34%, 18.5% and 5% respectively. The actuarial 3-year local control rates

Accelerated fractionation in cancers of the esophagus: a multivariate analysis on 102 patients

Energy Technology Data Exchange (ETDEWEB)

Girinsky, T; Marsiglia, H; Auperin, A

1995-07-01

Purpose: Clinical outcome of cancer of the esophagus treated with conventional fractionated radiotherapy is dismal. Locoregional recurrences remain a major unresolved issue. Although data are scarce, potential doubling times of the squamous cell carcinoma of the esophagus appear to be generally rather short. Accelerated fractionation was used to shorten the conventional overall treatment time by two and half weeks (38% reduction of the treatment time) to counteract possible tumor cell repopulation. Materials and Methods: 102 patients with cancer of the esophagus not submitted to surgery for medical reasons or because of extensive disease. (locoregional or metastases) were entered in the study between 1986 and 1993. There were 27T1, 36T2 and 39T3 tumors, 10% of which were already metastatic. 89% of the patients had a squamous cell carcinoma and 11% an adenocarcinoma. Loss of weight about superior or equal to 10% occurred in 39% of the patients. In 63% of the cases neoadjuvant chemotherapy was given prior to radiation treatment. Radiation treatment delivered a mean dose of 66 Gy (SE=6.4), median dose of 65 Gy. The mean overall treatment time was 32.6 days (SE=6.2), median 31 days. A concomitant boost was used during the basic wide field irradiation to accelerate treatment. Results: Acute toxicity was mainly esophageal. Esophagitis grade III was observed in 17% of the patients and lasted 2 to 3 weeks. Radiation treatment was temporarily stopped in 8% of the patients due to esophagitis and was usually resumed a week later. Previous chemotherapy did not seem to significantly increase the occurrence of esophagitis. Of 82 evaluable patients, 56% had complete tumor regression 2 to 4 months after radiation treatment. There was no strict correlation between response after chemotherapy and the subsequent response after radiotherapy. The actuarial 3-year cause specific survival rates for T1, T2, T3 are 34%, 18.5% and 5% respectively. The actuarial 3-year local control rates

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

Energy Technology Data Exchange (ETDEWEB)

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.

A randomised controlled trial to evaluate both the role and the optimal fractionation of radiotherapy in the conservative management of early breast cancer.

Science.gov (United States)

Spooner, D; Stocken, D D; Jordan, S; Bathers, S; Dunn, J A; Jevons, C; Dodson, L; Morrison, J M; Oates, G D; Grieve, R J

2012-12-01

Postoperative radiotherapy is routinely used in early breast cancer employing either 50 Gy in 25 daily fractions (long course) or 40 Gy in 15 daily fractions (short course). The role of radiotherapy and shorter fractionation regimens require validation. Patients with clinical stage I and II disease were randomised to receive immediate radiotherapy or delayed salvage treatment (no radiotherapy). Patients receiving radiotherapy were further randomised between long (50 Gy in 25 daily fractions) or short (40 Gy in 15 daily fractions) regimens. The primary outcome measure was time to first locoregional relapse. Reported results are at a median follow-up of 16.9 years (interquartile range 15.4-18.8). In total, 707 women were recruited between 1985 and 1992: median age 59 years (range 28-80), 68% postmenopausal, median tumour size 2.0 cm (range 0.12-8.0); 271 patients have relapsed: 110 radiotherapy, 161 no radiotherapy. The site of first relapse was locoregional158 (64%) and distant 87 (36%). There was an estimated 24% reduction in the risk of any competing event (local relapse, distant relapse or death) with radiotherapy (hazard ratio = 0.76; 95% confidence interval 0.65, 0.88). The benefit of radiotherapy treatment for all competing event types was statistically significant (X(Wald)(2) = 36.04, P < 0.001). Immediate radiotherapy reduced the risk of locoregional relapse by 62% (hazard ratio = 0.38; 95% confidence interval 0.27, 0.53), consistent across prognostic subgroups. No differences were seen between either radiotherapy fractionation schedules. This study confirmed better locoregional control for patients with early breast cancer receiving radiotherapy. A radiotherapy schedule of 40 Gy in 15 daily fractions is an efficient and effective regimen that is at least as good as the international conventional regimen of 50 Gy in 25 daily fractions. Copyright © 2012. Published by Elsevier Ltd.

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

Energy Technology Data Exchange (ETDEWEB)

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

What next in fractionated radiotherapy

International Nuclear Information System (INIS)

Fowler, J.F.

1984-01-01

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.)

Linear accelerator Dynaray-CH: a central component of the BBC radiotherapy system

International Nuclear Information System (INIS)

Vogt, H.

1983-01-01

The author describes the newly developed range of linear accelerators Dynaray-CH 4 to 20. These modern installations for radiotherapy are used to generate photon and electron beams. The accelerators employ the proven BBC control system PROCONTIC (registered trademark), innovatory systems for movement control and actual-value display as well as the new radiation monitor system. (Auth.)

Effectiveness of accelerated radiotherapy for patients with inoperable non-small cell lung cancer (NSCLC) and borderline prognostic factors without distant metastasis: a retrospective review

International Nuclear Information System (INIS)

Nguyen, Linh N.; Komaki, Ritsuko; Allen, Pamela; Schea, Randi A.; Milas, Luka

1999-01-01

Purpose: The standard treatment for patients with unresectable or medically inoperable non-small cell lung cancer (NSCLC) and good prognostic factors (e.g., weight loss [WL] ≤5% and Karnofsky performance status [KPS] ≥70) is induction chemotherapy followed by definitive radiotherapy to the primary site at 1.8-2.0 Gy per fraction with a total dose of 60-63 Gy to the target volume. Patients with poor prognostic factors usually receive radiotherapy alone, but the fractionation schedule and total dose have not been standardized. To attempt to optimize irradiation doses and schedule, we compared the effectiveness of accelerated radiotherapy (ACRT) alone to 45 Gy at 3 Gy per fraction with standard radiation therapy (STRT) of 60-66 Gy at 2 Gy per fraction in regard to tumor response, local control, distant metastasis, toxicity, and survival. Methods and Materials: Fifty-five patients treated with radiation for NSCLC at The University of Texas M. D. Anderson Cancer Center between 1990 and 1994 were identified. All 55 patients had node-positive, and no distant metastasis (N+, M0) of NSCLC. Two cohorts were identified. One cohort (26 patients) had borderline poor prognostic factors (KPS less than 70 but higher than 50, and/or WL of more than 5%) and was treated with radiotherapy alone to 45 Gy over 3 weeks at 3 Gy/fraction (ACRT). The second cohort (29 patients) had significantly better prognostic factors (KPS ≥70 and WL ≤5%) and was treated to 60-66 Gy over 6 to 6((1)/(2)) weeks at 2 Gy per fraction (STRT) during the same period. Results: In the first cohort treated by ACRT, the distribution of patients by AJCC stage was IIB 8%, IIIA 19%, and IIIB 73%. Sixty-two percent had KPS 5%. The maximum response rate as determined by chest X-ray was 60% among 45 of 55 patients who were evaluable for response: combined complete responses (20%) and partial responses (40%). Overall survival in these patients was 13% at 2 and 5 years, with a locoregional control rate of 42% and a

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

Energy Technology Data Exchange (ETDEWEB)

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

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

International Nuclear Information System (INIS)

Hauptman, Jason S.; Barkhoudarian, Garni; Safaee, Michael; Gorgulho, Alessandra; Tenn, Steven; Agazaryan, Nzhde; Selch, Michael; De Salles, Antonio A.F.

2012-01-01

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

P53 function influences the effect of fractionated radiotherapy on glioblastoma tumors

International Nuclear Information System (INIS)

Haas-Kogan, Daphne A.; Kogan, Scott S.; Yount, Garret; Hsu, Jennie; Haas, Martin; Deen, Dennis F.; Israel, Mark A.

1999-01-01

Purpose: Glioblastoma multiforme brain tumors (GM) are treated with a spectrum of fractionation regimens based on the clinical and anatomical characteristics of the tumor but rarely based on the molecular characteristics of the individual neoplasm. This study tests the hypothesis that the response of cell lines derived from GM to fractionated radiotherapy depends on the function of wild-type p53 (wt p53), a tumor suppressor gene frequently mutated in GM tumors. Methods and Materials: Isogenic derivatives of glioblastoma cells differing only in p53 function were prepared using a retroviral vector expressing a dominant negative mutant of p53 (mt p53). Radiation survival in vitro was quantitated using linear quadratic and repair-saturation mathematical models. Apoptosis was assayed by a terminal deoxynucleotide transferase-labeling technique and chromatin morphology. Results: We have previously reported the generation of isogenic GM cell lines differing only in p53 function. U87-175.4, lacking wt p53 function, had a significantly lower α/β value than U87-LUX.8, expressing functional wt p53, leading us to hypothesize that fractionated irradiation would preferentially spare GM cells harboring mt p53 compared with those expressing functional, wt p53. Survival curves following either 2.0 Gy or 3.5 Gy/fraction demonstrated that lack of functional wt p53 was associated with resistance to fractionated irradiation. Radiation-induced apoptosis could not account for the observed differences in clonogenic survival. Rather, our data suggested that a deficit in the G1-checkpoint contributed to increased resistance to fractionated irradiation of cells expressing mutant p53. Conclusions: The effect of fractionated radiotherapy in GM may depend on the function of the tumor suppressor gene p53. A potential clinical consequence of these findings is that hyperfractionation regimens may provide a therapeutic advantage specifically for tumors expressing wt p53 whereas a radiotherapy

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

Caravatta, Luciana; Padula, Gilbert D.A.; Macchia, Gabriella; Ferrandina, Gabriella; Bonomo, Pierluigi; Deodato, Francesco; Massaccesi, Mariangela; Mignogna, Samantha; Tambaro, Rosa; Rossi, Marco; Flocco, Mariano; Scapati, Andrea

2012-01-01

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.

Effects of fractionated stereotactic radiotherapy for primary hepatocellular carcinoma

International Nuclear Information System (INIS)

Choi, Byeong Ock; Jang, Hong Seok; Kang, Young Nam; Choi, Ihl Bhong; Kang, Ki Mun; Chai, Gyu Young; Lee, Sang Wook

2005-01-01

Reports on the outcome of curative radiotherapy for the primary hepatocellular carcinoma (HCC) are rarely encountered in the literature. In this study, we report our experience of a clinical trial where fractionated stereotactic radiotherapy (SRT) was used in treating a primary HCC. A retrospective analysis was performed on 20 patients who had been histologically diagnosed as HCC and treated by fractionated SRT. The long diameter of tumor measured by CT was 2 ∼ 6.5 cm (average: 3.8 cm). A single dose of radiation used in fractionated SRT was 5 or 10 Gy; each dose was prescribed based on the planning target volume and normalized to 85 ∼ 99% isocenter dose. Patients were treated 3 ∼ 5 times per week for 2 weeks, with each receiving a total dose of 50 Gy (the median dose: 50 Gy). The follow up period was 3 ∼ 55 months (the median follow up period: 23 months). The response rate was 60% (12 patients), with 4 patients showing complete response (20%), 8 patients showing partial response (40%), and 8 patients showing stable disease (40%). The 1-year and 2-year survival rates were 70.0% and 43.1%, respectively,and the median survival time was 20 months. The 1-year and 2-year disease free survival rates were 65% and 32.5%, respectively, and the median disease-free survival rate was 19 months. Some acute complications of the treatment were noted as follows: dyspepsia in 12 patients (60%), nausea/emesis in 8 patients (40%), and transient liver function impairment in 6 patients (30%). However, there was no treatment related death. The study indicates that fractionated SRT is a relatively safe and effective method for treating primary HCC. Thus, fractionated SRT may be suggested as a local treatment for HCC of small lesion and containing a single lesion, when the patients are inoperable or operation is refused by the patients. We thought that fractionated SRT is a challenging treatment modality for the HCC

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

International Nuclear Information System (INIS)

Yang Chengliang; Wang Jianhua; Li Dingjie; Mao Ronghu; Li, X. Allen

2012-01-01

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 V 100 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 V 50.4 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)

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

Energy Technology Data Exchange (ETDEWEB)

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.

Novel applications of particle accelerators to radiotherapy

International Nuclear Information System (INIS)

Kreiner, A.J.; Burlon, A.A.; Universidad Nacional de San Martin, Villa Ballester

2002-01-01

Charged hadrons (protons and heavier ions) have very definite advantages over photons as far as radiotherapy applications are concerned. They allow for much better spatial dose localization due to their charge, relatively high mass and nature of the energy deposition process. In the frame of an attempt to promote the introduction of hadrontherapy in Argentina an external beam facility has been installed at our tandem accelerator TANDAR. The advantages of heavy ions can only be fully exploited for tumors of well defined localization. In certain types of malignancies, however, the region infiltrated by tumor cells is diffuse, with no sharp boundaries and with microscopic ramifications. In such cases (particularly in certain brain cancers) a more sophisticated scheme has been suggested called boron neutron capture therapy (BNCT). In this work, the use of the Tandar accelerator to produce neutrons for feasibility studies for BNCT through low-energy proton beams on a thick LiF target is being briefly described. Studies on the 13 C(d,n) reaction and a comparison with other neutron-producing reactions are also mentioned. Simulation work to optimize an accelerator-based neutron production target is discussed. A project is being prepared to develop a small proton accelerator in Argentina. Technical specifications of this machine are briefly discussed. (author)

Direct costs of radiotherapy for rectal cancer: a microcosting study.

Science.gov (United States)

Hanly, Paul; Céilleachair, Alan Ó; Skally, Máiréad; O'Neill, Ciaran; Sharp, Linda

2015-05-02

Radiotherapy provides significant benefits in terms of reducing risk of local recurrence and death from rectal cancer. Despite this, up-to-date cost estimates for radiotherapy are lacking, potentially inhibiting policy and decision-making. Our objective was to generate an up-to-date estimate of the cost of traditional radiotherapy for rectal cancer and model the impact of a range of potential efficiency improvements. Microcosting methods were used to estimate total direct radiotherapy costs for long- (assumed at 45-50 Gy in 25 daily fractions over a 5 week period) and short-courses (assumed at 25 Gy in 5 daily fractions over a one week period). Following interviews and on-site visits to radiotherapy departments in two designated cancer centers, a radiotherapy care pathway for a typical rectal cancer patient was developed. Total direct costs were derived by applying fixed and variable unit costs to resource use within each care phase. Costs included labor, capital, consumables and overheads. Sensitivity analyses were performed. Radiotherapy treatment was estimated to cost between €2,080 (5-fraction course) and €3,609 (25-fraction course) for an average patient in 2012. Costs were highest in the treatment planning phase for the short-course (€1,217; 58% of total costs), but highest in the radiation treatment phase for the long-course (€1,974: 60% of total costs). By simultaneously varying treatment time, capacity utilization rates and linear accelerator staff numbers, the base cost fell by 20% for 5-fractions: (€1,660) and 35% for 25-fractions: (€2,354). Traditional radiotherapy for rectal cancer is relatively inexpensive. Moreover, significant savings may be achievable through service organization and provision changes. These results suggest that a strong economic argument can be made for expanding the use of radiotherapy in rectal cancer treatment.

Effect of set up time on sublethal repair in multifield fractionated radiotherapy

International Nuclear Information System (INIS)

Kehwar, T.S.; Beriwal, Sushil; Sharma, S.C.

1998-01-01

The sublethal repair between two doses given with a variable time interval for mammalian cells in tissue culture was first demonstrated successfully by Elkind and Sutton. Subsequently on the basis of concept of sublethal damage repair between fractions, the radio therapists and radio biologists realized that dose can be increased by increasing the small size fractions. This concept is successfully being used in modern radiotherapy

Assessment of long-term quality of life of esophageal carcinoma patients treated with continuous accelerated hyperfractionated and late-course accelerated hyperfractionated radiotherapy

International Nuclear Information System (INIS)

Wang Yang; He Shaoqin; Shi Xuehui; Jiang Kaida; Yao Weiqiang; Wang Ying

2002-01-01

Objective: To compare the long-term quality of life in esophageal carcinoma patients treated with continuous accelerated hyperfractionated (CAHF) and late-course accelerated hyperfractionated (LCAF) radiotherapy. Methods: Subjective and Objective Management Analysis (SOMA) scale, Symptom Checklist 90 (SCL-90) and Life Satisfaction Index A (LSIA) questionnaire were mailed to the long survivors in both CAHF and LCAF groups to assess the long-term quality of life including symptoms, psychological status and life satisfaction. Results: There was no significant difference between the two groups in the score of quality of life such as late radiation reaction, SCL-90 and LSI-A. Conclusions: 1. It is reasonable to assess the quality of life with these scales for esophageal carcinoma patients treated with radiotherapy, 2. Preliminary results demonstrate that there is no significant difference in long-term quality of life between the CAHF and LCAF radiotherapy groups, 3. Methods of evaluating the long-term quality of life for esophageal carcinoma patients treated with radiotherapy needs further investigation, preferably involving more patients and setting on control arm

Doses to organs at cerebral risks: optimization by robotized stereotaxic radiotherapy and automatic segmentation atlas versus three dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Bondiau, P.Y.; Thariat, J.; Benezery, K.; Herault, J.; Dalmasso, C.; Marcie, S.; Malandain, G.

2007-01-01

The stereotaxic radiotherapy robotized by 'Cyberknife fourth generation' allows a dosimetric optimization with a high conformity index on the tumor and radiation doses limited on organs at risk. A cerebral automatic anatomic segmentation atlas of organs at risk are used in routine in three dimensions. This study evaluated the superiority of the stereotaxic radiotherapy in comparison with the three dimensional conformal radiotherapy on the preservation of organs at risk in regard of the delivered dose to tumors justifying an accelerated hypo fractionation and a dose escalation. This automatic segmentation atlas should allow to establish correlations between anatomy and cerebral dosimetry; This atlas allows to underline the dosimetry optimization by stereotaxic radiotherapy robotized for organs at risk. (N.C.)

Radiotherapy for breast cancer and pacemaker; Radiotherapie pour un cancer du sein et stimulateur cardiaque

Energy Technology Data Exchange (ETDEWEB)

Menard, J.; Campana, F.; Bollet, M.A.; Dendale, R.; Fournier-Bidoz, N.; Marchand, V.; Mazal, A.; Fourquet, A.; Kirova, Y.M. [Oncologie-radiotherapie, institut Curie, 26, rue d' Ulm, 75005 Paris (France); Kirov, K.M.; Esteve, M. [Departement d' anesthesie-reanimation-douleur, institut Curie, 75005 Paris (France)

2011-06-15

Purpose. - Patients with permanent cardiac pacemakers occasionally require radiotherapy. Therapeutic Irradiation may cause pacemakers to malfunction due to the effects of ionizing radiation or electromagnetic interference. We studied the breast cancer patients who needed breast and/or chest wall and lymph node irradiation to assess the feasibility and tolerance in this population of patients. Patients and methods. - From November 2008 to December 2009, more than 900 patients received radiotherapy for their breast cancer in our department using megavoltage linear accelerator (X 4-6 MV and electrons). Among them, seven patients were with permanent pacemaker. All patients have been treated to the breast and chest wall and/or lymph nodes. Total dose to breast and/or chest wall was 50 Gy/25 fractions and 46 Gy/23 fractions to lymph nodes. Patients who underwent conserving surgery followed by breast irradiation were boosted when indicated to tumour bed with 16 Gy/8 fractions. All patients were monitored everyday in presence of radiation oncologist to follow the function of their pacemaker. All pacemakers were controlled before and after radiotherapy by the patients' cardiologist. Results. - Seven patients were referred in our department for postoperative breast cancer radiotherapy. Among them, only one patient was declined for radiotherapy and underwent mastectomy without radiotherapy. In four cases the pacemaker was repositioned before the beginning of radiotherapy. Six patients, aged between 48 and 84 years underwent irradiation for their breast cancer. Four patients were treated with conserving surgery followed by breast radiotherapy and two with mastectomy followed by chest wall and internal mammary chain, supra- and infra-clavicular lymph node irradiation. The dose to the pacemaker generator was kept below 2 Gy. There was no pacemaker dysfunction observed during the radiotherapy. Conclusion. - The multidisciplinary work with position change of the pacemaker

TLD Intercomparison in accelerators for radiotherapy in three Latin american countries

International Nuclear Information System (INIS)

Gaona, E.; Azorin N, J.; Perez, M.A.; Picon, C.; Castellanos, E.; Plazas, M.C.; Murcia, G.; Archundia, L.

1998-01-01

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

Human normal tissue reactions in radiotherapy

International Nuclear Information System (INIS)

Taniike, Keiko

1990-01-01

Acute and late normal tissue reactions in radiotherapy have not been considered to be major problems with conventional fractionation. But they may cause certain problems when newer schedules such as hyperfractionation or accelerated fractionation are used. In opposing parallel radiotherapy, the dose fractionation of skin or subcutaneous connective tissue are different between in one portal and two portals daily. So we examined acute skin erythema and late connective tissue fibrosis in the two groups (one and two portals) of the patients with uterus cancer. Acute skin erythema and late connective tissue fibrosis were slightly stronger in case of one portal daily. In relation to the anatomical site of skin, acute skin erythema was stronger at the buttocks than the lower abdomen, but late fibrosis was reverse to that. So the degree of acute skin erythema did not predict the degree of late connective tissue fibrosis. The number of Time Dose Fractionation Factor could roughly estimate the degree of erythema and fibrosis. Late fibrosis in 36 fractions increased with an increase of abdominal thickness, but acute erythema did not. (author)

Single vs. multiple fraction regimens for palliative radiotherapy treatment of multiple myeloma. A prospective randomised study

International Nuclear Information System (INIS)

Rudzianskiene, Milda; Inciura, Arturas; Gerbutavicius, Rolandas; Rudzianskas, Viktoras; Dambrauskiene, Ruta; Juozaityte, Elona; Macas, Andrius; Simoliuniene, Renata; Kiavialaitis, Greta Emilia

2017-01-01

To compare the impact of a single fraction (8 Gy x 1 fraction) and multifraction (3 Gy x 10 fractions) radiotherapy regimens on pain relief, recalcification and the quality of life (QoL) in patients with bone destructions due to multiple myeloma (MM). In all, 101 patients were included in a randomised prospective clinical trial: 58 patients were included in the control arm (3 Gy x 10 fractions) and 43 patients into the experimental arm (8 Gy x 1 fraction). The response rate was defined according to the International Consensus on Palliative Radiotherapy criteria. Recalcification was evaluated with radiographs. QoL questionnaires were completed before and 4 weeks after treatment. Pain relief was obtained in 81/101 patients (80.2%): complete response in 56 (69%) and partial in 25 patients (30.9%). No significant differences were observed in analgesic response between the groups. Significant factors for pain relief were female gender, age under 65, IgG MM type, presence of recalcification at the irradiated site. Recalcification was found in 32/101 patients (33.7%): complete in 17 (53.2%) and partial in 15 (46.2%). No significant differences were observed in recalcification between the groups. Significant factors for recalcification were Karnofsky index ≥ 60%, haemoglobin level ≤ 80 g/dl, MM stage II and analgesic response at the irradiated site. The QoL after radiotherapy was improved in the control group. The same analgesic and recalcification response was observed using two different radiotherapy regimens. Higher doses should be used to achieve a better QoL. (orig.) [de

Fractionated stereotactic radiotherapy in the treatment of pituitary adenomas

International Nuclear Information System (INIS)

Kopp, C.; Theodorou, M.; Poullos, N.; Astner, S.T.; Geinitz, H.; Molls, M.; Stalla, G.K.; Meyer, B.; Nieder, C.; Tromsoe Univ.; Grosu, A.L

2013-01-01

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.)

Fractionated stereotactic radiotherapy in the treatment of pituitary adenomas

Energy Technology Data Exchange (ETDEWEB)

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.)

Laser-driven particle acceleration for radiobiology and radiotherapy: where we are and where we are going

Science.gov (United States)

Giulietti, Antonio

2017-05-01

Radiation therapy of tumors progresses continuously and so do devices, sharing a global market of about $ 4 billions, growing at an annual rate exceeding 5%. Most of the progress involves tumor targeting, multi-beam irradiation, reduction of damage on healthy tissues and critical organs, dose fractioning. This fast-evolving scenario is the moving benchmark for the progress of the laser-based accelerators towards clinical uses. As for electrons, both energy and dose requested by radiotherapy are available with plasma accelerators driven by lasers in the power range of tens of TW but several issues have still to be faced before getting a prototype device for clinical tests. They include capability of varying electron energy, stability of the process, reliability for medical users. On the other side hadron therapy, presently applied to a small fraction of cases but within an exponential growth, is a primary option for the future. With such a strong motivation, research on laser-based proton/ion acceleration has been supported in the last decade in order to get performances suitable to clinical standards. None of these performances has been achieved so far with laser techniques. In the meantime a rich crop of data have been obtained in radiobiological experiments performed with beams of particles produced with laser techniques. It is quite significant however that most of the experiments have been performed moving bio samples to laser labs, rather moving laser equipment to bio labs or clinical contexts. This give us the measure that laser community cannot so far provide practical devices usable by non-laser people.

Fractionated brain stereotactic radiotherapy: assessment of repositioning precision using a thermoforming mask

International Nuclear Information System (INIS)

Barret, A.; Champeaux-Orange, E.; Bouscayrol, H.; Wachter, T.

2011-01-01

The authors report a study which aimed at assessing the patient repositioning precision obtained with a support system used during a brain fractionated stereotactic radiotherapy and comprising a thermoforming mask (Elektra head mask). The repositioning is assessed by means of scano-graphies and superimposition with the stereotactic frame. A three-dimensional vector has been computed for each patient. The average displacement corresponds to that published in literature. The high quality of the support system allows a non invasive brain stereotactic radiotherapy to be performed which is also comfortable for the patient. Short communication

Modified optimal fractionation for poor prognosis malignant gliomas: An elusive search

International Nuclear Information System (INIS)

Gupta, Tejpal; Dinshaw, Ketayun

2005-01-01

The prognosis of malignant gliomas has not changed much over the last few decades despite refinements in neurosurgical techniques, high-precision radiotherapy, and newer chemotherapeutic agents. The median survival of poor prognosis malignant gliomas (older and/or poor performance status patients) still remains in the range of 6-9 months following maximal safe resection and postoperative conventionally fractionated adjuvant radiotherapy with or without chemotherapy. However, six weeks of daily radiotherapy does seem inappropriate in relation to the short expected survival time in this subset and there is an increasing emphasis on reducing the overall treatment time and the number of hospital visits by such patients. This can be achieved either by accelerated radiotherapy or by hypofractionated radiation, both of which are equivalent to conventional fractionation in terms of palliative effect and survival, as in discussed in this review. Despite enough evidence, such alteration of fractionation has not gained widespread acceptance by the oncologic fraternity. This review has been conducted to collate the evidence that could help shift the paradigm from conventional to modified fractionation in poor prognosis malignant glioma patients

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

Directory of Open Access Journals (Sweden)

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

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

International Nuclear Information System (INIS)

Pedicini, Piernicola; Fiorentino, Alba; Improta, Giuseppina; Storto, Giovanni; Benassi, Marcello; Orecchia, Roberto; Salvatore, Marco; Nappi, Antonio; Strigari, Lidia; Alicia Jereczek-Fossa, Barbara; Alterio, Daniela; Cremonesi, Marta; Botta, Francesca; Vischioni, Barbara; Caivano, Rocchina

2012-01-01

To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr) and the reduction of the effective doubling time (T D ) 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 T D 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 (H EGFr and L EGFr ), respectively. By obtaining the T D from the above analysis and the sub-sites’ potential doubling time (T pot ) from flow cytometry and immunohistochemical methods, we were able to estimate the average T D for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (D prolif ), was estimated. The averages of T D were 77 (27-90) 95% days in L EGFr and 8.8 (7.3-11.0) 95% days in H EGFr , if an onset of accelerated proliferation T K at day 21 was assumed. The correspondent H EGFr sub-sites’ T D 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 T pot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The D prolif for the H EGFr 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 T D and D prolif for each head and neck sub-site

Neurosymptomatic carvenous sinus meningioma: a 15-years experience with fractionated stereotactic radiotherapy and radiosurgery

International Nuclear Information System (INIS)

Correa, Sebastião Francisco Miranda; Marta, Gustavo Nader; Teixeira, Manoel Jacobsen

2014-01-01

The tumor removal of Cavernous Sinus Meningiomas usually results in severe neurological deficits. Stereotactic radiosurgery (SRS) and fractionated Stereotactic radiotherapy (SRT) are advanced modalities of radiotherapy for treatment of patients with inoperable and symptomatic CSMs. The authors evaluated the long term symptomatology, the image findings, and the toxicity of patients with CSMs treated with SRS or SRT. From 1994 to 2009, 89 patients with symptomatic CSMs were treated with SRS or SRT. The indication was based on tumour volume and or proximity to the optic chiasm. The median single dose of SRS was 14 Gy, while the SRT total dose, ranged from 50.4 to 54 Gy fractionated in 1.8-2 Gy/dose. The median follow-up period lasted 73 months. The clinical and radiological improvement was the same despite the method of radiotherapy; 41.6% (SRS) and 48.3% (SRT) of patients treated. The disease-free survivals were 98.8%, 92.3% and 92.3%, in 5, 10, and 15 years, respectively. There was no statistical difference in relation to the symptoms and image findings between both methods. According to the Common Toxicity Criteria, 7% of the patients presented transient optic neuropathy during 3 months (grade 2) and recovered with dexamethasone, 2 patients had trigeminal neuropathy (grade 2) and improved rapidly, and one patient presented total occlusion of the internal carotid artery without neurological deficit (grade 2). Temporary lethargy and headache (grade 1) were the most frequent immediate complications. No severe complications occurred. Stereotactic Radiosurgery and fractionated Stereotactic Radiotherapy were equally safe and effective in the management of symptomatic CSMs

Accelerated Fractional Ventilation Imaging with Hyperpolarized Gas MRI

Science.gov (United States)

Emami, Kiarash; Xu, Yinan; Hamedani, Hooman; Profka, Harrilla; Kadlecek, Stephen; Xin, Yi; Ishii, Masaru; Rizi, Rahim R.

2013-01-01

PURPOSE To investigate the utility of accelerated imaging to enhance multi-breath fractional ventilation (r) measurement accuracy using HP gas MRI. Undersampling shortens the breath-hold time, thereby reducing the O2-induced signal decay and allows subjects to maintain a more physiologically relevant breathing pattern. Additionally it may improve r estimation accuracy by reducing RF destruction of HP gas. METHODS Image acceleration was achieved by using an 8-channel phased array coil. Undersampled image acquisition was simulated in a series of ventilation images and images were reconstructed for various matrix sizes (48–128) using GRAPPA. Parallel accelerated r imaging was also performed on five mechanically ventilated pigs. RESULTS Optimal acceleration factor was fairly invariable (2.0–2.2×) over the range of simulated resolutions. Estimation accuracy progressively improved with higher resolutions (39–51% error reduction). In vivo r values were not significantly different between the two methods: 0.27±0.09, 0.35±0.06, 0.40±0.04 (standard) versus 0.23±0.05, 0.34±0.03, 0.37±0.02 (accelerated); for anterior, medial and posterior slices, respectively, whereas the corresponding vertical r gradients were significant (P fractional ventilation measurement with HP gas MRI. PMID:23400938

Radiotherapy for breast cancer and pacemaker

International Nuclear Information System (INIS)

Menard, J.; Campana, F.; Bollet, M.A.; Dendale, R.; Fournier-Bidoz, N.; Marchand, V.; Mazal, A.; Fourquet, A.; Kirova, Y.M.; Kirov, K.M.; Esteve, M.

2011-01-01

Purpose. - Patients with permanent cardiac pacemakers occasionally require radiotherapy. Therapeutic Irradiation may cause pacemakers to malfunction due to the effects of ionizing radiation or electromagnetic interference. We studied the breast cancer patients who needed breast and/or chest wall and lymph node irradiation to assess the feasibility and tolerance in this population of patients. Patients and methods. - From November 2008 to December 2009, more than 900 patients received radiotherapy for their breast cancer in our department using megavoltage linear accelerator (X 4-6 MV and electrons). Among them, seven patients were with permanent pacemaker. All patients have been treated to the breast and chest wall and/or lymph nodes. Total dose to breast and/or chest wall was 50 Gy/25 fractions and 46 Gy/23 fractions to lymph nodes. Patients who underwent conserving surgery followed by breast irradiation were boosted when indicated to tumour bed with 16 Gy/8 fractions. All patients were monitored everyday in presence of radiation oncologist to follow the function of their pacemaker. All pacemakers were controlled before and after radiotherapy by the patients' cardiologist. Results. - Seven patients were referred in our department for postoperative breast cancer radiotherapy. Among them, only one patient was declined for radiotherapy and underwent mastectomy without radiotherapy. In four cases the pacemaker was repositioned before the beginning of radiotherapy. Six patients, aged between 48 and 84 years underwent irradiation for their breast cancer. Four patients were treated with conserving surgery followed by breast radiotherapy and two with mastectomy followed by chest wall and internal mammary chain, supra- and infra-clavicular lymph node irradiation. The dose to the pacemaker generator was kept below 2 Gy. There was no pacemaker dysfunction observed during the radiotherapy. Conclusion. - The multidisciplinary work with position change of the pacemaker before

Multiple daily fractionation in radiotherapy: biological rationale and preliminary clinical experiences

Energy Technology Data Exchange (ETDEWEB)

Arcangeli, G [Instituto Medico Scientifico, Rome (Italy). Dept. of Oncology; Mauro, F; Morelli, D; Nervi, C

1979-09-01

The biological bases of radiation dose fractionation are reviewed and discussed with special emphasis on reassortment. Experimental data on animal model systems are presented to clarify that reassortment has to be added to sublethal damage repair and reoxygenation in the rationale for an optimized radiotherapy course according to tumor cell kinetics. Clinical results on several human tumors treated with twice or thrice daily fractions are described. These results show that some clinically radioresistant tumors (especially if not characterized by a relatively long clinical doubling line) can be satisfactorily dealt with using multiple daily fractionation. Clinical observations indicate that a relatively high cumulative daily dose (200 + 150 + 150 rad) can be safely administered.

Palliative radiotherapy for lung cancer: two versus five fractions

Energy Technology Data Exchange (ETDEWEB)

Rees, G.J.G.; Devrell, C.E.; Barley, V.L.; Newman, H.F.V. [Bristol Oncology Centre (United Kingdom)

1997-09-01

The aim of this prospective randomized trial was to compare the symptomatic effects of two different regimens of palliative radiotherapy for lung cancer. Two hundred and sixteen patients needing palliation were randomized to receive either a 17 Gy mid-point dose in two fractions 1 week apart or 22.5 gy in five daily fractions. Both toxicity and efficacy were evaluated by postal questionnaires. This small study was intended to identify any clinically important differences in toxicity of efficacy between the two regimens. We detected no such difference, although there was a tendency for iatrogentic dysphagia and improvement in chest pain and cough to be more common with the two fraction regimen. The only symptom that was improved in over 50% for 8 or more was haemoptysis. Haemoptysis and chest pain appeared to be the best indications for treatment. The relief of other symptoms was disappointing in both degree and duration. (author).

Acute tumor vascular effects following fractionated radiotherapy in human lung cancer: In vivo whole tumor assessment using volumetric perfusion computed tomography

International Nuclear Information System (INIS)

Ng, Q.-S.; Goh, Vicky; Milner, Jessica; Padhani, Anwar R.; Saunders, Michele I.; Hoskin, Peter J.

2007-01-01

Purpose: To quantitatively assess the in vivo acute vascular effects of fractionated radiotherapy for human non-small-cell lung cancer using volumetric perfusion computed tomography (CT). Methods and Materials: Sixteen patients with advanced non-small-cell lung cancer, undergoing palliative radiotherapy delivering 27 Gy in 6 fractions over 3 weeks, were scanned before treatment, and after the second (9 Gy), fourth (18 Gy), and sixth (27 Gy) radiation fraction. Using 16-detector CT, multiple sequential volumetric acquisitions were acquired after intravenous contrast agent injection. Measurements of vascular blood volume and permeability for the whole tumor volume were obtained. Vascular changes at the tumor periphery and center were also measured. Results: At baseline, lung tumor vascularity was spatially heterogeneous with the tumor rim showing a higher vascular blood volume and permeability than the center. After the second, fourth, and sixth fractions of radiotherapy, vascular blood volume increased by 31.6% (paired t test, p = 0.10), 49.3% (p = 0.034), and 44.6% (p = 0.0012) respectively at the tumor rim, and 16.4% (p = 0.29), 19.9% (p = 0.029), and 4.0% (p = 0.0050) respectively at the center of the tumor. After the second, fourth, and sixth fractions of radiotherapy, vessel permeability increased by 18.4% (p = 0.022), 44.8% (p = 0.0048), and 20.5% (p = 0.25) at the tumor rim. The increase in permeability at the tumor center was not significant after radiotherapy. Conclusion: Fractionated radiotherapy increases tumor vascular blood volume and permeability in human non-small-cell lung cancer. We have established the spatial distribution of vascular changes after radiotherapy; greater vascular changes were demonstrated at the tumor rim compared with the center

Design and analysis of fractional order seismic transducer for displacement and acceleration measurements

Science.gov (United States)

Veeraian, Parthasarathi; Gandhi, Uma; Mangalanathan, Umapathy

2018-04-01

Seismic transducers are widely used for measurement of displacement, velocity, and acceleration. This paper presents the design of seismic transducer in the fractional domain for the measurement of displacement and acceleration. The fractional order transfer function for seismic displacement and acceleration transducer are derived using Grünwald-Letnikov derivative. Frequency response analysis of fractional order seismic displacement transducer (FOSDT) and fractional order seismic acceleration transducer (FOSAT) are carried out for different damping ratio with the different fractional order, and the maximum dynamic measurement range is identified. The results demonstrate that fractional order seismic transducer has increased dynamic measurement range and less phase distortion as compared to the conventional seismic transducer even with a lower damping ratio. Time response of FOSDT and FOSAT are derived analytically in terms of Mittag-Leffler function, the effect of fractional behavior in the time domain is evaluated from the impulse and step response. The fractional order system is found to have significantly reduced overshoot as compared to the conventional transducer. The fractional order seismic transducer design proposed in this paper is illustrated with a design example for FOSDT and FOSAT. Finally, an electrical equivalent of FOSDT and FOSAT is considered, and its frequency response is found to be in close agreement with the proposed fractional order seismic transducer.

WE-G-BRD-09: Novel MRI Compatible Electron Accelerator for MRI-Linac Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Whelan, B; Keall, P [University of Sydney, Sydney (Australia); Gierman, S; Schmerge, J [SLAC National Accelerator Laboratory, Palo Alto, CA (United States); Holloway, L [Ingham Institute, Sydney, NSW (Australia); Fahrig, R [Stanford University, Stanford, CA (United States)

2015-06-15

Purpose: MRI guided radiotherapy is a rapidly growing field; however current linacs are not designed to operate in MRI fringe fields. As such, current MRI- Linac systems require magnetic shielding, impairing MR image quality and system flexibility. Here, we present a bespoke electron accelerator concept with robust operation in in-line magnetic fields. Methods: For in-line MRI-Linac systems, electron gun performance is the major constraint on accelerator performance. To overcome this, we propose placing a cathode directly within the first accelerating cavity. Such a configuration is used extensively in high energy particle physics, but not previously for radiotherapy. Benchmarked computational modelling (CST, Darmstadt, Germany) was employed to design and assess a 5.5 cell side coupled accelerator with a temperature limited thermionic cathode in the first accelerating cell. This simulation was coupled to magnetic fields from a 1T MRI model to assess robustness in magnetic fields for Source to Isocenter Distance between 1 and 2 meters. Performance was compared to a conventional electron gun based system in the same magnetic field. Results: A temperature limited cathode (work function 1.8eV, temperature 1245K, emission constant 60A/K/cm{sup 2}) will emit a mean current density of 24mA/mm{sup 2} (Richardson’s Law). We modeled a circular cathode with radius 2mm and mean current 300mA. Capture efficiency of the device was 43%, resulting in target current of 130 mA. The electron beam had a FWHM of 0.2mm, and mean energy of 5.9MeV (interquartile spread of 0.1MeV). Such an electron beam is suitable for radiotherapy, comparing favourably to conventional systems. This model was robust to operation the MRI fringe field, with a maximum current loss of 6% compared to 85% for the conventional system. Conclusion: The bespoke electron accelerator is robust to operation in in-line magnetic fields. This will enable MRI-Linacs with no accelerator magnetic shielding, and minimise

The hypo-fractionated radiotherapy in the treatment of the prostate cancer: Radiate less to treat more

International Nuclear Information System (INIS)

Boissier, R.; Gross, E.

2012-01-01

The principle of the hypo-fractionation in radiotherapy is to deliver a higher dose by session and to reduce the duration of treatment. In the particular case of the cancer of prostate, a hypo-fractionated protocol allows to deliver an equivalent radiobiological dose identical even higher than a standard plan of irradiation. The hypo-fractionation is presented as a solution to improve the access to the care (fewer processing times by patient, more patients treated by machine) while increasing the quality of the care: better carcinological control, less radiotoxicity. The objective of this article is to make a clarification on the hypo-fractionated radiotherapy in first intention in the treatment of the localized prostate cancer. We count three studies on large cohorts, comparing standard plans to 1.8 2 Gy/session and hypo-fractionated plans (2.5 3 Gy/session). The inferior carcinological results of the two first comparative studies with regard to the study of phase I/II of the Cleveland clinic were owed to a sub-dosage of hypo-fractionated plans. The administered equivalent biological doses were lower than the at present recommended total doses and lower than the theoretical doses, calculated on the bases of an erroneous evaluation of the radio-sensibility of the prostate cancer. In the comparative study of Arcangeli, the rate of survival without biological recurrence in 4 years (82%) was significantly to the advantage of the hypo-fractionated group, while reducing the duration of treatment of 3 weeks. Four comparative studies reported acute/late toxicity, gastrointestinal (GI)/genito-urinary acceptable (GU) even lower with a hypo-fractionated plan. The hypo-fractionation is potentially the future of the radiotherapy in the treatment of the localized prostate cancer thanks to the technological innovation, but for all that does not constitute at present a standard. (authors)

Particle Acceleration and Fractional Transport in Turbulent Reconnection

Science.gov (United States)

Isliker, Heinz; Pisokas, Theophilos; Vlahos, Loukas; Anastasiadis, Anastasios

2017-11-01

We consider a large-scale environment of turbulent reconnection that is fragmented into a number of randomly distributed unstable current sheets (UCSs), and we statistically analyze the acceleration of particles within this environment. We address two important cases of acceleration mechanisms when particles interact with the UCS: (a) electric field acceleration and (b) acceleration by reflection at contracting islands. Electrons and ions are accelerated very efficiently, attaining an energy distribution of power-law shape with an index 1-2, depending on the acceleration mechanism. The transport coefficients in energy space are estimated from test-particle simulation data, and we show that the classical Fokker-Planck (FP) equation fails to reproduce the simulation results when the transport coefficients are inserted into it and it is solved numerically. The cause for this failure is that the particles perform Levy flights in energy space, while the distributions of the energy increments exhibit power-law tails. We then use the fractional transport equation (FTE) derived by Isliker et al., whose parameters and the order of the fractional derivatives are inferred from the simulation data, and solving the FTE numerically, we show that the FTE successfully reproduces the kinetic energy distribution of the test particles. We discuss in detail the analysis of the simulation data and the criteria that allow one to judge the appropriateness of either an FTE or a classical FP equation as a transport model.

Particle Acceleration and Fractional Transport in Turbulent Reconnection

Energy Technology Data Exchange (ETDEWEB)

Isliker, Heinz; Pisokas, Theophilos; Vlahos, Loukas [Department of Physics, Aristotle University of Thessaloniki, GR-52124 Thessaloniki (Greece); Anastasiadis, Anastasios [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15236 Penteli (Greece)

2017-11-01

We consider a large-scale environment of turbulent reconnection that is fragmented into a number of randomly distributed unstable current sheets (UCSs), and we statistically analyze the acceleration of particles within this environment. We address two important cases of acceleration mechanisms when particles interact with the UCS: (a) electric field acceleration and (b) acceleration by reflection at contracting islands. Electrons and ions are accelerated very efficiently, attaining an energy distribution of power-law shape with an index 1–2, depending on the acceleration mechanism. The transport coefficients in energy space are estimated from test-particle simulation data, and we show that the classical Fokker–Planck (FP) equation fails to reproduce the simulation results when the transport coefficients are inserted into it and it is solved numerically. The cause for this failure is that the particles perform Levy flights in energy space, while the distributions of the energy increments exhibit power-law tails. We then use the fractional transport equation (FTE) derived by Isliker et al., whose parameters and the order of the fractional derivatives are inferred from the simulation data, and solving the FTE numerically, we show that the FTE successfully reproduces the kinetic energy distribution of the test particles. We discuss in detail the analysis of the simulation data and the criteria that allow one to judge the appropriateness of either an FTE or a classical FP equation as a transport model.

Fractionated Stereotactic Radiotherapy in the Treatment of Vestibular Schwannoma (Acoustic Neuroma): Predicting the Risk of Hydrocephalus

International Nuclear Information System (INIS)

Powell, Ceri; Micallef, Caroline; Gonsalves, Adam; Wharram, Bev; Ashley, Sue; Brada, Michael

2011-01-01

Purpose: To determine the incidence and predictive factors for the development of hydrocephalus in patients with acoustic neuromas (AN) treated with fractionated stereotactic radiotherapy. Patients and Methods: Seventy-two patients with AN were treated with fractionated stereotactic radiotherapy between 1998 and 2007 (45-50 Gy in 25-30 fractions over 5 to 6 weeks). The pretreatment MRI scan was assessed for tumor characteristics and anatomic distortion independently of subsequent outcome and correlated with the risk of hydrocephalus. Results: At a median follow-up of 49 months (range, 1-120 months), 5-year event-free survival was 95%. Eight patients (11%) developed hydrocephalus within 19 months of radiotherapy, which was successfully treated. On univariate analysis, pretreatment factors predictive of hydrocephalus were maximum diameter (p = 0.005), proximity to midline (p = 0.009), displacement of the fourth ventricle (p = 0.02), partial effacement of the fourth ventricle (p < 0.001), contact with the medulla (p = 0.005), and more brainstem structures (p = 0.004). On multivariate analysis, after adjusting for fourth ventricular effacement, no other variables remained independently associated with hydrocephalus formation. Conclusions: Fractionated stereotactic radiotherapy results in excellent tumor control of AN, albeit with a risk of developing hydrocephalus. Patients at high risk, identified as those with larger tumors with partial effacement of the fourth ventricle before treatment, should be monitored more closely during follow-up. It would also be preferable to offer treatment to patients with progressive AN while the risk of hydrocephalus is low, before the development of marked distortion of fourth ventricle before tumor diameter significantly exceeds 2 cm.

Radiobiology of hypofractionated stereotactic radiotherapy: what are the optimal fractionation schedules?

International Nuclear Information System (INIS)

Shibamoto, Yuta; Miyakawa, Akifumi; Otsuka, Shinya; Iwata, Hiromitsu

2016-01-01

In hypofractionated stereotactic radiotherapy (SRT), high doses per fraction are usually used and the dose delivery pattern is different from that of conventional radiation. The daily dose is usually given intermittently over a longer time compared with conventional radiotherapy. During prolonged radiation delivery, sublethal damage repair takes place, leading to the decreased effect of radiation. In in vivo tumors, however, this decrease in effect may be counterbalanced by rapid reoxygenation. Another issue related to hypofractionated SRT is the mathematical model for dose evaluation and conversion. The linear–quadratic (LQ) model and biologically effective dose (BED) have been suggested to be incorrect when used for hypofractionation. The LQ model overestimates the effect of high fractional doses of radiation. BED is particularly incorrect when used for tumor responses in vivo, since it does not take reoxygenation into account. Correction of the errors, estimated at 5–20%, associated with the use of BED is necessary when it is used for SRT. High fractional doses have been reported to exhibit effects against tumor vasculature and enhance host immunity, leading to increased antitumor effects. This may be an interesting topic that should be further investigated. Radioresistance of hypoxic tumor cells is more problematic in hypofractionated SRT, so trials of hypoxia-targeted agents are encouraged in the future. In this review, the radiobiological characteristics of hypofractionated SRT are summarized, and based on the considerations, we would like to recommend 60 Gy in eight fractions delivered three times a week for lung tumors larger than 2 cm in diameter

On the Detectability of Acoustic Waves Induced Following Irradiation by a Radiotherapy Linear Accelerator.

Science.gov (United States)

Hickling, Susannah; Leger, Pierre; El Naqa, Issam

2016-02-11

Irradiating an object with a megavoltage photon beam generated by a clinical radiotherapy linear accelerator (linac) induces acoustic waves through the photoacoustic effect. The detection and characterization of such acoustic waves has potential applications in radiation therapy dosimetry. The purpose of this work was to gain insight into the properties of such acoustic waves by simulating and experimentally detecting them in a well-defined system consisting of a metal block suspended in a water tank. A novel simulation workflow was developed by combining radiotherapy Monte Carlo and acoustic wave transport simulation techniques. Different set-up parameters such as photon beam energy, metal block depth, metal block width, and metal block material were varied, and the simulated and experimental acoustic waveforms showed the same relative amplitude trends and frequency variations for such setup changes. The simulation platform developed in this work can easily be extended to other irradiation situations, and will be an invaluable tool for developing a radiotherapy dosimetry system based on the detection of the acoustic waves induced following linear accelerator irradiation.

Dose characteristics of in-house-built collimators for stereotactic radiotherapy with a linear accelerator

International Nuclear Information System (INIS)

Norrgaard, F. Stefan E.; Kulmala, Jarmo A.J.; Minn, Heikki R.I.; Sipilae, Petri M.

1998-01-01

Dose characteristics of a stereotactic radiotherapy unit based on a standard Varian Clinac 4/100 4 MV linear accelerator, in-house-built Lipowitz collimators and the SMART stereotactic radiotherapy treatment planning software have been determined. Beam collimation is constituted from the standard collimators of the linear accelerator and a tertiary collimation consisting of a replaceable divergent Lipowitz collimator. Four collimators with isocentre diameters of 15, 25, 35 and 45 mm, respectively, were constructed. Beam characteristics were measured in air, acrylic or water with ionization chamber, photon diode, electron diode, diamond detector and film. Monte Carlo simulation was also applied. The radiation leakage under the collimators was less than 1% at 50 mm depth in water. Specific beam characteristics for each collimator were imported to SMART and dose planning with five non-coplanar converging 140 deg. arcs separated by 36 deg. angles was performed for treatment of a RANDO phantom. Dose verification was made with TLD and radiochromic film. The in-house-built collimators were found to be suitable for stereotactic radiotherapy and patient treatments with this system are in progress. (author)

Final report of a randomized trial on altered-fractionated radiotherapy in nasopharyngeal carcinoma prematurely terminated by significant increase in neurologic complications

International Nuclear Information System (INIS)

Teo, Peter Man Lung; Leung, Sing Fai; Chan, Anthony Tak Cheung; Leung, Thomas Wai Tong; Choi, Peter Ho Keung; Kwan, Wing Hong; Lee, Wai Yee; Chau, Ricky Ming Chun; Yu, Peter Kau Wing; Johnson, Philip James

2000-01-01

Purpose: The aim of the present study was to compare the survival, local control and complications of conventional/accelerated-hyperfractionated radiotherapy and conventional radiotherapy in nonmetastatic nasopharyngeal carcinoma (NPC). Methods and Materials: From February 1993 to October 1995, 159 patients with newly diagnosed nonmetastatic (M0) NPC with N0 or 4 cm or less N1 disease (Ho's N-stage classification, 1978) were randomized to receive either conventional radiotherapy (Arm I, n = 82) or conventional/accelerated-hyperfractionated radiotherapy (Arm II, n = 77). Stratification was according to the T stage. The biologic effective dose (10 Grays) to the primary and the upper cervical lymphatics were 75.0 and 73.1 for Arm I and 84.4 and 77.2 for Arm II, respectively. Results: With comparable distribution among the T stages between the two arms, the free from local failure rate at 5 years after radiotherapy was not significantly different between the two arms (85.3%; 95% confidence interval, 77.2-93.4% for Arm I; and 88.9%; 95% confidence interval, 81.7-96.2% for Arm II). The two arms were also comparable in overall survival, relapse-free survival, and rates of distant metastasis and regional relapse. Conventional/accelerated-hyperfractionated radiotherapy was associated with significantly increased radiation-induced damage to the central nervous system (including temporal lobe, cranial nerves, optic nerve/chiasma, and brainstem/spinal cord) in Arm II. Although insignificant, radiation-induced cranial nerve(s) palsy (typically involving VIII-XII), trismus, neck soft tissue fibrosis, and hypopituiturism and hypothyroidism occurred more often in Arm II. In addition, the complications occurred at significantly shorter intervals after radiotherapy in Arm II. Conclusion: Accelerated hyperfractionation when used in conjunction with a two-dimensional radiotherapy planning technique, in this case the Ho's technique, resulted in increased radiation damage to the central

A randomised trial of accelerated and conventional radiotherapy for stage III and IV squamous carcinoma of the head and neck: a Trans-Tasman Radiation Oncology Group Study

International Nuclear Information System (INIS)

Poulsen, Michael G.; Denham, James W.; Peters, Lester J.; Lamb, David S.; Spry, Nigel A.; Hindley, Andrew; Krawitz, Hedley; Hamilton, Chris; Keller, Jacqui; Tripcony, Lee; Walker, Quenten

2001-01-01

Purpose: The aims of this randomized controlled trial were to determine whether there were differences in the disease-free survival (DFS) and toxicity between conventional radiotherapy (CRT) and a continuous 3 week accelerated radiotherapy regimen (ART) in stage III and IV squamous cell carcinoma of the oral cavity, oropharynx, larynx and hypopharynx. Patients and methods: Patients from 14 centres throughout Australia and New Zealand were randomly assigned to either CRT, using a single 2 Gy/day to a dose of 70 Gy in 35 fractions in 49 days or to ART, using 1.8 Gy twice a day to a dose of 59.4 Gy in 33 fractions in 24 days. Treatment allocation was stratified for site and stage. The accrual began in 1991 and the trial was closed in 1998 when the target of 350 patients was reached. Results: The median potential follow-up time was 53 months (range, 14-101). The DFS at 5 years was 41% (95% CI, 33-50%) for ART and 35% (95% CI, 27-43%) for CRT (P=0.323) and the hazard ratio was 0.87 in favour of ART (95% CI, 0.66-1.15). The 5-year disease-specific survival rates were 40% for CRT and 46% for ART (P=0.398) and the loco-regional control was 47% for CRT vs. 52% for ART (P=0.300). The respective hazard ratios were 0.88 (95% CI, 0.65-1.2) and 0.85 (0.62-1.16), favouring the accelerated arm. In the ART arm, confluent mucositis was more severe (94 vs. 71%; P<0.001) and peaked about 3 weeks earlier than in the CRT arm, but healing appeared complete in all cases. There were statistically significant reductions in the probability of grade 2 or greater late soft tissue effects over time in the ART arm (P<0.05), except for the mucous membrane where late effects were similar in both arms. Conclusions: Differences in DFS, disease-specific survival and loco-regional control have not been demonstrated. ART resulted in more acute mucosal toxicity, but this did not result in greater prolongation of the treatment time compared with the CRT arm. There were less late effects in the ART arm

Gemcitabine, cisplatin, and hyperfractionated accelerated radiotherapy for locally advanced non-small cell lung cancer.

Science.gov (United States)

Zwitter, Matjaz; Kovac, Viljem; Smrdel, Uros; Strojan, Primoz

2006-09-01

Due to potent radiosensitization and potential serious or fatal toxicity, concurrent gemcitabine and irradiation should only be applied within clinical trials. We here present experience from a phase I-II clinical trial for patients with locally advanced non-small cell lung cancer (NSCLC) treated with hyperfractionated accelerated radiotherapy and concurrent low-dose gemcitabine. Eligible patients had locally advanced inoperable NSCLC without pleural effusion, Eastern Cooperative Oncology Group performance status 0-1, were chemotherapy naïve and had no previous radiotherapy to the chest, and had adequate hematopoietic, liver, and kidney function. Routine brain computed tomography was not performed, and positron emission tomography/computed tomography was not available. Treatment consisted of three parts: induction chemotherapy with gemcitabine and cisplatin in standard doses, local treatment with concurrent chemotherapy and radiotherapy, and consolidation chemotherapy. Patients were irradiated with opposed AP-PA and oblique fields, using 2.5-D treatment planning. Although corrections for inhomogeneous tissue were made, volume of total lung receiving > or =20 Gy (V20) could not be determined. The trial started as phase I, aimed to determine the dose-limiting toxicity and maximal tolerated dose (MTD) for concurrent hyperfractionated radiotherapy (1.4 Gy twice daily) and gemcitabine 55 mg/m twice weekly as a radiosensitizer. Phase II of the trial then continued at the level of MTD. Twenty-eight patients with NSCLC, nine patients with stage IIIA, 16 patients with IIIB, and three patients with an inoperable recurrence after previous surgery, entered the trial. The first 12 patients entered Phase I of the trial at the initial level of 42 Gy in 30 fractions in 3 weeks. Dose-limiting toxicity was acute esophagitis; 47.6 Gy in 34 fractions in 3.5 weeks was the MTD for this regimen of concurrent chemotherapy and radiotherapy. In phase II of the trial, this dose was applied

Results of different modes conformal radiotherapy in treatment of cervical cancer

International Nuclear Information System (INIS)

Baranovs'ka, L.M.; Yivankova, V.S.; Khrulenko, T.V.; Skomorokhova, T.V.; Gorelyina, G.L.

2017-01-01

Development of techniques for cytotoxic treatment applying different modes of conformal radiotherapy, brachytherapy and high-energy (high dose rate - HDR) is one of the promising areas of optimization and efficiency of conservative treatment of patients with regional forms of cervical cancer. At Radiation Oncology Department, National Cancer Institute, 89 patients with stage 2b-3b cervical cancer, aged 29 to 70, underwent examination and combined radiotherapy course. The patients were divided into 2 main groups (56 patients) depending on the mode of developed conformal radiation therapy, and a control group made up by 33 patients (classic, default conformal radiotherapy). Results. Along with external beam radiotherapy, the patients of Group 2 were provided with conformal radiotherapy carried out by means of the linear accelerator of electrons in the mode of enhanced multi fractionation of irradiation dose applied to the small pelvis area (tumor and lymph efflux channels) with the single tumor dose 1.3 Gy twice per day once 4-6 hours up to the total radiation dose of 45 Gy applied to the small pelvis lymph nodes. The patients of Group 1 and the ones of the control group underwent conformal radiotherapy in the mode of standard fractionation applied to the small pelvis area with the single tumor dose of 1.8 Gy up to the total radiation dose of 45 Gy. Conformal radiotherapy was carried out for the patients of Group 1 associated with chemoradiomodifiers (tegafur, cisplatin). At the stage 2 of combined radiotherapy course, all patients underwent HDR brachytherapy via Co60 source in the mode of the single tumor dose of 5 Gy at point A up to the total radiation dose of 35-40 Gy. Therefore, employing accelerated mode of multifractiation in conformal radiotherapy of patients with regional cervical cancer makes it possible to enhance canrcinocidal irradiation doses applied to a tumor, and an interval between radiotherapy fractions provides conditions for initiation of

Acute toxicity and cost analysis of a phase III randomized trial of accelerated and conventional radiotherapy for squamous carcinoma of the head and neck: a trans- tasman radiation oncology group study

International Nuclear Information System (INIS)

Poulsen, M.; Williamson, S.; Tripcony, L.; Spry, N.; Peters, L.; Penniment, M.; Lamb, D.; Krawitz, H.

1999-01-01

The primary purpose of the present analysis was to assess the feasibility and acute toxicity of a pure accelerated fractionation regimen in a cooperative group setting. This analysis included the first 320 patients entered on to the Trans-Tasman Radiation Oncology Group (TROG) randomized controlled trial which compared accelerated radiotherapy (ART) with conventional radiotherapy (CRT) in stage lIl and IV squamous cell carcinoma (SCC) of the head and neck. Patients were randomized to either 59.4 Gy in 33 fractions over 24 days (ART) or to 70 Gy 35 fractions over 49 days (CRT) after being stratified for site and stage. Accrual began in 1991 and the trial was closed on 3 April 1998 with the targeted 350 patients. The 3-year survival for the whole group was 54%, and the 3-year disease-free survival was 41%. Toxicity data were available on 303 patients (148 ART; 155 CRT). Mucosal toxicity was worse in the accelerated grup, and it peaked ∼ 3 weeks earlier than the conventional grup. Skin toxicity was equivalent but occurred ∼ 7 days earlier in the accelerated grup. Acute effects in both grups healed completely. Hospitalization was more common in the ART grup (71 vs 52 patients; P=0.01) but the total bed days in hospital was not greatly different (1707 bed days for ART and 1607 bed days for CRT). Patients were more likely to require nasogastric (NG) feeding in the ART grup (49 vs 33 patients; P = 0.02). There were 1157 NG feeding days for ART and 1154 NG feeding days for CRT. The average cost of radiation treatment per patient including hospitalisation, NG feeding and accommodation was $11 750 in the ART grup and $11 587 in the CRT grup. The accelerated grup has been shown to be a tolerable, practical and cost-equivalent regimen. The assessment of the therapeutic ratio of this accelerated protocol (ART) will be determined when the analysis of late effects and loco-regional control is made when the data are more mature. Copyright (1999) Blackwell Science Pty Ltd

Fractionated stereotaxic radiotherapy in the treatment of the retinoblastoma: preliminary results; Radiotherapie stereotaxique fractionnee dans le traitement du retinoblastome: resultats preliminaires

Energy Technology Data Exchange (ETDEWEB)

Pica, A. [Centre Hospitalier Universitaire Vaudois (CHUV), Service de Radiotherapie, Lausanne (Switzerland); Moeckli, R.; Do, H. [Institut de Radiophysique Appliquee, Lausanne (Switzerland); Balmer, A.; Munier, F. [Hopital ophtalmique Jules-Gonin, Lausanne (Switzerland); Chollet Rivier, M. [Centre Hospitalier Universitaire Vaudois (CHUV), Service d' Anesthesie, Lausanne (Switzerland)

2006-11-15

The objective of this study is to evaluate the impact in term of morbidity at short and long term and the response to the fractionated stereotaxic radiotherapy with a micro multi slides collimator in the treatment of the retinoblastoma. (N.C.)

Clinical outcome of stereotactic body radiotherapy of 54 Gy in nine fractions for patients with localized lung tumor using a custom-made immobilization system

International Nuclear Information System (INIS)

Aoki, Masahiko; Abe, Yoshinao; Kondo, Hidehiro

2007-01-01

The aim of this study was to investigate the clinical outcome of stereotactic body radiotherapy (SBRT) of 54 Gy in nine fractions for patients with localized lung tumor using a custom-made immobilization system. The subjects were 19 patients who had localized lung tumor (11 primaries, 8 metastases) between May 2003 and October 2005. Treatment was conducted on 19 lung tumors by fixed multiple noncoplanar conformal beams with a standard linear accelerator. The isocentric dose was 54 Gy in nine fractions. The median overall treatment time was 15 days (range 11-22 days). All patients were immobilized by a thermo-shell and a custom-made headrest during the treatment. The crude local tumor control rate was 95% during the follow-up of 9.4-39.5 (median 17.7) months. In-field recurrence was noted in only one patient at the last follow-up. The Kaplan-Meier overall survival rate at 2 years was 89.5%. Grade 1 radiation pneumonia and grade 1 radiation fibrosis were observed in 12 of the 19 patients. Treatment-related severe early and late complications were not observed in this series. The stereotactic body radiotherapy of 54 Gy in nine fractions achieved acceptable tumor control without any severe complications. The results suggest that SBRT can be one of the alternatives for patients with localized lung tumors. (author)

Single vs. multiple fraction regimens for palliative radiotherapy treatment of multiple myeloma. A prospective randomised study

Energy Technology Data Exchange (ETDEWEB)

Rudzianskiene, Milda; Inciura, Arturas; Gerbutavicius, Rolandas; Rudzianskas, Viktoras; Dambrauskiene, Ruta; Juozaityte, Elona [Lithuanian University of Health Sciences, Oncology Institute, Kaunas (Lithuania); Macas, Andrius [Lithuanian University of Health Sciences, Anaesthesiology Department, Kaunas (Lithuania); Simoliuniene, Renata [Lithuanian University of Health Sciences, Department of Physics, Mathematics and Biophysics, Kaunas (Lithuania); Kiavialaitis, Greta Emilia [University Hospital Zurich, Intitute of Anesthesiology, Zurich (Switzerland)

2017-09-15

To compare the impact of a single fraction (8 Gy x 1 fraction) and multifraction (3 Gy x 10 fractions) radiotherapy regimens on pain relief, recalcification and the quality of life (QoL) in patients with bone destructions due to multiple myeloma (MM). In all, 101 patients were included in a randomised prospective clinical trial: 58 patients were included in the control arm (3 Gy x 10 fractions) and 43 patients into the experimental arm (8 Gy x 1 fraction). The response rate was defined according to the International Consensus on Palliative Radiotherapy criteria. Recalcification was evaluated with radiographs. QoL questionnaires were completed before and 4 weeks after treatment. Pain relief was obtained in 81/101 patients (80.2%): complete response in 56 (69%) and partial in 25 patients (30.9%). No significant differences were observed in analgesic response between the groups. Significant factors for pain relief were female gender, age under 65, IgG MM type, presence of recalcification at the irradiated site. Recalcification was found in 32/101 patients (33.7%): complete in 17 (53.2%) and partial in 15 (46.2%). No significant differences were observed in recalcification between the groups. Significant factors for recalcification were Karnofsky index ≥ 60%, haemoglobin level ≤ 80 g/dl, MM stage II and analgesic response at the irradiated site. The QoL after radiotherapy was improved in the control group. The same analgesic and recalcification response was observed using two different radiotherapy regimens. Higher doses should be used to achieve a better QoL. (orig.) [German] Vergleich der einzeitigen vs. fraktionierten palliativen Radiotherapie in Bezug auf Schmerzlinderung, Knochenrekalzifizierung und Lebensqualitaet (QoL) bei Patienten mit multiplem Myelom (MM). In die randomisierte, prospektive Studie wurden 101 Patienten eingeschlossen: Die Kontrollgruppe (n = 58) erhielt eine fraktionierte (3 Gy x 10 Fraktionen) und die Experimentgruppe (n = 43) eine

Quantifying intra- and inter-fractional motion in breast radiotherapy

Energy Technology Data Exchange (ETDEWEB)

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.

Use of normalized total dose to represent the biological effect of fractionated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Flickinger, J C; Kalend, A [Pittsburgh University School of Medicine (USA). Department of Radiation Oncology Pittsburg Cancer Institute (USA)

1990-03-01

There are currently a number of radiobiological models to account for the effects of dose fractionation and time. Normalized total dose (NTD) is not another new model but is a previously reported, clinically useful form in which to represent the biological effect, determined by any specific radiobiological dose-fractionation model, of a course of radiation using a single set of standardized, easily understood terminology. The generalized form of NTD reviewed in this paper describes the effect of a course of radiotherapy administered with nonstandard fractionation as the total dose of radiation in Gy that could be administered with a given reference fractionation such as 2 Gy per fraction, 5 fractions per week that would produce an equivalent biological effect (probability of complications or tumor control) as predicted by a given dose-fractionation formula. The use of normalized total dose with several different exponential and linear-quadratic dose-fraction formulas is presented. (author). 51 refs.; 1 fig.; 1 tab.

Use of normalized total dose to represent the biological effect of fractionated radiotherapy

International Nuclear Information System (INIS)

Flickinger, J.C.; Kalend, A.

1990-01-01

There are currently a number of radiobiological models to account for the effects of dose fractionation and time. Normalized total dose (NTD) is not another new model but is a previously reported, clinically useful form in which to represent the biological effect, determined by any specific radiobiological dose-fractionation model, of a course of radiation using a single set of standardized, easily understood terminology. The generalized form of NTD reviewed in this paper describes the effect of a course of radiotherapy administered with nonstandard fractionation as the total dose of radiation in Gy that could be administered with a given reference fractionation such as 2 Gy per fraction, 5 fractions per week that would produce an equivalent biological effect (probability of complications or tumor control) as predicted by a given dose-fractionation formula. The use of normalized total dose with several different exponential and linear-quadratic dose-fraction formulas is presented. (author). 51 refs.; 1 fig.; 1 tab

Kimura's Disease of the Orbit Successfully Treated with Radiotherapy Alone: A Case Report

Directory of Open Access Journals (Sweden)

Yoshio Monzen

2014-03-01

Full Text Available We performed radiotherapy in a 28-year-old patient with Kimura's disease of the orbit. Irradiation with 21.6 Gy was administered to the tumor bed with a single dose of 1.8 Gy in 5 weekly fractions delivered via a high-energy linear accelerator (6-MV X-ray. Complete remission of the tumor and improvements in the neurological findings were achieved. Neither tumor regrowth nor late complications were detected up to 84 months after radiotherapy. Radiotherapy is an effective treatment for Kimura's disease of the orbit.

Accelerated hypofractionated radiation therapy (AHRT) for non-small-cell lung cancer: can we leave standard fractionation?

Science.gov (United States)

de Dios, N Rodríguez; Sanz, X; Foro, P; Membrive, I; Reig, A; Ortiz, A; Jiménez, R; Algara, M

2017-04-01

To report interim results from a single-institution study conducted to assess accelerated hypofractionated radiotherapy (AHRT) delivered with 3D conformal radiotherapy in two groups of patients with non-small cell lung cancer: (1) patients with early stage disease unable to tolerate surgery and ineligible for stereotactic body radiation therapy, and (2) patients with locally advanced disease unsuitable for concurrent chemoradiotherapy. A total of 83 patients (51 stage I-II, 32 stage III) were included. Radiotherapy targets included the primary tumor and positive mediastinal areas identified on the pre-treatment PET-CT. Mean age was 77.8 ± 7.8 years. ECOG performance status (PS) was ≥2 in 50.6 % of cases. Radiotherapy was delivered in daily fractions of 2.75 Gy to a total dose of 66 Gy (BED 10 84 Gy). Acute and late toxicities were evaluated according to NCI CTC criteria. At a median follow-up of 42 months, median overall survival (OS) and cause-specific survival (CSS) were 23 and 36 months, respectively. On the multivariate analysis, PS [HR 4.14, p = 0.0001)], stage [HR 2.51, p = 0.005)], and maximum standardized uptake values (SUVmax) [HR 1.04, p = 0.04)] were independent risk factors for OS. PS [HR 5.2, p = 0.0001)] and stage [HR 6.3, p = 0.0001)] were also associated with CSS. No cases of severe acute or late treatment-related toxicities were observed. OS and CSS rates in patients treated with AHRT for stage I-II and stage III NSCLC were good. Treatment was well tolerated with no grade three or higher treatment-related toxicity. PS, stage, and SUV max were predictive for OS and CSS.

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

International Nuclear Information System (INIS)

Dobrowsky, Werner; Dobrowsky, Eva; Wilson, George D.

2003-01-01

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/m 2 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

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

International Nuclear Information System (INIS)

Alfonso, Rodolfo; Martinez, William; Arelis, Lores; Morales, Jorge

2009-01-01

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)

Management of acoustic neuromas with fractionated stereotactic radiotherapy (FSRT): Long-term results in 106 patients treated in a single institution

International Nuclear Information System (INIS)

Combs, Stephanie E.; Volk, Sigrid; Schulz-Ertner, Daniela; Huber, Peter E.; Thilmann, Christoph; Debus, Juergen

2005-01-01

Purpose: To assess the long-term outcome and toxicity of fractionated stereotactic radiotherapy for acoustic neuromas in 106 patients treated in a single institution. Patients and Methods: Between October 1989 and January 2004, fractionated stereotactic radiotherapy (FSRT) was performed in 106 patients with acoustic neuroma (AN). The median total dose applied was 57.6 Gy in median single fractions of 1.8 Gy in five fractions per week. The median irradiated tumor volume was 3.9 mL (range, 2.7-30.7 mL). The median follow-up time was 48.5 months (range, 3-172 months). Results: Fractionated stereotactic radiotherapy was well tolerated in all patients. Actuarial local tumor control rates at 3- and 5- years after FSRT were 94.3% and 93%, respectively. Actuarial useful hearing preservation was 94% at 5 years. The presence of neurofibromatosis (NF-2) significantly adversely influenced hearing preservation in patients that presented with useful hearing at the initiation of RT (p = 0.00062). Actuarial hearing preservation without the diagnosis of NF-2 was 98%. In cases with NF-2, the hearing preservation rate was 64%. Cranial nerve toxicity other than hearing impairment was rare. The rate of radiation induced toxicity to the trigeminal and facial nerve was 3.4% and 2.3%, respectively. Conclusion: Fractionated stereotactic radiotherapy is safe and efficacious for the treatment of AN, with mild toxicity with regard to hearing loss and cranial nerve function. FSRT might be considered as an equieffective treatment modality compared to neurosurgery and therefore represents an interesting alternative therapy for patients with AN

Better compliance with hypofractionation vs. conventional fractionation in adjuvant breast cancer radiotherapy. Results of a single, institutional, retrospective study

Energy Technology Data Exchange (ETDEWEB)

Rudat, Volker; Nour, Alaa; Hammoud, Mohamed; Abou Ghaida, Salam [Saad Specialist Hospital, Department of Radiation Oncology, Al Khobar (Saudi Arabia)

2017-05-15

The aim of the study was to identify factors significantly associated with the occurrence of unintended treatment interruptions in adjuvant breast cancer radiotherapy. Patients treated with postoperative radiotherapy of the breast or chest wall between March 2014 and August 2016 were evaluated. The radiotherapy regimens and techniques applied were either conventional fractionation (CF; 28 daily fractions of 1.8 Gy or 25 fractions of 2.0 Gy) or hypofractionation (HF; 15 daily fractions of 2.67 Gy) with inverse planned intensity-modulated radiotherapy (IMRT) or three-dimensional planned conformal radiotherapy (3DCRT). Logistic regression analysis was used to identify factors associated with noncompliance. Noncompliance was defined as the missing of at least one scheduled radiotherapy fraction. In all, 19 of 140 (13.6%) patients treated with HF and 39 of 146 (26.7%) treated with CF experienced treatment interruptions. Of 23 factors tested, the fractionation regimen emerged as the only independent significant prognostic factor for noncompliance on multivariate analysis (CF; p = 0.007; odds ratio, 2.3; 95% confidence interval, 1.3-4.2). No statistically significant differences concerning the reasons for treatment interruptions could be detected between patients treated with CF or HF. HF is significantly associated with a better patient compliance with the prescribed radiotherapy schedule compared with CF. The data suggest that this finding is basically related to the shorter overall treatment time of HF. (orig.) [German] Ziel der Untersuchung war es, Faktoren zu identifizieren, die mit ungeplanten Behandlungsunterbrechungen bei der adjuvanten Strahlentherapie des Mammakarzinoms assoziiert sind. Es wurden Patienten untersucht, die eine adjuvante Strahlentherapie der Mamma oder Brustwand zwischen Maerz 2014 und August 2016 erhielten. Zur Anwendung kamen als Fraktionierungsprotokoll und strahlentherapeutische Technik eine konventionell fraktionierte (CF; 28 Fraktionen mit

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

Tada, Takuhito; Chiba, Yasutaka; Tsujino, Kayoko; Fukuda, Haruyuki; Nishimura, Yasumasa; Kokubo, Masaki; Negoro, Shunichi; Kudoh, Shinzoh; Fukuoka, Masahiro; Nakagawa, Kazuhiko; Nakanishi, Yoichi

2012-01-01

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 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 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.

Clinical investigation of twice-a-day fractionated radiotherapy for T2 laryngeal cancer

International Nuclear Information System (INIS)

Karasawa, K.; Kaneyasu, Y.; Fukuhara, N.; Kita-Okawa, M.; Okawa, T.

1996-01-01

Purpose/objective: To improve the local control rate while minimizing the complication rate in the treatment of T2 laryngeal cancer, we conducted a Phase II trial of twice-a-day fractionated radiotherapy (TDFR) and compared the results with those of historical control treated by conventional radiotherapy. Materials and Methods: Between 1966 and 1995, 126 cases with T2 laryngeal cancer were treated by radiotherapy in our department by Cobalt equipment. Median field sige was 42cm 2 . Since 1986, we started TDFR. Fifty-eight cases were treated by TDFR, among them there were 6 cases of supraglottic lesion, 49 cases of glottic, and 3 cases of subglottic. Their age ranged from 47 to 82 (mean 64), and all but 1 cases were male. They were irradiated with a fraction dose of 1.5 Gy twice a day at least 6 hours apart, 10 times a week to a total dosage of 66 - 78 Gy (mean 69Gy) in 30 to 53 days (median 43 days). Fifty-four (93 %) of the cases needed a split during radiotherapy for acute mucosal reaction. The other 68 cases were treated by conventional radiotherapy (control group). There were 8 cases of supraglottic lesion, 57 of glottic, and 3 of subglottic. Their age ranged from 33 to 86 (mean 62), and 62 cases (91 %) were male. They were irradiated with a fraction dose of 1.8 Gy (38 cases) or 2 Gy (30 cases) to a total dosage of 59 - 72Gy (mean 66 Gy) in 43 - 69 days (median 51 days). Thirteen (19 %) of the cases needed a split during radiotherapy. Acute and late reactions were graded into 4 grades and compared. Results: Five year actuarial local control rate was 79.0 % in the TDFR group and 75.6 % in the control group (n.s.). Five year actuarial survival rate was 79.7 % in the TDFR group and 77.7 % in the control group (n.s.). Five year actuarial cause-specific survival rate was 96.4 % in the TDFR group and 95.2 % in the control group (n.s.). Five year actuarial local control rate of glottic cases was 78.6 % in the TDFR group and 78.8 % in the control group (n.s.). As for

Effect of fractionated radiotherapy using a hypoxic cell radiosensitizer, RK-28, on experimental murine tumor

International Nuclear Information System (INIS)

Tanaka, Shukaku

1990-01-01

The effect of a hypoxic cell radiosensitizer RK-28, on fractionated radiotherapy was studied using mice with implanted tumors. Experimental animal tumors were third generation isoplants of a mammary carcinoma which arose spontaneously in a C 3 H/He mouse. RK-28 was given to the mice at two dosages: 0.4 mg/g,b.wt. and 0.2 mg/g.b.wt. Total dose of irradiation was 20 Gy which was divided into the first 10 Gy irradiation and the second 10 Gy performed after a proper time interval such as 1, 24, 48 and 72 hours after the first 10 Gy irradiation. Tumor growth was evaluated by TGT 50 /3 times, which was defined as the time required for 50% of the tumors to regrow to the 3 times value of its initial volume. Tumor volume was measured every day and TGT 50 /3 times was calculated by logit analysis method. No significant differences were found in the TGT 50 /3 times among the groups treated by radiation alone, those treated by RK-administration alone and those without any treatment. TGT 50 value of control group without any treatment was 3.40 (days). TGT 50 value of another group treated by RK-28 alone was 3.46. and TGT 50 value of 20 Gy X-ray irradiation alone was 10.23. Under the fractionated X-ray irradiation alone, TGT 50 values of the various time interval such as 9, 14, 48 and 72 hours were 11.26, 10.42, 12.14 and 1.10. Under the combined treatment of the fractionated X-ray irradiation and RK-28 administration, TGT 50 values were 17.84, 16.42, 16.59 and 17.49. These TGT 50 /3 times values showed that RK-28 had a radiosensitizing effect when given with fractionated radiotherapy even at lower doses of RK-28 administration and radiation. Therefore, it was suggested that fractionated radiotherapy using RK-28 was useful in the cancer treatment. (author) 52 refs

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

International Nuclear Information System (INIS)

Steinvorth, Sarah; Welzel, Grit; Fuss, Martin; Debus, Juergen; Wildermuth, Susanne; Wannenmacher, Michael; Wenz, Frederik

2003-01-01

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

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

International Nuclear Information System (INIS)

Cho, Jae Ho; Kim, Hyun Chang; Suh, Chang Ok

2005-01-01

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 ∼ 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∼ 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 (α / β = 10) and late-responding tissues (α /β = 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 3 and the risk of complication was assessed using serial multiple logistic regressions models. The associations between R-BED Gy 3 and rectal complications

Re-irradiation of recurrent anaplastic ependymoma using radiosurgery or fractionated stereotactic radiotherapy.

Science.gov (United States)

Murai, Taro; Sato, Kengo; Iwabuchi, Michio; Manabe, Yoshihiko; Ogino, Hiroyuki; Iwata, Hiromitsu; Tatewaki, Koshi; Yokota, Naoki; Ohta, Seiji; Shibamoto, Yuta

2016-03-01

Recurrent ependymomas were retreated with stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT). The efficacy, toxicities, and differences between SRS and FSRT were analyzed. Eight patients with recurrent ependymomas fulfilling the criteria described below were evaluated. Inclusion criteria were: (1) the patient had previously undergone surgery and conventional radiotherapy as first-line treatment; (2) targets were located in or adjacent to the eloquent area or were deep-seated; and (3) the previously irradiated volume overlapped the target lesion. FSRT was delivered to 18 lesions, SRS to 20 lesions. A median follow-up period was 23 months. The local control rate was 76 % at 3 years. No significant differences in local control were observed due to tumor size or fractionation schedule. Lesions receiving >25 Gy/5 fr or 21 Gy/3 fr did not recur within 1 year, whereas no dose-response relationship was observed in those treated with SRS. No grade ≥2 toxicity was observed. Our treatment protocol provided an acceptable LC rate and minimal toxicities. Because local recurrence of tumors may result in patient death, a minimum dose of 21 Gy/3 fr or 25 Gy/5 fr or higher may be most suitable for treatment of these cases.

Intestinal complications following accelerated fractionated X-irradiation

International Nuclear Information System (INIS)

Hauer-Jensen, M.; Poulakos, L.; Osborne, J.W.

1990-01-01

Due to paucity of suitable animal models, it has been difficult to study the development of long-term intestinal complications following fractionated irradiation. We recently developed a model which allows multiple radiation exposures of a short segment of rat ileum without the need for repeated surgery. In the present series, this model was used to study the influence of shortening the total treatment time (accelerated fractionation) on development of radiation enteropathy. Male rats were orchiectomized and a short segment of distal ileum was transposed to the scrotum. Starting 3 weeks after surgery, the scrotum containing the intestinal segment was X-irradiated with 20 fractions of 2.8 Gy (total dose 56 Gy). Two fractionation schedules were compared: one fraction per day (total treatment time 26 days) and 3 fractions per day (total treatment time 7 days). Actuarial survival curves were obtained, and the degree of radiation injury was assessed 2, 8 and 26 weeks after the last radiation exposure using a semiquantitative histopathologic scoring system. There was no mortality from acute radiation injury in either treatment group. All animals of the 1-fraction/day group survived the observation period (26 weeks). In the 3-fraction/day group, there was significant mortality due to intestinal obstruction, and cumulative mortality at 26 weeks was 100%. Radiation injury, as assessed by the histopathologic scoring system, was also more pronounced in this group than in the 1-fraction/day group. We conclude that shortening the total treatment time significantly increases the severity of late intestinal complications. Our data are suggestive of an association between acute mucosal damage and chronic radiation injury of the small intestine. (orig.)

Ultrashort courses of adjuvant breast radiotherapy: wave of the future or a fool's errand?

Science.gov (United States)

Khan, Atif J; Dale, Roger G; Arthur, Douglas W; Haffty, Bruce G; Todor, Dorin A; Vicini, Frank A

2012-04-15

In accelerated partial breast irradiation (APBI), the most commonly used fractionation schemes include 340 or 385 centigrays delivered in a twice daily administration. A further progression of the APBI literature has been the recent interest in extremely short courses of adjuvant radiotherapy, usually delivered by intraoperative radiotherapy techniques. This newer area of single-fraction radiotherapy approaches remains highly contentious. In particular, the recently reported TARGIT trial has been the subject of both praise and scorn, and a critical examination of the trial data and the underlying hypotheses is warranted. Short-term outcomes of the related Italian ELIOT approach have also been reported. Although the assumptions of linear quadratic formalism are likely to hold true in the range of 2 to 8 grays, equating different schedules beyond this range is problematic. A major problem of current single-fraction approaches is that the treatment doses are chosen empirically, or are based on tolerability, or on the physical dose delivery characteristics of the chosen technology rather than radiobiological rationale. This review article summarizes the current data on ultrashort courses of adjuvant breast radiotherapy and highlights both the promise and the potential pitfalls of the abbreviated treatment. Copyright © 2011 American Cancer Society.

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

DEFF Research Database (Denmark)

Grønborg, Caroline; Vestergaard, Anne; Høyer, Morten

2015-01-01

and to estimate population-based and patient-specific intra-fractional margins, also relevant for a future re-optimisation strategy. MATERIAL AND METHODS: Nine patients treated in a clinical phase II ART trial of daily plan selection for bladder cancer were included. In the library plans, 5 mm isotropic margins......BACKGROUND: The bladder is a tumour site well suited for adaptive radiotherapy (ART) due to large inter-fractional changes, but it also displays considerable intra-fractional motion. The aim of this study was to assess target coverage with a clinically applied method for plan selection ART...... were added to account for intra-fractional changes. Pre-treatment and weekly repeat magnetic resonance imaging (MRI) series were acquired in which a full three-dimensional (3D) volume was scanned every second min for 10 min (a total of 366 scans in 61 series). Initially, the bladder clinical target...

A survey of the practice and management of radiotherapy linear accelerator quality control in the UK.

Science.gov (United States)

Palmer, A; Kearton, J; Hayman, O

2012-11-01

The objective of this study was to determine current radiotherapy linear accelerator quality control (QC) practice in the UK, as a comparative benchmark and indicator of development needs, and to raise awareness of QC as a key performance indicator. All UK radiotherapy centres were invited to complete an online questionnaire regarding their local QC processes, and submit their QC schedules. The range of QC tests, frequency of measurements and acceptable tolerances in use across the UK were analysed, and consensus and range statistics determined. 72% of the UK's 62 radiotherapy centres completed the questionnaire and 40% provided their QC schedules. 60 separate QC tests were identified from the returned schedules. There was a large variation in the total time devoted to QC between centres: interquartile range from 13 to 26 h per linear accelerator per month. There has been a move from weekly to monthly testing of output calibration in the last decade, with reliance on daily constancy testing equipment. 33% of centres thought their schedules were in need of an update and only 30% used risk-assessment approaches to determine local QC schedule content. Less than 30% of centres regularly complete all planned QC tests each month, although 96% achieve over 80% of tests. A comprehensive "snapshot" of linear accelerator QC testing practice in the UK has been collated, which demonstrates reasonable agreement between centres in their stated QC test frequencies. However, intelligent design of QC schedules and management is necessary to ensure efficiency and appropriateness.

Fractionated stereotactically guided radiotherapy for pharmacoresistant epilepsy; Fraktionierte, stereotaktisch gefuehrte Radiotherapie der pharmakoresistenten Epilepsie

Energy Technology Data Exchange (ETDEWEB)

Grabenbauer, G.G.; Reinhold, C.; Lambrecht, U.; Sauer, R. [Klinik und Poliklinik fuer Strahlentherapie, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Kerling, F.; Pauli, E.; Stefan, H. [Neurologische Klinik, Abt. Epileptologie, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Mueller, R.G. [Inst. fuer Medizinische Physik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Ganslandt, O. [Neurochirurgische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany)

2003-01-01

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.) [German] Ziel: Diese prospektive Studie untersuchte die Effizienz einer fraktionierten stereotaktischen Radiotherapie (RT) bei therapieresistenter Temporallappenepilepsie. Patienten und Methoden: Einschlusskriterien waren Patienten im Alter von 17 bis 65 Jahren, die weder medikamentoes noch epilepsiechirurgisch anfallsfrei wurden und einen einseitigen Fokus aufwiesen. Zwei Patientenkohorten zu je sechs Patienten wurden zwischen 1997 und 1999 einer fraktionierten, stereotaktisch gefuehrten Radiotherapie mit 21 Gy (7 x 3 Gy) bzw. 30 Gy (15 x 2 Gy) unterzogen. Endpunkte der Untersuchung waren

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

Energy Technology Data Exchange (ETDEWEB)

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.)

Fractionated stereotactic conformal radiotherapy following conservative surgery in the control of craniopharyngiomas

International Nuclear Information System (INIS)

Minniti, Giuseppe; Saran, Frank; Traish, Daphne; Soomal, Rubin; Sardell, Susan; Gonsalves, Adam; Ashley, Susan; Warrington, Jim; Burke, Kevin; Mosleh-Shirazi, Amin; Brada, Michael

2007-01-01

Purpose: To describe the technique and results of stereotactically guided conformal radiotherapy (SCRT) in patients with craniopharyngioma after conservative surgery. Methods and materials: Thirty-nine patients with craniopharyngioma aged 3-68 years (median age 18 years) were treated with SCRT between June 1994 and January 2003. All patients were referred for radiotherapy after undergoing one or more surgical procedures. Treatment was delivered in 30-33 daily fractions over 6-6.5 weeks to a total dose of 50 Gy using 6 MV photons. Outcome was assessed prospectively. Results: At a median follow-up of 40 months (range 3-88 months) the 3- and 5-year progression-free survival (PFS) was 97% and 92%, and 3- and 5-year survival 100%. Two patients required further debulking surgery for progressive disease 8 and 41 months after radiotherapy. Twelve patients (30%) had acute clinical deterioration due to cystic enlargement of craniopharyngioma following SCRT and required cyst aspiration. One patient with severe visual impairment prior to radiotherapy had visual deterioration following SCRT. Seven out of 10 patients with a normal pituitary function before SCRT had no endocrine deficits following treatment. Conclusion: SCRT as a high-precision technique of localized RT is suitable for the treatment of incompletely excised craniopharyngioma. The local control, toxicity and survival outcomes are comparable to results reported following conventional external beam RT. Longer follow-up is required to assess long-term efficacy and toxicity, particularly in terms of potential reduction in treatment related late toxicity

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

International Nuclear Information System (INIS)

Droege, L.H.; Hinsche, T.; Hess, C.F.; Wolff, H.A.; Canis, M.; Alt-Epping, B.

2014-01-01

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.)

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

International Nuclear Information System (INIS)

Khalil, Azza A.; Bentzen, Soeren M.; Bernier, Jacques; Saunders, Michele I.; Horiot, Jean-Claude; Bogaert, Walter van den; Cummings, Bernard J.; Dische, Stanley

2003-01-01

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 D prolif 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

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

International Nuclear Information System (INIS)

Wui-Jin, Koh; Bergman, Kenneth S.; Rasey, Janet S.; Peterson, Lanell M.; Evans, Margaret L.; Graham, Michael M.; Grierson, John R.; Lindsley, Karen L.; Lewellen, Thomas K.; Krohn, Kenneth A.; Griffin, Thomas W.

1995-01-01

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

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

Directory of Open Access Journals (Sweden)

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.

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

International Nuclear Information System (INIS)

Couto, Henrique Lima; Amorim, Washington Cancado; Guimaraes, Rodrigo

2014-01-01

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)

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

International Nuclear Information System (INIS)

Elata, A.; Hassan, A. M. E.; Ali, E.; Calzolari, P.; Bettega, D.

2009-02-01

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 37o C 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 37o C 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)

Obstruction of the esophagus 5 months after radiotherapy for a central lung cancer

International Nuclear Information System (INIS)

Zips, D.; Baumann, M.; Herrmann, T.

2001-01-01

Dysphagia after radiotherapy of thoracic tumors may be caused by recurrences or by radiation damage to the esophagus. Case Report: A 75-year-old patient presented with a complete obstruction of the esophagus 5 months after CHARTWEL radiotherapy for a non-small cell lung cancer. During the last week of radiotherapy mild dysphagia (Grade 1 EORTC/RTOG, Grade 2 MRC-CHART-Score) occurred that persisted over the following months. X-ray and endoscopic investigations revealed an easily removable food bolus without evidence of esophageal stricture or ulceration. Conclusion: The case report describes a mild but prolonged early radiation reaction of the esophagus. In comparison with conventional fractionation the incidence of dysphagia is higher after accelerated fractionation schedules. The pathophysiologic mechanisms underlying persistent dysphagia are currently unknown. Beside of recurrences, radiation effects to the esophagus should be considered if dysphagia after irradiation of thoracic tumors occurs, because, as in this case, therapy may rapidly improve the symptoms. (orig.) [de

Present state of studies on FFAG accelerator for radiotherapy of cancer in National Institute of Radiological Sciences

International Nuclear Information System (INIS)

Misu, Toshiyuki

2003-01-01

From 2001, developmental contract studies with Ministry of Education, Culture, Sports, Science and Technology for a compact accelerator for heavy ion radiotherapy of cancer started in National Institute of Radiological Sciences (NIRS) with use of fixed field alternating gradient (FFAG) accelerator, which had been developed in High Energy Accelerator Research Organization (KEK). This paper describes the present state of those studies. Described are FFAG accelerator design for repeated acceleration for 200 Hz or more toward the carbon ion at 400 MeV/u with the range of 25 cm in water, FFAG optical systems for these purposes by linear analyses, and the present situation of the design. Technological problems yielded and future study plan are also commented. (N.I.)

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

International Nuclear Information System (INIS)

Boukerche, A.; Yahia, A.; Madouri, R.; Belmiloud, H.; Dali-Youcef, A.F.

2011-01-01

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

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

Science.gov (United States)

Dröge, L H; Hinsche, T; Canis, M; Alt-Epping, B; Hess, C F; Wolff, H A

2014-02-01

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.

Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

Energy Technology Data Exchange (ETDEWEB)

Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M. [Radiotherapy Centre West, The Hague (Netherlands); Molenaar, R. [Diaconessenhuis, Leiden (Netherlands). Dept. of Neurology; Lycklama a Nijeholt, G. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Radiology; Vecht, C. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Neurology; Struikmans, H. [Radiotherapy Centre West, The Hague (Netherlands); Leiden Univ. Medical Centre (Netherlands). Dept. of Radiotherapy; Kal, H.B.

2012-08-15

Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm{sup 3} or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

International Nuclear Information System (INIS)

Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M.; Molenaar, R.; Lycklama a Nijeholt, G.; Vecht, C.; Struikmans, H.; Leiden Univ. Medical Centre; Kal, H.B.

2012-01-01

Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm 3 or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

Tomotherapy – a different way of dose delivery in radiotherapy

Science.gov (United States)

Skórska, Małgorzata; Jodda, Agata; Ryczkowski, Adam; Kaźmierska, Joanna; Adamska, Krystyna; Karczewska-Dzionk, Aldona; Żmijewska-Tomczak, Małgorzata; Włodarczyk, Hanna

2012-01-01

Aim of the study Helical tomotherapy is one of the methods of radiotherapy. This method enables treatment implementation for a wide spectrum of clinical cases. The vast array of therapeutic uses of helical tomotherapy results directly from the method of dose delivery, which is significantly different from the classic method developed for conventional linear accelerators. The paper discusses the method of dose delivery by a tomotherapy machine. Moreover, an analysis and presentation of treatment plans was performed in order to show the therapeutic possibilities of the applied technology. Dose distributions were obtained for anaplastic medulloblastoma, multifocal metastases to brain, vulva cancer, tongue cancer, metastases to bones, and advanced skin cancer. Tomotherapy treatment plans were compared with conventional linear accelerator plans. Results Following the comparative analysis of tomotherapy and conventional linear accelerator plans, in each case we obtained the increase in dose distribution conformity manifested in greater homogeneity of doses in the radiation target area for anaplastic medulloblastoma, multifocal metastases to brain, vulva cancer, metastases to bones, and advanced skin cancer, and the reduction of doses in organs at risk (OAR) for anaplastic medulloblastoma, vulva cancer, tongue cancer, and advanced skin cancer. The time of treatment delivery in the case of a tomotherapy machine is comparable to the implementation of the plan prepared in intensity-modulated radiotherapy (IMRT) technique for a conventional linear accelerator. In the case of tomotherapy the application of a fractional dose was carried out in each case during one working period of the machine. For a conventional linear accelerator the total value of the fractional dose in the case of anaplastic medulloblastoma and metastases to bones was delivered using several treatment plans, for which a change of set-up was necessary during a fraction. Conclusion The obtained results

Radiotherapy for pain management of bone metastases

Energy Technology Data Exchange (ETDEWEB)

Rezende Junior, Ismar de; Mattos, Marcos Duarte de; Nakamura, Ricardo; Lemes Junior, Joaquim; Vanzelli, Talita Lozano, E-mail: rezende.med@terra.com.br [Radioterapia do Hospital de Cancer de Barretos, SP (Brazil)

2011-07-01

Purpose: This is the first Brazilian study intended to evaluate the response of pain relief with radiotherapy in three different fractionation and the clinical differences in managing pain in patients with painful bone metastases. Methods: Prospective study of patients with painful bone metastases referred to the Radiotherapy Sector of the Hospital de Cancer de Barretos for pain-relieving radiotherapy between March and December 2010. It is known that radiotherapy seems to alter the activation of osteoclast-mediated bone resorption, relieving pain in cases of painful bone metastases. Patients were assessed in relation to the status of pain intensity before and after the initiation of radiotherapy. Either a single fraction of 8Gy, five fractions of 4Gy or ten fractions of 3Gy were given. A visual analog scale (VAS) was applied by doctors, nurses and nursing technicians to assess pain intensity at each session of radiotherapy, and follow-up at 8, 30 and 90 days from the end of treatment. Results: We evaluated 92 consecutive patients, 48 male and 44 female, with a median age of 58 years. We found that 14% of patients referred from the Palliative Care or Clinical Oncology sectors need better pharmacological analgesia due to severe pain, compared with 40.5% of patients from the other sectors (p = 0.004). We also found that the onset of pain relief to patients receiving 10 fractions of 300cGy analgesia without changing the pre-radiotherapy analgesia occurred with significance after the fifth fraction. Improvement in pain experienced within 90 days of follow-up was found in eighty percent of patients, independent of fractionated radiotherapy, site of metastases and the clinical condition of the patient. Discussion/Conclusion: The Palliative Care and Clinical Oncology sectors expressed greater concern in regards to analgesia for the patient with painful bone metastases. Radiotherapy is an effective pain-relieving treatment in different fractionation studied, even though the

Radiotherapy for pain management of bone metastases

International Nuclear Information System (INIS)

Rezende Junior, Ismar de; Mattos, Marcos Duarte de; Nakamura, Ricardo; Lemes Junior, Joaquim; Vanzelli, Talita Lozano

2011-01-01

Purpose: This is the first Brazilian study intended to evaluate the response of pain relief with radiotherapy in three different fractionation and the clinical differences in managing pain in patients with painful bone metastases. Methods: Prospective study of patients with painful bone metastases referred to the Radiotherapy Sector of the Hospital de Cancer de Barretos for pain-relieving radiotherapy between March and December 2010. It is known that radiotherapy seems to alter the activation of osteoclast-mediated bone resorption, relieving pain in cases of painful bone metastases. Patients were assessed in relation to the status of pain intensity before and after the initiation of radiotherapy. Either a single fraction of 8Gy, five fractions of 4Gy or ten fractions of 3Gy were given. A visual analog scale (VAS) was applied by doctors, nurses and nursing technicians to assess pain intensity at each session of radiotherapy, and follow-up at 8, 30 and 90 days from the end of treatment. Results: We evaluated 92 consecutive patients, 48 male and 44 female, with a median age of 58 years. We found that 14% of patients referred from the Palliative Care or Clinical Oncology sectors need better pharmacological analgesia due to severe pain, compared with 40.5% of patients from the other sectors (p = 0.004). We also found that the onset of pain relief to patients receiving 10 fractions of 300cGy analgesia without changing the pre-radiotherapy analgesia occurred with significance after the fifth fraction. Improvement in pain experienced within 90 days of follow-up was found in eighty percent of patients, independent of fractionated radiotherapy, site of metastases and the clinical condition of the patient. Discussion/Conclusion: The Palliative Care and Clinical Oncology sectors expressed greater concern in regards to analgesia for the patient with painful bone metastases. Radiotherapy is an effective pain-relieving treatment in different fractionation studied, even though the

Carbon-ion radiotherapy for marginal lymph node recurrences of cervical cancer after definitive radiotherapy: a case report

International Nuclear Information System (INIS)

Tamaki, Tomoaki; Nakano, Takashi; Ohno, Tatsuya; Kiyohara, Hiroki; Noda, Shin-ei; Ohkubo, Yu; Ando, Ken; Wakatsuki, Masaru; Kato, Shingo; Kamada, Tadashi

2013-01-01

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

Historical review of radiotherapy

International Nuclear Information System (INIS)

Onai, Yoshio

1993-01-01

The techniques of radiotherapy have been improved by development of particle accelerators, radionuclides and computers. This paper presents a historical review of the physical and technical aspects of radiotherapy in Japan. Changes in the kinds of radiation, such as X-rays, gamma rays, electrons, neutrons and protons used for external radiotherapy, and the equipment involved are described chronologically, and historical changes in the quality of radiotherapy apparatus are outlined. Patient data acquisition equipment, such as X-ray simulator and X-ray CT, beam modifying devices, patient setup devices, and devices to verify treatment fields and patient doses are reviewed historically. Radiation sources for brachytherapy and internal radiotherapy, and remotely controlled afterloading systems are reviewed chronologically. Historical changes in methods to evaluate absorbed doses, dose monitor systems and beam data acquisition systems are outlined. Changes in methods of calculating dose distributions for external X-ray and electron therapy, brachytherapy and internal radiotherapy by unsealded radionuclides are described and calculation techniques for treatment planning system are reviewed. Annual figures in the numbers of radiotherapy equipment, such as telecobalt and telecesium units, linear accelerators, betatrons, microtrons, stereotactic gamma units, conformation radiotherapy units, remotely controlled afterloading systems, and associated equipment such as X-ray simulators and treatment planning systems are provided, as are changes in the number of accelerators by maximum X-ray energy and maximum electron energy, and in the number of licensed hospitals and clinics using small sealed sources. Changes in techniques of external radiotherapy and brachytherapy are described briefly from the point of view of dose distributions. (author)

Risk-adapted targeted intraoperative radiotherapy versus whole-breast radiotherapy for breast cancer

DEFF Research Database (Denmark)

Vaidya, Jayant S; Wenz, Frederik; Bulsara, Max

2014-01-01

The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intraoperative radiotherapy (TARGIT) versus fractionated external beam radiotherapy (EBRT) for breast cancer. We report 5-year results for local recurrence and the first analysis of overall survival....

Calculated fraction of an incident current pulse that will be accelerated by an electron linear accelerator and comparisons with experimental data

International Nuclear Information System (INIS)

Alsmiller, R.G. Jr.; Alsmiller, F.S.; Lewis, T.A.

1986-05-01

In a series of previous papers, calculated results obtained using a one-dimensional ballistic model were presented to aid in the design of a prebuncher for the Oak Ridge Electron Linear Accelerator. As part of this work, a model was developed to provide limits on the fraction of an incident current pulse that would be accelerated by the existing accelerator. In this paper experimental data on this fraction are presented and the validity of the model developed previously is tested by comparing calculated and experimental data. Part of the experimental data is used to fix the physical parameters in the model and then good agreement between the calculated results and the rest of the experimental data is obtained

Towards MRI-guided linear accelerator control: gating on an MRI accelerator.

Science.gov (United States)

Crijns, S P M; Kok, J G M; Lagendijk, J J W; Raaymakers, B W

2011-08-07

To boost the possibilities of image guidance in radiotherapy by providing images with superior soft-tissue contrast during treatment, we pursue diagnostic quality MRI functionality integrated with a linear accelerator. Large respiration-induced semi-periodic target excursions hamper treatment of cancer of the abdominal organs. Methods to compensate in real time for such motion are gating and tracking. These strategies are most effective in cases where anatomic motion can be visualized directly, which supports the use of an integrated MRI accelerator. We establish here an infrastructure needed to realize gated radiation delivery based on MR feedback and demonstrate its potential as a first step towards more advanced image guidance techniques. The position of a phantom subjected to one-dimensional periodic translation is tracked with the MR scanner. Real-time communication with the MR scanner and control of the radiation beam are established. Based on the time-resolved position of the phantom, gated radiation delivery to the phantom is realized. Dose distributions for dynamic delivery conditions with varying gating windows are recorded on gafchromic film. The similarity between dynamically and statically obtained dose profiles gradually increases as the gating window is decreased. With gating windows of 5 mm, we obtain sharp dose profiles. We validate our gating implementation by comparing measured dose profiles to theoretical profiles calculated using the knowledge of the imposed motion pattern. Excellent correspondence is observed. At the same time, we show that real-time on-line reconstruction of the accumulated dose can be performed using time-resolved target position information. This facilitates plan adaptation not only on a fraction-to-fraction scale but also during one fraction, which is especially valuable in highly accelerated treatment strategies. With the currently established framework and upcoming improvements to our prototype-integrated MRI accelerator

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

International Nuclear Information System (INIS)

Arimoto, Takuro; Yamazaki, Akira; Yonesaka, Akio; Matsuzawa, Tooru; Kanai, Naoki

2003-01-01

) 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)

Gemcitabine Chemotherapy and Single-Fraction Stereotactic Body Radiotherapy for Locally Advanced Pancreatic Cancer

International Nuclear Information System (INIS)

Schellenberg, Devin; Goodman, Karyn A.; Lee, Florence; Chang, Stephanie; Kuo, Timothy; Ford, James M.; Fisher, George A.; Quon, Andrew; Desser, Terry S.; Norton, Jeffrey; Greco, Ralph; Yang, George P.; Koong, Albert C.

2008-01-01

Purpose: Fractionated radiotherapy and chemotherapy for locally advanced pancreatic cancer achieves only modest local control. This prospective trial evaluated the efficacy of a single fraction of 25 Gy stereotactic body radiotherapy (SBRT) delivered between Cycle 1 and 2 of gemcitabine chemotherapy. Methods and Materials: A total of 16 patients with locally advanced, nonmetastatic, pancreatic adenocarcinoma received gemcitabine with SBRT delivered 2 weeks after completion of the first cycle. Gemcitabine was resumed 2 weeks after SBRT and was continued until progression or dose-limiting toxicity. The gross tumor volume, with a 2-3-mm margin, was treated in a single 25-Gy fraction by Cyberknife. Patients were evaluated at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT. Results: All 16 patients completed SBRT. A median of four cycles (range one to nine) of chemotherapy was delivered. Three patients (19%) developed local disease progression at 14, 16, and 21 months after SBRT. The median survival was 11.4 months, with 50% of patients alive at 1 year. Patients with normal carbohydrate antigen (CA)19-9 levels either at diagnosis or after Cyberknife SBRT had longer survival (p <0.01). Acute gastrointestinal toxicity was mild, with 2 cases of Grade 2 (13%) and 1 of Grade 3 (6%) toxicity. Late gastrointestinal toxicity was more common, with five ulcers (Grade 2), one duodenal stenosis (Grade 3), and one duodenal perforation (Grade 4). A trend toward increased duodenal volumes radiated was observed in those experiencing late effects (p = 0.13). Conclusion: SBRT with gemcitabine resulted in comparable survival to conventional chemoradiotherapy and good local control. However, the rate of duodenal ulcer development was significant

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

International Nuclear Information System (INIS)

Molla, Meritxell; Escude, Lluis D.; Nouet, Philippe; Popowski, Youri D.Sc.; Hidalgo, Alberto; Rouzaud, Michel; Linero, Dolores; Miralbell, Raymond

2005-01-01

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

A multicentre randomized/controlled trial of a conventional versus modestly accelerated radiotherapy in the laryngeal cancer: influence of a 1 week shortening overall time

International Nuclear Information System (INIS)

Hliniak, A.; Gwiazdowska, B.; Szutkowski, Z.; Kraszewska, E.; Kukolowicz, P.; Jarzabski, A.; Sochacka, B.; Mazurkiewicz, M.; Paprota, K.; Oliskiewicz, W.; Zadrozna, O.; Milecki, P.; Kubiak, M.; Czopkiewicz, L.; Jagas, M.; Gozdz, S.; Wieczorek, A.; Woytowicz, A.; Cisowska, B.; Magdziarz, H.; Nowakowski, S.; Kosniewski, W.; Laskosz, I.; Serafin, A.; Gradon, E.

2002-01-01

Background and purpose: To compare in a phase III study the loco-regional control, disease-free survival and overall survival induced by an accelerated regimen (AF) as compared with conventional regimen (CF) and to analyze the early and late post-radiation morbidity in both arms. Materials and methods: Patients with age≤75, WHO 0-1, suitable for a radical course of radiotherapy T1-T3, N0, M0, stage of glottic and supraglottic laryngeal cancer were randomized to either CF: 66Gy given in 33 fractions over 45 days or AF: 66Gy given in 33 fractions over 38 days (2 fractions every Thursday). A total of 395 patients were included from 05.1995 to 12.1998. Results. Early toxicity: At the end of radiotherapy patients treated with AF complained for more severe reactions than patients treated with CF. In 8 weeks after treatment completion patients treated with AF complained only for more severe pain on swallowing (P=0.027). In 4 months after treatment completion all types of toxicity except for skin teleangiectasia (P=0.001) were similar in the two groups. Loco-regional control: comparison between CF and AF showed no difference in terms of loco-regional control (P=0.37). Conclusions: The improvement in AF in terms of loco-regional control is estimated to be 3-5% in comparison with conventional regimen and is not significant. The intensity of reactions after 4 months was similar in both arms, what suggests the possibility of further shortening of the overall time by few days or enhancing the total dose within the limits of acceptable morbidity

Functional imaging to monitor vascular and metabolic response in canine head and neck tumors during fractionated radiotherapy.

Science.gov (United States)

Rødal, Jan; Rusten, Espen; Søvik, Åste; Skogmo, Hege Kippenes; Malinen, Eirik

2013-10-01

Radiotherapy causes alterations in tumor biology, and non-invasive early assessment of such alterations may become useful for identifying treatment resistant disease. The purpose of the current work is to assess changes in vascular and metabolic features derived from functional imaging of canine head and neck tumors during fractionated radiotherapy. Material and methods. Three dogs with spontaneous head and neck tumors received intensity-modulated radiotherapy (IMRT). Contrast-enhanced cone beam computed tomography (CE-CBCT) at the treatment unit was performed at five treatment fractions. Dynamic (18)FDG-PET (D-PET) was performed prior to the start of radiotherapy, at mid-treatment and at 3-12 weeks after the completion of treatment. Tumor contrast enhancement in the CE-CBCT images was used as a surrogate for tumor vasculature. Vascular and metabolic tumor parameters were further obtained from the D-PET images. Changes in these tumor parameters were assessed, with emphasis on intra-tumoral distributions. Results. For all three patients, metabolic imaging parameters obtained from D-PET decreased from the pre- to the inter-therapy session. Correspondingly, for two of three patients, vascular imaging parameters obtained from both CE-CBCT and D-PET increased. Only one of the tumors showed a clear metabolic response after therapy. No systematic changes in the intra-tumor heterogeneity in the imaging parameters were found. Conclusion. Changes in vascular and metabolic parameters could be detected by the current functional imaging methods. Vascular tumor features from CE-CBCT and D-PET corresponded well. CE-CBCT is a potential method for easy response assessment when the patient is at the treatment unit.

Establishment of a radiotherapy service with a linear accelerator (photons): acceptance tests, dosimetry and quality control

International Nuclear Information System (INIS)

Berdaky, Mafalda Feliciano

2000-01-01

This work presents the operational part of the final process of the establishment of a radiotherapy service with a linear accelerator (6 MeV photon beams), including the acceptance tests, commissioning tests and the implementation of a quality control program through routine mechanical and radiation tests. All acceptance tests were satisfactory, showing results below the allowed limits of the manufacturer, the commissioning tests presented results within those of the international recommendations. The quality control program was performed during 34 months and showed an excellent stability of this accelerator. (author)

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

International Nuclear Information System (INIS)

Budach, W; Hehr, T; Budach, V; Belka, C; Dietz, K

2006-01-01

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

Natural history of intracranial meningioma after radiotherapy

International Nuclear Information System (INIS)

Monzen, Yoshio

1999-01-01

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)

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

Energy Technology Data Exchange (ETDEWEB)

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).

Universal Survival Curve and Single Fraction Equivalent Dose: Useful Tools in Understanding Potency of Ablative Radiotherapy

International Nuclear Information System (INIS)

Park, Clint; Papiez, Lech; Zhang Shichuan; Story, Michael; Timmerman, Robert D.

2008-01-01

Purpose: Overprediction of the potency and toxicity of high-dose ablative radiotherapy such as stereotactic body radiotherapy (SBRT) by the linear quadratic (LQ) model led to many clinicians' hesitating to adopt this efficacious and well-tolerated therapeutic option. The aim of this study was to offer an alternative method of analyzing the effect of SBRT by constructing a universal survival curve (USC) that provides superior approximation of the experimentally measured survival curves in the ablative, high-dose range without losing the strengths of the LQ model around the shoulder. Methods and Materials: The USC was constructed by hybridizing two classic radiobiologic models: the LQ model and the multitarget model. We have assumed that the LQ model gives a good description for conventionally fractionated radiotherapy (CFRT) for the dose to the shoulder. For ablative doses beyond the shoulder, the survival curve is better described as a straight line as predicted by the multitarget model. The USC smoothly interpolates from a parabola predicted by the LQ model to the terminal asymptote of the multitarget model in the high-dose region. From the USC, we derived two equivalence functions, the biologically effective dose and the single fraction equivalent dose for both CFRT and SBRT. Results: The validity of the USC was tested by using previously published parameters of the LQ and multitarget models for non-small-cell lung cancer cell lines. A comparison of the goodness-of-fit of the LQ and USC models was made to a high-dose survival curve of the H460 non-small-cell lung cancer cell line. Conclusion: The USC can be used to compare the dose fractionation schemes of both CFRT and SBRT. The USC provides an empirically and a clinically well-justified rationale for SBRT while preserving the strengths of the LQ model for CFRT

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

International Nuclear Information System (INIS)

Yeung, Anamaria R.; Li, Jonathan G.; Shi Wenyin; Newlin, Heather E.; Chvetsov, Alexei; Liu, Chihray; Palta, Jatinder R.; Olivier, Kenneth

2009-01-01

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.

Fractionated stereotactic radiotherapy as a boost treatment for tumors in the head and neck region

International Nuclear Information System (INIS)

Uno, Takashi; Isobe, Kouichi; Ueno, Naoyuki; Ito, Hisao; Fukuda, Ataru; Sudo, Satoshi; Shirotori, Hiroaki; Kitahara, Isao; Fukushima, Takanori

2010-01-01

The objective of this retrospective study was to report initial results of CyberKnife stereotactic radiotherapy (SRT) boost for tumors in the head and neck area. Between March 2008 and August 2009, 10 patients were treated with SRT boost using CyberKnife system due mainly to unfavorable condition such as tumors in close proximity to serial organs or former radiotherapy fields. Treatment sites were the external auditory canal in two, the nasopharynx in one, the oropharynx in three, the nasal cavity in one, the maxillary sinus in two, and the oligometastatic cervical lymph node in one. All patients underwent preceding conventional radiotherapy of 40 to 60 Gy. Dose and fractionation scheme of the Cyberknife SRT boost was individualized, and prescribed dose ranged from 9 Gy to 16 Gy in 3 to 4 fractions. Among four patients for whom dose to the optic pathway was concerned, the maximum dose was only about 3 Gy for three patients whereas 9.6 Gy in the remaining one patient. The maximum dose for the mandible in one of three patients with oropharyngeal cancer was 19.7 Gy, whereas majority of the bone can be spared by using non-isocentric conformal beams. For a patient with nasopharyngeal cancer, the highest dose in the brain stem was 15 Gy. However, majority of the brain stem received less than 40% of the maximum dose. Although a small volume high dose area within the normal structure could be observed in several patients, results of the present study showed potential benefits of the CyberKnife SRT boost. (author)

Breast cancer radiotherapy: controversies and prospectives

Institute of Scientific and Technical Information of China (English)

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.

Single Fraction Stereotactic Ablative Body Radiotherapy for Oligometastasis: Outcomes from 132 Consecutive Patients.

Science.gov (United States)

Gandhidasan, S; Ball, D; Kron, T; Bressel, M; Shaw, M; Chu, J; Chander, S; Wheeler, G; Plumridge, N; Chesson, B; David, S; Siva, S

2018-03-01

Stereotactic ablative body radiotherapy (SABR) is currently used to treat oligometastases, but the optimum dose/fractionation schedule is unknown. In this study, we evaluated outcomes after single fraction SABR in patients with oligometastatic disease. Single institutional retrospective review of patients treated with single fraction SABR for one to three oligometastases between 2010 and 2015. The primary outcome was freedom from widespread disease defined as distant recurrence not amenable to surgery or SABR; or recurrence with four or more metastases. In total, 186 treatments were delivered in 132 patients. The two most common target sites were lung (51%) and bone (40%). The most frequent single fraction prescription dose was 26 Gy (47%). The most common primary malignancy was genitourinary (n = 46 patients). Freedom from widespread disease was 75% at 1 year (95% confidence interval 67-83%) and 52% at 2 years (95% confidence interval 42-63%). Freedom from local progression at 1 year was 90% (95% confidence interval 85-95%) and at 2 years was 84% (95% confidence interval 77-91%). A compression fracture of the lumbar vertebra was the only grade 3+ treatment-related toxicity. Single fraction SABR is associated with a high rate of freedom from widespread disease, favourable local control and low toxicity comparable with historic multi-fraction SABR reports. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Verification of respiratory-gated radiotherapy with new real-time tumour-tracking radiotherapy system using cine EPID images and a log file.

Science.gov (United States)

Shiinoki, Takehiro; Hanazawa, Hideki; Yuasa, Yuki; Fujimoto, Koya; Uehara, Takuya; Shibuya, Keiko

2017-02-21

A combined system comprising the TrueBeam linear accelerator and a new real-time tumour-tracking radiotherapy system, SyncTraX, was installed at our institution. The objectives of this study are to develop a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine electronic portal image device (EPID) images and a log file and to verify this treatment in clinical cases. Respiratory-gated radiotherapy was performed using TrueBeam and the SyncTraX system. Cine EPID images and a log file were acquired for a phantom and three patients during the course of the treatment. Digitally reconstructed radiographs (DRRs) were created for each treatment beam using a planning CT set. The cine EPID images, log file, and DRRs were analysed using a developed software. For the phantom case, the accuracy of the proposed method was evaluated to verify the respiratory-gated radiotherapy. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker used as an internal surrogate were calculated to evaluate the gating accuracy and set-up uncertainty in the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions. The proposed method achieved high accuracy for the phantom verification. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker were  ⩽3 mm and  ±3 mm in the SI, AP, and LR directions. We proposed a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine EPID images and a log file and showed that this treatment is performed with high accuracy in clinical cases.

Photoneutron intensity variation with field size around radiotherapy linear accelerator 18-MeV X-ray beam

Energy Technology Data Exchange (ETDEWEB)

Al-Ghamdi, H.; Fazal-ur-Rehman [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Jarallah, M.I. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: mibrahim@kfupm.edu.sa; Maalej, N. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2008-08-15

In X-ray radiotherapy accelerators, neutrons are produced mainly by ({gamma},n) reaction when high energy X-rays interact with high Z materials of the linear accelerator head. These materials include the lead (Pb) used as shielding in the collimator, tungsten (W) target used for the production of X-rays and iron (Fe) in the accelerator head. These unwanted neutrons contaminate the therapeutic beam and contribute to the patient dose during the treatment of a cancer patient. Knowing the neutron distribution around the radiotherapy accelerator is therefore desired. CR-39 nuclear track detectors (NTDs) were used to study the variation of fast and thermal neutron relative intensities around an 18 MeV linear accelerator X-ray beam with the field sizes of 0, 10x10, 20x20, 30x30 and 40x40cm{sup 2}. For fast neutron detection, bare NTDs were used. For thermal neutron detection, NTDs were covered with lithium tetra borate (Li{sub 2}B{sub 4}O{sub 7}) converters. The NTDs were placed at different locations in the direction perpendicular to the treatment couch (transversal) and in the direction parallel to the treatment couch (longitudinal) with respect to the isocenter of the accelerator. The fast neutron relative intensity is symmetrical about the beam axis and exhibits an exponential-like drop with distance from the isocenter of the accelerator for all the field sizes. At the primary beam (isocenter), the relative fast neutron intensity is highest for 40x40cm{sup 2} field size and decreases linearly with the decrease in the field size. However, fast neutron intensities do not change significantly with beam size for the measurements outside the primary beam. The fast neutron intensity in the longitudinal direction outside the primary beam decreases linearly with the field size. The thermal neutron intensity, at any location, was found to be almost independent of the field size.

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

Energy Technology Data Exchange (ETDEWEB)

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.}.

High-dose rate fractionated interstitial radiotherapy for oropharyngeal carcinoma

Energy Technology Data Exchange (ETDEWEB)

Nose, Takayuki; Inoue, Toshihiko; Inoue, Takehiro; Teshima, Teruki; Murayama, Shigeyuki [Osaka Univ. (Japan). Faculty of Medicine

1995-03-01

The limitations of treating oropharyngeal cancer patients with definitive external radiotherapy are the complications of salivary glands, taste buds, mandible and temporomandibular joints. To avoid these complications we started interstitial radiotherapy as boost after 46 Gy of external radiotherapy. Ten cases (retromolar trigone; 1, soft palate; 1, base of tongue; 3, lateral wall; 5) were treated with this method and seven cases were controlled locally. With short follow-up period, xerostomia and dysgeusia are less than definitive external radiotherapy as clinical impression and no in-field recurrences have been experienced. With markedly increased tumor dose, the local control rate can be improved. This treatment method will be an alternative to definitive external radiotherapy to gain better QOL and higher control rate. (author).

Palonosetron and prednisolone for the prevention of nausea and emesis during fractionated radiotherapy and 5 cycles of concomitant weekly cisplatin-a phase II study

DEFF Research Database (Denmark)

Ruhlmann, Christina H; Belli, Charlotte; Dahl, Tina

2013-01-01

Recommendations for antiemetic prophylaxis supportive to radiotherapy and concomitant chemotherapy are not evidence-based. The purpose of this study was to evaluate the efficacy of the antiemetic regimen concurrent to fractionated radiotherapy and concomitant weekly cisplatin in two Danish depart...

A phase ii study of concurrent accelerated hyperfractionated radiotherapy and carboplatin/oral etoposide for elderly patients with stage iii non-small-cell lung cancer

International Nuclear Information System (INIS)

Jeremic, Branislav; Shibamoto, Yuta; Milicic, Biljana; Milisavljevic, Slobodan; Nikolic, Nebojsa; Dagovic, Aleksandar; Aleksandrovic, Jasna; Radosavljevic-Asic, Gordana

1999-01-01

Purpose: To investigate feasibility, toxicity, and efficacy of accelerated hyperfractionated radiation therapy and concurrent carboplatin/oral etoposide in elderly (> 70 years) patients with stage III non-small-cell lung cancer. Methods and Materials: Between January 1988 and June 1993, a total of 58 patients entered a phase II study. Carboplatin (400 mg/m 2 ) was given intravenously on days 1 and 29, and etoposide (50 mg/m 2 ) was given orally on days 1-21 and 29-42. Accelerated hyperfractionated radiotherapy was administered starting on day 1, with a total dose of 51 Gy in 34 fractions over 3.5 weeks. Results: In 55 evaluable patients, the complete response rate was 27% and the overall response rate was 65%. For the 55 patients, the median survival time was 10 months, and the 1-, 2-, and 5-year survival rates were 45%, 24%, and 9.1%, respectively. The median time until relapse was 8 months and the 1-, 2-, and 5-year relapse-free survival rates were 45%, 20%, and 9.1%, respectively. The median time to local recurrence was 14 months and the 5-year local control rate was 13%; the median time to distant metastasis was 18 months and the 5-year distant metastasis-free rate was 15%. Hematological, esophageal, and bronchopulmonary acute grade 3 or 4 toxicities were observed in 22%, 7%, and 4% of the patients, respectively. There was no grade 5 toxicity or late grade ≥ 3 toxicity. Conclusion: Concurrent accelerated hyperfractionated radiotherapy and carboplatin/oral etoposide produced relatively low and acceptable toxicity. The survival results appeared to be comparable to those obtained in nonelderly patients with stage III non-small-cell lung cancer treated by full-dose radiation

Four R's of radiotherapy

International Nuclear Information System (INIS)

Withers, H.R.

1975-01-01

Radiotherapy given as multiple doses can be effective in sterilizing cancers, but the processes whereby the neoplasm is eradicated and the normal tissues are preserved are not fully understood. The differential between normal tissue and tumor response is enhanced by dose fractionation, single doses resulting in severe normal tissue injury when the dose is sufficient to control a proportion of treated tumors. Data are reviewed from radiobiological studies on laboratory animals and cultured cells that have thrown some light on four of the phenomena that influence the outcome of fractionated-dose radiotherapy, one or more of which may account for the relative sparing of normal tissues. These are repair of sublethal injury in normal and neoplastic cells, reoxygenation of the tumor, redistribution through the division cycle, and regeneration of surviving normal and malignant cells between dose fractions. These have been called the four R's of fractionated radiotherapy. Other factors are involved in the outcome of multifraction radiotherapy, including maintenance of the architectural integrity of the normal tissues, the volume of tissue irradi []ted, the tumor bed, and the immunocompetence of the host. (90 references) (CH)

Dose rate effect from the relationship between ICRU rectal dose and local control rate in intracavitary radiotherapy for carcinoma of the uterine cervix. Six fraction HDR and three-fraction LDR in three weeks

International Nuclear Information System (INIS)

Jingu, Kenichi; Akita, Yuzou; Ohmagari, Jyunichi

2001-01-01

The dose rate effect, low dose rate radiotherapy (LDR)/high dose rate radiotherapy (HDR), was calculated using the isoeffect ICRU rectal dose by intracavitary radiotherapy (ICRT) for uterine cervix cancer. The subjects analyzed consisted of 78 LDR and 74 HDR patients whose ICRU rectal dose could be calculated and whose local control as stage II/III cases could be evaluated. The point A dose in ICRT was 45-55 Gy/3 fractions/3 weeks for LDR and 30 Gy/6 fractions/3 weeks for HDR. The dose effect relationships associated with local control at each whole pelvis external radiation dose were calculated using the double integration method and Probit analysis, and the 50% and 90% local control ICRU rectal doses were calculated from this relationship. Finally, the dose rate effect LDR/HDR was determined from 50% and 90% local control doses. The dose rate effect calculated from the 50% local control dose was 1.24 and that from the 90% local control dose was 1.14. (author)

Radical radiotherapy for invasive bladder cancer: What dose and fractionation schedule to choose?

International Nuclear Information System (INIS)

Pos, Floris J.; Hart, Guus; Schneider, Christoph; Sminia, Peter

2006-01-01

Purpose: To establish the α/β ratio of bladder cancer from different radiotherapy schedules reported in the literature and provide guidelines for the design of new treatment schemes. Methods and Materials: Ten external beam radiotherapy (EBRT) and five brachytherapy schedules were selected. The biologically effective dose (BED) of each schedule was calculated. Logistic modeling was used to describe the relationship between 3-year local control (LC3y) and BED. Results: The estimated α/β ratio was 13 Gy (95% confidence interval [CI], 2.5-69 Gy) for EBRT and 24 Gy (95% CI, 1.3-460 Gy) for EBRT and brachytherapy combined. There is evidence for an overall dose-response relationship. After an increase in total dose of 10 Gy, the odds of LC3y increase by a factor of 1.44 (95% CI, 1.23-1.70) for EBRT and 1.47 (95% CI, 1.25-1.72) for the data sets of EBRT and brachytherapy combined. Conclusion: With the clinical data currently available, a reliable estimation of the α/β ratio for bladder cancer is not feasible. It seems reasonable to use a conventional α/β ratio of 10-15 Gy. Dose escalation could significantly increase local control. There is no evidence to support short overall treatment times or large fraction sizes in radiotherapy for bladder cancer

Preliminary Results of Fractionated Stereotactic Radiotherapy After Cyst Drainage for Craniopharyngioma in Adults

International Nuclear Information System (INIS)

Kanesaka, Naoto; Mikami, Ryuji; Nakayama, Hidetsugu; Nogi, Sachika; Tajima, Yu; Nakajima, Nobuyuki; Wada, Jun; Miki, Tamotsu; Haraoka, Jou; Okubo, Mitsuru; Sugahara, Shinji; Tokuuye, Koichi

2012-01-01

Purpose: To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for craniopharyngioma. Methods and Materials: Between 1999 and 2005, 16 patients with craniopharyngioma were referred to Tokyo Medical University Hospital. They received FSRT alone after histologic confirmation by needle biopsy and underwent cyst drainage via endoscopy. The median prescription dose fraction was 30 Gy in six fractions. All patients except 1 were followed up until December 2009 or death. Results: The median follow-up period was 52 months (range, 4–117 months). Of the 17 patients, 3 experienced recurrence 4 to 71 months after FSRT. The 3-year local control rate was 82.4%. One patient died of thyroid cancer, and the 3-year survival rate was 94.1%. Eight patients had improved visual fields at a median of 2.5 months after FSRT, but hormonal functions did not improve in any patient. Conclusions: FSRT after cyst drainage seems to be safe and effective for patients with craniopharyngiomas, and it may be a safe alternative to surgery.

Preliminary Results of Fractionated Stereotactic Radiotherapy After Cyst Drainage for Craniopharyngioma in Adults

Energy Technology Data Exchange (ETDEWEB)

Kanesaka, Naoto, E-mail: kaneka@tokyo-med.ac.jp [Department of Radiology, Tokyo Medical University Hospital, Tokyo (Japan); Mikami, Ryuji; Nakayama, Hidetsugu; Nogi, Sachika; Tajima, Yu [Department of Radiology, Tokyo Medical University Hospital, Tokyo (Japan); Nakajima, Nobuyuki; Wada, Jun; Miki, Tamotsu; Haraoka, Jou [Department of Neurosurgery, Tokyo Medical University Hospital, Tokyo (Japan); Okubo, Mitsuru [Department of Radiology, Tokyo Medical University Hachioji Medical Center, Tokyo (Japan); Sugahara, Shinji [Department of Radiology, Tokyo Medical University Ibaraki Medical Center, Tokyo (Japan); Tokuuye, Koichi [Department of Radiology, Tokyo Medical University Hospital, Tokyo (Japan)

2012-03-15

Purpose: To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for craniopharyngioma. Methods and Materials: Between 1999 and 2005, 16 patients with craniopharyngioma were referred to Tokyo Medical University Hospital. They received FSRT alone after histologic confirmation by needle biopsy and underwent cyst drainage via endoscopy. The median prescription dose fraction was 30 Gy in six fractions. All patients except 1 were followed up until December 2009 or death. Results: The median follow-up period was 52 months (range, 4-117 months). Of the 17 patients, 3 experienced recurrence 4 to 71 months after FSRT. The 3-year local control rate was 82.4%. One patient died of thyroid cancer, and the 3-year survival rate was 94.1%. Eight patients had improved visual fields at a median of 2.5 months after FSRT, but hormonal functions did not improve in any patient. Conclusions: FSRT after cyst drainage seems to be safe and effective for patients with craniopharyngiomas, and it may be a safe alternative to surgery.

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

International Nuclear Information System (INIS)

Kron, Tomas; Thomas, Jessica; Fox, Chris; Thompson, Ann; Owen, Rebecca; Herschtal, Alan; Haworth, Annette; Tai, Keen-Hun; Foroudi, Farshad

2010-01-01

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.

Treating all fields in every radiotherapy session? - Questioning the old dogma (or, pelvis radiotherapy: speculations on fractioning)

International Nuclear Information System (INIS)

Faria, S.L.; Ferrigno, R.; Osti, N.

1995-01-01

Twenty years ago Wilson and Hall published paper on the advisability of treating all fields at each radiotherapy session. That was based on the widely accepted method for calculating the biological effect of fractionated treatment in terms of a single quantity: the concept of a nominal standard dose (NSD). It was the beginning of an old dogma in radiation oncology: treating all fields every day. The basis megavoltage units of treatment in Brazil are cobalt and low energy linacs. The country is poor and it is not rare to have patients waiting lines. Due to that situation since five years ago we have been treating pelvic tumors with four fields (box technique) but irradiating only two fields per day. After treating hundreds of patients this way we have found no increased late complications, particularly subcutaneous tissue fibrosis. Previous data showed that TDE factors equal or lower than 90 were not related to any kind of fibrosis. treating pelvic tumors with the box technique but irradiating only two fields per day gives TDF values little greater than doing all four fields per day, but still lower than 90. That may explain why we have found no fibrosis. The impression is that not to treat all fields at each radiotherapy session may be possible with no increased rate of late complications. (author). 10 refs, 3 tabs, 2 figs

Apoptotic potential and cell sensitivity to fractionated radiotherapy

International Nuclear Information System (INIS)

Rupnow, Brent A.; Murtha, Albert D.; Alarcon, Rodolfo M.; Giaccia, Amato J.; Knox, Susan J.

1997-01-01

irradiation resulted in decreased clonogenic survival of Rat-1MycER cells compared to cells treated without c-MycER activation following single doses of radiation from 0 to 10 Gy. The increased radiosensitivity conferred by c-Myc activation was suppressed by Bcl-2 overexpression, suggesting that c-Myc-mediated alterations in clonogenic survival are a result of altered apoptotic potential. While the difference in survival was only 1.22-fold following a single 2 Gy dose between Rat-1MycER cells treated in the presence and absence of c-MycER activation, treatment with 5 fractions of 2 Gy at 12 hour intervals resulted in a 2.99-fold decrease in clonogenic survival. Treatment of cells with 5 fractions of 4 Gy resulted in a 16.4-fold difference in clonogenic survival between cells with activated c-MycER and identical cells with inactive c-MycER, while the difference in survival was only 1.60-fold following a single 4 Gy dose. Bcl-2 overexpression was able to suppress c-Myc-mediated alterations in clonogenic survival following treatment with fractionated radiation. Conclusions: These results argue that increasing the sensitivity of cells to radiation-induced apoptosis can decrease their clonogenic survival in vitro. Furthermore, even small apoptosis-dependent differences in survival following single, small fractions of radiation may result in substantial differences in survival following multiple fractions of radiation. Experiments using Rat-1MycER derived tumor xenografts to test the effects of c-Myc-mediated alterations in apoptotic sensitivity on tumor growth delay following single dose and fractionated radiotherapy, in vivo, are in progress and will be discussed

Intra-fractional uncertainties in image-guided intensity-modulated radiotherapy (IMRT) of prostate cancer

International Nuclear Information System (INIS)

Polat, Buelent; Guenther, Iris; Wilbert, Juergen; Goebel, Joachim; Sweeney, Reinhart A.; Flentje, Michael; Guckenberger, Matthias

2008-01-01

To evaluate intra-fractional uncertainties during intensity-modulated radiotherapy (IMRT) of prostate cancer. During IMRT of 21 consecutive patients, kilovolt (kV) cone-beam computed tomography (CBCT) images were acquired prior to and immediately after treatment: a total of 252 treatment fractions with 504 CBCT studies were basis of this analysis. The prostate position in anterior-posterior (AP) direction was determined using contour matching; patient set-up based on the pelvic bony anatomy was evaluated using automatic image registration. Internal variability of the prostate position was the difference between absolute prostate and patient position errors. Intra-fractional changes of prostate position, patient position, rectal distension in AP direction and bladder volume were analyzed. With a median treatment time of 16 min, intra-fractional drifts of the prostate were > 5 mm in 12% of all fractions and a margin of 6 mm was calculated for compensation of this uncertainty. Mobility of the prostate was independent from the bony anatomy with poor correlation between absolute prostate motion and motion of the bony anatomy (R 2 = 0.24). A systematic increase of bladder filling by 41 ccm on average was observed; however, these changes did not influence the prostate position. Small variations of the prostate position occurred independently from intra-fractional changes of the rectal distension; a weak correlation between large internal prostate motion and changes of the rectal volume was observed (R 2 = 0.55). Clinically significant intra-fractional changes of the prostate position were observed and margins of 6 mm were calculated for this intra-fractional uncertainty. Repeated or continuous verification of the prostate position may allow further margin reduction. (orig.)

Intra-fractional uncertainties in image-guided intensity-modulated radiotherapy (IMRT) of prostate cancer

Energy Technology Data Exchange (ETDEWEB)

Polat, Buelent; Guenther, Iris; Wilbert, Juergen; Goebel, Joachim; Sweeney, Reinhart A.; Flentje, Michael; Guckenberger, Matthias [Wuerzburg Univ. (Germany). Dept. of Radiation Oncology

2008-12-15

To evaluate intra-fractional uncertainties during intensity-modulated radiotherapy (IMRT) of prostate cancer. During IMRT of 21 consecutive patients, kilovolt (kV) cone-beam computed tomography (CBCT) images were acquired prior to and immediately after treatment: a total of 252 treatment fractions with 504 CBCT studies were basis of this analysis. The prostate position in anterior-posterior (AP) direction was determined using contour matching; patient set-up based on the pelvic bony anatomy was evaluated using automatic image registration. Internal variability of the prostate position was the difference between absolute prostate and patient position errors. Intra-fractional changes of prostate position, patient position, rectal distension in AP direction and bladder volume were analyzed. With a median treatment time of 16 min, intra-fractional drifts of the prostate were > 5 mm in 12% of all fractions and a margin of 6 mm was calculated for compensation of this uncertainty. Mobility of the prostate was independent from the bony anatomy with poor correlation between absolute prostate motion and motion of the bony anatomy (R{sup 2} = 0.24). A systematic increase of bladder filling by 41 ccm on average was observed; however, these changes did not influence the prostate position. Small variations of the prostate position occurred independently from intra-fractional changes of the rectal distension; a weak correlation between large internal prostate motion and changes of the rectal volume was observed (R{sup 2} = 0.55). Clinically significant intra-fractional changes of the prostate position were observed and margins of 6 mm were calculated for this intra-fractional uncertainty. Repeated or continuous verification of the prostate position may allow further margin reduction. (orig.)

Combination radiotherapy and chemotherapy for primary lung cancer

International Nuclear Information System (INIS)

Nishikawa, Kiyoshi; Koga, Kenji; Kusuhara, Toshiyuki; Kodama, Takao; Takeuchi, Midori; Watanabe, Katsushi

1984-01-01

Fifty-six patients with carcinoma of the lung treated with radiotherapy alone or combination of chemotherapy were reviewed. Radiation was given with a 10MV photon beam by a linear accelerator. A fraction dose of 2Gy (200 rad) was given routinely 5 times a week. Combined durgs consist of 5FU or FT-207 in monochemotherapy and METT, MFC, or METVFC in combination chemotherapy. 5 year survival rate of all patients was 3.8%. As for the stage classification, 5 year survival rate is 30% in Stage I and II cancer, but there was no 3 year survivor in Stage III cancer and 2 year survivor in Stage IV cancer. As for the cell types, cases of adenocarcinoma had worse prognosis than them of squamous cell carcinoma and small cell carcinoma. The prognosis of patients treated with combination of radiotherapy and chemotherapy was similar to that of patients treated with radiotherapy alone. These results suggest that combined chemotherapy did not influence tumor control. Some discussion on the treatment modality of chemotherapy are made, emphasizing untoward effect of chemotherapy on immunopotency. (author)

Study on the photoneutrons produced in 15 MV medical linear accelerators : Comparison of three dimensional conformal radiotherapy and intensity modulated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Yang, Oh Nam [Gangneung Asan Hospital, Gangneung (Korea, Republic of); Yang, Oh Nam; Lim, Cheong Hwan [Hanseo Univ., Seosan (Korea, Republic of)

2012-12-15

Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photoneutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photon beams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose.

Study on the photoneutrons produced in 15 MV medical linear accelerators : Comparison of three dimensional conformal radiotherapy and intensity modulated radiotherapy

International Nuclear Information System (INIS)

Yang, Oh Nam; Yang, Oh Nam; Lim, Cheong Hwan

2012-01-01

Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photoneutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photon beams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose

Verification of respiratory-gated radiotherapy with new real-time tumour-tracking radiotherapy system using cine EPID images and a log file

Science.gov (United States)

Shiinoki, Takehiro; Hanazawa, Hideki; Yuasa, Yuki; Fujimoto, Koya; Uehara, Takuya; Shibuya, Keiko

2017-02-01

A combined system comprising the TrueBeam linear accelerator and a new real-time tumour-tracking radiotherapy system, SyncTraX, was installed at our institution. The objectives of this study are to develop a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine electronic portal image device (EPID) images and a log file and to verify this treatment in clinical cases. Respiratory-gated radiotherapy was performed using TrueBeam and the SyncTraX system. Cine EPID images and a log file were acquired for a phantom and three patients during the course of the treatment. Digitally reconstructed radiographs (DRRs) were created for each treatment beam using a planning CT set. The cine EPID images, log file, and DRRs were analysed using a developed software. For the phantom case, the accuracy of the proposed method was evaluated to verify the respiratory-gated radiotherapy. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker used as an internal surrogate were calculated to evaluate the gating accuracy and set-up uncertainty in the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions. The proposed method achieved high accuracy for the phantom verification. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker were  ⩽3 mm and  ±3 mm in the SI, AP, and LR directions. We proposed a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine EPID images and a log file and showed that this treatment is performed with high accuracy in clinical cases. This work was partly presented at the 58th Annual meeting of American Association of Physicists in Medicine.

Stereotactic radiotherapy of the prostate: fractionation and utilization in the United States

International Nuclear Information System (INIS)

Weiner, Josph P.; Schwartz, David; Shao, Meng; Osborn, Virginia; Schreiber, David; Choi, Kwang

2017-01-01

To analyze the utilization and fractionation of extreme hypofractionation via stereotactic body radiotherapy (SBRT) in the treatment of prostate cancer. Data was analyzed on men diagnosed with localized prostate cancer between 2004–2012 and treated with definitive-intent radiation therapy, as captured in the National Cancer Database. This database is a hospital-based registry that collects an estimated 70% of all diagnosed malignancies in the United States. There were 299,186 patients identified, of which 4,962 (1.7%) were identified as receiving SBRT as primary treatment. Of those men, 2,082 had low risk disease (42.0%), 2,201 had intermediate risk disease (44.4%), and 679 had high risk disease (13.7%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012. Initially SBRT was more commonly used in academic programs, though as time progressed there was a shift to favor an increased absolute number of men treated in the community setting. Delivery of five separate treatments was the most commonly utilized fractionation pattern, with 4,635 patients (91.3%) receiving this number of treatments. The most common dosing pattern was 725 cGy × 5 fractions (49.6%) followed by 700 cGy × 5 fractions (21.3%). Extreme hypofractionation via SBRT is slowly increasing acceptance. Currently 700-725 cGy × 5 fractions appears to be the most commonly employed scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of this modality is expected to continue to increase

Stereotactic radiotherapy of the prostate: fractionation and utilization in the United States

Energy Technology Data Exchange (ETDEWEB)

Weiner, Josph P.; Schwartz, David; Shao, Meng; Osborn, Virginia; Schreiber, David [Dept. of Radiation Oncology, Veterans Affairs New York Harbor Healthcare System, Brooklyn (United States); Choi, Kwang [Dept. of Radiation Oncology, SUNY Downstate Medical Center, Brooklyn (United States)

2017-06-15

To analyze the utilization and fractionation of extreme hypofractionation via stereotactic body radiotherapy (SBRT) in the treatment of prostate cancer. Data was analyzed on men diagnosed with localized prostate cancer between 2004–2012 and treated with definitive-intent radiation therapy, as captured in the National Cancer Database. This database is a hospital-based registry that collects an estimated 70% of all diagnosed malignancies in the United States. There were 299,186 patients identified, of which 4,962 (1.7%) were identified as receiving SBRT as primary treatment. Of those men, 2,082 had low risk disease (42.0%), 2,201 had intermediate risk disease (44.4%), and 679 had high risk disease (13.7%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012. Initially SBRT was more commonly used in academic programs, though as time progressed there was a shift to favor an increased absolute number of men treated in the community setting. Delivery of five separate treatments was the most commonly utilized fractionation pattern, with 4,635 patients (91.3%) receiving this number of treatments. The most common dosing pattern was 725 cGy × 5 fractions (49.6%) followed by 700 cGy × 5 fractions (21.3%). Extreme hypofractionation via SBRT is slowly increasing acceptance. Currently 700-725 cGy × 5 fractions appears to be the most commonly employed scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of this modality is expected to continue to increase.

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

International Nuclear Information System (INIS)

Henzel, M.; Gross, M.W.; Failing, T.; Strassmann, G.; Engenhart-Cabillic, R.; Hamm, K.; Surber, G.; Kleinert, G.; Sitter, H.

2007-01-01

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.)

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

International Nuclear Information System (INIS)

Dunavoelgyi, Roman; Zehetmayer, Martin; Gleiss, Andreas; Geitzenauer, Wolfgang; Kircher, Karl; Georg, Dietmar; Schmidt-Erfurth, Ursula; Poetter, Richard; Dieckmann, Karin

2013-01-01

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 mm 3 (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

Time factor and repopulation during fractionated radiotherapy. Comparison between two xenografted human squamous cell carcinoma

International Nuclear Information System (INIS)

Hesselmann, S.; Horn, K.; Koenemann, S.; Schuck, A.; Willich, N.; Lindel, K.; Ruebe, C.

2003-01-01

Background: A series of experiments were performed to determine the local tumour control of two human squamous cell carcinoma lines in nude mice. An accelerated-fractionated radiation therapy regime is compared to a conventional-fractionated therapy regime. Material and Methods: KB is a well established human nasopharyngeal squamous cell carcinoma line (ATCC CCL 17). In nude mice KB grows as an low differentiated carcinoma. PEC MB is an undifferentiated squamous cell carcinoma of the maxillary sinus, which was successfully established in nude mice by our group 1993. Both tumors were serially passaged in nude mice. Local irradiation was given without anaesthesia under ambient conditions to air breathing animals using 18 MeV electrons of an linear accelerator (Mevatron 77, Siemens, Munich). Each dose level group consists of six to eight animals. The radiation treatments were given in ten equals fractions using graded dose levels of 2, 3, 4.5, 6 and 8 Gy. The interfraction time interval was 6 hours in the accelerated-fractionated group and 24 hours in the conventional-fractionated group. In the conventional-fractionated group a therapy break was given after 5 fractions for 72 h. The endpoint of the experiments was the dose, which was necessary to control 50% of the tumors (TCD 50 ). The TCD 50 values were calculated after 60 days (Tables 1a and 1b). Results: The experiments show, that with increasing overall treatment time of 8 3/4 days using the same number of fractions under ambient conditions the tumor control dose of the tumor KB increases from 36.3 Gy (95% CI 30.9.. 42.7) to 44.3 Gy (38.3.. 51.2). For the tumor PEC MB the tumor control dose increases from 39.5 Gy (33.4.. 46.7) to 45.5 Gy (37.0.. 56.0). Conclusion: This observed increase of the dose necessary to control the squamous cell carcinoma KB and PEC MB can be caused by repopulation of clonogenic tumors cells, however, other mechanism such as an increasing fraction of hypoxic tumor cells can not be ruled

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

DEFF Research Database (Denmark)

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

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....

Determination of the neutron spectra in the treatment room of a linear accelerator for radiotherapy

International Nuclear Information System (INIS)

Vega C, H.R.; Barquero, R.; Mendez, R.; Iniguez, M.P.

2003-01-01

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)

Quantification of fat fraction in lumbar vertebrae: correlation with age and implications for bone marrow dosimetry in molecular radiotherapy

Science.gov (United States)

Salas-Ramirez, Maikol; Tran-Gia, Johannes; Kesenheimer, Christian; Weng, Andreas Max; Kosmala, Aleksander; Heidemeier, Anke; Köstler, Herbert; Lassmann, Michael

2018-01-01

Absorbed dose to active bone marrow is a predictor of hematological toxicity in molecular radiotherapy. Due to the complex composition of bone marrow tissue, the necessity to improve the personalized dosimetry has led to the application of non-conventional imaging methods in nuclear medicine. The aim of this study is to apply magnetic resonance imaging (MRI) for quantification of the fat fraction in lumbar vertebrae and to analyze its implications for bone marrow dosimetry. First, a highly accelerated two-point Dixon MRI sequence for fat-water separation was validated in a 3T system against the magnetic resonance spectroscopy (MRS) gold standard. The validation was performed in a fat-water phantom composed of 11 vials with different fat fractions between 0% and 100%, and subsequently repeated in the lumbar vertebrae of three healthy volunteers. Finally, a retrospective study was performed by analyzing the fat fraction in five lumbar vertebrae of 44 patients scanned with the two-point Dixon sequence. The two-point Dixon phantom acquisition showed a good agreement (maximum difference  =  2.9%) between the nominal fat fraction and MRS. In the volunteers, a statistical analysis showed a non-significant difference (p  =  0.19) between MRI and MRS. In the patients, gender-specific linear fits for female and male data indicated that the age-dependent marrow conversion (red  →  yellow marrow) is slower in males (0.3% per year) than in females (0.5% per year). Lastly, the fat fraction values showed a considerable variability in patients of similar ages and the same gender. Two-point Dixon MRI enables a non-invasive and spatially resolved quantification of the fat fraction in bone marrow. Our study provides important evidence on the differences in marrow conversion between females and males. In addition, differences were observed in the cellularity values of the International Commission on Radiological Protection (ICRP) reference man (0.7) and the

Advanced Accelerator Applications in Medicine

International Nuclear Information System (INIS)

Rimjiaem, Sakhorn

2015-01-01

besides the original purpose on development of particle acceleratora as research tools in nuclear and high-energy physics, there are large variety of accelerators used in various fileds from fundamental research to industrial usesand applications chemistry, biology and medicine. Pratical accelators used in various field of medical applications since serveral decades. Even through, a large fraction of applications is emphasized on cancer therappy, the number of accelerators used in midicine for other diagnostics and treatments has increased steady over the years. Several types of accelerated particles are used including electron, proton, neutron and ions. Presently, relativistic electron beams and radiation from linear accelerators (linas) are widely used. A combination of positron emission tomography (PRT) and radiotherapy is an example of excellent invention early detection and treat of cancer tumors. The most developments for proton and heavy ion therapy as well as a modern boron neutron capture therapy (BNCT) are also great incoming effective systems. This talk will focus on developments of the accelrator systems as well as overview on biophysical properties and medical aspects of the diacnostics and treatments.

The radiobiology of prostate cancer including new aspects of fractionated radiotherapy

International Nuclear Information System (INIS)

Fowler, Jack F.

2005-01-01

Total radiation dose is not a reliable measure of biological effect when dose-per-fraction or dose-rate is changed. Large differences in biological effectiveness (per gray) are seen between the 2 Gy doses of external beam radiotherapy and the large boost doses given at high dose-rate from afterloading sources. The effects are profoundly different in rapidly or slowly proliferating tissues, that is for most tumors versus late complications. These differences work the opposite way round for prostate tumors versus late complications compared with most other types of tumor. Using the Linear-Quadratic formula it is aimed to explain these differences, especially for treatments of prostate cancer. The unusually slow growth rate of prostate cancers is associated with their high sensitivity to increased fraction size, so a large number of small fractions, such as 35 or 40 'daily' doses of 2 Gy, is not an optimum treatment. Theoretical modeling shows a stronger enhancement of tumor effect than of late complications for larger (and fewer) fractions, in prostate tumors uniquely. Biologically Effective Doses and Normalized Total Doses (in 2 Gy fraction equivalents) are given for prostate tumor, late rectal reactions, and - a new development - acute rectal mucosa. Tables showing the change of fraction-size sensitivity (the alpha/beta ratio) with proliferation rates of tissues lead to the association of slow cell doubling times in prostate tumors with small alpha/beta ratios. Clinical evidence to confirm this biological expectation is reviewed. The alpha/beta ratios of prostate tumors appear to be as low as 1.5 Gy (95% confidence interval 1.3-1.8 Gy), in contrast with the value of about 10 Gy for most other types of tumor. The important point is that alpha/beta ratio=1.5 Gy appears to be significantly less than the alpha/beta ratio=3 Gy for late complications in rectal tissues. Such differences are also emerging from recent clinical results. From this important difference stems

The representitativeness of patient position during the first treatment fractions

DEFF Research Database (Denmark)

Bertelsen, Anders; Nielsen, Morten; Westberg, Jonas

2009-01-01

BACKGROUND: During external radiotherapy daily or even weekly image verification of the patient position might be problematic due to the resulting workload. Therefore it has been customary to perform image verification only at the first treatment fraction. In this study it is investigated whether...... the patient position uncertainty at the initial three treatment fractions is representative for the uncertainty throughout the treatment course. METHODS: Seventy seven patients were treated using Elekta Synergy accelerators. The patients were immobilized during treatment by use of a customized VacFix bag...... and a mask of AquaPlast. Cone beam CT (CBCT) scans were performed at fractions 1, 2, and 3 and at the 10th and 20th treatment fractions. Displacements in patient position, translational and rotational, have been measured by an image registration of the CBCT and the planning CT scan. The displacements data...

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

Directory of Open Access Journals (Sweden)

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

Linear accelerator based stereotactic radiosurgery with micro multi-leaf collimator : technological advancement in precision radiotherapy

International Nuclear Information System (INIS)

Dayananda, S.; Kinhikar, R.A.; Saju, Sherley; Deshpande, D.D.; Jalali, R.; Sarin, R.; Shrivastava, S.K.; Dinshaw, K.A.

2003-01-01

Stereotactic Radiosurgery (SRS) is an advancement on precision radiotherapy, in which stereo tactically guided localized high dose is delivered to the lesion (target) in a single fraction, while sparing the surrounding normal tissue. Radiosurgery has been used to treat variety of benign and malignant lesions as well as functional disorders in brain such as arteriovenous malformation (AVM), acoustic neuroma, solitary primary brain tumor, single metastasis, pituitary adenoma etc

MRI-guided single fraction ablative radiotherapy for early-stage breast cancer : a brachytherapy versus volumetric modulated arc therapy dosimetry study

NARCIS (Netherlands)

Charaghvandi, Ramona K; den Hartogh, Mariska D; van Ommen, Anne-Mar L N; de Vries, Wilfred J H; Scholten, Vincent; Moerland, Rien; Philippens, Mariëlle E P; Schokker, Rogier I; van Vulpen, Marco; van Asselen, B; van den Bongard, Desirée H J G

2015-01-01

BACKGROUND AND PURPOSE: A radiosurgical treatment approach for early-stage breast cancer has the potential to minimize the patient's treatment burden. The dosimetric feasibility for single fraction ablative radiotherapy was evaluated by comparing volumetric modulated arc therapy (VMAT) with an

An improved method to accurately calibrate the gantry angle indicators of the radiotherapy linear accelerators

International Nuclear Information System (INIS)

Chang Liyun; Ho, S.-Y.; Du, Y.-C.; Lin, C.-M.; Chen Tainsong

2007-01-01

The calibration of the gantry angle indicator is an important and basic quality assurance (QA) item for the radiotherapy linear accelerator. In this study, we propose a new and practical method, which uses only the digital level, V-film, and general solid phantoms. By taking the star shot only, we can accurately calculate the true gantry angle according to the geometry of the film setup. The results on our machine showed that the gantry angle was shifted by -0.11 deg. compared with the digital indicator, and the standard deviation was within 0.05 deg. This method can also be used for the simulator. In conclusion, this proposed method could be adopted as an annual QA item for mechanical QA of the accelerator

Sphere of equivalence--a novel target volume concept for intraoperative radiotherapy using low-energy X rays.

Science.gov (United States)

Herskind, Carsten; Griebel, Jürgen; Kraus-Tiefenbacher, Uta; Wenz, Frederik

2008-12-01

Accelerated partial breast radiotherapy with low-energy photons from a miniature X-ray machine is undergoing a randomized clinical trial (Targeted Intra-operative Radiation Therapy [TARGIT]) in a selected subgroup of patients treated with breast-conserving surgery. The steep radial dose gradient implies reduced tumor cell control with increasing depth in the tumor bed. The purpose was to compare the expected risk of local recurrence in this nonuniform radiation field with that after conventional external beam radiotherapy. The relative biologic effectiveness of low-energy photons was modeled using the linear-quadratic formalism including repair of sublethal lesions during protracted irradiation. Doses of 50-kV X-rays (Intrabeam) were converted to equivalent fractionated doses, EQD2, as function of depth in the tumor bed. The probability of local control was estimated using a logistic dose-response relationship fitted to clinical data from fractionated radiotherapy. The model calculations show that, for a cohort of patients, the increase in local control in the high-dose region near the applicator partly compensates the reduction of local control at greater distances. Thus a "sphere of equivalence" exists within which the risk of recurrence is equal to that after external fractionated radiotherapy. The spatial distribution of recurrences inside this sphere will be different from that after conventional radiotherapy. A novel target volume concept is presented here. The incidence of recurrences arising in the tumor bed around the excised tumor will test the validity of this concept and the efficacy of the treatment. Recurrences elsewhere will have implications for the rationale of TARGIT.

Stereotactic radiosurgery vs. fractionated radiotherapy for tumor control in vestibular schwannoma patients

DEFF Research Database (Denmark)

Persson, Oscar; Bartek, Jiri; Shalom, Netanel Ben

2017-01-01

OBJECTIVE: Repeated controlled studies have revealed that stereotactic radiosurgery is better than microsurgery for patients with vestibular schwannoma (VS) ... to patients treated with fractionated stereotactic radiotherapy. RESULTS: No randomized controlled trial (RCT) was identified. None of the identified controlled studies comparing SRS with FSRT were eligible according to the inclusion criteria. Nineteen case series on SRS (n = 17) and FSRT (n = 2) were...... included in the systematic review. Loss of tumor control necessitating a new VS-targeted intervention was found in an average of 5.0% of the patients treated with SRS and in 4.8% treated with FSRT. Mean deterioration ratio for patients with serviceable hearing before treatment was 49% for SRS and 45...

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

International Nuclear Information System (INIS)

Astudillo V, A. J.; Mitsoura, E.; Paredes G, L.; Resendiz G, G.

2014-08-01

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)

Radiotherapy of esophageal cancer in combination with chemotherapy

International Nuclear Information System (INIS)

Jinnouchi, Shoshi; Koga, Kenji; Nishikawa, Kiyoshi; Kihara, Yasushi; Kusuhara, Toshiyuki; Watanabe, Katuji

1983-01-01

The significance of combination of chemotherapy in radiotherapy for esophageal cancer was evaluated in 32 patients. They were irradiated routinely in 5 times a weeks with a fraction dose of 200 rad by 10MV-X-ray linear accelerator. Combined drugs consist of Bleomycin or Pepleomycin in two-third and 5FU or FT-207 in one-third. There was statistically no significance between the results of radiation alone and combined chemotherapy, and the improvement of survival rate could not be obtained by combining chemotherapy. Some discussion on the causes of this unimprovement were made. (author)

Adjuvant radiotherapy for cutaneous melanoma: Comparing hypofractionation to conventional fractionation

International Nuclear Information System (INIS)

Chang, Daniel T.; Amdur, Robert J.; Morris, Christopher G. M.S.; Mendenhall, William M.

2006-01-01

Purpose: To examine locoregional control after adjuvant radiotherapy (RT) for cutaneous melanoma and compare outcomes between conventional fractionation and hypofractionation. Methods and Materials: Between January 1980 and June 2004, 56 patients with high-risk disease were treated with adjuvant RT. Indications for RT included: recurrent disease, cervical lymph node involvement, lymph nodes >3 cm, more than three lymph nodes involved, extracapsular extension, gross residual disease, close or positive margins, or satellitosis. Hypofractionation was used in 41 patients (73%) and conventional fractionation was used in 15 patients (27%). Results: The median age was 61 years (21->90). The median follow-up among living patients was 4.4 years (range, 0.6-14.4 years). The primary site was located in the head and neck in 49 patients (87%) and below the clavicles in 7 patients (13%). There were 7 in-field locoregional failures (12%), 3 out-of-field regional failures (5%), and 24 (43%) distant failures. The 5-year in-field locoregional control (ifLRC) and freedom from distant metastases (FFDM) rates were 87% and 43%, respectively. The 5-year cause-specific (CSS) and overall survival (OS) was 57% and 46%, respectively. The only factor associated with ifLRC was satellitosis (p = 0.0002). Nodal involvement was the only factor associated with FFDM (p = 0.0007), CSS (p = 0.0065), and OS (p = 0.016). Two patients (4%) who experienced severe late complications, osteoradionecrosis of the temporal bone and radiation plexopathy, and both received hypofractionation (5%). Conclusions: Although surgery and adjuvant RT provides excellent locoregional control, distant metastases remain the major cause of mortality. Hypofractionation and conventional fractionation are equally efficacious

Oxygen tension in transplanted mouse osteosarcomas during fractionated high-LET- and low-LET radiotherapy - predictive aspects for choosing beam quality?

International Nuclear Information System (INIS)

Auberger, T.; Thuerriegel, B.; Freude, T.; Weissfloch, L.; Kneschaurek, P.; Molls, M.; Senekowitsch-Schmidtke, R.; Wagner, F.M.

1999-01-01

Murine OTS64 - osteosarcomas were tranplanted in 102 balb-C mice and irradiated by 36 Gy of photons in fractions of 3 Gy five times a week (group P-36/3) or by 12 Gy of reactor fission neutrons in fractions of 2 Gy two times a week (group N-12/2). Irradiations started at a tumor volume of 500 to 600 mm 3 . A third group received no radiotherapy, but all investigations (group CG). Tumor volume and tumor oxygenation were measured once a week under therapy and during three weeks after therapy. For in vivo-evaluation of oxygen status a computerized polarographic needle electrode system (KIMOC pO 2 histograph, Eppendorf) was used. The median pO 2 and the hypoxic fraction (pO 2 values 2 decreased from 20 mm to 8 mm Hg and the hypoxic fraction increased from 7% to 31%. After fractionated photon therapy a growth delay of three weeks was observed. Six weeks after beginning of the irradiation the median tumor volume had been doubled again. After fission neutron therapy growth delay continued until the end of the follow-up period. In both of the irradiated groups a significant decrease of median pO 2 values and an increase of the hypoxic fraction were observed under radiotherapy. Hypoxia was more intensive after neutrons with a decrease of the median pO 2 from 20 mm Hg to 1 mm Hg vs. 10 mm Hg after photon therapy and with an increase of the hypoxic fraction from 7% to 78% vs. 36% respectively. Two weeks after the end of therapy the median pO 2 and the hypoxic fraction of both treated groups reached the levels prior to irradiation indicating a complete reoxygenation. (orig.)

Radiotherapy-induced emesis. An overview

International Nuclear Information System (INIS)

Feyer, P.; Buchali, A.; Hinkelbein, M.; Budach, V.; Zimmermann, J.S.; Titlbach, O.J.

1998-01-01

Background: A significant number of patients receiving radiotherapy experience the distressing side effects of emesis and nausea. These symptoms are some of the most distressing problems for the patients influencing their quality of life. Methods: International study results concerning radiotherapy-induced emesis are demonstrated. A German multicenter questionnaire examining the strategies to prevent or to treat radiotherapy-induced nausea and emesis is presented. An international analysis concerning incidence of emesis and nausea in fractionated radiotherapy patients is discussed. Finally the consensus of the consensus conference on antiemetic therapy from the Perugia International Cancer Conference V is introduced. Results: Untreated emesis can lead to complications like electrolyte disorders, dehydration, metabolic disturbances and nutrition problems with weight loss. Prophylactic antiemetics are often given to patients receiving single high-dose radiotherapy to the abdomen. A survey has revealed that antiemetic prophylaxis is not routinely offered to the patients receiving fractionated radiotherapy. However, there is a need for an effective treatment of emesis for use in this group of patients, too. In 20% of patients nausea and emesis can cause a treatment interruption because of an inadequate control of symptoms. Like in chemotherapy strategies there exist high, moderate, and low emetogenic treatment regimens in radiotherapy as well. The most emetogenic potential has the total body irradiation followed by radiotherapy to the abdomen. Radiotherapy induced emesis can be treated effectively with conventional antiemetics up to 50%. Conclusions: Studies with total body irradiation, fractionated treatment and high-dose single exposures have cleary demonstrated the value of 5-HT3-receptor antagonist antiemetics. There is a response between 60 and 97%. There is no difference in the efficacy of the different 5-HT3-antagonists. High-risk patients should be prophylactic

Misonidazole in fractionated radiotherapy: are many small fractions best

International Nuclear Information System (INIS)

Denekamp, J.; McNally, N.J.; Fowler, J.F.; Joiner, M.C.

1980-01-01

The largest sensitizing effect is always demonstrated with six fractions, each given with 2 g/m 2 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/m 2 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)

Long term results of hypo-fractionated mammary radiotherapy as exclusive treatment of elderly patients suffering from a beast cancer; Resultats a long terme de la radiotherapie mammaire hypofractionnee comme traitement exclusif des patientes agees souffrant d'un cancer du sein

Energy Technology Data Exchange (ETDEWEB)

Chargari, C.; Kirova, Y.; Laki, F.; Savignoni, A.; Dorval, D.; Dendale, R.; Bollet, M.; Fourquet, A.; Campana, F. [Institut Curie, 75 - Paris (France)

2010-10-15

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

Long-Term Outcomes of Vestibular Schwannomas Treated With Fractionated Stereotactic Radiotherapy: An Institutional Experience

International Nuclear Information System (INIS)

Kapoor, Sumit; Batra, Sachin; Carson, Kathryn; Shuck, John; Kharkar, Siddharth; Gandhi, Rahul; Jackson, Juan; Wemmer, Jan; Terezakis, Stephanie; Shokek, Ori; Kleinberg, Lawrence; Rigamonti, Daniele

2011-01-01

Purpose: We assessed clinical outcome and long-term tumor control after fractionated stereotactic radiotherapy (FSRT) for unilateral schwannoma. Methods and Materials: Between 1995 and 2007, 496 patients were treated with fractionated stereotactic radiotherapy at Johns Hopkins Hospital (Baltimore, MD); 385 patients had radiologic follow-up that met the inclusion criteria. The primary endpoint was treatment failure. Secondary endpoints were radiologic progression and clinical outcome. Logistic regression analysis assessed the association of age, race, tumor side, sex, and pretreatment symptoms. Results: In 11 patients (3%) treatment failed, and they required salvage (microsurgical) treatment. Radiologic progression was observed in 116 patients (30.0%), including 35 patients (9%) in whom the treatment volume more than doubled during the follow-up period, although none required surgical resection. Tumors with baseline volumes of less than 1 cm 3 were 18.02 times more likely to progress than those with tumor volumes of 1 cm 3 or greater (odds ratio, 18.02; 95% confidence interval, 4.25-76.32). Treatment-induced neurologic morbidity included 8 patients (1.6%) with new facial weakness, 12 patients (2.8%) with new trigeminal paresthesias, 4 patients (0.9%) with hydrocephalus (1 communicating and 3 obstructive), and 2 patients (0.5%) with possibly radiation-induced neoplasia. Conclusions: Although the rate of treatment failure is low (3%), careful follow-up shows that radiologic progression occurs frequently. When reporting outcome, the 'no salvage surgery needed' and 'no additional treatment needed' criteria for treatment success need to be complemented by the radiologic data.

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

International Nuclear Information System (INIS)

Kong, Weidong; Zhang-Salomons, Jina; Hanna, Timothy P.; Mackillop, William J.

2007-01-01

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

Radiation-Free Weekend Rescued! Continuous Accelerated Irradiation of 7-Days per Week Is Equal to Accelerated Fractionation With Concomitant Boost of 7 Fractions in 5-Days per Week: Report on Phase 3 Clinical Trial in Head-and-Neck Cancer Patients

Energy Technology Data Exchange (ETDEWEB)

Skladowski, Krzysztof, E-mail: skladowski@io.gliwice.pl [Maria Sklodowska-Curie Memorial Cancer Center and the Institute of Oncology, Branch in Gliwice (Poland); Hutnik, Marcin; Wygoda, Andrzej; Golen, Maria; Pilecki, Boleslaw; Przeorek, Wieslawa; Rutkowski, Tomasz; Lukaszczyk-Widel, Beata; Heyda, Alicja; Suwinski, Rafal; Tarnawski, Rafal; Maciejewski, Boguslaw [Maria Sklodowska-Curie Memorial Cancer Center and the Institute of Oncology, Branch in Gliwice (Poland)

2013-03-01

Purpose: To report long-term results of randomized trial comparing 2 accelerated fractionations of definitive radiation therapy assessing the need to irradiate during weekend in patients with head and neck squamous cell carcinoma. Methods and Materials: A total of 345 patients with SCC of the oral cavity, larynx, and oro- or hypo-pharynx, stage T2-4N0-1M0, were randomized to receive continuous accelerated irradiation (CAIR: once per day, 7 days per week) or concomitant accelerated boost (CB: once per day, 3 days per week, and twice per day, 2 days per week). Total dose ranged from 66.6-72 Gy, dose per fraction was 1.8 Gy, number of fractions ranged from 37-40 fractions, and overall treatment time ranged from 37-40 days. Results: No differences for all trial end-points were noted. At 5 and 10 years, the actuarial rates of local-regional control were 63% and 60% for CAIR vs 65% and 60% for CB, and the corresponding overall survival were 40% and 25% vs 44% and 25%, respectively. Confluent mucositis was the main acute toxicity, with an incidence of 89% in CAIR and 86% in CB patients. The 5-year rate of grade 3-4 late radiation morbidity was 6% for both regimens. Conclusions: Results of this trial indicate that the effects of accelerated fractionation can be achieve by delivering twice-per-day irradiation on weekday(s). This trial has also confirmed that an accelerated, 6-weeks schedule is a reasonable option for patients with intermediate-stage head-and-neck squamous cell carcinoma because of the associated high cure rate and minimal severe late toxicity.

Kinetics of EGFR expression during fractionated irradiation varies between different human squamous cell carcinoma lines in nude mice

International Nuclear Information System (INIS)

Eicheler, Wolfgang; Krause, Mechthild; Hessel, Franziska; Zips, Daniel; Baumann, Michael

2005-01-01

Background and purpose: Preclinical and clinical data indicate that high pretherapeutic EGFR expression is associated with poor local tumour control, possibly caused by a high repopulation rate of clonogenic cells during radiotherapy in these tumours. Previous data reported from our laboratory showed a correlation between EGFR expression and acceleration of repopulation in poorly differentiated FaDu human squamous cell carcinoma (SCC) during fractionated irradiation. To test whether this is a general phenomenon, two further SCC were investigated in the present study. Patients and methods: GL and UT-SCC-14, two moderately well differentiated and keratinising hSCC, were grown as xenografts in nude mice. Functional data on the repopulation kinetics during fractionated irradiation for these tumour models have been previously determined. The expression of EGFR during fractionation was analysed by immunohistochemistry. Endpoints were the membrane-staining score and the proportion of EGFR-positive cells (EGFR labelling index). Results: Different kinetics of EGFR expression during fractionated RT were found. In UT-SCC-14, EGFR staining score and labelling index increased significantly during radiotherapy. In GL SCC, the EGFR expression was unchanged. Both tumours are characterized by a small but significant repopulation rate during radiotherapy. Conclusions: The expression of EGFR may change significantly during fractionated irradiation. No clear correlation between EGFR expression and the repopulation kinetics of clonogenic tumour cells during fractionated irradiation was found. The changes in EGFR expression during irradiation warrant further investigation on their prognostic implications and on their importance for therapeutic interventions

A non-invasive method for fractionated steriotactic irradiation of brain tumors with linear accelerator

International Nuclear Information System (INIS)

Hariz, M.I.; Laitinen, L.V.; Henriksson, R.; Saeterborg, N.-E.; Loefroth, P.-O.

1990-01-01

A new technique for fractionated stereotactic irradiation of intracranial lesions is described. The treatment is based on a versatile, non-invasive interface for stereotactic localization of the brain target imaged by computed tomography (CT), angiography or magnetic resonance tomography (MRT), and subsequent repetitive stereotactic irradiation of the target using a linear accelerator. The fractionation of the stereotactic irradiation was intended to meet the requirements of the basic principles of radiobiology. The radiophysical evaluation using phantoms, and the clinical results in a small number of patients, demonstrated a good reproducibilit between repeated positionings of the target in the isocenter of the accelerator, and a high degree of accuracy in the treatment of brain lesions. (authors). 28 refs.; 11 figs.; 1 tab

Twice-a-day fractionated radiotherapy with chemotherapy for advanced laryngeal cancer

International Nuclear Information System (INIS)

Karasawa, Kumiko; Okawa, Tomohiko

1998-01-01

Twenty-five patients with advanced laryngeal cancer were treated with twice-a-day fractionated radiotherapy (TDFR) to a total dose of 65 Gy to 82 Gy combined with chemotherapy of CDDP and 5-FU between 1994 and 1997. Twenty-two cases (88%) became complete response and 9 cases recurred. The relapse-free rate at 2 years was 49.8%. The laryngeal conserving rate at 2 years was 71.0%, the actuarial 2-year survival rate was 89.9%. In induction chemotherapy (12 cases) no severe toxicity has been observed. In TDFR with concurrent chemotherapy (22 cases), grade 3 hematological toxicity was observed in 4 cases and grade 4 mucosal toxicity in 16 cases. Based on this investigation, it is concluded that TDFR with chemotherapy is a promising modality for advanced laryngeal cancer and toxicity is acceptable. (author)

The application of the linear-quadratic model to fractionated radiotherapy when there is incomplete normal tissue recovery between fractions, and possible implications for treatments involving multiple fractions per day

International Nuclear Information System (INIS)

Dale, R.G.

1986-01-01

By extending a previously developed mathematical model based on the linear-quadratic dose-effect relationship, it is possible to examine the consequences of performing fractionated treatments for which there is insufficient time between fractions to allow complete damage repair. Equations are derived which give the relative effectiveness of such treatments in terms of tissue-repair constants (μ values) and α/β ratios, and these are then applied to some examples of treatments involving multiple fractions per day. The interplay of the various mechanisms involved (including repopulation effects) and their possible influence on treatments involving closely spaced fractions are examined. If current indications of the differences in recovery rates between early- and late-reacting normal tissues are representative, then it is shown that such differences may limit the clinical potential of accelerated fractionation regimes, where several fractions per day are given in a relatively short overall time. (author)

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

DEFF Research Database (Denmark)

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 ...... uterus. Uterine shifts based on US imaging contains relative uterus-bone displacement, which is not taken into consideration using CBCT bone match....

Using wavelet multi-resolution nature to accelerate the identification of fractional order system

International Nuclear Information System (INIS)

Li Yuan-Lu; Meng Xiao; Ding Ya-Qing

2017-01-01

Because of the fractional order derivatives, the identification of the fractional order system (FOS) is more complex than that of an integral order system (IOS). In order to avoid high time consumption in the system identification, the least-squares method is used to find other parameters by fixing the fractional derivative order. Hereafter, the optimal parameters of a system will be found by varying the derivative order in an interval. In addition, the operational matrix of the fractional order integration combined with the multi-resolution nature of a wavelet is used to accelerate the FOS identification, which is achieved by discarding wavelet coefficients of high-frequency components of input and output signals. In the end, the identifications of some known fractional order systems and an elastic torsion system are used to verify the proposed method. (paper)

Stereotactic Radiotherapy by 6MV Linear Accelerator

Energy Technology Data Exchange (ETDEWEB)

Oho, Yoon Kyeong; Kim, Mi Hee; Gil, Hak Jun [Catholic University College of Medicine, Seoul (Korea, Republic of)] (and others)

1988-12-15

Eight patients with intracranial tumors or arteriovenous malformation (AVM)s which were less than 3 cm in diameter were treated by a technique of stereotactic radiotherapy during the 4 months period from July 1988 through October 1988 at the Division of Radiation Therapy, Kang-Nam St. Mary's Hospital, Catholic University Medical College. The patients were diagnosed as AVMs in 3 cases, acoustic neurinoma, craniopharyngioma (recurrent), hemangioblastoma, pineocytoma, and pituitary microadenoma in each case. There are several important factors in this procedure, such as localization system, portal, field size, radiation dose, and perioperative supportive care. It is suggested that stereotactic radiotherapy may be performed safely with a radiation dose of 12-30 Gy. So this noninvasive procedure can be used to treat unresectable intracranial tumors or AVMs. Of these, clinical symptoms had been regressed in AVMs in 2 cases at 3 months and 2 months after Stereotactic radiotherapy, one of whom was confirmed slightly regressed on the follow-up angiogram. And also craniopharyngioma and pineocytoma was minimally regressed on 3 month follow-up CT.

Stereotactic Radiotherapy by 6MV Linear Accelerator

International Nuclear Information System (INIS)

Oho, Yoon Kyeong; Kim, Mi Hee; Gil, Hak Jun

1988-01-01

Eight patients with intracranial tumors or arteriovenous malformation (AVM)s which were less than 3 cm in diameter were treated by a technique of stereotactic radiotherapy during the 4 months period from July 1988 through October 1988 at the Division of Radiation Therapy, Kang-Nam St. Mary's Hospital, Catholic University Medical College. The patients were diagnosed as AVMs in 3 cases, acoustic neurinoma, craniopharyngioma (recurrent), hemangioblastoma, pineocytoma, and pituitary microadenoma in each case. There are several important factors in this procedure, such as localization system, portal, field size, radiation dose, and perioperative supportive care. It is suggested that stereotactic radiotherapy may be performed safely with a radiation dose of 12-30 Gy. So this noninvasive procedure can be used to treat unresectable intracranial tumors or AVMs. Of these, clinical symptoms had been regressed in AVMs in 2 cases at 3 months and 2 months after Stereotactic radiotherapy, one of whom was confirmed slightly regressed on the follow-up angiogram. And also craniopharyngioma and pineocytoma was minimally regressed on 3 month follow-up CT

Norm- and hypo-fractionated radiotherapy is capable of activating human dendritic cells.

Science.gov (United States)

Kulzer, Lorenz; Rubner, Yvonne; Deloch, Lisa; Allgäuer, Andrea; Frey, Benjamin; Fietkau, Rainer; Dörrie, Jan; Schaft, Niels; Gaipl, Udo S

2014-10-01

Despite the transient immunosuppressive properties of local radiotherapy (RT), this classical treatment modality of solid tumors is capable of inducing immunostimulatory forms of tumor-cell death. The resulting 'immunotoxicity' in the tumor, but not in healthy tissues, may finally lead to immune-mediated destruction of the tumor. However, little is known about the best irradiation scheme in this setting. This study examines the immunological effects of differently irradiated human colorectal tumor cells on human monocyte-derived dendritic cells (DC). Human SW480 tumor cells were irradiated with a norm-fractionation scheme (5 × 2 Gy), a hypo-fractionated protocol (3 × 5 Gy), and with a high single irradiation dose (radiosurgery; 1 × 15 Gy). Subsequently, human immature DC (iDC) were co-incubated with supernatants (SN) of these differently treated tumor cells. Afterwards, DC were analyzed regarding the expression of maturation markers, the release of cytokines, and the potential to stimulate CD4(+) T-cells. The co-incubation of iDC with SN of tumor cells exposed to norm- or hypo-fractionated RT resulted in a significantly increased secretion of the immune activating cytokines IL-12p70, IL-8, IL-6, and TNFα, compared to iDC co-incubated with SN of tumor cells that received a high single irradiation dose or were not irradiated. In addition, DC-maturation markers CD80, CD83, and CD25 were also exclusively elevated after co-incubation with the SN of fractionated irradiated tumor cells. Furthermore, the SN of tumor cells that were irradiated with norm- or hypo-fractionated RT triggered iDC to stimulate CD4(+) T-cells not only in an allogenic, but also in an antigen-specific manner like mature DC. Collectively, these results demonstrate that norm- and hypo-fractionated RT induces a fast human colorectal tumor-cell death with immunogenic potential that can trigger DC maturation and activation in vitro. Such findings may contribute to the improvement of

Six fractions per week of external beam radiotherapy and high-dose-rate brachytherapy for carcinoma of the uterine cervix: A phase I/II study

International Nuclear Information System (INIS)

Yoon, Sang Min; Huh, Seung Jae; Park, Won; Lee, Jeung Eun; Park, Young Je; Nam, Hee Rim; Lim, Do Hoon; Ahn, Yong Chan

2006-01-01

Purpose: This study evaluated the treatment results of external beam radiotherapy administered in six fractions per week and high-dose-rate (HDR) brachytherapy for the treatment of cervical cancer. Methods and Materials: From July 2000 to July 2003, 43 patients were enrolled in this study. The patients received 45 Gy from a 10-MV photon beam using four-field box or anterior-posterior beams. Parametrial regions and the pelvic side walls were boosted with up to 50.4 Gy using a midline block. The daily fraction dose was 1.8 Gy administered in six-weekly fractions, from Monday to Saturday. HDR brachytherapy was also delivered at doses of 24 Gy to point A in six fractions twice a week. The median follow-up time was 37 months (range, 9-60 months). Results: The median overall treatment time was 51 days for all patients (range, 44-62 days). Thirty-four patients (79.1%) achieved complete remission and 8 (18.6%) achieved partial remission after radiotherapy. Locoregional recurrence occurred in 5 patients (11.6%), and a distant metastasis was encountered in 6 patients (13.9%). The 3-year overall survival, locoregional, and distant metastasis-free survival rates were 74.7%, 87.8%, and 84.7%, respectively. Grade 2 and 3 late rectal complications were encountered in 3 (6.5%) and 1 (2.2%), respectively. There were no Grade 3 late bladder complications. Conclusions: Six fractions per week of external beam radiotherapy and HDR brachytherapy is an effective treatment for patients with a carcinoma of the uterine cervix and can be used as a possible alternative to concomitant chemoradiotherapy in elderly patients or in patients with co-morbidity

Radiotherapy Treatment Planning for Testicular Seminoma

International Nuclear Information System (INIS)

Wilder, Richard B.; Buyyounouski, Mark K.; Efstathiou, Jason A.; Beard, Clair J.

2012-01-01

Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 × 1−2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior–posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior–posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

Radiotherapy Treatment Planning for Testicular Seminoma

Energy Technology Data Exchange (ETDEWEB)

Wilder, Richard B., E-mail: richardbwilder@yahoo.com [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States); Buyyounouski, Mark K. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Efstathiou, Jason A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Beard, Clair J. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center, Boston, MA (United States)

2012-07-15

Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

Proliferation in human tumors and optimum radiotherapy fractionation

International Nuclear Information System (INIS)

Fowler, J.F.; Wisconsin Univ., Madison, WI; Lindstrom, M.J.

1991-01-01

Within the last ten years a number of radiotherapy results have been published which enable the effect of overall time on local control to be examined. In all 12 papers a loss of local control with prolongation is shown, although not all papers show a dependence on total dose. The loss of local control per week ranges from 6 to 25% with a median value of 15%. Development of shorter radiotherapy schedules, by one or two weeks, with allocation of rapidly proliferating tumors to the shorter schedules, is recommended. (author)

Kinetic considerations in the choice of treatment schedules for neuraxis radiotherapy

International Nuclear Information System (INIS)

Wheldon, T.E.

1993-01-01

Neuraxis radiotherapy of radiosensitive tumours such as medulloblastoma is usually carried out using conventionally sized fractions and a shrinking field technique. Plowman and Doughty (Br.J.Radiol., 64 (1991) 603-607) have proposed a partial transmission block (PTB) technique which entails the use of small daily doses over a conventional time period. Radiobiological analysis suggests that, although the PTB technique may be adequate for slowly growing tumours, therapeutic efficacy is likely to be compromised where the tumour doubling time is short. Accelerated hyperfractionation (twice daily fractions) provides a possible alternative to both conventional scheduling and the PTB technique. Direct measurement of the kinetics of tumour cells in CSF, where possible, may provide useful guidance in the choice of regimes. (author)

LINEAR ACCELERATOR FOR USE IN RADIOTHERAPY TREATMENT: STUDY OF PROCESS INNOVATION IN A SUS HOSPITAL OF SERRA GAÚCHA

Directory of Open Access Journals (Sweden)

Andréa Cristina Fermiano Fidelis

2017-03-01

Full Text Available The growth of health structures and their complexity have led Clinical Engineering professionals to carry out studies to develop and implement health technology management programs. In this way, employees of this area, integrated with the health system teams, have contributed to make feasible the use of technologies that offer greater security, functionality and reliability. The radiotherapy area, with the increase in the incidence of new cases of cancer, together with the contingency of the financial resources for health, high cost and complexity of the equipment, motivate studies for its adequate management. This research aimed to identify the technologies applied in the radiotherapy treatment, in particular the linear accelerator, as well as the concept of innovation, innovation in services, innovation in processes and the competitiveness acquired with the aid of innovation. The method used in the research has a qualitative approach, with an exploratory and descriptive objective, with semistructured and open questions and involved bibliographic research on the topic of Innovation and on Linear Accelerator, document analysis, Unit of High Complexity in Oncology visit and interviews at the General Hospital of Caxias do Sul South, presenting, finally, the impacts suffered in the hospital and in the community after the arrival of the Line Accelerator. The results showed that there was process and product innovation, incrementally, in the services offered by the hospital.

Radiotherapy in digestive tumours in elderly patients; Radiotherapie dans les tumeurs digestives chez le patient age

Energy Technology Data Exchange (ETDEWEB)

Guillerme, F.; Clavier, J.B.; Nehme-Schuster, H.; Schumacher, C.; Noel, G. [Centre de lutte contre le cancer Paul-Strauss, Strasbourg (France)

2011-10-15

The authors comment the taking into care of a digestive cancer in the case of elderly patient. These patients are treated by radiotherapy, operative radiotherapy with concomitant chemotherapy, or pre-operative radiotherapy, depending on the age, on the cancer type, with an adaptation of the total dose or with a hypo-fractionation of the treatment. Short communication

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

International Nuclear Information System (INIS)

Stoiber, Eva Maria; Schaible, Benjamin; Herfarth, Klaus; Schulz-Ertner, Daniela; Huber, Peter E; Debus, Jürgen; Oertel, Susanne

2010-01-01

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

Cobalt-60 Machines and Medical Linear Accelerators: Competing Technologies for External Beam Radiotherapy.

Science.gov (United States)

Healy, B J; van der Merwe, D; Christaki, K E; Meghzifene, A

2017-02-01

Medical linear accelerators (linacs) and cobalt-60 machines are both mature technologies for external beam radiotherapy. A comparison is made between these two technologies in terms of infrastructure and maintenance, dosimetry, shielding requirements, staffing, costs, security, patient throughput and clinical use. Infrastructure and maintenance are more demanding for linacs due to the complex electric componentry. In dosimetry, a higher beam energy, modulated dose rate and smaller focal spot size mean that it is easier to create an optimised treatment with a linac for conformal dose coverage of the tumour while sparing healthy organs at risk. In shielding, the requirements for a concrete bunker are similar for cobalt-60 machines and linacs but extra shielding and protection from neutrons are required for linacs. Staffing levels can be higher for linacs and more staff training is required for linacs. Life cycle costs are higher for linacs, especially multi-energy linacs. Security is more complex for cobalt-60 machines because of the high activity radioactive source. Patient throughput can be affected by source decay for cobalt-60 machines but poor maintenance and breakdowns can severely affect patient throughput for linacs. In clinical use, more complex treatment techniques are easier to achieve with linacs, and the availability of electron beams on high-energy linacs can be useful for certain treatments. In summary, there is no simple answer to the question of the choice of either cobalt-60 machines or linacs for radiotherapy in low- and middle-income countries. In fact a radiotherapy department with a combination of technologies, including orthovoltage X-ray units, may be an option. Local needs, conditions and resources will have to be factored into any decision on technology taking into account the characteristics of both forms of teletherapy, with the primary goal being the sustainability of the radiotherapy service over the useful lifetime of the equipment

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

Energy Technology Data Exchange (ETDEWEB)

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

Should carbogen and nicotinamide be given throughout the full course of fractionated radiotherapy regimens?

International Nuclear Information System (INIS)

Rojas, A.M.; Johns, H.; Fiat, P.R.

1993-01-01

Tumor radiosensitization with carbogen and nicotinamide (CON) was compared when both agents were given throughout fractionated radiotherapy with the sensitization observed when administered with only half of the fractions. The effect of overall treatment time on the local control of tumors irradiated in air or with CON was also investigated. Local tumor control of a rodent adenocarcinoma, CaNT, was studied using eight different 20-fraction x-ray regimens. An overall time of either 10 or 20 days was used and CON was given with all, the first half or last half of the treatment. Relative to air, all six sensitizer combinations gave a large and significant increase in sensitization (p much-lt 0.00001). Enhancement ratios were 1.9 and 2.1 when CON was given with all 20 fractions in either 10 or 20 days, respectively. For both overall times, enhancement ratios were reduced by 15-25% when CON was given with only half of the fractions. In air, reducing the treatment time from 20 to 10 days gave a small but significant decrease in the isoeffective doses. When CON was administered with either all or part of a schedule, varying the treatment time had little or no effect on local tumor control. No toxic side-effects were encountered when the sensitizers were administered 10 or 20 times, either once or twice per day. CON is an effective and non-toxic tumor radiosensitizer. In CaNT tumors, a significantly greater effect is seen when CON is given with every fraction of the schedule. The sensitizers reduced or abolished the sparing effect of overall time. 22 refs., 1 fig., 2 tabs

Inclusion of molecular biotherapies with radical radiotherapy: modeling of combined modality treatment schedules

International Nuclear Information System (INIS)

Jones, Bleddyn; Dale, Roger G.

1999-01-01

Purpose: The use of molecular biology based therapies concurrently with radical radiotherapy is likely to offer potential benefits, but there is relatively little use of classical radiobiology in the rationale for such applications. The biological mechanisms that govern the outcomes of radiotherapy need to be completely understood before rational application and optimization of such adjuvant biotherapies with radiotherapy. Methods and Materials: Existing biomathematical models of radiotherapy can be used to explore the possible impact of biotherapies that modify tumor proliferation rates and/or radiosensitivity parameters during radiotherapy. Equations that show how to incorporate biotherapies with the linear-quadratic model of radiation cell kill are presented. Also considered are changes in tumor physiology, such as improved blood flow with enhanced delivery of biotherapy to the tumor cells and accelerated clonogen repopulation during radiotherapy. Monte Carlo random sampling methods are used to simulate these effects in heterogenous tumor populations with variation in radiosensitivities, clonogen numbers, and doubling times, as well as variations in repopulation onset rates and in vascular perfusion rates with time. Results: The time onset and duration of exposure of each type of biotherapy during radical radiotherapy can influence the predicted tumor cure probabilities in subtle ways. In general, the efficacy of biotherapies that radiosensitize will depend upon the number of radiotherapy fractions that are sensitized and the change in blood flow with time during radiotherapy. Biotherapies that control repopulation will depend not only on the duration of exposure but also, where accelerated repopulation occurs, on the time at which biotherapy is initiated during radiotherapy. From the ranges of radiobiological parameters and biotherapy efficacies assumed for exploratory examples, large changes of tumor control probability (TCP) are encountered in individual

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

Energy Technology Data Exchange (ETDEWEB)

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)

Performance of different radiotherapy workload models

International Nuclear Information System (INIS)

Barbera, Lisa; Jackson, Lynda D.; Schulze, Karleen; Groome, Patti A.; Foroudi, Farshad; Delaney, Geoff P.; Mackillop, William J.

2003-01-01

Purpose: The purpose of this study was to evaluate the performance of different radiotherapy workload models using a prospectively collected dataset of patient and treatment information from a single center. Methods and Materials: Information about all individual radiotherapy treatments was collected for 2 weeks from the three linear accelerators (linacs) in our department. This information included diagnosis code, treatment site, treatment unit, treatment time, fields per fraction, technique, beam type, blocks, wedges, junctions, port films, and Eastern Cooperative Oncology Group (ECOG) performance status. We evaluated the accuracy and precision of the original and revised basic treatment equivalent (BTE) model, the simple and complex Addenbrooke models, the equivalent simple treatment visit (ESTV) model, fields per hour, and two local standards of workload measurement. Results: Data were collected for 2 weeks in June 2001. During this time, 151 patients were treated with 857 fractions. The revised BTE model performed better than the other models with a mean vertical bar observed - predicted vertical bar of 2.62 (2.44-2.80). It estimated 88.0% of treatment times within 5 min, which is similar to the previously reported accuracy of the model. Conclusion: The revised BTE model had similar accuracy and precision for data collected in our center as it did for the original dataset and performed the best of the models assessed. This model would have uses for patient scheduling, and describing workloads and case complexity

An antiangiogenic agent (TNP-470) inhibited reoxygenation during fractionated radiotherapy of murine mammary carcinoma

International Nuclear Information System (INIS)

Murata, Rumi; Nishimura, Yasumasa; Hiraoka, Masahiro

1997-01-01

Purpose: TNP-470, a synthetic analogue of fumagillin which is a natural product of Aspergillus fumigatus, has been noted as an angiogenesis inhibitor. Combined effects of TNP-470 with fractionated radiotherapy (RT) were investigated using a mouse tumor. Methods and Materials: Tumors were early generations of mammary carcinoma in C3H/He mice. Treatments were initiated when tumors reached an average diameter of 4-5 mm. Tumor response was evaluated by tumor growth (TG) time assay and 50% tumor control dose (TCD 50 ) assay. Tumors were irradiated locally under hypoxic conditions or in air. Five fractionated radiation doses were given in the TG time assay, whereas a single dose or 10 fractionated doses were given in the TCD 50 assay. TNP-470 (100 mg/kg) was administered subcutaneously twice a week during and/or after RT. Results: In the TG time assay, significant delay of tumor growth was observed by TNP-470 alone (100 mg/kg x 2) compared with control tumors (p 50 assay, no significant difference in TCD 50 s was observed between RT alone and RT combined with TNP-470 in single dose experiments. Hypoxic fraction of tumors calculated from the TCD 50 s was not affected significantly by administrating TNP-470 24 h before RT. On the other hand, in 10-fraction experiments, the TCD 50 (RT with TNP-470, in air) was significantly higher than the TCD 50 (RT alone, in air) (p 50 (RT with TNP-470) and the TCD 50 (RT alone) under hypoxic conditions

Intensified hyperfractionated accelerated radiotherapy limits the additional benefit of simultaneous chemotherapy--results of a multicentric randomized German trial in advanced head-and-neck cancer.

Science.gov (United States)

Staar, S; Rudat, V; Stuetzer, H; Dietz, A; Volling, P; Schroeder, M; Flentje, M; Eckel, H E; Mueller, R P

2001-08-01

, prophylactically given G-CSF was a poor prognostic factor (Cox regression), and resulted in reduced LRC (log-rank test: +/- G-CSF, p = 0.0072). With accelerated radiotherapy, the efficiency of simultaneously given chemotherapy may be not as high as expected when compared to standard fractionated RT. Oropharyngeal carcinomas showed better LRC after HF-ACC-RCT vs. HF-ACC-RT; hypopharyngeal carcinomas did not. Prophylactic G-CSF resulted in an unexpected reduced local control and should be given in radiotherapy regimen only with strong hematologic indication.

Successful treatment of tumor-induced osteomalacia due to an intracranial tumor by fractionated stereotactic radiotherapy.

Science.gov (United States)

Tarasova, Valentina D; Trepp-Carrasco, Alejandro G; Thompson, Robert; Recker, Robert R; Chong, William H; Collins, Michael T; Armas, Laura A G

2013-11-01

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, characterized by tumor secretion of fibroblast growth factor-23 (FGF23) causing hypophosphatemia due to renal phosphate wasting. TIO is usually caused by small, benign, difficult-to-localize, mesenchymal tumors. Although surgery with wide excision of tumor borders is considered the "gold standard" for definitive therapy, it can be associated with considerable morbidity depending on the location. To date, radiation therapy has not been considered as an effective treatment modality in TIO. A 67-year-old female presented with multiple nontraumatic fractures, progressive bone pain, and muscle weakness for 4 years. She was found to have biochemical evidence of urinary phosphate wasting with low serum phosphorus, low-normal serum calcium, normal 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and high serum FGF23 levels. TIO was diagnosed. Selective venous sampling for FGF23 confirmed that a 1.7-cm left frontal mass, radiographically similar to a meningioma, was the causative tumor. She declined surgery due to fear of complications and instead underwent fractionated stereotactic radiotherapy for 6 weeks. In less than 4 years after radiation therapy, she was successfully weaned off phosphorus and calcitriol, starting from 2 g of oral phosphorus daily and 1 μg of calcitriol daily. Her symptoms have resolved, and she has not had any new fractures. Stereotactic radiotherapy was an effective treatment modality for TIO in our patient. Fractionated stereotactic radiation therapy represents an alternative to surgery for patients with TIO who are not surgical candidates or who decline surgery.

Successful Treatment of Tumor-Induced Osteomalacia due to an Intracranial Tumor by Fractionated Stereotactic Radiotherapy

Science.gov (United States)

Trepp-Carrasco, Alejandro G.; Thompson, Robert; Recker, Robert R.; Chong, William H.; Collins, Michael T.

2013-01-01

Context: Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, characterized by tumor secretion of fibroblast growth factor-23 (FGF23) causing hypophosphatemia due to renal phosphate wasting. TIO is usually caused by small, benign, difficult-to-localize, mesenchymal tumors. Although surgery with wide excision of tumor borders is considered the “gold standard” for definitive therapy, it can be associated with considerable morbidity depending on the location. To date, radiation therapy has not been considered as an effective treatment modality in TIO. Objective: A 67-year-old female presented with multiple nontraumatic fractures, progressive bone pain, and muscle weakness for 4 years. She was found to have biochemical evidence of urinary phosphate wasting with low serum phosphorus, low-normal serum calcium, normal 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and high serum FGF23 levels. TIO was diagnosed. Selective venous sampling for FGF23 confirmed that a 1.7-cm left frontal mass, radiographically similar to a meningioma, was the causative tumor. She declined surgery due to fear of complications and instead underwent fractionated stereotactic radiotherapy for 6 weeks. Results: In less than 4 years after radiation therapy, she was successfully weaned off phosphorus and calcitriol, starting from 2 g of oral phosphorus daily and 1 μg of calcitriol daily. Her symptoms have resolved, and she has not had any new fractures. Conclusions: Stereotactic radiotherapy was an effective treatment modality for TIO in our patient. Fractionated stereotactic radiation therapy represents an alternative to surgery for patients with TIO who are not surgical candidates or who decline surgery. PMID:24014621

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

International Nuclear Information System (INIS)

Gaze, Mark N.; Kelly, Charles G.; Kerr, Gillian R.; Cull, Ann; Cowie, Valerie J.; Gregor, Anna; Howard, Grahame C.W.; Rodger, Alan

1997-01-01

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

Geometric accuracy of field alignment in fractionated stereotactic conformal radiotherapy of brain tumors

International Nuclear Information System (INIS)

Kortmann, Rolf D.; Becker, Gerd; Perelmouter, Jury; Buchgeister, Markus; Meisner, Christoph; Bamberg, Michael

1999-01-01

Purpose: To assess the accuracy of field alignment in patients undergoing three-dimensional (3D) conformal radiotherapy of brain tumors, and to evaluate the impact on the definition of planning target volume and control procedures. Methods and Materials: Geometric accuracy was analyzed in 20 patients undergoing fractionated stereotactic conformal radiotherapy for brain tumors. Rigid head fixation was achieved by using cast material. Transfer of stereotactic coordinates was performed by an external positioning device. The accuracy during treatment planning was quantitatively assessed by using repeated computed tomography (CT) examinations in treatment position (reproducibility of isocenter). Linear discrepancies were measured between treatment plan and CT examination. In addition, for each patient, a series of 20 verifications were taken in orthogonal projections. Linear discrepancies were measured between first and all subsequent verifications (accuracy during treatment delivery). Results: For the total group of patients, the distribution of deviations during treatment setup showed mean values between -0.3-1.2 mm, with standard deviations (SD) of 1.3-2.0 mm. During treatment delivery, the distribution of deviations revealed mean values between 0.7-0.8 mm, with SDs of 0.5-0.6 mm, respectively. For all patients, deviations for the transition to the treatment machine were similar to deviations during subsequent treatment delivery, with 95% of all absolute deviations between less than 2.8 and 4.6 mm. Conclusion: Random fluctuations of field displacements during treatment planning and delivery prevail. Therefore, our quantitative data should be considered when prescribing the safety margins of the planning target volume. Repeated CT examination are useful to detect operator errors and large random or systematic deviations before start of treatment. Control procedures during treatment delivery appear to be of limited importance. In addition, our findings should help to

High-dose, hyperfractionated, accelerated radiotherapy using a concurrent boost for the treatment of nonsmall cell lung cancer: unusual toxicity and promising early results

International Nuclear Information System (INIS)

King, Stephen C.; Acker, Jeffrey C.; Kussin, Peter S.; Marks, Lawrence B.; Weeks, Kenneth J.; Leopold, Kenneth A.

1996-01-01

Purpose: The treatment of nonsmall cell lung cancer (NSCLC) with conventional radiotherapy (RT) results in inadequate local tumor control and survival. We report results of a Phase II trial designed to treat patients with a significantly increased total dose administered in a reduced overall treatment time using a hyperfractionated, accelerated treatment schedule with a concurrent boost technique. Methods and Materials: A total of 49 patients with unresectable Stage IIIA/IIIB (38 patients) or medically inoperable Stage I/II (11 patients) NSCLC were prospectively enrolled in this protocol. Radiation therapy was administered twice daily, 5 days/week with > 6 h between each treatment. The primary tumor and adjacent enlarged lymph nodes were treated to a total dose of 73.6 Gy in 46 fractions of 1.6 Gy each. Using a concurrent boost technique, electively irradiated nodal regions were simultaneously treated with a dose of 1.25 Gy/fraction for the first 36 fractions to a total dose of 45 Gy. Results: Median survival for the entire group of 49 patients is 15.3 months. Actuarial survival at 2 years is 46%: 60% for 11 Stage I/II patients, 55% for 21 Stage IIIA patients, and 26% for 17 Stage IIIB patients. The actuarial rate of freedom from local progression at 2 years is 64% for the entire group of 49 patients: 62% for Stage I/II patients, 70% for Stage IIIA patients, and 55% for Stage IIIB patients. Patients who underwent serial bronchoscopic reevaluation (4 Stage I/II, 8 Stage IIIA, and 6 Stage IIIB) have an actuarial rate of local control of 71% at 2 years. The median total treatment time was 32 days. Nine of 49 patients (18%) experienced Grade III acute esophageal toxicity. The 2-year actuarial risk of Grade III or greater late toxicity is 30%. The 2-year actuarial rate of severe-late pulmonary and skin-subcutaneous toxicity is 20% and 15%, respectively. Conclusion: This treatment regimen administers a substantially higher biologically effective dose compared with

Clinical experience with a new stereotactic localisation method for fractionated radiotherapy of extracranial lesions

International Nuclear Information System (INIS)

Engenhart-Cabillic, R.; Pastyr, O.; Wenz, F.; Debus, J.; Schlegel, W.; Bahner, M.L.; Wannenmacher, M.

1996-01-01

Purpose/Objective: Effectiveness of radiotherapy in terms of local control has been shown to be linked with treatment accuracy. Conformal radiation therapy outside the brain maybe limited by relative inaccuracy of positioning and repositioning uncertainty during treatment planning, simulation and radiotherapy. It has been shown that stereotactic localisation methods provide an excellent localisation accuracy for intracranial lesions. The aim of this study was to develop a stereotactic system for the whole body and to test the feasibility in a clinical study. Materials and Method: The system includes a reversible stereotactic patient fixation, localization and positioning system which can be used during CT-imaging for simulation and for treatment. The target volume and adjacent critical structures were outlined for treatment three dimensional planning and the coordinates of the target point were calculated. The overall accuracy of target localization including soft and hardware inaccuracy was measured by a phantom. Three patients with spinal and paraspinal tumors were treated by conventionally fractionated high precision megavoltage radiotherapy with this system. The treatment time was 6 weeks in each patients. The stereotactic coordinates of anatomical landmarks as well as implanted fiducals were measured by CT-imaging, X-ray localization and electronic portal imaging at 20 different paraspinal localisations. Stereotactic CT-imaging was performed for treatment planning and once a week during treatment. Results: Standard deviation of stereotactic coordinats in the phantom was 0.5 mm in the lateral direction (x), 1.0 mm in the cranio-caudal orientation (z) and 1.2 mm in the dorso-ventral orientation. About 60 minutes are required to immobilise the patient properly for the first set-up and the subsequent daily set-up time during therapy was 10 min. In patients a total of 18 CT examination and 56 portal images have been analysed. The mean variation of the stereotactic

A prospective and randomized study of radiotherapy, sequential chemotherapy radiotherapy and concomitant chemo therapy-radiotherapy in unresectable non small cell carcinoma of the lung

Directory of Open Access Journals (Sweden)

Dasgupta Anirban

2006-01-01

Full Text Available Purpose: Treatment of advanced Non small cell lung cancer (NSCLC often produces dismal results. Combination of available treatment modalities has reportedly improved the outcome. A prospectively randomized trial was conducted, comparing combined treatment modalities versus radiotherapy alone, in treatment of unresectable NSCLC. Materials and Methods: A total of 103 patients were randomized to three groups. In group ′A′, 32 patients received radiotherapy alone (6500 cGy/30 fraction. In group ′B′, 35 patients received neoadjuvant chemotherapy (Cisplatin 80 mg/m2 on day 1 and Etoposide 100 mg/m day 1-3 intravenously q3 weeks for 3 cycles, followed by radiotherapy (6000 cGy/30 fractions and 3 more cycles of Chemotherapy, with the same regimen. In group ′C′, 36 patients received radiotherapy (5000 cGy/25 fractions with concurrent chemotherapy (ciplatin 20 mg/m2 + Etoposide 75 mg/m2 intravenously on day 1-5 and day 22-26, followed by 2 more cycles of chemotherapy,q3 weeks with the same regimen. Results: Initial treatment responses were significantly higher in group ′B′ ( P P Conclusion: Addition of chemotherapy with radiation in unresectable NSCLC improves response rates, time to tumour progression and disease free survival, though the same effect is not translated in overall survival.

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

International Nuclear Information System (INIS)

Vega C, H. R.; Hernandez D, V. M.; Letechipia de L, C.; Benites R, J. L.; Salas L, M. A.

2013-10-01

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)

Project of compact accelerator for cancer proton therapy

International Nuclear Information System (INIS)

Picardi, L.; Ronsivalle, C.; Vignati, A.

1995-04-01

The status of the sub-projetc 'Compact Accelerator' in the framework of the Hadrontherapy Project leaded by Prof. Amaldi is described. Emphasis is given to the reasons of the use of protons for radiotherapy applications, to the results of the preliminary design studies of four types of accelerators as possible radiotherapy dedicated 'Compact Accelerator' and to the scenario of the fonts of financial resources

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

International Nuclear Information System (INIS)

Regine, W.F.; Scott, C.; Murray, K.; Curran, W.

2001-01-01

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

Radioprotection of patients in radiotherapy: the gonadal doses resulting from treatments at electron accelerators

International Nuclear Information System (INIS)

Nuesslin, F.; Hassenstein, E.

1977-01-01

Using LiF-dosemeters in a polystyrene phantom dose profiles have been measured. The influence of the following parameters has been studied: accelerator type, primary beam quality (45 and 8 MV X-rays, 45, 18 and 10 MeV electrons), orientation of the phantom, depth in the phantom (0, 1 and 10 cm) and thickness of additional lead sheets put on the phantom surface. Because the dose distribution of the leakage radiation of the accelerator depends mainly on the mechanism of beam production, i.e. on the accelerator type, different anisotropic isodose-patterns have been found. For instance, in case of the betatron the dose maxima are located at opposite sides within the plane of electron orbits. On the other side, there does not exist any favourable direction femal patients should be positioned at to minimize the gonadal dose, because already at 10 cm depth in the phantom the isodose distributions are nearly isotropic. This is caused by the low penetrating capacity of the leakage radiation (2 to 0.6 mm Pb HVL thickness at 45 MV X-rays, depending on the lateral distance from the field). These findings suggest to cover the gonads of male patients undergoing radiotherapy with lead sheets of 1 or 2 mm thickness

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

International Nuclear Information System (INIS)

Arthur, Douglas W.; Schmidt-Ullrich, Rupert K.; Friedman, Richard B.; Wazer, David E.; Kachnic, Lisa A.; Amir, Cyrus; Bear, Harry D.; Hackney, Mary Helen; Smith, Thomas J.; Lawrence, Walter

1999-01-01

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

Atypical fractionation in advanced squamous cell carcinomas of the head and neck

International Nuclear Information System (INIS)

Dobrowsky, W.; Naude, J.; Toth, M.; Millesi, W.; Grasl, M.; Koehler, W.; Kautzky, M.; Pavelka, R.; Dobrowsky, E.

1992-01-01

From May 1990 to May 1991, 23 patients with advanced, inoperable squamous cell cancers, clinically staged as III or IV, were treated by unconventional fractionation radiotherapy. Treatment consisted of a continuous hyper-fractionated accelerated radiotherapy, delivering a total dose of 55.3 Gy within 17 consecutive days. In ten patients radiation therapy was combined with chemotherapy: 20 mg mitomycin C/m 2 , administered by intravenous bolus injection on day 5 of treatment. Apart from a confluent mucositis, treatment tolerance was good. Haematological toxicity from mitomycin C was minor and did not require any specific therapy. The mucosal reaction lasted six weeks (median duration) and was not thought to be increased by additional chemotherapy. In twelve of 23 patients a complete remission of the primary tumour was seen, in patients with lymph node metastases there was a complete response in 14 out of 20 patients. After a median follow-up of 18 months, ten of 23 patients have survived (8/23 without evidence of disease). Eleven patients have died due to local tumour progression and one patient died with distant metastases, being without evidence of local tumour. The advantage of this unconventional fractionation, which takes the described short potential tumour doubling time for heat and neck cancers into account, is discussed. (orig.) [de

Characteristics of Philips SL-20 linear accelerator used for stereotactic radiosurgery/radiotherapy

International Nuclear Information System (INIS)

D'Souza, Harold; Ganesh, T.; Joshi, R.C.; Julka, P.K.; Rath, G.K.; Chander, Subhash; Pant, G.S.

2002-01-01

Commissioning of a stereotactic radiosurgery/stereotactic radiotherapy (SRS/SRT) facility on a modified linear accelerator requires validation of mechanical parameters and establishment of parameters, such as tissue maximum ratio (TMR), relative output factors (OF), and off axis ratios (OAR). The mechanical and beam characteristics of Philips SL-20 linear accelerator modified for SRS/SRT were evaluated and presented. The SRS/SRT procedure carried on Philips SL-20 linear accelerator with Brown-Robert-Wells (BRW) and relocatable Gill-Thomas-Cosman (GTC) head frames along with the Radionics planning system was evaluated. The tertiary collimator consists of the actual treatment cones and their sizes vary from 12.5 mm to 40 mm diameter. The alignment of the auxillary collimator axis with mechanical axes and stability of the isocenter of Philips SL-20 machine was evaluated using Iso-Align device and mechanical isocenter standard (MIS). All the mechanical errors of the linear accelerator were within 1 mm, except the stability of the isocenter while rotating the couch. Alignment of auxiliary collimator axis with the central axis, gantry and couch axes were achieved. The TMR, OF and OAR for 6 MV x-rays from Philips SL-20 linear accelerator for different cone sizes were deduced using a Multidata water phantom with 0.015 cc ion chamber. The difference between 50% width of profiles in two major axes (x and y) were within ± 0.4 mm. The cone dimensions were accurate up to 0.7 mm. The penumbra width for different cones varies from 3.1 mm to 3.5 mm. Dose linearity of the monitoring system was ≤ 1% above 5 MU. The mechanical and beam characteristics including dose linearity of the SL-20 machine are presented. The beam characteristics of this machine are comparable with the other modified linear accelerators for SRS/SRT. The shift of isocenter during rotation of couch can be nullified by fine adjusting laser target localizing frame to the laser position using micrometer screws

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

International Nuclear Information System (INIS)

Hoeller, U.; Biertz, I.; Tribius, S.; Alberti, W.; Flinzberg, S.; Schmelzle, R.

2006-01-01

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.)

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

International Nuclear Information System (INIS)

Edvardsen, Hege; Kristensen, Vessela N.; Grenaker Alnaes, Grethe Irene B.Sc.; Bohn, Mona; Erikstein, Bjorn; Helland, Aslaug; Borresen-Dale, Anne-Lise; Fossa, Sophie Dorothea

2007-01-01

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

High-energy accelerators in medicine

CERN Document Server

Mandrillon, Pierre

1992-05-04

The treatment of tumours with charged particles, ranging from protons to "light ions" ( Carbon, Oxygen, Neon) has many advantages, but up to now has been little used because of the absence of facilities. After the successful pioneering work carried out with accelerators built for physics research, machines dedicated to this new radiotherapy are planned or already in construction. The rationale for this new radiotherapy, the high energy accelerators and the beam delivery systems are presented in these two lectures.

Spinal Cord Doses in Palliative Lung Radiotherapy Schedules

International Nuclear Information System (INIS)

Ffrrcsi, F.H.; Parton, C.

2006-01-01

Aim: We aim to check the safety of the standard palliative radiotherapy techniques by using the Linear quadratic model for a careful estimation of the doses received by the spinal cord, in all standard palliative lung radiotherapy fields and fractionation. Material and Methods: All patients surveyed at this prospective audit were treated with palliative chest radio-therapy for lung cancer over a period from January to June 2005 by different clinical oncology specialists within the department. Radiotherapy field criteria were recorded and compared with the recommended limits of the MRC trial protocols for the dose and fractionation prescribed. Doses delivered to structures off the field central axis were estimated using a standard CT scan of the chest. Dose estimates were made using an SLPLAN planning system. As unexpected spinal cord toxicity has been reported after hypo fractionated chest radiotherapy, a sagittal view was used to calculate the isodoses along the length of the spinal cord that could lie within the RT field. Equivalent dose estimates are made using the Linear Quadratic Equivalent Dose formula (LQED). The relative radiation sensitivity of spinal cord for myelopathy (the a/b dose) cord has been estimated as a/b = 1 Gy. Results: 17 Gy in 2 fraction and 39 Gy in 13 fraction protocols have spinal cord equivalent doses (using the linear-quadratic model) that lie within the conventional safe limits of 50 Gy in 25 fractions for the 100% isodose. However when the dosimetry is modelled for a 6 MV 100 cm isocentric linac in 3 dimensions, and altered separations and air space inhomogeneity are considered, the D-Max doses consistently fall above this limit on our 3 model patients. Conclusion: The 17 Gy in 2 fraction and 39 Gy in 13 fraction protocol would risk spinal cord damage if the radio therapist was unaware of the potential spinal cord doses. Alterative doses are suggested below 15.5 Gy/ 2 fractions (7 days apart) would be most acceptable

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

Energy Technology Data Exchange (ETDEWEB)

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.

Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

International Nuclear Information System (INIS)

Leith, J.L.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Walton, R.E.; Woodruff, K.H.; Howard, J.

1980-01-01

The response of rat spinal cord to irradiation with accelerated heavy ions, in particular carbon and neon ions has been studied. Two different ionization regions in the modified Bragg curve for each ion have been studied for both single and fractionated exposures. We have defined the paralytic response as a function of dose and dose per fraction, and we have determined RBE and repair values. The response of rat spinal cord is both dose and LET dependent, which allows the derivation of RBE and repair values

Single-fraction stereotactic radiotherapy: a dose-response analysis of arteriovenous malformation obliteration

International Nuclear Information System (INIS)

Touboul, Emmanuel; Al Halabi, Assem; Buffat, Laurent; Merienne, Louis; Huart, Judith; Schlienger, Michel; Lefkopoulos, Dimitrios; Mammar, Hamid; Missir, Odile; Meder, Jean-Francois; Laurent, Alex; Housset, Martin

1998-01-01

Purpose: Stereotactic radiotherapy delivered in a high-dose single fraction is an effective technique to obliterate intracranial arteriovenous malformations (AVM). To attempt to analyze the relationships between dose, volume, and obliteration rates, we studied a group of patients treated using single-isocenter treatment plans. Methods and Materials: From May 1986 to December 1989, 100 consecutive patients with angiographically proven AVM had stereotactic radiotherapy delivered as a high-dose single fraction using a single-isocenter technique. Distribution according to Spetzler-Martin grade was as follows: 79 grade 1-3, three grade 4, 0 grade 5, and 18 grade 6. The target volume was spheroid in 74 cases, ellipsoid in 11, and large and irregular in 15. The targeted volume of the nidus was estimated using two-dimensional stereotactic angiographic data and, calculated as an ovoid-shaped lesion, was 1900 ± 230 mm 3 (median 968 mm 3 ; range 62-11, 250 mm 3 ). The mean minimum target dose (D min ) was 19 ± 0.6 Gy (median 20 Gy; range: 3-31.5). The mean volume within the isodose which corresponded to the minimum target dose was 2500 ± 300 mm 3 (median 1200 mm 3 ; range 75-14 900 mm 3 ). The mean maximum dose (D max ) was 34.5 ± 0.5 Gy (median 35 Gy; range 15-45). The mean angiographic follow-up was 42 ± 2.3 months (median 37.5; range 7-117). Results: The absolute obliteration rate was 51%. The 5-year actuarial obliteration rate was 62.5 ± 7%. After univariate analysis, AVM obliteration was influenced by previous surgery (p = 0.0007), D min by steps of 5 Gy (p = 0.005), targeted volume of the nidus (≤968 mm 3 vs. >968 mm 3 ; p = 0.015), and grade according to Spetzler-Martin (grade 1-3 vs. grade 4-6; p = 0.011). After multivariate analysis, the independent factors influencing AVM obliteration were the D min [relative risk (RR) 1.9; 95% confidence interval (CI) 1.4-2.5; p min but does not seem to be influenced by D max and the targeted volume of the nidus

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

International Nuclear Information System (INIS)

Marcu, L.; Van Doorn, T.; Royal Adelaide Hospital,; Olver, I.

2000-01-01

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

The situation of radiotherapy in 2011

International Nuclear Information System (INIS)

2012-06-01

Published within the frame of the French 2009-2013 cancer plan, this report proposes an analysis of the situation of radiotherapy in France. More particularly, it analyses the French offer in terms of radiotherapy treatments and the French position in Europe. A second part analyses equipment (accelerators and other equipment) and techniques aimed at radiotherapy treatment preparation and delivery. The following techniques are addressed: three-dimensional conformational, intensity modulation, intracranial and extracranial stereotactic, image-guided, total body irradiation, hadron-therapy, and peri-operative radiotherapy. The last parts analyse the activity of radiotherapy centres in terms of treated patients, of patient age structure, of sessions and preparations, and of treated pathologies, the medical and paramedical personnel in charge of radiotherapy, and financial and cost aspects

Dependence of the risk of encephalopathy on the radiotherapy volume after combined surgery and radiotherapy of invasive pituitary tumors

International Nuclear Information System (INIS)

Rauhut, F.; Stolke, D.; Stuschke, M.; Sack, H.

2002-01-01

The effectiveness of radiotherapy in reducing tumor recurrence of pituitary adenomas is well documented. On the other hand, the risk of side effects to the surrounding central nervous system normal tissue should not be underestimated. This retrospective study includes 58 patients with subtotally resected pituitary tumors. Photon from a 5,7 MV linear accelerator of a 60 cobalt unit with a source-isocenter distance of 80 cm were used throughout for treatment. The doses per fraction ranged from 45 Gy to 60 Gy. For a direct comparison of the different fractionation schedules, the biological effective total dose with 2 Gy per fraction was calculated for all the different application schemes with doses per fraction longer or smaller than 2 Gy. To do this, a fractionation sensitivity of the normal cerebral tissue by an □/□ value of 2 Gy was assumed. Encephalopathy developed in 17 cases (28 percentage) after follow-up times of more than 5 years. Pathological CT- or MRI-findings were seen in 13 cases. Two factors were important for the genesis of radiogenic encephalopathy: 1. Multivariate analysis revealed that the risk of encephalopathy was associated with the radiation volume. 2. The location of the upper field border line was the strongest prognostic factor associated with the risk of encephalopathy (p < 0.05). (author)

Randomized phase III trial of concurrent chemoradiotherapy vs accelerated hyperfractionation radiotherapy in locally advanced head and neck cancer

International Nuclear Information System (INIS)

Chitapanarux, Imjai; Kamnerdsupaphon, Pimkhuan; Pukanhapan, Nantaka; Tharavichitkul, Ekkasit; Vongtama, Roy

2013-01-01

The aim of this study was to compare the efficacy and safety of concurrent chemoradiotherapy (CCRT) vs accelerated hyperfractionation with concomitant boost (CCB) as a primary treatment for patients with Stage III-IV squamous cell carcinoma of head and neck (SCCHN). A total of 85 non-metastatic advanced SCCHN patients were accrued from January 2003 to December 2007. Of these, 48 and 37 patients received CCRT and CCB, respectively. The patients were randomized to receive either three cycles of carboplatin and 5-fluorouracil plus conventional radiotherapy (CCRT, 66 Gy in 6.5 weeks) or hybrid accelerated radiotherapy (CCB, 70 Gy in 6 weeks). The primary endpoint was determined by locoregional control rate. The secondary endpoints were overall survival and toxicity. With a median follow-up of 43 months (range, 3-102), the 5-year locoregional control rate was 69.6% in the CCRT arm vs 55.0% in the CCB arm (P = 0.184). The 5-year overall survival rate was marginally significantly different (P = 0.05): 76.1% in the CCRT arm vs 63.5% in the CCB arm. Radiotherapy treatment interruptions of more than three days were 60.4% and 40.5% in the CCRT arm and CCB arm, respectively. The median total treatment time was 55.5 days in the CCRT arm and 49 days in the CCB arm. The rate of Grade 3 - 4 acute mucositis was significantly higher in the CCB arm (67.6% vs 41.7%, P = 0.01), but no high grade hematologic toxicities were found in the CCB arm (27.2% vs 0%). CCRT has shown a trend of improving outcome over CCB irradiation in locoregionally advanced head and neck cancer. (author)

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

International Nuclear Information System (INIS)

Combs, Stephanie E; Wick, Wolfgang; Debus, Jürgen; Burkholder, Iris; Edler, Lutz; Rieken, Stefan; Habermehl, Daniel; Jäkel, Oliver; Haberer, Thomas; Haselmann, Renate; Unterberg, Andreas

2010-01-01

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. 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. The Cinderella trial is the first study to evaluate carbon ion

Preliminary results of a phase I/II study of simultaneous modulated accelerated radiotherapy for nondisseminated nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Lee, Sang-wook; Back, Geum Mun; Yi, Byong Yong; Choi, Eun Kyung; Ahn, Seung Do; Shin, Seong Soo; Kim, Jung-hun; Kim, Sang Yoon; Lee, Bong-Jae; Nam, Soon Yuhl; Choi, Seung-Ho; Kim, Seung-Bae; Park, Jin-hong; Lee, Kang Kyoo; Park, Sung Ho; Kim, Jong Hoon

2006-01-01

Purpose: To present preliminary results of intensity-modulated radiotherapy (IMRT) with the simultaneous modulated accelerated radiotherapy (SMART) boost technique in patients with nasopharyngeal carcinoma (NPC). Methods and Materials: Twenty patients who underwent IMRT for nondisseminated NPC at the Asan Medical Center between September 2001 and December 2003 were prospectively evaluated. Intensity-modulated radiotherapy was delivered with the 'step and shoot' SMART technique at prescribed doses of 72 Gy (2.4 Gy/day) to the gross tumor volume, 60 Gy (2 Gy/day) to the clinical target volume and metastatic nodal station, and 46 Gy (2 Gy/day) to the clinically negative neck region. Eighteen patients also received cisplatin once per week. Results: The median follow-up period was 27 months. Nineteen patients completed the treatment without interruption; the remaining patient interrupted treatment for 2 weeks owing to severe pharyngitis and malnutrition. Five patients (25%) had Radiation Therapy Oncology Group Grade 3 mucositis, whereas 9 (45%) had Grade 3 pharyngitis. Seven patients (35%) lost more than 10% of their pretreatment weight, whereas 11 (55%) required intravenous fluids and/or tube feeding. There was no Grade 3 or 4 xerostomia. All patients showed complete response. Two patients had distant metastases and locoregional recurrence, respectively. Conclusion: Intensity-modulated radiotherapy with the SMART boost technique allows parotid sparing, as shown clinically and by dosimetry, and might also be more effective biologically. A larger population of patients and a longer follow-up period are needed to evaluate ultimate tumor control and late toxicity

Patients' preference for radiotherapy fractionation schedule in the palliation of symptomatic unresectable lung cancer

International Nuclear Information System (INIS)

Tang, J. I.; Lu, J. J.; Wong, L. C.

2008-01-01

Full text: The palliative radiotherapeutic management of unresectable non-small-cell lung cancer is controversial, with various fractionation (F x) schedules available. We aimed to determine patient's choice of F x schedule after involvement in a decision-making process using a decision board. A decision board outlining the various advantages and disadvantages apparent in the Medical Research Council study of F x schedules (17 Gy in two fractions vs 39 Gy in 13 fractions) was discussed with patients who met Medical Research Council eligibility criteria. Patients were then asked to indicate their preferred F x schedules, reasons and their level of satisfaction with being involved in the decision making process. Radiation oncologists (R O ) could prescribe radiotherapy schedules irrespective of patients' preferences. Of 92 patients enrolled, 55% chose the longer schedule. English-speaking patients were significantly more likely to choose the longer schedule (P 0.02, 95% confidence interval: 1.2-7.6). Longer F x was chosen because of longer survival (90%) and better local control (12%). Shorter F x was chosen for shorter overall treatment duration (80%), cost (61%) and better symptom control (20%). In all, 56% of patients choosing the shorter schedule had their treatment altered by the treating R O , whereas only 4% of patients choosing longer F x had their treatment altered (P O 's own biases.

Radiotherapy for Vestibular Schwannomas: A Critical Review

International Nuclear Information System (INIS)

Murphy, Erin S.; Suh, John H.

2011-01-01

Vestibular schwannomas are slow-growing tumors of the myelin-forming cells that cover cranial nerve VIII. The treatment options for patients with vestibular schwannoma include active observation, surgical management, and radiotherapy. However, the optimal treatment choice remains controversial. We have reviewed the available data and summarized the radiotherapeutic options, including single-session stereotactic radiosurgery, fractionated conventional radiotherapy, fractionated stereotactic radiotherapy, and proton beam therapy. The comparisons of the various radiotherapy modalities have been based on single-institution experiences, which have shown excellent tumor control rates of 91-100%. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy have successfully improved cranial nerve V and VII preservation to >95%. The mixed data regarding the ideal hearing preservation therapy, inherent biases in patient selection, and differences in outcome analysis have made the comparison across radiotherapeutic modalities difficult. Early experience using proton therapy for vestibular schwannoma treatment demonstrated local control rates of 84-100% but disappointing hearing preservation rates of 33-42%. Efforts to improve radiotherapy delivery will focus on refined dosimetry with the goal of reducing the dose to the critical structures. As future randomized trials are unlikely, we suggest regimented pre- and post-treatment assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.

Preliminary result in patients with primary hepatoma treated by stereotactic radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Kang, Ki Mun; Choi, Ihl Bohng; Kim, In Ah; Choi, Byung Ock; Kang, Young Nam; Han, Sung Tae; Chung, Gyu Won [College of Medicine, Catholic Univ., Seoul (Korea, Republic of); Chai, Gyu Young [College of Medicine, Gyeongsang National Univ., Chinju (Korea, Republic of)

2001-03-01

It is not common to evaluate the response of the fractionated stereotactic radiotherapy (SRT) to primary hepatoma as compared with conventional radiotherapy. The purpose of the study was to take the preliminary result on the clinical trial of primary hepatoma by SRT. From July 1999 to March 2000, thirty three patients were hospitalized in the St. Mary's Hospital, and treated with SRT for extracranial tumors. Among them, 13 patients were diagnosed to primary hepatoma and then applied by frameless SRT using 6 MV linac accelerator. There were 12 male and 1 female patients. They had the age of 44-66 year old (median: 59) and the tumor size of 10-825 cc (median: 185 cc). SRT was given to them 3-5 fractions a week (5 Gy/fraction, 90% isodose line) for 2-3 weeks. Median dose of SRT was 50 Gy and the range was 30-50 Gy. Follow-up period ranged from 3 months to 13 months with median of 8 months. After treating SRT to thirteen patients with primary hepatoma, the response of the tumor was examined by abdominal CT: they are classified by 1 complete regression (7.7%), 7 partial regression (53.8%), 4 minimal regression (30.8%), 1 stable disease (7.7%). The positive responses more than partial remission were 8 patients (61.5%) after the treatment. The level of serum alpha-fetoprotein (AFP) after the treatment as compared with pretreatment had been 92.3% decreased. There was no severe complication except dyspepsia 84.6%, mild nausea 69.2%, transient decreased of hepatic function 15.4% and fever 7.7%. SRT to the patients with primary hepatoma was potentially suggested to become the safe and more effective tool than the conventional radiotherapy even though there were relatively short duration of follow-up and small numbers to be tested.

Hypo-fractionated radiotherapy in the treatment of breast cancer in elderly patients; Radiotherapie hypofractionnee dans le traitement du cancer du sein de la personne agee

Energy Technology Data Exchange (ETDEWEB)

Merikhi, T.; Meziane, A.; Laarit, I.; Bali, M.S.; Bendjazia-Djemaa, A. [CHU de Constantine, Constantine (Algeria)

2011-10-15

The authors report an assessment on the long term of the efficiency and toxicity of a hypo-fractionated radiotherapy scheme: 5 Gy on d1 and d3, 6,5 Gy on d15 and d17, and 5 Gy on d29 and d31. The study is based on 144 patients treated between 1990 and 2007. Results are presented in terms of average follow-up, of survival rate without relapse by 5 and 8 years. This treatment could be a good solution to reduce therapeutic delays and a good response to expectations of elderly patients suffering from breast cancer. Short communication

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

Energy Technology Data Exchange (ETDEWEB)

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

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

International Nuclear Information System (INIS)

Wang, C.C.; Efird, Jimmy; Nakfoor, Bruce; Martins, Patricia

1996-01-01

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

Probability dynamics of a repopulating tumor in case of fractionated external radiotherapy.

Science.gov (United States)

Stavreva, Nadia; Stavrev, Pavel; Fallone, B Gino

2009-12-01

In this work two analytical methods are developed for computing the probability distribution of the number of surviving cells of a repopulating tumor during a fractionated external radio-treatment. Both methods are developed for the case of pure birth processes. They both allow the description of the tumor dynamics in case of cell radiosensitivity changing in time and for treatment schedules with variable dose per fraction and variable time intervals between fractions. The first method is based on a direct solution of the set of differential equations describing the tumor dynamics. The second method is based on the works of Hanin et al. [Hanin LG, Zaider M, Yakovlev AY. Distribution of the number of clonogens surviving fractionated radiotherapy: a long-standing problem revisited. Int J Radiat Biol 2001;77:205-13; Hanin LG. Iterated birth and death process as a model of radiation cell survival. Math Biosci 2001;169:89-107; Hanin LG. A stochastic model of tumor response to fractionated radiation: limit theorems and rate of convergence. Math Biosci 2004;191:1-17], where probability generating functions are used. In addition a Monte Carlo algorithm for simulating the probability distributions is developed for the same treatment conditions as for the analytical methods. The probability distributions predicted by the three methods are compared graphically for a certain set of values of the model parameters and an excellent agreement is found to exist between all three results, thus proving the correct implementation of the methods. However, numerical difficulties have been encountered with both analytical methods depending on the values of the model parameters. Therefore, the Poisson approximation is also studied and it is compared to the exact methods for several different combinations of the model parameter values. It is concluded that the Poisson approximation works sufficiently well only for slowly repopulating tumors and a low cell survival probability and that it

The future of breast cancer radiotherapy: From one size fits all to taylor-made treatment; L'avenir de la radiotherapie du cancer du sein: de la taille unique au sur-mesure

Energy Technology Data Exchange (ETDEWEB)

Hennequin, C. [Service de cancerologie-radiotherapie, hopital Saint-Louis, 1, avenue Claude-Vellefaux, 75475 Paris (France); Azria, D. [Departement de cancerologie radiotherapie, CRLC Val-d' Aurelle-Paul-Lamarque, rue Croix-Verte, 34298 Montpellier cedex 5 (France); Universite de Montpellier I, 5, boulevard Henri-IV, CS 19044, 34967 Montpellier cedex 2 (France); Inserm U896, institut de recherche en cancerologie de Montpellier, CRLC Val-d' Aurelle-Paul-Lamarque, rue Croix-Verte, 34298 Montpellier cedex 5 (France)

2011-10-15

Various subgroups of breast tumours have been identified during the last 10 years according to the risk of local relapse. Prognostic factors for local relapse are age, surgical margins, tumour size, Her2 expression and hormonal receptors status. For tumours with a high risk of local relapse, an increased in boost dose or the addition of new drugs (trastuzumab, anti-angiogenics, PARP inhibitors) could be considered. For low risk tumours, hypo-fractionated, accelerated partial breast and intraoperative radiotherapy are being evaluated. The classical schedule (45-50 Gy to the whole gland followed by a boost dose of 16 Gy) is no longer the universal rule. Treatment individualization, according to clinical and biological characteristics of the tumour and - possibly - to the radiobiological profile of the patient, is likely to be the future of breast cancer radiotherapy. (authors)

SU-E-T-427: Cell Surviving Fractions Derived From Tumor-Volume Variation During Radiotherapy for Non-Small Cell Lung Cancer: Comparison with Predictive Assays

Energy Technology Data Exchange (ETDEWEB)

Chvetsov, A; Schwartz, J; Mayr, N [University of Washington, Seattle, WA (United States); Yartsev, S [London Health Sciences Centre, London, Ontario (Canada)

2014-06-01

Purpose: To show that a distribution of cell surviving fractions S{sub 2} in a heterogeneous group of patients can be derived from tumor-volume variation curves during radiotherapy for non-small cell lung cancer. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage (MV) computed tomography (CT). Statistical distributions of cell surviving fractions S{sup 2} and cell clearance half-lives of lethally damaged cells T1/2 have been reconstructed in each patient group by using a version of the two-level cell population tumor response model and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Non-small cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractions S{sub 2} for non-small cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S{sup 2} reconstructed from tumor volume variation agree with the PDF measured in vitro. Comparison of the reconstructed cell surviving fractions with patient survival data shows that the patient survival time decreases as the cell surviving fraction increases. Conclusion: The data obtained in this work suggests that the cell surviving fractions S{sub 2} can be reconstructed from the tumor volume

SU-E-T-427: Cell Surviving Fractions Derived From Tumor-Volume Variation During Radiotherapy for Non-Small Cell Lung Cancer: Comparison with Predictive Assays

International Nuclear Information System (INIS)

Chvetsov, A; Schwartz, J; Mayr, N; Yartsev, S

2014-01-01

Purpose: To show that a distribution of cell surviving fractions S 2 in a heterogeneous group of patients can be derived from tumor-volume variation curves during radiotherapy for non-small cell lung cancer. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage (MV) computed tomography (CT). Statistical distributions of cell surviving fractions S 2 and cell clearance half-lives of lethally damaged cells T1/2 have been reconstructed in each patient group by using a version of the two-level cell population tumor response model and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Non-small cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractions S 2 for non-small cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S 2 reconstructed from tumor volume variation agree with the PDF measured in vitro. Comparison of the reconstructed cell surviving fractions with patient survival data shows that the patient survival time decreases as the cell surviving fraction increases. Conclusion: The data obtained in this work suggests that the cell surviving fractions S 2 can be reconstructed from the tumor volume variation curves measured

Radiotherapy for bone metastases - Practice in Norway 1997 - 2007. A national registry-based study

Energy Technology Data Exchange (ETDEWEB)

Sande Laugsand, Tonje [European Palliative Care Research Centre (PRC), Faculty of Medicine, Norwegian Univ. of Technology and Science (NTNU), Trondheim (Norway)], e-mail: tonje.laugsand@ntnu.no; Kaasa, Stein; Lund, Jo-Aasmund [European Palliative Care Research Centre (PRC), Faculty of Medicine, Norwegian Univ. of Technology and Science (NTNU), Trondheim (Norway); Cancer Clinic, St. Olavs Hospital, Univ. Hospital of Trondheim, Trondheim (Norway); Romundstad, Paal [Dept. of Public Health, Faculty of Medicine, Norwegian Univ. of Technology and Science (NTNU), Trondheim (Norway); Johannesen, Tom Boerge [Cancer Registry of Norway, Oslo (Norway)

2013-08-15

Numerous randomised clinical trials have shown that the efficacy of single fraction radiotherapy for metastatic bone pain corresponds to that of multiple fractions of radiotherapy for the majority of patients. It is not clear to which extent single fraction radiotherapy has been implemented into clinical practice. Material and methods: A Norwegian national registry based study was conducted, including all radiotherapy schedules of 8 Gy x 1 and 3 Gy x 10 delivered to bone metastases in 1997 - 2007. Binomial regression analyses were used to study whether treatment centre, primary diagnosis, anatomical region irradiated, age, sex, and travel distance, were associated with the choice of fractionation. Results: A total of 14 380 radiotherapy episodes were identified. During the period 31% of the treatments were delivered as 8 Gy x 1. The proportion of single fraction treatments increased from 16% in 1997 to 41% in 2007. There were substantial differences in the proportion of single fraction treatments between the treatment centres (range 25 - 54%). These differences persisted after adjustment for sex, age, primary diagnosis, anatomical region, and travel distance. Conclusions: The study demonstrates an under utilisation of single fraction treatment for bone metastases in Norway during the study period.

Monitoring of tumor microcirculation during fractionated radiotherapy in patients with rectal carcinomas: a clinical study using contrast enhanced MR imaging

International Nuclear Information System (INIS)

Vries, A. de; Judmaier, W.; Griebel, J.; Kremser, Ch.; Gneiting, T.; Peer, S.; Aichner, F.; Lukas, P.

1996-01-01

Purpose/Objective: Combined radio chemotherapy is a frequently used treatment scheme for malignant neoplasms. The purpose of using chemotherapeutics such as 5-FU during radiotherapy is to enhance the effectiveness of radiation. The effectiveness of this approach depends on the accumulation of the drugs within the tumor, which is governed by micro circulatory parameters. However, to date scheduling of chemotherapy application is based on empirical data. There is no clinical study available monitoring tumor microcirculation during fractionated radiotherapy. Contrast enhanced MR imaging in tumors provides not only a better understanding of tumor micro vascularity but is also a method to characterize the substance accumulation within the tumor matrix during radiotherapy. This could help to optimize the scheduling of chemotherapy application. Materials and Methods: Patients with clinical and histological proven rectal carcinoma underwent a preoperative combined radio chemotherapy up to a total dose of 39,4Gy, hyperfractionated with b.i.d., single dose 1,1Gy. The fields in box-technique included the rectal canal and adjacent lymph nodes. 5-FU (300mg/m 2 per treatment day) was given continuously parallel to irradiation. To evaluate the Gd-DTPA (Magnevist, Schering, Germany) concentration time curve after i.v. constant rate infusion (0,05 mmol/kg Gd-DTPA) we used an ultrafast T1-mapping sequence on a 1,5-T whole body imager (Magneton Vision, Siemens, Germany). The transaxial slice (thickness 5 mm) was chosen so that both tumor and arterial vessels could be clearly identified. Before, during and after the infusion 53 T1 maps were obtained within 40 min in intervals of 14s (35 scans) and 120s (15 scans). Assuming a linear relation between relaxation rate, R1=1/T1, and Gd-DTPA concentration, concentration time curves were evaluated for arterial blood and tumor. The patients underwent MR imaging before and in constant intervals during fractionated radiotherapy. As a first

Intensified hyperfractionated accelerated radiotherapy limits the additional benefit of simultaneous chemotherapy--results of a multicentric randomized German trial in advanced head-and-neck cancer

International Nuclear Information System (INIS)

Staar, Susanne; Rudat, Volker; Stuetzer, Hartmut; Dietz, Andreas; Volling, Peter; Schroeder, Michael; Flentje, Michael; Eckel, Hans Edmund; Mueller, Rolf-Peter

2001-01-01

tumor locations, prophylactically given G-CSF was a poor prognostic factor (Cox regression), and resulted in reduced LRC (log-rank test: ± G-CSF, p=0.0072). Conclusion: With accelerated radiotherapy, the efficiency of simultaneously given chemotherapy may be not as high as expected when compared to standard fractionated RT. Oropharyngeal carcinomas showed better LRC after HF-ACC-RCT vs. HF-ACC-RT; hypopharyngeal carcinomas did not. Prophylactic G-CSF resulted in an unexpected reduced local control and should be given in radiotherapy regimen only with strong hematologic indication

Fractionated vs. single-fraction stereotactic radiotherapy in patients with vestibular schwannoma. Hearing preservation and patients' self-reported outcome based on an established questionnaire

International Nuclear Information System (INIS)

Kessel, Kerstin A.; Fischer, Hanna; Vogel, Marco M.E.; Combs, Stephanie E.; Oechsner, Markus; Bier, Henning; Meyer, Bernhard

2017-01-01

Stereotactic radiotherapy (RT) has been established as a valid treatment alternative in patients with vestibular schwannoma (VS). There is ongoing controversy regarding the optimal fractionation. Hearing preservation may be the primary goal for patients with VS, followed by maintenance of quality of life (QoL). From 2002 to 2015, 184 patients with VS were treated with radiosurgery (RS) or fractionated stereotactic radiotherapy (FSRT). A survey on current symptoms and QoL was conducted between February and June 2016. Median follow-up after RT was 7.5 years (range 0-14.4 years). Mean overall survival (OS) after RT was 31.1 years, with 94 and 87% survival at 5 and 10 years, respectively. Mean progression-free survival (PFS) was 13.3 years, with 5- and 10-year PFS of 92%. Hearing could be preserved in RS patients for a median of 36.3 months (range 2.3-13.7 years). Hearing worsened in 17 (30%) cases. Median hearing preservation for FSRT was 48.7 months (range 0.0-13.8 years); 29 (23%) showed hearing deterioration. The difference in hearing preservation was not significant between RS and FSRT (p = 0.3). A total of 123/162 patients participated in the patient survey (return rate 76%). The results correlate well with the information documented in the patient files for tinnitus and facial and trigeminal nerve toxicity. Significant differences appeared regarding hearing impairment, gait uncertainty, and imbalance. These data confirm that RS and FSRT are comparable in terms of local control for VS. RS should be reserved for smaller lesions, while FSRT can be offered independently of tumor size. Patient self-reported outcome during follow-up is of high value. The established questionnaire could be validated in the independent cohort. (orig.) [de

Hypo fractionated conformal irradiation of patients with malignant glioma

International Nuclear Information System (INIS)

Aboziada, M.A.; Abo-Kresha, A.E.

2012-01-01

Purpose: The aim of the study is to evaluate the effect of a conformal irradiation in short fractionation scheme of 49.5 Gy in 15 fractions in an overall time of 3 weeks, in terms of overall survival (OAS) and progression free survival (PFS) rates in brain glioma patients. Patients and methods: A prospective study was conducted on 54 brain glioma patients and was carried out in the Radiation Oncology Department, South Egypt Cancer Institute, Assiut University during the period from April 2006 till June 2009. Patients were treated by hypo fractionated conformal irradiation (49.5 Gy/15 fractions/3 weeks). Results: The median follow up was 23 months (range: 9-39 months). Two-year OAS and PFS rates were 68% and 60%, respectively. In univariate analysis, age > 50 years, poor performance status [Karnofasky score of >40- 50 years and glioblastoma pathology were the only independent prognostic factors that were associated with poor OAS (p = 0.003 and p = 0.004, respectively), and PFS (p = 0.027 and p = 0.011, respectively). Conclusion: Hypo fractionated conformal radiotherapy was as effective as the conventional radiotherapy, with time sparing for patients, and for radiation oncology centers. Hypo fractionated radiotherapy may be considered the radiotherapy regimen of choice in clinical practice for patients with gliomas

Short-term irradiation of the glioblastoma with high-dosed fractions

International Nuclear Information System (INIS)

Hinkelbein, W.; Bruggmoser, G.; Schmidt, M.; Wannenmacher, M.

1984-01-01

Compared to surgery alone, postoperative radiotherapy leads with glioblastomas (grade IV gliomas) to a significant improvement of the therapeutic results. The prolongation of survival time, however, is to a large extent compensated by the therapy itself (it normally implicates hospitalisation). Therefore, we tested the efficiency of rapid course irradiation with high fractions. 70 patients were treated daily with individual fractions of 3.5 Gy, 4 to 6 fractions per week. The entire dose amounted to 31.5 to 38.5 Gy. The average survival time was 33.5 weeks corresponding to the survival time known from the combined surgical and radiotherapeutical treatment of glioblastomas. An effective increase in therapy-free survival time seems possible, especially when the entire focal dose does not exceed 35 Gy. It is remarkable that the patients with the maximum exposure did not have the longest survival times and rates. Living conditions for the patients were similar to those with conventional fractioning, or even better. Rapid course irradiation with high fractions and a limited total dose (35 Gy) presently is - apart from the accelerated superfractioning - a successful measure to prolong the therapyfree survival time for patients with grade IV gliomas. (orig.) [de

Outcomes of Risk-Adapted Fractionated Stereotactic Radiotherapy for Stage I Non-Small-Cell Lung Cancer

International Nuclear Information System (INIS)

Lagerwaard, Frank J.; Haasbeek, Cornelis J.A.; Smit, Egbert F.; Slotman, Ben J.; Senan, S.

2008-01-01

Purpose: High local control rates can be achieved using stereotactic radiotherapy in Stage I non-small-cell lung cancer (NSCLC), but reports have suggested that toxicity may be of concern. We evaluated early clinical outcomes of 'risk-adapted' fractionation schemes in patients treated in a single institution. Methods and Materials: Of 206 patients with Stage I NSCLC, 81% were unfit to undergo surgery and the rest refused surgery. Pathologic confirmation of malignancy was obtained in 31% of patients. All other patients had new or growing 18F-fluorodeoxyglucose positron emission tomography positive lesions with radiologic characteristics of malignancy. Planning four-dimensional computed tomography scans were performed and fractionation schemes used (3 x 20 Gy, 5 x 12 Gy, and 8 x 7.5 Gy) were determined by T stage and risk of normal tissue toxicity. Results: Median overall survival was 34 months, with 1- and 2-year survivals of 81% and 64%, respectively. Disease-free survival (DFS) at 1 and 2 years was 83% and 68%, respectively, and DFS correlated with T stage (p = 0.002). Local failure was observed in 7 patients (3%). The crude regional failure rate was 9%; isolated regional recurrence was observed in 4%. The distant progression-free survival at 1 and 2 years was 85% and 77%, respectively. SRT was well tolerated and severe late toxicity was observed in less than 3% of patients. Conclusions: SRT is well tolerated in patients with extensive comorbidity with high local control rates and minimal toxicity. Early outcomes are not inferior to those reported for conventional radiotherapy. In view of patient convenience, such risk-adapted SRT schedules should be considered treatment of choice in patients presenting with medically inoperable Stage I NSCLC

Modelling the interplay between hypoxia and proliferation in radiotherapy tumour response

International Nuclear Information System (INIS)

Jeong, J; Deasy, J O; Shoghi, K I

2013-01-01

A tumour control probability computational model for fractionated radiotherapy was developed, with the goal of incorporating the fundamental interplay between hypoxia and proliferation, including reoxygenation over a course of radiotherapy. The fundamental idea is that the local delivery of oxygen and glucose limits the amount of proliferation and metabolically-supported cell survival a tumour sub-volume can support. The model has three compartments: a proliferating compartment of cells receiving oxygen and glucose; an intermediate, metabolically-active compartment receiving glucose; and a highly hypoxic compartment of starving cells. Following the post-mitotic cell death of proliferating cells, intermediate cells move into the proliferative compartment and hypoxic cells move into the intermediate compartment. A key advantage of the proposed model is that the initial compartmental cell distribution is uniquely determined from the assumed local growth fraction (GF) and volume doubling time (T D ) values. Varying initial cell state distributions, based on the local (voxel) GF and T D , were simulated. Tumour response was simulated for head and neck squamous cell carcinoma using relevant parameter values based on published sources. The tumour dose required to achieve a 50% local control rate (TCD 50 ) was found for various GFs and T D ’s, and the effect of fraction size on TCD 50 was also evaluated. Due to the advantage of reoxygenation over a course of radiotherapy, conventional fraction sizes (2–2.4 Gy fx −1 ) were predicted to result in smaller TCD 50 's than larger fraction sizes (4–5 Gy fx –1 ) for a 10 cc tumour with GFs of around 0.15. The time to eliminate hypoxic cells (the reoxygenation time) was estimated for a given GF and decreased as GF increased. The extra dose required to overcome accelerated stem cell accumulation in longer treatment schedules was estimated to be 0.68 Gy/day (in EQD2 6.6 ), similar to published values derived from clinical

Mathematical modeling of liver metastases tumour growth and control with radiotherapy

International Nuclear Information System (INIS)

Campbell, Adrienne; Sivakumaran, Thiru; Wong, Eugene; Davidson, Melanie; Lock, Michael

2008-01-01

Generating an optimized radiation treatment plan requires understanding the factors affecting tumour control. Mathematical models of tumour dynamics may help in future studies of factors predicting tumour sensitivity to radiotherapy. In this study, a time-dependent differential model, incorporating biological cancer markers, is presented to describe pre-treatment tumour growth, response to radiation, and recurrence. The model uses Gompertzian-Exponential growth to model pre-treatment tumour growth. The effect of radiotherapy is handled by a realistic cell-kill term that includes a volume-dependent change in tumour sensitivity. Post-treatment, a Gompertzian, accelerated, delayed repopulation is employed. As proof of concept, we examined the fit of the model's prediction using various liver enzyme levels as markers of metastatic liver tumour growth in a liver cancer patient. A tumour clonogen population model was formulated. Each enzyme was coupled to the same tumour population, and served as surrogates of the tumour. This dynamical model was solved numerically and compared to the measured enzyme levels. By minimizing the mean-squared error of the model enzyme predictions, we determined the following tumour model parameters: growth rate prior to treatment was 0.52% per day; the fractional radiation cell kill for the prescribed dose (60 Gy in 15 fractions) was 42% per day, and the tumour repopulation rate was 2.9% per day. These preliminary results provided the basis to test the model in a larger series of patients, to apply biological markers for improving the efficacy of radiotherapy by determining the underlying tumour dynamics.

Radiotherapy fractionation for the palliation of uncomplicated painful bone metastases – an evidence-based practice guideline

International Nuclear Information System (INIS)

Wu, Jackson Sai-Yiu; Wong, Rebecca KS; Lloyd, Nancy S; Johnston, Mary; Bezjak, Andrea; Whelan, Timothy

2004-01-01

This practice guideline was developed to provide recommendations to clinicians in Ontario on the preferred standard radiotherapy fractionation schedule for the treatment of painful bone metastases. A systematic review and meta-analysis was performed and published elsewhere. The Supportive Care Guidelines Group, a multidisciplinary guideline development panel, formulated clinical recommendations based on their interpretation of the evidence. In addition to evidence from clinical trials, the panel also considered patient convenience and ease of administration of palliative radiotherapy. External review of the draft report by Ontario practitioners was obtained through a mailed survey, and final approval was obtained from the Practice Guidelines Coordinating Committee. Meta-analysis did not detect a significant difference in complete or overall pain relief between single treatment and multifraction palliative radiotherapy for bone metastases. Fifty-nine Ontario practitioners responded to the mailed survey (return rate 62%). Forty-two percent also returned written comments. Eighty-three percent of respondents agreed with the interpretation of the evidence and 75% agreed that the report should be approved as a practice guideline. Minor revisions were made based on feedback from the external reviewers and the Practice Guidelines Coordinating Committee. The Practice Guidelines Coordinating Committee approved the final practice guideline report. For adult patients with single or multiple radiographically confirmed bone metastases of any histology corresponding to painful areas in previously non-irradiated areas without pathologic fractures or spinal cord/cauda equine compression, we conclude that: • Where the treatment objective is pain relief, a single 8 Gy treatment, prescribed to the appropriate target volume, is recommended as the standard dose-fractionation schedule for the treatment of symptomatic and uncomplicated bone metastases. Several factors frequently

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

International Nuclear Information System (INIS)

Ricardi, Umberto; Corrias, Andrea; Einaudi, Silvia; Genitori, Lorenzo; Sandri, Alessandro; Cordero Di Montezemolo, Luca; Besenzon, Luigi; Madon, Enrico; Urgesi, Alessandro

2001-01-01

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

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

International Nuclear Information System (INIS)

Harrabi, Semi B; Adeberg, Sebastian; Welzel, Thomas; Rieken, Stefan; Habermehl, Daniel; Debus, Jürgen; Combs, Stephanie E

2014-01-01

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

Multileaf collimator in radiotherapy

International Nuclear Information System (INIS)

Jeraj, M.; Robar, V.

2004-01-01

Background. Basic goal of radiotherapy treatment is the irradiation of a target volume while minimizing the amount of radiation absorbed in healthy tissue. Shaping the beam is an important way of minimizing the absorbed dose in healthy tissue and critical structures. Conventional collimator jaws are used for shaping a rectangular treatment field; but, as usually treatment volume is not rectangular, additional shaping is required. On a linear accelerator, lead blocks or individually made Cerroben TM blocks are attached onto the treatment head under standard collimating system. Another option is the use of multileaf collimator (MLC). Conclusions. Multileaf collimator is becoming the main tool for beam shaping on the linear accelerator. It is a simple and useful system in the preparation and performance of radiotherapy treatment. Multileaf collimators are reliable, as their manufacturers developed various mechanisms for their precision, control and reliability, together with reduction of leakage and transmission of radiation between and through the leaves. Multileaf collimator is known today as a very useful clinical system for simple field shaping, but its use is getting even more important in dynamic radiotherapy, with the leaves moving during irradiation. This enables a precise dose delivery on any part of a treated volume. Intensity modulated radiotherapy (IMRT), the therapy of the future, is based on the dynamic use of MLC. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

Repopulation of FaDu human squamous cell carcinoma during fractionated radiotherapy correlates with reoxygenation

International Nuclear Information System (INIS)

Petersen, Cordula; Zips, Daniel; Krause, Mechthild; Schoene, Kerstin; Eicheler, Wolfgang; Hoinkis, Cordelia; Thames, Howard D.; Baumann, Michael

2001-01-01

Purpose: FaDu human squamous cell carcinoma (FaDu-hSCC) showed a clear-cut time factor during fractionated radiotherapy (RT) under ambient blood flow. It remained unclear whether this is caused solely by proliferation or if radioresistance resulting from increasing hypoxia contributed to this phenomenon. To address this question, repopulation of clonogenic FaDu cells during fractionated RT under clamp hypoxia was determined by local tumor control assays, and compared to the results after irradiation with the same regimen under ambient blood flow. Methods and Materials: FaDu-hSCC was transplanted into the right hind leg of NMRI nu/nu mice. In the first set of experiments, irradiation was performed under clamp hypoxia. After increasing numbers of 3 Gy fractions (time intervals 24 h or 48 h), graded top-up doses were given to determine the TCD 50 (dose required to control 50% of the tumors). In the second set of experiments, all 3 Gy fractions were applied under ambient conditions, but as in the previous experiments the graded top-up doses were given under clamp hypoxia. A total of 26 TCD 50 assays were performed and analyzed using maximum likelihood techniques. Results: With increasing numbers of daily fractions, the top-up TCD 50 under clamp hypoxia decreased from 39.4 Gy [95% CI 36, 42] after single dose to 19.8 Gy [15, 24] after 18 fractions in 18 days and to 37.8 Gy [31, 44] after 18 fractions in 36 days. The results were consistent with biphasic repopulation, with a switch to rapid repopulation after about 22 days [13, 30]. The clonogen doubling time (T clon ) decreased from 9.8 days [0, 21] in the beginning of RT to 3.4 days after 22 days. Under ambient blood flow the top-up TCD 50 decreased from 37.6 Gy [34, 40] after single dose irradiation to 0 Gy [0, 1] after 18 fractions in 18 days and 22.4 Gy [18, 27] after 18 fractions in 36 days. Similar to results from irradiations under clamp hypoxia, the ambient data were consistent with a biphasic course of clonogen

Randomized Phase III Noninferiority Study Comparing Two Radiotherapy Fractionation Schedules in Patients With Low-Risk Prostate Cancer

Science.gov (United States)

Dignam, James J.; Amin, Mahul B.; Bruner, Deborah W.; Low, Daniel; Swanson, Gregory P.; Shah, Amit B.; D’Souza, David P.; Michalski, Jeff M.; Dayes, Ian S.; Seaward, Samantha A.; Hall, William A.; Nguyen, Paul L.; Pisansky, Thomas M.; Faria, Sergio L.; Chen, Yuhchyau; Koontz, Bridget F.; Paulus, Rebecca; Sandler, Howard M.

2016-01-01

Purpose Conventional radiotherapy (C-RT) treatment schedules for patients with prostate cancer typically require 40 to 45 treatments that take place from > 8 to 9 weeks. Preclinical and clinical research suggest that hypofractionation—fewer treatments but at a higher dose per treatment—may produce similar outcomes. This trial was designed to assess whether the efficacy of a hypofractionated radiotherapy (H-RT) treatment schedule is no worse than a C-RT schedule in men with low-risk prostate cancer. Patients and Methods A total of 1,115 men with low-risk prostate cancer were randomly assigned 1:1 to C-RT (73.8 Gy in 41 fractions over 8.2 weeks) or to H-RT (70 Gy in 28 fractions over 5.6 weeks). This trial was designed to establish (with 90% power and an α of .05) that treatment with H-RT results in 5-year disease-free survival (DFS) that is not worse than C-RT by more than 7.65% (H-RT/C-RT hazard ratio [HR] < 1.52). Results A total of 1,092 men were protocol eligible and had follow-up information; 542 patients were assigned to C-RT and 550 to H-RT. Median follow-up was 5.8 years. Baseline characteristics were not different according to treatment assignment. The estimated 5-year DFS was 85.3% (95% CI, 81.9 to 88.1) in the C-RT arm and 86.3% (95% CI, 83.1 to 89.0) in the H-RT arm. The DFS HR was 0.85 (95% CI, 0.64 to 1.14), and the predefined noninferiority criterion that required that DFS outcomes be consistent with HR < 1.52 was met (P < .001). Late grade 2 and 3 GI and genitourinary adverse events were increased (HR, 1.31 to 1.59) in patients who were treated with H-RT. Conclusion In men with low-risk prostate cancer, the efficacy of 70 Gy in 28 fractions over 5.6 weeks is not inferior to 73.8 Gy in 41 fractions over 8.2 weeks, although an increase in late GI/genitourinary adverse events was observed in patients treated with H-RT. PMID:27044935

Late Outcomes Following Hypofractionated Conformal Radiotherapy vs. Standard Fractionation for Localized Prostate Cancer: A Nonrandomized Contemporary Comparison

International Nuclear Information System (INIS)

Leborgne, Felix; Fowler, Jack

2009-01-01

Purpose: To study retrospectively late complications and biochemical control in patients treated with three-dimensional conformal external-beam radiotherapy for localized prostate cancer administered using hypofractionation vs. a standard fractionation regimen. The hypofractionation regimen (Hypo) was designed to avoid more late rectal reactions and to be done in half as many treatment sessions. Methods and Materials: Eighty-nine nonrandomized patients chose Hypo delivered in 20 fractions of 3 Gy (n = 52) or 3.15 Gy (n = 37) for a median overall treatment time of 33 days. One hundred thirty comparable patients were contemporaneously treated with standard fractionation to a median dose of 78 Gy delivered over 55 days. The median follow-up time was 49 months (range, 24-73 months). Results: The 5-year actuarial biochemical control rates were 96%, 84%, and 85% for low-, medium-, and high-risk disease in the Hypo group, respectively. The respective rates in the standard fractionation group were 98%, 84%, and 87%, with no statistical difference between the two groups. The rate of rectal Grade 2-4 complications was 5.5% in both treatment groups and of urinary Grade 2-4 complications was 5.6% in the Hypo and 3% in the standard group (p = 0.36). Similarly, there were no statistical differences in the rate of late complications between patients treated with 3 Gy/fraction vs. 3.15 Gy/fraction. Conclusions: Our preliminary results showed that the Hypo regimen is feasible and does not reduce biochemical control compared with standard fractionation. The incidence of late complications was not increased when the tumor normalized total doses at 2Gy/fraction was increased from 77.1 to 83.7 Gy in patients treated with either 3 or 3.15 Gy/fraction in the Hypo group, respectively.

Fractionated stereotactic radiotherapy for acoustic neuromas: A prospective monocenter study of about 158 cases

International Nuclear Information System (INIS)

Litre, Fabien; Rousseaux, Pascal; Jovenin, Nicolas; Bazin, Arnaud; Peruzzi, Philippe; Wdowczyk, Didier; Colin, Philippe

2013-01-01

Purpose: To evaluate long-term outcomes and efficacy of fractionated stereotactic radiotherapy in the treatment of acoustic neuromas. Material and methods: Between January 1996 and December 2009, 158 acoustic neuromas were treated by FSR in 155 patients. They received a dose of 50.4 Gy, with a safety margin of 1–2 mm with a median tumor volume at 2.45 mL (range: 0.17–12.5 mL) and a median follow-up duration at 60 months (range: 24–192). Results: FSR was well tolerated in all patients with mild sequelae consisting in radiation-induced trigeminal nerve impairments (3.2%), Grade 2 facial neuropathies (2.5%), new or aggravated tinnitus (2.1%) and VP shunting (2.5%). The treatment failed in four patients (2.5%) who had subsequent surgery respectively at 20, 38, 45 and 84 months post-FSR. The local tumor control rates were respectively 99.3%, 97.5% and 95.2% at 3, 5 and >7-year of follow-up. For initial Gardner–Robertson Grade 1 and 2 ANs, the preservation of useful hearing was possible in 54% of the cases; only Grade 1 ANs had stabilized during the course of the follow-up with 71% >7 years. However, hearing preservation was not correlated to the initial Koos Stage and to the radiation dose delivered to the cochlea. Tinnitus (70%), vertigo (59%), imbalance (46%) and ear mastoid pain (43%) had greatly improved post-FRS in most patients. Tumor control, hearing preservation and FRS toxicity were quite similar in patients with NF2, cystic acoustic neuroma, prior surgical resection and Koos Stage 4 AN. No secondary tumors were observed. Conclusion: FSR is a safe and effective therapeutic for acoustic neuromas and could be an alternative to microsurgery. Compared to radiosurgery, there are no contraindications for fractioned doses of stereotactic radiotherapy especially for Stage-4 tumors and patients at high risk of hearing loss

Fractionated stereotactic radiotherapy for acoustic neuromas: A prospective monocenter study of about 158 cases

Energy Technology Data Exchange (ETDEWEB)

Litre, Fabien [Hôpital Maison Blanche, Reims Cedex (France); Rousseaux, Pascal [Hôpital Maison Blanche, Reims Cedex (France); Jovenin, Nicolas [Institut Jean Godinot, Reims Cedex (France); Bazin, Arnaud; Peruzzi, Philippe [Hôpital Maison Blanche, Reims Cedex (France); Wdowczyk, Didier; Colin, Philippe [Institut du Cancer Reims Courlancy, Reims (France)

2013-02-15

Purpose: To evaluate long-term outcomes and efficacy of fractionated stereotactic radiotherapy in the treatment of acoustic neuromas. Material and methods: Between January 1996 and December 2009, 158 acoustic neuromas were treated by FSR in 155 patients. They received a dose of 50.4 Gy, with a safety margin of 1–2 mm with a median tumor volume at 2.45 mL (range: 0.17–12.5 mL) and a median follow-up duration at 60 months (range: 24–192). Results: FSR was well tolerated in all patients with mild sequelae consisting in radiation-induced trigeminal nerve impairments (3.2%), Grade 2 facial neuropathies (2.5%), new or aggravated tinnitus (2.1%) and VP shunting (2.5%). The treatment failed in four patients (2.5%) who had subsequent surgery respectively at 20, 38, 45 and 84 months post-FSR. The local tumor control rates were respectively 99.3%, 97.5% and 95.2% at 3, 5 and >7-year of follow-up. For initial Gardner–Robertson Grade 1 and 2 ANs, the preservation of useful hearing was possible in 54% of the cases; only Grade 1 ANs had stabilized during the course of the follow-up with 71% >7 years. However, hearing preservation was not correlated to the initial Koos Stage and to the radiation dose delivered to the cochlea. Tinnitus (70%), vertigo (59%), imbalance (46%) and ear mastoid pain (43%) had greatly improved post-FRS in most patients. Tumor control, hearing preservation and FRS toxicity were quite similar in patients with NF2, cystic acoustic neuroma, prior surgical resection and Koos Stage 4 AN. No secondary tumors were observed. Conclusion: FSR is a safe and effective therapeutic for acoustic neuromas and could be an alternative to microsurgery. Compared to radiosurgery, there are no contraindications for fractioned doses of stereotactic radiotherapy especially for Stage-4 tumors and patients at high risk of hearing loss.

[Current status and potential perspectives in classical radiotherapy technology].

Science.gov (United States)

Dabić-Stanković, Kata M; Stanković, Jovan B; Radosević-Jelić, Ljiljana M

2004-01-01

After purchase of radiotherapy equipment in 2003, classic radiation therapy in Serbia will reach the highest world level. In order to define the highest standards in radiation technology, we analyzed the current status and potential perspectives of radiation therapy. An analysis of present situation in the USA, assumed as the most developed in the world, was done. Available data, collected in the last 3 years (equipment assortment, therapy modalities, workload and manpower) for 284 radiotherapy centers, out of potential 2050, were analyzed. Results were presented as crude percentage and matched to point current status. The analysis showed that CLINAC accelerators are the most popular (82.7%), as well as, ADAC (43.7%) and Focus (CMS) (27.4%) systems for therapy planning. Movement towards virtual simulation is evident (59.3%), although classic "simulation" is not fully eliminated from the radiotherapy chain. The most popular brachytherapy afterloader is Microselectron HDR (71%). About 64.4% centers use IMPAC communication/verification/record system that seems more open than Varis. All centers practice modern radiotherapy modalities and techniques (CPRT, IMRT, SRS/SRT, TBI, IORT, IVBHRT, HDR BHRT, etc.). CT and MRI availability is out of question, but PET is available in 3% of centers, however this percentage is rapidly growing. Up to 350 new patients per year are treated by one accelerator (about 35 pts. a day). Centers are relatively small and utilize 2-3 accelerators on average. Average FTE staffing norm is 4 radiation oncologists, 2-3 medical radiotherapy physicists, about 3 certified medical dosimetrists and about 6 radiotherapy technologists. In the past 5 years relative stagnation in classic radiotherapy has been observed. In spite of substantial investments in technology and consequent improvements, as well as wide introduction of computers in radiotherapy, radiotherapy results have not changed significantly. Vendor developement strategies do not point that

Stability of electron-beam energy monitor for quality assurance of the electron-beam energy from radiotherapy accelerators

International Nuclear Information System (INIS)

Chida, Koichi; Zuguchi, Masayuki; Saito, Haruo; Takai, Yoshihiro; Mitsuya, Masatoshi; Sakakida, Hideharu; Yamada, Shogo; Kohzuki, Masahiro

2002-01-01

Information on electron energy is important in planning radiation therapy using electrons. The Geske 3405 electron beam energy monitor (Geske monitor, PTW Nuclear Associates, Carle Place, NY, USA) is a device containing nine ionization chambers for checking the energy of the electron beams produced by radiotherapy accelerators. We wondered whether this might increase the likelihood of ionization chamber trouble. In spite of the importance of the stability of such a quality assurance (QA) device, there are no reports on the stability of values measured with a Geske monitor. The purpose of this paper was therefore to describe the stability of a Geske monitor. It was found that the largest coefficient of variation (CV) of the Geske monitor measurements was approximately 0.96% over a 21-week period. In conclusion, the stability of Geske monitor measurements of the energy of electron beams from a linear accelerator was excellent. (author)

Late Toxicities after Conventional Radiotherapy for Nasopharyngeal Carcinoma: Incidence and Risk Factors

International Nuclear Information System (INIS)

Siala, W.; Mnejja, W.; Elloumi, F.; Daoud, J.; Ghorbel, A.; Mnif, J.; Frikha, M.

2014-01-01

Background. To determine the incidence and analyze the factors affecting late toxicity for nasopharyngeal carcinoma patients treated with conventional radiotherapy. Patients and Methods. Retrospective analysis was performed on 239 NPC patients treated between 1993 and 2004 in our institution. One hundred and fifty-seven patients were treated with conventional fractionation (2 Gy per fraction, 5 fractions per week) and eighty-two patients with hyperfractionated radiotherapy (1.6 Gy per fraction twice a day, 5 days per week). One hundred fifty nine patients underwent neoadjuvant cisplatin based chemotherapy. Late toxicity was evaluated according to the RTOG/EORTC score. Results. Xerostomia was the most common related complication (98.7%). Neoadjuvant chemotherapy and hyperfractionated radiotherapy did not increase late toxicities. Multivariate analyses showed that radiation dose was a significant factor for hearing impairment, younger age for trismus, initial node status for neck fibrosis, and initial dental hygiene for dental complications. Female gender was associated with significantly higher incidence of trismus and hearing impairment. Conclusion. Conventional radiotherapy was associated with a high rate of late toxicities which affect patients’ quality of life. With the development of three-dimensional conformal radiotherapy and intensity modulated radiotherapy, a reduced incidence of radiation related complications could be expected.

TH-CD-202-11: Implications for Online Adaptive and Non-Adaptive Radiotherapy of Gastic and Gastroesophageal Junction Cancers Using MRI-Guided Radiotherapy

International Nuclear Information System (INIS)

Mittauer, K; Geurts, M; Toya, R; Bassetti, M; Harari, P; Paliwal, B; Bayouth, J

2016-01-01

Purpose: Radiotherapy for gastric and gastroesophageal junction (GEJ) tumors commonly requires large margins due to deformation, motion and variable changes of the stomach anatomy, at the risk of increased normal tissue toxicities. This work quantifies the interfraction variation of stomach deformation from daily MRI-guided radiotherapy to allow for a more targeted determination of margin expansion in the treatment of gastric and GEJ tumors. Methods: Five patients treated for gastric (n=3) and gastroesophageal junction (n=2) cancers with conventionally fractionated radiotherapy underwent daily MR imaging on a clinical MR-IGRT system. Treatment planning and contours were performed based on the MR simulation. The stomach was re-contoured on each daily volumetric setup MR. Dice similarity coefficients (DSC) of the daily stomach were computed to evaluate the stomach interfraction deformation. To evaluate the stomach margin, the maximum Hausdorff distance (HD) between the initial and fractional stomach surface was measured for each fraction. The margin expansion, needed to encompass all fractions, was evaluated from the union of all fractional stomachs. Results: In total, 94 fractions with daily stomach contours were evaluated. For the interfraction stomach differences, the average DSC was 0.67±0.1 for gastric and 0.62±0.1 for GEJ cases. The maximum HD of each fraction was 3.5±2.0cm (n=94) with mean HD of 0.8±0.4cm (across all surface voxels for all fractions). The margin expansion required to encompass all individual fractions (averaged across 5 patients) was 1.4 cm(superior), 2.3 cm(inferior), 2.5 cm(right), 3.2 cm(left), 3.7 cm(anterior), 3.4 cm(posterior). Maximum observed difference for margin expansion was 8.7cm(posterior) among one patient. Conclusion: We observed a notable interfractional change in daily stomach shape (i.e., mean DSC of 0.67, p<0.0001) in both gastric and GEJ patients, for which adaptive radiotherapy is indicated. A minimum PTV margin of 3

TH-CD-202-11: Implications for Online Adaptive and Non-Adaptive Radiotherapy of Gastic and Gastroesophageal Junction Cancers Using MRI-Guided Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Mittauer, K; Geurts, M; Toya, R; Bassetti, M; Harari, P; Paliwal, B; Bayouth, J [University of Wisconsin, Madison, WI (United States)

2016-06-15

Purpose: Radiotherapy for gastric and gastroesophageal junction (GEJ) tumors commonly requires large margins due to deformation, motion and variable changes of the stomach anatomy, at the risk of increased normal tissue toxicities. This work quantifies the interfraction variation of stomach deformation from daily MRI-guided radiotherapy to allow for a more targeted determination of margin expansion in the treatment of gastric and GEJ tumors. Methods: Five patients treated for gastric (n=3) and gastroesophageal junction (n=2) cancers with conventionally fractionated radiotherapy underwent daily MR imaging on a clinical MR-IGRT system. Treatment planning and contours were performed based on the MR simulation. The stomach was re-contoured on each daily volumetric setup MR. Dice similarity coefficients (DSC) of the daily stomach were computed to evaluate the stomach interfraction deformation. To evaluate the stomach margin, the maximum Hausdorff distance (HD) between the initial and fractional stomach surface was measured for each fraction. The margin expansion, needed to encompass all fractions, was evaluated from the union of all fractional stomachs. Results: In total, 94 fractions with daily stomach contours were evaluated. For the interfraction stomach differences, the average DSC was 0.67±0.1 for gastric and 0.62±0.1 for GEJ cases. The maximum HD of each fraction was 3.5±2.0cm (n=94) with mean HD of 0.8±0.4cm (across all surface voxels for all fractions). The margin expansion required to encompass all individual fractions (averaged across 5 patients) was 1.4 cm(superior), 2.3 cm(inferior), 2.5 cm(right), 3.2 cm(left), 3.7 cm(anterior), 3.4 cm(posterior). Maximum observed difference for margin expansion was 8.7cm(posterior) among one patient. Conclusion: We observed a notable interfractional change in daily stomach shape (i.e., mean DSC of 0.67, p<0.0001) in both gastric and GEJ patients, for which adaptive radiotherapy is indicated. A minimum PTV margin of 3

Construction of a remote radiotherapy planning system

International Nuclear Information System (INIS)

Ogawa, Yoshihiro; Nemoto, Kenji; Takahashi, Chiaki; Takai, Yoshihiro; Yamada, Shogo; Seiji, Hiromasa; Sasaki, Kazuya

2005-01-01

We constructed a remote radiotherapy planning system, and we examined the usefulness of and faults in our system in this study. Two identical radiotherapy planning systems, one installed at our institution and the other installed at an affiliated hospital, were used for radiotherapy planning. The two systems were connected by a wide area network (WAN), using a leased line. Beam data for the linear accelerator at the affiliated hospital were installed in the two systems. During the period from December 2001 to December 2002, 43 remote radiotherapy plans were made using this system. Data were transmitted using a file transfer protocol (FTP) software program. The 43 radiotherapy plans examined in this study consisted of 13 ordinary radiotherapy plans, 28 radiotherapy plans sent to provide assistance for medical residents, and 2 radiotherapy plans for emergency cases. There were ten minor planning changes made in radiotherapy plans sent to provide assistance for medical residents. Our remote radiotherapy planning system based on WAN using a leased line is useful for remote radiotherapy, with advantages for both radiation oncologists and medical residents. (author)

Particle accelerators in the Czech lands

International Nuclear Information System (INIS)

Janovsky, I.

2007-01-01

The paper is structured as follows: A short look into history of accelerators; Particle accelerators in the Czech lands (Accelerators at the Institute of Nuclear Physics; Accelerators at the Faculty of Mathematics and Physics, Charles University; Czechoslovak betatron, accelerators for non-destructive testing and radiotherapy; Czechoslovak high-frequency linear electron accelerator; Czechoslovak-Soviet microtron; Accelerators at the State Research Institute of Textiles; Accelerators at the Kablo Vrchlabi plant; and Cyclotrons in the medical sector. (P.A.)

Fractionated stereotactically guided radiotherapy and radiosurgery in the treatment of functional and nonfunctional adenomas of the pituitary gland

International Nuclear Information System (INIS)

Milker-Zabel, Stefanie; Debus, Juergen; Thilmann, Christoph; Schlegel, Wolfgang; Wannenmacher, Michael

2001-01-01

Purpose: We evaluated survival rates and side effects after fractionated stereotactically guided radiotherapy (SCRT) and radiosurgery in patients with pituitary adenoma. Methods and Materials: Between 1989 and 1998, 68 patients were treated with FSRT (n=63) or radiosurgery (n=5) for pituitary adenomas. Twenty-six had functional and 42 had nonfunctional adenomas. Follow-up included CT/MRI, endocrinologic, and ophthalmologic examinations. Mean follow-up was 38.7 months. Seven patients received radiotherapy as primary treatment and 39 patients received it postoperatively for residual disease. Twenty-two patients were treated for recurrent disease after surgery. Mean total dose was 52.2 Gy for SCRT, and 15 Gy for radiosurgery. Results: Overall local tumor control was 93% (60/65 patients). Forty-three patients had stable disease based on CT/MRI, while 15 had a reduction of tumor volume. After FSRT, 26% with a functional adenoma had a complete remission and 19% had a reduction of hormonal overproduction after 34 months' mean. Two patients with STH-secreting adenomas had an endocrinologic recurrence, one with an ACTH-secreting adenoma radiologic recurrence, within 54 months. Reduction of visual acuity was seen in 4 patients and partial hypopituitarism in 3 patients. None of the patients developed brain radionecrosis or radiation-induced gliomas. Conclusion: Stereotactically guided radiotherapy is effective and safe in the treatment of pituitary adenomas to improve local control and reduce hormonal overproduction

Refinement of the basic treatment equivalent model to reflect radiotherapy treatment throughput using Australasian data

International Nuclear Information System (INIS)

Delaney, G.; Gebski, V.; Sydney University, NSW; Lunn, A.D.; Open University, Milton Keynes,; Oxford University, Oxford,; Lunn, M.; Oxford University, Oxford,

1999-01-01

The present study aims to develop a more sensitive basic treatment equivalent (BTE) model that still measures linear accelerator throughput and considers some of the shortcomings of the previous model. All radiation oncology departments in Australia and New Zealand were invited to participate. Departments were asked to time with a stopwatch all episodes of radiotherapy treatment over a 4-week period. Data collected for each treatment fraction included treatment intent, tumour site, patient age, Eastern Cooperative Oncology Group (ECOG) performance status, number of fields used, number of wedges used, number of junctions, number of shielding blocks used, whether the treatment was the first fraction, the use of general anaesthesia and whether port films or electronic portal imaging was used. Twenty-six departments of radiation oncology (70%) participated in this trial. A total of 7929 fractions of treatment, administered to 2424 patients, were timed. The factors found to most significantly impact on treatment duration on multivariate analysis were the type of fraction (first fraction was longer than subsequent fractions), type of beam (electrons were quicker than photons, which were quicker than mixed), number of fields, number of shields, number of junctions, number of port films and performance status (ECOG 2). The age of the patient, number of compensators and the sex of the patient were not significant. The relationships between factors were assessed, and models of measuring linear accelerator throughput which consider complexity corrections were derived. It is possible to show that linear accelerator throughput is poorly measured by just considering numbers of patients or fields treated per unit time; and that other factors that impact on treatment duration must be considered. A more sensitive model of patient throughput is suggested; but even when a large number of factors are considered, some insensitivity still remains in the model. Copyright (1999) Blackwell

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

International Nuclear Information System (INIS)

Omura, Ken; Harada, Hiroyuki; Suzuki, Haruhiko; Takeuchi, Yosuke; Hatano, Kazuo; Togawa, Takashi

2001-01-01

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)

The application of accelerator for medical therapy in Indonesia

International Nuclear Information System (INIS)

Yunasfi; Mudjiono; Irwati, Dwi; Hanifa

2003-01-01

The study of the application of accelerator for medical therapy in Indonesia was carried out. Accelerator that used for therapy is an electron lintier accelerator (Linac) which can radiate electron beam and X-ray. This study shows that there are 8 unit of Linac distributed at 6 big hospitals in Indonesia, especially in Jakarta. This study also shows that radiotherapy facilities in Indonesia is un sufficient of. Therefore, providing radiotherapy facilities for hospitals, especially the big hospitals in Indonesia is necessary

Treatment outcome in patients with vulvar cancer: comparison of concurrent radiotherapy to postoperative radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Lee, Ja Young; Kim, Sung Hwan; Kim, Ki Won; Park, Dong Choon; Yoon, Joo Hee; Yoon, Sei Chul [St. Vincent' s Hospital, The Catholic University of Korea School of Medicine, Seoul (Korea, Republic of); Yu, Mina [St. Mary' s Hospital, The Catholic University of Korea School of Medicine, Seoul (Korea, Republic of)

2012-03-15

To evaluate outcome and morbidity in patients with vulvar cancer treated with radiotherapy, concurrent chemoradiotherapy or postoperative radiotherapy. The records of 24 patients treated with radiotherapy for vulvar cancer between July 1993 and September 2009 were retrospectively reviewed. All patients received once daily 1.8-4 Gy fractions external beam radiotherapy to median 51.2 Gy (range, 19.8 to 81.6 Gy) on pelvis and inguinal nodes. Seven patients were treated with primary concurrent chemoradiotherapy, one patient was treated with primary radiotherapy alone, four patients received palliative radiotherapy, and twelve patients were treated with postoperative radiotherapy. Twenty patients were eligible for response evaluation. Response rate was 55% (11/20). The 5-year disease free survival was 42.2% and 5-year overall survival was 46.2%, respectively. Fifty percent (12/24) experienced with acute skin complications of grade III or more during radiotherapy. Late complications were found in 8 patients. 50% (6/12) of patients treated with lymph node dissection experienced severe late complications. One patient died of sepsis from lymphedema. However, only 16.6% (2/12) of patients treated with primary radiotherapy developed late complications. Outcome of patients with vulvar cancer treated with radiotherapy showed relatively good local control and low recurrence. Severe late toxicities remained higher in patients treated with both node dissection and radiotherapy.

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

International Nuclear Information System (INIS)

Eltayeb, A.E.H.

2009-02-01

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 37 o C 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 37 o C 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

Modelling altered fractionation schedules

International Nuclear Information System (INIS)

Fowler, J.F.

1993-01-01

The author discusses the conflicting requirements of hyperfractionation and accelerated fractionation used in radiotherapy, and the development of computer modelling to predict how to obtain an optimum of tumour cell kill without exceeding normal-tissue tolerance. The present trend is to shorten hyperfractionated schedules from 6 or 7 weeks to give overall times of 4 or 5 weeks as in new schedules by Herskovic et al (1992) and Harari (1992). Very high doses are given, much higher than can be given when ultrashort schedules such as CHART (12 days) are used. Computer modelling has suggested that optimum overall times, to yield maximum cell kill in tumours ((α/β = 10 Gy) for a constant level of late complications (α/β = 3 Gy) would be X or X-1 weeks, where X is the doubling time of the tumour cells in days (Fowler 1990). For median doubling times of about 5 days, overall times of 4 or 5 weeks should be ideal. (U.K.)

Different rectal toxicity tolerance with and without simultaneous conventionally-fractionated pelvic lymph node treatment in patients receiving hypofractionated prostate radiotherapy

International Nuclear Information System (INIS)

McDonald, Andrew M; Baker, Christopher B; Popple, Richard A; Shekar, Kiran; Yang, Eddy S; Jacob, Rojymon; Cardan, Rex; Kim, Robert Y; Fiveash, John B

2014-01-01

To investigate added morbidity associated with the addition of pelvic elective nodal irradiation (ENI) to hypofractionated radiotherapy to the prostate. Two-hundred twelve patients, treated with hypofractionated radiotherapy to the prostate between 2004 and 2011, met the inclusion criteria for the analysis. All patients received 70 Gy to the prostate delivered over 28 fractions and 103 (49%) received ENI consisting of 50.4 Gy to the pelvic lymphatics delivered simultaneously in 1.8 Gy fractions. The mean dose-volume histograms were compared between the two subgroups defined by use of ENI, and various dose-volume parameters were analyzed for effect on late lower gastrointestinal (GI) and genitourinary (GU) toxicity. Acute grade 2 lower GI toxicity occurred in 38 (37%) patients receiving ENI versus 19 (17%) in those who did not (p = 0.001). The Kaplan-Meier estimate of grade ≥ 2 lower GI toxicity at 3 years was 15.3% for patients receiving ENI versus 5.3% for those who did not (p = 0.026). Each rectal isodose volume was increased for patients receiving ENI up to 50 Gy (p ≤ 0.021 for each 5 Gy increment). Across all patients, the absolute V 70 of the rectum was the only predictor of late GI toxicity. When subgroups, defined by the use of ENI, were analyzed separately, rectal V 70 was only predictive of late GI toxicity for patients who received ENI. For patients receiving ENI, V 70 > 3 cc was associated with an increased risk of late GI events. Elective nodal irradiation increases the rates of acute and late GI toxicity when delivered simultaneously with hypofractioanted prostate radiotherapy. The use of ENI appears to sensitize the rectum to hot spots, therefore we recommend added caution to minimize the volume of rectum receiving 100% of the prescription dose in these patients

Different rectal toxicity tolerance with and without simultaneous conventionally-fractionated pelvic lymph node treatment in patients receiving hypofractionated prostate radiotherapy.

Science.gov (United States)

McDonald, Andrew M; Baker, Christopher B; Popple, Richard A; Shekar, Kiran; Yang, Eddy S; Jacob, Rojymon; Cardan, Rex; Kim, Robert Y; Fiveash, John B

2014-06-03

To investigate added morbidity associated with the addition of pelvic elective nodal irradiation (ENI) to hypofractionated radiotherapy to the prostate. Two-hundred twelve patients, treated with hypofractionated radiotherapy to the prostate between 2004 and 2011, met the inclusion criteria for the analysis. All patients received 70 Gy to the prostate delivered over 28 fractions and 103 (49%) received ENI consisting of 50.4 Gy to the pelvic lymphatics delivered simultaneously in 1.8 Gy fractions. The mean dose-volume histograms were compared between the two subgroups defined by use of ENI, and various dose-volume parameters were analyzed for effect on late lower gastrointestinal (GI) and genitourinary (GU) toxicity. Acute grade 2 lower GI toxicity occurred in 38 (37%) patients receiving ENI versus 19 (17%) in those who did not (p = 0.001). The Kaplan-Meier estimate of grade ≥ 2 lower GI toxicity at 3 years was 15.3% for patients receiving ENI versus 5.3% for those who did not (p = 0.026). Each rectal isodose volume was increased for patients receiving ENI up to 50 Gy (p ≤ 0.021 for each 5 Gy increment). Across all patients, the absolute V70 of the rectum was the only predictor of late GI toxicity. When subgroups, defined by the use of ENI, were analyzed separately, rectal V70 was only predictive of late GI toxicity for patients who received ENI. For patients receiving ENI, V70 > 3 cc was associated with an increased risk of late GI events. Elective nodal irradiation increases the rates of acute and late GI toxicity when delivered simultaneously with hypofractioanted prostate radiotherapy. The use of ENI appears to sensitize the rectum to hot spots, therefore we recommend added caution to minimize the volume of rectum receiving 100% of the prescription dose in these patients.

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

Energy Technology Data Exchange (ETDEWEB)

Kazi, Rehan [Head and Neck Unit, Royal Marsden Hospital, London (United Kingdom); Institute of Cancer Research, Cancer Research UK Centre for Cell and Molecular Biology, London (United Kingdom); Venkitaraman, Ramachandran; Johnson, Catherine; Prasad, Vyas; Clarke, Peter; Newbold, Kate; Rhys-Evans, Peter; Nutting, Christopher [Head and Neck Unit, Royal Marsden Hospital, London (United Kingdom); Harrington, Kevin [Head and Neck Unit, Royal Marsden Hospital, London (United Kingdom); Institute of Cancer Research, Cancer Research UK Centre for Cell and Molecular Biology, London (United Kingdom)], E-mail: kevinh@icr.ac.uk

2008-05-15

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.

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

International Nuclear Information System (INIS)

Kazi, Rehan; Venkitaraman, Ramachandran; Johnson, Catherine; Prasad, Vyas; Clarke, Peter; Newbold, Kate; Rhys-Evans, Peter; Nutting, Christopher; Harrington, Kevin

2008-01-01

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

A GPU-accelerated semi-implicit fractional-step method for numerical solutions of incompressible Navier-Stokes equations

Science.gov (United States)

Ha, Sanghyun; Park, Junshin; You, Donghyun

2018-01-01

Utility of the computational power of Graphics Processing Units (GPUs) is elaborated for solutions of incompressible Navier-Stokes equations which are integrated using a semi-implicit fractional-step method. The Alternating Direction Implicit (ADI) and the Fourier-transform-based direct solution methods used in the semi-implicit fractional-step method take advantage of multiple tridiagonal matrices whose inversion is known as the major bottleneck for acceleration on a typical multi-core machine. A novel implementation of the semi-implicit fractional-step method designed for GPU acceleration of the incompressible Navier-Stokes equations is presented. Aspects of the programing model of Compute Unified Device Architecture (CUDA), which are critical to the bandwidth-bound nature of the present method are discussed in detail. A data layout for efficient use of CUDA libraries is proposed for acceleration of tridiagonal matrix inversion and fast Fourier transform. OpenMP is employed for concurrent collection of turbulence statistics on a CPU while the Navier-Stokes equations are computed on a GPU. Performance of the present method using CUDA is assessed by comparing the speed of solving three tridiagonal matrices using ADI with the speed of solving one heptadiagonal matrix using a conjugate gradient method. An overall speedup of 20 times is achieved using a Tesla K40 GPU in comparison with a single-core Xeon E5-2660 v3 CPU in simulations of turbulent boundary-layer flow over a flat plate conducted on over 134 million grids. Enhanced performance of 48 times speedup is reached for the same problem using a Tesla P100 GPU.

Radiotherapy and oral cancer

Energy Technology Data Exchange (ETDEWEB)

Sealy, R [Cape Town Univ. (South Africa). Dept. of Radiotherapy

1982-08-01

A general review article for the non-radiotherapist. The historical, physical and biological background is briefly reviewed. Mention is made of the effects of fraction size, hyperbaric oxygen, neutron beams and radiation sensitizers. The use of chemotherapy and radiotherapy is discussed, as well as the selection of patients for radiotherapy and the treatment of neck nodes. The author suggests a therapeutic approach to the various disease sites and finally reviews some of the literature on radiation caries and jaw necrosis.

Altered fractionation of hemithorax irradiation for pleural mesothelioma and failure patterns after treatment

Energy Technology Data Exchange (ETDEWEB)

Holsti, L.R. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Pyrhoenen, S. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Kajanti, M. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Maentylae, M. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Mattson, K. [Dept. of Internal Medicine, Div. of Pulmonary Medicine, Helsinki University Central Hospital (Finland); Maasilta, P. [Dept. of Internal Medicine, Div. of Pulmonary Medicine, Helsinki University Central Hospital (Finland); Kivisaari, L. [Dept. of Diagnostic Radiology, Helsinki University Central Hospital (Finland)

1997-09-01

Malignant pleural mesothelioma is a rare malignancy with a bleak prognosis. The role of radiotherapy has not yet been clarified. Our aim was to study the effect of altered fractionation on mesothelioma. We have treated 57 patients, 41 males and 16 females, with hemithorax irradiation with six different fractionation schedules. All the patients have been included in a combined modality program consisting of surgery followed by chemotherapy and finally by hemithorax irradiation. The radiotherapy schedules used were: I. Conventional fractionation of 20 Gy in 10 fractions over 12 days. II, Split-course radiotherapy 55 Gy in 25 fractions of 2.2 Gy over 7 weeks (a two weeks rest halfways) followed by a boost dose of 15 Gy over 8 days to the major tumour area. III. Hyperfractionation of 70 Gy over 7 weeks, 1.25 Gy BID with a 6-h interval and a 10-day rest halfways. IV. Combined hyperfractionation and hypofractionation, 35 Gy hyperfractionation in 28 fractions (1.25 Gy BID with a 6-h interval) over three weeks followed by 36 Gy hypofractionation 9 fractions of 4 Gy given every other day over 3 weeks to the major tumour areas only. V. Hypofractionation of 38.5 Gy over 15 days (9x3.5 Gy). VI. Combined conventional radiotherapy and hypofractionation with 20 Gy given conventionally in 10 fractions followed by 10 fractions of 3 Gy over two weeks, overall time 4 weeks. The 2-year survival rate of all patients was 21% and the 5-year survival rate 9%. Two patients are still alive more than 6 and 9 years after radiotherapy. Progression occurred after surgery in four patients, during and after chemotherapy in 22 patients and after completed radiotherapy in 29 patients. The pattern of progression was similar in each treatment group. (orig.).

Value of conventionally fractionated radiotherapy for the local treatment of HIV associated Kaposi's sarcoma

International Nuclear Information System (INIS)

Saran, F.; Adamietz, I.A.; Mose, S.; Thilmann, C.; Boettcher, H.D.

1995-01-01

From June 1991 to June 1993, 43 patients with 111 HIV-associated Kaposi's sarcoma of the skin or oral cavity were treated. Lesions were irradiated with 5 to 12 MeV electrons or 60Co gamma-rays. The fractionation scheme was 5 times 2 Gy/week for skin and enoral lesions with a total reference dosage of up to 20 Gy. Side effects were assessed during therapy and the therapeutic result 6 weeks after end of treatment. Thirty-eight out of 111 lesions were judged as complete response (CR) (34%), 61/111 as partial response (PR) (55%) and 12/111 were judged as no change (NC) (11%). Overall response (CR + PR) was 89%. Two patients with lesions of oral cavity suffered from RTOG grade-IV mucositis after 10 and 14 Gy. In 71/106 skin lesions (67%), radiation induced RTOG grade-I reactions were observed. Conclusion: In patients with HIV associated Kaposi's sarcoma effective palliation can be achieved by means of radiotherapy with an overall dose of 20 Gy in conventional fractionation. Yet, the fraction of patients with complete responses is with 34 to 47% lower compared with doses above 20 Gy (66 to 100%). With reference to the reported data our results point to a dose-response relationship for Kaposi's sarcoma. Therefore higher total reference doses, e.g. 30 Gy with weekly 5 times 2 Gy or 24 Gy with 5 times 1.6 Gy for mucous lesions, respectively, are suggested as by this mean the complete response rate can be coubled. (orig./MG) [de

Radiotherapy fractionation for the palliation of uncomplicated painful bone metastases – an evidence-based practice guideline

Directory of Open Access Journals (Sweden)

Bezjak Andrea

2004-10-01

Full Text Available Abstract Background This practice guideline was developed to provide recommendations to clinicians in Ontario on the preferred standard radiotherapy fractionation schedule for the treatment of painful bone metastases. Methods A systematic review and meta-analysis was performed and published elsewhere. The Supportive Care Guidelines Group, a multidisciplinary guideline development panel, formulated clinical recommendations based on their interpretation of the evidence. In addition to evidence from clinical trials, the panel also considered patient convenience and ease of administration of palliative radiotherapy. External review of the draft report by Ontario practitioners was obtained through a mailed survey, and final approval was obtained from the Practice Guidelines Coordinating Committee. Results Meta-analysis did not detect a significant difference in complete or overall pain relief between single treatment and multifraction palliative radiotherapy for bone metastases. Fifty-nine Ontario practitioners responded to the mailed survey (return rate 62%. Forty-two percent also returned written comments. Eighty-three percent of respondents agreed with the interpretation of the evidence and 75% agreed that the report should be approved as a practice guideline. Minor revisions were made based on feedback from the external reviewers and the Practice Guidelines Coordinating Committee. The Practice Guidelines Coordinating Committee approved the final practice guideline report. Conclusion For adult patients with single or multiple radiographically confirmed bone metastases of any histology corresponding to painful areas in previously non-irradiated areas without pathologic fractures or spinal cord/cauda equine compression, we conclude that: • Where the treatment objective is pain relief, a single 8 Gy treatment, prescribed to the appropriate target volume, is recommended as the standard dose-fractionation schedule for the treatment of symptomatic and

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

International Nuclear Information System (INIS)

Jimenez, Marcelo F.; Baardwijk, Angela van; Aerts, Hugo J.W.L.; De Ruysscher, Dirk; Novoa, Nuria M.; Varela, Gonzalo; Lambin, Philippe

2010-01-01

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.

First symposium accelerated partial breast irradiation

International Nuclear Information System (INIS)

2012-01-01

The First symposium accelerated partial breast irradiation, was organized by the Marie Curie Foundation, between the 14 to 16 june 2012, in the Cordoba city of Argentina. In this event were presented some papers on the following topics: radiotherapy in breast cancer; interaction between systemic treatments and radiotherapy; interstitial brachytherapy.

Inter-fraction variations in respiratory motion models

Energy Technology Data Exchange (ETDEWEB)

McClelland, J R; Modat, M; Ourselin, S; Hawkes, D J [Centre for Medical Image Computing, University College London (United Kingdom); Hughes, S; Qureshi, A; Ahmad, S; Landau, D B, E-mail: j.mcclelland@cs.ucl.ac.uk [Department of Oncology, Guy' s and St Thomas' s Hospitals NHS Trust, London (United Kingdom)

2011-01-07

Respiratory motion can vary dramatically between the planning stage and the different fractions of radiotherapy treatment. Motion predictions used when constructing the radiotherapy plan may be unsuitable for later fractions of treatment. This paper presents a methodology for constructing patient-specific respiratory motion models and uses these models to evaluate and analyse the inter-fraction variations in the respiratory motion. The internal respiratory motion is determined from the deformable registration of Cine CT data and related to a respiratory surrogate signal derived from 3D skin surface data. Three different models for relating the internal motion to the surrogate signal have been investigated in this work. Data were acquired from six lung cancer patients. Two full datasets were acquired for each patient, one before the course of radiotherapy treatment and one at the end (approximately 6 weeks later). Separate models were built for each dataset. All models could accurately predict the respiratory motion in the same dataset, but had large errors when predicting the motion in the other dataset. Analysis of the inter-fraction variations revealed that most variations were spatially varying base-line shifts, but changes to the anatomy and the motion trajectories were also observed.

Particle-beam accelerators for radiotherapy and radioisotopes

International Nuclear Information System (INIS)

Boyd, T.J.; Crandall, K.R.; Hamm, R.W.

1981-01-01

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

Analysis of oral cancer treated by preoperative radiotherapy

International Nuclear Information System (INIS)

Hosokawa, Yoichiro; Kaneko, Masayuki; Yasuda, Motoaki

1997-01-01

Fifty-eight patients with squamous cell carcinoma of the oral region, treated by preoperative radiotherapy between January 1988 and December 1993, were reviewed to evaluate the relation between prognosis and pathological findings after preoperative radiotherapy. All patients underwent external radiotherapy of up to 40 Gy in 16 fractions (2.5 Gy a day, 4 fractions a week) before surgery, and the average term from the end of preoperative radiotherapy to surgery were 27.3 days. According to pathological findings during surgery, the patients were divided into a radiation effective group and a radiation noneffective group. There was a significant difference in the survival rates of the two groups, but there was no difference in local control rates. After surgery, regional lymph node metastasis and distant metastasis were more common in the radiation noneffective group than in the radiation effective group. It was considered that regional lymph node metastasis after treatment in the noneffective group is the determining factor in the progress. (author)

A phase II study of hyperfractionated accelerated radiotherapy (HART) after induction cisplatin (CDDP) and vinorelbine (VNR) for stage III Non-small-cell lung cancer (NSCLC)

International Nuclear Information System (INIS)

Ishikura, Satoshi; Ohe, Yuichiro; Nihei, Keiji; Kubota, Kaoru; Kakinuma, Ryutaro; Ohmatsu, Hironobu; Goto, Koichi; Niho, Seiji; Nishiwaki, Yutaka; Ogino, Takashi

2005-01-01

Purpose: The purpose was to assess the feasibility and efficacy of hyperfractionated accelerated radiotherapy (HART) after induction chemotherapy for Stage III non-small-cell lung cancer. Methods and materials: Treatment consisted of 2 cycles of cisplatin 80 mg/m 2 on Day 1 and vinorelbine 25 mg/m 2 on Days 1 and 8 every 3 weeks followed by HART, 3 times a day (1.5, 1.8, 1.5 Gy, 4-h interval) for a total dose of 57.6 Gy. Results: Thirty patients were eligible. Their median age was 64 years (range, 46-73 years), 24 were male, 6 were female, 8 had performance status (PS) 0, 22 had PS 1, 9 had Stage IIIA, and 21 had Stage IIIB. All but 1 patient completed the treatment. Common grade ≥3 toxicities during the treatment included neutropenia, 25; infection, 5; esophagitis, 5; and radiation pneumonitis, 3. The overall response rate was 83%. The median survival was 24 months (95% confidence interval [CI], 13-34 months), and the 2-year overall survival was 50% (95% CI, 32-68%). The median progression-free survival was 10 months (95% CI, 8-20 months). Conclusion: Hyperfractionated accelerated radiotherapy after induction of cisplatin and vinorelbine was feasible and promising. Future investigation employing dose-intensified radiotherapy in combination with chemotherapy is needed

Protocol for the isotoxic intensity modulated radiotherapy (IMRT) in stage III non-small cell lung cancer (NSCLC): a feasibility study.

Science.gov (United States)

Haslett, Kate; Franks, Kevin; Hanna, Gerard G; Harden, Susan; Hatton, Matthew; Harrow, Stephen; McDonald, Fiona; Ashcroft, Linda; Falk, Sally; Groom, Nicki; Harris, Catherine; McCloskey, Paula; Whitehurst, Philip; Bayman, Neil; Faivre-Finn, Corinne

2016-04-15

The majority of stage III patients with non-small cell lung cancer (NSCLC) are unsuitable for concurrent chemoradiotherapy, the non-surgical gold standard of care. As the alternative treatment options of sequential chemoradiotherapy and radiotherapy alone are associated with high local failure rates, various intensification strategies have been employed. There is evidence to suggest that altered fractionation using hyperfractionation, acceleration, dose escalation, and individualisation may be of benefit. The MAASTRO group have pioneered the concept of 'isotoxic' radiotherapy allowing for individualised dose escalation using hyperfractionated accelerated radiotherapy based on predefined normal tissue constraints. This study aims to evaluate whether delivering isotoxic radiotherapy using intensity modulated radiotherapy (IMRT) is achievable. Isotoxic IMRT is a multicentre feasibility study. From June 2014, a total of 35 patients from 7 UK centres, with a proven histological or cytological diagnosis of inoperable NSCLC, unsuitable for concurrent chemoradiotherapy will be recruited. A minimum of 2 cycles of induction chemotherapy is mandated before starting isotoxic radiotherapy. The dose of radiation will be increased until one or more of the organs at risk tolerance or the maximum dose of 79.2 Gy is reached. The primary end point is feasibility, with accrual rates, local control and overall survival our secondary end points. Patients will be followed up for 5 years. The study has received ethical approval (REC reference: 13/NW/0480) from the National Research Ethics Service (NRES) Committee North West-Greater Manchester South. The trial is conducted in accordance with the Declaration of Helsinki and Good Clinical Practice (GCP). The trial results will be published in a peer-reviewed journal and presented internationally. NCT01836692; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence

Hypofractionated Adjuvant Whole Breast Radiotherapy: Progress and Prospects

International Nuclear Information System (INIS)

Yarnold, John; Haviland, Joanne

2010-01-01

Published results of randomised trials involving >7000 women confirm the safety and efficacy of hypofractionated schedules of adjuvant radiotherapy for women with early breast cancer using fraction sizes between 2 and 3 Gy assuming appropriate downward adjustments to total dose. Unnecessary concerns relating to heart tolerance, suboptimal dose distribution and duration of follow up need not discourage the routine adoption of 15- or 16-fraction schedules in women treated by breast conservation surgery for early breast cancer. Regardless of fractionation regimen, dose escalation to the index quadrant in high risk subgroups will result in a greater relative increase in late adverse effects than tumour control, a therapeutic disadvantage that can only be overcome by exploiting a marked dose-volume effect. A 15-fraction schedule of whole breast radiotherapy is unlikely to represent the lower limits of hypofractionation, and the preliminary results of a 5-fraction regimen are encouraging

The Quality of Curative-intent Radiotherapy for Non-small Cell Lung Cancer in the UK.

Science.gov (United States)

McAleese, J; Baluch, S; Drinkwater, K

2015-09-01

Lung cancer is the leading cause of cancer-related death in the UK. The quality of curative-intent radiotherapy is associated with better outcomes. National quality standards from the National Institute for Health and Care Excellence (NICE) on patient work-up and treatment selection were used, with guidance from the Royal College of Radiologists on the technical delivery of radiotherapy, to assess the quality of curative-intent non-small cell lung cancer radiotherapy and to describe current UK practice. Radiotherapy departments completed one questionnaire for each patient started on curative-intent radiotherapy for 8 weeks in 2013. Eighty-two per cent of centres returned a total of 317 proformas. Patient selection with positron emission tomography/computed tomography, performance status and Forced Expiratory Volume in 1 second (FEV1) was usually undertaken. Fifty-six per cent had pathological confirmation of mediastinal lymph nodes and 22% staging brain scans; 20% were treated with concurrent chemoradiation, 12% with Stereotactic Ablative Radiotherapy (SABR) and 8% with Continuous Hyperfractionated Accelerated Radiotherapy (CHART). Sixty-three per cent of patients received 55 Gy/20 fractions. Although respiratory compensation was routinely undertaken, only 33% used four-dimensional computed tomography. Seventy per cent of patients were verified with cone beam computed tomography. There was consistency of practice in dosimetric constraints for organs at risk and follow-up. This audit has described current UK practice. The latest recommendations for patient selection with pathological confirmation of mediastinal lymph nodes, brain staging and respiratory function testing are not universally followed. Although there is evidence of increasing use of newer techniques such as four-dimensional computed tomography and cone beam image-guided radiotherapy, there is still variability in access. Efforts should be made to improve access to modern technologies and quality

Theory, simulation and experiments for precise deflection control of radiotherapy electron beams

Energy Technology Data Exchange (ETDEWEB)

Figueroa, R.; Leiva, J.; Moncada, R.; Rojas, L.; Santibanez, M.; Valente, M.; Young, H. [Universidad de la Frontera, Centro de Fisica e Ingenieria en Medicina, Av. Francisco Salazar 1145, Casilla 54-D, Temuco (Chile); Velasquez, J. [Universidad de la Frontera, Departamento de Ciencias Fisicas, Av. Francisco Salazar 1145, Casilla 54-D, Temuco (Chile); Zelada, G. [Clinica Alemana de Santiago, Av. Vitacura 5951, 13132 Vitacura, Santiago (Chile); Astudillo, R., E-mail: rodolfo.figueroa@ufrontera.cl [Hospital Base de Valdivia, C. Simpson 850, XIV Region de los Rios, Valdivia (Chile)

2017-10-15

Conventional radiotherapy is mainly applied by linear accelerators. Although linear accelerators provide dual (electron/photon) radiation beam modalities, both of them are intrinsically produced by a megavoltage electron current. Modern radiotherapy treatment techniques are based on suitable devices inserted or attached to conventional linear accelerators. Thus, precise control of delivered beam becomes a main key issue. This work presents an integral description of electron beam deflection control as required for novel radiotherapy technique based on convergent photon beam production. Theoretical and Monte Carlo approaches were initially used for designing and optimizing devices components. Then, dedicated instrumentation was developed for experimental verification of electron beam deflection due to the designed magnets. Both Monte Carlo simulations and experimental results support the reliability of electrodynamics models used for predict megavoltage electron beam control. (Author)

Theory, simulation and experiments for precise deflection control of radiotherapy electron beams

International Nuclear Information System (INIS)

Figueroa, R.; Leiva, J.; Moncada, R.; Rojas, L.; Santibanez, M.; Valente, M.; Young, H.; Velasquez, J.; Zelada, G.; Astudillo, R.

2017-10-01

Conventional radiotherapy is mainly applied by linear accelerators. Although linear accelerators provide dual (electron/photon) radiation beam modalities, both of them are intrinsically produced by a megavoltage electron current. Modern radiotherapy treatment techniques are based on suitable devices inserted or attached to conventional linear accelerators. Thus, precise control of delivered beam becomes a main key issue. This work presents an integral description of electron beam deflection control as required for novel radiotherapy technique based on convergent photon beam production. Theoretical and Monte Carlo approaches were initially used for designing and optimizing devices components. Then, dedicated instrumentation was developed for experimental verification of electron beam deflection due to the designed magnets. Both Monte Carlo simulations and experimental results support the reliability of electrodynamics models used for predict megavoltage electron beam control. (Author)

Conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas

International Nuclear Information System (INIS)

Fuss, Martin; Debus, Juergen; Lohr, Frank; Huber, Peter; Rhein, Bernhard; Engenhart-Cabillic, Rita; Wannenmacher, Michael

2000-01-01

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.

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

Energy Technology Data Exchange (ETDEWEB)

Omura, Ken; Harada, Hiroyuki [Tokyo Medical and Dental Univ. (Japan). Graduate School; Suzuki, Haruhiko; Takeuchi, Yosuke; Hatano, Kazuo; Togawa, Takashi

2001-11-01

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{center_dot}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)

Dosimetric Feasibility of Hypofractionated Proton Radiotherapy for Neoadjuvant Pancreatic Cancer Treatment

International Nuclear Information System (INIS)

Kozak, Kevin R.; Kachnic, Lisa A.; Adams, Judith C; Crowley, Elizabeth M.; Alexander, Brian M.; Mamon, Harvey J.; Fernandez-Del Castillo, Carlos; Ryan, David P.; DeLaney, Thomas F.; Hong, Theodore S.

2007-01-01

Purpose: To evaluate tumor and normal tissue dosimetry of a 5 cobalt gray equivalent (CGE) x 5 fraction proton radiotherapy schedule, before initiating a clinical trial of neoadjuvant, short-course proton radiotherapy for pancreatic adenocarcinoma. Methods and Materials: The first 9 pancreatic cancer patients treated with neoadjuvant intensity-modulated radiotherapy (1.8 Gy x 28) at the Massachusetts General Hospital had treatment plans generated using a 5 CGE x 5 fraction proton regimen. To facilitate dosimetric comparisons, clinical target volumes and normal tissue volumes were held constant. Plans were optimized for target volume coverage and normal tissue sparing. Results: Hypofractionated proton and conventionally fractionated intensity-modulated radiotherapy plans both provided acceptable target volume coverage and dose homogeneity. Improved dose conformality provided by the hypofractionated proton regimen resulted in significant sparing of kidneys, liver, and small bowel, evidenced by significant reductions in the mean doses, expressed as percentage prescribed dose, to these structures. Kidney and liver sparing was most evident in low-dose regions (≤20% prescribed dose for both kidneys and ≤60% prescribed dose for liver). Improvements in small-bowel dosimetry were observed in high- and low-dose regions. Mean stomach and duodenum doses, expressed as percentage prescribed dose, were similar for the two techniques. Conclusions: A proton radiotherapy schedule consisting of 5 fractions of 5 CGE as part of neoadjuvant therapy for adenocarcinoma of the pancreas seems dosimetrically feasible, providing excellent target volume coverage, dose homogeneity, and normal tissue sparing. Hypofractionated proton radiotherapy in this setting merits Phase I clinical trial investigation

Hypofractionated radiotherapy as local hemostatic agent in advanced cancer

Directory of Open Access Journals (Sweden)

Malik Tariq Rasool

2011-01-01

Full Text Available Purpose : Tumor bleeding continues to remain a challenge in an oncological setting, and radiotherapy has been studied as a local hemostatic agent. We studied the role of local radiotherapy in controlling bleeding at our center. Materials and Methods : We reviewed 25 treated cases (cancer urinary bladder: 12, lung cancer: 5, cervical cancer: 4, uterine cancer: 1, rectal cancer: 2, schwanoma: 1 at our center from March 2008 to December 2010. All patients had either an advanced or recurrent disease. Radiotherapy schedule was either 20 Gray in 5 fractions or 15 Gray in 5 fractions and was delivered with Cobalt 60. Results and Conclusion : Of 25 patients, 22 (88% responded, and there was complete cessation of bleeding. Both 15 Gray and 20 Gray dose schedule had equal efficacy. Treatment was well tolerated without any intermission. Radiotherapy is a safe and effective option in controlling tumor bleeding.

An anti-angiogenic agent (TNP-470) inhibited reoxygenation during fractionated radiotherapy of murine mammary carcinoma

International Nuclear Information System (INIS)

Rumi, Murata; Yasumasa, Nishimura; Masahiro, Hiraoka

1996-01-01

Purpose: Angio genesis is one of the important factors for tumor growth. Therefore, an angio genesis inhibitor might decelerate tumor repopulation and is expected to improve the tumor control rate in fractionated radiotherapy (RT). On the other hand, it might increase hypoxic fraction of tumors or inhibit tumor reoxygenation during fractionated RT. This study investigated the effects of an angio genesis inhibitor on fractionated RT. Materials and Methods: Animal-tumors were early generation iso transplants of mammary carcinoma in C3H/He mice. Tumor response was studied by tumor growth (TG) time and TCD-50 (50% tumor control dose) assays. Treatments were started when tumors on the right paw grew 4-5 mm in diameter. Radiation was locally given to tumors in air or under hypoxic condition. An angio genesis inhibitor, TNP-470, a synthetic analogue of fumagillin which is a natural product of Aspergillus fumigatus, has been reported to inhibit endothelial cell growth in vitro. TNP-470 was administered s.c. twice a week at a dose of 100mg/kg. In the TG time assay, fractionated RT was delivered daily for 5 days to a total dose of 10Gy (2Gy/fraction x 5). Two or four doses of TNP-470 were administered during and/or after fractionated RT. The time required for a tumor to reach 3-fold of initial tumor volume (TG time) was determined for each group. In the TCD-50 assay, a single or fractionated irradiation was given alone or in combination with TNP-470. Fractionated irradiation was delivered daily, five times per week, over two weeks (10 fractions). One dose of TNP-470 was administered 24 h prior to a single dose of irradiation, whereas four doses of TNP-470 were given during fractionated RT. Tumors were observed for recurrence once a week for 120 days following the end of RT. Results: The TG time for no treatment group, a group treated with fractionated RT alone, or two doses of TNP-470 alone was 5.3 days (95% confidence limits: 4.8-5.9), 15.6 days (15.1-16.1) or 7.8 days (7

Feasibility and efficacy of helical intensity-modulated radiotherapy for stage III non-small cell lung cancer in comparison with conventionally fractionated 3D-CRT.

Science.gov (United States)

He, Jian; Huang, Yan; Chen, Yixing; Shi, Shiming; Ye, Luxi; Hu, Yong; Zhang, Jianying; Zeng, Zhaochong

2016-05-01

The standard treatment for stage III non-small-cell lung cancer (NSCLC) is still 60 Gy in conventional fractions combined with concurrent chemotherapy; however, the resulting local controls are disappointing. The aim of this study was to compare and assess the feasibility and efficacy of hypofractionated chemoradiotherapy using helical tomotherapy (HT) with conventional fractionation as opposed to using three-dimensional conformal radiotherapy (3D-CRT) for stage III NSCLC. Sixty-nine patients with stage III (AJCC 7th edition) NSCLC who underwent definitive radiation treatment at our institution between July 2011 and November 2013 were reviewed and analyzed retrospectively. A dose of 60 Gy in 20 fractions was delivered in the HT group (n=34), whereas 60 Gy in 30 fractions in the 3D-CRT group (n=35). Primary endpoints were toxicity, overall response rate, overall survival (OS) and progression-free survival (PFS). The median follow-up period was 26.4 months. V20 (P=0.005), V30 (P=0.001), V40 (P=0.004), mean lung dose (P=0.000) and max dose of spinal cord (P=0.005) were significantly lower in the HT group than in the 3D-CRT group. There was no significant difference in the incidences of acute radiation pneumonitis (RP) ≥ grade 2 between the two groups, whereas the incidences of acute radiation esophagitis ≥ grade 2 were significantly lower in the HT group than in the 3D-CRT group (P=0.027). Two-year overall response rate was significantly higher in the HT group than in the 3D-CRT group (P=0.015). One- and 2-year OS rates were significantly higher in the HT group (95.0% and 68.7%, respectively) than in the 3D-CRT group (85.5% and 47.6%, respectively; P=0.0236). One- and 2-year PFS rates were significantly higher in the HT group (57.8% and 26.3%, respectively) than in the 3D-CRT group (32.7% and 11.4%, respectively; P=0.0351). Univariate analysis indicated that performance status (PS), T stage and radiotherapy technique were significant prognostic factors for both OS

Hypofractionation Regimens for Stereotactic Radiotherapy for Large Brain Tumors

International Nuclear Information System (INIS)

Yuan Jiankui; Wang, Jian Z.; Lo, Simon; Grecula, John C.; Ammirati, Mario; Montebello, Joseph F.; Zhang Hualin; Gupta, Nilendu; Yuh, William T.C.; Mayr, Nina A.

2008-01-01

Purpose: To investigate equivalent regimens for hypofractionated stereotactic radiotherapy (HSRT) for brain tumor treatment and to provide dose-escalation guidance to maximize the tumor control within the normal brain tolerance. Methods and Materials: The linear-quadratic model, including the effect of nonuniform dose distributions, was used to evaluate the HSRT regimens. The α/β ratio was estimated using the Gammaknife stereotactic radiosurgery (GKSRS) and whole-brain radiotherapy experience for large brain tumors. The HSRT regimens were derived using two methods: (1) an equivalent tumor control approach, which matches the whole-brain radiotherapy experience for many fractions and merges it with the GKSRS data for few fractions; and (2) a normal-tissue tolerance approach, which takes advantages of the dose conformity and fractionation of HSRT to approach the maximal dose tolerance of the normal brain. Results: A plausible α/β ratio of 12 Gy for brain tumor and a volume parameter n of 0.23 for normal brain were derived from the GKSRS and whole-brain radiotherapy data. The HSRT prescription regimens for the isoeffect of tumor irradiation were calculated. The normal-brain equivalent uniform dose decreased as the number of fractions increased, because of the advantage of fractionation. The regimens for potential dose escalation of HSRT within the limits of normal-brain tolerance were derived. Conclusions: The designed hypofractionated regimens could be used as a preliminary guide for HSRT dose prescription for large brain tumors to mimic the GKSRS experience and for dose escalation trials. Clinical studies are necessary to further tune the model parameters and validate these regimens

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

International Nuclear Information System (INIS)

Graham, P.H.; Bucci, J.; Browne, L.

2010-01-01

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.

Accelerated radiotherapy planners calculated by parallelization with GPUs

International Nuclear Information System (INIS)

Reinado, D.; Cozar, J.; Alonso, S.; Chinillach, N.; Cortina, T.; Ricos, B.; Diez, S.

2011-01-01

In this paper we have developed and tested by a subroutine parallelization architectures graphics processing units (GPUs) to apply to calculations with standard algorithms known code. The experience acquired during these tests shall also apply to the MC calculations in radiotherapy if you have the code.

Experimental radiotherapy and clinical radiobiology. Vol. 20. Proceedings

International Nuclear Information System (INIS)

Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemannn, Hans-Peter; Zips, Daniel

2011-01-01

The proceedings include contributions on the following issues: laser driven proton accelerators on the way for radiotherapy, radiobiological evaluation of new radiations; molecular factors of radiation response; biological targeting; EGFR epidermal growth factor receptor/targeting - combined internal and external irradiation, radiobiology of normal tissues; dose-volume histograms for the radiotherapy: curves without radiobiological relevance or important information for the therapy planning; HPV (human papilloma virus) and radiation sensitivity of HNSCC (head and neck squamous cell carcinomas): evidence, radiobiological mechanism, clinical consequences and perspectives; mechanisms of action and intertumoral heterogeneity of response to EGFR inhibition in radiotherapy of solid tumors; evaluation of biomarkers for radiotherapy.

Customized mold radiotherapy with prosthetic apparatus for oral cancers

International Nuclear Information System (INIS)

Noguchi, Tadahide; Tsuchiya, Yoshiyuki; Hayasaka, Junichi; Itoh, Hiroto; Jinbu, Yoshinori; Kusama, Mikio; Takahashi, Satoru; Nakazawa, Masanori

2014-01-01

Eight patients (6 males, 2 females; median age, 78 years; age range, 31-94 years) were treated by mold radiotherapy with a prosthetic apparatus for oral cancers between October 2006 and March 2013. The primary sites were the tongue in 3 cases, hard palate and buccal mucosa in 2 cases each, and oral floor in 1 case. The type of treatment consisted of radical radiotherapy and palliative radiotherapy in 2 cases each, and preoperative radiotherapy, postoperative radiotherapy, additional radiotherapy after external beam radiotherapy and systemic chemotherapy in 1 case each. Patients received 40-50 Gy in 8-10 fractions with mold radiotherapy. Two patients who received radical radiotherapy showed no signs of recurrence or metastasis. The present therapy contributed to patients' palliative, postoperative, and preoperative therapy. Mold radiotherapy with a prosthetic appliance was performed safely and was a useful treatment for several types of oral cancer. (author)

Probabilistic safety assessment of the radiotherapy treatment with a linear accelerator for medical use

International Nuclear Information System (INIS)

Vilaragut Llanes, Juan Jose; Ferro Fernandez, Ruben; Rodriguez MartI, Manuel; Ramirez, Maria Luisa; Perez Mulas, Arturo; Barrientos Montero, Marta; Ortiz Lopez, Pedro; Somoano, Fernando; Delgado RodrIguez, Jose Miguel; Papadopulos, Susana B.; Pereira Jr, Pedro Paulo; Lopez Morones, Ramon; Larrinaga Cortina, Eduardo; Rivero Oliva, Jose de Jesus; Alemanny, Jorge

2010-01-01

This paper presents the results of the Probabilistic Safety Assessment to the radiotherapy treatment with an Electron Linear Accelerator for Medical Use, which was conducted in the framework of the Iberian-American Forum of Radiological and Nuclear Regulatory Agencies. Potential accidental exposures during the treatment of patients, workers and members of the public were assessed, although the study was mainly focused on patients. The methodology of failure modes and effects analysis was used to define accident initiating events and methods of event tree and fault tree analysis to determine the accident sequences that may occur. After quantifying the frequency of occurrence of the accident sequences, an important analysis was carried out in order to determine the most significant events from the point of view of safety. The major contributors to risk were identified as well as the most appropriate safety recommendations to reduce it. (author)

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

Directory of Open Access Journals (Sweden)

Budach V

2006-01-01

Full Text Available Abstract Background 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. Methods Randomised trials testing curatively intended RT (≥60 Gy in >4 weeks/>50 Gy in Results 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 Conclusion RT combined with simultaneous 5-FU, cisplatin, carboplatin, and mitomycin C as single drug or combinations of 5-FU with one of the other drugs results in a large survival advantage irrespective the employed radiation schedule. If radiation therapy is used as single modality, hyperfractionation leads to a significant improvement of overall survival. Accelerated radiation therapy alone, especially when given as split course radiation schedule or extremely accelerated treatments with decreased total dose, does not increase overall survival.

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

Science.gov (United States)

Harrabi, Semi B; Adeberg, Sebastian; Welzel, Thomas; Rieken, Stefan; Habermehl, Daniel; Debus, Jürgen; Combs, Stephanie E

2014-09-16

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 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.

External Beam Radiotherapy in Metastatic Bone Pain from Solid ...

African Journals Online (AJOL)

Key Words: Bone, metastasis, radiotherapy, pain, control randomized ... described the efficacy of external beam radiotherapy in pain .... life of patients with multiple myeloma. Eur. J. ... Rades D, Jeremic B, Hoskin PJ: The Role of ... randomised multicenter trial on single fraction ... "The subjective experience of acute pain. An.

EORTC 22972-26991/MRC BR10 trial: Fractionated stereotactic boost following conventional radiotherapy of high grade gliomas

International Nuclear Information System (INIS)

Baumert, Brigitta G.; Brada, Michael; Bernier, Jacques; Kortmann, Rolf D.; Dehing-Oberije, Cary; Collette, Laurence; Davis, J. Bernard

2008-01-01

Background and purpose: The EORTC trial No. 22972 investigated the role of an additional fractionated stereotactic boost (fSRT) to conventional radiotherapy for patients with high grade gliomas. A quality-assurance (QA) programme was run in conjunction with the study and was the first within the EORTC addressing the quality of a supposedly highly accurate treatment technique such as stereotactic radiotherapy. A second aim was to investigate a possible relation between the clinical results of the stereotactic boost arm and the results of the QA. Materials and methods: The trial was closed in 2001 due to low accrual. In total, 25 patients were randomized: 14 into the experimental arm and 11 into the control arm. Six centres randomized patients, 8 centres had completed the dummy run (DR) for the stereotactic boost part. All participating centres (9) were asked to complete a quality-assurance questionnaire. The DR consisted of treatment planning according to the guidelines of the protocol on 3 different tumour volumes drawn on CT images of a humanized phantom. The SRT technique to be used was evaluated by the questionnaire. Clinical data from patients recruited to the boost arm from 6 participating centres were analysed. Results: There was a full compliance to the protocol requirements for 5 centres. Major and minor deviations in conformality were observed for 2 and 3 centres, respectively. Of the 8 centres which completed the DR, one centre did not comply with the requirements of stereotactic radiotherapy concerning accuracy, dosimetry and planning. Median follow-up and median overall survival were 39.2 and 21.4 months, respectively. Acute and late toxicities of the stereotactic boost were low. One radiation necrosis was seen for a patient who has not received the SRT boost. Three reported serious adverse events were all seizures and probably therapy-related. Conclusions: Overall compliance was good but not ideal from the point of view of this highly precise radiation

Heavy-ion radiography applied to charged particle radiotherapy

International Nuclear Information System (INIS)

Chen, G.T.Y.; Fabrikant, J.I.; Holley, W.R.; Tobias, C.A.; Castro, J.R.

1980-01-01

The objectives of the heavy-ion radiography research program applied to the clinical cancer research program of charged particle radiotherapy have a twofold purpose: (1) to explore the manner in which heavy-ion radiography and CT reconstruction can provide improved tumor localization, treatment planning, and beam delivery for radiotherapy with accelerated heavy charged particles; and (2) to explore the usefulness of heavy-ion radiography in detecting, localizing, and sizing soft tissue cancers in the human body. The techniques and procedures developed for heavy-ion radiography should prove successful in support of charged particle radiotherapy

Peroperative radiotherapy in the treatment of cancer of the pancreas

International Nuclear Information System (INIS)

Huguier, M.; Schlienger, M.; Houry, S.; Charron, R.

1987-01-01

7 patients presenting with unresected (6 cases) or resected (1 case) cancer of the pancreas were treated peroperatively by radiotherapy. Tumors were treated with 15 to 20 Gy delivered by a particle accelerator. There were no post-operative complications. Three patients who were experiencing pain before radiotherapy no longer had pain after radiotherapy and this effect was maintained. Five patients died during the follow-up period after 5 to 10 months. Two patients are still alive after 4 and 9 months follow-up. This experience with peroperative radiotherapy should be continued [fr

Promising results with image guided intensity modulated radiotherapy for muscle invasive bladder cancer

International Nuclear Information System (INIS)

Whalley, D.; Caine, H.; McCloud, P.; Guo, L.; Kneebone, A.; Eade, T.

2015-01-01

To describe the feasibility of image guided intensity modulated radiotherapy (IG-IMRT) using daily soft tissue matching in the treatment of bladder cancer. Twenty-eight patients with muscle-invasive carcinoma of the bladder were recruited to a protocol of definitive radiation using IMRT with accelerated hypofractionation with simultaneous integrated boost (SIB). Isotropic margins of .5 and 1 cm were used to generate the high risk and intermediate risk planning target volumes respectively. Cone beam CT (CBCT) was acquired daily and a soft tissue match was performed. Cystoscopy was scheduled 6 weeks post treatment. The median age was 83 years (range 58-92). Twenty patients had stage II or III disease, and eight were stage IV. Gross disease received 66 Gy in 30 fractions in 11 patients (ten with concurrent chemotherapy) or 55 Gy in 20 fractions for those of poorer performance status or with palliative intent. All patients completed radiation treatment as planned. Three patients ceased chemotherapy early due to toxicity. Six patients (21 %) had acute Grade ≥ 2 genitourinary (GU) toxicity and six (21 %) had acute Grade ≥ 2 gastrointestinal (GI) toxicity. Five patients (18 %) developed Grade ≥2 late GU toxicity and no ≥2 late GI toxicity was observed. Nineteen patients underwent cystoscopy following radiation, with complete response (CR) in 16 cases (86 %), including all patients treated with chemoradiotherapy. Eight patients relapsed, four of which were local relapses. Of the patients with local recurrence, one underwent salvage cystectomy. For patients treated with definitive intent, freedom from locoregional recurrence (FFLR) and overall survival (OS) was 90 %/100 % for chemoradiotherapy versus 86 %/69 % for radiotherapy alone. IG- IMRT using daily soft tissue matching is a feasible in the treatment of bladder cancer, enabling the delivery of accelerated synchronous integrated boost with good early local control outcomes and low toxicity

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

International Nuclear Information System (INIS)

Kitamura, Masayuki; Kunieda, Etsuo; Kawaguchi, Osamu; Ando, Yutaka; Shigematsu, Naoyuki; Shiba, Toshiyuki; Kubo, Atsushi

2002-01-01

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)

Impact of radiotherapy on myasthenia gravis in patients with malignant thymomas

International Nuclear Information System (INIS)

Hou Xiuyu; Xu Yonggang; Gao Hong; Li Ming; Li Gaofeng; Liu Mingyuan

2006-01-01

Objective: To evaluate the change of myasthenia gravis(MG) during radiotherapy for patients with malignant thymomas. Methods: Forty-five with malignant thymomas patients with were analyzed. The median total dose was DT54.2 Gy in 1.8-2.0 Gy/fraction, 5 clays a week. Anti-cholinesterase, such as pyridostigmine was used to control the MG symptoms. Results: Forty-five patients completed radiotherapy on schedule except one from whom the treatment was was with drawn because of respiratory muscle involvement. Among these 44 patients, myasthenic symptom was relieved in 4 to various degrees, 4 progressed, 34 no change and 2 developed cholinergic crisis. Myasthenic symptom was not changed in one patient for whom radiotherapy had been standed before operation nor during the course of postoperative radiotherapy. Conclusions: A course of radiotherapy of DT54.2 Gy, on fractionation of DT1.8-2.0 Gy modal would not aggravate myasthenia. However, proper use of anti-cholinesterase, careful observation and timely drug-adjustment are necessary. (authors)

Cost-benefit analysis on radiotherapy services for cancer treatment, with LINAC type equipments (linear accelerators

Directory of Open Access Journals (Sweden)

Luiz Alberto Blois

2014-12-01

Full Text Available This work consists in analyzing the economic feasibility of the investment to implement a Radiotherapy sector for radiological of cancer treatment by type linear accelerators equipments, based on the case of a public hospital in São Paulo. From technical and financial details of the project and the survey reference values for health care to their procedures, the statistical outcome of treatment on patients' life expectancy and average income indicators of the state's population, were estimated to income (private and social and expenses of this health service and other elements that make up the flow of the investment project box. From these estimates we evaluated public and private investment return, ie, if it fits only on the public sector or if private sector could also implement this projects geared exclusively to free admittance.

Treatment accuracy of fractionated stereotactic radiotherapy

International Nuclear Information System (INIS)

Kumar, Shaleen; Burke, Kevin; Nalder, Colin; Jarrett, Paula; Mubata, Cephas; A'Hern, Roger; Humphreys, Mandy; Bidmead, Margaret; Brada, Michael

2005-01-01

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

Acoustic neuromas: single dose vs fractionated therapy

International Nuclear Information System (INIS)

Fuss, M.; Debus, J.; Lohr, F.; Engenhart-Cabillic, R.; Wannenmacher, M.

1997-01-01

Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

Stereotactic body radiotherapy for lung cancer: how much does it really cost?

Science.gov (United States)

Lievens, Yolande; Obyn, Caroline; Mertens, Anne-Sophie; Van Halewyck, Dries; Hulstaert, Frank

2015-03-01

Despite the lack of randomized evidence, stereotactic body radiotherapy (SBRT) is being accepted as superior to conventional radiotherapy for patients with T1-2N0 non-small-cell lung cancer in the periphery of the lung and unfit or unwilling to undergo surgery. To introduce SBRT in a system of coverage with evidence development, a correct financing had to be determined. A time-driven activity-based costing model for radiotherapy was developed. Resource cost calculation of all radiotherapy treatments, standard and innovative, was conducted in 10 Belgian radiotherapy centers in the second half of 2012. The average cost of lung SBRT across the 10 centers (6221&OV0556;) is in the range of the average costs of standard fractionated 3D-conformal radiotherapy (5919&OV0556;) and intensity-modulated radiotherapy (7379&OV0556;) for lung cancer. Hypofractionated 3D-conformal radiotherapy and intensity-modulated radiotherapy schemes are less costly (3993&OV0556; respectively 4730&OV0556;). The SBRT cost increases with the number of fractions and is highly dependent of personnel and equipment use. SBRT cost varies more by centre than conventional radiotherapy cost, reflecting different technologies, stages in the learning curve and a lack of clear guidance in this field. Time-driven activity-based costing of radiotherapy is feasible in a multicentre setup, resulting in real-life resource costs that can form the basis for correct reimbursement schemes, supporting an early yet controlled introduction of innovative radiotherapy techniques in clinical practice.

The spanish radiotherapy park: past and present

International Nuclear Information System (INIS)

Tormo Ferrero, Manuel J.

2001-01-01

The present article has as objective to provide a general overview on the spanish radiotherapy park, presenting how was its start and evolution until the current state. Considering only the units of teletherapy and the accelerators. Actually in Spain there is 28 units of Cobalt therapy, in functioning during the last two decades, being advised a rapid substitution to accelerators

TU-H-BRC-07: Therapeutic Benefit in Spatially Fractionated Radiotherapy (GRID) Using Helical Tomotherapy

International Nuclear Information System (INIS)

Narayanasamy, G; Zhang, X; Paudel, N; Morrill, S; Maraboyina, S; Peacock, L; Penagaricano, J; Meigooni, A; Liang, X

2016-01-01

Purpose: The aim of this project is to study the therapeutic ratio (TR) for helical Tomotherapy (HT) based spatially fractionated radiotherapy (GRID). Estimation of TR was based on the linear-quadratic cell survival model by comparing the normal cell survival in a HT GRID to that of a uniform dose delivery in an open-field for the same tumor survival. Methods: HT GRID plan was generated using a patient specific virtual GRID block pattern of non-divergent, cylinder shaped holes using MLCs. TR was defined as the ratio of normal tissue surviving fraction (SF) under HT GRID irradiation to an open field irradiation with an equivalent dose that result in the same tumor cell SF. The ratio was estimated from DVH data on ten patient plans with deep seated, bulky tumor approved by the treating radiation oncologist. Dependence of the TR values on radio-sensitivity of the tumor cells and prescription dose were also analyzed. Results: The mean ± standard deviation (SD) of TR was 4.0±0.7 (range: 3.1 to 5.5) for the 10 patients with single fraction dose of 20 Gy and tumor cell SF of 0.5 at 2 Gy. In addition, mean±SD of TR = 1±0.1 and 18.0±5.1 were found for tumor with SF of 0.3 and 0.7, respectively. Reducing the prescription dose to 15 and 10 Gy lowered the TR to 2.0±0.2 and 1.2±0.04 for a tumor cell SF of 0.5 at 2 Gy. In this study, the SF of normal cells was assumed to be 0.5 at 2 Gy. Conclusion: HT GRID displayed a significant therapeutic advantage over uniform dose from an open field irradiation. TR increases with the radioresistance of the tumor cells and with prescription dose.

Fractionated radiosurgery for painful spinal metastases: DOSIS - a phase II trial

International Nuclear Information System (INIS)

Guckenberger, Matthias; Hawkins, Maria; Flentje, Michael; Sweeney, Reinhart A

2012-01-01

One third of all cancer patients will develop bone metastases and the vertebral column is involved in approximately 70% of these patients. Conventional radiotherapy with of 1–10 fractions and total doses of 8-30 Gy is the current standard for painful vertebral metastases; however, the median pain response is short with 3–6 months and local tumor control is limited with these rather low irradiation doses. Recent advances in radiotherapy technology – intensity modulated radiotherapy for generation of highly conformal dose distributions and image-guidance for precise treatment delivery – have made dose-escalated radiosurgery of spinal metastases possible and early results of pain and local tumor control are promising. The current study will investigate efficacy and safety of radiosurgery for painful vertebral metastases and three characteristics will distinguish this study. 1) A prognostic score for overall survival will be used for selection of patients with longer life expectancy to allow for analysis of long-term efficacy and safety. 2) Fractionated radiosurgery will be performed with the number of treatment fractions adjusted to either good (10 fractions) or intermediate (5 fractions) life expectancy. Fractionation will allow inclusion of tumors immediately abutting the spinal cord due to higher biological effective doses at the tumor - spinal cord interface compared to single fraction treatment. 3) Dose intensification will be performed in the involved parts of the vertebrae only, while uninvolved parts are treated with conventional doses using the simultaneous integrated boost concept. It is the study hypothesis that hypo-fractionated image-guided radiosurgery significantly improves pain relief compared to historic data of conventionally fractionated radiotherapy. Primary endpoint is pain response 3 months after radiosurgery, which is defined as pain reduction of ≥ 2 points at the treated vertebral site on the 0 to 10 Visual Analogue Scale. 60 patients