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Sample records for beam radiotherapy ebrt

  1. The Degree of Lipiodol Accumulation Can Be an Indicator of Successful Treatment for Unresectable Hepatocellular Carcinoma (HCC) Patients - in the Case of Transcatheter Arterial Chemoembolization (TACE) and External Beam Radiotherapy (EBRT)

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    Yang, Ping; Zeng, Zhao-Chong; Wang, Bin-Liang; Zhang, Jian-Ying; Fan, Jia; Zhou, Jian; Hu, Yong

    2016-01-01

    Purpose: Transcatheter arterial chemoembolization (TACE) in combination with external beam radiotherapy (EBRT) results in improved survival due to better local control in patients with unresectable hepatocellular carcinoma (HCC). The purpose of this study was to investigate lipiodol accumulation, as it reflects tumor burden and is a potential prognostic factor, in HCC patients treated with TACE/EBRT. Methods and Materials: We retrospectively studied 147 patients with unresectable HCC treated with TACE and EBRT. Clinical features, adverse reactions, and prognostic factors were analyzed. All patients were treated with TACE 1-6 times in combination with EBRT (44-66 Gy) in dose of 2 Gy/fraction given once a day five times a week. Tumor status and laboratory findings were followed. The degree of lipiodol accumulation was assessed by computed tomography before EBRT, and was categorized as either complete/intense or low/moderate. Results: The response rate of tumor size after EBRT was 68.2%, median survival was 23.1 months, and overall survival rates were 86.6%, 49.2%, and 28.2% at 1, 2, and 3 years, respectively. Univariate analysis showed that lower hemoglobin levels, higher alkaline phosphatase levels, Child-Pugh B, negative alpha-fetoprotein (AFP) response after EBRT, poor treatment response after EBRT, tumor diameter >10 cm, and poor lipiodol accumulation were unfavorable prognostic factors. On multivariate analysis, higher hemoglobin levels, Child-Pugh A, decreased AFP levels after treatment, Helical Tomotherapy (HT) and intense lipiodol accumulation after TACE were significant favorable predictors. Conclusions: The degree of lipiodol accumulation before EBRT is a prognostic factor in patients with unresectable HCC. Increased AFP levels after EBRT are always associated with poor survival. HT is recommended as a potentially better EBRT modality than three-dimensional conformal radiation therapy (3D-CRT). PMID:27471557

  2. Combination of External Beam Radiotherapy (EBRT) With Intratumoral Injection of Dendritic Cells as Neo-Adjuvant Treatment of High-Risk Soft Tissue Sarcoma Patients

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    Finkelstein, Steven E., E-mail: steven.finkelstein@moffitt.org [H. Lee Moffitt Cancer Center, Tampa, FL (United States); Iclozan, Cristina; Bui, Marilyn M.; Cotter, Matthew J.; Ramakrishnan, Rupal; Ahmed, Jamil; Noyes, David R.; Cheong, David; Gonzalez, Ricardo J.; Heysek, Randy V.; Berman, Claudia; Lenox, Brianna C.; Janssen, William; Zager, Jonathan S.; Sondak, Vernon K.; Letson, G. Douglas; Antonia, Scott J. [H. Lee Moffitt Cancer Center, Tampa, FL (United States); Gabrilovich, Dmitry I., E-mail: dmitry.gabrilovich@moffitt.org [H. Lee Moffitt Cancer Center, Tampa, FL (United States)

    2012-02-01

    Purpose: The goal of this study was to determine the effect of combination of intratumoral administration of dendritic cells (DC) and fractionated external beam radiation (EBRT) on tumor-specific immune responses in patients with soft-tissue sarcoma (STS). Methods and Material: Seventeen patients with large (>5 cm) high-grade STS were enrolled in the study. They were treated in the neoadjuvant setting with 5,040 cGy of EBRT, split into 28 fractions and delivered 5 days per week, combined with intratumoral injection of 10{sup 7} DCs followed by complete resection. DCs were injected on the second, third, and fourth Friday of the treatment cycle. Clinical evaluation and immunological assessments were performed. Results: The treatment was well tolerated. No patient had tumor-specific immune responses before combined EBRT/DC therapy; 9 patients (52.9%) developed tumor-specific immune responses, which lasted from 11 to 42 weeks. Twelve of 17 patients (70.6%) were progression free after 1 year. Treatment caused a dramatic accumulation of T cells in the tumor. The presence of CD4{sup +} T cells in the tumor positively correlated with tumor-specific immune responses that developed following combined therapy. Accumulation of myeloid-derived suppressor cells but not regulatory T cells negatively correlated with the development of tumor-specific immune responses. Experiments with {sup 111}In labeled DCs demonstrated that these antigen presenting cells need at least 48 h to start migrating from tumor site. Conclusions: Combination of intratumoral DC administration with EBRT was safe and resulted in induction of antitumor immune responses. This suggests that this therapy is promising and needs further testing in clinical trials design to assess clinical efficacy.

  3. Prostate-specific antigen kinetics following hypofractionated stereotactic body radiotherapy boost as post-external beam radiotherapy versus conventionally fractionated external beam radiotherapy for localized prostate cancer

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    Phak, Jeong Hoon; Kim, Hun Jung; Kim, Woo Chul

    2015-01-01

    Background Stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for localized prostate cancer. The purpose of this study was to compare the prostate-specific antigen (PSA) kinetics between conventionally fractionated external beam radiotherapy (CF-EBRT) and SBRT boost after whole pelvis EBRT (WP-EBRT) in localized prostate cancer. Methods A total of 77 patients with localized prostate cancer [T-stage, T1–T3; Gleason score (GS) 5–9; PSA 

  4. A prospective randomized trial: a comparison of the analgesic effect and toxicity of 153Sm radioisotope treatment in monotherapy and combined therapy including local external beam radiotherapy (EBRT) among metastatic castrate resistance prostate cancer (mCRPC) patients with painful bone metastases.

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    Baczyk, M; Milecki, P; Pisarek, M; Gut, P; Antczak, A; Hrab, M

    2013-01-01

    Bone metastases in prostate cancer constitute the most frequent cause of systemic failure in treatment, which results in numerous complications and finally leads to patient's death. Pain is one of the first and most important clinical symptoms of bone metastases and can be found among more than 80% of patients. Therefore, the most analgetic effective and simultaneously the least toxic treatment is an important point of therapeutic management in this group of patients. The aim of this prospective clinical trial was a comparison of analgetic effectiveness and toxicity of monotherapy with 153Sm isotope to combined therapy (153Sm + EBRT) among patients diagnosed with multiple painful bone metastases due to CRPC (mCRPC). 177 patients with mCRPC were included into the prospective randomised clinical trial in which 89 patients were assigned to the 153Sm isotope monotherapy, while 88 patients were assigned to the combined therapy including 153Sm isotope therapy and EBRT. All patients were diagnosed (bone scan and X-ray or/and CT or/and MRI) with painful bone metastases (bone pain intensity >= 6 according to VAS classification). The following additional inclusion criteria were established: histologically confirmed adenocarcinoma of prostate, multifocal bone metastases, no prior chemotherapy or palliative radiotherapy to bone. All patients signed informed consent.The combination of the isotope therapy with EBRT was more effective analgetic treatment than isotope therapy alone. The highest pain decline was noticed in the first weeks after treatment termination. In the whole group, a total or partial analgesic effect was observed among 154 (87%) patients while among 23 (13%) patients there was a lack of analgesic effect or even pain intensification. The results of this clinical trial demonstrated that for patients with multiple mCRPC it is recommended to combine the 153Sm isotope therapy with local EBRT because of a greater analgetic effect. It is important to note that

  5. Radical radiotherapy treatment (EBRT + HDR-ICRT of carcinoma of the uterine cervix: Outcome in patients treated at a rural center in India

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    Jain Vandana

    2007-01-01

    Full Text Available Aim: To report the outcome of carcinoma of the uterine cervix patients treated radically by external beam radiotherapy (EBRT and high-dose-rate (HDR intracavitary radiotherapy (ICRT. Materials and Methods: Between January 1997 to December 2001, a total of 550 newly diagnosed cases of carcinoma of the uterine cervix were reported in the department. All cases were staged according to the International Federation of Gynecologists and Oncologists (FIGO staging system, but for analytical convenience, the staging was limited to stages I, II, III, and IV. Out of the 550 cases, 214 completed radical radiotherapy (EBRT + HDR-ICRT and were retrospectively analyzed for presence of local residual disease, local recurrence, distant metastases, radiation reactions, and disease-free survival. Results: There were 7 (3.27%, 88 (41.1%, 101 (47.1%, and 18 (8.4% patients in stage I, II, III, and IV, respectively. The median follow-up time for all patients was 43 months (range: 3-93 months and for patients who were disease free till the last follow-up it was 59 months (range: 24-93 months. The overall treatment time (OTT ranged from 52 to 73 days (median 61 days. The 5-year disease-free mean survival rate was 58%, 44%, 33%, and 15%, with 95% confidence interval of 48 to 68, 37 to 51, 24 to 35, and 6 to 24 for stages I, II, III, and IV, respectively. There were 62 (28.97% cases with local residual disease, 35 (16.3% developed local recurrence/distant metastases, 17 (7.9% developed distant metastases, and 9 (4.2% had local recurrence as well. Discussion and Conclusion: The overall outcome was poor in advanced stage disease, but might be improved by increasing the total dose, decreasing overall duration of treatment, and by adding chemotherapy in patients with disease limited to the pelvis.

  6. Hypofractionated SBRT versus conventionally fractionated EBRT for prostate cancer: comparison of PSA slope and nadir

    OpenAIRE

    Anwar, Mekhail; Weinberg, Vivian; Albert J. Chang; Hsu, I-Chow; Roach, Mack; Gottschalk, Alexander

    2014-01-01

    Background Patients with early stage prostate cancer have a variety of curative radiotherapy options, including conventionally-fractionated external beam radiotherapy (CF-EBRT) and hypofractionated stereotactic body radiotherapy (SBRT). Although results of CF-EBRT are well known, the use of SBRT for prostate cancer is a more recent development, and long-term follow-up is not yet available. However, rapid post-treatment PSA decline and low PSA nadir have been linked to improved clinical outcom...

  7. In vivo dosimetry in external beam radiotherapy

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    Mijnheer, Ben [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam 1066 CX (Netherlands); Beddar, Sam [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Izewska, Joanna [Division of Human Health, International Atomic Energy Agency, Vienna 1400 (Austria); Reft, Chester [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois 60637 (United States)

    2013-07-15

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  8. Localized External Beam Radiation Therapy (EBRT) to the Pelvis Induces Systemic IL-1Beta and TNF-Alpha Production: Role of the TNF-Alpha Signaling in EBRT-Induced Fatigue.

    Science.gov (United States)

    McDonald, Tasha L; Hung, Arthur Y; Thomas, Charles R; Wood, Lisa J

    2016-01-01

    Prostate cancer patients undergoing localized external beam radiation therapy (EBRT) can experience a progressive increase in fatigue, which can affect physical functioning and quality of life. The purpose of this study was to develop a mouse EBRT prostate cancer treatment model with which to determine the role of pro-inflammatory cytokines in the genesis of EBRT-related fatigue. We assessed voluntary wheel-running activity (VWRA) as a proxy for fatigue, food intake and body weight in male C57BL/6 mice undergoing EBRT to the pelvis. In the first experiment, anesthetized male C57BL/6 mice underwent fractionated EBRT to the pelvis for a total dose of 68.2 Gy, thereby mimicking a clinically relevant therapeutic dose and frequency. The day after the last treatment, levels of IL-1β and TNF-α in plasma along with mRNA levels in liver, colon and whole brain were measured. EBRT-induced fatigue resulted in reduced body weight, diminished food intake, and increased plasma and tissue levels of IL-1β and TNF-α. In a follow-up experiment, we used TNF-α-deficient mice to further delineate the role of TNF-α signaling in EBRT-induced sickness behavior. EBRT-induced changes in fatigue, food intake and body weight were no different between TNF-α deficient mice and their wild-type counterparts. Taken together our data demonstrate that a clinically relevant localized irradiation of the pelvis induces a systemic IL-1β and TNF-α response and sickness behavior in mice, but the TNF-α signaling pathway alone does not independently mediate these effects.

  9. Evaluation of the Curative Effect of External Beam Radiotherapy and Brachytherapy for Tongue Carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ping Wang; Qingsong Pang

    2007-01-01

    OBJECTIVE To evaluate the curative effect of external beam radiotherapy (EBRT) and brachytherapy (BT) for tongue carcinoma. METHODS From 1991 to 2003, 35 patients received EBRT and BT in our department. We analyzed their curative and side effects retrospectively. RESULTS Local control was 80%. The 3-year overall (OS) and disease specific survival (DSS) rates were 75% and 79%. One patient developed metastases. Three patients (9%) developed different late complications. CONCLUSIONS Local regional control, survival, and complications in patients with tongue carcinoma treated by EBRT and BT have been satisfactory.

  10. Radical prostatectomy versus external beam radiotherapy for localized prostate cancer. Comparison of treatment outcomes

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    Kim, Yeon-Joo; Cho, Kwan Ho; Lee, Kang Hyun; Moon, Sung Ho; Kim, Tae Hyun; Shin, Kyung Hwan; Kim, Joo-Young; Kim, Young-kyung; Lee, Se Byeong [National Cancer Center, Research Institute and Hospital, Goyang (Korea, Republic of); Pyo, Hong Ryull [Sungkyunkwan University, Department of Radiation Oncology, Samsung Medical Center, School of Medicine, Seoul (Korea, Republic of)

    2015-04-01

    We retrospectively compared the treatment outcomes of localized prostate cancer between radical prostatectomy (RP) and external beam radiotherapy (EBRT). We retrospectively analyzed 738 patients with localized prostate cancer who underwent either RP (n = 549) or EBRT (n = 189) with curative intent at our institution between March 2001 and December 2011. Biochemical failure was defined as a prostate-specific antigen (PSA) level of ≥ 0.2 ng/ml in the RP group and the nadir of + ≥ 2 ng/ml in the EBRT group. The median (range) follow-up duration was 48.8 months (0.7-133.2 months) and 48.7 months (1.0-134.8 months) and the median age was 66 years (45-89 years) and 71 years (51-84 years; p < 0.001) in the RP and EBRT groups, respectively. Overall, 21, 42, and 36 % of patients in the RP group, and 15, 27, and 58 % of patients in the EBRT group were classified as low, intermediate, and high risk, respectively (p < 0.001). Androgen-deprivation therapy was more common in the EBRT group (59 vs. 27 %, respectively; p < 0.001). The 8-year biochemical failure-free survival rates were 44 and 72 % (p < 0.001) and the disease-specific survival rates were 98 % and 97 % (p = 0.543) in the RP and EBRT groups, respectively. Although the EBRT group included more high-risk patients than did the RP group, the outcomes of EBRT were not inferior to those of RP. Our data suggest that EBRT is a viable alternative to RP for treating localized prostate cancer. (orig.) [German] Wir vergleichen retrospektiv die Verfahrensergebnisse des lokal begrenzten Prostatakarzinoms zwischen radikaler Prostatektomie (RP) und externer Strahlentherapie (EBRT). Wir analysieren zurueckblickend 738 Patienten mit lokal begrenztem Prostatakarzinom, die zwischen Maerz 2001 und Dezember 2011 in unserem Institut entweder eine RP (n = 549) oder eine EBRT (n = 189) mit kurativer Intention durchliefen. Biochemischer Fehler wurde als prostataspezifisches Antigen (PSA) ≥ 0,2 ng/ml in der RP-Gruppe und ein Nadir +

  11. Unified registration framework for cumulative dose assessment in cervical cancer across external beam radiotherapy and brachytherapy

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    Roy, Sharmili; Totman, John J.; Choo, Bok A.

    2016-03-01

    Dose accumulation across External Beam Radiotherapy (EBRT) and Brachytherapy (BT) treatment fractions in cervical cancer is extremely challenging due to structural dissimilarities and large inter-fractional anatomic deformations between the EBRT and BT images. The brachytherapy applicator and the bladder balloon, present only in the BT images, introduce missing structural correspondences for the underlying registration problem. Complex anatomical deformations caused by the applicator and the balloon, different rectum and bladder filling and tumor shrinkage compound the registration difficulties. Conventional free-form registration methods struggle to handle such topological differences. In this paper, we propose a registration pipeline that first transforms the original images to their distance maps based on segmentations of critical organs and then performs non-linear registration of the distance maps. The resulting dense deformation field is then used to transform the original anatomical image. The registration accuracy is evaluated on 27 image pairs from stage 2B-4A cervical cancer patients. The algorithm reaches a Hausdorff distance of close to 0:5 mm for the uterus, 2:2 mm for the bladder and 1:7 mm for the rectum when applied to (EBRT,BT) pairs, taken at time points more than three months apart. This generalized model-free framework can be used to register any combination of EBRT and BT images as opposed to methods in the literature that are tuned for either only (BT,BT) pair, or only (EBRT,EBRT) pair or only (BT,EBRT) pair. A unified framework for 3D dose accumulation across multiple EBRT and BT fractions is proposed to facilitate adaptive personalized radiation therapy.

  12. Erectile function following brachytherapy, external beam radiotherapy, or radical prostatectomy in prostate cancer patients

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    Putora, P.M.; Buchauer, K.; Plasswilm, L. [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland); Engeler, D.; Schmid, H.P. [Kantonsspital St. Gallen, Department of Urology, St. Gallen (Switzerland); Haile, S.R.; Graf, N. [Kantonsspital St. Gallen, Clinical Trials Unit, St. Gallen (Switzerland)

    2016-03-15

    For localized prostate cancer, treatment options include external beam radiotherapy (EBRT), radical prostatectomy (RP), and brachytherapy (BT). Erectile dysfunction (ED) is a common side-effect. Our aim was to evaluate penile erectile function (EF) before and after BT, EBRT, or RP using a validated self-administered quality-of-life survey from a prospective registry. Analysis included 478 patients undergoing RP (n = 252), EBRT (n = 91), and BT (n = 135) with at least 1 year of follow-up and EF documented using IIEF-5 scores at baseline, 6 weeks, 6 months, 1 year, and annually thereafter. Differences among treatments were most pronounced among patients with no or mild initial ED (IIEF-5 ≥ 17). Overall, corrected for baseline EF and age, BT was associated with higher IIEF-5 scores than RP (+ 7.8 IIEF-5 score) or EBRT (+ 3.1 IIEF-5 score). EBRT was associated with better IIEF-5 scores than RP (+ 4.7 IIEF-5 score). In patients undergoing EBRT or RP with bilateral nerve sparing (NS), recovery of EF was observed and during follow-up, the differences to BT were not statistically significant. Overall age had a negative impact on EF preservation (corrected for baseline IIEF). In our series, EF was adversely affected by each treatment modality. Considered overall, BT provided the best EF preservation in comparison to EBRT or RP. (orig.) [German] Die externe Radiotherapie (EBRT), die radikale Prostatektomie (RP) sowie die Brachytherapie (BT) stellen Behandlungsoptionen fuer das lokalisierte Prostatakarzinom dar. Die erektile Dysfunktion (ED) ist eine haeufige Nebenwirkung dieser Therapien. Unser Ziel war es, die penile erektile Funktion (EF) vor und nach BT, EBRT und RP mit Hilfe eines validierten, vom Patienten ausgefuellten Lebensqualitaetsfragebogens aus einer prospektiven Datenbank zu beurteilen. Mit einer minimalen Nachbeobachtungszeit von einem Jahr wurden 478 Patienten analysiert, die eine RP (n = 252), EBRT (n = 91) oder BT (n = 135) erhalten hatten und deren EF mit

  13. Planning of External Beam Radiotherapy for Prostate Cancer Guided by PET/CT.

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    von Eyben, Finn Edler; Kairemo, Kalevi; Kiljunen, Timo; Joensuu, Timo

    2015-01-01

    In this paper, we give an overview of articles on non-choline tracers for PET/CT for patients with prostate cancer and planning of radiotherapy guided by PET/CT. Nineteen articles described (11)C-Acetate PET/CT. Of 629 patients 483 (77%, 95% CI 74% - 80%) had positive (11)C-Acetate PET/CT scans. Five articles described (18)F-FACBC PET/CT. Of 174 patients, 127 (73%, 95% CI 68% - 78%) had positive scans. Both tracers detected local lesions, lesions in regional lymph nodes, and distant organs. Ten articles described (18)F-NaF PET/CT and found that 1289 of 3918 patients (33%) had positive reactive lesions in bones. PET/CT scan can guide external beam radiotherapy (EBRT) planning for patients with loco-regional prostate cancer. In six studies with 178 patients with localized prostate cancer, PET/CT pointed out dominant intraprostatic lesions (DIL). Oncologists gave EBRT to the whole prostate and a simultaneously integrated boost to the DIL. Four studies with 254 patients described planning of EBRT for patients with PETpositive lymph nodes. After the EBRT, 15 of 29 node-positive patients remained in remission for median 28 months (range 14 to 50 months). Most articles describe (11)C- and (18)F-Choline PET/CT. However, (11)C-Acetate and (18)F-FACBC may also be useful tracers for PET/CT. Planning of radiotherapy guided by MRI or PET/CT is an investigational method for localized prostate cancer. Current clinical controlled trials evaluate whether the method improves overall survival.

  14. External Beam Radiation Therapy (EBRT) for Patients with Malignant Pheochromocytoma and Non-Head and Neck Paraganglioma: Combination with 131I-MIBG

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    Fishbein, Lauren; Bonner, Lara; Torigian, Drew A.; Nathanson, Katherine L.; Cohen, Debbie L.; Pryma, Daniel; Cengel, Keith

    2015-01-01

    In patients with malignant pheochromocytoma and paraganglioma, 131I-MIBG radiotherapy can achieve an objective response rate of 30–50% with the dose limiting toxicity being hematologic. Patients with disseminated disease, who also have a few index bulky or symptomatic lesions, may benefit from the addition of targeted external beam radiotherapy alone or in combination with systemic 131I-MIBG. The records of patients with malignant paraganglioma who were treated with external beam radiotherapy at the University of Pennsylvania from February 1973 to February 2011 were reviewed in an institutional review board approved retrospective study. Of the 17 patients with tumors in the thorax, abdomen, or pelvis, 76% had local control or clinically significant symptomatic relief for at least one year or until death. As expected, the predominant toxicity was due to irradiation of tumor-adjacent normal tissues without clinically significant hematologic toxicity. Due to widespread systemic metastases with areas of bulky, symptomatic tumor, five of the 17 patients were treated with sequential 131I-MIBG (2 mCi/kg per treatment) and external beam radiotherapy to nine sites. In these patients, all areas that were irradiated with external beam radiotherapy showed durable objective response despite all patients eventually experiencing out-of-field systemic progression requiring other treatment. Four of these patients remain alive with excellent performance status 16, 18, 23, and 24 months after external beam radiotherapy. External beam radiotherapy can be highly effective in local management of malignant paraganglioma and can be used in conjunction with 131I-MIBG due to non-overlapping toxicities with excellent control of locally bulky tumors. PMID:22566196

  15. 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....

  16. Successful treatment of a 67-year-old woman with urethral adenocarcinoma with the use of external beam radiotherapy and image guided adaptive interstitial brachytherapy

    DEFF Research Database (Denmark)

    Mujkanovic, Jasmin; Tanderup, Kari; Agerbæk, Mads

    2016-01-01

    Primary urethral cancer (PUC) is a very rare disease. This case report illustrates a successful treatment approach of a 67-year-old woman with a urethral adenocarcinoma selected for an organ preserving treatment with external beam radiotherapy (EBRT) and interstitial brachytherapy (BT) boost, using...... the GEC-ESTRO target concept originally designed for locally advanced cervical cancer (LACC). Treatment included EBRT with 45 Gy in 25 fractions followed by image guided adaptive interstitial BT (IGABT) with a pulsed-dose-rate (PDR) BT boost with 30 Gy in 50 hourly pulses. The D90 for CTVHR was 79.1 Gy...

  17. Safety and Efficacy of Thoracic External Beam Radiotherapy After Airway Stenting in Malignant Airway Obstruction

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    Rochet, Nathalie, E-mail: nrochet@partners.org [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Hauswald, Henrik; Schmaus, Martina; Hensley, Frank [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Huber, Peter [Department of Radiotherapy, German Cancer Research Center, Heidelberg (Germany); Eberhardt, Ralf; Herth, Felix J. [Department of Pulmonology and Respiratory Care Medicine, Thoraxklinik at University of Heidelberg, Heidelberg (Germany); Debus, Juergen; Neuhof, Dirk [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany)

    2012-05-01

    Purpose: We retrospectively evaluated the outcome and toxicity of external beam radiotherapy (EBRT) after airway stents were placed in patients treated for malignant airway obstruction. Methods and Materials: Between 2004 and 2009, we performed airway stenting followed by EBRT in 43 patients for symptomatic primary lung cancer (n = 31) or other thoracic malignancies (n = 12). The median time interval between stent placement and first irradiation was 14 days. A median total dose of 50 Gy was delivered. Sixty-seven percent of the patients had reduced performance status (Karnofsky performance score, {<=}70). Results: EBRT had to be stopped prematurely in 16 patients (37%), at a median total dose of 17 Gy, for various reasons. In this group of patients, the survival was poor, with a median overall survival (OS) of only 21 days. Twenty-seven patients (63%) completed radiotherapy as planned, with a median OS of 8.4 months. Fourteen of 43 patients (33%) developed at least one Common Terminology Criteria for Adverse Event of grade 3 to 5. The most common event was a malignant restenosis of the stent leading to asphyxia (n = 7), followed by fistula formation (n = 4), necrosis (n = 3), mediastinitis with abscess (n = 1), secondary nonmalignant airway stenosis (n = 1), and hemoptysis (n = 1). With the exception of one event, all events were associated with a local progression of the tumor. Conclusions: Although the long-term prognosis for patients with malignant airway obstruction is poor, airway stenting combined with EBRT offers a possible therapeutic option, achieving fast relief of acute respiratory distress with an associated antitumor effect, resulting in a potential survival benefit. However, due to local advanced tumor growth, increased rates of adverse events are to be expected, necessitating careful monitoring.

  18. Palliative external-beam radiotherapy for bone metastases from hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Shinya; Hayashi; Hidekazu; Tanaka; Hiroaki; Hoshi

    2014-01-01

    The incidence of bone metastases(BMs)from hepatocellular carcinoma(HCC)is relatively low compared to those of other cancers,but it has increased recently,especially in Asian countries.Typically,BMs from HCC appear radiologically as osteolytic,destructive,and expansive components with large,bulky soft-tissue masses.These soft-tissue masses are unique to bone metastases from HCC and often replace the normal bone matrix and exhibit expansive growth.They often compress the peripheral nerves,spinal cord,or cranial nerves,causing not only bone pain but also neuropathic pain and neurological symptoms.In patients with spinal BMs,the consequent metastatic spinal cord compression(MSCC)causes paralysis.Skull base metastases(SBMs)with cranial nerve involvement can cause neurological symptoms.Therefore,patients with bony lesions often suffer from pain or neurological symptoms that have a severe,adverse effect on the quality of life.External-beam radiotherapy(EBRT)can effectively relieve bone pain and neurological symptoms caused by BMs.However,EBRT is not yet widely used for the palliative management of BMs from HCC because of the limited number of relevant studies.Furthermore,the optimal dosing schedule remains unclear,despite clinical evidence to support single-fraction ra-diation schedules for primary cancers.In this review,we outline data describing palliative EBRT for BMs from HCC in the context of(1)bone pain;(2)MSCC;and(3)SBMs.

  19. Diagnosis of Post-Radiotherapy Local Failures in Nasopharyngeal Carcinoma: A Prospective Institutional Study

    OpenAIRE

    2014-01-01

    Background This prospective study was conducted to evaluate and compare the efficacies of nasopharyngoscopy and CT scan in the diagnosis of local failure of external beam radiotherapy (EBRT) for nasopharyngeal carcinoma. Methods Total 52 patients of histopathologically proven nasopharyngeal carcinoma treated with external beam radiotherapy (EBRT), were included in this study. For every patient computed tomography (CT), nasopharyngoscopy and nasopharyngeal biopsies were performed 3 months afte...

  20. NOTE Thyroid volume measurement in external beam radiotherapy patients using CT imaging: correlation with clinical and anthropometric characteristics

    Science.gov (United States)

    Veres, C.; Garsi, J. P.; Rubino, C.; Pouzoulet, F.; Bidault, F.; Chavaudra, J.; Bridier, A.; Ricard, M.; Ferreira, I.; Lefkopoulos, D.; de Vathaire, F.; Diallo, I.

    2010-11-01

    The aim of this study is to define criteria for accurate representation of the thyroid in human models used to represent external beam radiotherapy (EBRT) patients and evaluate the relationship between the volume of this organ and clinical and anthropometric characteristics. From CT images, we segmented the thyroid gland and calculated its volume for a population of 188 EBRT patients of both sexes, with ages ranging from 1 to 89 years. To evaluate uncertainties linked to measured volumes, experimental studies on the Livermore anthropomorphic phantom were performed. For our population of EBRT patients, we observed that in children, thyroid volume increased rapidly with age, from about 3 cm3 at 2 years to about 16 cm3 at 20. In adults, the mean thyroid gland volume was 23.5 ± 9 cm3 for males and 17.5 ± 8 cm3 for females. According to anthropometric parameters, the best fit for children was obtained by modeling the log of thyroid volume as a linear function of body surface area (BSA) (p < 0.0001) and age (p = 0.04) and for adults, as a linear function of BSA (p < 0.0001) and gender (p = 0.01). This work enabled us to demonstrate that BSA was the best indicator of thyroid volume for both males and females. These results should be taken into account when modeling the volume of the thyroid in human models used to represent EBRT patients for dosimetry in retrospective studies of the relationship between the estimated dose to the thyroid and long-term follow-up data on EBRT patients.

  1. Thyroid volume measurement in external beam radiotherapy patients using CT imaging: correlation with clinical and anthropometric characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Veres, C; Garsi, J P; Rubino, C; De Vathaire, F; Diallo, I [Inserm, CESP Centre for research in Epidemiology and Population Health, U1018, Radiation Epidemiology Team, F 94807, Villejuif (France); Pouzoulet, F; Bidault, F; Chavaudra, J; Bridier, A; Ricard, M; Ferreira, I; Lefkopoulos, D, E-mail: ibrahim.diallo@igr.f [Institut Gustave Roussy, F-94805, Villejuif (France)

    2010-11-07

    The aim of this study is to define criteria for accurate representation of the thyroid in human models used to represent external beam radiotherapy (EBRT) patients and evaluate the relationship between the volume of this organ and clinical and anthropometric characteristics. From CT images, we segmented the thyroid gland and calculated its volume for a population of 188 EBRT patients of both sexes, with ages ranging from 1 to 89 years. To evaluate uncertainties linked to measured volumes, experimental studies on the Livermore anthropomorphic phantom were performed. For our population of EBRT patients, we observed that in children, thyroid volume increased rapidly with age, from about 3 cm{sup 3} at 2 years to about 16 cm{sup 3} at 20. In adults, the mean thyroid gland volume was 23.5 {+-} 9 cm{sup 3} for males and 17.5 {+-} 8 cm{sup 3} for females. According to anthropometric parameters, the best fit for children was obtained by modeling the log of thyroid volume as a linear function of body surface area (BSA) (p < 0.0001) and age (p = 0.04) and for adults, as a linear function of BSA (p < 0.0001) and gender (p = 0.01). This work enabled us to demonstrate that BSA was the best indicator of thyroid volume for both males and females. These results should be taken into account when modeling the volume of the thyroid in human models used to represent EBRT patients for dosimetry in retrospective studies of the relationship between the estimated dose to the thyroid and long-term follow-up data on EBRT patients. (note)

  2. Particle radiotherapy with carbon ion beams.

    Science.gov (United States)

    Ohno, Tatsuya

    2013-03-04

    Carbon ion radiotherapy offers superior dose conformity in the treatment of deep-seated malignant tumours compared with conventional X-ray therapy. In addition, carbon ion beams have a higher relative biological effectiveness compared with protons or X-ray beams. The algorithm of treatment planning and beam delivery system is tailored to the individual parameters of the patient. The present article reviews the available literatures for various disease sites including the head and neck, skull base, lung, liver, prostate, bone and soft tissues and pelvic recurrence of rectal cancer as well as physical and biological properties.

  3. Hypofractionated Proton Boost Combined with External Beam Radiotherapy for Treatment of Localized Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Silvia Johansson

    2012-01-01

    Full Text Available Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT. The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU and gastrointestinal (GI toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity.

  4. Variation in Use of Androgen Suppression With External-Beam Radiotherapy for Nonmetastatic Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Swisher-McClure, Samuel, E-mail: Swisher-Mcclure@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Pollack, Craig E. [Division of General Internal Medicine, Johns Hopkins University School of Medicine and Johns Hopkins Bloomberg School of Public Health, Baltimore, MD (United States); Christodouleas, John P. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Guzzo, Thomas J. [Department of Surgery, Division of Urology, University of Pennsylvania, Philadelphia, PA (United States); Haas, Naomi B. [Department of Medicine, Division of Hematology and Oncology, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Vapiwala, Neha [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Bekelman, Justin E. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA (United States)

    2012-05-01

    Purpose: To describe practice patterns associated with androgen suppression (AS) stratified by disease risk group in patients undergoing external-beam radiotherapy (EBRT) for localized prostate cancer. Methods and Materials: We identified 2,184 low-risk, 2,339 intermediate-risk, and 2,897 high-risk patients undergoing EBRT for nonmetastatic prostate cancer diagnosed between January 1, 2004, and December 31, 2005, in the linked Surveillance, Epidemiology, and End Results-Medicare database. We examined the association of patient, clinical, and demographic characteristics with AS use by multivariate logistic regression. Results: The proportions of patients receiving AS for low-risk, intermediate-risk, and high-risk prostate cancer were 32.2%, 56.3%, and 81.5%, respectively. AS use among men in the low-risk disease category varied widely, ranging from 13.6% in Detroit to 47.8% in Kentucky. We observed a significant decline in AS use between 2004 and 2005 within all three disease risk categories. Men aged {>=}75 years or with elevated comorbidity levels were more likely to receive AS. Conclusion: Our results identified apparent overuse and underuse of AS among men within the low-risk and high-risk disease categories, respectively. These results highlight the need for clinician and patient education regarding the appropriate use of AS. Practice patterns among intermediate-risk patients reflect the clinical heterogeneity of this population and underscore the need for better evidence to guide the treatment of these patients.

  5. Prostate Specific Antigen (PSA as Predicting Marker for Clinical Outcome and Evaluation of Early Toxicity Rate after High-Dose Rate Brachytherapy (HDR-BT in Combination with Additional External Beam Radiation Therapy (EBRT for High Risk Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Thorsten H. Ecke

    2016-11-01

    Full Text Available High-dose-rate brachytherapy (HDR-BT with external beam radiation therapy (EBRT is a common treatment option for locally advanced prostate cancer (PCa. Seventy-nine male patients (median age 71 years, range 50 to 79 with high-risk PCa underwent HDR-BT following EBRT between December 2009 and January 2016 with a median follow-up of 21 months. HDR-BT was administered in two treatment sessions (one week interval with 9 Gy per fraction using a planning system and the Ir192 treatment unit GammaMed Plus iX. EBRT was performed with CT-based 3D-conformal treatment planning with a total dose administration of 50.4 Gy with 1.8 Gy per fraction and five fractions per week. Follow-up for all patients was organized one, three, and five years after radiation therapy to evaluate early and late toxicity side effects, metastases, local recurrence, and prostate-specific antigen (PSA value measured in ng/mL. The evaluated data included age, PSA at time of diagnosis, PSA density, BMI (body mass index, Gleason score, D’Amico risk classification for PCa, digital rectal examination (DRE, PSA value after one/three/five year(s follow-up (FU, time of follow-up, TNM classification, prostate volume, and early toxicity rates. Early toxicity rates were 8.86% for gastrointestinal, and 6.33% for genitourinary side effects. Of all treated patients, 84.81% had no side effects. All reported complications in early toxicity were grade 1. PSA density at time of diagnosis (p = 0.009, PSA on date of first HDR-BT (p = 0.033, and PSA on date of first follow-up after one year (p = 0.025 have statistical significance on a higher risk to get a local recurrence during follow-up. HDR-BT in combination with additional EBRT in the presented design for high-risk PCa results in high biochemical control rates with minimal side-effects. PSA is a negative predictive biomarker for local recurrence during follow-up. A longer follow-up is needed to assess long-term outcome and toxicities.

  6. Stereotactic Body Radiotherapy as Monotherapy or Post-External Beam Radiotherapy Boost for Prostate Cancer: Technique, Early Toxicity, and PSA Response

    Energy Technology Data Exchange (ETDEWEB)

    Jabbari, Siavash [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Weinberg, Vivian K. [Biostatistics and Computational Biology Core, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California (United States); Kaprealian, Tania; Hsu, I-Chow; Ma Lijun; Chuang, Cynthia; Descovich, Martina; Shiao, Stephen [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Shinohara, Katsuto [Department of Urology, University of California San Francisco, San Francisco, California (United States); Roach, Mack [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Department of Urology, University of California San Francisco, San Francisco, California (United States); Gottschalk, Alexander R., E-mail: AGottschalk@radonc.ucsf.edu [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States)

    2012-01-01

    Purpose: High dose rate (HDR) brachytherapy has been established as an excellent monotherapy or after external-beam radiotherapy (EBRT) boost treatment for prostate cancer (PCa). Recently, dosimetric studies have demonstrated the potential for achieving similar dosimetry with stereotactic body radiotherapy (SBRT) compared with HDR brachytherapy. Here, we report our technique, PSA nadir, and acute and late toxicity with SBRT as monotherapy and post-EBRT boost for PCa using HDR brachytherapy fractionation. Patients and Methods: To date, 38 patients have been treated with SBRT at University of California-San Francisco with a minimum follow-up of 12 months. Twenty of 38 patients were treated with SBRT monotherapy (9.5 Gy Multiplication-Sign 4 fractions), and 18 were treated with SBRT boost (9.5 Gy Multiplication-Sign 2 fractions) post-EBRT and androgen deprivation therapy. PSA nadir to date for 44 HDR brachytherapy boost patients with disease characteristics similar to the SBRT boost cohort was also analyzed as a descriptive comparison. Results: SBRT was well tolerated. With a median follow-up of 18.3 months (range, 12.6-43.5), 42% and 11% of patients had acute Grade 2 gastrourinary and gastrointestinal toxicity, respectively, with no Grade 3 or higher acute toxicity to date. Two patients experienced late Grade 3 GU toxicity. All patients are without evidence of biochemical or clinical progression to date, and favorably low PSA nadirs have been observed with a current median PSA nadir of 0.35 ng/mL (range, <0.01-2.1) for all patients (0.47 ng/mL, range, 0.2-2.1 for the monotherapy cohort; 0.10 ng/mL, range, 0.01-0.5 for the boost cohort). With a median follow-up of 48.6 months (range, 16.4-87.8), the comparable HDR brachytherapy boost cohort has achieved a median PSA nadir of 0.09 ng/mL (range, 0.0-3.3). Conclusions: Early results with SBRT monotherapy and post-EBRT boost for PCa demonstrate acceptable PSA response and minimal toxicity. PSA nadir with SBRT boost

  7. Preoperative external beam radiotherapy and reduced dose brachytherapy for carcinoma of the cervix: survival and pathological response

    Directory of Open Access Journals (Sweden)

    Pellizzon Antonio

    2007-02-01

    Full Text Available Abstract Purpose To evaluate the pathologic response of cervical carcinoma to external beam radiotherapy (EBRT and high dose rate brachytherapy (HDRB and outcome. Materials and methods Between 1992 and 2001, 67 patients with cervical carcinoma were submitted to preoperative radiotherapy. Sixty-five patients were stage IIb. Preoperative treatment included 45 Gy EBRT and 12 Gy HDRB. Patients were submitted to surgery after a mean time of 82 days. Lymphadenectomy was performed in 81% of patients. Eleven patients with residual cervix residual disease on pathological specimen were submitted to 2 additional insertions of HDRB. Results median follow up was 72 months. Five-year cause specific survival was 75%, overall survival 65%, local control 95%. Complete pelvic pathological response was seen in 40%. Surgery performed later than 80 days was associated with pathological response. Pelvic nodal involvement was found in 12%. Complete pelvic pathological response and negative lymphnodes were associated with better outcome (p = .03 and p = .005. Late grade 3 and 4 urinary and intestinal adverse effects were seen in 12 and 2% of patients. Conclusion Time allowed between RT and surgery correlated with pathological response. Pelvic pathological response was associated with improved outcome. Postoperative additional HDRB did not improve therapeutic results. Treatment was well tolerated.

  8. Combined total body X-ray irradiation and total skin electron beam radiotherapy with an improved technique for mycosis fungoides

    Energy Technology Data Exchange (ETDEWEB)

    Halberg, F.E.; Fu, K.K.; Weaver, K.A.; Zackheim, H.S.; Epstein, E.H. Jr.; Wintroub, B.U.

    1989-08-01

    Twelve consecutive patients with advanced stage mycosis fungoides (MF) were treated with combined total body X ray irradiation (TBI) and total skin electron beam radiotherapy (EBRT). Six had generalized plaque disease and dermatopathic nodes, three had tumor stage disease and node biopsy positive for mycosis fungoides, and three had erythroderma/Sezary syndrome. The treatment regimen consisted of split course total body X ray irradiation, given in twice weekly 15 cGy fractions to 75 cGy, then total skin electron beam radiation therapy given in once weekly 400 cGy fractions to a total dose of 2400 cGy. Underdosed areas and areas of greatest initial involvement were boosted 400 cGy twice weekly for an additional 1200 cGy. This was followed by a second course of total body X ray irradiation, to a total dose of 150 cGy. The total skin electron beam radiotherapy technique is a modification of an established six position EBRT technique for mycosis fungoides. Measurements to characterize the beam with and without a lexan scattering plate, demonstrated that the combination of no-plate beams produced better dose uniformity with a much higher dose rate. This improved technique is particularly advantageous for elderly and/or frail patients. Nine (75%) of the 12 patients achieved complete response (CR). The other three had significant improvement with greater than 80% clearing of their disease and resolution of symptoms. All six patients with generalized plaque disease achieved complete response and remained free of disease from 2 to 16 months. Two of three node positive patients also achieved complete response; one, with massive biopsy-documented mycosis fungoides nodal disease and deep open tumors, remained relapse-free over 2 years. Only one of the three patients with erythroderma/Sezary syndrome achieved a complete response, which was short lived.

  9. Intraoperative EBRT and resection for renal cell carcinoma. Twenty-year outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, F.A. [Hospital Gneral Universitario Gregorio Maranon, Madrid (Spain). Dept. of Oncology; Complutense Univ., Madrid (Spain). School of Medicine; Sole, C.V. [Hospital Gneral Universitario Gregorio Maranon, Madrid (Spain). Dept. of Oncology; Complutense Univ., Madrid (Spain). School of Medicine; Instituto de Radiomedicina, Santiago (Spain). Service of Radiation Oncology; Martinez-Monge, R.; Aristu, J. [Clinica Universitaria de Navarra, Pamplona (Spain). Dept. of Radiation Oncology; Azinovic, I. [Hospital de San Jaime, Torrevieja (Spain). Dept. of Radiation Oncology; Zudaire, J.; Berian, J.M. [Clinica Universitaria de Navarra, Pamplona (Spain). Dept. of Urology; Garcia-Sabrido, J.L. [Hospital General Universitario Gregorio Maranon, Madrid (Spain). Dept. of General Surgery

    2013-02-15

    Purpose: We report the outcomes of a multimodality treatment approach combining maximal surgical resection and intraoperative electron radiotherapy (IOERT) with or without external beam radiation therapy (EBRT) in patients with locoregionally (LR) recurrent renal cell carcinoma (RCC) after radical nephrectomy or LR advanced primary RCC. Patients and methods: From 1983 to 2008, 25 patients with LR recurrent (n = 10) or LR advanced primary (n = 15) RCC were treated with this approach. Median patient age was 60 years (range, 16-79 years). Fifteen patients (60%) received perioperative EBRT (median dose, 44 Gy). Surgical resection was R0 (negative margins) in 6 patients (24%) and R1 (residual microscopic disease) in 19 patients (76%). The median dose of IOERT was 14 Gy (range, 9-15). Overall survival (OS) and relapse patterns were calculated using the Kaplan-Meier method. Results: Median follow-up for surviving patients was 22.2 years (range, 3.6-26 years). OS and DFS at 5 and 10 years were 38% and 18% and 19% and 14%, respectively. LR control (tumor bed or regional lymph nodes) and distant metastases-free survival rates at 5 years were 80% and 22%, respectively. The death rate within 30 days of surgery and IOERT was 4% (n = 1). Six patients (24%) experienced acute or late toxicities of grade 3 or higher according to the National Cancer Institute Common Toxicity Criteria (NCI-CTCAE) v4. Conclusion: In patients with LR recurrent or LR advanced primary RCC, a multimodality approach consisting of maximal surgical resection and IOERT with or without adjuvant EBRT yielded encouraging local control results, justifying further evaluation. (orig.)

  10. Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus [University Medical Center Hamburg-Eppendorf, Martini-Clinic Prostate Cancer Center, Hamburg (Germany); Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf [University Medical Center Hamburg-Eppendorf, Department of Radiation oncology, Hamburg (Germany)

    2015-04-01

    The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [German] Der Nutzen einer zusaetzlichen Hormonentzugstherapie (ADT, ''androgen deprivation therapy'') fuer Patienten mit Prostatakarzinom (PCa), welche mit einer Kombination aus HDR-Brachytherapie (HDR-BT) und perkutaner Bestrahlung (EBRT) behandelt werden, ist weiterhin ungeklaert. Fuer diese Studie wurden konsekutive, nach der D'Amico-Risikoklassifizierung in ''intermediate'' und ''high-risk'' eingeteilte Patienten ausgewaehlt, die zwischen Januar 1999 und Februar 2009 in unserem Institut eine kombinierte Therapie aus HDR-BT, EBRT ± ADT erhalten haben. Eine

  11. The effect of short term neo-adjuvant androgen deprivation on erectile function in patients treated with external beam radiotherapy for localised prostate cancer: an analysis of the 4- versus 8-month randomised trial (Irish Clinical Oncology Research Group 97-01).

    LENUS (Irish Health Repository)

    Daly, Patricia E

    2012-07-01

    Erectile dysfunction is a common consequence of external beam radiotherapy (EBRT) for prostate cancer. The addition of neo-adjuvant androgen deprivation (NAD) has an indeterminate additive effect. We examined the long-term effect on erectile function (EF) of two durations (4 months: arm 1 and 8 months: arm 2) of NAD prior to radiation (RT) for patients with localised prostate cancer from the Irish Clinical Oncology Research Group (ICORG 97-01) 4- versus 8-month trial. In this study we aimed to (1) analyse the overall effect on EF of NAD in an EBRT population, (2) compare the probability of retained EF over time in an EBRT population treated with either 4 or 8 months of NAD and (3) identify any variables such as risk group and age which may have an additive detrimental effect. This analysis provides unique long term follow up data.

  12. 20 Gy Versus 44 Gy of Supplemental External Beam Radiotherapy With Palladium-103 for Patients With Greater Risk Disease: Results of a Prospective Randomized Trial

    Energy Technology Data Exchange (ETDEWEB)

    Merrick, Gregory S., E-mail: gmerrick@urologicresearchinstitute.org [Schiffler Cancer Center/Wheeling Jesuit University, Wheeling, WV (United States); Wallner, Kent E. [Puget Sound Healthcare Corporation, University of Washington, Seattle, WA (United States); Butler, Wayne M.; Galbreath, Robert W. [Schiffler Cancer Center/Wheeling Jesuit University, Wheeling, WV (United States); Taira, Al V. [Western Radiation Oncology Inc, Mountain View, CA (United States); Orio, Peter [Department of Radiation Oncology, Dana Farber Cancer Institute/Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Adamovich, Edward [Department of Pathology, Wheeling Hospital, Wheeling, WV (United States)

    2012-03-01

    Purpose: The necessity of external beam radiotherapy (EBRT) as a supplement to prostate brachytherapy remains unknown. We report brachytherapy outcomes for patients with higher risk features randomized to substantially different supplemental EBRT regimens. Methods and Materials: Between December 1999 and June 2004, 247 patients were randomized to 20 Gy vs. 44 Gy EBRT followed by a palladium-103 boost (115 Gy vs. 90 Gy). The eligibility criteria included clinically organ-confined disease with Gleason score 7-10 and/or pretreatment prostate-specific antigen (PSA) level 10-20 ng/mL. The median follow-up period was 9.0 years. Biochemical progression-free survival (bPFS) was defined as a PSA level of {<=}0.40 ng/mL after nadir. The median day 0 prescribed dose covering 90% of the target volume was 125.7%; 80 men received androgen deprivation therapy (median, 4 months). Multiple parameters were evaluated for their effect on bPFS. Results: For the entire cohort, the cause-specific survival, bPFS, and overall survival rates were 97.7%, 93.2%, and 80.8% at 8 years and 96.9%, 93.2%, and 75.4% at 10 years, respectively. The bPFS rate was 93.1% and 93.4% for the 20-Gy and 44-Gy arms, respectively (p = .994). However, no statistically significant differences were found in cause-specific survival or overall survival were identified. When stratified by PSA level of {<=}10 ng/mL vs. >10 ng/mL, Gleason score, or androgen deprivation therapy, no statistically significant differences in bPFS were discerned between the two EBRT regimens. On multivariate analysis, bPFS was most closely related to the preimplant PSA and clinical stage. For patients with biochemically controlled disease, the median PSA level was <0.02 ng/mL. Conclusion: The results of the present trial strongly suggest that two markedly different supplemental EBRT regimens result in equivalent cause-specific survival, bPFS, and overall survival. It is probable that the lack of benefit for a higher supplemental EBRT dose

  13. Clinical outcome in patients with prostate cancer treated with external beam radiotherapy and high dose-rate iridium 192 brachytherapy boost: A 6-year follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Kaelkner, Karl Mikael; Wahlgren, Thomas; Ryberg, Marianne; Cohn-Cedermark, G abriella; Castellanos, Enrique; Nilsson, Sten [Dept. of Oncology-Pathology, Radi umhemmet, Karolinska Univ. Hospital and Inst., Stockholm (Sweden); Zimmerman, Rolf [Dept. of Oncology-Pathology, Soedersjukhuset, Karolinska Univ. Hospital and Inst., Stockh olm (Sweden); Nilsson, Josef; Lundell, Marie [Dept. of Medical Physics, Karolinska Univ. Hospital and Inst., Stockholm (Sweden); Fowler, Jack [Dept. of Human Oncology , Univ. of Wisconsin Medical School, Madison (United States); Levitt, Seymour [Dept. of Therapeutic R adiology, Univ. of Minnesota, Minneapolis, MN (United States); Hellstroem, Magnus [Dept. o f Urology, Karolinska Univ. Hospital and Inst., Stockholm (Sweden)

    2007-10-15

    To report the long-term results for treatment of localized carcinoma of the prostate using high dose rate (HDR) brachytherapy, conformal external beam radiotherapy (3D EBRT) and neo-adjuvant hormonal therapy (TAB). From 1998 through 1999, 154 patients with localized prostate cancer were entered in the trial. Biologically no evidence of disease (bNED) was defined at PSA levels < 2 {mu}g/l. In order to compare the results of this treatment with other treatment modalities, the patient's pre-treatment data were used to calculate the estimated 5-year PSA relapse free survival using Kattan's nomograms for radical prostatectomy (RP) and 3D EBRT. After 6 years of follow-up, 129 patients remain alive. The actual 5-year relapse-free survival is 84%. None of the patients demonstrated clinical signs of local recurrence. The median PSA at follow-up among the relapse-free patients was 0.05 {mu}g/l. Among the 80 patients who presented with clinical stage T3 tumours, 55 (68%) were relapse-free. The expected 5-year relapse-free survival using nomograms for RP and 3D EBRT was 54% and 70%, respectively. Late rectal toxicity RTOG grade 3 occurred in 1% of the patients. Late urinary tract toxicity RTOG grade 3 developed in 4% of the patients. Combined treatment, utilizing HDR, 3D EBRT and TAB, produces good clinical results. Rectal toxicity is acceptable. Urinary tract toxicity, most likely can be explained by the fact that during the first years of this treatment, no effort was made to localize the urethra, which was assumed to be in the middle of the prostate.

  14. Characterization of a homemade ionization chamber for radiotherapy beams.

    Science.gov (United States)

    Neves, Lucio P; Perini, Ana P; dos Santos, Gelson P; Xavier, Marcos; Khoury, Helen J; Caldas, Linda V E

    2012-07-01

    A homemade cylindrical ionization chamber was studied for routine use in therapy beams of (60)Co and X-rays. Several characterization tests were performed: leakage current, saturation, ion collection efficiency, polarity effect, stability, stabilization time, chamber orientation and energy dependence. All results obtained were within international recommendations. Therefore the homemade ionization chamber presents usefulness for routine dosimetric procedures in radiotherapy beams.

  15. A Investigation of Radiotherapy Electron Beams Using Monte Carlo Techniques

    Science.gov (United States)

    Ding, George X.

    1995-01-01

    Radiotherapy electron beams are more complicated than photon beams due to variations in the beam production, the scattering of low-energy electrons, and the presence contaminant photons. The detailed knowledge of a radiotherapy beam is essential to an accurate calculation of dose distribution for a treatment planning system. This investigation aims to enhance our understanding of radiotherapy beams by focusing on electron beams used in radiotherapy. It starts with a description of the Monte Carlo simulation code, BEAM, and a detailed simulation of an accelerator head to obtain realistic radiotherapy beams. The simulation covers electron beams from various accelerators, including the NRC research accelerator, the NPL (UK), accelerator, A Varian Clinac 2100C, a Philips SL75-20, a Siemens KD2, an AECL Therac 20, and a Scanditronix MM50. The beam energies range from 4 to 50 MeV. The EGS4 user code, BEAM, is extensively benchmarked against experiment by comparing calculated dose distributions with measured dose distributions in water. The simulated beams are analyzed to obtain the characteristics of various electron beams from a variety of accelerators. The simulated beams are also used as inputs to calculate the following parameters: the mean electron energy, the most probable energy, the energy-range relationships, the depth-scaling factor to convert depths in plastic to water-equivalent depths, the water-to-air stopping-power ratios, and the electron fluence correction factors used to convert dose measured in plastics to dose in water. These parameters are essential for electron beam dosimetry. The results from this study can be applied in cancer clinics to improve the accuracy of the absolute dosimetry. The simulation also provides information about the backscatter into the beam monitor chamber, and predicts the influence on the beam output factors. This investigation presents comprehensive data on the clinical electron beams, and answers many questions which could

  16. Impact of the target volume (prostate alone vs. prostate with seminal vesicles) and fraction dose (1.8 Gy vs. 2.0 Gy) on quality of life changes after external-beam radiotherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Eble, Michael J. [Dept. of Radiotherapy, RWTH Aachen (Germany); Pinkawa, Michael; Piroth, Marc D.; Fischedick, Karin; Holy, Richard; Klotz, Jens; Nussen, Sandra; Krenkel, Barbara

    2009-11-15

    Purpose: to evaluate the impact of the clinical target volume (CTV) and fraction dose on quality of life (QoL) after external-beam radiotherapy (EBRT) for prostate cancer. Patients and methods: a group of 283 patients has been surveyed prospectively before, at the last day, at a median time of 2 months and 15 months after EBRT (70.2-72 Gy) using a validated questionnaire (Expanded Prostate Cancer Index Composite). FBRT of prostate alone (P, n = 70) versus prostate with seminal vesicles (PS, n = 213) was compared. Differences of fraction doses (1.8 Gy, n = 80, vs. 2.0 Gy, n = 69) have been evaluated in the patient group receiving a total dose of 72 Gy. Results: significantly higher bladder and rectum volumes were found at all dose levels for the patients with PS versus P within the CTV (p < 0.001). Similar volumes resulted in the groups with different fraction doses. Paradoxically, bowel function scores decreased significantly less 2 and 15 months after EBRT of PS versus P. 2 months after EBRT, patients with a fraction dose of 2.0 Gy versus 1.8 Gy reported pain with urination ({>=} once a day in 12% vs. 3%; p = 0.04) and painful bowel movements ({>=} rarely in 46% vs. 29%; p = 0.05) more frequently. No long-term differences were found. Conclusion: the risk of adverse QoL changes after EBRT for prostate cancer cannot be derived from the dose-volume histogram alone. Seminal vesicles can be included in the CTV up to a moderate total dose without adverse effects on QoL. Apart from a longer recovery period, higher fraction doses were not associated with higher toxicity. (orig.)

  17. Qualitative accounts of patients' determinants of vaginal dilator use after pelvic radiotherapy

    NARCIS (Netherlands)

    R.M. Bakker (Rinske M.); W. Vermeer (Willemijn); C.L. Creutzberg (Carien); J.W.M. Mens (Jan); R.A. Nout; M.M. ter Kuile (Moniek)

    2015-01-01

    textabstractIntroduction: Treatment with pelvic external beam radiotherapy with brachytherapy (EBRT/BT) for gynecological cancers may cause sexual dysfunction because of vaginal shortening and tightening. Regular vaginal dilator use is thought to reduce vaginal shortening and/or tightening, but comp

  18. External Beam Radiation in Differentiated Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Salem Billan

    2016-01-01

    Full Text Available The treatment of differentiated thyroid carcinoma (DTC is surgery followed in some cases by adjuvant treatment, mostly with radioactive iodine (RAI. External beam radiotherapy (EBRT is less common and not a well-established treatment modality in DTC. The risk of recurrence depends on three major prognostic factors: extra-thyroid extension, patient’s age, and tumor with reduced iodine uptake. Increased risk for recurrence is a major factor in the decision whether to treat the patient with EBRT. Data about the use of EBRT in DTC are limited to small retrospective studies. Most series have demonstrated an increase in loco-regional control. The risk/benefit from giving EBRT requires careful patient selection. Different scoring systems have been proposed by different investigators and centers. The authors encourage clinicians treating DTC to become familiarized with those scoring systems and to use them in the management of different cases. The irradiated volume should include areas of risk for microscopic disease. Determining those areas in each case can be difficult and requires detailed knowledge of the surgery and pathological results, and also understanding of the disease-spreading pattern. Treatment with EBRT in DTC can be beneficial, and data support the use of EBRT in high-risk patients. Randomized controlled trials are needed for better confirmation of the role of EBRT.

  19. External beam radiotherapy synergizes 188Re-liposome against human esophageal cancer xenograft and modulates 188Re-liposome pharmacokinetics

    Directory of Open Access Journals (Sweden)

    Chang CH

    2015-05-01

    Full Text Available Chih-Hsien Chang,1,2 Shin-Yi Liu,3 Chih-Wen Chi,3 Hsiang-Lin Yu,1 Tsui-Jung Chang,1 Tung-Hu Tsai,4 Te-Wei Lee,1 Yu-Jen Chen3–5 1Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan; 2Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, 3Department of Medical Research MacKay Memorial Hospital, 4Institute of Traditional Medicine, National Yang-Ming University, 5Department of Radiation Oncology, MacKay Memorial Hospital, Taipei, Taiwan Abstract: External beam radiotherapy (EBRT treats gross tumors and local microscopic diseases. Radionuclide therapy by radioisotopes can eradicate tumors systemically. Rhenium 188 (188Re-liposome, a nanoparticle undergoing clinical trials, emits gamma rays for imaging validation and beta rays for therapy, with biodistribution profiles preferential to tumors. We designed a combinatory treatment and examined its effects on human esophageal cancer xenografts, a malignancy with potential treatment resistance and poor prognosis. Human esophageal cancer cell lines BE-3 (adenocarcinoma and CE81T/VGH (squamous cell carcinoma were implanted and compared. The radiochemical purity of 188Re-liposome exceeded 95%. Molecular imaging by NanoSPECT/CT showed that BE-3, but not CE81T/VGH, xenografts could uptake the 188Re-liposome. The combination of EBRT and 188Re-liposome inhibited tumor regrowth greater than each treatment alone, as the tumor growth inhibition rate was 30% with EBRT, 25% with 188Re-liposome, and 53% with the combination treatment at 21 days postinjection. Combinatory treatment had no additive adverse effects and significant biological toxicities on white blood cell counts, body weight, or liver and renal functions. EBRT significantly enhanced the excretion of 188Re-liposome into feces and urine. In conclusion, the combination of EBRT with 188Re-liposome might be a potential treatment modality for esophageal cancer. Keywords: Radionuclide

  20. TECHNOLOGIES FOR DELIVERY OF PROTON AND ION BEAMS FOR RADIOTHERAPY

    CERN Document Server

    Owen, H; Alonso, J; Mackay, R

    2014-01-01

    Recent developments for the delivery of proton and ion beam therapy have been significant, and a number of technological solutions now exist for the creation and utilisation of these particles for the treatment of cancer. In this paper we review the historical development of particle accelerators used for external beam radiotherapy and discuss the more recent progress towards more capable and cost-effective sources of particles.

  1. Technologies for Delivery of Proton and Ion Beams for Radiotherapy

    CERN Document Server

    Owen, Hywel; Alonso, Jose; MacKay, Ranald

    2013-01-01

    Recent developments for the delivery of proton and ion beam therapy have been significant, and a number of technological solutions now exist for the creation and utilisation of these particles for the treatment of cancer. In this paper we review the historical development of particle accelerators used for external beam radiotherapy and discuss the more recent progress towards more capable and cost-effective sources of particles.

  2. Intraoperative radiotherapy:principles and prospects

    Institute of Scientific and Technical Information of China (English)

    Omar Abdel-Rahman

    2014-01-01

    Intraoperative radiotherapy (IORT) in its broadest sense refers to the delivery of radiation at the time of an opera-tion. It includes multiple techniques, namely intraoperative electron irradiation, intraoperative brachytherapy and intraopera-tive photon irradiation. It has a wide range of existing and potential y enlarging clinical applications. We wil discuss in this review the rationale for and use of intraoperative irradiation in conjunction with surgical exploration with or without external-beam irradiation (EBRT) and chemotherapy.

  3. Improving anatomical mapping of complexly deformed anatomy for external beam radiotherapy and brachytherapy dose accumulation in cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Vásquez Osorio, Eliana M., E-mail: e.vasquezosorio@erasmusmc.nl; Kolkman-Deurloo, Inger-Karine K.; Schuring-Pereira, Monica; Zolnay, András; Heijmen, Ben J. M.; Hoogeman, Mischa S. [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam 3075 (Netherlands)

    2015-01-15

    Purpose: In the treatment of cervical cancer, large anatomical deformations, caused by, e.g., tumor shrinkage, bladder and rectum filling changes, organ sliding, and the presence of the brachytherapy (BT) applicator, prohibit the accumulation of external beam radiotherapy (EBRT) and BT dose distributions. This work proposes a structure-wise registration with vector field integration (SW+VF) to map the largely deformed anatomies between EBRT and BT, paving the way for 3D dose accumulation between EBRT and BT. Methods: T2w-MRIs acquired before EBRT and as a part of the MRI-guided BT procedure for 12 cervical cancer patients, along with the manual delineations of the bladder, cervix-uterus, and rectum-sigmoid, were used for this study. A rigid transformation was used to align the bony anatomy in the MRIs. The proposed SW+VF method starts by automatically segmenting features in the area surrounding the delineated organs. Then, each organ and feature pair is registered independently using a feature-based nonrigid registration algorithm developed in-house. Additionally, a background transformation is calculated to account for areas far from all organs and features. In order to obtain one transformation that can be used for dose accumulation, the organ-based, feature-based, and the background transformations are combined into one vector field using a weighted sum, where the contribution of each transformation can be directly controlled by its extent of influence (scope size). The optimal scope sizes for organ-based and feature-based transformations were found by an exhaustive analysis. The anatomical correctness of the mapping was independently validated by measuring the residual distances after transformation for delineated structures inside the cervix-uterus (inner anatomical correctness), and for anatomical landmarks outside the organs in the surrounding region (outer anatomical correctness). The results of the proposed method were compared with the results of the

  4. Characterization of a homemade ionization chamber for radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Lucio P., E-mail: lpneves@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Perini, Ana P., E-mail: aperini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Santos, Gelson P. dos, E-mail: gpsantos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Xavier, Marcos, E-mail: mxavier@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.br [Universidade Federal de Pernambuco, Departamento de Energia Nuclear, Av. Prof. Luiz Freire 1000, 50740-540 Recife (Brazil); Caldas, Linda V.E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil)

    2012-07-15

    A homemade cylindrical ionization chamber was studied for routine use in therapy beams of {sup 60}Co and X-rays. Several characterization tests were performed: leakage current, saturation, ion collection efficiency, polarity effect, stability, stabilization time, chamber orientation and energy dependence. All results obtained were within international recommendations. Therefore the homemade ionization chamber presents usefulness for routine dosimetric procedures in radiotherapy beams. - Highlights: Black-Right-Pointing-Pointer A homemade ionization chamber was studied for routine use in radiotherapy. Black-Right-Pointing-Pointer Several characterization tests were performed and the results were satisfactory. Black-Right-Pointing-Pointer This chamber was compared to commercial ones and the results were similar. Black-Right-Pointing-Pointer This chamber is suitable for calibration procedures in {sup 60}Co beams.

  5. A Device for a Proton Beam Energy Control for Radiotherapy

    CERN Document Server

    Agapov, A V; Molokanov, A G; Shvidkii, S V

    2004-01-01

    A Medical-Technical Facility for hadron radiotherapy based on DLNP JINR phasotron has been constructed and put into operation. Upgrading of methods, hardware and software for radiotherapy is one of the main tasks for further development of the Facility. This article concerns one of the fields of this work, that is the development of equipment for dynamic irradiation of deep lying target - the construction of a device for the proton beam energy control and measurement of its depth-dose curve in a treatment room.

  6. Compensation techniques in NIRS proton beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Akanuma, A. (Univ. of Tokyo, Japan); Majima, H.; Furukawa, S.

    1982-09-01

    Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods.

  7. Monte Carlo radiation transport in external beam radiotherapy

    OpenAIRE

    Çeçen, Yiğit

    2013-01-01

    The use of Monte Carlo in radiation transport is an effective way to predict absorbed dose distributions. Monte Carlo modeling has contributed to a better understanding of photon and electron transport by radiotherapy physicists. The aim of this review is to introduce Monte Carlo as a powerful radiation transport tool. In this review, photon and electron transport algorithms for Monte Carlo techniques are investigated and a clinical linear accelerator model is studied for external beam radiot...

  8. Optimisation of beam-orientations in conformal radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Rowbottom, C.G

    1999-07-01

    Many synergistic advances have led to the beginnings of the routine use of conformal radiotherapy. These include advances in diagnostic imaging, in 3D treatment planning, in the technology for complex treatment delivery and in computer assessment of rival treatment plans. A conformal radiotherapy treatment plan more closely conforms the high-dose volume to the target volume, reducing the dose to normal healthy tissue. Traditionally, human planners have devised the treatment parameters used in radiotherapy treatment plans via a manually iterative process. Computer 'optimisation' algorithms have been shown to improve treatment plans as they can explore much more of the search space in a relatively short time. This thesis examines beam-orientation computer 'optimisation' in radiotherapy treatment planning and several new techniques were developed. Using these techniques a comparison was performed between treatment plans with 'standard', fixed beam-orientations and treatment plans with 'optimised' beam-orientations for patients with cancer of the prostate, oesophagus and brain. Plans were compared on the basis of dose-distributions and in some cases biological models for the probability of damage to the target volume and the major organs-at-risk (OARs) in each patient group. A cohort of patients was considered in each group to avoid bias from a specific patient geometry. In the case of the patient cohort with cancer of the prostate, a coplanar beam-orientation 'optimisation' scheme led to an average increase in the TCP of (5.7{+-}1.4)% compared to the standard plans after the dose to the isocentre had been scaled to produce a rectal NTCP of 1%. For the patient cohort with cancer of the oesophagus, the beam-orientation 'optimisation' scheme reduced the average lung NTCP by (0.7{+-}0.2)% at the expense of a modest increase in the average spinal cord NTCP of (0.1{+-}0.2)%. A non-coplanar beam-orientation &apos

  9. Diaphragm motion characterization using chest motion data for biomechanics-based lung tumor tracking during EBRT

    Science.gov (United States)

    Karami, Elham; Gaede, Stewart; Lee, Ting-Yim; Samani, Abbas

    2016-03-01

    Despite recent advances in image-guided interventions, lung cancer External Beam Radiation Therapy (EBRT) is still very challenging due to respiration induced tumor motion. Among various proposed methods of tumor motion compensation, real-time tumor tracking is known to be one of the most effective solutions as it allows for maximum normal tissue sparing, less overall radiation exposure and a shorter treatment session. As such, we propose a biomechanics-based real-time tumor tracking method for effective lung cancer radiotherapy. In the proposed algorithm, the required boundary conditions for the lung Finite Element model, including diaphragm motion, are obtained using the chest surface motion as a surrogate signal. The primary objective of this paper is to demonstrate the feasibility of developing a function which is capable of inputting the chest surface motion data and outputting the diaphragm motion in real-time. For this purpose, after quantifying the diaphragm motion with a Principal Component Analysis (PCA) model, correlation coefficient between the model parameters of diaphragm motion and chest motion data was obtained through Partial Least Squares Regression (PLSR). Preliminary results obtained in this study indicate that the PCA coefficients representing the diaphragm motion can be obtained through chest surface motion tracking with high accuracy.

  10. Treatment results of radical radiotherapy of carcinoma uterine cervix using external beam radiotherapy and high dose rate intracavitary radiotherapy

    Directory of Open Access Journals (Sweden)

    Azad S

    2010-01-01

    Full Text Available Aim: To report the outcome of carcinoma cervix patients treated radically by external beam radiotherapy and high dose rate intracavitary radiotherapy. Material and Methods: From January 2005 to December 2006, a total of 709 newly diagnosed cases of carcinoma cervix were reported in our department. All cases were staged according to the International Federation of Gynecologist and Oncologist staging system. Out of 709 cases, 342 completed radical radiotherapy and were retrospectively analyzed for the presence of local residual disease, local recurrence, distant metastases, radiation reaction, and disease free survival. Results: There were 11(3.22%, 82(23.98%, 232(67.83%, and 17(4.97% patients in stages I, II, III, and IV, respectively. The median follow up time for all patients was 36 months (range 3 -54 months. The overall treatment time (OTT ranged from 52 to 69 days (median 58 days. The 3 year disease free survival rate was 81.8%, 70.7%, 40.08%, and 11.76% for stages I, II, III, and IV, respectively. There were 91 (26.6% cases with local residual diseases, 27(7.9% developed distant metastasis, and 18(5.26% pts had local recurrence. Discussion: The results of this study suggest that radical radiotherapy with HDR brachytherapy was appropriate for the treatment of early staged cancer of uterine cervix. For locally advanced cancer of cervix addition of concurrent chemotherapy, higher radiation doses, reduction of overall treatment time to less than 8 weeks, and use of latest radiotherapy techniques such as IMRT is recommended to improve the results.

  11. Modelling beam transport and biological effectiveness to develop treatment planning for ion beam radiotherapy

    CERN Document Server

    Grzanka, Leszek

    2014-01-01

    Radiation therapy with carbon ions is a novel technique of cancer radiotherapy, applicable in particular to treating radioresistant tumours at difficult localisations. Therapy planning, where the medical physicist, following the medical prescription, finds the optimum distribution of cancer cells to be inactivated by their irradiation over the tumour volume, is a basic procedure of cancer radiotherapy. The main difficulty encountered in therapy planning for ion radiotherapy is to correctly account for the enhanced radiobiological effectiveness of ions in the Spread Out Bragg Peak (SOBP) region over the tumour volume. In this case, unlike in conventional radiotherapy with photon beams, achieving a uniform dose distribution over the tumour volume does not imply achieving uniform cancer cell inactivation. In this thesis, an algorithm of the basic element (kernel) of a treatment planning system (TPS) for carbon ion therapy is developed. The algorithm consists of a radiobiological part which suitably corrects for ...

  12. Intraoperative and external beam radiotherapy for pancreatic carcinoma; Intraoperative und perkutane Radiotherapie des Pankreaskarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Eble, M.J. [Abt. Klinische Radiologie, Radiologische Universitaetsklinik Heidelberg (Germany); Maurer, U. [Klinikum der Stadt Mannheim (Germany). Inst. fuer Radiologie

    1996-05-01

    Therapeutic strategies in the treatment of pancreatic carcinoma are based on the high number of non-resectable cancers, the high relative radioresistance and the high distant metastases rate. Even in curatively resected carcinomas, a locally effective treatment modality is needed because of the risk of microscopical residual disease in the peripancreatic tissue. The efficacy of radiotherapy is dose dependent. Based on an analysis of published data a dose of more than 50 Gy is recommended, resulting in a high morbidity rate with external beam radiotherapy alone. The use of intraoperative radiotherapy allows locally restricted dose escalation without increased perioperative morbidity. In adjuvant and in primary treatment, local tumor control was improved (70-90%). With palliative intent, pain relief was obtained rapidly in over 60% of patients and led to improved patient performance. As a result of the high distant metastases rate, even in curatively resected carcinomas, the overall prognosis could not be significantly improved. Further dose escalation is limited by the increasing incidence of upper gastrointestinal bleeding (20-30%). (orig.) [Deutsch] Therapiestrategien beim Pankreaskarzinom werden bestimmt durch den hohen Anteil primaer nicht resektabler Karzinome, der hohen relativen Strahlenresistenz und der hohen Fernmetastasierungsrate. Selbst kurativ resezierte Karzinome erfordern durch ihre hohe lokale Tumorzellpersistenz eine lokal effektive adjuvante Behandlungsmassnahme. Die Effektivitaet einer Radiotherapie ist dosisabhaengig. Aus der Analyse publizierter Daten wird eine Dosis von >50 Gy, welche bei der alleinigen perkutanen Bestrahlung mit einer hohen Morbiditaet verbunden ist, empfohlen. Mit der intraoperativen Radiotherapie ist eine lokal begrenzte Dosiseskalation ohne erhoehte perioperative Morbiditaet moeglich. Sowohl in der adjuvanten als auch in der primaeren Behandlung kann die lokale Tumorkontrolle deutlich verbessert werden (70-90%). Unter

  13. Visual functioning and quality of life in the subfoveal radiotherapy study (SFRADS): SFRADS report 2

    OpenAIRE

    Stevenson, Michael; Hart, P M; Chakravarthy, Usha; Mackenzie, G; Bird, A C; Owens, S.L.; Chisholm, J.H.; Hall, V; Houston, R F; McCulloch, D W; Plowman, N.

    2005-01-01

    Aims: To determine whether or not self reported visual functioning and quality of life in patients with choroidal neovascularisation caused by age related macular degeneration (AMD) is better in those treated with 12 Gy external beam radiotherapy in comparison with untreated subjects. Methods: A multicentre single masked randomised controlled trial of 12 Gy of external beam radiation therapy (EBRT) delivered as 6x2 Gy fractions to the macula of an affected eye versus observation. Patients wit...

  14. Combined external beam and intraluminal radiotherapy for irresectable Klatskin tumors

    Energy Technology Data Exchange (ETDEWEB)

    Schleicher, U.M. [Klinik fuer Strahlentherapie, Technische Hochschule Aachen (Germany); Staatz, G. [Klinik fuer Radiologische Diagnostik, Technische Hochschule Aachen (Germany); Alzen, G. [Klinik fuer Radiologische Diagnostik, Technische Hochschule Aachen (Germany); Abt. Kinderradiologie, Giessen Univ. (Germany); Andreopoulos, D. [Klinik fuer Strahlentherapie, Technische Hochschule Aachen (Germany); BOC Oncology Centre, Nikosia (Cyprus)

    2002-12-01

    Background: In most cases of proximal cholangiocarcinoma, curative surgery is not possible. Radiotherapy can be used for palliative treatment. We report our experience with combined external beam and intraluminal radiotherapy of advanced Klatskin's tumors. Patients and Methods: 30 patients were treated for extrahepatic proximal bile duct cancer. Our schedule consisted for external beam radiotherapy (median dose 30 Gy) and a high-dose-rate brachytherapy boost (median dose 40 Gy) delivered in four or five fractions, which could be applied completely in twelve of our patients. 15 patients in the brachytherapy and nine patients in the non-brachytherapy group received additional low-dose chemotherapy with 5-fluorouracil. Results: The brachytherapy boost dose improved the effect of external beam radiotherapy by increasing survival from a median of 3.9 months in the non-brachytherapy group to 9.1 months in the brachytherapy group. The effect was obvious in patients receiving a brachytherapy dose above 30 Gy, and in those without jaundice at the beginning of radiotherapy (p<0.05). Conclusions: The poor prognosis in patients with advanced Klatskin's tumors may be improved by combination therapy, with the role of brachytherapy and chemotherapy still to be defined. Our results suggest that patients without jaundice should be offered brachytherapy, and that a full dose of more than 30 Gy should be applied. (orig.) [German] Hintergrund: Bei den meisten Patienten mit proximalen Cholangiokarzinomen ist eine kurative Operation nicht mehr moeglich. Im Rahmen der Palliativbehandlung kann die Strahlentherapie eingesetzt werden. Wir berichten ueber unsere Erfahrungen mit der Kombination aus perkutaner und intraluminaler Strahlentherapie fortgeschrittener Klatskin-Tumoren. Patienten und Methode: 30 Patienten wurden wegen extrahepatischer proximaler Gallengangskarzinome behandelt. Unser Therapieschema umfasste eine perkutane Strahlentherapie (mediane Dosis: 30 Gy) sowie einen

  15. External beam radiotherapy as curative treatment of prostate cancer.

    Science.gov (United States)

    Pisansky, Thomas M

    2005-07-01

    External beam radiotherapy (RT) has been used as a curative treatment of prostate cancer for more than 5 decades, with the "modern" era emerging more than 3 decades ago. Its history is marked by gradual improvements punctuated by several quantum leaps that are increasingly driven by advancements in the computer and imaging sciences and by its integration with complementary forms of treatment. Consequently, the contemporary use of external beam RT barely resembles its earliest form, and this must be appreciated in the context of current patient care. The influence of predictive factors on the use and outcomes of external beam RT is presented, as is a selected review of the methods and outcomes of external beam RT as a single therapeutic intervention, in association with androgen suppression, or as a postoperative adjunct. Thus, the "state of the (radiotherapeutic) art" is presented to enhance the understanding of this treatment approach with the hope that this information will serve as a useful resource to physicians as they care for patients with prostate cancer.

  16. Does obesity hinder radiotherapy in endometrial cancer patients? The implementation of new techniques in adjuvant radiotherapy – focus on obese patients

    Directory of Open Access Journals (Sweden)

    Małgorzata Moszyńska-Zielińska

    2014-05-01

    Full Text Available The increasing incidence of obesity in Poland and its relation to endometrioid endometrial cancer (EEC is resulting in the increasing necessity of treating obese women. Treatment of an overweight patient with EEC may impede not only the surgical procedures but also radiotherapy, especially external beam radiotherapy (EBRT. The problems arise both during treatment planning and when delivering each fraction due to the difficulty of positioning such a patient – it implies the danger of underdosing targets and overdosing organs at risk. Willingness to use dynamic techniques in radiation oncology has increased for patients with EEC, even those who are obese. During EBRT careful daily verification is necessary for both safety and treatment accuracy. The most accurate method of verification is cone beam computed tomography (CBCT with soft tissue assessment, although it is time consuming and often requires a radiation oncologist. In order to improve the quality of such treatment, the authors present the practical aspects of planning and treatment itself by means of dynamic techniques in EBRT. The authors indicate the advantages and disadvantages of different types of on-board imaging (OBI verification images. Considering the scanty amount of literature in this field, it is necessary to conduct further research in order to highlight proper planning and treatment of obese endometrial cancer patients. The review of the literature shows that all centres that wish to use EBRT for gynaecological tumours should develop their own protocols on qualification, planning the treatment and methods of verifying the patients’ positioning.

  17. Objective assessment of cosmetic outcome after targeted intraoperative radiotherapy in breast cancer

    DEFF Research Database (Denmark)

    Keshtgar, Mohammed R S; Williams, Norman R; Bulsara, Max

    2013-01-01

    and thus impair cosmesis further, so we objectively evaluated the aesthetic outcome of patients within the TARGIT randomised controlled trial. We have used an objective assessment tool for evaluation of cosmetic outcome. Frontal digital photographs were taken at baseline (before TARGIT or EBRT) and yearly...... in a randomised setting, the aesthetic outcome of patients demonstrates that those treated with TARGIT have a superior cosmetic result to those patients who received conventional external beam radiotherapy....

  18. Dysprosium detector for neutron dosimetry in external beam radiotherapy

    Science.gov (United States)

    Ostinelli, A.; Berlusconi, C.; Conti, V.; Duchini, M.; Gelosa, S.; Guallini, F.; Vallazza, E.; Prest, M.

    2014-09-01

    Radiotherapy treatments with high-energy (>8 MeV) photon beams are a standard procedure in clinical practice, given the skin and near-target volumes sparing effect, the accurate penetration and the uniform spatial dose distribution. On the other hand, despite these advantages, neutrons may be produced via the photo-nuclear (γ,n) reactions of the high-energy photons with the high-Z materials in the accelerator head, in the treatment room and in the patient, resulting in an unwanted dose contribution which is of concern, given its potential to induce secondary cancers, and which has to be monitored. This work presents the design and the test of a portable Dysprosium dosimeter to be used during clinical treatments to estimate the "in vivo" dose to the patient. The dosimeter has been characterized and validated with tissue-equivalent phantom studies with a Varian Clinical iX 18 MV photon beam, before using it with a group of patients treated at the S. Anna Hospital in Como. The working principle of the dosimeter together with the readout chain and the results in terms of delivered dose are presented.

  19. Dysprosium detector for neutron dosimetry in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ostinelli, A.; Berlusconi, C.; Conti, V.; Duchini, M.; Gelosa, S. [Medical Physics - Sant' Anna Hospital, Como (Italy); Guallini, F. [EL.SE s.r.l. (Italy); Vallazza, E. [INFN, Trieste (Italy); Prest, M. [University of Insubria, Como (Italy)

    2014-09-21

    Radiotherapy treatments with high-energy (>8MeV) photon beams are a standard procedure in clinical practice, given the skin and near-target volumes sparing effect, the accurate penetration and the uniform spatial dose distribution. On the other hand, despite these advantages, neutrons may be produced via the photo-nuclear (γ,n) reactions of the high-energy photons with the high-Z materials in the accelerator head, in the treatment room and in the patient, resulting in an unwanted dose contribution which is of concern, given its potential to induce secondary cancers, and which has to be monitored. This work presents the design and the test of a portable Dysprosium dosimeter to be used during clinical treatments to estimate the “in vivo” dose to the patient. The dosimeter has been characterized and validated with tissue-equivalent phantom studies with a Varian Clinical iX 18 MV photon beam, before using it with a group of patients treated at the S. Anna Hospital in Como. The working principle of the dosimeter together with the readout chain and the results in terms of delivered dose are presented.

  20. Oxidative Stress Markers in Prostate Cancer Patients after HDR Brachytherapy Combined with External Beam Radiation

    OpenAIRE

    Alina Woźniak; Rafał Masiak; Michał Szpinda; Celestyna Mila-Kierzenkowska; Bartosz Woźniak; Roman Makarewicz; Anna Szpinda

    2012-01-01

    Assessment of oxidative stress markers was perfomed in prostate cancer (PCa) patients subjected to high-dose brachytherapy (HDR) with external beam radiotherapy (EBRT). Sixty men with PCa were subjected to combined two-fraction treatment with HDR (tot. 20 Gy) and EBRT (46 Gy). Blood samples were taken before treatment, immediately afterwards, after 1.5–3 months, and approx. 2 years. Control group consisted of 30 healthy men. Erythrocyte glutathione peroxidase activity in the patients was lowe...

  1. Comparison Analysis of MR Images Before and After External Beam Radiotherapy in Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun Hye; Baek, Chung Seok; Lee, Sung Yong; Byun, Young Sik [Dept. of Radiation Oncology, Cheil General Hospital, Seoul (Korea, Republic of)

    2011-03-15

    To analyze availability of MR images before and after external beam radiotherapy in brachytherapy, we will acquire MR images before and after external beam radiotherapy and compare the change of direction of uterine cavity and analyze the accuracy of applicator insertion. From January 2009 to December 2010, we compared MR images before and after external beam radiotherapy for uterine cervical cancer only with radical purpose treatment. MR images which was acquired after external beam radiotherapy has done with inserted status of CT/MR applicator. As a consequence, the tumor was markedly reduced after external beam radiotherapy. The change of anteflexion of uterus turned into retroflexion of the uterine cavity was 17.1%. The case of wrong insertion of tandem include direction or length was 14.3%. According to MR images taken after external beam radiotherapy, we recognized not only reduced the tumor volume but the marked change of exact direction or length of the uterine cavity. So the confirmation of accurate insertion based on MR images before brachytherapy could be very helpful for optimal brachytherapy treatment planning with reduced applicator insertion errors.

  2. Intraoperative avidination for radionuclide treatment as a radiotherapy boost in breast cancer: results of a phase II study with {sup 90}Y-labeled biotin

    Energy Technology Data Exchange (ETDEWEB)

    Paganelli, Giovanni; De Cicco, Concetta; Carbone, Giuseppe; Pacifici, Monica [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Ferrari, Mahila E.; Cremonesi, Marta; Di Dia, Amalia [European Institute of Oncology, Division of Medical Physics, Milan (Italy); Pagani, Gianmatteo; Galimberti, Viviana; Luini, Alberto [European Institute of Oncology, Division of Senology, Milan (Italy); Leonardi, Maria Cristina; Ferrari, Annamaria; Orecchia, Roberto [European Institute of Oncology, Division of Radiotherapy, Milan (Italy); De Santis, Rita [Sigma-Tau SpA R and D, Rome (Italy); Zurrida, Stefano [European Institute of Oncology, Division of Senology, Milan (Italy); University of Milan School of Medicine, Milan (Italy); Veronesi, Umberto [European Institute of Oncology, Scientific Director, Milan (Italy)

    2010-02-15

    External beam radiotherapy (EBRT) after conservative surgery for early breast cancer requires 5-7 weeks. For elderly patients and those distant from an RT center, attending for EBRT may be difficult or impossible. We investigated local toxicity, cosmetic outcomes, and quality of life in a new breast irradiation technique - intraoperative avidination for radionuclide therapy (IART) - in which avidin is administered to the tumor bed and {sup 90}Y-labelled biotin later administered intravenously to bind the avidin and provide irradiation. Reduced duration EBRT (40 Gy) is given subsequently. After surgery, 50 (ten patients), 100 (15 patients) or 150 mg (ten patients) of avidin was injected into the tumor bed. After 12-24 h, 3.7 GBq {sup 90}Y-biotin (beta source for therapeutic effect) plus 185 MBq {sup 111}In-biotin (gamma source for imaging and dosimetry) was infused slowly. Whole-body scintigraphy and SPECT/CT images were taken for up to 30 h. Shortened EBRT started 4 weeks later. Local toxicity was assessed by RTOG scale; quality of life was assessed by EORTC QOL-30. Of 35 patients recruited (mean age 63 years; range 42-74) 32 received IART plus EBRT. 100 mg avidin provided 19.5 {+-} 4.0 Gy to the tumor bed and was considered the optimum dose. No side-effects of avidin or {sup 90}Y-biotin occurred, with no hematological or local toxicity. Local G3 toxicity occurred in 3/32 patients during EBRT. IART plus EBRT was well accepted, with good cosmetic outcomes and maintained quality of life. IART plus reduced EBRT can accelerate irradiation after conservative breast surgery. (orig.)

  3. Correlation in Rectal Cancer Between Clinical Tumor Response After Neoadjuvant Radiotherapy and Sphincter or Organ Preservation: 10-Year Results of the Lyon R 96-02 Randomized Trial

    Energy Technology Data Exchange (ETDEWEB)

    Ortholan, Cecile [Department of Radiation Oncology, Antoine Lacassagne Cancer Center, Nice, UNSA (Universite de Nice Sophia-Antipolis) (France); Department of Oncology-Radiotherapy, Hopital Princesse Grace, Monaco (France); Romestaing, Pascale [Hopital Prive Jean Mermoz, Lyon (France); Chapet, Olivier [Department of Radiation Oncology, Lyon Sud University Hospital, Hospices Civils de Lyon, Lyon (France); Gerard, Jean Pierre, E-mail: jean-pierre.gerard@nice.unicancer.fr [Department of Radiation Oncology, Antoine Lacassagne Cancer Center, Nice, UNSA (Universite de Nice Sophia-Antipolis) (France)

    2012-06-01

    Purpose: To investigate, in rectal cancer, the benefit of a neoadjuvant radiation dose escalation with endocavitary contact radiotherapy (CXRT) in addition to external beam radiotherapy (EBRT). This article provides an update of the Lyon R96-02 Phase III trial. Methods and Materials: A total of 88 patients with T2 to T3 carcinoma of the lower rectum were randomly assigned to neoadjuvant EBRT 39 Gy in 13 fractions (43 patients) vs. the same EBRT with CXRT boost, 85 Gy in three fractions (45 patients). Median follow-up was 132 months. Results: The 10-year cumulated rate of permanent colostomy (CRPC) was 63% in the EBRT group vs. 29% in the EBRT+CXRT group (p < 0.001). The 10-year rate of local recurrence was 15% vs. 10% (p = 0.69); 10-year disease-free survival was 54% vs. 53% (p = 0.99); and 10-year overall survival was 56% vs. 55% (p = 0.85). Data of clinical response (CR) were available for 78 patients (36 in the EBRT group and 42 in the EBRT+CXRT group): 12 patients were in complete CR (1 patient vs. 11 patients), 53 patients had a CR {>=}50% (24 patients vs. 29 patients), and 13 patients had a CR <50% (11 patients vs. 2 patients) (p < 0.001). Of the 65 patients with CR {>=}50%, 9 had an organ preservation procedure (meaning no rectal resection) taking advantage of major CR. The 10-year CRPC was 17% for patients with complete CR, 42% for patients with CR {>=}50%, and 77% for patients with CR <50% (p = 0.014). Conclusion: In cancer of the lower rectum, CXRT increases the complete CR, turning in a significantly higher rate of long-term permanent sphincter and organ preservation.

  4. Salivary Gland. Photon beam and particle radiotherapy: Present and future.

    Science.gov (United States)

    Orlandi, Ester; Iacovelli, Nicola Alessandro; Bonora, Maria; Cavallo, Anna; Fossati, Piero

    2016-09-01

    Salivary gland cancers (SGCs) are rare diseases and their treatment depends upon histology, stage and site of origin. Radical surgery is the mainstay of treatment but radiotherapy (RT) plays a key role in both the postoperative and the inoperable setting, as well as in recurrent disease. In the absence of prospective randomized trials, a wide retrospective literature suggests postoperative RT (PORT) in patients with high risk pathological features. SGCs, and adenoid cystic carcinoma (ACC) in particular, are known to be radio-resistant tumors and should therefore respond well to particle beam therapy. Recently, excellent outcome has been reported with radical carbon ion RT (CIRT) in particular for ACC. Both modern photon- and hadron-based treatments are effective and are characterized by a favourable toxicity profile. But it is not clear whether one modality is superior to the other for disease control, due to the differences in patients' selection, techniques, fractionation schedules and outcome measurements among clinical experiences. In this paper, we review the role of photon and particle RT for malignant SGCs, discussing the difference between modalities in terms of biological and technical characteristics. RT dose and target volumes for different histologies (ACC versus non-ACC) have also been taken into consideration.

  5. Patient-reported lower urinary tract symptoms, urinary incontinence, and quality of life after external beam radiotherapy for localized prostate cancer - 15 years' follow-up. A comparison with age-matched controls

    Energy Technology Data Exchange (ETDEWEB)

    Fransson, Per (Dept. of Radiation Sciences, Oncology, Umeaa Univ., Umeaa (Sweden))

    2008-06-15

    Background. To prospectively examine the urinary toxicity and quality of life (QOL) in patients 15 years after external beam radiotherapy (EBRT) for localized prostate cancer (LPC) and compare the outcomes with results for age-matched controls. Material and methods. Urinary symptoms were assessed using the symptom-specific Prostate Cancer Symptom Scale (PCSS) questionnaire, and QOL was assessed with the European Organization for Research and Treatment of Cancer (EORTC)'s Quality of Life Questionnaire (QLQ-C30). Both questionnaires were sent to the surviving 41 patients (25%) and the PCSS questionnaire was sent to 69 age-matched controls for comparison. Results. The response rate was 71% in the patient group and 59% in the control group. Two patients and four controls were excluded due to other cancer diagnoses, resulting in a total of 27 patients and 37 controls for inclusion in the analyses. The mean age in both groups was 78 years. In the patient group, incontinence had increased between the 8-year (mean=0.6) and the 15-year follow-up (mean=2.1; p=0.038). No other differences in urinary problems were seen between these two follow-ups. Increased incontinence, stress incontinence, and pain while urinating were reported by the patients in comparison with the controls at 15 years. Role function was worse in the patient group (mean=67.3) compared with the controls (mean=82.4; p=0.046). The patients also reported more appetite loss, diarrhea, nausea/vomiting, and pain than the controls. Conclusion. EBRT for LPC has divergent effects on urinary symptoms and QOL in comparison with age-matched controls. In our patient population, urinary incontinence increased between 8 and 15 years of follow-up. Otherwise, no differences in urinary symptoms were seen between 4 and 15 years. Incontinence, stress incontinence, and pain while urinating were increased after EBRT in comparison with the controls. Conventional EBRT did not result in a major deterioration in QOL 15 years

  6. The relationship between the biochemical control outcomes and the quality of planning of high-dose rate brachytherapy as a boost to external beam radiotherapy for locally and locally advanced prostate cancer using the RTOG-ASTRO Phoenix definition

    Directory of Open Access Journals (Sweden)

    Antonio Cassio Assis Pellizzon, João Salvajoli, Paulo Novaes, Maria Maia, Ricardo Fogaroli, Doglas Gides, Rodrigues Horriot

    2008-01-01

    Full Text Available Purpose: To evaluated prognostic factors and impact of the quality of planning of high dose rate brachytherapy (HDR-BT for patients with local or locally advanced prostate cancer treated with external beam radiotherapy (EBRT and HDR-BT. Methods and Materials: Between 1997 and 2005, 209 patients with biopsy proven prostate adenocarcinoma were treated with localized EBRT and HDR-BT at the Department of Radiation-Oncology, Hospital A. C. Camargo, Sao Paulo, Brazil. Patient's age, Gleason score (GS, clinical stage (CS, initial PSA (iPSA, risk group for biochemical failure (GR, doses of EBRT and HDR-BT, use of three-dimensional planning for HDR-BT (3DHDR and the Biological Effective Dose (BED were evaluated as prognostic factors for biochemical control (bC. Results: Median age and median follow-up time were 68 and 5.3 years, respectively. Median EBRT and HDR-BT doses were 45 Gy and 20 Gy. The crude bC at 3.3 year was 94.2%. For the Low, intermediate and high risk patients the bC rates at 3.3 years were 91.5%, 90.2% and 88.5%, respectively. Overall survival (OS and disease specific survival rates at 3.3 years were 97.8% and 98.4%, respectively. On univariate analysis the prognostic factors related bC were GR (p= 0.040, GS ≤ 6 (p= 0.002, total dose of HDR-BT ≥ 20 Gy (p< 0.001, 3DHDR (p< 0.001, BED-HDR ≥ 99 Gy1.5 (p<0.001 and BED-TT ≥ 185 (p<0.001. On multivariate analysis the statistical significant predictive factors related to bC were RG (p< 0.001, HDR-BT ≥ 20 Gy (p=0.008 and 3DHDR (p<0.001. Conclusions: we observed that the bC rates correlates with the generally accepted risk factors described in the literature. Dose escalation, evaluated through the BED, and the quality of planning of HDR-BT are also important predictive factors when treating prostate cancer.

  7. Targeted intraoperative radiotherapy tumour bed boost during breast-conserving surgery after neoadjuvant chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kolberg, Hans-Christian; Akpolat-Basci, Leyla; Stephanou, Miltiades [Marienhospital Bottrop gGmbH, Department of Gynecology and Obstetrics, Bottrop (Germany); Loevey, Gyoergy [BORAD, Bottrop (Germany); Fasching, Peter A. [University of Erlangen, Erlangen (Germany); Untch, Michael [Helios Klinikum Berlin-Buch, Berlin (Germany); Liedtke, Cornelia [University Hospital Schleswig-Holstein/Campus Luebeck, Luebeck (Germany); Bulsara, Max [University of Notre Dame, Fremantle (Australia); University College, London (United Kingdom); Vaidya, Jayant S. [University College, London (United Kingdom)

    2017-01-15

    The use of targeted intraoperative radiotherapy (TARGIT-IORT) as a tumour bed boost during breast-conserving surgery (BCS) for breast cancer has been reported since 1998. We present its use in patients undergoing breast conservation following neoadjuvant therapy (NACT). In this retrospective study involving 116 patients after NACT we compared outcomes of 61 patients who received a tumour bed boost with IORT during lumpectomy versus 55 patients treated in the previous 13 months with external (EBRT) boost. All patients received whole breast radiotherapy. Local recurrence-free survival (LRFS), disease-free survival (DFS), distant disease-free survival (DDFS), breast cancer mortality (BCM), non-breast cancer mortality (NBCM) and overall mortality (OS) were compared. Median follow up was 49 months. The differences in LRFS, DFS and BCM were not statistically significant. The 5-year Kaplan-Meier estimate of OS was significantly better by 15% with IORT: IORT 2 events (96.7%, 95%CI 87.5-99.2), EBRT 9 events (81.7%, 95%CI 67.6-90.1), hazard ratio (HR) 0.19 (0.04-0.87), log rank p = 0.016, mainly due to a reduction of 10.1% in NBCM: IORT 100%, EBRT 89.9% (77.3-95.7), HR (not calculable), log rank p = 0.015. The DDFS was as follows: IORT 3 events (95.1%, 85.5-98.4), EBRT 12 events (69.0%, 49.1-82.4), HR 0.23 (0.06-0.80), log rank p = 0.012. IORT during lumpectomy after neoadjuvant chemotherapy as a tumour bed boost appears to give results that are not worse than external beam radiotherapy boost. These data give further support to the inclusion of such patients in the TARGIT-B (boost) randomised trial that is testing whether IORT boost is superior to EBRT boost. (orig.) [German] Die intraoperative Radiotherapie (TARGIT-IORT) als vorgezogener Boost im Rahmen der brusterhaltenden Therapie (BET) ist seit 1998 Gegenstand der wissenschaftlichen Diskussion. Wir praesentieren Daten zum Einsatz der IORT bei der BET nach neoadjuvanter Therapie (NACT). In diese retrospektive Analyse

  8. Clinical contribution of the radiotherapy guided by cone-shaped beam tomodensitometry; Apports cliniques de la radiotherapie guidee par tomodensitometrie a faisceau conique

    Energy Technology Data Exchange (ETDEWEB)

    Notter, M.; Yanes, B.; Germond, J.F. [Hopital Neuchatelois, Service de Radiotherapie, La Chaux-de-Fonds (France)

    2006-11-15

    The tomodensitometry with a cone-shaped beam gives a correct position of the rectum and bladder during prostate or pelvis irradiation and allows to follow the evolution of the tumor regression. Combined to the three dimensional conformational irradiation, the image guided radiotherapy (I.G.R.T.) aims to increase the efficiency of the radiotherapy. (N.C.)

  9. Value of Fused 18F-Choline-PET/MRI to Evaluate Prostate Cancer Relapse in Patients Showing Biochemical Recurrence after EBRT: Preliminary Results

    Directory of Open Access Journals (Sweden)

    Arnoldo Piccardo

    2014-01-01

    Full Text Available Purpose. We compared the accuracy of 18F-Choline-PET/MRI with that of multiparametric MRI (mMRI, 18F-Choline-PET/CT, 18F-Fluoride-PET/CT, and contrast-enhanced CT (CeCT in detecting relapse in patients with suspected relapse of prostate cancer (PC after external beam radiotherapy (EBRT. We assessed the association between standard uptake value (SUV and apparent diffusion coefficient (ADC. Methods. We evaluated 21 patients with biochemical relapse after EBRT. Patients underwent 18F-Choline-PET/contrast-enhanced (CeCT, 18F-Fluoride-PET/CT, and mMRI. Imaging coregistration of PET and mMRI was performed. Results. 18F-Choline-PET/MRI was positive in 18/21 patients, with a detection rate (DR of 86%. DRs of 18F-Choline-PET/CT, CeCT, and mMRI were 76%, 43%, and 81%, respectively. In terms of DR the only significant difference was between 18F-Choline-PET/MRI and CeCT. On lesion-based analysis, the accuracy of 18F-Choline-PET/MRI, 18F-Choline-PET/CT, CeCT, and mMRI was 99%, 95%, 70%, and 85%, respectively. Accuracy, sensitivity, and NPV of 18F-Choline-PET/MRI were significantly higher than those of both mMRI and CeCT. On whole-body assessment of bone metastases, the sensitivity of 18F-Choline-PET/CT and 18F-Fluoride-PET/CT was significantly higher than that of CeCT. Regarding local and lymph node relapse, we found a significant inverse correlation between ADC and SUV-max. Conclusion. 18F-Choline-PET/MRI is a promising technique in detecting PC relapse.

  10. Radiotherapy combined with hormonal therapy in prostate cancer: the state of the art

    Directory of Open Access Journals (Sweden)

    Piotr Milecki

    2010-10-01

    Full Text Available Piotr Milecki1,2, Piotr Martenka1, Andrzej Antczak3, Zbigniew Kwias31Department of Radiotherapy, Greater Poland Cancer Center, Poznan, Poland; 2Department of Electroradiology, Medical University, Poznan, Poland; 3Chair of Urology, Medical University, Poznan, PolandAbstract: Androgen-deprivation therapy (ADT is used routinely in combination with definitive external beam radiation therapy (EBRT in patients with high-risk clinically localized or locally advanced disease. The combined treatment (ADT–EBRT also seems to play a significant role in improving treatment results in the intermediate-risk group of prostate cancer patients. On the other hand, there is a growing body of evidence that treatment with ADT can be associated with serious and lifelong adverse events including osteoporosis, cardiovascular disease, diabetes, and many others. Almost all ADT adverse events are time dependant and tend to increase in severity with prolongation of hormonal manipulation. Therefore, it is crucial to clearly state the optimal schedule for ADT in combination with EBRT, that maintaining the positive effect on treatment efficacy would keep the adverse events risk at reasonable level. To achieve this goal, treatment schedule may have to be highly individualized on the basis of the patient-specific potential vulnerability to adverse events. In this study, the concise and evidence-based review of current literature concerning the general rationales for combining radiotherapy and hormonal therapy, its mechanism, treatment results, and toxicity profile is presented.Keywords: prostate cancer, radiotherapy, androgen deprivation, combined treatment

  11. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

    Science.gov (United States)

    Christensen, A. N.; Rydhög, J. S.; Søndergaard, R. V.; Andresen, T. L.; Holm, S.; Munck Af Rosenschöld, P.; Conradsen, K.; Jølck, R. I.

    2016-05-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively.Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The

  12. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

    DEFF Research Database (Denmark)

    Christensen, Anders Nymark; Rydhög, J. S.; Søndergaard, Rikke Vicki;

    2016-01-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver......-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive (106)Ag......, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy...

  13. Intraoperative Radiotherapy for Pancreatic Cancer: 30-Year Experience in a Single Institution in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Jingu, Keiichi, E-mail: kjingu-jr@rad.med.tohoku.ac.jp [Department of Radiation Oncology, Tohoku University School of Medicine, Sendai (Japan); Tanabe, Takaya [Department of Radiation Oncology, Tohoku University School of Medicine, Sendai (Japan); Nemoto, Kenji [Department of Radiation Oncology, Yamagata University School of Medicine, Yamagata (Japan); Ariga, Hisanori; Umezawa, Rei; Ogawa, Yoshihiro; Takeda, Ken; Koto, Masashi; Sugawara, Toshiyuki; Kubozono, Masaki; Shimizu, Eiji; Abe, Keiko; Yamada, Shogo [Department of Radiation Oncology, Tohoku University School of Medicine, Sendai (Japan)

    2012-07-15

    Purpose: To analyze retrospectively the results of intraoperative radiotherapy (IORT) with or without external beam radiotherapy ({+-} EBRT) for localized pancreatic cancer in the past three decades and to analyze prognostic factors by multivariate analysis. Methods and Materials: Records for 322 patients with pancreatic cancer treated by IORT {+-} EBRT in Tohoku University Hospital between 1980 and 2009 were reviewed. One hundred ninety-two patients who had no distant organ metastases or dissemination at the time of laparotomy were enrolled in the present study. Results: Eighty-three patients underwent gross total resection (R0: 48 patients, R1: 35 patients), and 109 patients underwent only biopsy or palliative resection. Fifty-five patients underwent adjuvant EBRT, and 124 underwent adjuvant chemotherapy. The median doses of IORT and EBRT were 25 and 40 Gy, respectively. The median follow-up period was 37.5 months. At the time of the analysis, 166 patients had disease recurrence, and 35 patients had local failure. The 2-year local control (LC) and overall survival (OS) rates were 71.0% and 16.9%, respectively. Comparison of the results for each decade showed that OS was significantly improved decade by decade (2-year: 25.0% vs. 18.8% vs. 4.2%, p < 0.001). Multivariate analysis showed that degree of resection (R0-1 vs. R2, hazard ratio = 1.97, p = 0.001) and adjuvant chemotherapy (yes vs. no, hazard ratio = 1.54, p = 0.028) had significant impacts on OS. Late gastrointestinal morbidity of Common Terminology Criteria for Adverse Events version 3.0 grade 4 or 5 was observed in four patients. Conclusion: Excellent local control for pancreatic cancer with few cases of severe late toxicity was achieved by using IORT. OS of patients with pancreatic cancer treated by IORT {+-} EBRT improved significantly decade by decade. Multivariate analysis showed that degree of resection and adjuvant chemotherapy had significant impacts on OS.

  14. Radiotherapy

    Directory of Open Access Journals (Sweden)

    Rema Jyothirmayi

    1999-01-01

    Full Text Available Purpose. Conservative treatment in the form of limited surgery and post-operative radiotherapy is controversial in hand and foot sarcomas, both due to poor radiation tolerance of the palm and sole, and due to technical difficulties in achieving adequate margins.This paper describes the local control and survival of 41 patients with soft tissue sarcoma of the hand or foot treated with conservative surgery and radiotherapy. The acute and late toxicity of megavoltage radiotherapy to the hand and foot are described. The technical issues and details of treatment delivery are discussed. The factors influencing local control after radiotherapy are analysed.

  15. Stereotactic radiotherapy for spinal intradural metastases developing within or adjacent to the previous irradiation field--report of three cases.

    Science.gov (United States)

    Mori, Yoshimasa; Hashizume, Chisa; Shibamoto, Yuta; Kobayashi, Tatsuya; Nakazawa, Hisato; Hagiwara, Masahiro; Tsugawa, Takahiko

    2013-08-01

    Results of stereotactic radiotherapy (SRT) for spinal intradural metastases developing inside or adjacent to the previous external-beam radiation therapy (EBRT) field are shown in 3 cases. One case of spinal intramedullary metastasis and two cases of intradural extramedullary metastases were treated using a Novalis shaped-beam SRT. Case 1 developed an intramedullary metastatic tumor in the C1 spinal medulla inside the previous whole brain EBRT field and another lesion adjacent to the field in the C2 spinal medulla. Case 2 developed intradural extramedullary metastasis around C6-8 inside the previous EBRT field for the primary lung adenocarcinoma. Case 3 developed multiple spinal intradural extramedullary metastatic deposits after surgical resection and following whole brain EBRT for brain metastasis. We delivered 24 to 36 Gy in 5 to 12 fractions. The treated tumors were stable or decreased in size until the patients' death from the primary cancer (10, 22, and 5 months). Neurological symptoms were stable or improved in all 3 patients. Palliative SRT using Novalis is expected to be safe and effective even if the patient develops spinal intradural metastases within or adjacent to the previous irradiation field.

  16. Efficient and accurate stereotactic radiotherapy using flattening filter free beams and HexaPOD robotic tables

    DEFF Research Database (Denmark)

    Nielsen, Morten; Hansen, C. R.; Brink, C.

    2016-01-01

    Flattening filter free (FFF) high dose rate beam technique was introduced for brain stereotactic radiosurgery (SRS) and lung Stereotactic Body Radiotherapy (SBRT). Furthermore, a HexaPOD treatment table was introduced for the brain SRS to enable correction of rotational setup errors. 19 filter fl...

  17. Assessment of radiotherapy photon beams: A practical and low cost methodology

    Science.gov (United States)

    Reis, C. Q. M.; Nicolucci, P.

    2017-02-01

    Dosimetric properties of radiation beams used in radiotherapy are directly related to the energy spectrum produced by the treatment unit. Therefore, the development of methodologies to evaluate in a simple and accurate way the spectra of clinical beams can help establishing the quality control of the treatment. The purpose of this study is to present a practical and low cost methodology for determining primary spectra of radiotherapy photon beams from transmission measurements in attenuators of aluminum and using the method of the inverse Laplace transform. Monte Carlo simulation with PENELOPE code was used in order to evaluate and validate the reconstructed spectra by the calculation of dosimetric parameters that characterize the beam. Percentage depth dose values simulated with a 6 MV reconstructed spectrum shows maximum difference of 4.4% when compared to values measured at the corresponding clinical beam. For a 10 MV beam that difference was around 4.2%. Results obtained in this study confirm the adequacy of the proposed methodology for assessing primary photon beams produced by clinical accelerators.

  18. Volumetric modulation arc radiotherapy with flattening filter-free beams compared with conventional beams for nasopharyngeal carcinoma: a feasibility study

    Institute of Scientific and Technical Information of China (English)

    Mingzan Zhuang; Tuodan Zhang; Zhijian Chen; Zhixiong Lin; Derui Li; Xun Peng; Qingchun Qiu

    2013-01-01

    There is increasing interest in the clinical use of flattening filter-free (FFF) beams.In this study,we aimed to investigate the dosimetric characteristics of volumetric modulated arc radiotherapy (VMAT) with FFF beams for nasopharyngeal carcinoma (NPC).Ten NPC patients were randomly selected to undergo a RapidArc plan with either FFF beams (RA-FFF) or conventional beams (RA-C).The doses to the planning target volumes (PTVs),organs at risk (OARs),and normal tissues were compared.The technical delivery parameters for RapidArc plans were also assessed to compare the characteristics of FFF and conventional beams.Both techniques delivered adequate doses to PTVs.For PTVs,RA-C delivered lower maximum and mean doses and improved conformity and homogeneity compared with RA-FFF.Both techniques provided similar maximum doses to the optic nerves and lenses.For the brain stem,spinal cord,larynx,parotid glands,oral cavity,and skin,RA-FFF showed significant dose increases compared to RA-C.The dose to normal tissue was lower in RA-FFF.The monitor units (MUs) were (536 ± 46) MU for RA-FFF and (501 ± 25) MU for RA-C.The treatment duration did not significantly differ between plans.Although both treatment plans could meet clinical needs,RA-C is dosimetrically superior to RA-FFF for NPC radiotherapy.

  19. Internal hemipelvectomy with intraoperative and external beam radiotherapy in the limb-sparing treatment of a pelvic girdle chondrosarcoma

    NARCIS (Netherlands)

    Hoekstra, HJ; Szabo, BG

    1998-01-01

    The case of a patient with an extensive pelvic girdle chondrosarcoma treated with internal hemipelvectomy and intraoperative radiotherapy, followed by adjuvant high-dose external beam radiotherapy, with a successful attempt in achieving long-term local tumor control and limb-sparing treatment is des

  20. Optimizing the TLD-100 readout system for various radiotherapy beam doses using the Taguchi methodology

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.Y. [School of Medical Imaging Technology, Chung Shan Medical University, Taichung 402, Taiwan (China); Liu, K.C.; Chen, H.H. [Graduate Institute of Radiological Science, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan (China); Pan, L.K. [Graduate Institute of Radiological Science, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan (China)], E-mail: lkpan@ctust.edu.tw

    2010-03-15

    The TLD-100 readout system was optimized for various radiotherapy beam doses using the Taguchi method. The radiotherapy beam was produced by a Varian 21EX linear accelerator (LINAC) at 6 MV. The beam doses were 50, 100 and 150 cGy, and the measured data in each group were averaged from three TLD-100 chips. A total of nine combinations of four parameters were arranged, in the manner suggested by Taguchi. The four parameters were defined as initial temperature, heating rate, preheat time and maximum set temperature of the readout system during TLD reading. The loss function {eta} adopted herein was specifically defined to satisfy the requirements of both sharp linearity and good reproducibility of the TLD reading at various radiotherapy beam doses. The optimized values were: (1) 50 deg. C for initial temperature, (2) 3 deg. C/s for heating rate, (3) 5 min for the TLD preheat time and (4) 250 deg. C for the maximum temperature for TLD reading. Additionally, the parameters that dominated the TLD readout were: (1) initial temperature, (2) heating rate and (4) maximum temperature setting for TLD reading; and the minor parameter was (3) TLD preheat time before reading. The interactions among the dominant parameters were also studied: no significant cross interaction occurred between initial temperature and heating rate or between initial temperature and maximum temperature. However, a complex cross-interaction existed between optimal heating rate and maximum temperature.

  1. Facilities for radiotherapy with ion beams status and worldwide developments

    CERN Document Server

    Wolf, B H

    1999-01-01

    Forty-five years after the first ion beam therapy in Berkeley around 25,000 cancer patients worldwide have been treated successfully. Ion accelerators, designed for nuclear research, delivered most of this treatment. The first hospital-based facility started operation in 1998 at Loma Linda California, the first for heavier ions at Chiba, Japan in 1994 and the first commercially delivered facilities started operation in 1998 at Kashiwa, Japan. In 2000, the Harvard Medical Centre, Boston, US, will commence operation and several new facilities are planned or under construction worldwide, although none in Australia. This paper will discuss the physical and biological advantages of ion beams over x-rays and electrons. In the treatment of cancer patients ion beam therapy is especially suited for localised tumours in radiation sensitive areas like skull or spine. Heavier ions are also effective in anoxic tumour cells (found around the normally oxygenated cell population). An additional advantage of the heavier carbo...

  2. A dose optimization method for electron radiotherapy using randomized aperture beams.

    Science.gov (United States)

    Engel, Konrad; Gauer, Tobias

    2009-09-01

    The present paper describes the entire optimization process of creating a radiotherapy treatment plan for advanced electron irradiation. Special emphasis is devoted to the selection of beam incidence angles and beam energies as well as to the choice of appropriate subfields generated by a refined version of intensity segmentation and a novel random aperture approach. The algorithms have been implemented in a stand-alone programme using dose calculations from a commercial treatment planning system. For this study, the treatment planning system Pinnacle from Philips has been used and connected to the optimization programme using an ASCII interface. Dose calculations in Pinnacle were performed by Monte Carlo simulations for a remote-controlled electron multileaf collimator (MLC) from Euromechanics. As a result, treatment plans for breast cancer patients could be significantly improved when using randomly generated aperture beams. The combination of beams generated through segmentation and randomization achieved the best results in terms of target coverage and sparing of critical organs. The treatment plans could be further improved by use of a field reduction treatment plans could be further improved by use of a field reduction algorithm. Without a relevant loss in dose distribution, the total number of MLC fields and monitor units could be reduced by up to 20%. In conclusion, using randomized aperture beams is a promising new approach in radiotherapy and exhibits potential for further improvements in dose optimization through a combination of randomized electron and photon aperture beams.

  3. The magic cube and the pixel ionization chamber: detectors for monitor and dosimetry of radiotherapy beams

    Science.gov (United States)

    Amerio, S.; Boriano, A.; Bourhaleb, F.; Cirio, R.; Donetti, M.; Garelli, E.; Giordanengo, S.; Madon, E.; Marchetto, F.; Nastasi, U.; Peroni, C.; Sanz Freire, C. J.; Sardo, A.; Trevisiol, E.

    2003-09-01

    Tumor therapy takes advantage of the energy deposition of radiation to concentrate high doses in the target while sparing healthy tissue. Elective pathologies for highly conformal radiotherapies such as photon Intensity Modulated Radiotherapy (IMRT) and radiotherapy with hadrons are head and neck, eye, prostate and in general all tumors that are either deep or located close to critical organs. In the world there are several centers that are using such techniques and a common problem that is being experienced is the verification of treatment plans and monitoring of the beam. We have designed and built two detectors that allow 2D and 3D measurements of dose and fluence of such beams. The detectors allow measurements on big surfaces, up to 25∗25 cm2. The active media are parallel plate, strip and pixel segmented ionization chambers with front-end Very Large Scale Integration (VLSI) readout and PC based data acquistion. The description of dosimeter, chamber and electronics will be given with results from beam tests and therapy plan verification.

  4. The magic cube and the pixel ionization chamber: detectors for monitor and dosimetry of radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Amerio, S.; Boriano, A.; Bourhaleb, F.; Cirio, R.; Donetti, M.; Garelli, E.; Giordanengo, S.; Madon, E.; Marchetto, F.; Nastasi, U.; Peroni, C.; Sanz Freire, C.J.; Sardo, A.; Trevisiol, E

    2003-09-01

    Tumor therapy takes advantage of the energy deposition of radiation to concentrate high doses in the target while sparing healthy tissue. Elective pathologies for highly conformal radiotherapies such as photon Intensity Modulated Radiotherapy (IMRT) and radiotherapy with hadrons are head and neck, eye, prostate and in general all tumors that are either deep or located close to critical organs. In the world there are several centers that are using such techniques and a common problem that is being experienced is the verification of treatment plans and monitoring of the beam. We have designed and built two detectors that allow 2D and 3D measurements of dose and fluence of such beams. The detectors allow measurements on big surfaces, up to 25*25 cm{sup 2}. The active media are parallel plate, strip and pixel segmented ionization chambers with front-end Very Large Scale Integration (VLSI) readout and PC based data acquistion. The description of dosimeter, chamber and electronics will be given with results from beam tests and therapy plan verification.

  5. A quality audit program for external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, W.F.; Stovall, M. [Univ. of Texas, Houston, TX (United States)

    1993-12-31

    For more than 25 years, the University of Texas M. D. Anderson Cancer Center has had a quality audit program using mailed dosimeters to verify radiation therapy machine output. Two programs, one compulsory and one voluntary, presently monitor therapy beams at more than 1000 megavoltage-therapy facilities. A successful program requires two major components: a high-precision thermoluminescent dosimeter (TLD) system and dedicated staff that interact closely with the users to resolve discrepancies. The TLD system, the logistics used, and the human interaction of these programs are described. Examples show that the programs can identify major discrepancies, exceeding 5 %, as well as discrepancies as small as 3%.

  6. Is there a role for an external beam boost in cervical cancer radiotherapy?

    Directory of Open Access Journals (Sweden)

    Rajni A. Sethi

    2013-01-01

    Full Text Available AbstractObjectives: Some patients are medically unfit for or averse to undergoing a brachytherapy boost as part of cervical cancer radiotherapy. In order to be able to definitively treat these patients, we assessed whether we could achieve a boost plan that would mimic our brachytherapy plans using external beam radiotherapy.Methods: High dose rate brachytherapy plans of 20 patients with stage IIB cervical cancer treated with definitive chemoradiotherapy were included in this study. Patients had undergone CT simulations with tandem and ovoids in place. Point A dose was 600-700 cGy. We attempted to replicate the boost dose distribution from brachytherapy plans using intensity-modulated radiotherapy (IMRT, Varian Medical Systems, Palo Alto, CA, volumetric modulated arc therapy (VMAT, Rapid Arc, Varian Medical Systems, Palo Alto, CA, or TomoTherapy (Accuray, Inc., Sunnyvale, CA with the brachytherapy 100% isodose line as our target. Target coverage, normal tissue dose, and brachytherapy point doses were compared with ANOVA. Two-sided p-values ≤ 0.05 were considered significant.Results: External beam plans had excellent PTV coverage, with no difference in mean PTV V95% among planning techniques (range 98 – 100%. External beam plans had lower bladder Dmax, small intestine Dmax, and vaginal mucosal point dose than brachytherapy plans, with no difference in bladder point dose, mean bladder dose, mean small intestine dose, or rectal dose. Femoral head dose, parametria point dose, and pelvic sidewall point dose were higher with external beam techniques than brachytherapy. Conclusions: External beam plans had comparable target coverage and potential for improved sparing of most normal tissues compared to tandem and ovoid brachytherapy.

  7. The Outcome of Conventional External Beam Radiotherapy for Patients with Squamous Cell Carcinoma of the Esophagus

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Ji Young [Chosun University College of Medicine, Gwangju (Korea, Republic of)

    2008-03-15

    The best treatment for advanced esophageal cancer is chemoradiotherapy followed by surgery. In spite of the advance of multimodality therapy, most patients with esophageal cancer are treated with radiation therapy alone. This study reports the outcome of the use of conventional external beam radiotherapy alone for the treatment of esophageal cancer. Between January 1998 and December 2005, 30 patients with squamous cell carcinoma of the esophagus were treated with external beam radiotherapy using a total dose exceeding 40 Gy. Radiotherapy was delivered with a total dose of 44-60 Gy (median dose, 57.2 Gy) over 36 {approx}115 days (median time, 45 days). Thirteen patients (43.3%) had a history of disorders such as diabetes, hypertension, tuberculosis, lye stricture, asthma, cerebral infarct, and cancers. Four patients metachronously had double primary cancers. The most common location of a tumor was the mid-thoracic portion of the esophagus (56.7%). Tumor lengths ranged from 2 cm to 11 cm, with a median length of 6 cm. For AJCC staging, stage III was the most common (63.3%). Five patients had metastases at diagnosis. The median overall survival was 8.3 months. The survival rates at 1-year and 2-years were 33.3% and 18.7%, respectively. The complete response rate 1{approx}3 months after radiotherapy was 20% (6/30) and the partial response rate was 70% (21/30). Sixteen patients (53.3%) had an improved symptom of dysphagia. Significant prognostic factors were age, tumor length, stage, degree of dysphagia at the time of diagnosis and tumor response. Cox regression analysis revealed the aim of treatment, clinical tumor response and tumor length as independent prognostic factors for overall survival. Twenty-eight patients had local failure and another four patients had metastases. Three patients were detected with double primary cancers in this analysis. A complication of esophageal stricture was observed in three patients (10%), and radiation pneumonitis occurred in two

  8. Electron contamination in 4 MV and 10 MV radiotherapy x-ray beams.

    Science.gov (United States)

    Harper, N R; Metcalfe, P E; Hoban, P W; Round, W H

    1991-09-01

    A thin window parallel-plate ionization chamber was constructed for dose measurement in the build-up region of high energy radiotherapy photon beams. The chamber is an integral part of a perspex block. The entrance window is 12 microns Melinex foil with a thin aluminium surface. Cavity thickness is 1.45 mm. Surface doses for varying field sizes were found to increase almost linearly with the side length of a square field. The surface dose for a 10x10 cm 4 MV photon beam is 12.1% for an open field and this increases to 14.1% with a polycarbonate block tray in the beam. Similarly for a 10 MV photon beam the surface dose is 10.6% for an open field and this increases to 12.4% with a polycarbonate block tray. The difference between the dose for an open field and a field with a polycarbonate block tray inserted becomes more significant for larger field sizes. Electron contamination depth dose curves are determined for a 4 MV and 10 MV photon beam. This is achieved by subtracting a pure photon beam build-up curve generated by an EGS4 Monte Carlo simulation from the experimental build-up curve. The EGS4 curve is a theoretical, electron contamination free curve. The electron contamination curve (of the 10 MV photon beam) has depth dose characteristics similar to that of a broad low energy electron beam.

  9. Nanoscale radiation transport and clinical beam modeling for gold nanoparticle dose enhanced radiotherapy (GNPT) using X-rays.

    Science.gov (United States)

    Zygmanski, Piotr; Sajo, Erno

    2016-01-01

    We review radiation transport and clinical beam modelling for gold nanoparticle dose-enhanced radiotherapy using X-rays. We focus on the nanoscale radiation transport and its relation to macroscopic dosimetry for monoenergetic and clinical beams. Among other aspects, we discuss Monte Carlo and deterministic methods and their applications to predicting dose enhancement using various metrics.

  10. Differentiated Thyroid Cancer with Extrathyroidal Extension: Prognosis and the Role of External Beam Radiotherapy

    Directory of Open Access Journals (Sweden)

    Michael A. Sia

    2010-01-01

    Full Text Available A study was performed to identify variables that affected cause-specific survival (CSS and local relapse-free rate (LRFR in patients with differentiated thyroid cancer (DTC and extrathyroid extension (ETE and to examine the role of external beam radiotherapy (XRT. Prognostic factors were similar to those found in studies of all patients with DTC. In patients with postoperative gross residual disease treated with radiotherapy, 10-year CSS and LRFR were 48% and 90%. For patients with no residual or microscopic disease, 10-year CSS and LRFR were 92% and 93%. In patients older than 60 years with T3 ETE but no gross residual disease postoperatively there was an improved LRFR at 5 years of 96%, compared to 87.5% without XRT (P=.02. Patients with gross ETE benefit from XRT and there may be a potential benefit in reducing locoregional failure in patients over 60 years with minimal extrathyroidal extension (T3.

  11. Radiotherapy by particle beams (hadrontherapy) of intracranial tumours: a survey on pathology.

    Science.gov (United States)

    Schiffer, D

    2005-04-01

    A review of the principal contributions of radio-therapy of brain tumours by beam particles is carried out. Neutrons, protons and light ions are considered along with their pros and cons in relation to types and locations of brain tumours. A particular emphasis is given to the pathologic studies of their effects directly o n tumours and on the normal nervous tissue, considering mainly the relevant action mechanisms of the radiation types and the requirements of the clinical therapeutic strategies. For comparison the main features of the pathologic effects of radiotherapy by photons are described. From the review it emerges that the new modality of radiation by protons and light ions, because of their peculiar physical characteristics, may represent a new way of destroying the tumour and sparing normal nervous tissue, especially when deeply located and irregularly shaped tumours are concerned. More neuropathological studies are needed in order to better understand the potentiality of the new treatment of modalities.

  12. Development of a postal dosimetric system for quality assurance programs in radiotherapy using fotons beams in non references conditions

    CERN Document Server

    Marin, A

    2003-01-01

    In radiotherapy, to cure the primary tumor, the absorbed dose delivered at the target volume should have an accuracy better than +- 5%. As the basic aim in radiotherapy is the eradication of the primary tumor with the smallest possible damage to the health tissues, it is necessary to guarantee that the dose delivered to the patient in different depths and treatment configurations has the right accuracy. For this reason, a quality control program should be carried out by regulatory and national standardization programs including postal evaluation of the beam dosimetry are also necessary. Since many years Brazil is running a postal quality control program in radiotherapy in reference conditions, Nevertheless it should be increased to include also measurements in non reference conditions. In this paper we present a new dosimetric postal system using thermoluminescent dosimeters (TLD-100 in powder) for photon beams quality control in radiotherapy, in non reference conditions. This system has been checked and appl...

  13. The CNAO dose delivery system for modulated scanning ion beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Giordanengo, S.; Marchetto, F. [Istituto Nazionale di Fisica Nucleare, Section of Torino, Torino 10125 (Italy); Garella, M. A.; Donetti, M. [Istituto Nazionale di Fisica Nucleare, Section of Torino, Torino 10125, Italy and Centro Nazionale Adroterapia Oncologica, Pavia 27100 (Italy); Bourhaleb, F.; Monaco, V.; Hosseini, M. A.; Peroni, C.; Sacchi, R.; Cirio, R. [Istituto Nazionale di Fisica Nucleare, Section of Torino, Torino 10125, Italy and Physics Department, University of Torino, Torino 10125 (Italy); Ciocca, M.; Mirandola, A. [Centro Nazionale Adroterapia Oncologica, Pavia 27100 (Italy)

    2015-01-15

    Purpose: This paper describes the system for the dose delivery currently used at the Centro Nazionale di Adroterapia Oncologica (CNAO) for ion beam modulated scanning radiotherapy. Methods: CNAO Foundation, Istituto Nazionale di Fisica Nucleare and University of Torino have designed, built, and commissioned a dose delivery system (DDS) to monitor and guide ion beams accelerated by a dedicated synchrotron and to distribute the dose with a full 3D scanning technique. Protons and carbon ions are provided for a wide range of energies in order to cover a sizable span of treatment depths. The target volume, segmented in several layers orthogonally to the beam direction, is irradiated by thousands of pencil beams which must be steered and held to the prescribed positions until the prescribed number of particles has been delivered. For the CNAO beam lines, these operations are performed by the DDS. The main components of this system are two independent beam monitoring detectors, called BOX1 and BOX2, interfaced with two control systems performing the tasks of real-time fast and slow control, and connected to the scanning magnets and the beam chopper. As a reaction to any condition leading to a potential hazard, a DDS interlock signal is sent to the patient interlock system which immediately stops the irradiation. The essential tasks and operations performed by the DDS are described following the data flow from the treatment planning system through the end of the treatment delivery. Results: The ability of the DDS to guarantee a safe and accurate treatment was validated during the commissioning phase by means of checks of the charge collection efficiency, gain uniformity of the chambers, and 2D dose distribution homogeneity and stability. A high level of reliability and robustness has been proven by three years of system activity needing rarely more than regular maintenance and working with 100% uptime. Four identical and independent DDS devices have been tested showing

  14. Investigations of high mobility single crystal chemical vapor deposition diamond for radiotherapy photon beam monitoring

    Science.gov (United States)

    Tromson, D.; Descamps, C.; Tranchant, N.; Bergonzo, P.; Nesladek, M.; Isambert, A.

    2008-03-01

    The intrinsic properties of diamond make this material theoretically very suitable for applications in medical physics. Until now ionization chambers have been fabricated from natural stones and are commercialized by PTW, but their fairly high costs and long delivery times have often limited their use in hospital. The properties of commercialized intrinsic polycrystalline diamond were investigated in the past by many groups. The results were not completely satisfactory due to the nature of the polycrystalline material itself. In contrast, the recent progresses in the growth of high mobility single crystal synthetic diamonds prepared by chemical vapor deposition (CVD) technique offer new alternatives. In the framework of the MAESTRO project (Methods and Advanced Treatments and Simulations for Radio Oncology), the CEA-LIST is studying the potentialities of synthetic diamond for new techniques of irradiation such as intensity modulated radiation therapy. In this paper, we present the growth and characteristics of single crystal diamond prepared at CEA-LIST in the framework of the NoRHDia project (Novel Radiation Hard CVD Diamond Detector for Hadrons Physics), as well as the investigations of high mobility single crystal CVD diamond for radiotherapy photon beam monitoring: dosimetric analysis performed with the single crystal diamond detector in terms of stability and repeatability of the response signal, signal to noise ratio, response speed, linearity of the signal versus the absorbed dose, and dose rate. The measurements performed with photon beams using radiotherapy facilities demonstrate that single crystal CVD diamond is a good alternative for air ionization chambers for beam quality control.

  15. Proton microbeam radiotherapy with scanned pencil-beams--Monte Carlo simulations.

    Science.gov (United States)

    Kłodowska, M; Olko, P; Waligórski, M P R

    2015-09-01

    Irradiation, delivered by a synchrotron facility, using a set of highly collimated, narrow and parallel photon beams spaced by 1 mm or less, has been termed Microbeam Radiation Therapy (MRT). The tolerance of healthy tissue after MRT was found to be better than after standard broad X-ray beams, together with a more pronounced response of malignant tissue. The microbeam spacing and transverse peak-to-valley dose ratio (PVDR) are considered to be relevant biological MRT parameters. We investigated the MRT concept for proton microbeams, where we expected different depth-dose profiles and PVDR dependences, resulting in skin sparing and homogeneous dose distributions at larger beam depths, due to differences between interactions of proton and photon beams in tissue. Using the FLUKA Monte Carlo code we simulated PVDR distributions for differently spaced 0.1 mm (sigma) pencil-beams of entrance energies 60, 80, 100 and 120 MeV irradiating a cylindrical water phantom with and without a bone layer, representing human head. We calculated PVDR distributions and evaluated uniformity of target irradiation at distal beam ranges of 60-120 MeV microbeams. We also calculated PVDR distributions for a 60 MeV spread-out Bragg peak microbeam configuration. Application of optimised proton MRT in terms of spot size, pencil-beam distribution, entrance beam energy, multiport irradiation, combined with relevant radiobiological investigations, could pave the way for hypofractionation scenarios where tissue sparing at the entrance, better malignant tissue response and better dose conformity of target volume irradiation could be achieved, compared with present proton beam radiotherapy configurations.

  16. MRI assessment of cervical cancer for adaptive radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Johannes C.A.; Schirl, Gertrude; Baldinger, Anja; Poetter, Richard [Medical Univ. of Vienna (Austria). Dept. of Radiotherapy; Helbich, Thomas H. [Medical Univ. of Vienna (Austria). Dept of Radiology

    2009-05-15

    Purpose: To assess the importance of the information obtained from MRI for adaptive cervix cancer radiotherapy. Patients and methods: 49 patients with cervix cancer, treated by external-beam radiotherapy (EBRT) and MRI-assisted high-dose-rate brachytherapy {+-} concomitant cisplatin, underwent MRI at diagnosis and at the time of brachytherapy fractions. 190 MRI examinations were performed. Pretreatment scans were correlated with clinical examination (CE) findings. Measurements in 3-D of the tumor extension and also of the distance from the tumor to the pelvic side wall were performed using both MRI and CE. The tumor volume regression induced initially by EBRT and the subsequent regression after each brachytherapy fraction were assessed. Results: MRI and CE showed 92% agreement in overall parametrial staging and 73% agreement in terms of vaginal involvement. There was, however, disagreement in parametrial side (right/left) classification in 25% of the parametria examined. These were patients with unilateral displacement of the cervix and contralateral invasion of the parametrium. The mean tumor volume on the pretreatment MRI scan (GTVD) was 61 cm{sup 3}. At the time of the four brachytherapy fractions the mean was 16 cm{sup 3}, 10 cm{sup 3}, 9 cm{sup 3}, and 8 cm{sup 3}, defined as the GTVBT plus the gray zones in the parametria. Conclusion: CE and MRI findings agree well in terms of overall staging. The clinical assessment of side-specific parametrial invasion improved when having access to the additional knowledge obtained from MRI. The greatest decrease in tumor volume occurs during EBRT, whereas tumor regression between the first and subsequent brachytherapy fractions is minor. (orig.)

  17. Incidence of Secondary Cancer Development After High-Dose Intensity-Modulated Radiotherapy and Image-Guided Brachytherapy for the Treatment of Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zelefsky, Michael J., E-mail: Zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Housman, Douglas M.; Pei Xin; Alicikus, Zumre; Magsanoc, Juan Martin [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Dauer, Lawrence T.; St Germain, Jean [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Yamada, Yoshiya; Kollmeier, Marisa; Cox, Brett [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zhang Zhigang [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-07-01

    Purpose: To report the incidence and excess risk of second malignancy (SM) development compared with the general population after external beam radiotherapy (EBRT) and brachytherapy to treat prostate cancer. Methods and Materials: Between 1998 and 2001, 1,310 patients with localized prostate cancer were treated with EBRT (n = 897) or brachytherapy (n = 413). We compared the incidence of SMs in our patients with that of the general population extracted from the National Cancer Institute's Surveillance, Epidemiology, and End Results data set combined with the 2000 census data. Results: The 10-year likelihood of SM development was 25% after EBRT and 15% after brachytherapy (p = .02). The corresponding 10-year likelihood for in-field SM development in these groups was 4.9% and 1.6% (p = .24). Multivariate analysis showed that EBRT vs. brachytherapy and older age were the only significant predictors for the development of all SMs (p = .037 and p = .030), with a trend for older patients to develop a SM. The increased incidence of SM for EBRT patients was explained by the greater incidence of skin cancer outside the radiation field compared with that after brachytherapy (10.6% and 3.3%, respectively, p = .004). For the EBRT group, the 5- and 10-year mortality rate was 1.96% and 5.1% from out-of field cancer, respectively; for in-field SM, the corresponding mortality rates were 0.1% and 0.7%. Among the brachytherapy group, the 5- and 10-year mortality rate related to out-of field SM was 0.8% and 2.7%, respectively. Our observed SM rates after prostate RT were not significantly different from the cancer incidence rates in the general population. Conclusions: Using modern sophisticated treatment techniques, we report low rates of in-field bladder and rectal SM risks after prostate cancer RT. Furthermore, the likelihood of mortality secondary to a SM was unusual. The greater rate of SM observed with EBRT vs. brachytherapy was related to a small, but significantly

  18. Changes in Pulmonary Function After Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, or Proton Beam Therapy for Non-Small-Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Guerra, Jose L. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Hospitales Universitarios Virgen del Rocio, Seville (Spain); Department of Medicine, Universitat Autonoma de Barcelona, Barcelona (Spain); Gomez, Daniel R., E-mail: dgomez@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhuang Yan; Levy, Lawrence B. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Eapen, George [Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liu, Hongmei; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Liao Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-07-15

    Purpose: To investigate the extent of change in pulmonary function over time after definitive radiotherapy for non-small-cell lung cancer (NSCLC) with modern techniques and to identify predictors of changes in pulmonary function according to patient, tumor, and treatment characteristics. Patients and Methods: We analyzed 250 patients who had received {>=}60 Gy radio(chemo)therapy for primary NSCLC in 1998-2010 and had undergone pulmonary function tests before and within 1 year after treatment. Ninety-three patients were treated with three-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy, and 60 with proton beam therapy. Postradiation pulmonary function test values were evaluated among individual patients compared with the same patient's preradiation value at the following time intervals: 0-4 (T1), 5-8 (T2), and 9-12 (T3) months. Results: Lung diffusing capacity for carbon monoxide (DLCO) was reduced in the majority of patients along the three time periods after radiation, whereas the forced expiratory volume in 1 s per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, radiotherapy dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume, lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC. Conclusions: Lung diffusing capacity for carbon monoxide is reduced in the majority of patients after radiotherapy with modern techniques. Multiple factors, including gross tumor volume, preradiation lung function, and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology, such as proton beam therapy or

  19. Endoscopic findings of rectal mucosal damage after pelvic radiotherapy for cervical carcinoma: correlation of rectal mucosal damage with radiation dose and clinical symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Gyu; Huh, Seung Jae; Park, Won [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2013-06-15

    To describe chronic rectal mucosal damage after pelvic radiotherapy (RT) for cervical cancer and correlate these findings with clinical symptoms and radiation dose. Thirty-two patients who underwent pelvic RT were diagnosed with radiation-induced proctitis based on endoscopy findings. The median follow-up period was 35 months after external beam radiotherapy (EBRT) and intracavitary radiotherapy (ICR). The Vienna Rectoscopy Score (VRS) was used to describe the endoscopic findings and compared to the European Organization for Research and Treatment of Cancer (EORTC)/Radiation Therapy Oncology Group (RTOG) morbidity score and the dosimetric parameters of RT (the ratio of rectal dose calculated at the rectal point [RP] to the prescribed dose, biologically effective dose [BED] at the RP in the ICR and EBRT plans, {alpha}/{beta} = 3). Rectal symptoms were noted in 28 patients (rectal bleeding in 21 patients, bowel habit changes in 6, mucosal stools in 1), and 4 patients had no symptoms. Endoscopic findings included telangiectasia in 18 patients, congested mucosa in 20, ulceration in 5, and stricture in 1. The RP ratio, BEDICR, BEDICR+EBRT was significantly associated with the VRS (RP ratio, median 76.5%; BEDICR, median 37.1 Gy3; BEDICR+EBRT, median 102.5 Gy3; p < 0.001). The VRS was significantly associated with the EORTC/RTOG score (p = 0.038). The most prevalent endoscopic findings of RT-induced proctitis were telangiectasia and congested mucosa. The VRS was significantly associated with the EORTC/RTOG score and RP radiation dose.

  20. Telerobotic system concept for real-time soft-tissue imaging during radiotherapy beam delivery

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, Jeffrey; Salisbury, Kenneth; Hristov, Dimitre [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Department of Computer Science and Department of Surgery, Stanford University, Stanford, California 94305 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States)

    2010-12-15

    , as would be enabled by real-time imaging, gross tumor volume coverage was identical while notable reductions of bladder and rectal volumes exposed to large doses were possible. The quality of U.S. images obtained during beam operation was not appreciably degraded by radiofrequency interference and 2D tracking of a phantom object in U.S. images obtained with the beam on/off yielded no significant differences. Conclusions: Remotely controlled robotic U.S. imaging is feasible in the radiotherapy environment and for the first time may offer real-time volumetric soft-tissue guidance concurrent with radiotherapy delivery.

  1. {sup 11}C-Choline PET/CT detects the site of relapse in the majority of prostate cancer patients showing biochemical recurrence after EBRT

    Energy Technology Data Exchange (ETDEWEB)

    Ceci, Francesco; Graziani, Tiziano; Lodi, Filippo; Fanti, Stefano [University of Bologna, Service of Nuclear Medicine, Policlinico S. Orsola Malpighi, Bologna (Italy); Castellucci, Paolo [University of Bologna, Service of Nuclear Medicine, Policlinico S. Orsola Malpighi, Bologna (Italy); Azienda Ospedaliero-Unversitaria di Bologna Policlinico Sant' Orsola-Malpighi, UO di Medicina Nucleare, PAD. 30, Bologna (Italy); Schiavina, Riccardo; Brunocilla, Eugenio; Martorana, Giuseppe [University of Bologna, Department of Urology, Policlinico S. Orsola Malpighi, Bologna (Italy); Mazzarotto, Renzo; Ntreta, Maria [University of Bologna, Service of Radiotherapy, Policlinico S. Orsola Malpighi, Bologna (Italy)

    2014-05-15

    The aim of this retrospective study was to evaluate the usefulness and the detection rate of {sup 11}C-choline PET/CT in a population of patients with prostate cancer (PC), exclusively treated with external beam radiotherapy (EBRT) as primary treatment, who showed biochemical relapse. We enrolled 140 patients showing a serum PSA level >2 ng/mL (mean 8.6 ng/mL, median 5 ng/mL, range 2 - 60 ng/mL). All patients had been treated with EBRT to the prostate gland and prostatic fossa with doses ranging from 70 to 76 Gy in low-risk patients (T1/T2 and/or serum PSA <10 ng/mL) and escalating to >76 Gy (range 76 - 81 Gy) in high-risk patients (T3/T4 and/or serum PSA >10 ng/mL). Of the 140 patients, 53 were receiving androgen deprivation therapy at the time of the scan. All positive {sup 11}C-choline PET/CT findings were validated by transrectal ultrasound-guided biopsy or at least 12 months of follow-up with contrast-enhanced CT, MR, bone scintigraphy or a repeated {sup 11}C-choline PET/CT scan. The relationships between the detection rate of {sup 11}C-choline PET/CT and the factors PSA level, PSA kinetics, Gleason score, age, time to relapse and SUVmax in patients with positive findings were analysed. {sup 11}C-Choline PET/CT detected the site of relapse in 123 of the 140 patients with a detection rate of 87.8 % (46 patients showed local relapse, 31 showed local and distant relapse, and 46 showed only distant relapse). In patients with relapse the mean serum PSA level was 9.08 ng/mL (median 5.1 ng/mL, range 2 - 60 ng/mL), the mean PSA doubling time was 5.6 months (median 3.5 months, range 0.4 - 48 months), and the mean PSA velocity was 15 ng/mL/year (median 8.8 ng/mL/year, range 0.4 - 87 ng/mL/year). Of the 123 patients with relapse, 77 (62.6 %) showed distant relapse with/without local relapse, and of these 77, 31 (40.2 %) showed oligometastatic disease (one or two distant lesions: lymph node lesions only in 16, bone lesions only in 14, and lymph node lesions and bone

  2. Boosting runtime-performance of photon pencil beam algorithms for radiotherapy treatment planning.

    Science.gov (United States)

    Siggel, M; Ziegenhein, P; Nill, S; Oelfke, U

    2012-10-01

    Pencil beam algorithms are still considered as standard photon dose calculation methods in Radiotherapy treatment planning for many clinical applications. Despite their established role in radiotherapy planning their performance and clinical applicability has to be continuously adapted to evolving complex treatment techniques such as adaptive radiation therapy (ART). We herewith report on a new highly efficient version of a well-established pencil beam convolution algorithm which relies purely on measured input data. A method was developed that improves raytracing efficiency by exploiting the capability of modern CPU architecture for a runtime reduction. Since most of the current desktop computers provide more than one calculation unit we used symmetric multiprocessing extensively to parallelize the workload and thus decreasing the algorithmic runtime. To maximize the advantage of code parallelization, we present two implementation strategies - one for the dose calculation in inverse planning software, and one for traditional forward planning. As a result, we could achieve on a 16-core personal computer with AMD processors a superlinear speedup factor of approx. 18 for calculating the dose distribution of typical forward IMRT treatment plans.

  3. Radiotherapy combined with hormonal therapy in prostate cancer: the state of the art.

    Science.gov (United States)

    Milecki, Piotr; Martenka, Piotr; Antczak, Andrzej; Kwias, Zbigniew

    2010-10-11

    Androgen-deprivation therapy (ADT) is used routinely in combination with definitive external beam radiation therapy (EBRT) in patients with high-risk clinically localized or locally advanced disease. The combined treatment (ADT-EBRT) also seems to play a significant role in improving treatment results in the intermediate-risk group of prostate cancer patients. On the other hand, there is a growing body of evidence that treatment with ADT can be associated with serious and lifelong adverse events including osteoporosis, cardiovascular disease, diabetes, and many others. Almost all ADT adverse events are time dependant and tend to increase in severity with prolongation of hormonal manipulation. Therefore, it is crucial to clearly state the optimal schedule for ADT in combination with EBRT, that maintaining the positive effect on treatment efficacy would keep the adverse events risk at reasonable level. To achieve this goal, treatment schedule may have to be highly individualized on the basis of the patient-specific potential vulnerability to adverse events. In this study, the concise and evidence-based review of current literature concerning the general rationales for combining radiotherapy and hormonal therapy, its mechanism, treatment results, and toxicity profile is presented.

  4. Risk of second primary cancer following prostate cancer radiotherapy: DVH analysis using the competitive risk model

    Science.gov (United States)

    Takam, R.; Bezak, E.; Yeoh, E. E.

    2009-02-01

    This study aimed to estimate the risk of developing second primary cancer (SPC) corresponding to various radiation treatment techniques for prostate cancer. Estimation of SPC was done by analysing differential dose-volume histograms (DDVH) of normal tissues such as rectum, bladder and urethra with the competitive risk model. Differential DVHs were obtained from treatment planning systems for external beam radiotherapy (EBRT), low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy techniques. The average risk of developing SPC was no greater than 0.6% for all treatment techniques but was lower with either LDR or HDR brachytherapy alone compared with any EBRT technique. For LDR and HDR brachytherapy alone, the risk of SPC for the rectum was 2.0 × 10-4% and 8.3 × 10-5% respectively compared with 0.2% for EBRT using five-field 3D-CRT to a total dose of 74 Gy. Overall, the risk of developing SPC for urethra following all radiation treatment techniques was very low compared with the rectum and bladder. Treatment plans which deliver equivalent doses of around 3-5 Gy to normal tissues were associated with higher risks of development of SPC.

  5. Risk of second primary cancer following prostate cancer radiotherapy: DVH analysis using the competitive risk model

    Energy Technology Data Exchange (ETDEWEB)

    Takam, R; Bezak, E [School of Chemistry and Physics, University of Adelaide, Adelaide (Australia); Yeoh, E E [School of Medicine, University of Adelaide, Adelaide (Australia)], E-mail: Rungdham.Takam@health.sa.gov.au

    2009-02-07

    This study aimed to estimate the risk of developing second primary cancer (SPC) corresponding to various radiation treatment techniques for prostate cancer. Estimation of SPC was done by analysing differential dose-volume histograms (DDVH) of normal tissues such as rectum, bladder and urethra with the competitive risk model. Differential DVHs were obtained from treatment planning systems for external beam radiotherapy (EBRT), low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy techniques. The average risk of developing SPC was no greater than 0.6% for all treatment techniques but was lower with either LDR or HDR brachytherapy alone compared with any EBRT technique. For LDR and HDR brachytherapy alone, the risk of SPC for the rectum was 2.0 x 10{sup -4}% and 8.3 x 10{sup -5}% respectively compared with 0.2% for EBRT using five-field 3D-CRT to a total dose of 74 Gy. Overall, the risk of developing SPC for urethra following all radiation treatment techniques was very low compared with the rectum and bladder. Treatment plans which deliver equivalent doses of around 3-5 Gy to normal tissues were associated with higher risks of development of SPC.

  6. Intraoperative Radiotherapy for Breast Cancer: The Lasting Effects of a Fleeting Treatment

    Directory of Open Access Journals (Sweden)

    Harriet B. Eldredge-Hindy

    2014-01-01

    Full Text Available In well-selected patients who choose to pursue breast conservation therapy (BCT for early-stage breast cancer, partial breast irradiation (PBI delivered externally or intraoperatively, may be a viable alternative to conventional whole breast irradiation. Two large, contemporary randomized trials have demonstrated breast intraoperative radiotherapy (IORT to be noninferior to whole breast external beam radiotherapy (EBRT when assessing for ipsilateral breast tumor recurrence in select patients. Additionally, IORT and other PBI techniques are likely to be more widely adopted in the future because they improve patient convenience by offering an accelerated course of treatment. Coupled with these novel techniques for breast radiotherapy (RT are distinct toxicity profiles and unique cosmetic alterations that differ from conventional breast EBRT and have the potential to impact disease surveillance and patient satisfaction. This paper will review the level-one evidence for treatment efficacy as well as important secondary endpoints like RT toxicity, breast cosmesis, quality of life, patient satisfaction, and surveillance mammography following BCT with IORT.

  7. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy

    Science.gov (United States)

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  8. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy.

    Science.gov (United States)

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  9. The Results of Intraoperative Radiotherapy for Stomach Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ji Hoon; Kang, Min Kyu; Kim, Myung Se; Kim, Sung Kyu; Yun, Sang Mo; Kim, Sung Hoon [Dept. of Radiation Oncology, Yeungnam University College of Medicine, Daegu (Korea, Republic of)

    2010-11-15

    We retrospectively analyzed the long-term results of radical surgery and intraoperative radiation therapy (IORT) in patients with stomach cancer. From 1988 to 1994, 51 patients were treated with curative surgery and IORT. Postoperative external beam radiotherapy (EBRT) was administered to 30 patients, while adjuvant chemotherapy was administered to 35 patients. A dose of 15 Gy was irradiated with a 9 MeV electron beam as the IORT and a median dose of EBRT was 43.2 Gy (range, 7.2 to 45 Gy). The follow-up period ranged from 1-254 months, with a median follow-up period of 64 months. The median age of all the patients was 58 years (range, 30 to 71 years). The distribution of pathologic stage (American Joint Committee on Cancer [AJCC] 2002 tumor-note-metastasis [TNM]) was as follows: 13 stage I (25.5%), 10 stage II (19.6%), 25 stage III (49.0%), and 3 stage IV (5.9%). Distant metastases occurred in 11 patients (10 in the peritoneum and 1 in bone), including one patient with concurrent local recurrence (anastomosis site). The 5-year locoregional control, disease free survival and overall survival rates were 94.7%, 66.5%, and 51.7%, respectively. For the multivariate analysis, age, TNM stage, and EBRT were significant prognostic factors for overall survival, and only TNM stage for disease free survival. We could have achieved a high loco-regional control rate in patients with locally advanced stomach cancer by adding IORT to radical surgery. However, the benefit of IORT on survival remains to be elucidated.

  10. Cone beam computed tomography guided treatment delivery and planning verification for magnetic resonance imaging only radiotherapy of the brain

    DEFF Research Database (Denmark)

    Edmund, Jens M.; Andreasen, Daniel; Mahmood, Faisal;

    2015-01-01

    Background. Radiotherapy based on MRI only (MRI-only RT) shows a promising potential for the brain. Much research focuses on creating a pseudo computed tomography (pCT) from MRI for treatment planning while little attention is often paid to the treatment delivery. Here, we investigate if cone beam...

  11. Breast Radiotherapy with Mixed Energy Photons; a Model for Optimal Beam Weighting.

    Science.gov (United States)

    Birgani, Mohammadjavad Tahmasebi; Fatahiasl, Jafar; Hosseini, Seyed Mohammad; Bagheri, Ali; Behrooz, Mohammad Ali; Zabiehzadeh, Mansour; Meskani, Reza; Gomari, Maryam Talaei

    2015-01-01

    Utilization of high energy photons (>10 MV) with an optimal weight using a mixed energy technique is a practical way to generate a homogenous dose distribution while maintaining adequate target coverage in intact breast radiotherapy. This study represents a model for estimation of this optimal weight for day to day clinical usage. For this purpose, treatment planning computed tomography scans of thirty-three consecutive early stage breast cancer patients following breast conservation surgery were analyzed. After delineation of the breast clinical target volume (CTV) and placing opposed wedge paired isocenteric tangential portals, dosimeteric calculations were conducted and dose volume histograms (DVHs) were generated, first with pure 6 MV photons and then these calculations were repeated ten times with incorporating 18 MV photons (ten percent increase in weight per step) in each individual patient. For each calculation two indexes including maximum dose in the breast CTV (Dmax) and the volume of CTV which covered with 95% Isodose line (VCTV, 95%IDL) were measured according to the DVH data and then normalized values were plotted in a graph. The optimal weight of 18 MV photons was defined as the intersection point of Dmax and VCTV, 95%IDL graphs. For creating a model to predict this optimal weight multiple linear regression analysis was used based on some of the breast and tangential field parameters. The best fitting model for prediction of 18 MV photons optimal weight in breast radiotherapy using mixed energy technique, incorporated chest wall separation plus central lung distance (Adjusted R2=0.776). In conclusion, this study represents a model for the estimation of optimal beam weighting in breast radiotherapy using mixed photon energy technique for routine day to day clinical usage.

  12. Measurement and properties of dose-area product ratio in external small-beam radiotherapy.

    Science.gov (United States)

    Niemelä, Jarkko Tapio; Partanen, Mari; Ojala, Jarkko; Sipilae, Petri; Björkqvist, Mikko; Kapanen, Mika; Keyriläinen, Jani

    2017-03-22

    In small-beam radiation therapy (RT) the measurement of beam quality parameter i.e. tissue-phantom ratio or TPR20,10 with conventional point detector is a challenge. To obtain reliable results, one has to consider potential sources of error, including volume averaging and adjustment of the point detector into the narrow beam. To overcome these challenges, a different type of possible beam quality parameter in small beams was studied, namely the dose-area product ratio or DAPR20,10. With this method, the measurement of a dose-area product (DAP) with a large-area plane-parallel chamber (LAC) eliminates the uncertainties in detector positioning and volume averaging present with the use of a point detector. In this study, properties of DAPR20,10 of cone-collimated 6 MV photon beam were investigated with Monte Carlo (MC) calculations and the obtained values were compared to measurements obtained by two LAC detectors PTW Type 34073 and PTW Type 34070. In addition, the possibility of determining the DAP with EBT3 film and Razor diode detector was studied. The determination of DAPR20,10 value was found to be feasible in external small-beam radiotherapy of cone-collimated beams with diameters from 4 to 40 mm with the two LACs, MC calculation and Razor diode. Measurements indicated a constant DAPR20,10 value for fields from 20 to 40 mm in diameter with maximum relative change of 0.6%, but an increase of 7.0% for fields from 20 to 4 mm in diameter for PTW Type 34070 chamber. Simulations and measurements showed an increase of DAPR20,10 with increasing LAC size or dose integral area for studied cone-collimated 6 MV photon beams from 4 to 40 mm in diameter. This has a consequence that with reported DAPR20,10 value there should be a reference to the size of the used LAC active area or the DAP integration area.

  13. Prostate image-guided radiotherapy by megavolt cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Zucca, Sergio; Carau, Barbara; Solla, Ignazio; Garibaldi, Elisabetta; Farace, Paolo; Lay, Giancarlo; Meleddu, Gianfranco; Gabriele, Pietro [Regional Oncological Hospital, Cagliari (Italy). Dept. of Radiooncology

    2011-08-15

    To test megavolt cone-beam CT (MV-CBCT) in order to evaluate setup errors in prostate radiotherapy. The setup of 9 patients was verified weekly by electronic portal imaging (EPI) and MV-CBCT, both performed in the same treatment session. EPI were compared with digitally reconstructed radiographies (DRRs). MV-CBCTs were matched to simulation CTs by manual registration based on bone markers (BMR), by manual registration based on soft tissues (STR) - rectum, bladder, and seminal vesicles - and by automatic registration (AR) performed by a mutual information algorithm. Shifts were evaluated along the three main axes: anteroposterior (AP), craniocaudal (CC), and laterolateral (LL). Finally, in 4 additional patients showing intraprostatic calcifications, the calcification mismatch error was used to evaluate the three MV-CBCT matching methods. A total of 50 pairs of orthogonal EPIs and 50 MV-CBCTs were analyzed. Assuming an overall tolerance of 2 mm, no significant differences were observed comparing EPI vs BMR in any axis. A significant difference (p < 0.001) was observed along the AP axis comparing EPI vs AR and EPI vs STR. On the calcification data set (22 measures), the calcification mismatch along the AP direction was significantly lower (p < 0.05) after STR than after BMR or AR. Bone markers were not an effective surrogate of the target position and significant differences were observed comparing EPI or BMR vs STR, supporting the assessment of soft tissue position by MVCBs to verify and correct patient setup in prostate radiotherapy. (orig.)

  14. Evaluation of a plane-parallel ionization chamber for low-energy radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana Paula; Neves, Lucio Pereira; Santos, William de Souza; Caldas, Linda V.E., E-mail: aperini@ipen.br, E-mail: lpneves@ipen.br, E-mail: wssantos@ipen.br, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    A plane-parallel ionization chamber, with a sensitive volume of 6.3 cm{sup 3}, developed at the Calibration Laboratory of IPEN (LCI), was utilized to verify the possibility of its application in low-energy X-ray beam qualities for radiotherapy (T-qualities). This homemade ion chamber was manufactured using polymethyl methacrylate (PMMA) coated with graphite, and co-axial cables. In order to evaluate the performance of this ionization chamber, some characterization tests were performed: short- and medium-term stability, leakage current, saturation, ion collection efficiency, polarity effect and linearity of response. The maximum value obtained in the short-term stability test was 0.2%, in accordance with the limit value of 0.3% provided by the IEC 60731 standard. The saturation curve was obtained varying the applied voltage from -400 V to +400 V, in steps of 50 V, using the charge collecting time of 20 s. From the saturation curve two other characteristics were analyzed: the polarity effect and the ion collection efficiency, with results within the international recommendations. The leakage current of the ionization chamber was measured in time intervals of 20 minutes, before and after its irradiations, and all the results obtained were in agreement with the IEC 60731 standard. The linearity of response was verified utilizing the T-50(b) radiation quality, and the ionization chamber was exposed to different air kerma rates. The response of the ionization chamber presented a linear behavior. Therefore, all results were considered satisfactory, within international recommendations, indicating that this homemade ionization chamber presents potential routine use in dosimetry of low-energy radiotherapy beams. (author)

  15. To analyze the impact of intracavitary brachytherapy as boost radiation after external beam radiotherapy in carcinoma of the external auditory canal and middle ear: A retrospective analysis

    Directory of Open Access Journals (Sweden)

    Dinesh K Badakh

    2014-01-01

    Conclusion: ICBT as a boost after EBRT has got a positive impact on the OS. In conclusion, our results demonstrate that radical radiation therapy (EBRT and ICBT is the treatment of choice for stage T2, carcinoma of EACMA.

  16. Intraoperative Radiotherapy in the Management of Locally Recurrent Extremity Soft Tissue Sarcoma

    Directory of Open Access Journals (Sweden)

    Christopher L. Tinkle

    2015-01-01

    Full Text Available Purpose. To investigate the efficacy and morbidity of limb-sparing surgery with intraoperative radiotherapy (IORT for patients with locally recurrent extremity soft tissue sarcoma (ESTS. Methods and Materials. Twenty-six consecutively treated patients were identified in a single institution retrospective analysis of patients with locally recurrent ESTS treated with IORT following salvage limb-sparing resection from May 2000 to July 2011. Fifteen (58% patients received external beam radiotherapy (EBRT prior to recurrence (median dose 63 Gy, while 11 (42% patients received EBRT following IORT (median dose 52 Gy. The Kaplan-Meier product limit method was used to estimate disease control and survival and subsets were compared using a log rank statistic, Cox’s regression model was used to determine independent predictors of disease outcome, and toxicity was reported according to CTCAE v4.0 guidelines. Results. With a median duration of follow-up from surgery and IORT of 34.9 months (range: 4 to 139 mos., 10 patients developed a local recurrence with 4 subsequently undergoing amputation. The 5-year estimate for local control (LC was 58% (95% CI: 36–75%, for amputation-free was 81% (95% CI: 57–93%, for metastasis-free control (MFC was 56% (95% CI: 31–75%, for disease-free survival (DFS was 35% (95% CI: 17–54%, and for overall survival (OS was 50% (95% CI: 24–71%. Prior EBRT did not appear to influence disease control (LC, p=0.74; MFC, p=0.66 or survival (DFS, p=0.16; OS, p=0.58. Grade 3 or higher acute and late toxicities were reported for 6 (23% and 8 (31% patients, respectively. The frequency of both acute and late grade 3 or higher toxicities occurred equally between patients who received EBRT prior to or after IORT. Conclusions. IORT in combination with oncologic resection of recurrent ESTS yields good rates of local control and limb-salvage with acceptable morbidity. Within the limitations of small subsets, these data suggest

  17. PSMA, EpCAM, VEGF and GRPR as Imaging Targets in Locally Recurrent Prostate Cancer after Radiotherapy

    Directory of Open Access Journals (Sweden)

    Maxim Rybalov

    2014-04-01

    Full Text Available In this retrospective pilot study, the expression of the prostate-specific membrane antigen (PSMA, the epithelial cell adhesion molecule (EpCAM, the vascular endothelial growth factor (VEGF and the gastrin-releasing peptide receptor (GRPR in locally recurrent prostate cancer after brachytherapy or external beam radiotherapy (EBRT was investigated, and their adequacy for targeted imaging was analyzed. Prostate cancer specimens were collected of 17 patients who underwent salvage prostatectomy because of locally recurrent prostate cancer after brachytherapy or EBRT. Immunohistochemistry was performed. A pathologist scored the immunoreactivity in prostate cancer and stroma. Staining for PSMA was seen in 100% (17/17, EpCAM in 82.3% (14/17, VEGF in 82.3% (14/17 and GRPR in 100% (17/17 of prostate cancer specimens. Staining for PSMA, EpCAM and VEGF was seen in 0% (0/17 and for GRPR in 100% (17/17 of the specimens’ stromal compartments. In 11.8% (2/17 of cases, the GRPR staining intensity of prostate cancer was higher than stroma, while in 88.2% (15/17, the staining was equal. Based on the absence of stromal staining, PSMA, EpCAM and VEGF show high tumor distinctiveness. Therefore, PSMA, EpCAM and VEGF can be used as targets for the bioimaging of recurrent prostate cancer after EBRT to exclude metastatic disease and/or to plan local salvage therapy.

  18. Effect of Tissue Composition on Dose Distribution in Electron Beam Radiotherapy

    Directory of Open Access Journals (Sweden)

    Ghorbani M.

    2015-03-01

    Full Text Available Objective: The aim of this study is to evaluate the effect of tissue composition on dose distribution in electron beam radiotherapy. Methods: A Siemens Primus linear accelerator and a phantom were simulated using MCNPX Monte Carlo code. In a homogeneous cylindrical phantom, six types of soft tissue and three types of tissue-equivalent materials were investigated. The tissues included muscle (skeletal, adipose tissue, blood (whole, breast tissue, soft tissue (9-components and soft tissue (4-component. The tissue-equivalent materials were water, A-150 tissue-equivalent plastic and perspex. Electron dose relative to dose in 9-component soft tissue at various depths on the beam’s central axis was determined for 8, 12, and 14 MeV electron energies. Results: The results of relative electron dose in various materials relative to dose in 9-component soft tissue were reported for 8, 12 and 14 MeV electron beams as tabulated data. While differences were observed between dose distributions in various soft tissues and tissue-equivalent materials, which vary with the composition of material, electron energy and depth in phantom, they can be ignored due to the incorporated uncertainties in Monte Carlo calculations. Conclusion: Based on the calculations performed, differences in dose distributions in various soft tissues and tissue-equivalent materials are not significant. However, due to the difference in composition of various materials, further research in this field with lower uncertainties is recommended.

  19. Effect of Tissue Composition on Dose Distribution in Electron Beam Radiotherapy

    Science.gov (United States)

    Ghorbani, M.; Tabatabaei, Z. S.; Vejdani Noghreiyan, A.; Vosoughi, H.; Knaup, C.

    2015-01-01

    Objective The aim of this study is to evaluate the effect of tissue composition on dose distribution in electron beam radiotherapy. Methods A Siemens Primus linear accelerator and a phantom were simulated using MCNPX Monte Carlo code. In a homogeneous cylindrical phantom, six types of soft tissue and three types of tissue-equivalent materials were investigated. The tissues included muscle (skeletal), adipose tissue, blood (whole), breast tissue, soft tissue (9-components) and soft tissue (4-component). The tissue-equivalent materials were water, A-150 tissue-equivalent plastic and perspex. Electron dose relative to dose in 9-component soft tissue at various depths on the beam’s central axis was determined for 8, 12, and 14 MeV electron energies. Results The results of relative electron dose in various materials relative to dose in 9-component soft tissue were reported for 8, 12 and 14 MeV electron beams as tabulated data. While differences were observed between dose distributions in various soft tissues and tissue-equivalent materials, which vary with the composition of material, electron energy and depth in phantom, they can be ignored due to the incorporated uncertainties in Monte Carlo calculations. Conclusion Based on the calculations performed, differences in dose distributions in various soft tissues and tissue-equivalent materials are not significant. However, due to the difference in composition of various materials, further research in this field with lower uncertainties is recommended. PMID:25973407

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-01

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

  1. An international randomised controlled trial to compare TARGeted Intraoperative radioTherapy (TARGIT) with conventional postoperative radiotherapy after breast-conserving surgery for women with early-stage breast cancer (the TARGIT-A trial).

    Science.gov (United States)

    Vaidya, Jayant S; Wenz, Frederik; Bulsara, Max; Tobias, Jeffrey S; Joseph, David J; Saunders, Christobel; Brew-Graves, Chris; Potyka, Ingrid; Morris, Stephen; Vaidya, Hrisheekesh J; Williams, Norman R; Baum, Michael

    2016-01-01

    BACKGROUND Based on our laboratory work and clinical trials we hypothesised that radiotherapy after lumpectomy for breast cancer could be restricted to the tumour bed. In collaboration with the industry we developed a new radiotherapy device and a new surgical operation for delivering single-dose radiation to the tumour bed - the tissues at highest risk of local recurrence. We named it TARGeted Intraoperative radioTherapy (TARGIT). From 1998 we confirmed its feasibility and safety in pilot studies. OBJECTIVE To compare TARGIT within a risk-adapted approach with whole-breast external beam radiotherapy (EBRT) over several weeks. DESIGN The TARGeted Intraoperative radioTherapy Alone (TARGIT-A) trial was a pragmatic, prospective, international, multicentre, non-inferiority, non-blinded, randomised (1 : 1 ratio) clinical trial. Originally, randomisation occurred before initial lumpectomy (prepathology) and, if allocated TARGIT, the patient received it during the lumpectomy. Subsequently, the postpathology stratum was added in which randomisation occurred after initial lumpectomy, allowing potentially easier logistics and a more stringent case selection, but which needed a reoperation to reopen the wound to give TARGIT as a delayed procedure. The risk-adapted approach meant that, in the experimental arm, if pre-specified unsuspected adverse factors were found postoperatively after receiving TARGIT, EBRT was recommended. Pragmatically, this reflected how TARGIT would be practised in the real world. SETTING Thirty-three centres in 11 countries. PARTICIPANTS Women who were aged ≥ 45 years with unifocal invasive ductal carcinoma preferably ≤ 3.5 cm in size. INTERVENTIONS TARGIT within a risk-adapted approach and whole-breast EBRT. MAIN OUTCOME MEASURES The primary outcome measure was absolute difference in local recurrence, with a non-inferiority margin of 2.5%. Secondary outcome measures included toxicity and breast cancer-specific and non

  2. Kilovoltage Rotational External Beam Radiotherapy on a Breast Computed Tomography Platform: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Prionas, Nicolas D.; McKenney, Sarah E. [Department of Radiology, University of California, Davis, Medical Center, Sacramento, California (United States); Stern, Robin L. [Department of Radiation Oncology, University of California, Davis, Medical Center, Sacramento, California (United States); Boone, John M., E-mail: jmboone@ucdavis.edu [Department of Radiology, University of California, Davis, Medical Center, Sacramento, California (United States)

    2012-10-01

    Purpose: To demonstrate the feasibility of a dedicated breast computed tomography (bCT) platform to deliver rotational kilovoltage (kV) external beam radiotherapy (RT) for partial breast irradiation, whole breast irradiation, and dose painting. Methods and Materials: Rotational kV-external beam RT using the geometry of a prototype bCT platform was evaluated using a Monte Carlo simulator. A point source emitting 178 keV photons (approximating a 320-kVp spectrum with 4-mm copper filtration) was rotated around a 14-cm voxelized polyethylene disk (0.1 cm tall) or cylinder (9 cm tall) to simulate primary and primary plus scattered photon interactions, respectively. Simulations were also performed using voxelized bCT patient images. Beam collimation was varied in the x-y plane (1-14 cm) and in the z-direction (0.1-10 cm). Dose painting for multiple foci, line, and ring distributions was demonstrated using multiple rotations with varying beam collimation. Simulations using the scanner's native hardware (120 kVp filtered by 0.2-mm copper) were validated experimentally. Results: As the x-y collimator was narrowed, the two-dimensional dose profiles shifted from a cupped profile with a high edge dose to an increasingly peaked central dose distribution with a sharp dose falloff. Using a 1-cm beam, the cylinder edge dose was <7% of the dose deposition at the cylinder center. Simulations using 120-kVp X-rays showed distributions similar to the experimental measurements. A homogeneous dose distribution (<2.5% dose fluctuation) with a 20% decrease in dose deposition at the cylinder edge (i.e., skin sparing) was demonstrated by weighted summation of four dose profiles using different collimation widths. Simulations using patient bCT images demonstrated the potential for treatment planning and image-guided RT. Conclusions: Rotational kV-external beam RT for partial breast irradiation, dose painting, and whole breast irradiation with skin sparing is feasible on a bCT platform

  3. External-beam radiation therapy after surgical resection and intraoperative electron-beam radiation therapy for oligorecurrent gynecological cancer. Long-term outcome

    Energy Technology Data Exchange (ETDEWEB)

    Sole, C.V. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Complutense University, School of Medicine, Madrid (Spain); Instituto de Radiomedicina, Service of Radiation Oncology, Santiago (Chile); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Calvo, F.A. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Complutense University, School of Medicine, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Lozano, M.A.; Gonzalez-Sansegundo, C. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Service of Radiation Oncology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Gonzalez-Bayon, L. [Hospital General Universitario Gregorio Maranon, Service of General Surgery, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Alvarez, A. [Hospital General Universitario Gregorio Maranon, Service of Radiation Oncology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Lizarraga, S. [Hospital General Universitario Gregorio Maranon, Department of Gynecology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Garcia-Sabrido, J.L. [Complutense University, School of Medicine, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Service of General Surgery, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Department of Gynecology, Madrid (Spain)

    2014-02-15

    The goal of the present study was to analyze prognostic factors in patients treated with external-beam radiation therapy (EBRT), surgical resection and intraoperative electron-beam radiotherapy (IOERT) for oligorecurrent gynecological cancer (ORGC). From January 1995 to December 2012, 61 patients with ORGC [uterine cervix (52 %), endometrial (30 %), ovarian (15 %), vagina (3 %)] underwent IOERT (12.5 Gy, range 10-15 Gy), and surgical resection to the pelvic (57 %) and paraaortic (43 %) recurrence tumor bed. In addition, 29 patients (48 %) also received EBRT (range 30.6-50.4 Gy). Survival outcomes were estimated using the Kaplan-Meier method, and risk factors were identified by univariate and multivariate analyses. Median follow-up time for the entire cohort of patients was 42 months (range 2-169 months). The 10-year rates for overall survival (OS) and locoregional control (LRC) were 17 and 65 %, respectively. On multivariate analysis, no tumor fragmentation (HR 0.22; p = 0.03), time interval from primary tumor diagnosis to locoregional recurrence (LRR) < 24 months (HR 4.02; p = 0.02) and no EBRT at the time of pelvic recurrence (HR 3.95; p = 0.02) retained significance with regard to LRR. Time interval from primary tumor to LRR < 24 months (HR 2.32; p = 0.02) and no EBRT at the time of pelvic recurrence (HR 3.77; p = 0.04) showed a significant association with OS after adjustment for other covariates. External-beam radiation therapy at the time of pelvic recurrence, time interval for relapse ≥24 months and not multi-involved fragmented resection specimens are associated with improved LRC in patients with ORGC. As suggested from the present analysis a significant group of ORGC patients could potentially benefit from multimodality rescue treatment. (orig.)

  4. Knowledge-based prediction of three-dimensional dose distributions for external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Shiraishi, Satomi; Moore, Kevin L., E-mail: kevinmoore@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California 92093 (United States)

    2016-01-15

    Purpose: To demonstrate knowledge-based 3D dose prediction for external beam radiotherapy. Methods: Using previously treated plans as training data, an artificial neural network (ANN) was trained to predict a dose matrix based on patient-specific geometric and planning parameters, such as the closest distance (r) to planning target volume (PTV) and organ-at-risks (OARs). Twenty-three prostate and 43 stereotactic radiosurgery/radiotherapy (SRS/SRT) cases with at least one nearby OAR were studied. All were planned with volumetric-modulated arc therapy to prescription doses of 81 Gy for prostate and 12–30 Gy for SRS. Using these clinically approved plans, ANNs were trained to predict dose matrix and the predictive accuracy was evaluated using the dose difference between the clinical plan and prediction, δD = D{sub clin} − D{sub pred}. The mean (〈δD{sub r}〉), standard deviation (σ{sub δD{sub r}}), and their interquartile range (IQR) for the training plans were evaluated at a 2–3 mm interval from the PTV boundary (r{sub PTV}) to assess prediction bias and precision. Initially, unfiltered models which were trained using all plans in the cohorts were created for each treatment site. The models predict approximately the average quality of OAR sparing. Emphasizing a subset of plans that exhibited superior to the average OAR sparing during training, refined models were created to predict high-quality rectum sparing for prostate and brainstem sparing for SRS. Using the refined model, potentially suboptimal plans were identified where the model predicted further sparing of the OARs was achievable. Replans were performed to test if the OAR sparing could be improved as predicted by the model. Results: The refined models demonstrated highly accurate dose distribution prediction. For prostate cases, the average prediction bias for all voxels irrespective of organ delineation ranged from −1% to 0% with maximum IQR of 3% over r{sub PTV} ∈ [ − 6, 30] mm. The

  5. Secondary external-beam radiotherapy and hyperthermia for local recurrence after 125-iodine implantation in adenocarcinoma of the prostate

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, I.; Kapp, D.S.; Bagshaw, M.A. (Stanford Univ. School of Medicine, CA (USA))

    1991-03-01

    At Standford, six patients underwent a course of external radiotherapy after local recurrence following 125-iodine implantation. Four of the six patients also received concomitant hyperthermia. Four patients were initially managed with hormonal manipulation at time of local relapse and subsequently received external beam radiotherapy with or without hyperthermia. The hyperthermia was non-invasively induced using an annular phased array radiative electromagnetic system. Treatment was well tolerated, and none of the patients experienced severe rectal or bladder complications. Three patients are free from disease; one patient experience local-regional recurrence based on biopsy; one recurred in the bladder, was treated with cystoprostatectomy and subsequently succumbed to metastatic disease; and one patient died of presumed metastatic disease. External-beam irradiation with concurrent hyperthermia can be safely delivered to treat locally recurrent prostatic carcinoma after 125-iodine implantation.

  6. A survey of techniques to reduce and manage external beam radiation-induced xerostomia in British oncology and radiotherapy departments

    Energy Technology Data Exchange (ETDEWEB)

    Macknelly, Andrew [Norfolk and Norwich University Hospital (United Kingdom); Day, Jane [Faculty of Health, Wellbeing and Science, University Campus Suffolk, Waterfront Building, Neptune Quay, Ipswich (United Kingdom)], E-mail: j.day@ucs.ac.uk

    2009-11-15

    Xerostomia is the most common side effect of external beam radiotherapy to the head and neck [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et-al. Can dose reduction to one parotid gland prevent xerostomia? - A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy. Clinical Oncology 2006;18(6):497-504.]. A survey was carried out in British oncology departments to determine what treatment regimes, to minimise xerostomia, are used for patients with head-and-neck cancers treated with external beam radiotherapy. A semi-structured questionnaire consisting of both quantitative and qualitative questions was designed that asked departments which of the identified methods they used, why a method might not be currently employed, and whether its use had ever been considered. The study found that there are wide disparities between the techniques employed by oncology departments to avoid and reduce xerostomia in patients with cancers of the head and neck. The National Institute of Clinical Health and Excellence, [National Institute for Clinical Health and Excellence (NICE). Improving outcomes in head and neck cancers: the manual. London: Office of Public Sector Information; 2004.] for example, recommends that patients are given dental care and dietary advice but some departments did not appear to be doing this. Less than half of departments stated that they offer complementary therapies and less than 40% prescribed pilocarpine, a saliva-stimulant. Only two respondents stated that they use amifostine, a radioprotector, during radiotherapy treatment to the head and neck. The results also suggested a move toward using Intensity Modulated Radiotherapy (IMRT) for treating head-and-neck cancers which offers better normal tissue sparing than three-dimensional conformal radiotherapy. [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et al. Can dose reduction to one parotid gland prevent xerostomia

  7. Theoretical aspects of implementation of kilovoltage cone-beam CT onboard linear accelerator for image-guided radiotherapy.

    Science.gov (United States)

    Rodríguez Cordón, Marta; Ferrer Albiach, Carlos

    2009-08-01

    The main objective of image-guided radiation therapy (IGRT) equipment is to reduce and correct inherent errors in external radiotherapy processes. At the present time, there are different IGRT systems available, but here we will refer exclusively to the kilovoltage cone-beam CT onboard linear accelerator (CBkVCT) and the different aspects that, from a clinical point of view, should be taken into consideration before the implementation of this equipment.

  8. Palladium interstitial implant in combination with external beam radiotherapy and chemotherapy for the definitive treatment of a female urethral carcinoma

    Directory of Open Access Journals (Sweden)

    Hilary P. Bagshaw

    2015-08-01

    Full Text Available Primary urethral cancer is a rare diagnosis, especially in females. This report presents the utilization of a palladium interstitial implant and a review of the retrospective data published on the management of female urethral cancer. Excellent local control and survival has been obtained with the use of a palladium interstitial implant in combination with external beam radiotherapy and concurrent chemotherapy. This modality represents a novel and effective way to treat primary urethral cancer in females.

  9. Matched Cohort Analysis of Outcomes of Definitive Radiotherapy for Prostate Cancer in Human Immunodeficiency Virus-Positive Patients

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, Shannon, E-mail: shannonkahn@yahoo.com [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Jani, Ashesh; Edelman, Scott; Rossi, Peter; Godette, Karen; Landry, Jerome; Anderson, Cynthia [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA (United States)

    2012-05-01

    Purpose: To compare the biochemical outcome and toxicity scores of men with human immunodeficiency virus (HIV) and prostate cancer with a matched control population with negative or unknown HIV status when treated with external-beam radiotherapy (EBRT). Methods and Materials: A single-institution database of men with prostate cancer treated with EBRT from 1999 to 2009 was reviewed. Thirteen men with HIV were identified and matched to 2 control patients according to age, race, T stage, prostate-specific antigen level, Gleason score, RT dose, intensity-modulated RT vs. three-dimensional conformal RT, and whole-pelvis vs. prostate-only RT, for a total of 39 cases. The median follow-up time was 39 months (range, 3-110 months). Results: The 4-year biochemical failure (BF)-free survival rate was 87% in the HIV-positive group vs. 89% in the controls (p = 0.94). Pre- and post-RT viral loads were found to be predictive of BF (p = 0.04 and p = 0.04, respectively). No men with HIV died, whereas 2 in the control group died of causes unrelated to prostate cancer. Acute and chronic genitourinary and gastrointestinal toxicity were less in the HIV-positive patients than in controls (p < 0.001, p < 0.001, p = 0.003, and p < 0.001, respectively). The HIV-positive men experienced an average decline in CD4 count of 193 cells/mm{sup 3}. Conclusions: Our findings suggest that men with HIV treated with EBRT have a similar risk of BF; however, high viral loads may contribute to an increased risk. This analysis supports that HIV-positive men with prostate cancer can be treated with definitive EBRT with similar disease control and toxicity outcomes as in the general population.

  10. Optimization of leaf margins for lung stereotactic body radiotherapy using a flattening filter-free beam

    Energy Technology Data Exchange (ETDEWEB)

    Wakai, Nobuhide, E-mail: wakai@naramed-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan and Department of Radiation Oncology, Nara Medical University, Kashihara, Nara 634-8522 (Japan); Sumida, Iori; Otani, Yuki; Suzuki, Osamu; Seo, Yuji; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Hasegawa, Masatoshi [Department of Radiation Oncology, Nara Medical University, Kashihara, Nara 634-8522 (Japan)

    2015-05-15

    Purpose: The authors sought to determine the optimal collimator leaf margins which minimize normal tissue dose while achieving high conformity and to evaluate differences between the use of a flattening filter-free (FFF) beam and a flattening-filtered (FF) beam. Methods: Sixteen lung cancer patients scheduled for stereotactic body radiotherapy underwent treatment planning for a 7 MV FFF and a 6 MV FF beams to the planning target volume (PTV) with a range of leaf margins (−3 to 3 mm). Forty grays per four fractions were prescribed as a PTV D95. For PTV, the heterogeneity index (HI), conformity index, modified gradient index (GI), defined as the 50% isodose volume divided by target volume, maximum dose (Dmax), and mean dose (Dmean) were calculated. Mean lung dose (MLD), V20 Gy, and V5 Gy for the lung (defined as the volumes of lung receiving at least 20 and 5 Gy), mean heart dose, and Dmax to the spinal cord were measured as doses to organs at risk (OARs). Paired t-tests were used for statistical analysis. Results: HI was inversely related to changes in leaf margin. Conformity index and modified GI initially decreased as leaf margin width increased. After reaching a minimum, the two values then increased as leaf margin increased (“V” shape). The optimal leaf margins for conformity index and modified GI were −1.1 ± 0.3 mm (mean ± 1 SD) and −0.2 ± 0.9 mm, respectively, for 7 MV FFF compared to −1.0 ± 0.4 and −0.3 ± 0.9 mm, respectively, for 6 MV FF. Dmax and Dmean for 7 MV FFF were higher than those for 6 MV FF by 3.6% and 1.7%, respectively. There was a positive correlation between the ratios of HI, Dmax, and Dmean for 7 MV FFF to those for 6 MV FF and PTV size (R = 0.767, 0.809, and 0.643, respectively). The differences in MLD, V20 Gy, and V5 Gy for lung between FFF and FF beams were negligible. The optimal leaf margins for MLD, V20 Gy, and V5 Gy for lung were −0.9 ± 0.6, −1.1 ± 0.8, and −2.1 ± 1.2 mm, respectively, for 7 MV FFF compared

  11. In vivo dosimetry using a single diode for megavoltage photon beam radiotherapy: implementation and response characterization.

    Science.gov (United States)

    Colussi, V C; Beddar, A S; Kinsella, T J; Sibata, C H

    2001-01-01

    The AAPM Task Group 40 reported that in vivo dosimetry can be used to identify major deviations in treatment delivery in radiation therapy. In this paper, we investigate the feasibility of using one single diode to perform in vivo dosimetry in the entire radiotherapeutic energy range regardless of its intrinsic buildup material. The only requirement on diode selection would be to choose a diode with the adequate build up to measure the highest beam energy. We have tested the new diodes from Sun Nuclear Corporation (called QED and ISORAD-p--both p-type) for low-, intermediate-, and high-energy range. We have clinically used both diode types to monitor entrance doses. In general, we found that the dose readings from the ISORAD (p-type) are closer of the dose expected than QED diodes in the clinical setting. In this paper we report on the response of these newly available ISORAD (p-type) diode detectors with respect to certain radiation field parameters such as source-to-surface distance, field size, wedge beam modifiers, as well as other parameters that affect detector characteristics (temperature and detector-beam orientation). We have characterized the response of the high-energy ISORAD (p-type) diode in the low- (1-4 MV), intermediate- (6-12 MV), and high-energy (15-25 MV) range. Our results showed that the total variation of the response of high-energy ISORAD (p-type) diodes to all the above parameters are within +/-5% in most encountered clinical patient treatment setups in the megavoltage photon beam radiotherapy. The usage of the high-energy buildup diode has the additional benefit of amplifying the response of the diode reading in case the wrong energy is used for patient treatment. In the light of these findings, we have since then switched to using only one single diode type, namely the "red" diode; manufacturer designation of the ISORAD (p-type) high-energy (15-25 MV) range diode, for all energies in our institution and satellites.

  12. Investigation of optimal beam margins for stereotactic radiotherapy of lung-cancer using Monte Carlo dose calculations

    Energy Technology Data Exchange (ETDEWEB)

    Jin, L; Wang, L; Li, J; Luo, W; Feigenberg, S J; Ma, C-M [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111 (United States)

    2007-07-21

    This work investigated the selection of beam margins in lung-cancer stereotactic body radiotherapy (SBRT) with 6 MV photon beams. Monte Carlo dose calculations were used to systematically and quantitatively study the dosimetric effects of beam margins for different lung densities (0.1, 0.15, 0.25, 0.35 and 0.5 g cm{sup -3}), planning target volumes (PTVs) (14.4, 22.1 and 55.3 cm{sup 3}) and numbers of beam angles (three, six and seven) in lung-cancer SBRT in order to search for optimal beam margins for various clinical situations. First, a large number of treatment plans were generated in a commercial treatment planning system, and then recalculated using Monte Carlo simulations. All the plans were normalized to ensure that 95% of the PTV at least receives the prescription dose and compared quantitatively. Based on these plans, the relationships between the beam margin and quantities such as the lung toxicity (quantified by V{sub 20}, the percentage volume of the two lungs receiving at least 20 Gy) and the maximum target (PTV) dose were established for different PTVs and lung densities. The impact of the number of beam angles on the relationship between V{sub 20} and the beam margin was assessed. Quantitative information about optimal beam margins for lung-cancer SBRT was obtained for clinical applications.

  13. A study on Fricke-PVA-xylenol orange hydrogel dosimeter for E-beam radiotherapy

    Institute of Scientific and Technical Information of China (English)

    CAO Fangqi; YANG Liming; CHEN Jie; LIN Han; FAN Jinchen; RONG Liang; LUO Wenyun; ZHA Yuanzi; WU Guohua

    2009-01-01

    A Fricke-PVA-xylenol orange (FPX) hydrogel dosimeter, in good transparency, was prepared by physical crosslinking for three-dimensional dose measurements. The process of mixing the chemical dosimeter with the PVA solution was carried out at room temperature, which reduced the influence of auto-oxidation rate. Gradation in color was obviously observed with different distance from the radiation source after 6 MeV electron beam irradiation for radiotherapy. The effects of irradiation dose and three components of the FPX gel dosimeter, i.e. ferrous ions, xylenol orange (XO) and sulphuric acid on sensitivity and stability of dose response were investigated by UV-vis spectropho-tometric measurement. The dose response of the FPX gel dosimeter was linear in the range 0~2.0 Gy. The orthogonal test was employed to find the optimal composition of the gel dosimeter with a sensitivity of about 0.095 cm-1·Gy-1. It was found that XO concentration greatly affected the sensitivity of dose response and lower concentrations of the fer-rous ion and XO gave higher sensitivity within the range 0~2.0 Gy.

  14. Optical eye tracking system for real-time noninvasive tumor localization in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Via, Riccardo, E-mail: riccardo.via@polimi.it; Fassi, Aurora; Fattori, Giovanni [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano 20133 (Italy); Fontana, Giulia; Pella, Andrea; Tagaste, Barbara; Ciocca, Mario [CNAO Centro Nazionale di Adroterapia Oncologica, Pavia 27100 (Italy); Riboldi, Marco; Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano 20133, Italy and CNAO Centro Nazionale di Adroterapia Oncologica, Pavia 27100 (Italy); Orecchia, Roberto [CNAO Centro Nazionale di Adroterapia Oncologica, Pavia 27100, Italy and European Institute of Oncology, Milano 20141 (Italy)

    2015-05-15

    Purpose: External beam radiotherapy currently represents an important therapeutic strategy for the treatment of intraocular tumors. Accurate target localization and efficient compensation of involuntary eye movements are crucial to avoid deviations in dose distribution with respect to the treatment plan. This paper describes an eye tracking system (ETS) based on noninvasive infrared video imaging. The system was designed for capturing the tridimensional (3D) ocular motion and provides an on-line estimation of intraocular lesions position based on a priori knowledge coming from volumetric imaging. Methods: Eye tracking is performed by localizing cornea and pupil centers on stereo images captured by two calibrated video cameras, exploiting eye reflections produced by infrared illumination. Additionally, torsional eye movements are detected by template matching in the iris region of eye images. This information allows estimating the 3D position and orientation of the eye by means of an eye local reference system. By combining ETS measurements with volumetric imaging for treatment planning [computed tomography (CT) and magnetic resonance (MR)], one is able to map the position of the lesion to be treated in local eye coordinates, thus enabling real-time tumor referencing during treatment setup and irradiation. Experimental tests on an eye phantom and seven healthy subjects were performed to assess ETS tracking accuracy. Results: Measurements on phantom showed an overall median accuracy within 0.16 mm and 0.40° for translations and rotations, respectively. Torsional movements were affected by 0.28° median uncertainty. On healthy subjects, the gaze direction error ranged between 0.19° and 0.82° at a median working distance of 29 cm. The median processing time of the eye tracking algorithm was 18.60 ms, thus allowing eye monitoring up to 50 Hz. Conclusions: A noninvasive ETS prototype was designed to perform real-time target localization and eye movement monitoring

  15. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization

    Energy Technology Data Exchange (ETDEWEB)

    Garnica-Garza, H M, E-mail: hgarnica@cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional Unidad Monterrey, Via del Conocimiento 201 Parque de Investigacion e Innovacion Tecnologica, Apodaca NL CP 66600 (Mexico)

    2011-01-21

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 5{sup 0} around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed.

  16. Volumetric Modulation Arc Radiotherapy With Flattening Filter-Free Beams Compared With Static Gantry IMRT and 3D Conformal Radiotherapy for Advanced Esophageal Cancer: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Nicolini, Giorgia, E-mail: giorgia.nicolini@eoc.ch [Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona (Switzerland); Ghosh-Laskar, Sarbani; Shrivastava, Shyam Kishore; Banerjee, Sushovan; Chaudhary, Suresh; Agarwal, Jai Prakash; Munshi, Anusheel [Tata Memorial Hospital, Mumbai (India); Clivio, Alessandro; Fogliata, Antonella [Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona (Switzerland); Mancosu, Pietro [Department of Radiation Oncology, Istituto Clinico Humanitas, Milano-Rozzano (Italy); Vanetti, Eugenio; Cozzi, Luca [Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona (Switzerland)

    2012-10-01

    Purpose: A feasibility study was performed to evaluate RapidArc (RA), and the potential benefit of flattening filter-free beams, on advanced esophageal cancer against intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT). Methods and Materials: The plans for 3D-CRT and IMRT with three to seven and five to seven fixed beams were compared against double-modulated arcs with avoidance sectors to spare the lungs for 10 patients. All plans were optimized for 6-MV photon beams. The RA plans were studied for conventional and flattening filter-free (FFF) beams. The objectives for the planning target volume were the volume receiving {>=}95% or at most 107% of the prescribed dose of <1% with a dose prescription of 59.4 Gy. For the organs at risk, the lung volume (minus the planning target volume) receiving {>=}5 Gy was <60%, that receiving 20 Gy was <20%-30%, and the mean lung dose was <15.0 Gy. The heart volume receiving 45 Gy was <20%, volume receiving 30 Gy was <50%. The spinal dose received by 1% was <45 Gy. The technical delivery parameters for RA were assessed to compare the normal and FFF beam characteristics. Results: RA and IMRT provided equivalent coverage and homogeneity, slightly superior to 3D-CRT. The conformity index was 1.2 {+-} 0.1 for RA and IMRT and 1.5 {+-} 0.2 for 3D-CRT. The mean lung dose was 12.2 {+-} 4.5 for IMRT, 11.3 {+-} 4.6 for RA, and 10.8 {+-} 4.4 for RA with FFF beams, 18.2 {+-} 8.5 for 3D-CRT. The percentage of volume receiving {>=}20 Gy ranged from 23.6% {+-} 9.1% to 21.1% {+-} 9.7% for IMRT and RA (FFF beams) and 39.2% {+-} 17.0% for 3D-CRT. The heart and spine objectives were met by all techniques. The monitor units for IMRT and RA were 457 {+-} 139, 322 {+-} 20, and 387 {+-} 40, respectively. RA with FFF beams showed, compared with RA with normal beams, a {approx}20% increase in monitor units per Gray, a 90% increase in the average dose rate, and 20% reduction in beam on time (owing to different

  17. A novel four-dimensional radiotherapy planning strategy from a tumor-tracking beam's eye view

    Science.gov (United States)

    Li, Guang; Cohen, Patrice; Xie, Huchen; Low, Daniel; Li, Diana; Rimner, Andreas

    2012-11-01

    To investigate the feasibility of four-dimensional radiotherapy (4DRT) planning from a tumor-tracking beam's eye view (ttBEV) with reliable gross tumor volume (GTV) delineation, realistic normal tissue representation, high planning accuracy and low clinical workload, we propose and validate a novel 4D conformal planning strategy based on a synthesized 3.5D computed tomographic (3.5DCT) image with a motion-compensated tumor. To recreate patient anatomy from a ttBEV in the moving tumor coordinate system for 4DRT planning (or 4D planning), the centers of delineated GTVs in all phase CT images of 4DCT were aligned, and then the aligned CTs were averaged to produce a new 3.5DCT image. This GTV-motion-compensated CT contains a motionless target (with motion artifacts minimized) and motion-blurred normal tissues (with a realistic temporal density average). Semi-automatic threshold-based segmentation of the tumor, lung and body was applied, while manual delineation was used for other organs at risk (OARs). To validate this 3.5DCT-based 4D planning strategy, five patients with peripheral lung lesions of small size (<5 cm3) and large motion range (1.2-3.5 cm) were retrospectively studied for stereotactic body radiotherapy (SBRT) using 3D conformal radiotherapy planning tools. The 3.5DCT-based 4D plan (3.5DCT plan) with 9-10 conformal beams was compared with the 4DCT-based 4D plan (4DCT plan). The 4DCT plan was derived from multiple 3D plans based on all phase CT images, each of which used the same conformal beam configuration but with an isocenter shift to aim at the moving tumor and a minor beam aperture and weighting adjustment to maintain plan conformality. The dose-volume histogram (DVH) of the 4DCT plan was created with two methods: one is an integrated DVH (iDVH4D), which is defined as the temporal average of all 3D-phase-plan DVHs, and the other (DVH4D) is based on the dose distribution in a reference phase CT image by dose warping from all phase plans using the

  18. Fifteen-Year Radiotherapy Outcomes of the Randomized PORTEC-1 Trial for Endometrial Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Creutzberg, Carien L., E-mail: c.l.creutzberg@lumc.nl [Department of Clinical Oncology, Leiden University Medical Center (Netherlands); Nout, Remi A. [Department of Clinical Oncology, Leiden University Medical Center (Netherlands); Lybeert, Marnix L.M. [Department of Radiotherapy, Catharina Hospital Eindhoven (Netherlands); Warlam-Rodenhuis, Carla C. [Department of Radiation Oncology, University Medical Center Utrecht (Netherlands); Jobsen, Jan J. [Department of Radiotherapy, Medisch Spectrum Twente, Enschede (Netherlands); Mens, Jan-Willem M. [Department of Radiation Oncology, ErasmusMC-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Lutgens, Ludy C.H.W. [MAASTRO clinic, Maastricht (Netherlands); Pras, Elisabeth [Department of Radiotherapy, University Medical Center Groningen (Netherlands); Poll-Franse, Lonneke V. van de [Comprehensive Cancer Centre South, Eindhoven and Center of Research on Psychology in Somatic Diseases, Tilburg University (Netherlands); Putten, Wim L.J. van [Department of Biostatistics, ErasmusMC-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2011-11-15

    Purpose: To evaluate the very long-term results of the randomized Post Operative Radiation Therapy in Endometrial Carcinoma (PORTEC)-1 trial for patients with Stage I endometrial carcinoma (EC), focusing on the role of prognostic factors for treatment selection and the long-term risk of second cancers. Patients and Methods: The PORTEC trial (1990-1997) included 714 patients with Stage IC Grade 1-2 or Stage IB Grade 2-3 EC. After surgery, patients were randomly allocated to external-beam pelvic radiotherapy (EBRT) or no additional treatment (NAT). Analysis was by intention to treat. Results: 426 patients were alive at the date of analysis. The median follow-up time was 13.3 years. The 15-year actuarial locoregional recurrence (LRR) rates were 6% for EBRT vs. 15.5% for NAT (p < 0.0001). The 15-year overall survival was 52% vs. 60% (p = 0.14), and the failure-free survival was 50% vs. 54% (p = 0.94). For patients with high-intermediate risk criteria, the 15-year overall survival was 41% vs. 48% (p = 0.51), and the 15-year EC-related death was 14% vs. 13%. Most LRR in the NAT group were vaginal recurrences (11.0% of 15.5%). The 15-year rates of distant metastases were 9% vs. 7% (p = 0.25). Second primary cancers had been diagnosed over 15 years in 19% of all patients, 22% vs. 16% for EBRT vs. NAT (p = 0.10), with observed vs. expected ratios of 1.6 (EBRT) and 1.2 (NAT) compared with a matched population (p = NS). Multivariate analysis confirmed the prognostic significance of Grade 3 for LRR (hazard ratio [HR] 3.4, p = 0.0003) and for EC death (HR 7.3, p < 0.0001), of age >60 (HR 3.9, p = 0.002 for LRR and 2.7, p = 0.01 for EC death) and myometrial invasion >50% (HR 1.9, p = 0.03 and HR 1.9, p = 0.02). Conclusions: The 15-year outcomes of PORTEC-1 confirm the relevance of HIR criteria for treatment selection, and a trend for long-term risk of second cancers. EBRT should be avoided in patients with low- and intermediate-risk EC.

  19. Volumetric Modulated Arc Radiotherapy for Early Stage Non-Small-Cell Lung Carcinoma: Is It Better Than the Conventional Static Beam Intensity Modulated Radiotherapy?

    Directory of Open Access Journals (Sweden)

    Vincent Wing Cheung Wu

    2014-01-01

    Full Text Available This study compared the performance of volumetric modulated arc therapy (VMAT techniques: single arc volumetric modulated arc therapy (SA-VMAT and double arc volumetric modulated arc therapy (DA-VMAT with the static beam conventional intensity modulated radiotherapy (C-IMRT for non-small-cell lung carcinoma (NSCLC. Twelve stage I and II NSCLC patients were recruited and their planning CT with contoured planning target volume (PTV and organs at risk (OARs was used for planning. Using the same dose constraints and planning objectives, the C-IMRT, SA-VMAT, and DA-VMAT plans were optimized. C-IMRT consisted of 7 static beams, while SA-VMAT and DA-VMAT plans consisted of one and two full gantry rotations, respectively. No significant difference was found among the three techniques in target homogeneity and conformity. Mean lung dose in C-IMRT plan was significantly lower than that in DA-VMAT plan P=0.04. The ability of OAR sparing was similar among the three techniques, with no significant difference in V20, V10, or V5 of normal lungs, spinal cord, and heart. Less MUs were required in SA-VMAT and DA-VMAT. Besides, SA-VMAT required the shortest beam on time among the three techniques. In treatment of early stage NSCLC, no significant dosimetric superiority was shown by the VMAT techniques over C-IMRT and DA-VMAT over SA-VMAT.

  20. Evaluation of thermoluminescent BeO samples in standard radiotherapy beams; Avaliacao de amostras termoluminescentes de BeO em feixes padroes de radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, Daniela P.; Silva, Jonas O.; Caldas, Linda V.E., E-mail: daniela.piai.groppo@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-08-15

    Beryllium oxide thermoluminescent samples were evaluated in standard radiotherapy beams of low energy. Results for response reproducibility, dose-response curve and energy dependence were obtained. The lower detection limit was determined. The pellets of BeO showed their usefulness for beam dosimetry. (author)

  1. Radiobiologically optimized couch shift: A new localization paradigm using cone-beam CT for prostate radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yimei, E-mail: yhuang2@hfhs.org; Gardner, Stephen J.; Wen, Ning; Zhao, Bo; Gordon, James; Brown, Stephen; Chetty, Indrin J. [Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Boulevard, Detroit, Michigan 48202 (United States)

    2015-10-15

    Purpose: To present a novel positioning strategy which optimizes radiation delivery by utilizing radiobiological response knowledge and evaluate its use during prostate external beam radiotherapy. Methods: Five patients with low or intermediate risk prostate cancer were evaluated retrospectively in this IRB-approved study. For each patient, a VMAT plan with one 358° arc was generated on the planning CT (PCT) to deliver 78 Gy in 39 fractions. Five representative pretreatment cone beam CTs (CBCT) were selected for each patient. The CBCT images were registered to PCT by a human observer, which consisted of an initial automated registration with three degrees-of-freedom, followed by manual adjustment for agreement at the prostate/rectal wall interface. To determine the optimal treatment position for each CBCT, a search was performed centering on the observer-matched position (OM-position) utilizing a score function based on radiobiological and dosimetric indices (EUD{sub prostate}, D99{sub prostate}, NTCP{sub rectum}, and NTCP{sub bladder}) for the prostate, rectum, and bladder. We termed the optimal treatment position the radiobiologically optimized couch shift position (ROCS-position). Results: The dosimetric indices, averaged over the five patients’ treatment plans, were (mean ± SD) 79.5 ± 0.3 Gy (EUD{sub prostate}), 78.2 ± 0.4 Gy (D99{sub prostate}), 11.1% ± 2.7% (NTCP{sub rectum}), and 46.9% ± 7.6% (NTCP{sub bladder}). The corresponding values from CBCT at the OM-positions were 79.5 ± 0.6 Gy (EUD{sub prostate}), 77.8 ± 0.7 Gy (D99{sub prostate}), 12.1% ± 5.6% (NTCP{sub rectum}), and 51.6% ± 15.2% (NTCP{sub bladder}), respectively. In comparison, from CBCT at the ROCS-positions, the dosimetric indices were 79.5 ± 0.6 Gy (EUD{sub prostate}), 77.3 ± 0.6 Gy (D99{sub prostate}), 8.0% ± 3.3% (NTCP{sub rectum}), and 46.9% ± 15.7% (NTCP{sub bladder}). Excessive NTCP{sub rectum} was observed on Patient 5 (19.5% ± 6.6%) corresponding to localization at OM

  2. Dose verification in carcinoma of uterine cervix patients undergoing 3D conformal radiotherapy with Farmer type ion chamber

    Directory of Open Access Journals (Sweden)

    Challapalli Srinivas

    2014-01-01

    Full Text Available External beam radiotherapy (EBRT for carcinoma of uterine cervix is a basic line of treatment with three dimensional conformal radiotherapy (3DCRT in large number of patients. There is need for an established method for verification dosimetry. We tried to document absorbed doses in a group of carcinoma cervix patients by inserting a 0.6 cc Farmer type ion chamber in the vaginal cavity. A special long perspex sleeve cap is designed to cover the chamber for using in the patient′s body. Response of ionization chamber is checked earlier in water phantom with and without cap. Treatment planning was carried out with X-ray computed tomography (CT scan and with the chamber along with cap in inserted position, and with the images Xio treatment planning system. Three measurements on 3 days at 5-6 fraction intervals were recorded in 12 patients. Electrometer measured charges are converted to absorbed dose at the chamber center, in vivo. Our results show good agreement with planned dose within 3% against prescribed dose. This study, is a refinement over our previous studies with transmission dosimetry and chemicals in ampules. This preliminary work shows promise that this can be followed as a routine dose check with special relevance to new protocols in the treatment of carcinoma cervix with EBRT.

  3. Superficial dosimetry imaging of Čerenkov emission in electron beam radiotherapy of phantoms

    Science.gov (United States)

    Zhang, Rongxiao; Fox, Colleen J.; Glaser, Adam K.; Gladstone, David J.; Pogue, Brian W.

    2013-08-01

    Čerenkov emission is generated from ionizing radiation in tissue above 264 keV energy. This study presents the first examination of this optical emission as a surrogate for the absorbed superficial dose. Čerenkov emission was imaged from the surface of flat tissue phantoms irradiated with electrons, using a range of field sizes from 6 cm × 6 cm to 20 cm × 20 cm, incident angles from 0° to 50°, and energies from 6 to 18 MeV. The Čerenkov images were compared with the estimated superficial dose in phantoms from direct diode measurements, as well as calculations by Monte Carlo and the treatment planning system. Intensity images showed outstanding linear agreement (R2 = 0.97) with reference data of the known dose for energies from 6 to 18 MeV. When orthogonal delivery was carried out, the in-plane and cross-plane dose distribution comparisons indicated very little difference (±2-4% differences) between the different methods of estimation as compared to Čerenkov light imaging. For an incident angle 50°, the Čerenkov images and Monte Carlo simulation show excellent agreement with the diode data, but the treatment planning system had a larger error (OPT = ±1˜2%, diode = ±2˜3%, TPS = ±6-8% differences) as would be expected. The sampling depth of superficial dosimetry based on Čerenkov radiation has been simulated in a layered skin model, showing the potential of sampling depth tuning by spectral filtering. Taken together, these measurements and simulations indicate that Čerenkov emission imaging might provide a valuable method of superficial dosimetry imaging from incident radiotherapy beams of electrons.

  4. Development of silicon monolithic arrays for dosimetry in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Bisello, Francesca, E-mail: francesca.bisello@iba-group.com [IBA Dosimetry GmbH, Schwarzenbruck (Germany); Friedrich-Alexander Universität Erlangen—Nürnberg, Erlangen (Germany); Menichelli, David [IBA Dosimetry GmbH, Schwarzenbruck (Germany); Scaringella, Monica [University of Florence, Firenze (Italy); INFN—Florence Division, Sesto Fiorentino (Italy); Talamonti, Cinzia; Zani, Margherita; Bucciolini, Marta [University of Florence, Firenze (Italy); Azienda Ospedaliera Unversitaria Careggi, Firenze (Italy); Bruzzi, Mara [University of Florence, Firenze (Italy); INFN—Florence Division, Sesto Fiorentino (Italy)

    2015-10-01

    New tools for dosimetry in external beam radiotherapy have been developed during last years in the framework of the collaboration among the University of Florence, INFN Florence and IBA Dosimetry. The first step (in 2007) was the introduction in dosimetry of detector solutions adopted from high energy physics, namely epitaxial silicon as the base detector material and a guard ring in diode design. This allowed obtaining state of the art radiation hardness, in terms of sensitivity dependence on accumulated dose, with sensor geometry particularly suitable for the production of monolithic arrays with modular design. Following this study, a 2D monolithic array has been developed, based on 6.3×6.3 cm{sup 2} modules with 3 mm pixel pitch. This prototype has been widely investigated and turned out to be a promising tool to measure dose distributions of small and IMRT fields. A further linear array prototype has been recently design with improve spatial resolution (1 mm pitch) and radiation hardness. This 24 cm long device is constituted by 4×64 mm long modules. It features low sensitivity changes with dose (0.2%/kGy) and dose per pulse (±1% in the range 0.1–2.3 mGy/pulse, covering applications with flattened and unflattened photon fields). The detector has been tested with very satisfactory results as a tool for quality assurance of linear accelerators, with special regards to small fields, and proton pencil beams. In this contribution, the characterization of the linear array with unflattened MV X-rays, {sup 60}Co radiation and 226 MeV protons is reported. - Highlights: • A silicon monolithic 1D array with 1 mm pixel pitch was developed. • The detector was characterized with {sup 60}Co, unflattened MV X-rays, 226 MeV protons. • Dose linearity in clinical relevance range and dose profiles were measured. • The detector performs good agreement with reference detectors. • The technology is suitable in dose profiling in MV X-ray and proton therapy.

  5. TU-EF-304-04: A Heart Motion Model for Proton Scanned Beam Chest Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    White, B; Kiely, J Blanco; Lin, L; Freedman, G; Both, S [University of Pennsylvania, Philadelphia, PA (United States); Vennarini, S [Operativa di Protonterapia, Azienda Provinciale per i Servizi Sanitari, Trento, Trento (Italy); Santhanam, A; Low, D [University of California, Los Angeles, Los Angeles, CA (United States)

    2015-06-15

    Purpose: To model fast-moving heart surface motion as a function of cardiac-phase in order to compensate for the lack of cardiac-gating in evaluating accurate dose to coronary structures. Methods: Ten subjects were prospectively imaged with a breath-hold, cardiac-gated MRI protocol to determine heart surface motion. Radial and planar views of the heart were resampled into a 3-dimensional volume representing one heartbeat. A multi-resolution optical flow deformable image registration algorithm determined tissue displacement during the cardiac-cycle. The surface of the heart was modeled as a thin membrane comprised of voxels perpendicular to a pencil beam scanning (PBS) beam. The membrane’s out-of-plane spatial displacement was modeled as a harmonic function with Lame’s equations. Model accuracy was assessed with the root mean squared error (RMSE). The model was applied to a cohort of six chest wall irradiation patients with PBS plans generated on phase-sorted 4DCT. Respiratory motion was separated from the cardiac motion with a previously published technique. Volumetric dose painting was simulated and dose accumulated to validate plan robustness (target coverage variation accepted within 2%). Maximum and mean heart surface dose assessed the dosimetric impact of heart and coronary artery motion. Results: Average and maximum heart surface displacements were 2.54±0.35mm and 3.6mm from the end-diastole phase to the end-systole cardiac-phase respectively. An average RMSE of 0.11±0.04 showed the model to be accurate. Observed errors were greatest between the circumflex artery and mitral valve level of the heart anatomy. Heart surface displacements correspond to a 3.6±1.0% and 5.1±2.3% dosimetric impact on the maximum and mean heart surface DVH indicators respectively. Conclusion: Although heart surface motion parallel to beam’s direction was substantial, its maximum dosimetric impact was 5.1±2.3%. Since PBS delivers low doses to coronary structures relative to

  6. Role of radiotherapy in the chemotherapy-containing multidisciplinary management of patients with resected pancreatic adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sole, Claudio V. [Instituto de Radiomedicina (IRAM), Department of Radiation Oncology, Santiago (Chile); Complutense University, School of Medicine, Madrid (Spain); Calvo, Felipe A. [Complutense University, School of Medicine, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Atahualpa, Freddy; Gonzalez-Bayon, Luis; Garcia-Sabrido, Jose Luis [Complutense University, School of Medicine, Madrid (Spain); Hospital General Universitario Gregorio Maranon, General Surgery Service III, Madrid (Spain); Berlin, Alejandro [Clinica Alemana de Santiago, Department of Radiation Oncology, Santiago (Chile); Herranz, Rafael [Hospital General Universitario Gregorio Maranon, Department of Radiation Oncology, Madrid (Spain)

    2014-10-08

    To analyze prognostic factors associated with long-term outcomes in patients with resected pancreatic cancer treated with chemotherapy (CT) and surgery with or without external beam radiotherapy (EBRT). From January 1995 to December 2012, 95 patients with adenocarcinoma of the pancreas and locoregional disease [clinical stage IB-IIA (n = 45; 47 %), IIB-IIIC (n = 50; 53 %)] were treated with curative resection [R0 (n = 52; 55 %), R1 (n = 43, 45 %)] and CT with (n = 60; 63 %) or without (n = 35; 37 %) EBRT (45-50.4 Gy). Additionally, 29 patients (48 %) also received a pre-anastomosis IOERT boost (applicator diameter size, 7-10 cm; dose, 10-15 Gy; beam energy, 9-18 MeV). With a median follow-up of 17.2 months (range, 1-182), 2-year overall survival (OS), disease-free survival (DFS), and locoregional control were 28, 20, and 53 %, respectively. Univariate analyses showed that IIB-IIIC stage (HR, 2.23; p = 0.04), R1 margin resection status (HR, 2.09; p = 0.04), no vascular resection (HR, 0.42; p = 0.02), and not receiving external beam radiotherapy (HR, 2.70; p = 0.004) were associated with locoregional recurrence. In the multivariate analysis, only R1 margin resection status (HR, 2.63; p = 0.009) and not receiving EBRT (HR, 2.91; p = 0.002) retained significance with regard to locoregional recurrence. We observed no difference in toxicity between patients treated with or without EBRT (p = 0.44). Overall treatment mortality was 3 %. No long-term treatment-related death occurred. Although adjuvant CT is still the standard of care for resected pancreatic tumors, OS remains modest owing to the high risk of distant metastases. Locoregional treatment needs to be tested in the context of more efficient systemic therapy. (orig.) [German] Zur Evaluierung von Prognosefaktoren im Rahmen von Langzeitresultaten bei Patienten mit reseziertem Pankreaskarzinom und verabreichter Chemotherapie (CT) mit oder ohne zusaetzlicher externer Radiotherapie (EBRT). Von Januar 1995 bis Dezember

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-15

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

  8. Intravitreal bevacizumab for macular edema due to proton beam radiotherapy: Favorable results shown after eighteen months follow-up

    Directory of Open Access Journals (Sweden)

    Eleni Loukianou

    2010-05-01

    Full Text Available Eleni Loukianou, Dimitrios Brouzas, Eleni Georgopoulou, Chrysanthi Koutsandrea, Michael ApostolopoulosEye Department, University of Athens, Athens, GreecePurpose: To evaluate the safety and efficacy of intravitreal injections of bevacizumab (Avastin® as a treatment option for radiation maculopathy secondary to proton beam radiotherapy for choroidal melanoma.Case: A 61-year-old woman presented with a gradual decrease in left eye visual acuity (VA 29 months after proton beam radiotherapy for choroidal melanoma. On presentation, her best-corrected VA (BCVA was 2/10 in the left eye and the intraocular pressure was 15 mmHg. Fundoscopy revealed cystoid macular edema, intraretinal hemorrhages, epiretinal membrane in the posterior pole, and residual tumor scar with exudative retinal detachment and hard exudates in the periphery of the superotemporal quadrant. A treatment with intravitreal injections of bevacizumab (Avastin® was recommended. The injections were performed on a six-weekly basis.Results: The central retinal thickness prior to the treatment was 458 μm. After the first intravitreal injection of bevacizumab, the retinal thickness at the centre of the fovea was reduced to 322 μm. After the third injection, the central retinal thickness was 359 μm and 18 months after presentation, it reduced to 334 μm. The BCVA increased to 3/10 after the intravitreal injections of bevacizumab and remained stable during the follow-up period. The intraocular pressure was within normal range during the follow-up period.Conclusion: Bevacizumab should be regarded as a treatment option for macular edema due to proton beam radiotherapy for choroidal melanoma. By reducing the central retinal thickness, intravitreal bevacizumab can improve VA or ameliorate further decline caused by radiation maculopathy.Keywords: bevacizumab (Avastin®, choroidal melanoma, macular edema, radiation retinopathy

  9. Development and research on the voxelized dose program based on AAPM TG-43 for the brachtherapy combined with EBRT%内外联合照射剂量计算方法的研究

    Institute of Scientific and Technical Information of China (English)

    王彬冰; 狄小云; 李林飞; 毛仙芝; 陈维军; Anupama HA

    2011-01-01

    目的 基于TG-43U1号报告剂量算法开发体元化的铱-192后装剂量计算程序,通过该程序将两个不同治疗计划系统的内外照射计算结果叠加、计算并显示总剂量分布.方法 在开发的后装铱-192剂量计算程序中,根据Nucletron Plato治疗计划系统中读取的后装治疗计划的治疗信息(放射源强度、驻留位置、驻留时间等),重建出参照ADAC治疗计划系统坐标的后装源驻留位置,并重新计算后装治疗计划的三维剂量分布.计算结果经开发的程序转换并输入到ADAC计划系统,在ADAC中重建后装剂量分布并和ADAC外照射计划的剂量分布结果相叠加.结果 根据TG-43U1号报告算法编写的程序剂量计算结果和Nucletron的Plato治疗计划系统得到的计算结果完全一致,误差<0.1%.同时,该计算结果可以在ADAC计划系统上和其他外照射计划进行叠加.结论 笔者编写的铱-192后装剂量计算程序能使不同治疗计划系统的内外照射计算结果叠加,有一定的临床使用价值.%Objective To develop a brachtherapy (BT) dose calculation program based on AAPM TG-43UI formula.With this program we can combine the dose result of external beam radiotherapy (EBRT) and BT together which is calculated by the different treatment planning TPS.Methods BT treatment data, such as source parameter, dwelling position and dwelling time, are retrieved from Nucletron Plato planning system and converted to ADAC planning system coordinate.The BT 3D dose distribution is re-calculated as well.Then the 3D dose distribution is exported to ADAC planning system.In that way, ADAC planning system can display either the EBRT dose or the BT dose and the combined dose can be calculated, displayed and evaluated as well.Results BT dose calculation result of our program which based on AAPM TG-43UI formula is identical with which of Plato (<0.1%).Furthermore, the BT dose can be transfer to the ADAC easily and the dose distributions of

  10. Characterization of a new ionization chamber in radiotherapy beams: angular dependence and variation of response with distance.

    Science.gov (United States)

    Silva, Jonas O; Linda V E, Caldas

    2012-10-01

    A new double faced ionization chamber was constructed at the Calibration Laboratory of IPEN. It has different collecting electrode materials: aluminum and graphite. It was irradiated in standard radiotherapy beams ((60)Co and X-rays). The response variation with distance and the angular dependence of this ionization chamber were evaluated. It was verified that the chamber response follows the inverse square law within a maximum variation of 11.2% in relation to the reference value. For the angular dependence it showed good agreement with international standards.

  11. Dosimetry and microdosimetry using LET spectrometer based on the track-etch detector: radiotherapy Bremsstrahlung beam, onboard aircraft radiation field

    Energy Technology Data Exchange (ETDEWEB)

    Jadrnickova, I. [Dept. of Radiation Dosimetry, Nuclear Physics Institute AS CR, Na Truhlarce 39/64, 180 86 Prague 8 (Czech Republic); Dept. of Dosimetry and Application of Ionizing Radiation, Czech Technical University, Brehova 7, 115 19 Prague 1 (Czech Republic); Spurny, F. [Dept. of Radiation Dosimetry, Nuclear Physics Institute AS CR, Na Truhlarce 39/64, 180 86 Prague 8 (Czech Republic)

    2006-07-01

    The spectrometer of linear energy transfer (Let) based on the chemically etched poly-allyl-diglycol-carbonate (P.A.D.C.) track-etch detector was developed several years ago in our institute. This Let spectrometer enables determining Let of particles approximately from 10 to 700 keV/{mu}m. From the Let spectra, dose characteristics can be calculated. The contribution presents the Let spectra and other dosimetric characteristics obtained onboard a commercial aircraft during more than 6 months long exposure and in the 18 MV radiotherapy Bremsstrahlung beam. (authors)

  12. Quality assurance of U.S.-guided external beam radiotherapy for prostate cancer: report of AAPM Task Group 154.

    Science.gov (United States)

    Molloy, Janelle A; Chan, Gordon; Markovic, Alexander; McNeeley, Shawn; Pfeiffer, Doug; Salter, Bill; Tome, Wolfgang A

    2011-02-01

    Task Group 154 (TG154) of the American Association of Physicists in Medicine (AAPM) was created to produce a guidance document for clinical medical physicists describing recommended quality assurance (QA) procedures for ultrasound (U.S.)-guided external beam radiotherapy localization. This report describes the relevant literature, state of the art, and briefly summarizes U.S. imaging physics. Simulation, treatment planning and treatment delivery considerations are presented in order to improve consistency and accuracy. User training is emphasized in the report and recommendations regarding peer review are included. A set of thorough, yet practical, QA procedures, frequencies, and tolerances are recommended. These encompass recommendations to ensure both spatial accuracy and image quality.

  13. The effectiveness of external beam radiotherapy for acromegaly is not affected by previous pituitary ablative treatments

    Energy Technology Data Exchange (ETDEWEB)

    Reed, P.I.; Joplin, G.F. (Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London (UK)); Speirs, C.J. (Department of Clinical Pharmacology, Royal Postgraduate Medical School, Hammersmith Hospital, London (UK)); Morrison, R. (Department of Radiotherapy, Royal Postgraduate Medical School, Hammersmith Hospital, London (UK)); Aber, V. (Department of Medical Physics, Royal Postgraduate Medical School, Hammersmith Hospital, London (UK))

    1990-01-01

    Thirty-three acromegalic patients were treated with radiotherapy and followed up for at least 3 years (mean 6 years, range 3 to 12). Seventeen had not had previous pituitary ablative therapy and 16 had. The mean GH level for these two groups before radiotherapy was comparable at 98 and 119 mlU/l. The observed frequency of reaching <10 mlU/L was 53% and 75% of patients in the two groups, respectively, the mean observed falls in growth hormone level were 81 and 85% of the initial level, and the calculated exponential decline rate of GH level was 72 and 52% per fyear. Considering all 35 patients, requirement for pituitary hormone replacement therapy increased from 15 patients before radiotherapy to 20 after radiotherapy, being mostly those who had had prior ablative therapies. There were no complications attributable to the radiotherapy treatment. It appears that radiotherapy is equally efficacious whether a prior unsuccessful ablative procedure had been used or not. (author).

  14. Accelerated partial breast irradiation with external beam radiotherapy. First results of the German phase 2 trial

    Energy Technology Data Exchange (ETDEWEB)

    Ott, Oliver J.; Strnad, Vratislav; Stillkrieg, Wilhelm; Fietkau, Rainer [University Hospital Erlangen, Department of Radiation Oncology, Erlangen (Germany); Uter, Wolfgang [University Erlangen-Nuremberg, Dept. of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany); Beckmann, Matthias W. [University Hospital Erlangen, Dept. of Gynecology, Erlangen (Germany)

    2017-01-15

    To evaluate the feasibility and efficacy of external beam three-dimensional (3D) conformal accelerated partial breast irradiation (APBI) for selected patients with early breast cancer. Between 2011 and 2016, 72 patients were recruited for this prospective phase 2 trial. Patients were eligible for APBI if they had histologically confirmed breast cancer or pure ductal carcinoma in situ (DCIS), a tumor diameter ≤3 cm, clear resection margins ≥2 mm, no axillary lymph node involvement, no distant metastases, tumor bed clips, and were aged ≥50 years. Patients were excluded if mammography showed a multicentric invasive growth pattern, or if they had residual diffuse microcalcifications postoperatively, an extensive intraductal component, or vessel invasion. Patients received 3D conformal external beam APBI with a total dose of 38 Gy in 10 fractions in 1-2 weeks. The trial had been registered at the German Clinical Trials Register, DRKS-ID: DRKS00004417. Median follow-up was 25.5 months (range 1-61 months). Local control was maintained in 71 of 72 patients. The 3-year local recurrence rate was 2.1% (95% confidence interval, CI: 0-6.1%). Early toxicity (grade 1 radiodermatitis) was seen in 34.7% (25/72). Late side effects ≥ grade 3 did not occur. Cosmetic results were rated as excellent/good in 96.7% (59/61). APBI with external beam radiotherapy techniques is feasible with low toxicity and, according to the results of the present and other studies, on the way to becoming a standard treatment option for a selected subgroup of patients. (orig.) [German] Untersuchung der Vertraeglichkeit und Sicherheit der externen, 3-D-konformalen akzelerierten Teilbrustbestrahlung (APBI) fuer ausgewaehlte Patientinnen mit einem fruehen Mammakarzinom. Von 2011 bis 2016 wurden 72 Patientinnen in diese prospektive Phase-2-Studie eingebracht. Einschlusskriterien waren ein histologisch gesichertes Mammakarzinom oder DCIS, ein Tumordurchmesser ≤ 3 cm, tumorfreie Resektionsraender ≥ 2

  15. Merkel cell carcinoma: Outcome and role of radiotherapy; Carcinome a cellules de Merkel: prise en charge et place de la radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Salvador Alonso, R.; Lahbabi, I.; Ben Hassel, M.; Boisselier, P.; Crevoisier, R. de [Centre Eugene-Marquis, Dept. de Radiotherapie, 35 - Rennes (France); Chaari, N. [Institut Gustave-Roussy, Dept. de Radiotherapie, 94 - Villejuif (France); Lesimple, T. [Centre Eugene-Marquis, Dept. d' Oncologie Medicale, 35 - Rennes (France); Chevrier, S. [Centre Hospitalier Prive de Saint-Gregoire, Dept. de Chirurgie Plastique, 35 - Saint-Gregoire (France)

    2008-09-15

    Merkel cell carcinoma (M.C.C.) are rare neuroendocrine malignant tumor of the skin, occurring in elderly patients. It affects primarily the sun-exposed areas of the skin, with approximately 50% of all tumors occurring in the face and neck and 40% in the extremities. Immunohistochemical markers (C.K.20+, C.K.7- and T.T.F.1-) are used to distinguish between M.C.C. and other tumors. M.C.C. have a tendency to rapid local progression, frequent spread to regional lymph nodes and distant metastases. Due to the rarity of the disease, the optimal treatment has not been fully defined. Localized stages (stages I and II) are treated by surgical excision of the primary tumor (with 2 to 3 cm margin) and lymphadenectomy in case of node-positive disease, followed by external beam radiotherapy (E.B.R.T.) to a total dose of 50 to 60 Gy in the tumor bed. Adjuvant E.B.R.T. has been shown to decrease markedly locoregional recurrences and to increase survival in recent studies. Treatment of lymph nodes area is more controversial. Chemotherapy is recommended only for metastatic disease. (authors)

  16. Factors influencing the development of ulcers and strictures in carcinoma of the esophagus treated with radiotherapy with or without concurrent chemotherapy

    Directory of Open Access Journals (Sweden)

    Khurana Rohini

    2007-01-01

    Full Text Available Purpose: To ascertain factors that could influence the development of ulcers and strictures in the definitive management of squamous cell carcinoma (SCC of esophagus treated with external beam radiotherapy (EBRT, high-dose-rate (HDR intralumenal radiotherapy (ILRT with or without concurrent weekly cisplatin (CDDP @ 35 mg/m2 chemotherapy (CT. Materials and Methods: Between 1990-2005, 244 patients with inoperable SCC of esophagus were identified from our database and grouped into one of the following: those receiving at least 60Gy EBRT (Gp E, n=44; EBRT followed by HDR-ILRT (Gp E+I, n=98; at least 50Gy EBRT with CT (Gp E+C, n=68; EBRT+HDR-ILRT + CT (Gp E+I+C, n=34. Ulcers (discovered on endoscopy and strictures evident on a barium swallow (which needed dilatations were scored as treatment induced, if the biopsy was negative. Factors likely to influence their outcome were analyzed. Results: The groups were matched for all patient and disease characteristics except pretreatment hemoglobin and Karnofsky performance score (KPS, which were lower in Gp E. The incidence of ulcers was 7%, 8%, 6% and 21% ( P =0.08 while that of strictures was 14%, 9%, 21% and 41% ( P =0.00 for the groups E, E+I, E+C and E+I+C respectively. On univariate analysis, patients with better KPS ( P =0.03, treated with narrow applicators (6 mm vs. 10 mm, P =0.00, received CT ( P =0.00 or assigned to Gp E+I+C ( P =0.00 were more likely to develop strictures, with a trend for development of ulcers in Gp. E+I+C ( P =0.08. Logistic regression retained only Gp E+I+C for development of ulcers (OR 10.36, 95% CI 1.2-89.1, P =0.03 and strictures (OR 4.2, 95% CI 1.4-12.6, P =0.00. Conclusion: Treatment intensification as in Gp E+I+C results in about a three-fold increase in treatment induced late morbidity which can adversely impact on swallowing function and therefore emphasizes the need for optimisation of HDR-ILRT when used in a CT+RT protocol.

  17. Radiotherapy for pituitary adenomas: long-term outcome and complications

    Energy Technology Data Exchange (ETDEWEB)

    Rim, Chai Hong; Yang, Dae Sik; Park, Young Je; Yoon, Won Sup; Lee, Jung AE; Kim, Chul Yong [Korea University Medical Center, Seoul (Korea, Republic of)

    2011-09-15

    To evaluate long-term local control rate and toxicity in patients treated with external beam radiotherapy (EBRT) for pituitary adenomas. We retrospectively reviewed the medical records of 60 patients treated with EBRT for pituitary adenoma at Korea University Medical Center from 1996 and 2006. Thirty-fi ve patients had hormone secreting tumors, 25 patients had non-secreting tumors. Fifty-seven patients had received postoperative radiotherapy (RT), and 3 had received RT alone. Median total dose was 54 Gy (range, 36 to 61.2 Gy). The definition of tumor progression were as follows: evidence of tumor progression on computed tomography or magnetic resonance imaging, worsening of clinical sign requiring additional operation or others, rising serum hormone level against a previously stable or falling value, and failure of controlling serum hormone level so that the hormone level had been far from optimal range until last follow-up. Age, sex, hormone secretion, tumor extension, tumor size, and radiation dose were analyzed for prognostic significance in tumor control. Median follow-up was 5.7 years (range, 2 to 14.4 years). The 10-year actuarial local control rates for non-secreting and secreting adenomas were 96% and 66%, respectively. In univariate analysis, hormone secretion was significant prognostic factor (p = 0.042) and cavernous sinus extension was marginally significant factor (p = 0.054) for adverse local control. All other factors were not significant. In multivariate analysis, hormone secretion and gender were significant. Fifty-three patients had mass-effect symptoms (headache, dizziness, visual disturbance, hypopituitarism, loss of consciousness, and cranial nerve palsy). A total of 17 of 23 patients with headache and 27 of 34 patients with visual impairment were improved. Twenty-seven patients experienced symptoms of endocrine hypersecretion (galactorrhea, amenorrhea, irregular menstruation, decreased libido, gynecomastia, acromegaly, and Cushing

  18. Radiation-induced second primary cancer risks from modern external beam radiotherapy for early prostate cancer: impact of stereotactic ablative radiotherapy (SABR), volumetric modulated arc therapy (VMAT) and flattening filter free (FFF) radiotherapy

    Science.gov (United States)

    Murray, Louise J.; Thompson, Christopher M.; Lilley, John; Cosgrove, Vivian; Franks, Kevin; Sebag-Montefiore, David; Henry, Ann M.

    2015-02-01

    Risks of radiation-induced second primary cancer following prostate radiotherapy using 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), flattening filter free (FFF) and stereotactic ablative radiotherapy (SABR) were evaluated. Prostate plans were created using 10 MV 3D-CRT (78 Gy in 39 fractions) and 6 MV 5-field IMRT (78 Gy in 39 fractions), VMAT (78 Gy in 39 fractions, with standard flattened and energy-matched FFF beams) and SABR (42.7 Gy in 7 fractions with standard flattened and energy-matched FFF beams). Dose-volume histograms from pelvic planning CT scans of three prostate patients, each planned using all 6 techniques, were used to calculate organ equivalent doses (OED) and excess absolute risks (EAR) of second rectal and bladder cancers, and pelvic bone and soft tissue sarcomas, using mechanistic, bell-shaped and plateau models. For organs distant to the treatment field, chamber measurements recorded in an anthropomorphic phantom were used to calculate OEDs and EARs using a linear model. Ratios of OED give relative radiation-induced second cancer risks. SABR resulted in lower second cancer risks at all sites relative to 3D-CRT. FFF resulted in lower second cancer risks in out-of-field tissues relative to equivalent flattened techniques, with increasing impact in organs at greater distances from the field. For example, FFF reduced second cancer risk by up to 20% in the stomach and up to 56% in the brain, relative to the equivalent flattened technique. Relative to 10 MV 3D-CRT, 6 MV IMRT or VMAT with flattening filter increased second cancer risks in several out-of-field organs, by up to 26% and 55%, respectively. For all techniques, EARs were consistently low. The observed large relative differences between techniques, in absolute terms, were very low, highlighting the importance of considering absolute risks alongside the corresponding relative risks, since when absolute

  19. Impact of Immobilization on Intrafraction Motion for Spine Stereotactic Body Radiotherapy Using Cone Beam Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Li, Winnie; Sahgal, Arjun [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Foote, Matthew [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Millar, Barbara-Ann; Jaffray, David A. [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Letourneau, Daniel, E-mail: Daniel.letourneau@rmp.uhn.on.ca [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada)

    2012-10-01

    Purpose: Spine stereotactic body radiotherapy (SBRT) involves tight planning margins and steep dose gradients to the surrounding organs at risk (OAR). This study aimed to assess intrafraction motion using cone beam computed tomography (CBCT) for spine SBRT patients treated using three immobilization devices. Methods and Materials: Setup accuracy using CBCT was retrospectively analyzed for 102 treated spinal metastases in 84 patients. Thoracic and lumbar spine patients were immobilized with either an evacuated cushion (EC, n = 24) or a semirigid vacuum body fixation (BF, n = 60). For cases treated at cervical/upper thoracic (thoracic [T]1-T3) vertebrae, a thermoplastic S-frame (SF) mask (n = 18) was used. Patient setup was corrected by using bony anatomy image registration and couch translations only (no rotation corrections) with shifts confirmed on verification CBCTs. Repeat imaging was performed mid- and post-treatment. Patient translational and rotational positioning data were recorded to calculate means, standard deviations (SD), and corresponding margins {+-} 2 SD for residual setup errors and intrafraction motion. Results: A total of 355 localizations, 333 verifications, and 248 mid- and 280 post-treatment CBCTs were analyzed. Residual translations and rotations after couch corrections (verification scans) were similar for all immobilization systems, with SDs of 0.6 to 0.9 mm in any direction and 0.9 Degree-Sign to 1.6 Degree-Sign , respectively. Margins to encompass residual setup errors after couch corrections were within 2 mm. Including intrafraction motion, as measured on post-treatment CBCTs, SDs for total setup error in the left-right, cranial-caudal, and anterior-posterior directions were 1.3, 1.2, and 1.0 mm for EC; 0.9, 0.7, and 0.9 mm for BF; and 1.3, 0.9, and 1.1 mm for SF, respectively. The calculated margins required to encompass total setup error increased to 3 mm for EC and SF and remained within 2 mm for BF. Conclusion: Following image

  20. External beam radiotherapy for basal cell carcinoma. Local control and cosmetic outcome; Strahlentherapie des Basalzellkarzinoms. Lokale Kontrolle und kosmetisches Ergebnis

    Energy Technology Data Exchange (ETDEWEB)

    Seegenschmiedt, M.H.; Oberste-Beulmann, S.; Guntrum, F.; Olschewski, T. [Krankenhaus Essen (Germany). Klinik fuer Radioonkologie, Strahlentherapie und Nuklearmedizin; Lang, E.; Lang, B. [Praxis fuer Dermatologie, Essen (Germany)

    2001-05-01

    Background: The basal cell carcinoma which is often occurring in the elderly can be well treated by surgery. For large and recurrent lesions and in cosmetically difficult locations external beam radiotherapy provides an equally effective treatment alternative. Patients and Methods: From 1986 to 1999, 60 females and 39 males received primary radiotherapy for a total of 127 histologically verified basal cell carcinoma lesions. Tumors were mostly localized in the face at the temple, nose and forehead. Radiotherapy was applied with orthovoltage equipment and energies of up to 100 kV. Single doses ranged from 2 to 5 Gy related to the 80%-isodose depth. Weekly doses ranged from 8 to 25 Gy and total doses from 25 to 60 Gy. The mean follow-up period was 36{+-}21 months. The acute sequelae were scored according to CTC criteria. Radiogenic late effects as single events were related to the radiation portal. Results: 3 months after treatment all besides one patient (99%) experienced complete tumor remission (CR). In all cases, acute radiation reaction occurred within the radiation portal: CTC Grade 1 in 100%, CTC Grade 2 in 54% and CTC Grade 3 in 30% of the cases. All side effects regressed under simple local measures without further complications. Late sequelae were observed in three cases. Overall cosmetic outcome was good to excellent in almost all patients (98%). In two cases (2%) a local recurrence was observed 6 and 20 months after radiotherapy. Conclusion: External beam (orthovoltage) radiotherapy is very effective and yields high tumor control rates and good cosmetic results in long-term follow-up. Former dermatological treatment concepts should be replaced by an ICRU-based radiophysical dose prescription and should respect the newer radiobiological fractionation principles. (orig.) [German] Hintergrund: Das Basaliom oder Basalzellkarzinom ist ein im Alter haeufig vorkommender Hauttumor, der chirurgisch gut behandelbar ist. Bei grossen und rezidivierenden Tumoren und

  1. SU-D-213-02: Characterization of the Effect of a New Commercial Transmission Detector On Radiotherapy Beams

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, J; Morin, O [University of California San Francisco, San Francisco, CA (United States)

    2015-06-15

    Purpose: To evaluate the influence of a new commercial transmission detector on radiotherapy beams of various energies. Methods: A transmission detector designed for online treatment monitoring was characterized on a TrueBeam STx linear accelerator with 6MV, 6FFF, 10MV, and 10FFF beams. Measurements of beam characteristics including percentage depth doses (PDDs), inplane and crossplane off-axis profiles at different depths, transmission factors, and skin dose were acquired at field sizes of 3×3cm, 5×5m, 10×10cm, and 20×20cm at 100cm and 80cm source-to-surface distance (SSD). All measurements were taken with and without the transmission detector in the path of the beam. A CC04 chamber was used for all profile and transmission factor measurements. Skin dose was assessed at 100cm, 90cm, and 80cm SSD and using a variety of detectors (Roos and Markus parallel-plate chambers, and OSLD). Results: The PDDs showed small differences between the unperturbed and perturbed beams for both 100cm and 80cm SSD (≤4mm dmax difference and <1.2% average profile difference). The differences were larger for the flattened beams and at larger field sizes. The off-axis profiles showed similar trends. The penumbras looked similar with and without the transmission detector. Comparisons in the central 80% of the profile showed a maximum average (maximum) profile difference between all field sizes of 0.756% (1.535%) and 0.739% (3.682%) for 100cm and 80cm SSD, respectively. The average measured skin dose at 100cm (80cm) SSD for 10×10cm field size was <4% (<35%) dose increase for all energies. For 20×20cm field size, this value increased to <10% (≤45%). Conclusion: The transmission detector has minimal effect on the clinically relevant radiotherapy beams for IMRT and VMAT (field sizes 10×10cm and less). For larger field sizes, some perturbations are observable which would need to be assessed for clinical impact. The authors of this publication has research support from IBA Dosimetry.

  2. Treatment planning for radiotherapy with very high-energy electron beams and comparison of VHEE and VMAT plans

    Energy Technology Data Exchange (ETDEWEB)

    Bazalova-Carter, Magdalena; Qu, Bradley; Palma, Bianey; Jensen, Christopher; Maxim, Peter G., E-mail: Peter.Maxim@Stanford.edu, E-mail: BWLoo@Stanford.edu; Loo, Billy W., E-mail: Peter.Maxim@Stanford.edu, E-mail: BWLoo@Stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Hårdemark, Björn; Hynning, Elin [RaySearch Laboratories AB, Stockholm SE-103 65 (Sweden)

    2015-05-15

    Purpose: The aim of this work was to develop a treatment planning workflow for rapid radiotherapy delivered with very high-energy electron (VHEE) scanning pencil beams of 60–120 MeV and to study VHEE plans as a function of VHEE treatment parameters. Additionally, VHEE plans were compared to clinical state-of-the-art volumetric modulated arc therapy (VMAT) photon plans for three cases. Methods: VHEE radiotherapy treatment planning was performed by linking EGSnrc Monte Carlo (MC) dose calculations with inverse treatment planning in a research version of RayStation. In order to study the effect of VHEE treatment parameters on VHEE dose distributions, a MATLAB graphical user interface (GUI) for calculation of VHEE MC pencil beam doses was developed. Through the GUI, pediatric case MC simulations were run for a number of beam energies (60, 80, 100, and 120 MeV), number of beams (13, 17, and 36), pencil beam spot (0.1, 1.0, and 3.0 mm) and grid (2.0, 2.5, and 3.5 mm) sizes, and source-to-axis distance, SAD (40 and 50 cm). VHEE plans for the pediatric case calculated with the different treatment parameters were optimized and compared. Furthermore, 100 MeV VHEE plans for the pediatric case, a lung, and a prostate case were calculated and compared to the clinically delivered VMAT plans. All plans were normalized such that the 100% isodose line covered 95% of the target volume. Results: VHEE beam energy had the largest effect on the quality of dose distributions of the pediatric case. For the same target dose, the mean doses to organs at risk (OARs) decreased by 5%–16% when planned with 100 MeV compared to 60 MeV, but there was no further improvement in the 120 MeV plan. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams, but to a more modest degree (<8%). While pencil beam spacing and SAD had a small effect on VHEE dose distributions, 0.1–3 mm pencil beam sizes resulted in identical dose distributions. For the 100 MeV VHEE pediatric

  3. Radiotherapy Boost for the Dominant Intraprostatic Cancer Lesion-A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    von Eyben, Finn Edler; Kiljunen, Timo; Kangasmaki, Aki; Kairemo, Kalevi; von Eyben, Rie; Joensuu, Timo

    2016-06-01

    External beam radiotherapy (EBRT) for prostate cancer can be performed with a high dose of 86 Gy; however, one-tenth or more of the patients will develop recurrence. Prostate cancer is mainly multifocal, but a dominant intraprostatic lesion (DIL) is often the site of local recurrence after EBRT. We undertook a systematic review and meta-analysis to clarify whether functional imaging might identify the DIL and whether a RT boost to the DIL might be increased to an ultrahigh dose level of ≥ 90 Gy without increased toxicity. Of 62 selected studies, 13 reported the size of the DIL. The mean of the median DIL volumes was 2.4 cm(3) (95% confidence interval, 0.9-4.4 cm(3)). Eighteen diagnostic studies with 1205 patients evaluated the diagnostic accuracy using multiparametric magnetic resonance imaging for intraprostatic cancer lesions. Evaluating 14,654 prostate segments, the diagnostic accuracy was 77%. Eleven therapeutic studies with 988 patients reported a RT boost for the DIL. The summary boost dose for the DIL was a mean of 89 Gy in 5 studies using intensity modulated RT (calculated as the equivalent dose in 2-Gy fractions) and a mean of 141 Gy in 4 studies using a combination of EBRT and brachytherapy (P = .018, t test). In 1 therapeutic study, 239 patients had a 98% 10-year disease-free survival rate. Many of our therapeutic studies used a boost dose to the DIL of > 90 Gy. The reported boost for DIL is effective and safe.

  4. Results of external beam radiotherapy in differentiated thyroid carcinoma: a retrospective study from the Royal Marsden Hospital.

    Science.gov (United States)

    O'Connell, M E; A'Hern, R P; Harmer, C L

    1994-01-01

    Between 1969 and 1991, 113 patients with differentiated thyroid carcinoma (follicular and papillary) received radical dose megavoltage external beam radiotherapy. There were 70 females and 43 males, mean age 53 years (range 11-84). Radiotherapy was delivered to both sides of the neck and superior mediastinum, using either megavoltage photons via anterior and posterior portals, delivering a 60 Gy mid-plane dose in 30 fractions and treating daily over 6 weeks (with spinal cord shielding from the posterior field after 40 Gy), or matched 20 MeV and 35 MeV electron beams (to the neck and superior mediastinum, respectively) delivering a 75 Gy applied dose in 30 daily fractions. All patients received suppressive thyroid hormone and 74 radioiodine. Local recurrence, mostly within field, occurred in 19% of 53 patients with probable and definite residual microscopic disease (both follicular and papillary histologies). For gross residual disease (both follicular and papillary) in 49 patients, complete regression was obtained in 37.5%, partial regression in 25% and no regression in 37.5%. Median follow-up from diagnosis was 49 months (range 3-335). Overall 5-year survival rates were 85% for residual microscopic disease but only 27% for gross disease. 61 patients have died. Nineteen deaths were due to unrelated causes, 15 to distant metastases, 15 to uncontrolled local disease and 12 died with both local and distant tumours.

  5. Persistent pain after targeted intraoperative radiotherapy (TARGIT) or external breast radiotherapy for breast cancer: A randomized trial

    DEFF Research Database (Denmark)

    Andersen, Kenneth Geving; Gärtner, Rune; Kroman, Niels;

    2012-01-01

    Persistent pain after breast cancer treatment (PPBCT) affects between 25 and 60% of patients depending on surgical and adjuvant treatment. External breast radiotherapy (EBRT) has been shown to be a riskfactor for PPBCT, raising the question whether intraoperative radiation therapy (IORT), with its...

  6. Minimal requirements for quality controls in radiotherapy with external beams; Controlli di qualita' essenziali in radioterapia con fasci esterni

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    Physical dosimetric guidelines have been developed by the Italian National Institute of Health study group on quality assurance in radiotherapy to define protocols for quality controls in external beam radiotherapy. While the document does not determine strict rules or firm recommendations, it suggests minimal requirements for quality controls necessary to guarantee an adequate degree of accuracy in external beam radiotherapy. [Italian] Il gruppo di studio Assicurazione di qualita' in radioterapia dell'Istituto Superiore di Sanita' presenta le linee guida per la stesura dei protocolli di controllo di qualita' essenziali necessari a garantire un adeguato livello di accuratezza del trattamento radiante e rappresenta pertanto una parte essenziale del contributo fisico-dosimetrico globale di assicurazione di qualita' in radioterapia con fasci esterni.

  7. Comparative evaluation of a novel 3D segmentation algorithm on in-treatment radiotherapy cone beam CT images

    Science.gov (United States)

    Price, Gareth; Moore, Chris

    2007-03-01

    Image segmentation and delineation is at the heart of modern radiotherapy, where the aim is to deliver as high a radiation dose as possible to a cancerous target whilst sparing the surrounding healthy tissues. This, of course, requires that a radiation oncologist dictates both where the tumour and any nearby critical organs are located. As well as in treatment planning, delineation is of vital importance in image guided radiotherapy (IGRT): organ motion studies demand that features across image databases are accurately segmented, whilst if on-line adaptive IGRT is to become a reality, speedy and correct target identification is a necessity. Recently, much work has been put into the development of automatic and semi-automatic segmentation tools, often using prior knowledge to constrain some grey level, or derivative thereof, interrogation algorithm. It is hoped that such techniques can be applied to organ at risk and tumour segmentation in radiotherapy. In this work, however, we make the assumption that grey levels do not necessarily determine a tumour's extent, especially in CT where the attenuation coefficient can often vary little between cancerous and normal tissue. In this context we present an algorithm that generates a discontinuity free delineation surface driven by user placed, evidence based support points. In regions of sparse user supplied information, prior knowledge, in the form of a statistical shape model, provides guidance. A small case study is used to illustrate the method. Multiple observers (between 3 and 7) used both the presented tool and a commercial manual contouring package to delineate the bladder on a serially imaged (10 cone beam CT volumes ) prostate patient. A previously presented shape analysis technique is used to quantitatively compare the observer variability.

  8. Prognostic Value of External Beam Radiation Therapy in Patients Treated With Surgical Resection and Intraoperative Electron Beam Radiation Therapy for Locally Recurrent Soft Tissue Sarcoma: A Multicentric Long-Term Outcome Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Felipe A. [Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); School of Medicine, Complutense University, Madrid (Spain); Sole, Claudio V., E-mail: cvsole@uc.cl [Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); School of Medicine, Complutense University, Madrid (Spain); Service of Radiation Oncology, Instituto de Radiomedicina, Santiago (Chile); Cambeiro, Mauricio [Service of Radiation Oncology, Clínica Universitaria, Universidad de Navarra, Pamplona (Spain); Montero, Angel; Polo, Alfredo [Service of Radiation Oncology, Hospital Universitario Ramón y Cajal, Universidad de Alcala, Madrid (Spain); Gonzalez, Carmen [School of Medicine, Complutense University, Madrid (Spain); Service of Radiation Oncology, Instituto de Radiomedicina, Santiago (Chile); Service of Radiation Oncology, Clínica Universitaria, Universidad de Navarra, Pamplona (Spain); Service of Radiation Oncology, Hospital Universitario Ramón y Cajal, Universidad de Alcala, Madrid (Spain); Service of Radiation Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); Cuervo, Miguel [Service of Orthopedics and Traumatology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); San Julian, Mikel [Service of Orthopedics and Traumatology, Clínica Universitaria, Universidad de Navarra, Pamplona (Spain); and others

    2014-01-01

    Background: A joint analysis of data from centers involved in the Spanish Cooperative Initiative for Intraoperative Electron Radiotherapy was performed to investigate long-term outcomes of locally recurrent soft tissue sarcoma (LR-STS) patients treated with a multidisciplinary approach. Methods and Materials: Patients with a histologic diagnosis of LR-STS (extremity, 43%; trunk wall, 24%; retroperitoneum, 33%) and no distant metastases who underwent radical surgery and intraoperative electron radiation therapy (IOERT; median dose, 12.5 Gy) were considered eligible for participation in this study. In addition, 62% received external beam radiation therapy (EBRT; median dose, 50 Gy). Results: From 1986 to 2012, a total of 103 patients from 3 Spanish expert IOERT institutions were analyzed. With a median follow-up of 57 months (range, 2-311 months), 5-year local control (LC) was 60%. The 5-year IORT in-field control, disease-free survival (DFS), and overall survival were 73%, 43%, and 52%, respectively. In the multivariate analysis, no EBRT to treat the LR-STS (P=.02) and microscopically involved margin resection status (P=.04) retained significance in relation to LC. With regard to IORT in-field control, only not delivering EBRT to the LR-STS retained significance in the multivariate analysis (P=.03). Conclusion: This joint analysis revealed that surgical margin and EBRT affect LC but that, given the high risk of distant metastases, DFS remains modest. Intensified local treatment needs to be further tested in the context of more efficient concurrent, neoadjuvant, and adjuvant systemic therapy.

  9. Consensus and differences in primary radiotherapy for localized and locally advanced prostate cancer in Switzerland. A survey on patterns of practice

    Energy Technology Data Exchange (ETDEWEB)

    Panje, Cedric M. [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland); Universitaetsspital Zuerich, Department of Radiation Oncology, Zurich (Switzerland); Dal Pra, Alan [Inselspital Bern, Department of Radiation Oncology, Bern (Switzerland); Zilli, Thomas [Hopitaux Universitaires de Geneve, Department of Radiation Oncology, Geneva (Switzerland); Zwahlen, Daniel R. [Kantonsspital Graubuenden, Department of Radiation Oncology, Chur (Switzerland); Papachristofilou, Alexandros [Universitaetsspital Basel, Department of Radiation Oncology, Basel (Switzerland); Herrera, Fernanda G. [Centre Hospitalier Universitaire Vaudois, Department of Radiation Oncology, Lausanne (Switzerland); Matzinger, Oscar [Hopital Riviera-Chablais, Department of Radiation Oncology, Vevey (Switzerland); Plasswilm, Ludwig; Putora, Paul Martin [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland)

    2015-10-15

    External beam radiotherapy (EBRT), with or without androgen deprivation therapy (ADT), is an established treatment option for nonmetastatic prostate cancer. Despite high-level evidence from several randomized trials, risk group stratification and treatment recommendations vary due to contradictory or inconclusive data, particularly with regard to EBRT dose prescription and ADT duration. Our aim was to investigate current patterns of practice in primary EBRT for prostate cancer in Switzerland. Treatment recommendations on EBRT and ADT for localized and locally advanced prostate cancer were collected from 23 Swiss radiation oncology centers. Written recommendations were converted into center-specific decision trees, and analyzed for consensus and differences using a dedicated software tool. Additionally, specific radiotherapy planning and delivery techniques from the participating centers were assessed. The most commonly prescribed radiation dose was 78 Gy (range 70-80 Gy) across all risk groups. ADT was recommended for intermediate-risk patients for 6 months in over 80 % of the centers, and for high-risk patients for 2 or 3 years in over 90 % of centers. For recommendations on combined EBRT and ADT treatment, consensus levels did not exceed 39 % in any clinical scenario. Arc-based intensity-modulated radiotherapy (IMRT) is implemented for routine prostate cancer radiotherapy by 96 % of the centers. Among Swiss radiation oncology centers, considerable ranges of radiotherapy dose and ADT duration are routinely offered for localized and locally advanced prostate cancer. In the vast majority of cases, doses and durations are within the range of those described in current evidence-based guidelines. (orig.) [German] Die Radiotherapie (RT) ist als Monotherapie oder in Kombination mit einer Androgendeprivationstherapie (ADT) eine etablierte Behandlungsoption fuer das lokalisierte und lokal fortgeschrittene Prostatakarzinom. Trotz der guten Evidenzlage durch zahlreiche

  10. Comparison between rad-hard standard float zone (FZ) and magnetic Czochralski (MCZ) silicon diodes in radiotherapy electron beam dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, T.C. dos; Goncalves, J.A.C.; Vasques, M.M.; Tobias, C.C.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes; Neves-Junior, W.F.P.; Haddad, C.M.K. [Hospital Sirio Libanes, Sao Paulo, SP (Brazil). Sociedade Beneficente de Senhoras; Harkonen, J. [Helsinki University of Technology (Denmark). Helsinki Inst. of Physics

    2010-07-01

    Full text. The use of semiconductor detectors has increased in radiotherapy practice since 1980s due to mainly their fast processing time, small sensitive volume and high relative sensitivity to ionizing radiation. Other major advantages of Si devices are excellent repeatability, good mechanical stability, high spatial resolution and the energy independence of mass collision stopping powers ratios (between silicon and water for electron beams with energy from 4 up to 20 MeV). However, ordinary silicon devices are very prone to radiation damage effects. In the last years, the development of radiation tolerant silicon detectors for High Energy Physics experiments has overcome this drawback. In this work we present the preliminary results obtained with a rad-hard epitaxial silicon diode as on-line clinical electron beam dosimeter. The diodes with 25 mm{sup 2} active area, were housed in a PMMA probe and connected, in a photovoltaic mode, to a Keithley 6517B electrometer. During all measurements, the diodes were held between PMMA plates, placed at Zref and centered in a radiation field of 10 cm x 10 cm, with the SSD kept at 100 cm. The devices dosimetric response was evaluated for 6, 9, 12, 15, 18 e 21 MeV electron beams from a Siemens KD 2 Radiotherapy Linear Accelerator, located at Sirio-Libanes Hospital. The radiation induced current in the diodes was registered as a function of the exposure time during 60 s for a fixed 300 MU. To study the short term repeatability, current signals were registered for the same radiation dose, for all energies. The dose-response of the diodes was achieved through the integration of the current signals as a function of the exposure time. The results obtained in the energy range of 6 up to 21 MeV evidenced that, for the same average dose rate of 5.0 cGy/s, the current signals are very stable and repeatable in both cases. For all energies, data shows good instantaneous repeatability with a percentage variation coefficient better than 2

  11. Characterization of standard and oxygenated float zone Si diodes under radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Casati, M. [INFN Firenze and Dipartimento di Fisiopatologia Clinica, University of Florence (Italy)]. E-mail: marta.casati@unifi.it; Bruzzi, M. [INFN Firenze and Dipartimento di Energetica, University of Florence (Italy); Bucciolini, M. [INFN Firenze and Dipartimento di Fisiopatologia Clinica, University of Florence (Italy); Menichelli, D. [INFN Firenze and Dipartimento di Fisiopatologia Clinica, University of Florence (Italy); Scaringella, M. [INFN Firenze and Dipartimento di Energetica, University of Florence (Italy); Piemonte, C. [ITC-IRST, MIS Division, Povo, Trento (Italy); Fretwurst, E. [Institute for Experimental Physics, University of Hamburg D-22761 (Germany)

    2005-10-21

    The dosimetric response of silicon diodes made from high resistivity float zone (FZ) and diffusion oxygenated FZ (DOFZ) silicon has been studied with a {sup 60}Co clinical radiotherapy gamma source. To investigate the changes in sensitivity with the accumulated dose, the diodes have been exposed to doses of {sup 137}Cs gamma-rays up to 6 kGy. As expected, Si diodes showed a degradation in the signal response with the accumulated dose due to the formation of radiation-induced defects acting as lifetime killers. Nonetheless, the DOFZ Si diode appeared to be moderately radiation harder than the standard FZ sample, with a decay of sensitivity less pronounced.

  12. Advanced Electron Beam Ion Sources (EBIS) for 2-nd generation carbon radiotherapy facilities

    CERN Document Server

    Shornikov, A.

    2016-01-01

    In this work we analyze how advanced Electron Beam Ion Sources (EBIS) can facilitate the progress of carbon therapy facilities. We will demonstrate that advanced ion sources enable operation of 2-nd generation ion beam therapy (IBT) accelerators. These new accelerator concepts with designs dedicated to IBT provide beams better suited for therapy and, are more cost efficient than contemporary IBT facilities. We will give a sort overview of the existing new IBT concepts and focus on those where ion source technology is the limiting factor. We will analyse whether this limitation can be overcome in the near future thanks to ongoing EBIS development.

  13. A One-Step Cone-Beam CT-Enabled Planning-to-Treatment Model for Palliative Radiotherapy-From Development to Implementation

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Rebecca K.S., E-mail: rebecca.wong@rmp.uhn.on.ca [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Letourneau, Daniel; Varma, Anita [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Bissonnette, Jean Pierre; Fitzpatrick, David; Grabarz, Daniel; Elder, Christine [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Martin, Melanie; Bezjak, Andrea [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Panzarella, Tony [Department of Biostatistics, Princess Margaret Hospital, Toronto, Ontario (Canada); Gospodarowicz, Mary [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada)

    2012-11-01

    Purpose: To develop a cone-beam computed tomography (CT)-enabled one-step simulation-to-treatment process for the treatment of bone metastases. Methods and Materials: A three-phase prospective study was conducted. Patients requiring palliative radiotherapy to the spine, mediastinum, or abdomen/pelvis suitable for treatment with simple beam geometry ({<=}2 beams) were accrued. Phase A established the accuracy of cone-beam CT images for the purpose of gross tumor target volume (GTV) definition. Phase B evaluated the feasibility of implementing the cone-beam CT-enabled planning process at the treatment unit. Phase C evaluated the online cone-beam CT-enabled process for the planning and treatment of patients requiring radiotherapy for bone metastases. Results: Eighty-four patients participated in this study. Phase A (n = 9) established the adequacy of cone-beam CT images for target definition. Phase B (n = 45) established the quality of treatment plans to be adequate for clinical implementation for bone metastases. When the process was applied clinically in bone metastases (Phase C), the degree of overlap between planning computed tomography (PCT) and cone-beam CT for GTV and between PCT and cone-beam CT for treatment field was 82% {+-} 11% and 97% {+-} 4%, respectively. The oncologist's decision to accept the plan under a time-pressured environment remained of high quality, with the cone-beam CT-generated treatment plan delivering at least 90% of the prescribed dose to 100% {+-} 0% of the cone-beam CT planning target volume (PTV). With the assumption that the PCT PTV is the gold-standard target, the cone-beam CT-generated treatment plan delivered at least 90% and at least 95% of dose to 98% {+-} 2% and 97% {+-} 5% of the PCT PTV, respectively. The mean time for the online planning and treatment process was 32.7 {+-} 4.0 minutes. Patient satisfaction was high, with a trend for superior satisfaction with the cone-beam CT-enabled process. Conclusions: The cone-beam

  14. A GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    CERN Document Server

    Gu, Xuejun; Li, Jinsheng; Jia, Xun; Jiang, Steve B

    2011-01-01

    Targeting at developing an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite size pencil beam (FSPB) algorithm with a 3D-density correction method on GPU. This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework [Gu et al. Phys. Med. Biol. 54 6287-97, 2009]. Dosimetric evaluations against MCSIM Monte Carlo dose calculations are conducted on 10 IMRT treatment plans with heterogeneous treatment regions (5 head-and-neck cases and 5 lung cases). For head and neck cases, when cavities exist near the target, the improvement with the 3D-density correction over the conventional FSPB algorithm is significant. However, when there are high-density dental filling materials in beam paths, the improvement is small and the accuracy of the new algorithm is still unsatisfactory. On the other hand, significant improvement of dose calculation accuracy is observed in all lung cases. Especially when the target is in the m...

  15. SU-E-T-415: An Ionization Chamber Array with High Spatial Resolution for External Beam Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Togno, M [Klinikum rechts der Isar, Technische Universitaet Muenchen, Muenchen (Germany); IBA Dosimetry, Schwarzenbruck (Germany); Wilkens, J [Klinikum rechts der Isar, Technische Universitaet Muenchen, Muenchen (Germany); Menichelli, D [IBA Dosimetry, Schwarzenbruck (Germany)

    2014-06-01

    Purpose: To characterize an ionization chamber array technology with high spatial resolution and high charge collection efficiency for external beam radiotherapy. Methods: The prototype under test is a linear array of air vented ionization chambers developed by IBA Dosimetry, consisting of 80 pixels with 3.5mm spatial resolution and 4mm{sup 3} sensitive volume. The detector was characterized in a plastic phantom with {sup 60} Co radiation and MV X-rays from an ELEKTA Agility LINAC (with flattened and unflattened beam qualities). Bias voltage was varied in order to evaluate charge collection efficiency. A commercial array of ionization chambers (MatriXX Evolution, IBA Dosimetry) and an amorphous silicon flat panel in direct conversion configuration were used as references. Results: Repeatability (0.4%) and stability under continuous gamma irradiation (0.3%) are very good, in spite of low active volume and sensitivity (∼200pC/Gy). Charge collection efficiency is higher than 99% already at 150V with ∼2mGy dose per pulse, leading to a ±1.1% sensitivity change with dose per pulse in the range 0.09-2mGy (covering all flattened and unflattened applications). Measured dose profiles are in agreement with MatriXX for fields larger than 2×2cm{sup 2}, in which case the linear array offers a much better characterization of the penumbra region. Down to 1×1cm{sup 2}, measured profiles are in very good agreement with the flat panel. Conclusion: The array represents a valuable tool for the characterization of treatment fields in which high spatial resolution is required, together with the dosimetric performance of air vented ionization chambers. Such a technology would be particularly valuable in association with advanced treatment modalities such as rotational radiotherapy, stereotactic treatments (even with unflattened beam qualities) and proton therapy, due to the insensitivity of the chambers on dose per pulse. In the future, a two dimensional prototype based on this

  16. Dosimetric characterization of the iBEAM evo carbon fiber couch for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David W.; Christophides, Damianos; Dean, Christopher; Naisbit, Mitchell; Mason, Joshua; Morgan, Andrew [Department of Medical Physics and Clinical Engineering, St. James' s Institute of Oncology, Bexley Wing, St. James' s University Hospital, Leeds LS9 7TF (United Kingdom); Department of Medical Physics, St. Bartholomew' s Hospital, Barts and London NHS Trust, West Smithfield, London EC1A 7BE (United Kingdom); Department of Medical Physics and Clinical Engineering, St. James' s Institute of Oncology, Bexley Wing, St. James' s University Hospital, Leeds LS9 7TF (United Kingdom); Radiotherapy Physics Department, Beacon Centre, Musgrove Park Hospital, Taunton, Somerset TA1 5DA (United Kingdom)

    2010-07-15

    Purpose: This study characterizes the dosimetric properties of the iBEAM evo carbon fiber couch manufactured by Medical Intelligence and examines the accuracy of the CMS XiO and Nucletron Oncentra Masterplan (OMP) treatment planning systems for calculating beam attenuation due to the presence of the couch. Methods: To assess the homogeneity of the couch, it was CT scanned at isocentric height and a number of signal intensity profiles were generated and analyzed. To simplify experimental procedures, surface dose and central axis depth dose measurements were performed in a solid water slab phantom using Gafchromic film for 6 and 10 MV photon beams at gantry angles of 0 deg. (normal incidence), 30 deg., and 60 deg. with an inverted iBEAM couch placed on top of the phantom. Attenuation measurements were performed in a cylindrical solid water phantom with an ionization chamber positioned at the isocenter. Measurements were taken for gantry angles from 0 deg. to 90 deg. in 10 deg. increments for both 6 and 10 MV photon beams. This setup was replicated in the XiO and OMP treatment planning systems. Dose was calculated using the pencil beam, collapsed cone, convolution, and superposition algorithms. Results: The CT scan of the couch showed that it was uniformly constructed. Surface dose increased by (510{+-}30)% for a 6 MV beam and (600{+-}20)% for a 10 MV beam passing through the couch at normal incidence. Obliquely incident beams resulted in a higher surface dose compared to normally incident beams for both open fields and fields with the couch present. Depth dose curves showed that the presence of the couch resulted in an increase in dose in the build up region. For 6 and 10 MV beams incident at 60 deg., nearly all skin sparing was lost. Attenuation measurements derived using the ionization chamber varied from 2.7% (0 deg.) to a maximum of 4.6% (50 deg.) for a 6 MV beam and from 1.9% (0 deg.) to a maximum of 4.0% (50 deg.) for a 10 MV beam. The pencil beam and

  17. Prediction of lung density changes after radiotherapy by cone beam computed tomography response markers and pre-treatment factors for non-small cell lung cancer patients

    DEFF Research Database (Denmark)

    Bernchou, Uffe; Hansen, Olfred; Schytte, Tine;

    2015-01-01

    BACKGROUND AND PURPOSE: This study investigates the ability of pre-treatment factors and response markers extracted from standard cone-beam computed tomography (CBCT) images to predict the lung density changes induced by radiotherapy for non-small cell lung cancer (NSCLC) patients. METHODS...... AND MATERIALS: Density changes in follow-up computed tomography scans were evaluated for 135 NSCLC patients treated with radiotherapy. Early response markers were obtained by analysing changes in lung density in CBCT images acquired during the treatment course. The ability of pre-treatment factors and CBCT...... markers to predict lung density changes induced by radiotherapy was investigated. RESULTS: Age and CBCT markers extracted at 10th, 20th, and 30th treatment fraction significantly predicted lung density changes in a multivariable analysis, and a set of response models based on these parameters were...

  18. External Beam Radiotherapy for Focal Lymphoepithelioma-Like Carcinoma in the Urinary Bladder: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Nobuhiro Kushida

    2015-01-01

    Full Text Available Lymphoepithelioma is a malignant epithelial tumor in the nasopharynx characterized by prominent lymphoid infiltration. Carcinomas that resemble lymphoepitheliomas have been called lymphoepithelioma-like carcinomas and have been reported in other organs. A tumor in the bladder is categorized by the percentage of the total area occupied by the lymphoepithelioma-like carcinoma pattern, with the prognosis dependent on the percentage. We present an 81-year-old man with stage 3 chronic obstructive pulmonary disease and a history of aortic aneurysm repair. The computed tomography scans indicated thickening and irregularity of the bladder wall, with left external iliac lymph node metastasis. His diagnosis was bladder cancer, and the clinical stage was evaluated as T3N1M0. Transurethral resection of the bladder tumor was performed, and the pathological specimen showed that the tumor was composed of undifferentiated malignant cells with sheets and nests arranged in a syncytial pattern, as well as an urothelial carcinoma lesion. A prominent lymphoid reaction accompanied the tumor. The pathological diagnosis was focal-type lymphoepithelioma-like carcinoma containing a component of urothelial carcinoma G3>G2. His general condition was such that he could not tolerate radical cystectomy or systemic chemotherapy. External beam radiotherapy (total 60 Gy was given to the bladder, including the lymph node metastatic lesion. No cancer recurrence was detected by regular follow-up computed tomography and cystoscopy. He eventually died of other causes 48 months later. Although treatment for focal lymphoepithelioma-like carcinoma generally requires multifocal therapies, in the present case, the bladder became tumor free. We also summarize previously reported lymphoepithelioma-like carcinoma cases treated with radiotherapy.

  19. Salvage external beam radiotherapy for prostate cancer after radical prostatectomy: current status and controversy.

    Science.gov (United States)

    Raldow, Ann; Hamstra, Daniel A; Kim, Sung; Yu, James B

    2010-07-01

    Prostate cancer is the second most common cause of cancer death in American men. What to do when prostate cancer recurs months or years after a patient undergoes radical prostatectomy is an area of active research. Patients who underwent radical prostatectomy without immediate adjuvant radiation therapy (ART) but subsequently have evidence of recurrent disease are candidates for Salvage Radiation Therapy (SRT). Though there are three prospective randomized trials illustrating the efficacy of post-operative ART for selected patients, similarly strong evidence is lacking for SRT. In this article, we define the biochemical recurrence of prostate cancer, distinguish SRT from ART, outline the evidence for SRT, and make recommendations with regard to radiotherapy volume and dose. We discuss the known side effects from SRT, weigh the cost and benefit of SRT, and discuss possible tools that may improve the cost/benefit ratio for SRT by helping to select patients whom SRT may be more likely to benefit.

  20. SU-E-T-770: Tumor Control in Ion Beam Radiotherapy with Different Ions in Presence of Hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Attili, A; Giordanengo, S [Istituto Nazionale di Fisica Nucleare, Sez. Torino, Torino (Italy); Torriani, F [Politecnico di Torino, Torino (Italy); Russo, G; Ourhaleb, F [Internet-Simulation Evaluation, Envision, Torino (Italy); Dalmasso, F; Cirio, R [Istituto Nazionale di Fisica Nucleare, Sez. Torino, Torino (Italy); Universita degli Studi di Torino, Torino (Italy); Battistoni, G [Istituto Nazionale di Fisica Nucleare, Sez. Milano, Milano (Italy); Kraan, A [Istituto Nazionale di Fisica Nucleare, Sez. Pisa, Pisa (Italy); Universita degli Studi di Pisa, Pisa (Italy)

    2015-06-15

    Purpose: The reduced concentration of oxygen in cells (hypoxia) results in a lower cell death rate after irradiation that can lead to treatment failure. The effect can be expressed by the oxygen enhancement ratio (OER). So far, only few attempts to include OER in treatment planning for ion beam therapy were made, which are based on the dose averaged LET estimates and do not distinguish among ion species and fractionation schemes. To overcome these limitations, we implemented a new OER model and used it to estimate tumor control in clinical cases. Methods: The model, based on the microdosimetric kinetic model, was benchmarked with in-vitro data from different ions irradiation. It was included in the simulation of treatments of a set of clinical cases (glioblastoma) using p, Li, He, C and O ion beams. Tumor Control Probability (TCP) was estimated as a function of oxygen partial pressure, dose per fraction and primary ion type. Results: The modelized OER was found to be strongly dependent on both LET and ion type, and showed a decreasing OER for increasing dose per fraction with a slope that depends on the LET and ion type, in good agreement with the experimental data. In the clinical cases studied, an increase in TCP by increasing ion charge and dose per fraction (more than 30% variation from p to O for moderate hypoxia) was found. Higher OER decrease rates as function of dose per fraction were found for lighter ions (up to 20% varying from 2 to 8 Gy(RBE)). Conclusions: A novel modeling of the OER that explicitly includes the dependence on ion type and dose per fraction was implemented. The model was exploited to evaluate the impact of hypoxia in ion beam radiotherapy, facilitating the identification of the treatment condition optimality, including fractionation scheme and ion type.

  1. MRI to CT prostate registration for improved targeting in cancer external beam radiotherapy.

    Science.gov (United States)

    Commandeur, Frederic; Simon, Antoine; Mathieu, Romain; Nassef, Mohamed; Ospina, Juan David; Rolland, Yan; Haigron, Pascal; De Crevoisier, Renaud; Acosta, Oscar

    2016-06-16

    External radiotherapy is a major clinical treatment for localized prostate cancer. Currently, computed tomography (CT) is used to delineate the prostate and to plan the radiotherapy treatment. However, CT images suffer from a poor soft tissue contrast and do not allow an accurate organ delineation. On the contrary, Magnetic resonance imaging (MRI) provides rich details and high soft tissue contrast, allowing tumor detection. Thus, the intra-individual propagation of MRI delineations towards the planning CT may improve tumor targeting. In this paper we introduce a new method to propagate MRI prostate delineations to the planning CT. In a first step, a random forest (RF) classification is performed to coarsely detect the prostate in the CT images, yielding a prostate probability membership for each voxel and a prostate hard segmentation. Then the registration is performed using a new similarity metric which maximizes the probability and the collinearity between the normals of the MR existing contour and the contour resulting from the CT classification. A first study on synthetic data was performed to analyze the influence of the metric parameters with different levels of noise. Then, the method was also evaluated on real MR-CT data using manual alignments and intraprostatic fiducial markers and compared to a classically used mutual information (MI) approach. The proposed metric outperformed MI by 7% in terms of Dice score coefficient (DSC), by 3.14 mm the Hausdorff Distance (HD) and 2.13 mm the markers position errors (MPE). Finally, the impact of registration uncertainties on the treatment planning was evaluated, demonstrating the potential advantage of the proposed approach in a clinical setup to define a precise target.

  2. Monte Carlo Commissioning of Low Energy Electron Radiotherapy Beams using NXEGS Software

    Directory of Open Access Journals (Sweden)

    2004-06-01

    Full Text Available This work is a report on the commissioning of low energy electron beams of a medical linear accelerator for Monte Carlo dose calculation using NXEGS software (NXEGS version 1.0.10.0, NX Medical Software, LLC. A unique feature of NXEGS is automated commissioning, a process whereby a combination of analytic and Monte Carlo methods generates beam models from dosimetric data collected in a water phantom. This study uses NXEGS to commission 6, 9, and 12 MeV electron beams of a Varian Clinac 2100C using three applicators with standard inserts. Central axis depth-dose, primary axis and diagonal beam profiles, and output factors are the measurements necessary for commissioning of the code. We present a comparison of measured dose distributions with the distributions generated by NXEGS, using confidence limits on seven measures of error. We find that confidence limits are typically less than 3% or 3 mm, but increase with increasing source to surface distance (SSD and depth at or beyond R50. We also investigate the dependence of NXEGS' performance on the size and composition of data used to commission the program, finding a weak dependence on number of dose profiles in the data set, but finding also that commissioning data need be measured at only two SSDs.

  3. Magnetic fields and beam optics studies of a 250 MeV superconducting proton radiotherapy cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Won [Research Institute and Hospital, National Cancer Center, 809 Madu-dong, Koyang, Kyonggi (Korea, Republic of)], E-mail: jwkim@ncc.re.kr

    2007-11-21

    A 250 MeV superconducting cyclotron for the proton radiation therapy was designed at the Michigan State University (MSU) for use at the Paul Scherrer Institut. This work was based on the conceptual design carried out at the MSU in 1994. The previous design was refined to finalize the magnet configuration and to optimally arrange cyclotron elements for the actual construction. The spiral angle of the pole was reduced, the new hill-edges and valley shims being introduced. The magnetic fields were highly isochronized using a least square fitting routine involving a schematic shimming scheme. The resulting reference field was adequate for the elaborate study of beam optics. The optics simulation predicted that extraction efficiency of above 80% was achievable for a beam with the initial phase width of 20{sup o}. The vertical deflector was investigated located in the central region to control the beam intensity with tracking of beam phase spaces. Some measurement results for the constructed cyclotron were found in a good agreement with those of the optics study.

  4. Patterns of Radiotherapy Practice for Patients With Cervical Cancer in Japan, 2003-2005: Changing Trends in the Pattern of Care Process

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Natsuo, E-mail: ntomita@aichi-cc.jp [Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya (Japan); Toita, Takafumi [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Okinawa (Japan); Kodaira, Takeshi [Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya (Japan); Shinoda, Atsunori [Department of Radiology, Shinshu University School of Medicine, Matsumoto (Japan); Uno, Takashi [Department of Radiology, Graduate School of Medicine, Chiba University, Chiba (Japan); Numasaki, Hodaka; Teshima, Teruki [Department of Medical Physics and Engineering, Graduate School of Medicine, Osaka University, Suita (Japan); Mitsumori, Michihide [Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto (Japan)

    2012-08-01

    Purpose: The patterns of care study (PCS) of radiotherapy for cervical cancer in Japan over the last 10 years was reviewed. Methods and Materials: The Japanese PCS working group analyzed data from 1,200 patients (1995-1997, 591 patients; 1999-2001, 324 patients; 2003-2005, 285 patients) with cervical cancer treated with definitive radiotherapy in Japan. Results: Patients in the 2001-2003 survey were significantly younger than those in the 1999-2001 study (p < 0.0001). Histology, performance status, and International Federation of Gynecology and Obstetrics stage were not significantly different among the three survey periods. Use of combinations of chemotherapy has increased significantly during those periods (1995-1997, 24%; 1999-2001, 33%; 2003-2005, 54%; p < 0.0001). The ratio of patients receiving concurrent chemotherapy has also dramatically increased (1995-1997, 20%; 1999-2001, 54%; 2003-2005, 83%; p < 0.0001). As for external beam radiotherapy (EBRT), the application rate of four-field portals has greatly increased over the three survey periods (1995-1997, 2%; 1999-2001, 7%; 2003-2005, 21%; p < 0.0001). In addition, the use of an appropriate beam energy for EBRT has shown an increase (1995-1997, 67%; 1999-2001, 74%; 2003-2005, 81%; p = 0.064). As for intracavitary brachytherapy (ICBT), an iridium source has become increasingly popular (1995-1997, 27%; 1999-2001, 42%; 2003-2005, 84%; p < 0.0001). Among the three surveys, the ratio of patients receiving ICBT (1995-1997, 77%; 1999-2001, 82%; 2003-2005, 78%) has not changed. Although follow-up was inadequate in each survey, no significant survival differences were observed (p = 0.36), and rates of late Grade 3 or higher toxicity were significantly different (p = 0.016). Conclusions: The Japanese PCS has monitored consistent improvements over the past 10 years in the application of chemotherapy, timing of chemotherapy, and EBRT methods. However, there is still room for improvement, especially in the clinical

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  6. Chest wall radiotherapy with volumetric modulated arcs and the potential role of flattening filter free photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Subramaniam, S.; Thirumalaiswamy, S.; Srinivas, C. [Yashoda Super Specialty Hospital, Hyderabad (IN)] (and others)

    2012-06-15

    The goal of the work was to assess the role of RapidArc treatments in chest wall irradiation after mastectomy and determine the potential benefit of flattening filter free beams. Planning CT scans of 10 women requiring post-mastectomy chest wall radiotherapy were included in the study. A dose of 50 Gy in 2 Gy fractions was prescribed. Organs at risk (OARs) delineated were heart, lungs, contralateral breast, and spinal cord. Dose-volume metrics were defined to quantify the quality of concurrent treatment plans assessing target coverage and sparing of OARs. Plans were designed for conformal 3D therapy (3DCRT) or for RapidArc with double partial arcs (RA). RapidArc plans were optimized for both conventional beams as well as for unflattened beams (RAF). The goal for this planning effort was to cover 100% of the planning target volume (PTV) with {>=} 90% of the prescribed dose and to minimize the volume inside the PTV receiving > 105% of the dose. The mean ipsilateral lung dose was required to be lower than 15 Gy and V{sub 20} {sub Gy} < 22%. Contralateral organ irradiation was required to be kept as low as possible. All techniques met planning objectives for PTV and for lung (3DCRT marginally failed for V{sub 20} {sub Gy}). RA plans showed superiority compared to 3DCRT in the medium to high dose region for the ipsilateral lung. Heart irradiation was minimized by RAF plans with {proportional_to} 4.5 Gy and {proportional_to} 15 Gy reduction in maximum dose compared to RA and 3DCRT, respectively. RAF resulted in superior plans compared to RA with respect to contralateral breast and lung with a reduction of {proportional_to} 1.7 Gy and 1.0 Gy in the respective mean doses. RapidArc treatment resulted in acceptable plan quality with superior ipsilateral tissue sparing compared to traditional techniques. Flattening filter free beams, recently made available for clinical use, might provide further healthy tissue sparing, particularly in contralateral organs, suggesting their

  7. On the feasibility of dose quantification with in-beam PET data in radiotherapy with {sup 12}C and proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Parodi, K.

    2004-11-01

    The physical advantages of light ions in combination with technological advances like intensity controlled raster scanning offer a unique tool for high precision radiotherapy. This is particularly applied to delicate clinical situations of inoperable tumours growing in close proximity to critical organs. The potential benefit of such a high selectivity of ion beam therapy demands the complex and strictly conformal dose delivery to be monitored in-situ and non-invasively in three dimensions. In contrast to conventional photon radiation, light ions exhibit a well defined range which determines the position of the maximum dose delivery in the inhomogeneous tumour target. This requires a monitoring technology along the ion trajectory offering millimetre precision. Additionally, accurate control of the lateral position of the irradiation field within the patient can be a crucial issue for the frequent case of portals passing adjacent to organs at risk. At present, positron emission tomography (PET) represents the only feasible method fulfilling these requirements. For this purpose a dedicated in-beam positron camera has been completely integrated into the experimental heavy ion treatment site at the Gesellschaft fuer Schwerionenforschung (GSI) Darmstadt. This allows to measure the minor amount of {beta}{sup +}-activity produced in nuclear reactions between the projectiles and the target nuclei of the tissue simultaneously to the tumour irradiation. The emitted signal is correlated but not directly proportional to the spatial pattern of the delivered dose. Hence, therapy control is achieved by comparing the measured {beta}{sup +}-activity distribution with a prediction based on the treatment plan and the specific time course of the particular irradiation. (orig.)

  8. Simple methods to reduce patient dose in a Varian cone beam CT system for delivery verification in pelvic radiotherapy.

    Science.gov (United States)

    Roxby, P; Kron, T; Foroudi, F; Haworth, A; Fox, C; Mullen, A; Cramb, J

    2009-10-01

    Cone-beam computed tomography (CBCT) is a three-dimensional imaging modality that has recently become available on linear accelerators for radiotherapy patient position verification. It was the aim of the present study to implement simple strategies for reduction of the dose delivered in a commercial CBCT system. The dose delivered in a CBCT procedure (Varian, half-fan acquisition, 650 projections, 125 kVp) was assessed using a cylindrical Perspex phantom (diameter, 32 cm) with a calibrated Farmer type ionisation chamber. A copper filter (thickness, 0.15 mm) was introduced increasing the half value layer of the beam from 5.5 mm Al to 8 mm Al. Image quality and noise were assessed using an image quality phantom (CatPhan) while the exposure settings per projection were varied from 25 ms/80 mA to 2 ms/2 mA per projection. Using the copper filter reduced the dose to the phantom from approximately 45 mGy to 30 mGy at standard settings (centre/periphery weighting 1/3 to 2/3). Multiple CBCT images were acquired for six patients with pelvic malignancies to compare CBCTs with and without a copper filter. Although the reconstructed image is somewhat noisier with the filter, it features similar contrast in the centre of the patient and was often preferred by the radiation oncologist because of greater image uniformity. The X-ray shutters were adjusted to the minimum size required to obtain the desired image volume for a given patient diameter. The simple methods described here reduce the effective dose to patients undergoing daily CBCT and are easy to implement, and initial evidence suggests that they do not affect the ability to identify soft tissue for the purpose of treatment verification.

  9. The management of carcinoma of the anal canal by external beam radiotherapy, experience in Vancouver 1971-1988

    Energy Technology Data Exchange (ETDEWEB)

    Newman, G. (Bristol Oncology Centre (United Kingdom)); Calverley, D.C.; Acker, B.D.; Manji, M.; Hay, J.; Flores, A.D. (British Columbia Cancer Inst., Vancouver, BC (Canada))

    1992-11-01

    From 1971 to 1988 72 cases of carcinoma of the anal canal were treated by external beam radiotherapy, most commonly by 5000 cGy in 20 fractions given over 4 weeks. The actuarial survival at 5 years was 66% and the disease specific survival 78%. Nine patients had inguinal node metastases at diagnosis; their 5-year disease specific survival was 75%. 63 Patients were inguinal node negative at presentation; their 5-year specific survival was 78%, by UICC 1987 staging: T[sub 1] 71%, T[sub 2] 88%, T[sub 3] 41%, T[sub 4] 42%. 17 Patients developed local recurrence; 10 were suitable for abdominoperineal resection which was successful in 7. The probability of local control was related to T stage. 13 patients were left with a colostomy because of recurrence, 2 had a colostomy for radiation damage and 4 had their local recurrence managed palliatively, without a colostomy. As a result, 53 of the 72 patients (74%) were left with a functional anus. Severe late complications occurred in 6 (8%). (author). 13 refs., 3 figs., 7 tabs.

  10. Postprostatectomy ultrasound-guided transrectal implantation of gold markers for external beam radiotherapy. Technique and complications rate

    Energy Technology Data Exchange (ETDEWEB)

    Langenhuijsen, J.F.; Kiemeney, L.A.L.M.; Witjes, J.A. [Radboud Univ. Nijmegen Medical Center, Nijmegen (Netherlands). Dept. of Urology; Donker, R. [Medical Center Alkmaar (Netherlands). Dept. of Radiation Oncology; McColl, G.M.; Lin, E.N.J.T. van [Radboud Univ. Nijmegen Medical Center, Nijmegen (Netherlands). Dept. of Radiation Oncology

    2013-06-15

    Background and purpose: Postprostatectomy radiotherapy (RT) improves survival in adjuvant and salvage settings. The implantation technique and complications rate of gold markers in the prostate bed for high-precision RT were analyzed. Patients and methods: Patients undergoing postprostatectomy RT for prostate-specific antigen (PSA) relapse or high-risk disease were enrolled in the study. Under transrectal ultrasound guidance, three fine gold markers were implanted in the prostate bed and the technical difficulties of insertion were documented. Patients received our self-designed questionnaires concerning complications and pain. The influence of anticoagulants and coumarins on bleeding was analyzed, as was the effect of potential risk factors on pain. Results: In 77 consecutive patients, failure of marker implantation or marker migration was seen in six cases. Rectal bleeding was reported by 10 patients and 1 had voiding complaints. No macroscopic hematuria persisting for more than 3 days was observed. Other complications included rectal discomfort (n = 2), nausea (n = 1), abdominal discomfort (n = 1), and pain requiring analgesics (n = 4). No major complications were reported. On a 0-10 visual analogue scale (VAS), the mean pain score was 3.7. No clinically significant risk factors for complications were identified. Conclusion: Transrectal implantation of gold markers in the prostate bed is feasible and safe. Alternatives like cone beam computed tomography (CBCT) should be considered, but the advantages of gold marker implantation for high-precision postprostatectomy RT would seem to outweigh the minor risks involved. (orig.)

  11. The effect of beam energy on the quality of IMRT plans for prostate conformal radiotherapy.

    Science.gov (United States)

    de Boer, Steven F; Kumek, Yunus; Jaggernauth, Wainwright; Podgorsak, Matthew B

    2007-04-01

    Three dimensional conformal radiation therapy (3DCRT) for prostate cancer is most commonly delivered with high-energy photons, typically in the range of 10-21 MV. With the advent of Intensity Modulated Radiation Therapy (IMRT), an increase in the number of monitor units (MU) relative to 3DCRT has lead to a concern about secondary malignancies. This risk becomes more relevant at higher photon energies where there is a greater neutron contribution. Subsequently, the majority of IMRT prostate treatments being delivered today are with 6-10 MV photons where neutron production is negligible. However, the absolute risk is small [Hall, E. J. Intensity Modulated Radiation Therapy, Protons, and the Risk of Second Cancers. Int J Radiat Oncol Bio Phys 65, 1-7 (2006); Kry, F. S., Salehpour, M., Followill, D. S., Stovall, M., Kuban, D. A., White, R. A., and Rosen, I. I. The Calculated Risk of Fatal Secondary Malignancies From Intensity Modulated Radiation Therapy. Int J Radiat Oncol Bio Phys 62, 1195-1203 (2005).] and therefore it has been suggested that the use of an 18MV IMRT may achieve better target coverage and normal tissue sparing such that this benefit outweighs the risks. This paper investigates whether 18MV IMRT offer better target coverage and normal tissue sparing. Computed Tomography (CT) image sets of ten prostate cancer patients were acquired and two separate IMRT plans were created for each patient. One plan used 6 MV beams, and the other used 18 MV, both in a coplanar, non-opposed beam geometry. Beam arrangements and optimization constraints were the same for all plans. This work includes a comparison and discussion of the total integral dose, neutron dose conformity index, and total number of MU for plans generated with both energies.

  12. Analysis of ionic mobilities in liquid isooctane with low dose radiotherapy pulsed photon beams

    Science.gov (United States)

    Pardo-Montero, J.; Tegami, S.; Gago-Arias, A.; González-Castaño, D. M.; Holzscheiter, M. H.; Gómez, F.

    2012-09-01

    In this work we present a model of signal temporal development in ionization chambers and we use it to determine ionic mobilities and relative densities of charge carriers in non-ultrapure liquid isooctane using a liquid-filled ionization chamber dosimeter. The detector has been irradiated with a low dose rate, short pulsed photon beam generated with a medical LINAC. Ionic mobilities have been obtained by studying the temporal development of the readout signal and fitting it to a model for low dose rate beams where recombination is negligible. The best fit has been obtained for 3 ionic species with mobilities k1 = (2.22±0.22) × 10-8, k2 = (3.37±0.43) × 10-8, k3 = (19.69±2.59) × 10-8 m2 V-1 s-1 and relative densities n1 = 0.5 (n1 is not a fitting parameter), n2 = 0.23±0.03 and n3 = 0.27±0.03.

  13. Broad-beam three-dimensional irradiation system for heavy-ion radiotherapy at HIMAC

    CERN Document Server

    Futami, Y; Fujita, M; Tomura, H; Higashi, A; Matsufuji, N; Miyahara, N; Endo, M; Kawachi, K

    1999-01-01

    A three-dimensional irradiation system using a broad beam has been installed for heavy-ion cancer therapy at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility. Only the target region is irradiated at the 100% dose level; the dose level at other parts of irradiated tissues is less, using a range shifter, a multileaf collimator and a compensator. The devices are the same as those used in two-dimensional irradiation, except that the setting values of the devices can be dynamically changed during the treatment. The thickness of the absorber and the aperture of the multileaf collimator are dynamically controlled during irradiation, so that the Bragg peak is swept in the depth direction and the Bragg peak outside of the target volume is blocked by the multileaf collimator. The performance of this system was checked by irradiation of a phantom using a 290 MeV/nucleon carbon beam. The dose distribution realized by this three-dimensional irradiation agreed satisfactorily with the planned one.

  14. Enteric-coated, highly standardized cranberry extract reduces risk of UTIs and urinary symptoms during radiotherapy for prostate carcinoma

    Science.gov (United States)

    Bonetta, Alberto; Di Pierro, Francesco

    2012-01-01

    Background Cranberry (Vaccinium macrocarpon) proanthocyanidins can interfere with adhesion of bacteria to uroepithelial cells, potentially preventing lower urinary tract infections (LUTIs). Because LUTIs are a common side effect of external beam radiotherapy (EBRT) for prostate cancer, we evaluated the clinical efficacy of enteric-coated tablets containing highly standardized V. msacrocarpon (ecVM) in this condition. Methods A total of 370 consecutive patients were entered into this study. All patients received intensity-modulated radiotherapy for prostate cancer; 184 patients were also treated with ecVM while 186 served as controls. Cranberry extract therapy started on the simulation day, at which time a bladder catheterization was performed. During EBRT (over 6–7 weeks), all patients underwent weekly examination for urinary tract symptoms, including regular urine cultures during the treatment period. Results Compliance was excellent, with no adverse effects or allergic reactions being observed, apart from gastric pain in two patients. In the cranberry cohort (n = 184), 16 LUTIs (8.7%) were observed, while in the control group (n = 186) 45 LUTIs (24.2%) were recorded. This difference was statistically significant. Furthermore, lower rates of nocturia, urgency, micturition frequency, and dysuria were observed in the group that received cranberry extract. Conclusion Cranberry extracts have been reported to reduce the incidence of LUTIs significantly in women and children. Our data extend these results to patients with prostate cancer undergoing irradiation to the pelvis, who had a significant reduction in LUTIs compared with controls. These results were accompanied by a statistically significant reduction in urinary tract symptoms (dysuria, nocturia, urinary frequency, urgency), suggesting a generally protective effect of cranberry extract on the bladder mucosa. PMID:22977312

  15. Prognostic analysis of uterine cervical cancer treated with postoperative radiotherapy: importance of positive or close parametrial resection margin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yi Jun; Lee, Kyung Ja; Park, Kyung Ran [Dept. of Radiation Oncology, (Korea, Republic of); and others

    2015-06-15

    To analyze prognostic factors for locoregional recurrence (LRR), distant metastasis (DM), and overall survival (OS) in cervical cancer patients who underwent radical hysterectomy followed by postoperative radiotherapy (PORT) in a single institute. Clinicopathologic data of 135 patients with clinical stage IA2 to IIA2 cervical cancer treated with PORT from 2001 to 2012 were reviewed, retrospectively. Postoperative parametrial resection margin (PRM) and vaginal resection margin (VRM) were investigated separately. The median treatment dosage of external beam radiotherapy (EBRT) to the whole pelvis was 50.4 Gy in 1.8 Gy/fraction. High-dose-rate vaginal brachytherapy after EBRT was given to patients with positive or close VRMs. Concurrent platinum-based chemoradiotherapy (CCRT) was administered to 73 patients with positive resection margin, lymph node (LN) metastasis, or direct extension of parametrium. Kaplan-Meier method and log-rank test were used for analyzing LRR, DM, and OS; Cox regression was applied to analyze prognostic factors. The 5-year disease-free survival was 79% and 5-year OS was 91%. In univariate analysis, positive or close PRM, LN metastasis, direct extension of parametrium, lymphovascular invasion, histology of adenocarcinoma, and chemotherapy were related with more DM and poor OS. In multivariate analysis, PRM and LN metastasis remained independent prognostic factors for OS. PORT after radical hysterectomy in uterine cervical cancer showed excellent OS in this study. Positive or close PRM after radical hysterectomy in uterine cervical cancer correlates with poor prognosis even with CCRT. Therefore, additional treatments to improve local control such as radiation boosting need to be considered.

  16. Fifteen symposia on microdosimetry: implications for modern particle-beam cancer radiotherapy

    CERN Document Server

    Wambersie, A; Gueulette, J; Pihet, P

    2015-01-01

    The objective of microdosimetry was, and still is, to identify physical descriptions of the initial physical processes of ionising radiation interacting with biological matter which correlate with observed radiobiological effects with a view to improve the understanding of radiobiological mechanisms and effects. The introduction of therapy with particles starting with fast neutrons followed by negative pions, protons and light ions necessitated the application of biological weighting factors for absorbed dose in order to account for differences of the relative biological effectiveness (RBE). Dedicated radiobiological experiments in therapy beams with mammalian cells and with laboratory animals provided sets of RBE values which are used to evaluate empirical ‘clinical RBE values’. The combination of such experiments with microdosimetric measurements in identical conditions offered the possibility to establish semi-empirical relationships between microdosimetric parameters and results of RBE studies.

  17. SU-E-T-211: Induced Release of Nanocarrier Encapsulated Chemotherapeutic Drugs Using Proton Radiotherapy Beams

    Energy Technology Data Exchange (ETDEWEB)

    Polf, J; Jackson, I [University of Maryland School of Medicine, Baltimore, MD (United States); Ranjan, A; Fernando, R [Oklahoma State University, Stillwater, OK (United States); Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States)

    2014-06-01

    Purpose: The purpose of this work was to develop and validate an open source independent MU dose calculation software for S and S IMRT based in the algorithm proposed by Kung et.al. Methods: Treatment plans were done using Iplan v4.5 BrainLAB TPS and S and S IMRT modality. A 6MV photon beam produced by a Primus linear accelerator equipped with an Optifocus MLC was used. TPS dose calculation algorithms were pencil beam and Monte Carlo. 230 IMRT treatments plans were selected for the study. The software was written under MALTLAB environment. Treatment plans were imported by the software using RTP format. Field fluences were reconstructed adding all segments.The algorithm implemented in the software calculates the dose at a reference point as the sum of primary and scatter dose. The primary dose is obtained by masking the fluence map with a circle of radius 1cm. The scatter dose is obtained through a shaped ring mask around the previous circle with a thickness of 0.5cm; the rings are increased one after another with constant thickness until cover the entire map of influence. The dosimetric parameters Sc, Sp and TPR vary depending on radio, the transmission effect of the MLC, inverse square law and dose profile are used for the calculation. Results: The average difference between measured and independent calculated dose was 0.4% ± 2.2% [−6.8%, 6.4%]. For 91% of the studied plans the difference was less than 3%. The difference between the measured and TPS dose with pencilbeam algorithm was 2.6% ± 1.41% [−2.0%, 5.6%] and Monte Carlo algorithm was 0.4% ± 1.5% [−4.9%, 3.7%]. The differences obtained are comparable to that obtained with the ionization chamber and TPS. Conclusion: The developed software is suitable for use in S and S IMRT dose calculation. This application is open and can be downloading under request.

  18. Validation of an amino-acid-based radionuclide therapy plus external beam radiotherapy in heterotopic glioblastoma models

    Energy Technology Data Exchange (ETDEWEB)

    Israel, Ina [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany); Blass, Georg [Department of Radiotherapy and Radiooncology, Saarland University Medical Center, Homburg (Germany); Reiners, Christoph [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany); Samnick, Samuel, E-mail: samnick_s@klinik.uni-wuerzburg.d [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany)

    2011-05-15

    Background and purpose: Malignant gliomas represent a major therapeutic challenge because no efficient treatment is currently available. p-[{sup 131}I]iodo-L-phenylalanine ([{sup 131}I]IPA) is a glioma avid radiopharmaceutical that demonstrated antiproliferative and tumoricidal effects in gliomas. The present study validated the therapeutic efficiency of [{sup 131}I]IPA combined with external beam radiotherapy in experimental gliomas. Materials and methods: Glioma cells derived from the primary human A1207, T5135, Tx3868 and M059K glioblastoma cell lines or rat F98 glioma cell line were treated with various doses of [{sup 131}I]IPA, external photon irradiation (RT) or combined [{sup 131}I]IPA/RT treatment. Responsiveness of glioma cells to the different therapy modalities was investigated at 24, 48 and 72 h after treatments by trypan blue, WST-1 assay, propidium iodide and bisbenzimide staining as well as by clonogenic assay. In addition, the therapy-induced DNA damage and repair were evaluated using phosphorylated histone H2AX ({gamma}-H2AX). In vivo, the effectiveness of the combination treatment was validated in human Tx3868 and A1207 glioblastoma xenografts in CD1 nu/nu mice and RNU rats. Results: In vitro, the combination treatment resulted in a greater than additive increase in cytotoxic effect in glioma cell lines. Cell survival rate following a treatment with 1.0 {mu}Ci (37 kBq) of [{sup 131}I]IPA amounted to 70%{+-}15% and 60%{+-}10% after 48 and 72 h, respectively, and decreased under 20% after additional RT with 5 Gy. At higher RT doses, cell survival rate decreased below 5%. As a measure of DNA double-strand break, nuclear {gamma}-H2AX foci were determined as a function of time. Within 24 h, the number of {gamma}-H2AX foci per cell was significantly greater after combined modality compared with the individual treatments. In vivo, when combined with RT, the radionuclide therapy with [{sup 131}I]IPA resulted in an extended tumor growth delay, a reduction

  19. Quantification and Assessment of Interfraction Setup Errors Based on Cone Beam CT and Determination of Safety Margins for Radiotherapy.

    Directory of Open Access Journals (Sweden)

    Macarena Cubillos Mesías

    Full Text Available To quantify interfraction patient setup-errors for radiotherapy based on cone-beam computed tomography and suggest safety margins accordingly.Positioning vectors of pre-treatment cone-beam computed tomography for different treatment sites were collected (n = 9504. For each patient group the total average and standard deviation were calculated and the overall mean, systematic and random errors as well as safety margins were determined.The systematic (and random errors in the superior-inferior, left-right and anterior-posterior directions were: for prostate, 2.5(3.0, 2.6(3.9 and 2.9(3.9mm; for prostate bed, 1.7(2.0, 2.2(3.6 and 2.6(3.1mm; for cervix, 2.8(3.4, 2.3(4.6 and 3.2(3.9mm; for rectum, 1.6(3.1, 2.1(2.9 and 2.5(3.8mm; for anal, 1.7(3.7, 2.1(5.1 and 2.5(4.8mm; for head and neck, 1.9(2.3, 1.4(2.0 and 1.7(2.2mm; for brain, 1.0(1.5, 1.1(1.4 and 1.0(1.1mm; and for mediastinum, 3.3(4.6, 2.6(3.7 and 3.5(4.0mm. The CTV-to-PTV margins had the smallest value for brain (3.6, 3.7 and 3.3mm and the largest for mediastinum (11.5, 9.1 and 11.6mm. For pelvic treatments the means (and standard deviations were 7.3 (1.6, 8.5 (0.8 and 9.6 (0.8mm.Systematic and random setup-errors were smaller than 5mm. The largest errors were found for organs with higher motion probability. The suggested safety margins were comparable to published values in previous but often smaller studies.

  20. Oxidative Stress Markers in Prostate Cancer Patients after HDR Brachytherapy Combined with External Beam Radiation

    Directory of Open Access Journals (Sweden)

    Alina Woźniak

    2012-01-01

    Full Text Available Assessment of oxidative stress markers was perfomed in prostate cancer (PCa patients subjected to high-dose brachytherapy (HDR with external beam radiotherapy (EBRT. Sixty men with PCa were subjected to combined two-fraction treatment with HDR (tot. 20 Gy and EBRT (46 Gy. Blood samples were taken before treatment, immediately afterwards, after 1.5–3 months, and approx. 2 years. Control group consisted of 30 healthy men. Erythrocyte glutathione peroxidase activity in the patients was lower than in healthy subjects by 34% (, 50% (, 30% (, and 61% (, respectively, at all periods. No significant differences were found by comparing superoxide dismutase and catalase activity in PCa patients with that of the controls. After 2 years of the end of treatment, the activity of studied enzymes demonstrated a decreasing tendency versus before therapy. Blood plasma thiobarbituric acid reactive substances (TBARS concentration was higher than in the controls at all periods, while erythrocyte TBARS decreased after 2 years to control levels. The results confirm that in the course of PCa, imbalance of oxidant-antioxidant processes occurs. The therapy did not alter the levels of oxidative stress markers, which may prove its applicability. Two years is too short a period to restore the oxidant-antioxidant balance.

  1. Intensity-Modulated Radiotherapy Causes Fewer Side Effects than Three-Dimensional Conformal Radiotherapy When Used in Combination With Brachytherapy for the Treatment of Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Forsythe, Kevin; Blacksburg, Seth [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States); Stone, Nelson [Department of Urology, Mount Sinai School of Medicine, New York, NY (United States); Stock, Richard G., E-mail: richard.stock@moutsinai.org [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States)

    2012-06-01

    Purpose: To measure the benefits of intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3D-CRT) when used in combination with brachytherapy for the treatment of prostate cancer. Methods and Materials: We conducted a retrospective review of all patients with localized prostate cancer who received external-beam radiotherapy (EBRT) in combination with brachytherapy with at least 1 year follow-up (n = 812). Combination therapy consisted of {sup 103}Pd or {sup 125}I implant, followed by a course of EBRT. From 1993 to March 2003 521 patients were treated with 3D-CRT, and from April 2003 to March 2009 291 patients were treated with IMRT. Urinary symptoms were prospectively measured with the International Prostate Symptom Score questionnaire with a single quality of life (QOL) question; rectal bleeding was assessed per the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. The Pearson {chi}{sup 2} test was used to compare toxicities experienced by patients who were treated with either IMRT or 3D-CRT. Logistic regression analyses were also performed to rule out possible confounding factors. Results: Within the first 3 months after treatment, patients treated with 3D-CRT scored their urinary symptoms as follows: 19% mild, 44% moderate, and 37% severe; patients treated with IMRT scored their urinary symptoms as follows: 36% mild, 47% moderate, and 17% severe (p < 0.001). The 3D-CRT patients rated their QOL as follows: 35% positive, 20% neutral, and 45% negative; IMRT patients rated their QOL as follows: 51% positive, 18% neutral, and 31% negative (p < 0.001). After 1 year of follow-up there was no longer any difference in urinary morbidity between the two groups. Logistic regression confirmed the differences in International Prostate Symptom Score and QOL in the acute setting (p < 0.001 for both). Grade {>=}2 rectal bleeding was reported by 11% of 3D

  2. Can volumetric modulated arc therapy with flattening filter free beams play a role in stereotactic body radiotherapy for liver lesions? A volume-based analysis

    Energy Technology Data Exchange (ETDEWEB)

    Reggiori, Giacomo; Mancosu, Pietro; Castiglioni, Simona; Alongi, Filippo; Pellegrini, Chiara; Lobefalo, Francesca; Catalano, Maddalena; Fogliata, Antonella; Arcangeli, Stefano; Navarria, Piera; Cozzi, Luca; Scorsetti, Marta [IRCCS Istituto Clinico Humanitas, 20089 Rozzano (Milano) (Italy); Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); IRCCS Istituto Clinico Humanitas, 20089 Rozzano (Milano) (Italy); Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); IRCCS Istituto Clinico Humanitas, 20089 Rozzano (Milano) (Italy)

    2012-02-15

    Purpose: To compare volumetric modulated arc therapy with flattening filter free (FFF) and flattening filter (FF) beams in patients with hepatic metastases subject to hypofractionated radiotherapy (RT). Methods: A planning study on 13 virtual lesions of increasing volume was performed. Two single arc plans were optimized with the RapidArc technique using either FFF or FF beams. A second planning study was performed on ten patients treated for liver metastases to validate conclusions. In all cases, a dose of 75 Gy in 3 fractions was prescribed to the planning target volume (PTV) and plans were evaluated in terms of coverage, homogeneity, conformity, mean dose to healthy liver and to healthy tissue. For each parameter, results were expressed in relative terms as the percentage ratio between FFF and FF data. Results: In terms of PTV coverage, conformity index favored FFF for targets of intermediate size while FF resulted more suitable for small (<100 cm{sup 3}) and large (>300 cm{sup 3}) targets. Plans optimized with FFF beams resulted in increased sparing of healthy tissue in {approx_equal}85% of cases. Despite the qualitative results, no statistically significant differences were found between FFF and FF results. Plans optimized with un-flattened beams resulted in higher average MU/Gy than plans with FF beams. A remarkable and significant difference was observed in the beam-on time (BOT) needed to deliver plans. The BOT for FF plans was 8.2 {+-} 1.0 min; for FFF plans BOT was 2.2 {+-} 0.2 min. Conclusions: RapidArc plans optimized using FFF were dosimetrically equivalent to those optimized using FF beams, showing the feasibility of SBRT treatments with FFF beams. Some improvement in healthy tissue sparing was observed when using the FFF modality due to the different beam's profile. The main advantage was a considerable reduction of beam-on time, relevant for SBRT techniques.

  3. Dosimetric comparison of a 6-MV flattening-filter and a flattening-filter-free beam for lung stereotactic ablative radiotherapy treatment

    Science.gov (United States)

    Kim, Yon-Lae; Chung, Jin-Beom; Kim, Jae-Sung; Lee, Jeong-Woo; Kim, Jin-Young; Kang, Sang-Won; Suh, Tae-Suk

    2015-11-01

    The purpose of this study was to test the feasibility of clinical usage of a flattening-filter-free (FFF) beam for treatment with lung stereotactic ablative radiotherapy (SABR). Ten patients were treated with SABR and a 6-MV FFF beam for this study. All plans using volumetric modulated arc therapy (VMAT) were optimized in the Eclipse treatment planning system (TPS) by using the Acuros XB (AXB) dose calculation algorithm and were delivered by using a Varian TrueBeam ™ linear accelerator equipped with a high-definition (HD) multi-leaf collimator. The prescription dose used was 48 Gy in 4 fractions. In order to compare the plan using a conventional 6-MV flattening-filter (FF) beam, the SABR plan was recalculated under the condition of the same beam settings used in the plan employing the 6-MV FFF beam. All dose distributions were calculated by using Acuros XB (AXB, version 11) and a 2.5-mm isotropic dose grid. The cumulative dosevolume histograms (DVH) for the planning target volume (PTV) and all organs at risk (OARs) were analyzed. Technical parameters, such as total monitor units (MUs) and the delivery time, were also recorded and assessed. All plans for target volumes met the planning objectives for the PTV ( i.e., V95% > 95%) and the maximum dose ( i.e., Dmax marked reduction (52.97%) in the treatment delivery time. The SABR plan with a FFF beam required a larger number of MUs than the plan with the FF beam, and the mean difference in MUs was 4.65%. This study demonstrated that the use of the FFF beam for lung SABR plan provided better treatment efficiency relative to 6-MV FF beam. This strategy should be particularly beneficial for high dose conformity to the lung and decreased intra-fraction movements because of the shorter treatment delivery time. Future studies are necessary to assess the clinical outcome and the toxicity.

  4. Definition of stereotactic body radiotherapy. Principles and practice for the treatment of stage I non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Guckenberger, M.; Sauer, O. [University of Wuerzburg, Department of Radiation Oncology, Wuerzburg (Germany); Andratschke, N. [University of Rostock, Department of Radiotherapy and Radiation Oncology, Rostock (Germany); Alheit, H. [Distler Radiation Oncology, Bautzen/Pirna (Germany); Holy, R. [RWTH Aachen University, Department of Radiation Oncology, Aachen (Germany); Moustakis, C. [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Nestle, U. [University of Freiburg, Department of Radiation Oncology, Freiburg (Germany)

    2014-01-15

    This report from the Stereotactic Radiotherapy Working Group of the German Society of Radiation Oncology (Deutschen Gesellschaft fuer Radioonkologie, DEGRO) provides a definition of stereotactic body radiotherapy (SBRT) that agrees with that of other international societies. SBRT is defined as a method of external beam radiotherapy (EBRT) that accurately delivers a high irradiation dose to an extracranial target in one or few treatment fractions. Detailed recommendations concerning the principles and practice of SBRT for early stage non-small cell lung cancer (NSCLC) are given. These cover the entire treatment process; from patient selection, staging, treatment planning and delivery to follow-up. SBRT was identified as the method of choice when compared to best supportive care (BSC), conventionally fractionated radiotherapy and radiofrequency ablation. Based on current evidence, SBRT appears to be on a par with sublobar resection and is an effective treatment option in operable patients who refuse lobectomy. (orig.) [German] Die Arbeitsgruppe ''Stereotaktische Radiotherapie'' der Deutschen Gesellschaft fuer Radioonkologie (DEGRO) erarbeitete eine Definition der Koerperstereotaxie (SBRT), die sich an vorhandene internationale Definitionen anlehnt: Die SBRT ist eine Form der perkutanen Strahlentherapie, die mit hoher Praezision eine hohe Bestrahlungsdosis in einer oder wenigen Bestrahlungsfraktionen in einem extrakraniellen Zielvolumen appliziert. Zur Praxis der SBRT beim nichtkleinzelligen Bronchialkarzinom (NSCLC) im fruehen Stadium werden detaillierte Empfehlungen gegeben, die den gesamten Ablauf der Behandlung von der Indikationsstellung, Staging, Behandlungsplanung und Applikation sowie Nachsorge umfassen. Die Koerperstereotaxie wurde als Methode der Wahl im Vergleich zu Best Supportive Care, zur konventionell fraktionierten Strahlentherapie sowie zur Radiofrequenzablation identifiziert. Die Ergebnisse nach SBRT und sublobaerer Resektion

  5. Increasing Use of Dose-Escalated External Beam Radiation Therapy for Men With Nonmetastatic Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Swisher-McClure, Samuel, E-mail: Swisher-Mcclure@uphs.upenn.edu [Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States); Leonard Davis Institute of Health Economics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States); Mitra, Nandita; Woo, Kaitlin [Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Smaldone, Marc; Uzzo, Robert [Division of Urologic Oncology, Department of Surgery, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA (United States); Bekelman, Justin E. [Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States); Leonard Davis Institute of Health Economics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States); Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2014-05-01

    Purpose: To examine recent practice patterns, using a large national cancer registry, to understand the extent to which dose-escalated external beam radiation therapy (EBRT) has been incorporated into routine clinical practice for men with prostate cancer. Methods and Materials: We conducted a retrospective observational cohort study using the National Cancer Data Base, a nationwide oncology outcomes database in the United States. We identified 98,755 men diagnosed with nonmetastatic prostate cancer between 2006 and 2011 who received definitive EBRT and classified patients into National Comprehensive Cancer Network (NCCN) risk groups. We defined dose-escalated EBRT as total prescribed dose of ≥75.6 Gy. Using multivariable logistic regression, we examined the association of patient, clinical, and demographic characteristics with the use of dose-escalated EBRT. Results: Overall, 81.6% of men received dose-escalated EBRT during the study period. The use of dose-escalated EBRT did not vary substantially by NCCN risk group. Use of dose-escalated EBRT increased from 70.7% of patients receiving treatment in 2006 to 89.8% of patients receiving treatment in 2011. On multivariable analysis, year of diagnosis and use of intensity modulated radiation therapy were significantly associated with receipt of dose-escalated EBRT. Conclusions: Our study results indicate that dose-escalated EBRT has been widely adopted by radiation oncologists treating prostate cancer in the United States. The proportion of patients receiving dose-escalated EBRT increased nearly 20% between 2006 and 2011. We observed high utilization rates of dose-escalated EBRT within all disease risk groups. Adoption of intensity modulated radiation therapy was strongly associated with use of dose-escalated treatment.

  6. Percentage of Cancer Volume in Biopsy Cores Is Prognostic for Prostate Cancer Death and Overall Survival in Patients Treated With Dose-Escalated External Beam Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Vance, Sean M.; Stenmark, Matthew H.; Blas, Kevin; Halverson, Schulyer [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Hamstra, Daniel A., E-mail: dhamm@umich.edu [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Feng, Felix Y. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Department of Radiation Oncology, Veterans Affairs Medical Center, Ann Arbor, Michigan (United States)

    2012-07-01

    Purpose: To investigate the prognostic utility of the percentage of cancer volume (PCV) in needle biopsy specimens for prostate cancer patients treated with dose-escalated external beam radiotherapy. Methods and Materials: The outcomes were analyzed for 599 men treated for localized prostate cancer with external beam radiotherapy to a minimal planning target volume dose of 75 Gy (range, 75-79.2). We assessed the effect of PCV and the pretreatment and treatment-related factors on the freedom from biochemical failure, freedom from metastasis, cause-specific survival, and overall survival. Results: The median number of biopsy cores was 7 (interquartile range, 6-12), median PCV was 10% (interquartile range, 2.5-25%), and median follow-up was 62 months. The PCV correlated with the National Comprehensive Cancer Network risk group and individual risk features, including T stage, prostate-specific antigen level, Gleason score, and percentage of positive biopsy cores. On log-rank analysis, the PCV stratified by quartile was prognostic for all endpoints, including overall survival. In addition, the PCV was a stronger prognostic factor than the percentage of positive biopsy cores when the two metrics were analyzed together. On multivariate analysis, the PCV predicted a worse outcome for all endpoints, including freedom from biochemical failure, (hazard ratio, 1.9; p = .0035), freedom from metastasis (hazard ratio, 1.7, p = .09), cause-specific survival (hazard ratio, 3.9, p = .014), and overall survival (hazard ratio, 1.8, p = .02). Conclusions: For patients treated with dose-escalated external beam radiotherapy, the volume of cancer in the biopsy specimen adds prognostic value for clinically relevant endpoints, particularly in intermediate- and high-risk patients. Although the PCV determination is more arduous than the percentage of positive biopsy cores, it provides superior risk stratification.

  7. SU-E-T-206: Improving Radiotherapy Toxicity Based On Artificial Neural Network (ANN) for Head and Neck Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Daniel D; Wernicke, A Gabriella; Nori, Dattatreyudu; Chao, KSC; Parashar, Bhupesh; Chang, Jenghwa [Weill Cornell Medical College, NY, NY (United States)

    2014-06-01

    Purpose/Objective(s): The aim of this study is to build the estimator of toxicity using artificial neural network (ANN) for head and neck cancer patients Materials/Methods: An ANN can combine variables into a predictive model during training and considered all possible correlations of variables. We constructed an ANN based on the data from 73 patients with advanced H and N cancer treated with external beam radiotherapy and/or chemotherapy at our institution. For the toxicity estimator we defined input data including age, sex, site, stage, pathology, status of chemo, technique of external beam radiation therapy (EBRT), length of treatment, dose of EBRT, status of post operation, length of follow-up, the status of local recurrences and distant metastasis. These data were digitized based on the significance and fed to the ANN as input nodes. We used 20 hidden nodes (for the 13 input nodes) to take care of the correlations of input nodes. For training ANN, we divided data into three subsets such as training set, validation set and test set. Finally, we built the estimator for the toxicity from ANN output. Results: We used 13 input variables including the status of local recurrences and distant metastasis and 20 hidden nodes for correlations. 59 patients for training set, 7 patients for validation set and 7 patients for test set and fed the inputs to Matlab neural network fitting tool. We trained the data within 15% of errors of outcome. In the end we have the toxicity estimation with 74% of accuracy. Conclusion: We proved in principle that ANN can be a very useful tool for predicting the RT outcomes for high risk H and N patients. Currently we are improving the results using cross validation.

  8. Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, Uros; Herk, Marcel van; Ploeger, Lennert S.; Sonke, Jan-Jakob, E-mail: j.sonke@nki.nl [Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam 1066 CX (Netherlands)

    2014-06-15

    Purpose: Medical linear accelerator mounted cone beam CT (CBCT) scanner provides useful soft tissue contrast for purposes of image guidance in radiotherapy. The presence of extensive scattered radiation has a negative effect on soft tissue visibility and uniformity of CBCT scans. Antiscatter grids (ASG) are used in the field of diagnostic radiography to mitigate the scatter. They usually do increase the contrast of the scan, but simultaneously increase the noise. Therefore, and considering other scatter mitigation mechanisms present in a CBCT scanner, the applicability of ASGs with aluminum interspacing for a wide range of imaging conditions has been inconclusive in previous studies. In recent years, grids using fiber interspacers have appeared, providing grids with higher scatter rejection while maintaining reasonable transmission of primary radiation. The purpose of this study was to evaluate the impact of one such grid on CBCT image quality. Methods: The grid used (Philips Medical Systems) had ratio of 21:1, frequency 36 lp/cm, and nominal selectivity of 11.9. It was mounted on the kV flat panel detector of an Elekta Synergy linear accelerator and tested in a phantom and a clinical study. Due to the flex of the linac and presence of gridline artifacts an angle dependent gain correction algorithm was devised to mitigate resulting artifacts. Scan reconstruction was performed using XVI4.5 augmented with inhouse developed image lag correction and Hounsfield unit calibration. To determine the necessary parameters for Hounsfield unit calibration and software scatter correction parameters, the Catphan 600 (The Phantom Laboratory) phantom was used. Image quality parameters were evaluated using CIRS CBCT Image Quality and Electron Density Phantom (CIRS) in two different geometries: one modeling head and neck and other pelvic region. Phantoms were acquired with and without the grid and reconstructed with and without software correction which was adapted for the different

  9. MRI-guided prostate adaptive radiotherapy – A systematic reviewMRI-linac and prostate motion review

    NARCIS (Netherlands)

    McPartlin, A. J.; Li, X. A.; Kershaw, L. E.; Heide, U.; Kerkmeijer, L.; Lawton, C.; Mahmood, U.; Pos, F.; van As, N.; van Herk, M.; Vesprini, D.; van der Voort van Zyp, J.; Tree, A.; Choudhury, A.

    2016-01-01

    Dose escalated radiotherapy improves outcomes for men with prostate cancer. A plateau for benefit from dose escalation using EBRT may not have been reached for some patients with higher risk disease. The use of increasingly conformal techniques, such as step and shoot IMRT or more recently VMAT, has

  10. COMPARATIVE STUDY OF WEEKLY VERSUS THREE WEEKLY CISPLATIN IN ADVANCED CASES OF CARCINOMA CERVIX ALONG WITH RADIOTHERAPY

    Directory of Open Access Journals (Sweden)

    Preety

    2015-10-01

    Full Text Available : OBJECTIVE: To determine the clinical response and compliance of patients with external radiation therapy with concomitant weekly inj. CISPLATIN (30mg/m2 versus external radiation therapy with three weekly inj.CISPLATIN (100mg/m2. MATERIALS & METHODS: This prospective study was conducted in the Department of Radiation oncology, GOVT. CANCER HOSPITAL. M.G.M. MEDICAL COLLEGE INDORE (M. P. A total of 50 patients were enrolled in study from April 2013 to October 2013 after obtaining written and informed consent. The patients were randomized into two arms. Arm 1- Concurrent weekly cisplatin with Radiotherapy. Arm 2 - Concurrent 3 Weekly Cisplatin with Radiotherapy. All the patients received external beam radiotherapy (EBRT along with 2-3 sittings of intracavitary radiotherapy (ICR with concurrent weekly/ 3 weekly cisplatin. All the patients were simulated in supine position with proper immobilisation. Pelvic EBRT was given using COBALT 60 THERATRON 780C by two parallel opposed AP-PA portals or by four field techniques. A mid plane dose of 46 Gy 20#. RESULTS: out of 25 patients, 19 patients from Arm A and 21 from Arm B had a complete response to treatment, whereas partial and progressive diseases responses were not observed in either of the patients of Arm A and Arm B. On the other hand 12 to 8 percent patients had a stable disease. However, from the whole lot, only 2(8% patients of Arm B had a recurrence of the diseases. Statistically the responses to the different treatment plans on the patients in Arm A and Arm B did not differ significantly from each other. CONCLUSION: this study showed that tri-weekly cispiatin 100mg/m2 concurrent with radiation is feasible and more effective than the conventional weekly cispiatin 40mg/m2- based regimen in achieving local control of the disease at 1 month follow up, however this difference was not sustained over prolonged follow-up. Longer follow-up is required to assess the delayed toxicity, overall survival

  11. SU-E-T-591: Optimizing the Flattening Filter Free Beam Selection in RapidArc-Based Stereotactic Body Radiotherapy for Stage I Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B-T; Lu, J-Y [Cancer Hospital of Shantou University Medical College, Shantou (China)

    2015-06-15

    Purpose: To optimize the flattening filter free (FFF) beam energy selection in stereotactic body radiotherapy (SBRT) treatment for stage I lung cancer with different fraction schemes. Methods: Twelve patients suffering from stage I lung cancer were enrolled in this study. Plans were designed using 6XFFF and 10XFFF beams with the most widely used fraction schemes of 4*12 Gy, 3*18 Gy and 1*34 Gy, respectively. The plan quality was appraised in terms of planning target volume (PTV) coverage, conformity of the prescribed dose (CI100%), intermediate dose spillage (R50% and D2cm), organs at risk (OARs) sparing and beam-on time. Results: The 10XFFF beam predicted 1% higher maximum, mean dose to the PTV and 4–5% higher R50% compared with the 6XFFF beam in the three fraction schemes, whereas the CI100% and D2cm was similar. Most importantly, the 6XFFF beam exhibited 3–10% lower dose to all the OARs. However, the 10XFFF beam reduced the beam-on time by 31.9±7.2%, 38.7±2.8% and 43.6±4.0% compared with the 6XFFF beam in the 4*12 Gy, 3*18 Gy and 1*34 Gy schemes, respectively. Beam-on time was 2.2±0.2 vs 1.5±0.1, 3.3±0.9 vs 2.0±0.5 and 6.3±0.9 vs 3.5±0.4 minutes for the 6XFFF and 10XFFF one in the three fraction schemes. Conclusion: The 6XFFF beam obtains better OARs sparing in SBRT treatment for stage I lung cancer, but the 10XFFF one provides improved treatment efficiency. To balance the OARs sparing and intrafractional variation as a function of prolonged treatment time, the authors recommend to use the 6XFFF beam in the 4*12 Gy and 3*18 Gy schemes for better OARs sparing. However, for the 1*34 Gy scheme, the 10XFFF beam is recommended to achieve improved treatment efficiency.

  12. Single-fraction high-dose-rate brachytherapy using real-time transrectal ultrasound based planning in combination with external beam radiotherapy for prostate cancer: dosimetrics and early clinical results

    Science.gov (United States)

    Lauche, Olivier; Delouya, Guila; Taussky, Daniel; Menard, Cynthia; Béliveau-Nadeau, Dominic; Hervieux, Yannick; Larouche, Renée

    2016-01-01

    Purpose To validate the feasibility of a single-fraction high-dose-rate brachytherapy (HDRBT) boost for prostate cancer using real-time transrectal ultrasound (TRUS) based planning. Material and methods From August 2012 to September 2015, 126 patients underwent a single-fraction HDRBT boost of 15 Gy using real-time TRUS based planning. External beam radiation therapy (EBRT) (37.5 Gy/15 fractions, 44 Gy/22 fractions, or 45 Gy/25 fractions) was performed before (31%) or after (69%) HDRBT boost. Genito-urinary (GU) and gastro-intestinal (GI) toxicity were assessed 4 and 12 months after the end of combined treatment using the international prostate symptom score scale (IPSS) and the common terminology criteria for adverse events (CTCAE) v3.0. Results All dose-planning objectives were achieved in 90% of patients. Prostate D90 ≥ 105% and ≤ 115% was achieved in 99% of patients, prostate V150 ≤ 40% in 99%, prostate V200 < 11% in 96%, urethra D10 < 120% for 99%, urethra V125 = 0% in 100%, and rectal V75 < 1 cc in 93% of patients. Median IPSS score was 4 at baseline and did not change at 4 and 12 months after combined treatment. No patients developed ≥ grade 2 GI toxicity. With a median follow-up of 10 months, only two patients experienced biochemical failure. Among patients who didn't receive ADT, cumulative percentage of patients with PSA ≤ 1 ng/ml at 4 and 18 months was respectively 23% and 66%. Conclusions Single-fraction HDRBT boost of 15 Gy using real-time TRUS based planning achieves consistently high dosimetry quality. In combination with EBRT, toxicity outcomes appear promising. A longer follow-up is needed to assess long-term outcome and toxicities. PMID:27257413

  13. Cone-beam CT-guided radiotherapy in the management of lung cancer. Diagnostic and therapeutic value

    Energy Technology Data Exchange (ETDEWEB)

    Elsayad, Khaled; Kriz, Jan; Reinartz, Gabriele; Scobioala, Sergiu; Ernst, Iris; Haverkamp, Uwe; Eich, Hans Theodor [University Hospital of Muenster, Department of Radiation Oncology, Muenster (Germany)

    2016-02-15

    Recent studies have demonstrated an increase in the necessity of adaptive planning over the course of lung cancer radiation therapy (RT) treatment. In this study, we evaluated intrathoracic changes detected by cone-beam CT (CBCT) in lung cancer patients during RT. A total of 71 lung cancer patients treated with fractionated CBCT-guided RT were evaluated. Intrathoracic changes and plan adaptation priority (AP) scores were compared between small cell lung cancer (SCLC, n = 13) and non-small cell lung cancer (NSCLC, n = 58) patients. The median cumulative radiation dose administered was 54 Gy (range 30-72 Gy) and the median fraction dose was 1.8 Gy (range 1.8-3.0 Gy). All patients were subjected to a CBCT scan at least weekly (range 1-5/week). We observed intrathoracic changes in 83 % of the patients over the course of RT [58 % (41/71) regression, 17 % (12/71) progression, 20 % (14/71) atelectasis, 25 % (18/71) pleural effusion, 13 % (9/71) infiltrative changes, and 10 % (7/71) anatomical shift]. Nearly half, 45 % (32/71), of the patients had one intrathoracic soft tissue change, 22.5 % (16/71) had two, and three or more changes were observed in 15.5 % (11/71) of the patients. Plan modifications were performed in 60 % (43/71) of the patients. Visual volume reduction did correlate with the number of CBCT scans acquired (r = 0.313, p = 0.046) and with the timing of chemotherapy administration (r = 0.385, p = 0.013). Weekly CBCT monitoring provides an adaptation advantage in patients with lung cancer. In this study, the monitoring allowed for plan adaptations due to tumor volume changes and to other anatomical changes. (orig.) [German] Neuere Studien haben eine zunehmende Notwendigkeit der adaptiven Bestrahlungsplanung im Verlauf der Bestrahlungsserie bei Patienten mit Lungenkrebs nachgewiesen. In der vorliegenden Studie haben wir intrathorakale Aenderungen mittels Cone-beam-CT (CBCT) bei Lungenkrebspatienten waehrend der Radiotherapie (RT) analysiert. Analysiert wurden

  14. Pretreatment Endorectal Coil Magnetic Resonance Imaging Findings Predict Biochemical Tumor Control in Prostate Cancer Patients Treated With Combination Brachytherapy and External-Beam Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Riaz, Nadeem [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Afaq, Asim; Akin, Oguz [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Pei Xin; Kollmeier, Marisa A.; Cox, Brett [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Hricak, Hedvig [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-11-01

    Purpose: To investigate the utility of endorectal coil magenetic resonance imaging (eMRI) in predicting biochemical relapse in prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Methods and Materials: Between 2000 and 2008, 279 men with intermediate- or high-risk prostate cancer underwent eMRI of their prostate before receiving brachytherapy and supplemental intensity-modulated radiotherapy. Endorectal coil MRI was performed before treatment and retrospectively reviewed by two radiologists experienced in genitourinary MRI. Image-based variables, including tumor diameter, location, number of sextants involved, and the presence of extracapsular extension (ECE), were incorporated with other established clinical variables to predict biochemical control outcomes. The median follow-up was 49 months (range, 1-13 years). Results: The 5-year biochemical relapse-free survival for the cohort was 92%. Clinical findings predicting recurrence on univariate analysis included Gleason score (hazard ratio [HR] 3.6, p = 0.001), PSA (HR 1.04, p = 0.005), and National Comprehensive Cancer Network risk group (HR 4.1, p = 0.002). Clinical T stage and the use of androgen deprivation therapy were not correlated with biochemical failure. Imaging findings on univariate analysis associated with relapse included ECE on MRI (HR 3.79, p = 0.003), tumor size (HR 2.58, p = 0.04), and T stage (HR 1.71, p = 0.004). On multivariate analysis incorporating both clinical and imaging findings, only ECE on MRI and Gleason score were independent predictors of recurrence. Conclusions: Pretreatment eMRI findings predict for biochemical recurrence in intermediate- and high-risk prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Gleason score and the presence of ECE on MRI were the only significant predictors of biochemical relapse in this group of patients.

  15. Evaluation of the effect of tooth and dental restoration material on electron dose distribution and production of photon contamination in electron beam radiotherapy.

    Science.gov (United States)

    Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Akbari, Fatemeh; Mehrpouyan, Mohammad; Sobhkhiz Sabet, Leila

    2016-03-01

    The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron beams of a Siemens Primus linac. MCNPX Monte Carlo code was utilized and a 10 × 10 cm(2) applicator was simulated in the cases of tooth and combinations of tooth and Ceramco C3 ceramic veneer, tooth and Eclipse alloy and tooth and amalgam restoration materials in a soft tissue phantom. The relative electron and photon contamination doses were calculated for these materials. The presence of tooth and dental restoration material changed the electron dose distribution and photon contamination in phantom, depending on the type of the restoration material and electron beam's energy. The maximum relative electron dose was 1.07 in the presence of tooth including amalgam for 14 MeV electron beam. When 100.00 cGy was prescribed for the reference point, the maximum absolute electron dose was 105.10 cGy in the presence of amalgam for 12 MeV electron beam and the maximum absolute photon contamination dose was 376.67 μGy for tooth in 14 MeV electron beam. The change in electron dose distribution should be considered in treatment planning, when teeth are irradiated in electron beam radiotherapy. If treatment planning can be performed in such a way that the teeth are excluded from primary irradiation, the potential errors in dose delivery to the tumour and normal tissues can be avoided.

  16. Geometrical determinations of IMRT photon pencil-beam path in radiotherapy wedges and limit divergence angle with the Anisotropic Analytic Algorithm (AAA

    Directory of Open Access Journals (Sweden)

    Francisco Casesnoves

    2014-08-01

    Full Text Available Purpose: Static wedge filters (WF are commonly used in radiation therapy, forward and/or inverse planning. We calculated the exact 2D/3D geometrical pathway of the photon-beam through the usual alloy WF, in order to get a better dose related to the beam intensity attenuation factor(s, after the beam has passed through the WF. The objective was to provide general formulation into the Anisotropic Analytical Algorithm (AAA model coordinates system (depending on collimator/wedge angles that also can be applied to other models. Additionally, second purpose of this study was to develop integral formulation for 3D wedge exponential factor with statistical approximations, with introduction for the limit angle/conformal wedge.Methods: The radiotherapy model used to develop this mathematical task is the classical superposition-convolution algorithm, AAA (developed by Ulmer and Harder. We worked with optimal geometrical approximations to make the computational IMRT calculations quicker/reduce the planning-system time. Analytic geometry/computational-techniques to carry out simulations (for standard wedges are detailed/developed sharply. Integral developments/integral-statistical approximations are explained. Beam-divergence limit Angle for optimal wedge filtration formulas is calculated/sketched, with geometrical approximations. Fundamental trigonometry is used for this purpose.Results: Extent simulation tables for WF of 15º, 30º, 45º, and 60º are shown with errors. As a result, it is possible to determine the best individual treatment dose distribution for each patient. We presented these basic simulations/numerical examples for standard manufacturing WF of straight sloping surface, to check the accuracy/errors of the calculations. Simulations results give low RMS/Relative Error values (formulated for WF of 15º, 30º, 45º, and 60º.Conclusion: We obtained a series of formulas of analytic geometry for WF that can be applied for any particular dose

  17. Nanoparticle-guided radiotherapy

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention relates to a method and nano-sized particles for image guided radiotherapy (IGRT) of a target tissue. More specifically, the invention relates to nano-sized particles comprising X-ray-imaging contrast agents in solid form with the ability to block x-rays, allowing for simult...... for simultaneous or integrated external beam radiotherapy and imaging, e.g., using computed tomography (CT)....

  18. Evaluation of the dosimetric impact of applying flattening filter-free beams in intensity-modulated radiotherapy for early-stage upper thoracic carcinoma of oesophagus

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wuzhe; Lin, Zhixiong; Yang, Zhining; Fang, Weisheng; Lai, Peibo; Lu, Jiayang [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong (China); Wu, Vincent WC, E-mail: vincent.wu@polyu.edu.hk [Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong (China)

    2015-06-15

    Flattening filter-free (FFF) radiation beams have recently become clinically available on modern linear accelerators in radiation therapy. This study aimed to evaluate the dosimetric impact of using FFF beams in intensity-modulated radiotherapy (IMRT) for early-stage upper thoracic oesophageal cancer. Eleven patients with primary stage upper thoracic oesophageal cancer were recruited. For each patient, two IMRT plans were computed using conventional beams (Con-P) and FFF beams (FFF-P), respectively. Both plans employed a five-beam arrangement and were prescribed with 64 Gy to (planning target volume) PTV1 and 54 Gy to PTV2 in 32 fractions using 6 MV photons. The dose parameters of the target volumes and organs at risks (OARs), and treatment parameters including the monitor units (MU) and treatment time (TT) for Con-P and FFF-P were recorded and compared. The mean D{sub 5} of PTV1 and PTV2 were higher in FFF-P than Con-P by 0.4 Gy and 0.3 Gy, respectively. For the OARs, all the dose parameters did not show significant difference between the two plans except the mean V{sub 5} and V{sub 10} of the lung in which the FFF-P was lower (46.7% vs. 47.3% and 39.1% vs. 39.6%, respectively). FFF-P required 54% more MU but 18.4% less irradiation time when compared to Con-P. The target volume and OARs dose distributions between the two plans were comparable. However, FFF-P was more effective in sparing the lung from low dose and reduced the mean TT compared with Con-P. Long-term clinical studies are suggested to evaluate the radiobiological effects of FFF beams.

  19. Radiotherapy of cutaneous lymphomas; Radiotherapie des lymphomes cutanes

    Energy Technology Data Exchange (ETDEWEB)

    Kirova, Y.M.; Piedbois, Y.; Pan, Q.; Guo, J.P.; Le Bourgeois, J.P. [Hopital Henri-Mondor, 94 - Creteil (France). Dept. de cancerologie

    1999-03-01

    Radiotherapy plays an important role in the treatment of cutaneous lymphomas. In the treatment of Mycosis fungoides, total skin electron beam radiation therapy is efficient for patients with limited and superficial forms of the disease. Radiotherapy is also efficient for the locally advanced forms of non-epidermo-tropic lymphomas. The palliative radiotherapy is indicated for advanced, nodular and treatment resistant forms of cutaneous lymphomas and for voluminous lymphadenopathies. (authors)

  20. Adaptive Motion Compensation in Radiotherapy

    CERN Document Server

    Murphy, Martin J

    2011-01-01

    External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

  1. Effects of beam interruption time on tumor control probability in single-fractionated carbon-ion radiotherapy for non-small cell lung cancer

    Science.gov (United States)

    Inaniwa, T.; Kanematsu, N.; Suzuki, M.; Hawkins, R. B.

    2015-05-01

    Carbon-ion radiotherapy treatment plans are designed on the assumption that the beams are delivered instantaneously, irrespective of actual dose-delivery time structure in a treatment session. As the beam lines are fixed in the vertical and horizontal directions at our facility, beam delivery is interrupted in multi-field treatment due to the necessity of patient repositioning within the fields. Single-fractionated treatment for non-small cell lung cancer (NSCLC) is such a case, in which four treatment fields in multiple directions are delivered in one session with patient repositioning during the session. The purpose of this study was to investigate the effects of the period of dose delivery, including interruptions due to patient repositioning, on tumor control probability (TCP) of NSCLC. All clinical doses were weighted by relative biological effectiveness (RBE) evaluated for instantaneous irradiation. The rate equations defined in the microdosimetric kinetic model (MKM) for primary lesions induced in DNA were applied to the single-fractionated treatment of NSCLC. Treatment plans were made for an NSCLC case for various prescribed doses ranging from 25 to 50 Gy (RBE), on the assumption of instantaneous beam delivery. These plans were recalculated by varying the interruption time τ ranging from 0 to 120 min between the second and third fields for continuous irradiations of 3 min per field based on the MKM. The curative doses that would result in a TCP of 90% were deduced for the respective interruption times. The curative dose was 34.5 Gy (RBE) for instantaneous irradiation and 36.6 Gy (RBE), 39.2 Gy (RBE), 41.2 Gy (RBE), 43.3 Gy (RBE) and 44.4 Gy (RBE) for τ = 0 min, 15 min, 30 min, 60 min and 120 min, respectively. The realistic biological effectiveness of therapeutic carbon-ion beam decreased with increasing interruption time. These data suggest that the curative dose can increase by 20% or more compared to the planned dose if the

  2. Comparison of Dosimetric Performance among Commercial Quality Assurance Systems for Verifying Pretreatment Plans of Stereotactic Body Radiotherapy Using Flattening-Filter-Free Beams

    Science.gov (United States)

    2016-01-01

    The purpose of this study was to compare the performance of different commercial quality assurance (QA) systems for the pretreatment verification plan of stereotactic body radiotherapy (SBRT) with volumetric arc therapy (VMAT) technique using a flattening-filter-free beam. The verification for 20 pretreatment cancer patients (seven lung, six spine, and seven prostate cancers) were tested using three QA systems (EBT3 film, I’mRT MatriXX array, and MapCHECK). All the SBRT-VMAT plans were optimized in the Eclipse (version 11.0.34) treatment planning system (TPS) using the Acuros XB dose calculation algorithm and were delivered to the Varian TrueBeam® accelerator equipped with a high-definition multileaf collimator. Gamma agreement evaluation was analyzed with the criteria of 2% dose difference and 2 mm distance to agreement (2%/2 mm) or 3%/3 mm. The highest passing rate (99.1% for 3%/3 mm) was observed on the MapCHECK system while the lowest passing rate was obtained on the film. The pretreatment verification results depend on the QA systems, treatment sites, and delivery beam energies. However, the delivery QA results for all QA systems based on the TPS calculation showed a good agreement of more than 90% for both the criteria. It is concluded that the three 2D QA systems have sufficient potential for pretreatment verification of the SBRT-VMAT plan. PMID:27709851

  3. Dosimetric properties characterization of silicon diodes used in photon beam radiotherapy; Caracterizacao das propriedades dosimetricas de diodos de silicio empregados em radioterapia com fotons

    Energy Technology Data Exchange (ETDEWEB)

    Bizetto, Cesar Augusto

    2013-07-01

    In the current work it was studied the performance of epitaxial (EPI) and float zone (FZ) silicon diodes as on-line dosimeters for megavoltage (EPI diode) and orthovoltage (EPI and FZ diode) photon beam radiotherapy. In order to be used as dosimeters the diodes were enclosed in black polymethylmethacrylate (PMMA) probes. The devices were then connected, on photovoltaic mode, to an electrometer KeithleyÒ 6517B to allow measurements of the photocurrent. The irradiations were performed with 6 and 18 MV photon beams (Siemens PrimusÒ linear accelerator), 6 and 15 MV (Novalis TXÒ) and 10, 25, 30 and 50 kV of a Pantak / Seifert X ray radiation device. During the measurements with the Siemens PrimusÒ the diodes were held between PMMA plates placed at 10.0 cm depth. When using Novalis TXÒ the devices were held between solid water plates placed at 50 cm depth. In both cases the diodes were centered in a radiation field of 10 x 10 cm{sup 2}, with the source-to-surface distance (SSD) kept at 100 cm. In measurements with orthovoltage photon beams the diodes were placed 50.0 cm from the tube in a radiation field of 8 cm diameter. The dose-rate dependency was studied for 6 and 15 MV (varying the dose-rate from 100 to 600 monitor units per minute) and for the 50 kV beam by varying the current tube from 2 to 20 mA. All devices showed linear response with dose rate and, within uncertainties the charge collected is independent of dose rate. The current signals induced showed good instantaneous repeatability of the diodes, characterized by coefficients of variation of current (CV) smaller than 1.14% (megavoltage beams) and 0.15% for orthovoltage beams and coefficients of variation of charge (CV) smaller than 1.84% (megavoltage beams) and 1.67% (orthovoltage beams). The dose response curves were quite linear with linear correlation coefficients better than 0.9999 for all diodes. (author)

  4. Dosimetric properties characterization of silicon diodes used in photon beam radiotherapy; Caracterizacao das propriedades dosimetricas de diodos de silicio empregados em radioterapia com feixe de fotons

    Energy Technology Data Exchange (ETDEWEB)

    Bizetto, Cesar Augusto

    2013-07-01

    In the current work it was studied the performance of epitaxial (EPI) and float zone (FZ) silicon diodes as on-line dosimeters for megavoltage (EPI diode) and orthovoltage (EPI and FZ diode) photon beam radiotherapy. In order to be used as dosimeters the diodes were enclosed in black polymethylmethacrylate (PMMA) probes. The devices were then connected, on photovoltaic mode, to an electrometer Keithley Registered-Sign 6517B to allow measurements of the photocurrent. The irradiations were performed with 6 and 18 MV photon beams (Siemens Primus Registered-Sign linear accelerator), 6 and 15 MV (Novalis TX Registered-Sign ) and 10, 25, 30 and 50 kV of a Pantak / Seifert X ray radiation device. During the measurements with the Siemens Primus the diodes were held between PMMA plates placed at 10.0 cm depth. When using Novalis TX Registered-Sign the devices were held between solid water plates placed at 50 cm depth. In both cases the diodes were centered in a radiation field of 10 x 10 cm{sup 2}, with the source-to-surface distance (SSD) kept at 100 cm. In measurements with orthovoltage photon beams the diodes were placed 50.0 cm from the tube in a radiation field of 8 cm diameter. The dose-rate dependency was studied for 6 and 15 MV (varying the dose-rate from 100 to 600 monitor units per minute) and for the 50 kV beam by varying the current tube from 2 to 20 mA. All devices showed linear response with dose rate and, within uncertainties the charge collected is independent of dose rate. The current signals induced showed good instantaneous repeatability of the diodes, characterized by coefficients of variation of current (CV) smaller than 1.14% (megavoltage beams) and 0.15% for orthovoltage beams and coefficients of variation of charge (CV) smaller than 1.84% (megavoltage beams) and 1.67% (orthovoltage beams). The dose response curves were quite linear with linear correlation coefficients better than 0.9999 for all diodes. (author)

  5. SU-E-T-409: Evaluation of Tissue Composition Effect On Dose Distribution in Radiotherapy with 6 MV Photon Beam of a Medical Linac

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, M; Tabatabaei, Z; Noghreiyan, A Vejdani [Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, NV (United States)

    2015-06-15

    Purpose: The aim of this study is to evaluate soft tissue composition effect on dose distribution for various soft tissues and various depths in radiotherapy with 6 MV photon beam of a medical linac. Methods: A phantom and Siemens Primus linear accelerator were simulated using MCNPX Monte Carlo code. In a homogeneous cubic phantom, six types of soft tissue and three types of tissue-equivalent materials were defined separately. The soft tissues were muscle (skeletal), adipose tissue, blood (whole), breast tissue, soft tissue (9-component) and soft tissue (4-component). The tissue-equivalent materials included: water, A-150 tissue-equivalent plastic and perspex. Photon dose relative to dose in 9-component soft tissue at various depths on the beam’s central axis was determined for the 6 MV photon beam. The relative dose was also calculated and compared for various MCNPX tallies including,F8, F6 and,F4. Results: The results of the relative photon dose in various materials relative to dose in 9-component soft tissue and using different tallies are reported in the form of tabulated data. Minor differences between dose distributions in various soft tissues and tissue-equivalent materials were observed. The results from F6 and F4 were practically the same but different with,F8 tally. Conclusion: Based on the calculations performed, the differences in dose distributions in various soft tissues and tissue-equivalent materials are minor but they could be corrected in radiotherapy calculations to upgrade the accuracy of the dosimetric calculations.

  6. The feasibility and safety of high-intensity focused ultrasound combined with low-dose external beam radiotherapy as supplemental therapy for advanced prostate cancer following hormonal therapy

    Institute of Scientific and Technical Information of China (English)

    Rui-Yi Wu; Guo-Min Wang; Lei Xu; Bo-Heng Zhang; Ye-Qing Xu; Zhao-Chong Zeng; Bing Chen

    2011-01-01

    The aim of this study was to investigate the feasibility and safety of high-intensity focused ultrasound (HIFU) combined with (+) low-dose external beam radiotherapy (LRT) as supplemental therapy for advanced prostate cancer (PCa) following hormonal therapy (HT). Our definition of HIFU+LRT refers to treating primary tumour lesions with HIFU in place of reduced field boost irradiation to the prostate, while retaining four-field box irradiation to the pelvis in conventional-dose external beam radiotherapy (CRT). We performed a prospective, controlled and non-randomized study on 120 patients with advanced PCa after HT who received HIFU, CRT, HIFU+LRT and HT alone, respectively. CT/MR imaging showed the primary tumours and pelvic lymph node metastases visibly shrank or even disappeared after HIFU+LRT treatment. There were significant differences among four groups with regard to overall survival (OS) and disease-specific survival (DSS) curves (P=0.018 and 0.015). Further comparison between each pair of groups suggested that the long-term DSS of the HIFU+LRT group was higher than those of the other three groups, but there was no significant difference between the HIFU+LRT group and the CRT group. Multivariable Cox's proportional hazard model showed that both HIFU+LRT and CRT were independently associated with DSS (P=0.001 and 0.035) and had protective effects with regard to the risk of death. Compared with CRT, HIFU+LRT significantly decreased incidences of radiation-related late gastrointestinal (GI) and genitourinary (GU) toxicity grade ≥II. In conclusion, long-term survival of patients with advanced PCa benefited from strengthening local control of primary tumour and regional lymph node metastases after HT. As an alternative to CRT, HIFU+LRT showed good efficacy and better safety.

  7. Concurrent Radiotherapy and Gemcitabine for Unresectable Pancreatic Adenocarcinoma: Impact of Adjuvant Chemotherapy on Survival

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Kazuhiko, E-mail: kogawa@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, Okinawa (Japan); Ito, Yoshinori [Department of Radiation Oncology, National Cancer Center, Tokyo (Japan); Hirokawa, Naoki [Department of Radiology, Sapporo Medical University, Sapporo (Japan); Shibuya, Keiko [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University, Kyoto (Japan); Kokubo, Masaki [Department of Radiation Oncology, Institute of Biomedical Research and Innovation Hospital, Kobe (Japan); Ogo, Etsuyo [Department of Radiation Oncology, Kurume University, Kurume (Japan); Shibuya, Hitoshi [Department of Radiology, Tokyo Medical and Dental University, Tokyo (Japan); Saito, Tsutomu [Department of Radiation Oncology, Nihon University Itabashi Hospital, Tokyo (Japan); Onishi, Hiroshi [Department of Radiology, Yamanashi University, Yamanashi (Japan); Karasawa, Katsuyuki [Department of Radiation Oncology, Tokyo Metropolitan Komagome Hospital, Tokyo (Japan); Nemoto, Kenji [Department of Radiation Oncology, Yamagata University, Yamagata (Japan); Nishimura, Yasumasa [Department of Radiation Oncology, Kinki University School of Medicine, Osaka (Japan)

    2012-06-01

    Purpose: To retrospectively analyze results of concurrent chemoradiotherapy (CCRT) using gemcitabine (GEM) for unresectable pancreatic adenocarcinoma. Methods and Materials: Records of 108 patients treated with concurrent external beam radiotherapy (EBRT) and GEM were reviewed. The median dose of EBRT in all 108 patients was 50.4 Gy (range, 3.6-60.8 Gy), usually administered in conventional fractionations (1.8-2 Gy/day). During radiotherapy, most patients received GEM at a dosage of 250 to 350 mg/m{sup 2} intravenously weekly for approximately 6 weeks. After CCRT, 59 patients (54.6%) were treated with adjuvant chemotherapy (AC), mainly with GEM. The median follow-up for all 108 patients was 11.0 months (range, 0.4-37.9 months). Results: Initial responses after CCRT for 85 patients were partial response: 26 patients, no change: 51 patients and progressive disease: 8 patients. Local progression was observed in 35 patients (32.4%), and the 2-year local control (LC) rate in all patients was 41.9%. Patients treated with total doses of 50 Gy or more had significantly more favorable LC rates (2-year LC rate, 42.9%) than patients treated with total doses of less than 50 Gy (2-year LC rate, 29.6%). Regional lymph node recurrence was found in only 1 patient, and none of the 57 patients with clinical N0 disease had regional lymph node recurrence. The 2-year overall survival (OS) rate and the median survival time in all patients were 23.5% and 11.6 months, respectively. Patients treated with AC had significantly more favorable OS rates (2-year OS, 31.8%) than those treated without AC (2-year OS, 12.4%; p < 0.0001). On multivariate analysis, AC use and clinical T stage were significant prognostic factors for OS. Conclusions: CCRT using GEM yields a relatively favorable LC rate for unresectable pancreatic adenocarcinoma, and CCRT with AC conferred a survival benefit compared to CCRT without AC.

  8. Integration of PET-CT and cone-beam CT for image-guided radiotherapy with high image quality and registration accuracy

    Science.gov (United States)

    Wu, T.-H.; Liang, C.-H.; Wu, J.-K.; Lien, C.-Y.; Yang, B.-H.; Huang, Y.-H.; Lee, J. J. S.

    2009-07-01

    Hybrid positron emission tomography-computed tomography (PET-CT) system enhances better differentiation of tissue uptake of 18F-fluorodeoxyglucose (18F-FDG) and provides much more diagnostic value in the non-small-cell lung cancer and nasopharyngeal carcinoma (NPC). In PET-CT, high quality CT images not only offer diagnostic value on anatomic delineation of the tissues but also shorten the acquisition time for attenuation correction (AC) compared with PET-alone imaging. The linear accelerators equipped with the X-ray cone-beam computed tomography (CBCT) imaging system for image-guided radiotherapy (IGRT) provides excellent verification on position setup error. The purposes of our study were to optimize the CT acquisition protocols of PET-CT and to integrate the PET-CT and CBCT for IGRT. The CT imaging parameters were modified in PET-CT for increasing the image quality in order to enhance the diagnostic value on tumour delineation. Reproducibility and registration accuracy via bone co-registration algorithm between the PET-CT and CBCT were evaluated by using a head phantom to simulate a head and neck treatment condition. Dose measurement in computed tomography dose index (CTDI) was also estimated. Optimization of the CT acquisition protocols of PET-CT was feasible in this study. Co-registration accuracy between CBCT and PET-CT on axial and helical modes was in the range of 1.06 to 2.08 and 0.99 to 2.05 mm, respectively. In our result, it revealed that the accuracy of the co-registration with CBCT on helical mode was more accurate than that on axial mode. Radiation doses in CTDI were 4.76 to 18.5 mGy and 4.83 to 18.79 mGy on axial and helical modes, respectively. Registration between PET-CT and CBCT is a state-of-the-art registration technology which could provide much information on diagnosis and accurate tumour contouring on radiotherapy while implementing radiotherapy procedures. This novelty technology of PET-CT and cone-beam CT integration for IGRT may have a

  9. Integration of PET-CT and cone-beam CT for image-guided radiotherapy with high image quality and registration accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, T-H [Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, No. 110, Sec.1, Jianguo N.Rd, Taichung City 40201, Taiwan (China); Liang, C-H [Agfa Healthcare Systems Taiwan Co., Ltd., 6F, 237 Sung Chiang Road, Taipei, 104 Taiwan (China); Wu, J-K [Division of Radiation Oncology, Department of Oncology, and Cancer Research Center, National Taiwan University Hospital, No.7 Chung San South Road, Taipei, 104 Taiwan (China); Lien, C-Y [Institute of Biomedical Engineering, National Yang Ming University, No. 155, Sec.2, Linong Street, Taipei, 112 Taiwan (China); Yang, B-H; Lee, J J S [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, No. 155, Sec.2, Linong Street, Taipei, 112 Taiwan (China); Huang, Y-H [Department of Medical Imaing and Radiological Sciences, I-Shou University, No. 8, Yida Rd., Yanchao Township, Kaohsiung County 82445, Taiwan (China)], E-mail: jslee@ym.edu.tw

    2009-07-15

    Hybrid positron emission tomography-computed tomography (PET-CT) system enhances better differentiation of tissue uptake of {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) and provides much more diagnostic value in the non-small-cell lung cancer and nasopharyngeal carcinoma (NPC). In PET-CT, high quality CT images not only offer diagnostic value on anatomic delineation of the tissues but also shorten the acquisition time for attenuation correction (AC) compared with PET-alone imaging. The linear accelerators equipped with the X-ray cone-beam computed tomography (CBCT) imaging system for image-guided radiotherapy (IGRT) provides excellent verification on position setup error. The purposes of our study were to optimize the CT acquisition protocols of PET-CT and to integrate the PET-CT and CBCT for IGRT. The CT imaging parameters were modified in PET-CT for increasing the image quality in order to enhance the diagnostic value on tumour delineation. Reproducibility and registration accuracy via bone co-registration algorithm between the PET-CT and CBCT were evaluated by using a head phantom to simulate a head and neck treatment condition. Dose measurement in computed tomography dose index (CTDI) was also estimated. Optimization of the CT acquisition protocols of PET-CT was feasible in this study. Co-registration accuracy between CBCT and PET-CT on axial and helical modes was in the range of 1.06 to 2.08 and 0.99 to 2.05 mm, respectively. In our result, it revealed that the accuracy of the co-registration with CBCT on helical mode was more accurate than that on axial mode. Radiation doses in CTDI were 4.76 to 18.5 mGy and 4.83 to 18.79 mGy on axial and helical modes, respectively. Registration between PET-CT and CBCT is a state-of-the-art registration technology which could provide much information on diagnosis and accurate tumour contouring on radiotherapy while implementing radiotherapy procedures. This novelty technology of PET-CT and cone-beam CT integration for IGRT

  10. Intercomparison of ionization chambers in standard X-ray beams, at radiotherapy, diagnostic radiology and radioprotection levels; Intercomparacao de camaras de ionizacao em feixes padroes de raios X, niveis radioterapia, radiodiagnostico e radioprotecao

    Energy Technology Data Exchange (ETDEWEB)

    Bessa, Ana Carolina Moreira de

    2006-07-01

    Since the calibration of radiation measurement instruments and the knowledge of their major characteristics are very important subjects, several different types of ionization chambers were intercompared in terms of their calibration coefficients and their energy dependence, in radiotherapy, diagnostic radiology and radioprotection standard beams. An intercomparison of radionuclide calibrators for nuclear medicine was performed, using three radionuclides: {sup 67}Ga, {sup 201}Tl and {sup 99m}Tc; the results obtained were all within the requirements of the national standard CNEN-NE-3.05. In order to complete the range of radiation qualities of the Calibration Laboratory of IPEN, standard radiation beam qualities, radiation protection and low energy radiation therapy levels, were established, according international recommendations. Three methodologies for the calibration of unsealed ionization chambers in X-ray beams were studied and compared. A set of Victoreen ionization chambers, specially designed for use in laboratorial intercomparisons, was submitted to characterization tests. The performance of these Victoreen ionization chambers showed that they are suitable for use in radioprotection beams, because the results obtained agree with international recommendations. However, these Victoreen ionization chambers can be used in radiotherapy and diagnostic radiology beams only with some considerations, since their performance in these beams, especially in relation to the energy dependence and stabilization time tests, did not agree with the international recommendations for dosimeters used in radiotherapy and diagnostic radiology beams. This work presents data on the performance of several types of ionization chambers in different X-ray beams, that may be useful for choosing the appropriate instrument for measurements in ionizing radiation beams. (author)

  11. Whole-pelvic radiotherapy with spot-scanning proton beams for uterine cervical cancer: a planning study

    Science.gov (United States)

    Hashimoto, Shingo; Shibamoto, Yuta; Iwata, Hiromitsu; Ogino, Hiroyuki; Shibata, Hiroki; Toshito, Toshiyuki; Sugie, Chikao; Mizoe, Jun-etsu

    2016-01-01

    The aim of this study was to compare the dosimetric parameters of whole-pelvic radiotherapy (WPRT) for cervical cancer among plans involving 3D conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), or spot-scanning proton therapy (SSPT). The dose distributions of 3D-CRT-, IMRT-, and SSPT-based WPRT plans were compared in 10 patients with cervical cancer. All of the patients were treated with a prescribed dose of 50.4 Gy in 1.8-Gy daily fractions, and all of the plans involved the same planning target volume (PTV) constrictions. A 3D-CRT plan involving a four-field box, an IMRT plan involving seven coplanar fields, and an SSPT plan involving four fields were created. The median PTV D95% did not differ between the 3D-CRT, IMRT and SSPT plans. The median conformity index 95% and homogeneity index of the IMRT and SSPT were better than those of the 3D-CRT. The homogeneity index of the SSPT was better than that of the IMRT. SSPT resulted in lower median V20 values for the bladder wall, small intestine, colon, bilateral femoral heads, skin, and pelvic bone than IMRT. Comparing the Dmean values, SSPT spared the small intestine, colon, bilateral femoral heads, skin and pelvic bone to a greater extent than the other modalities. SSPT can reduce the irradiated volume of the organs at risk compared with 3D-CRT and IMRT, while maintaining excellent PTV coverage. Further investigations of SSPT are warranted to assess its role in the treatment of cervical cancer. PMID:27380800

  12. Application of megavoltage cone-beam computed tomography in radiotherapy%兆伏锥形束CT在放疗中的应用

    Institute of Scientific and Technical Information of China (English)

    高云生; 胡伟刚; 胡超苏

    2008-01-01

    兆伏锥形束CT(MVCBCT)在体内有金属移植物时可以消除金属对散射线的影响,提高图像质量,便于勾画靶区,纠正摆位误差,并且可以监测治疗期间患者解剖结构的变化.通过放射治疗过程中的MVCBCT图像进行剂量监测和计算,可了解肿瘤退缩、患者体重减轻等对靶区和正常组织所受剂量的影响,更为重要的是可在其图像上进行图像引导放射治疗的研究.%Megavoltage cone-beam computed tomography can eliminate the impact of metal scattering to improve imaging quality, and help to contour targets and organs-at-risk, correct positioning errors and monitor the anatomical structure changes of patients in treatment room. During the course of treatment, megavohage cone-beam CT image can monitor the variation of dose distribution that results from tumor shrinkage, weight loss, etc. More importantly, the images can be applied to image-guided radiotherapy research.

  13. Real-time respiration monitoring using the radiotherapy treatment beam and four-dimensional computed tomography (4DCT)--a conceptual study.

    Science.gov (United States)

    Lu, Weiguo; Ruchala, Kenneth J; Chen, Ming-Li; Chen, Quan; Olivera, Gustavo H

    2006-09-21

    Real-time knowledge of intra-fraction motion, such as respiration, is essential for four-dimensional (4D) radiotherapy. Surrogate-based and internal-fiducial-based methods may suffer from one or many drawbacks such as false correlation, being invasive, delivering extra patient radiation, and requiring complicated hardware and software development and implementation. In this paper we develop a simple non-surrogate, non-invasive method to monitor respiratory motion during radiotherapy treatments in real time. This method directly utilizes the treatment beam and thus imposes no additional radiation to the patient. The method requires a pre-treatment 4DCT and a real-time detector system. The method combines off-line processes with on-line processes. The off-line processes include 4DCT imaging and pre-calculating detector signals at each phase of the 4DCT based on the planned fluence map and the detector response function. The on-line processes include measuring detector signal from the treatment beam, and correlating the measured detector signal with the pre-calculated signals. The respiration phase is determined as the position of peak correlation. We tested our method with extensive simulations based on a TomoTherapy machine and a 4DCT of a lung cancer patient. Three types of simulations were implemented to mimic the clinical situations. Each type of simulation used three different TomoTherapy delivery sinograms, each with 800 to 1000 projections, as input fluences. Three arbitrary breathing patterns were simulated and two dose levels, 2 Gy/fraction and 2 cGy/fraction, were used for simulations to study the robustness of this method against detector quantum noise. The algorithm was used to determine the breathing phases and this result was compared with the simulated breathing patterns. For the 2 Gy/fraction simulations, the respiration phases were accurately determined within one phase error in real time for most projections of the treatment, except for a few

  14. A case study comparing the relative benefit of optimizing beam weights, wedge angles, beam orientations and tomotherapy in stereotactic radiotherapy of the brain

    Science.gov (United States)

    Oldham, M.; Khoo, V. S.; Rowbottom, C. G.; Bedford, J. L.; Webb, S.

    1998-08-01

    A treatment-planning case study has been performed on a patient with a medium-sized, convex brain tumour. The study involved the application of advanced treatment-plan optimization techniques to improve on the dose distribution of the `standard plan' used to treat the patient. The standard plan was created according to conventional protocol at the Royal Marsden NHS Trust, and consisted of a three-field (one open and two wedged) non-coplanar arrangement, with field shaping to the beam's-eye view of the planning target volume (PTV). Three optimized treatment plans were created corresponding to (i) the optimization of the beam weights and wedge angles of the standard plan, (ii) the optimization of the beam orientations, beam weights and wedge angles of the standard plan, and (iii) a full fluence tomotherapy optimization of 1 cm wide (at isocentre), 43/8/010/img8.gif" ALIGN="MIDDLE"/> arcs. (i) and (ii) were created on the VOXELPLAN research 3D treatment-planning system, using in-house developed optimization algorithms, and (iii) was created on the PEACOCK tomotherapy planning system. The downhill-simplex optimization algorithm is used, in conjuction with `threshold-dose' cost-function terms enabling the algorithm to optimize specific regions of the dose-volume histogram (DVH) curve. The `beam-cost plot' tool is presented as a visual aid to the selection of beneficial beam directions. The methods and pitfalls in the transfer of plans and patient data between the two planning systems are discussed. Each optimization approach was evaluated, relative to the standard plan, on the basis of DVH and dose statistics in the PTV and organs at risk (OARs). All three optimization approaches were able to improve on the dose distribution of the standard plan. The magnitude of the improvement was greater for the optimized beam-orientation and tomotherapy plans (up to 15% and 30% for the maximum and mean OAR doses). A smaller improvement was observed in the beam-weight and wedge

  15. Accuracy of software-assisted contour propagation from planning CT to cone beam CT in head and neck radiotherapy

    DEFF Research Database (Denmark)

    Hvid, Christian A.; Elstrøm, Ulrik V.; Jensen, Kenneth

    2016-01-01

    . A cross sectional quality of life study of 116 recurrence free head and neck cancer patients. The first use of EORTC H&N35 in Danish. Acta Oncol 2006;45:28–37. Jensen K, Lambertsen K, Grau C. Late swallowing dysfunction and dysphagia after radiotherapy for pharynx cancer: frequency, intensity...... contouring of target volumes and normal tissues, which remains a time consuming task, even for experienced clinicians. There is a growing array of commercial software aimed at easing this burden by automatic contouring, utilizing novel deformable image registration (DIR) techniques to propagate one set...... have been found to reduce contouring time considerably [15 La Macchia M, Fellin F, Amichetti M, et al. Systematic evaluation of three different commercial software solutions for automatic segmentation for adaptive therapy in head-and-neck, prostate and pleural cancer. Radiat Oncol 2012;7:160. [Cross...

  16. Dosimetric effect of intrafraction motion and residual setup error for hypofractionated prostate intensity-modulated radiotherapy with online cone beam computed tomography image guidance.

    LENUS (Irish Health Repository)

    Adamson, Justus

    2012-02-01

    PURPOSE: To quantify the dosimetric effect and margins required to account for prostate intrafractional translation and residual setup error in a cone beam computed tomography (CBCT)-guided hypofractionated radiotherapy protocol. METHODS AND MATERIALS: Prostate position after online correction was measured during dose delivery using simultaneous kV fluoroscopy and posttreatment CBCT in 572 fractions to 30 patients. We reconstructed the dose distribution to the clinical tumor volume (CTV) using a convolution of the static dose with a probability density function (PDF) based on the kV fluoroscopy, and we calculated the minimum dose received by 99% of the CTV (D(99)). We compared reconstructed doses when the convolution was performed per beam, per patient, and when the PDF was created using posttreatment CBCT. We determined the minimum axis-specific margins to limit CTV D(99) reduction to 1%. RESULTS: For 3-mm margins, D(99) reduction was <\\/=5% for 29\\/30 patients. Using post-CBCT rather than localizations at treatment delivery exaggerated dosimetric effects by ~47%, while there was no such bias between the dose convolved with a beam-specific and patient-specific PDF. After eight fractions, final cumulative D(99) could be predicted with a root mean square error of <1%. For 90% of patients, the required margins were <\\/=2, 4, and 3 mm, with 70%, 40%, and 33% of patients requiring no right-left (RL), anteroposterior (AP), and superoinferior margins, respectively. CONCLUSIONS: For protocols with CBCT guidance, RL, AP, and SI margins of 2, 4, and 3 mm are sufficient to account for translational errors; however, the large variation in patient-specific margins suggests that adaptive management may be beneficial.

  17. Lack of benefit for the addition of androgen deprivation therapy to dose-escalated radiotherapy in the treatment of intermediate- and high-risk prostate cancer.

    LENUS (Irish Health Repository)

    Krauss, Daniel

    2012-02-01

    PURPOSE: Assessment of androgen deprivation therapy (ADT) benefits for prostate cancer treated with dose-escalated radiotherapy (RT). METHODS AND MATERIALS: From 1991 to 2004, 1,044 patients with intermediate- (n = 782) or high-risk (n = 262) prostate cancer were treated with dose-escalated RT at William Beaumont Hospital. Patients received external-beam RT (EBRT) alone, brachytherapy (high or low dose rate), or high dose rate brachytherapy plus pelvic EBRT. Intermediate-risk patients had Gleason score 7, prostate-specific antigen (PSA) 10.0-19.9 ng\\/mL, or Stage T2b-T2c. High-risk patients had Gleason score 8-10, PSA >\\/=20, or Stage T3. Patients were additionally divided specifically by Gleason score, presence of palpable disease, and PSA level to further define subgroups benefitting from ADT. RESULTS: Median follow-up was 5 years; 420 patients received ADT + dose-escalated RT, and 624 received dose-escalated RT alone. For all patients, no advantages in any clinical endpoints at 8 years were associated with ADT administration. No differences in any endpoints were associated with ADT administration based on intermediate- vs. high-risk group or RT modality when analyzed separately. Patients with palpable disease plus Gleason >\\/=8 demonstrated improved clinical failure rates and a trend toward improved survival with ADT. Intermediate-risk patients treated with brachytherapy alone had improved biochemical control when ADT was given. CONCLUSION: Benefits of ADT in the setting of dose-escalated RT remain poorly defined. This question must continue to be addressed in prospective study.

  18. Monte Carlo Simulation of Electron Beams for Radiotherapy - EGS4, MCNP4b and GEANT3 Intercomparison

    Science.gov (United States)

    Trindade, A.; Rodrigues, P.; Alves, C.; Chaves, A.; Lopes, M. C.; Oliveira, C.; Peralta, L.

    In medical radiation physics, an increasing number of Monte Carlo codes are being used, which requires intercomparison between them to evaluated the accuracy of the simulated results against benchmark experiments. The Monte Carlo code EGS4, commonly used to simulate electron beams from medical linear accelerators, was compared with GEANT3 and MCNP4b. Intercomparison of electron energy spectra, angular and spatial distribution were carried out for the Siemens KD2 linear accelerator, at beam energies of 10 and 15 MeV for a field size of 10x10 cm2. Indirect validation was performed against electron depth doses curves and beam profiles measured in a MP3-PTW water phantom using a Markus planar chamber. Monte Carlo isodose lines were reconstructed and compared to those from commercial treatment planning systems (TPS's) and with experimental data.

  19. Monte Carlo Simulation of Electron Beams for Radiotherapy - EGS4, MCNP4b and GEANT3 Intercomparison

    CERN Document Server

    Trindade, A; Alves, C M; Chaves, A; Lopes, C; Oliveira, C; Peralta, L

    2000-01-01

    In medical radiation physics, an increasing number of Monte Carlo codes are being used, which requires intercomparison between them to evaluated the accuracy of the simulated results against benchmark experiments. The Monte Carlo code EGS4, commonly used to simulate electron beams from medical linear accelerators, was compared with GEANT3 and MCNP4b. Intercomparison of electron energy spectra, angular and spatial distribution were carried out for the Siemens KD2 linear accelerator, at beam energies of 10 and 15 MeV for a field size of 10x10 cm2. Indirect validation was performed against electron depth doses curves and beam profiles measured in a MP3-PTW water phantom using a Markus planar chamber. Monte Carlo isodose lines were reconstructed and compared to those from commercial treatment planning systems (TPS's) and with experimental data.

  20. Effect of the normalized prescription isodose line on the magnitude of Monte Carlo vs. pencil beam target dose differences for lung stereotactic body radiotherapy.

    Science.gov (United States)

    Zheng, Dandan; Zhang, Qinghui; Liang, Xiaoying; Zhu, Xiaofeng; Verma, Vivek; Wang, Shuo; Zhou, Sumin

    2016-07-08

    In lung stereotactic body radiotherapy (SBRT) cases, the pencil beam (PB) dose calculation algorithm is known to overestimate target dose as compared to the more accurate Monte Carlo (MC) algorithm. We investigated whether changing the normalized prescription isodose line affected the magnitude of MC vs. PB target dose differences. Forty-eight patient plans and twenty virtual-tumor phantom plans were studied. For patient plans, four alternative plans prescribed to 60%, 70%, 80%, and 90% isodose lines were each created for 12 patients who previously received lung SBRT treatments. Using 6 MV dynamic conformal arcs, the plans were individually optimized to achieve similar dose coverage and conformity for all plans of the same patient, albeit at the different prescription levels. These plans, having used a PB algorithm, were all recalculated with MC to compare the target dose differences. The relative MC vs. PB target dose variations were investigated by comparing PTV D95, Dmean, and D5 loss at the four prescription levels. The MC-to-PB ratio of the plan heterogeneity index (HI) was also evaluated and compared among different isodose levels. To definitively demonstrate the cause of the isodose line dependence, a simulated phantom study was conducted using simple, spherical virtual tumors planned with uniform block margins. The tumor size and beam energy were also altered in the phantom study to investigate the interplay between these confounding factors and the isodose line effect. The magnitude of the target dose overestimation by PB was greater for higher prescription isodose levels. The MC vs. PB reduction in the target dose coverage indices, D95 and V100 of PTV, were found to monotonically increase with increasing isodose lines from 60% to 90%, resulting in more pronounced target dose coverage deficiency at higher isodose prescription levels. No isodose level-dependent trend was observed for the dose errors in the target mean or high dose indices, Dmean or D5. The

  1. Real-time optical-fibre luminescence dosimetry for radiotherapy: physical characteristics and applications in photon beams

    DEFF Research Database (Denmark)

    Aznar, M.C.; Andersen, C.E.; Bøtter-Jensen, L.;

    2004-01-01

    A new optical-fibre radiation dosimeter system, based on radioluminescence and optically stimulated luminescence from carbon-doped aluminium oxide, was developed and tested in clinical photon beams. This prototype offers several features, such as a small detector (1 x 1 x 2 mm), high sensitivity...

  2. WE-G-BRE-06: New Potential for Enhancing External Beam Radiotherapy for Lung Cancer Using FDA-Approved Concentrations of Cisplatin Or Carboplatin Nanoparticles Administered Via Inhalation

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Y; Altundal, Y; Sajo, E [University Massachusetts Lowell, Lowell, MA (United States); Detappe, A [Brigham ' Woman' s Hospital, Boston, MA (United States); Dana Farber Cancer Institute, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); University of Lyon, Lyon (France); Makrigiorgos, G; Berbeco, R [Brigham ' Woman' s Hospital, Boston, MA (United States); Dana Farber Cancer Institute, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Ngwa, W [University Massachusetts Lowell, Lowell, MA (United States); Brigham ' Woman' s Hospital, Boston, MA (United States); Dana Farber Cancer Institute, Boston, MA (United States); Harvard Medical School, Boston, MA (United States)

    2014-06-15

    Purpose: This study investigates, for the first time, the dose enhancement to lung tumors due to cisplatin nanoparticles (CNPs) and carboplatin nanoparticles (CBNPs) administered via inhalation route (IR) during external beam radiotherapy. Methods: Using Monte Carlo generated 6 MV energy fluence spectra, a previously employed analytic method was used to estimate dose enhancement to lung tumor due to radiation-induced photoelectrons from CNPs administered via IR in comparison to intravenous (IV) administration. Previous studies have indicated about 5% of FDA-approved cisplatin concentrations reach the lung tumor via IV. Meanwhile recent experimental studies indicate that 3.5–14.6 times higher concentrations of CNPs can reach the lung tumors by IR compared to IV. Taking these into account, the dose enhancement factor (DEF) defined as the ratio of the dose with and without CNPs was calculated for field size of 10 cm × 10 cm (sweeping gap), for a range of tumor depths and tumor sizes. Similar calculations were done for CBNPs. Results: For IR with 3.5 times higher concentrations than IV, and 2 cm diameter tumor, clinically significant DEF values of 1.19–1.30 were obtained for CNPs at 3–10 cm depth, respectively, in comparison to 1.06–1.09 for IV. For CBNPs, DEF values of 1.26–1.41 were obtained in comparison to 1.07–1.12 for IV. For IR with 14.6 times higher concentrations, higher DEF values were obtained e.g. 1.81–2.27 for CNPs. DEF increased with increasing field size or decreasing tumor size. Conclusions: Our preliminary results indicate that major dose enhancement to lung tumors can be achieved using CNPs/CBNPs administered via IR, in contrast to IV administration during external beam radiotherapy. These findings highlight a potential new approach for radiation boosting to lung tumors using CNPs/CBNPs administered via IR. This would, especially, be applicable during concomitant chemoradiotherapy, potentially allowing for dose enhancement while

  3. Study of the alignment of X radiation beam for calibration of chambers used in radiotherapy; Estudo do alinhamento do feixe de raios-X para calibracao de camaras utilizadas em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Ricardo de Souza; Bossio, Francisco; Peixoto, Jose Guilherme Pereira, E-mail: ricardo@ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    The activities developed in radiotherapy, diagnostic radiology and radiation safety, require that the metrological parameters involving these activities have on its results a high degree of reliability, to ensure traceability. To meet the existing demand in Brazil, the National Metrology Laboratory of Ionizing Radiation - LNMRI - is deploying a new tube X-ray beams used in the calibration of the standard rooms, which serve to quality control in hospitals, clinics and industry. (author)

  4. Evaluating uncertainties in the cross-calibration of parallel ion chambers used in electron beam radiotherapy; Avaliacao das incertezas no processo de calibracao cruzada de camaras de placas paralelas utilizadas em feixes de eletrons para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Ernani; Travassos, Paulo; Ferreira, Max da Silva; Carvalho, Samira Marques de; Silva, Michele Maria da; Peixoto, Jose Guilherme Pereira, E-mail: ernanianderson@hotmail.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Salmon Junior, Helio Augusto [Grupo COI - Clinicas Oncologicas, Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This study aims to estimative the combined standard uncertainty for a detector parallel plate used for dosimetry of electron beams in linear accelerators for radiotherapy, which has been calibrated by the cross-calibration method. Keeping the combined standard uncertainty next of the uncertainty informed in the calibration certificate of the reference chamber, become possible establish the calibration factor of the detector. The combined standard uncertainty obtained in this study was 2.5 %. (author)

  5. Prospective Multi-Institutional Study of Definitive Radiotherapy With High-Dose-Rate Intracavitary Brachytherapy in Patients With Nonbulky (<4-cm) Stage I and II Uterine Cervical Cancer (JAROG0401/JROSG04-2)

    Energy Technology Data Exchange (ETDEWEB)

    Toita, Takafumi, E-mail: b983255@med.u-ryukyu.ac.jp [Department of Radiology, Graduate School of Medical Science, University of Ryukyus, Okinawa (Japan); Kato, Shingo [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Niibe, Yuzuru [Department of Radiology, School of Medicine, Kitasato University, Sagamihara (Japan); Ohno, Tatsuya [Gunma University Heavy Ion Medical Center, Maebashi (Japan); Kazumoto, Tomoko [Department of Radiology, Saitama Cancer Center, Saitama (Japan); Kodaira, Takeshi [Department of Radiation Oncology, Aichi Cancer Center, Nagoya (Japan); Kataoka, Masaaki [Department of Radiology, National Shikoku Cancer Center, Ehime (Japan); Shikama, Naoto [Department of Radiation Oncology, Saku Central Hospital, Saku (Japan); Kenjo, Masahiro [Department of Radiation Oncology, Graduate School of Medical Science, Hiroshima University, Hiroshima (Japan); Tokumaru, Sunao [Department of Radiology, Saga University, Saga (Japan); Yamauchi, Chikako [Department of Radiation Oncology, Shiga Medical Center for Adults, Moriyama (Japan); Suzuki, Osamu [Department of Radiation Oncology, Osaka Medical Center for Cancer, Osaka (Japan); Sakurai, Hideyuki [Proton Medical Research Center and Tsukuba University, Tsukuba (Japan); Numasaki, Hodaka; Teshima, Teruki [Department of Medical Physics and Engineering, Graduate School of Medicine, Osaka University, Suita, Osaka (Japan); Oguchi, Masahiko [Department of Radiation Oncology, Cancer Institute Hospital, Tokyo (Japan); Kagami, Yoshikazu [Radiation Oncology Division, National Cancer Center Hospital, Tokyo (Japan); Nakano, Takashi [Department of Radiation Oncology, Gunma University, Graduate School of Medicine, Maebashi (Japan); Hiraoka, Masahiro [Department of Radiation Oncology and Image-applied Therapy, Kyoto University, Graduate School of Medicine, Kyoto (Japan); Mitsuhashi, Norio [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan)

    2012-01-01

    Purpose: To determine the efficacy of a definitive radiotherapy protocol using high-dose-rate intracavitary brachytherapy (HDR-ICBT) with a low cumulative dose schedule in nonbulky early-stage cervical cancer patients, we conducted a prospective multi-institutional study. Methods and Materials: Eligible patients had squamous cell carcinoma of the intact uterine cervix, Federation of Gynecologic Oncology and Obstetrics (FIGO) stages Ib1, IIa, and IIb, tumor size <40 mm in diameter (assessed by T2-weighted magnetic resonance imaging), and no pelvic/para-aortic lymphadenopathy. The treatment protocol consisted of whole-pelvis external beam radiotherapy (EBRT) of 20 Gy/10 fractions, pelvic EBRT with midline block of 30 Gy/15 fractions, and HDR-ICBT of 24 Gy/4 fractions (at point A). The cumulative biologically effective dose (BED) was 62 Gy{sub 10} ({alpha}/{beta} = 10) at point A. The primary endpoint was the 2-year pelvic disease progression-free (PDPF) rate. All patients received a radiotherapy quality assurance review. Results: Between September 2004 and July 2007, 60 eligible patients were enrolled. Thirty-six patients were assessed with FIGO stage Ib1; 12 patients with stage IIa; and 12 patients with stage IIb. Median tumor diameter was 28 mm (range, 6-39 mm). Median overall treatment time was 43 days. Median follow-up was 49 months (range, 7-72 months). Seven patients developed recurrences: 3 patients had pelvic recurrences (2 central, 1 nodal), and 4 patients had distant metastases. The 2-year PDPF was 96% (95% confidence interval [CI], 92%-100%). The 2-year disease-free and overall survival rates were 90% (95% CI, 82%-98%) and 95% (95% CI, 89%-100%), respectively. The 2-year late complication rates (according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer of Grade {>=}1) were 18% (95% CI, 8%-28%) for large intestine/rectum, 4% (95% CI, 0%-8%) for small intestine, and 0% for bladder. No Grade {>=}3 cases were

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-15

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

  7. High-density dental implants and radiotherapy planning: evaluation of effects on dose distribution using pencil beam convolution algorithm and Monte Carlo method.

    Science.gov (United States)

    Çatli, Serap

    2015-09-08

    High atomic number and density of dental implants leads to major problems at providing an accurate dose distribution in radiotherapy and contouring tumors and organs caused by the artifact in head and neck tumors. The limits and deficiencies of the algorithms using in the treatment planning systems can lead to large errors in dose calculation, and this may adversely affect the patient's treatment. In the present study, four commercial dental implants were used: pure titanium, titanium alloy (Ti-6Al-4V), amalgam, and crown. The effects of dental implants on dose distribution are determined with two methods: pencil beam convolution (PBC) algorithm and Monte Carlo code for 6 MV photon beam. The central axis depth doses were calculated on the phantom for a source-skin distance (SSD) of 100 cm and a 10 × 10 cm2 field using both of algorithms. The results of Monte Carlo method and Eclipse TPS were compared to each other and to those previously reported. In the present study, dose increases in tissue at a distance of 2 mm in front of the dental implants were seen due to the backscatter of electrons for dental implants at 6 MV using the Monte Carlo method. The Eclipse treatment planning system (TPS) couldn't precisely account for the backscatter radiation caused by the dental prostheses. TPS underestimated the back scatter dose and overestimated the dose after the dental implants. The large errors found for TPS in this study are due to the limits and deficiencies of the algorithms. The accuracy of the PBC algorithm of Eclipse TPS was evaluated in comparison to Monte Carlo calculations in consideration of the recommendations of the American Association of Physicists in Medicine Radiation Therapy Committee Task Group 65. From the comparisons of the TPS and Monte Carlo calculations, it is verified that the Monte Carlo simulation is a good approach to derive the dose distribution in heterogeneous media.

  8. SU-E-J-151: Dosimetric Evaluation of DIR Mapped Contours for Image Guided Adaptive Radiotherapy with 4D Cone-Beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Balik, S [Cleveland Clinic Foundation, Cleveland, OH (United States); Weiss, E; Williamson, J; Hugo, G [Virginia Commonwealth University, Richmond, VA (United States); Jan, N; Zhang, L [Virginia Commonwealth University, Richmond, Virginia (United States); Roman, N [San Antonio Precision Center Ctr, San Antonio, TX (United States); Christensen, G [University of Iowa, Iowa City, IA (United States)

    2014-06-01

    Purpose: To estimate dosimetric errors resulting from using contours deformably mapped from planning CT to 4D cone beam CT (CBCT) images for image-guided adaptive radiotherapy of locally advanced non-small cell lung cancer (NSCLC). Methods: Ten locally advanced non-small cell lung cancer (NSCLC) patients underwent one planning 4D fan-beam CT (4DFBCT) and weekly 4DCBCT scans. Multiple physicians delineated the gross tumor volume (GTV) and normal structures in planning CT images and only GTV in CBCT images. Manual contours were mapped from planning CT to CBCTs using small deformation, inverse consistent linear elastic (SICLE) algorithm for two scans in each patient. Two physicians reviewed and rated the DIR-mapped (auto) and manual GTV contours as clinically acceptable (CA), clinically acceptable after minor modification (CAMM) and unacceptable (CU). Mapped normal structures were visually inspected and corrected if necessary, and used to override tissue density for dose calculation. CTV (6mm expansion of GTV) and PTV (5mm expansion of CTV) were created. VMAT plans were generated using the DIR-mapped contours to deliver 66 Gy in 33 fractions with 95% and 100% coverage (V66) to PTV and CTV, respectively. Plan evaluation for V66 was based on manual PTV and CTV contours. Results: Mean PTV V66 was 84% (range 75% – 95%) and mean CTV V66 was 97% (range 93% – 100%) for CAMM scored plans (12 plans); and was 90% (range 80% – 95%) and 99% (range 95% – 100%) for CA scored plans (7 plans). The difference in V66 between CAMM and CA was significant for PTV (p = 0.03) and approached significance for CTV (p = 0.07). Conclusion: The quality of DIR-mapped contours directly impacted the plan quality for 4DCBCT-based adaptation. Larger safety margins may be needed when planning with auto contours for IGART with 4DCBCT images. Reseach was supported by NIH P01CA116602.

  9. High-density dental implants and radiotherapy planning: evaluation of effects on dose distribution using pencil beam convolution algorithm and Monte Carlo method.

    Science.gov (United States)

    Çatli, Serap

    2015-09-01

    High atomic number and density of dental implants leads to major problems at providing an accurate dose distribution in radiotherapy and contouring tumors and organs caused by the artifact in head and neck tumors. The limits and deficiencies of the algorithms using in the treatment planning systems can lead to large errors in dose calculation, and this may adversely affect the patient's treatment. In the present study, four commercial dental implants were used: pure titanium, titanium alloy (Ti-6Al-4V), amalgam, and crown. The effects of dental implants on dose distribution are determined with two methods: pencil beam convolution (PBC) algorithm and Monte Carlo code for 6 MV photon beam. The central axis depth doses were calculated on the phantom for a source-skin distance (SSD) of 100 cm and a 10×10 cm2 field using both of algorithms. The results of Monte Carlo method and Eclipse TPS were compared to each other and to those previously reported. In the present study, dose increases in tissue at a distance of 2 mm in front of the dental implants were seen due to the backscatter of electrons for dental implants at 6 MV using the Monte Carlo method. The Eclipse treatment planning system (TPS) couldn't precisely account for the backscatter radiation caused by the dental prostheses. TPS underestimated the back scatter dose and overestimated the dose after the dental implants. The large errors found for TPS in this study are due to the limits and deficiencies of the algorithms. The accuracy of the PBC algorithm of Eclipse TPS was evaluated in comparison to Monte Carlo calculations in consideration of the recommendations of the American Association of Physicists in Medicine Radiation Therapy Committee Task Group 65. From the comparisons of the TPS and Monte Carlo calculations, it is verified that the Monte Carlo simulation is a good approach to derive the dose distribution in heterogeneous media. PACS numbers: 87.55.K.

  10. Long-Term (10-Year Gastrointestinal and Genitourinary Toxicity after Treatment with External Beam Radiotherapy, Radical Prostatectomy, or Brachytherapy for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Grant K. Hunter

    2012-01-01

    Full Text Available Objective.To examine gastrointestinal (GI and genitourinary (GU toxicity profiles of patients treated in 1999 with external beam radiotherapy (RT, prostate interstitial brachytherapy (PI or radical prostatectomy (RP. Methods. TThe records of 525 patients treated in 1999 were reviewed to evaluate toxicity. Late GI and GU morbidities were graded according to the RTOG late morbidity criteria. Other factors examined were patient age, BMI, smoking history, and medical co-morbidities. Due to the low event rate for late GU and GI toxicities, a competing risk regression (CRR analysis was done with death as the competing event. Results. Median follow-up time was 8.5 years. On CRR univariate analysis, only the presence of DM was significantly associated with GU toxicity grade >2 (=0.43, HR 2.35, 95% Cl = 1.03–5.39. On univariate analysis, RT and DM were significantly associated with late GI toxicity. On multivariable analysis, both variables remained significant (RT: =0.038, HR=4.71, CI=1.09–20.3; DM: =0.008, HR=3.81, 95% Cl = 1.42–10.2. Conclusions. Late effects occur with all treatment modalities. The presence of DM at the time of treatment was significantly associated with worse late GI and GU toxicity. RT was significantly associated with worse late GI toxicity compared to PI and RP.

  11. Next generation multi-scale biophysical characterization of high precision cancer particle radiotherapy using clinical proton, helium-, carbon- and oxygen ion beams

    Science.gov (United States)

    Niklas, Martin; Zimmermann, Ferdinand; Chaudhri, Naved; Krunic, Damir; Tessonnier, Thomas; Ferrari, Alfredo; Parodi, Katia; Jäkel, Oliver; Debus, Jürgen; Haberer, Thomas; Abdollahi, Amir

    2016-01-01

    The growing number of particle therapy facilities worldwide landmarks a novel era of precision oncology. Implementation of robust biophysical readouts is urgently needed to assess the efficacy of different radiation qualities. This is the first report on biophysical evaluation of Monte Carlo simulated predictive models of prescribed dose for four particle qualities i.e., proton, helium-, carbon- or oxygen ions using raster-scanning technology and clinical therapy settings at HIT. A high level of agreement was found between the in silico simulations, the physical dosimetry and the clonogenic tumor cell survival. The cell fluorescence ion track hybrid detector (Cell-Fit-HD) technology was employed to detect particle traverse per cell nucleus. Across a panel of radiobiological surrogates studied such as late ROS accumulation and apoptosis (caspase 3/7 activation), the relative biological effectiveness (RBE) chiefly correlated with the radiation species-specific spatio-temporal pattern of DNA double strand break (DSB) formation and repair kinetic. The size and the number of residual nuclear γ-H2AX foci increased as a function of linear energy transfer (LET) and RBE, reminiscent of enhanced DNA-damage complexity and accumulation of non-repairable DSB. These data confirm the high relevance of complex DSB formation as a central determinant of cell fate and reliable biological surrogates for cell survival/RBE. The multi-scale simulation, physical and radiobiological characterization of novel clinical quality beams presented here constitutes a first step towards development of high precision biologically individualized radiotherapy. PMID:27494855

  12. Proton beam radiotherapy: report of the first patient treated at the Centro Nazionale di Adroterapia Oncologica (CNAO) [National Center of Oncologic Hadron Therapy].

    Science.gov (United States)

    Orecchia, Roberto; Srivastava, Anurita; Fiore, Maria Rosaria; Vitolo, Viviana; Fossati, Piero; Vischioni, Barbara; Iannalfi, Alberto; Tuan, Jeffrey; Ciocca, Mario; Molinelli, Silvia; Mirandola, Alfredo; Vilches, Gloria; Mairani, Andrea; Tagaste, Barbara; Baroni, Guido; Rossi, Sandro; Krengli, Marco

    2013-01-01

    Proton beam radiotherapy, an innovative treatment modality, allows delivery of high radiation doses to the target while sparing surrounding healthy structures. The Centro Nazionale di Adroterapia Oncologica (CNAO), equipped with a synchrotron and capable of using both protons and ions, initiated its clinical activity in September 2011. The first treatment of a skull base tumor with protons is reported here. The case of a 26-year-old man with an intracranial low-grade chondrosarcoma of the right petroclival junction is discussed with emphasis on technical and clinical details. Two previous surgical interventions had achieved partial removal of the tumor and the patient was treated with protons for residual disease. The prescribed dose was 70 GyE in 35 fractions of 2 GyE. Treatment was completed with minimal acute toxicity consisting of grade 1 alopecia and nausea. Nine months after treatment the disease is locally controlled. Use of high-energy protons at CNAO is a safe and effective means of treating a tumor located near critical normal structures.

  13. [Dosimetric comparing between protons beam and photons beam
for lung cancer radiotherapy: a meta-analysis].

    Science.gov (United States)

    Tian, Guangwei; Li, Nan; Li, Guang

    2013-05-01

    背景与目的 由于缺乏质子治疗与传统光子治疗比较的临床随机对照研究,导致质子治疗在肺癌放疗中的应用没有充足的临床证据。本研究旨在探讨质子射线在肺癌放疗中的剂量学优势,以期为临床提供有价值的循证医学依据。方法 计算机检索Cochrane Library、PubMed、EMbase、中国生物医学文献数据库、中国学术期刊全文数据库和中国科技期刊数据库,同时辅助其它检索,搜集所有比较质子射线与光子射线治疗肺癌的剂量学研究的文章,应用RevMan 5.2软件对满足条件的数据进行meta分析。结果 6篇文献纳入本次研究。质子射线与光子射线三维适形放疗(three-dimensional conformal radiotherapy, 3D-CRT)技术比较,降低了双肺Dmean(MD=-4.15, 95%CI: -5.56--2.74, P<0.001)及V20、V10、V5(MD=-10.92, 95%CI: -13.23--8.62, P<0.001);降低了食管Dmean及心脏Dmean,差异有统计学意义。质子射线与光子射线调强放疗(intensity-modulated radiotherapy, IMRT)技术比较,V20、V10、V5在质子射线治疗组明显降低(MD=-3.70, 95%CI: -5.31--2.10, P<0.001; MD=-8.86, 95%CI: -10.74--6.98, P<0.001; MD=-20.13, 95%CI: -27.11--13.14, P<0.001);而相比于光子射线(IMRT),质子射线治疗肺癌在食管Dmean差异无统计学意义,但心脏Dmean明显降低,差异有统计学意义。 结论 与目前普遍采用的光子射线(3D-CRT技术及IMRT技术)放疗相比,质子射线在治疗肺癌的剂量学方面有明显的优势,具有临床应用价值。

  14. Dosimetric comparison of flattened and unflattened beams for stereotactic ablative radiotherapy of stage I non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hrbacek, Jan, E-mail: jan.hrbacek@psi.ch [Klinik für Radio-Onkologie, UniversitätsSpital Zürich, 8091 Zürich, Switzerland and Center for Proton Therapy, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Lang, Stephanie; Graydon, Shaun N.; Klöck, Stephan; Riesterer, Oliver [Klinik für Radio-Onkologie, UniversitätsSpital Zürich, 8091 Zürich (Switzerland)

    2014-03-15

    Purpose: To compare contribution and accuracy of delivery for two flattening filter free (FFF) beams of the nominal energy 6 and 10 MV and a 6 MV flattened beam for early stage lung cancer. Methods: For each of 11 patients with stage I nonsmall cell lung cancer three volumetric modulated arc therapy plans were prepared utilizing a 6 MV flattened photon beam (X6FF) and two nonflattened beams of nominal energy 6 and 10 MV (X6FFF, X10FFF). Optimization constraints were set to produce dose distributions that meet the criteria of the RTOG-0915 protocol. The radiation schedule used for plan comparison in all patients was 50 Gy in five fractions. Dosimetric parameters of planning target volume (PTV) and organs-at-risk and delivery times were assessed and compared. All plans were subject to verification using Delta{sup 4} unit (Scandidos, Sweden) and absolutely calibrated gafchromic films in a thorax phantom. Results: All plans had a qualitatively comparable outcome. Obtained dose distributions were conformal (CI < 1.17) and exhibited a steep dose fall-off outside the PTV. The ratio of monitor units for FFF versus FF plans in the authors' study ranged from 0.95 to 1.21 and from 0.93 to 1.25 for X6FFF/X6FF and X10FFF/X6FF comparisons, respectively. The ratio systematically increased with increasing size of the PTV (up to +25% for 150 cm{sup 3} PTV). Yet the integral dose to healthy tissue did not follow this trend. Comparison of cumulative dose volume histograms for a patient's body showed that X6FFF plans exhibit improved conformity and reduced the volume of tissue that received more than 50% of the prescription dose. Parameters related to dose gradient showed statistically significant improvement. CI{sub 50%}, CI{sub 60%}, CI{sub 80%}, and CI{sub 100%} were on average reduced by 4.6% (p < 0.001), 4.6% (p = 0.002), 3.1% (p = 0.002), and 1.2% (p = 0.039), respectively. Gradient measure was on average reduced by 4.2% (p < 0.001). Due to dose reduction in the

  15. The field size matters: low dose external beam radiotherapy for thumb carpometacarpal osteoarthritis : Importance of field size.

    Science.gov (United States)

    Kaltenborn, Alexander; Bulling, Elke; Nitsche, Mirko; Carl, Ulrich Martin; Hermann, Robert Michael

    2016-08-01

    The purpose of this work was to evaluate the efficacy of low-dose radiotherapy (RT) for thumb carpometacarpal osteoarthritis (rhizarthrosis). The responses of 84 patients (n = 101 joints) were analyzed 3 months after therapy (n = 65) and at 12 months (n = 27). Patients were treated with 6 fractions of 1 Gy, two times a week, with a linear accelerator. At the end of therapy, about 70 % of patients reported a response (partial remission or complete remission), 3 months later about 60 %, and 1 year after treatment 70 %. In univariate regression analysis, higher patient age and field size greater than 6 × 4 cm were associated with response to treatment, while initial increase of pain under treatment was predictive for treatment failure. Duration of RT series (more than 18 days), gender, time of symptoms before RT, stress pain or rest pain, or prior ortheses use, injections, or surgery of the joint were not associated with treatment efficacy. In multivariate regression analysis, only field size and initial pain increase were highly correlated with treatment outcome. In conclusion, RT represents a useful treatment option for patients suffering from carpometacarpal osteoarthritis. In contrast to other benign indications, a larger field size (>6 × 4 cm) seems to be more effective than smaller fields and should be evaluated in further prospective studies.

  16. Detector to detector corrections: A comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Azangwe, Godfrey, E-mail: g.azangwe@iaea.org; Grochowska, Paulina; Izewska, Joanna; Meghzifene, Ahmed [International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna (Austria); Georg, Dietmar; Hopfgartner, Johannes; Lechner, Wolfgang [Department of Radiation Oncology, Medical University Vienna/AKH Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria and Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University Vienna, Vienna, Währinger Gürtel 18-20, A-1090 Vienna (Austria); Andersen, Claus E.; Beierholm, Anders R.; Helt-Hansen, Jakob [Center for Nuclear Technologies, Technical University of Denmark, Risø Campus, DK-4000 Roskilde (Denmark); Mizuno, Hideyuki; Fukumura, Akifumi [National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan); Yajima, Kaori [Association for Nuclear Technology in Medicine, 7-16, Nihonbashikodenmacho, chuou-ku, Tokyo 103-0001 (Japan); Gouldstone, Clare; Sharpe, Peter [National Physical Laboratory, Acoustics and Ionising Radiation Division, Teddington TW11 0LW (United Kingdom); Palmans, Hugo [National Physical Laboratory, Acoustics and Ionising Radiation Division, Teddington TW11 0LW, United Kingdom and EBG MedAustron GmbH, Medical Physics Department, A-2700 Wiener Neustadt (Austria)

    2014-07-15

    Purpose: The aim of the present study is to provide a comprehensive set of detector specific correction factors for beam output measurements for small beams, for a wide range of real time and passive detectors. The detector specific correction factors determined in this study may be potentially useful as a reference data set for small beam dosimetry measurements. Methods: Dose response of passive and real time detectors was investigated for small field sizes shaped with a micromultileaf collimator ranging from 0.6 × 0.6 cm{sup 2} to 4.2 × 4.2 cm{sup 2} and the measurements were extended to larger fields of up to 10 × 10 cm{sup 2}. Measurements were performed at 5 cm depth, in a 6 MV photon beam. Detectors used included alanine, thermoluminescent dosimeters (TLDs), stereotactic diode, electron diode, photon diode, radiophotoluminescent dosimeters (RPLDs), radioluminescence detector based on carbon-doped aluminium oxide (Al{sub 2}O{sub 3}:C), organic plastic scintillators, diamond detectors, liquid filled ion chamber, and a range of small volume air filled ionization chambers (volumes ranging from 0.002 cm{sup 3} to 0.3 cm{sup 3}). All detector measurements were corrected for volume averaging effect and compared with dose ratios determined from alanine to derive a detector correction factors that account for beam perturbation related to nonwater equivalence of the detector materials. Results: For the detectors used in this study, volume averaging corrections ranged from unity for the smallest detectors such as the diodes, 1.148 for the 0.14 cm{sup 3} air filled ionization chamber and were as high as 1.924 for the 0.3 cm{sup 3} ionization chamber. After applying volume averaging corrections, the detector readings were consistent among themselves and with alanine measurements for several small detectors but they differed for larger detectors, in particular for some small ionization chambers with volumes larger than 0.1 cm{sup 3}. Conclusions: The results demonstrate

  17. Locally advanced prostate cancer: combination of high-dose high-precision radiotherapy and androgen deprivation therapy%Locally advanced prostate cancer:combination of high-dose high-precision radiotherapy and androgen deprivation therapy

    Institute of Scientific and Technical Information of China (English)

    Michel Bolla; René-Olivier Mirimanoff

    2014-01-01

    Locally advanced prostate cancer entails a risk of local,regional and systemic relapse requiring the combination of a Ioco-regional treatment,namely external beam radiotherapy(EBRT) to control the pelvic-confined disease,combined with a systemic therapy,namely androgen-deprivation therapy(ADT),to potentiate irradiation and to destroy the infra-clinical androgen-dependant disease outside the irradiated volume.Many phases Ⅲ randomized trials have paved the way in establishing the indications of this combined approach,which requires a long term ADT(≥2 years) with LHRH agonists.The duration of ADT may be reduced to 6 months should there be a significant comorbidity,a reluctance from the patient or a poor tolerance.A multidisciplinary approach will enable physicians to tailor the treatment strategy and a close cooperation between the specialists and the general practitioners will be set up to prevent as much as possible the side-effects of ADT.

  18. Analysis of material characteristics for the construction of energy degrading and scattering plates for electron beam skin radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P.; Yoriyaz, Helio; Siqueira, Paulo T.D.; Antunes, Paula C.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)], e-mail: gabriel.fonseca@usp.br, e-mail: hyoriyas@ipen.br, e-mail: ptsiquei@ipen.br, e-mail: pacrisguian@usp.br; Furnari, Laura; Santos, Gabriela R. [Hospital das Clinicas de Sao Paulo, Sao Paulo, SP (Brazil). Inst. de Radiologia. Servico de Radioterapia], e-mail: laurafurnari@hotmail.com, e-mail: reis.gabby@gmail.com

    2009-07-01

    There are many radiosensitive diseases associated to the skin such as mycosis fungoids and the syndrome of Sezary that are part of a sub-group of cutaneous diseases type T-cell lymphoma. Several studies indicate the eradication of the disease when treated with linear accelerators emitting electron beams with energies between 4 to 10 MeV. However, this treatment technique presents innumerable technical challenges since the disease in general reaches all patient's body, becoming necessary a very large field size radiation beam, and also, it should deliver superficial doses limited to the skin depth. To reach the uniformity in the dose distribution, many techniques had already been developed. Based on these previous studies and guided by the report nr. 23 of the AAPM (American Association of Physicists in Medicine), the present study will develop an energy scattering and degrading plates, supplying subsidies for a future installation for skin treatment at the - Servico de Radioterapia do Hospital das Clinicas de Sao Paulo. As part of the plates design, first of all, the energy spectrum of the 6 MeV electron beam of the VARIAN 2100C accelerator was reconstructed through Monte Carlo simulations using the MCNP4C code and based on experimental data. Once the spectrum is built the design of the plates has been performed analyzing several materials, shapes and dimensions most adequate on the basis of radial and axial dose distribution, production of rays-x and dose attenuation. The simulations will be validated with experimental measurements using copper and aluminum. (author)

  19. Range degradation and distal edge behavior of proton radiotherapy beams using 11C activation and Monte Carlo simulation

    Science.gov (United States)

    Elmekawy, Ahmed Farouk

    The distal edge of therapeutic proton radiation beams was investigated by different methods. Proton beams produced at the Hampton University Proton Therapy Institute (HUPTI) were used to irradiate a Polymethylmethacrylate (PMMA) phantom for three different ranges (13.5, 17.0 and 21.0 cm) to investigate the distal slope dependence of the Bragg peak. The activation of 11 C was studied by scanning the phantom less than 10 minutes post-irradiation with a Philips Big Bore Gemini(c) PET/CT. The DICOM images were imported into the Varian Eclipse(c) Treatment Planning System (TPS) for analysis and then analyzed by ImageJ(c) . The distal slope ranged from ?0.1671 +/- 0.0036 to -0.1986 +/- 0.0052 (pixel intensity/slice number) for ranges 13.5 to 21.0 cm respectively. A realistic description of the setup was modeled using the GATE 7.0 Monte Carlo simulation tool and compared to the experiment data. The results show the distal slope ranged from -0.1158+/-0.0133 to -0.0787+/-0.002 (Gy/mm). Additionally, low activity, 11C were simulated to study the 11C reconstructed half-life dependence versus the initial activity for six ranges chosen around the previous activation study. The results of the expected/nominal half-life vs. activity ranged from -5 x 10-4 +/- 2.8104 x 10-4 to 1.6 x 10-3 +/- 9.44 x 10-4 (%diff./Bq). The comparison between two experiments with proton beams on a PMMA phantom and multi-layer ion chamber, and two GATE simulations of a proton beam incident on a water phantom and 11C PET study show that: (i) the distal fall-off variation of the steepness of the slopes are found to be similar thus validating the sensitivity of the PET technique to the range degradation and (ii) the average of the super-ratios difference between all studies observed is primarily due to the difference in the dose deposited in the media.

  20. Expanded risk groups help determine which prostate radiotherapy sub-group may benefit from adjuvant androgen deprivation therapy

    Directory of Open Access Journals (Sweden)

    Williams Scott G

    2008-04-01

    Full Text Available Abstract Purpose To assess whether an expanded (five level risk stratification system can be used to identify the sub-group of intermediate risk patients with prostate cancer who benefit from combining androgen deprivation therapy (ADT with external beam radiotherapy (EBRT. Materials and methods Using a previously validated 5-risk group schema, a prospective non-randomized data set of 1423 men treated at the British Columbia Cancer Agency was assessed for the primary end point of biochemical control (bNED with the RTOG-ASTRO "Phoenix" definition (lowest PSA to date + 2 ng/mL, both with and without adjuvant ADT. The median follow-up was 5 years. Results There was no bNED benefit for ADT in the low or low intermediate groups but there was a statistically significant bNED benefit in the high intermediate, high and extreme risk groups. The 5-year bNED rates with and without ADT were 70% and 73% respectively for the low intermediate group (p = non-significant and 72% and 58% respectively for the high intermediate group (p = 0.002. Conclusion There appears to be no advantage to ADT where the Gleason score is 6 or less and PSA is 15 or less. ADT is beneficial in patients treated to standard dose radiation with Gleason 6 disease and a PSA greater than 15 or where the Gleason score is 7 or higher.

  1. Randomized Control Trial: Evaluating Aluminum-Based Antiperspirant Use, Axilla Skin Toxicity, and Reported Quality of Life in Women Receiving External Beam Radiotherapy for Treatment of Stage 0, I, and II Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Linda C., E-mail: Linda.watson@albertahealthservices.ca [Department of Interdisciplinary Practice, Community Oncology, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Gies, Donna [Department of Radiation Oncology Nursing, Tom Baker Cancer Centre, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Thompson, Emmanuel [Department of Mathematics and Statistics, University of Calgary Faculty of Science, Calgary, AB (Canada); Thomas, Bejoy [Department of Psychosocial Resources, Tom Baker Cancer Centre, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Department of Psychosocial Oncology, University of Calgary Faculty of Medicine, Calgary, AB (Canada)

    2012-05-01

    Purpose: Standard skin care instructions regarding the use of antiperspirants during radiotherapy to the breast varies across North America. Women have articulated that when instructed to not use antiperspirant, the potential for body odor is distressing. Historical practices and individual opinions have often guided practice in this field. The present study had 2 purposes. To evaluate whether the use of aluminum-based antiperspirant while receiving external beam radiotherapy for stage 0, I, or II breast cancer will increase axilla skin toxicity and to evaluate whether the use of antiperspirant during external beam radiotherapy improves quality of life. Methods: A total of 198 participants were randomized to either the experimental group (antiperspirant) or control group (standard care-wash only). The skin reactions in both groups were measured weekly and 2 weeks after treatment using the National Cancer Institute Common Toxicity Criteria Adverse Events, version 3, toxicity grading criteria. Both groups completed the Functional Assessment for Chronic Illness Therapy's questionnaire for the breast population quality of life assessment tool, with additional questions evaluating the effect of underarm antiperspirant use on quality of life before treatment, immediately after treatment, and 2 weeks after treatment during the study. Results: The skin reaction data were analyzed using the generalized estimating equation. No statistically significant difference was seen in the skin reaction between the 2 groups over time. The quality of life data also revealed no statistically significant difference between the 2 groups over time. Conclusions: Data analysis indicates that using antiperspirant routinely during external beam radiotherapy for Stage 0, I, or II breast cancer does not affect the intensity of the skin reaction or the self-reported quality of life. This evidence supports that in this particular population, there is no purpose to restrict these women from

  2. Simulation of an antiprotons beam applied to the radiotherapy; Simulacao de um feixe de antiprotons aplicado a radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Prata, Leonardo de Almeida

    2006-07-15

    Results for the interaction of a antiproton beam with constituent nuclei of the organic matter are presented. This method regards of the application of an computational algorithm to determine quantitatively the differential cross sections for the scattered particles, starting from the interaction of these antiprotons with the nuclei, what will allow in the future to draw the isodose curve for antiproton therapy, once these beams are expected to be used in cancer treatment soon. The calculation will be done through the application of the concepts of the method of intranuclear cascade, providing yield and differential cross sections of the scattered particles, present in the software MCMC. Th algorithm was developed based on Monte Carlo's method, already taking into account a validate code. The following physical quantities are presented: the yield of secondary particles, their spectral and angular distributions for these interactions. For the energy range taken into account the more important emitted particles are protons, neutrons and pions. Results shown that emitted secondary particles can modify the isodose curves, because they present high yield and energy for transverse directions. (author)

  3. Fast kilovoltage/megavoltage (kVMV) breathhold cone-beam CT for image-guided radiotherapy of lung cancer

    Science.gov (United States)

    Wertz, Hansjoerg; Stsepankou, Dzmitry; Blessing, Manuel; Rossi, Michael; Knox, Chris; Brown, Kevin; Gros, Uwe; Boda-Heggemann, Judit; Walter, Cornelia; Hesser, Juergen; Lohr, Frank; Wenz, Frederik

    2010-08-01

    Long image acquisition times of 60-120 s for cone-beam CT (CBCT) limit the number of patients with lung cancer who can undergo volume image guidance under breathhold. We developed a low-dose dual-energy kilovoltage-megavoltage-cone-beam CT (kVMV-CBCT) based on a clinical treatment unit reducing imaging time to dose. Single MV-projections, reconstructed MV-CBCT images and images of simultaneous 90° kV- and 90° MV-CBCT (180° kVMV-CBCT) were acquired with different parameters. Image quality and imaging dose were evaluated and compared to kV-imaging. Hardware-based kVMV synchronization resulted in artifact-free projections. A combined 180° kVMV-CBCT scan with a total MV-dose of 5 monitor units was acquired in 15 s and with sufficient image quality. The resolution was 5-6 line pairs cm-1 (Catphan phantom). The combined kVMV-scan dose was equivalent to a kV-radiation scan dose of ~33 mGy. kVMV-CBCT based on a standard linac is promising and can provide ultra-fast online volume image guidance with low imaging dose and sufficient image quality for fast and accurate patient positioning for patients with lung cancer under breathhold.

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

    Science.gov (United States)

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

    2016-04-01

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

  5. Evaluation of the usefulness of the electron Monte Carlo algorithm for planning radiotherapy with the use of electron beams

    Science.gov (United States)

    Łukomska, Sandra; Kukołowicz, Paweł; Zawadzka, Anna; Gruda, Mariusz; Giżyńska, Marta; Jankowska, Anna; Piziorska, Maria

    2016-09-01

    The aim of the study was to verify the accuracy of calculations of dose distributions for electron beams performed using the electron Monte Carlo (eMC) v.10.0.28 algorithm implemented in the Eclipse treatment planning system (Varian Medical Systems). Implementation of the objective of the study was carried out in two stages. In the first stage the influence of several parameters defined by the user on the calculation accuracy was assessed. After selecting a set of parameters for which the best results were obtained a series of tests were carried. The tests were carried out in accordance with the recommendations of the Polish Society of Medical Physics (PSMP). The calculation and measurement of dose rate under reference conditions for semi quadratic and shaped fields were compared by individual cut-outs. We compared the calculated and measured percent depth doses, profiles and output factors for beams with an energy of 6, 9, 12, 15 and 18 MeV, for semi quadratic fields and for three different SSDs 100, 110, and 120 cm. All tests were carried out for beams generated in the Varian 2300CD Clinac linear accelerator. The results obtained during the first stage of the study demonstrated that the highest compliance between the calculations and measurements were obtained for the mean statistical uncertainty equal to 1, and the parameter responsible for smoothing the statistical noise defined as medium. Comparisons were made showing similar compliance calculations and measurements for the calculation grid of 0.1 cm and 0.25 cm and therefore the remaining part of the study was carried out for these two grids. In stage 2 it was demonstrated that the use of calculation grid of 0.1 cm allows for greater compliance of calculations and measurements. For energy 12, 15 and 18 MeV discrepancies between calculations and measurements, in most cases, did not exceed the PSMP action levels. The biggest differences between measurements and calculations were obtained for 6 MeV energy, for

  6. Experimental determination of field factors ([Formula: see text]) for small radiotherapy beams using the daisy chain correction method.

    Science.gov (United States)

    Lárraga-Gutiérrez, José Manuel

    2015-08-07

    Recently, Alfonso et al proposed a new formalism for the dosimetry of small and non-standard fields. The proposed new formalism is strongly based on the calculation of detector-specific beam correction factors by Monte Carlo simulation methods, which accounts for the difference in the response of the detector between the small and the machine specific reference field. The correct calculation of the detector-specific beam correction factors demands an accurate knowledge of the linear accelerator, detector geometry and composition materials. The present work shows that the field factors in water may be determined experimentally using the daisy chain correction method down to a field size of 1 cm × 1 cm for a specific set of detectors. The detectors studied were: three mini-ionization chambers (PTW-31014, PTW-31006, IBA-CC01), three silicon-based diodes (PTW-60018, IBA-SFD and IBA-PFD) and one synthetic diamond detector (PTW-60019). Monte Carlo simulations and experimental measurements were performed for a 6 MV photon beam at 10 cm depth in water with a source-to-axis distance of 100 cm. The results show that the differences between the experimental and Monte Carlo calculated field factors are less than 0.5%-with the exception of the IBA-PFD-for field sizes between 1.5 cm × 1.5 cm and 5 cm × 5 cm. For the 1 cm × 1 cm field size, the differences are within 2%. By using the daisy chain correction method, it is possible to determine measured field factors in water. The results suggest that the daisy chain correction method is not suitable for measurements performed with the IBA-PFD detector. The latter is due to the presence of tungsten powder in the detector encapsulation material. The use of Monte Carlo calculated [Formula: see text] is encouraged for field sizes less than or equal to 1 cm × 1 cm for the dosimeters used in this work.

  7. Detector to detector corrections: a comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams

    DEFF Research Database (Denmark)

    Azangwe, Godfrey; Grochowska, Paulina; Georg, Dietmar

    2014-01-01

    -doped aluminium oxide (Al2O3:C), organic plastic scintillators, diamond detectors, liquid filled ion chamber, and a range of small volume air filled ionization chambers (volumes ranging from 0.002 cm3 to 0.3 cm3). All detector measurements were corrected for volume averaging effect and compared with dose ratios.......148 for the 0.14 cm3 air filled ionization chamber and were as high as 1.924 for the 0.3 cm3 ionization chamber. After applying volume averaging corrections, the detector readings were consistent among themselves and with alanine measurements for several small detectors but they differed for larger detectors......, in particular for some small ionization chambers with volumes larger than 0.1 cm3. Conclusions: The results demonstrate how important it is for the appropriate corrections to be applied to give consistent and accurate measurements for a range of detectors in small beam geometry. The results further demonstrate...

  8. First dose-map measured with a polycrystalline diamond 2D dosimeter under an intensity modulated radiotherapy beam

    Energy Technology Data Exchange (ETDEWEB)

    Scaringella, M., E-mail: scaringella@gmail.com [Università di Firenze, Dipartimento di Ingegneria dell’Informazione, Firenze (Italy); Zani, M. [INFN Sezione di Firenze, Sesto Fiorentino, Firenze (Italy); Università di Firenze, Dipartimento di Scienze Biomediche, Sperimentali e Cliniche, Firenze (Italy); Baldi, A. [Università di Firenze, Dipartimento di Ingegneria Industriale, Firenze (Italy); Bucciolini, M. [INFN Sezione di Firenze, Sesto Fiorentino, Firenze (Italy); Università di Firenze, Dipartimento di Scienze Biomediche, Sperimentali e Cliniche, Firenze (Italy); Pace, E.; Sio, A. de [INFN Sezione di Firenze, Sesto Fiorentino, Firenze (Italy); Università di Firenze, Dipartimento di Fisica e Astronomia, Sesto Fiorentino, Firenze (Italy); Talamonti, C. [INFN Sezione di Firenze, Sesto Fiorentino, Firenze (Italy); Università di Firenze, Dipartimento di Scienze Biomediche, Sperimentali e Cliniche, Firenze (Italy); Bruzzi, M. [INFN Sezione di Firenze, Sesto Fiorentino, Firenze (Italy); Università di Firenze, Dipartimento di Fisica e Astronomia, Sesto Fiorentino, Firenze (Italy)

    2015-10-01

    A prototype of bidimensional dosimeter made on a 2.5×2.5 cm{sup 2} active area polycrystalline Chemical Vapour Deposited (pCVD) diamond film, equipped with a matrix of 12×12 contacts connected to the read-out electronics, has been used to evaluate a map of dose under Intensity Modulated Radiation Therapy (IMRT) fields for a possible application in pre-treatment verifications of cancer treatments. Tests have been performed under a 6–10 MVRX beams with IMRT fields for prostate and breast cancer. Measurements have been taken by measuring the 144 pixels in different positions, obtained by shifting the device along the x/y axes to span a total map of 14.4×10 cm{sup 2}. Results show that absorbed doses measured by our pCVD diamond device are consistent with those calculated by the Treatment Planning System (TPS)

  9. Estimation of absorbed dose in clinical radiotherapy linear accelerator beams: Effect of ion chamber calibration and long-term stability.

    Science.gov (United States)

    Ravichandran, Ramamoorthy; Binukumar, Johnson Pichy; Davis, Cheriyathmanjiyil Antony

    2013-10-01

    The measured dose in water at reference point in phantom is a primary parameter for planning the treatment monitor units (MU); both in conventional and intensity modulated/image guided treatments. Traceability of dose accuracy therefore still depends mainly on the calibration factor of the ion chamber/dosimeter provided by the accredited Secondary Standard Dosimetry Laboratories (SSDLs), under International Atomic Energy Agency (IAEA) network of laboratories. The data related to Nd,water calibrations, thermoluminescent dosimetry (TLD) postal dose validation, inter-comparison of different dosimeter/electrometers, and validity of Nd,water calibrations obtained from different calibration laboratories were analyzed to find out the extent of accuracy achievable. Nd,w factors in Gray/Coulomb calibrated at IBA, GmBH, Germany showed a mean variation of about 0.2% increase per year in three Farmer chambers, in three subsequent calibrations. Another ion chamber calibrated in different accredited laboratory (PTW, Germany) showed consistent Nd,w for 9 years period. The Strontium-90 beta check source response indicated long-term stability of the ion chambers within 1% for three chambers. Results of IAEA postal TL "dose intercomparison" for three photon beams, 6 MV (two) and 15 MV (one), agreed well within our reported doses, with mean deviation of 0.03% (SD 0.87%) (n = 9). All the chamber/electrometer calibrated by a single SSDL realized absorbed doses in water within 0.13% standard deviations. However, about 1-2% differences in absorbed dose estimates observed when dosimeters calibrated from different calibration laboratories are compared in solid phantoms. Our data therefore imply that the dosimetry level maintained for clinical use of linear accelerator photon beams are within recommended levels of accuracy, and uncertainties are within reported values.

  10. Phase II study of concurrent capecitabine and external beam radiotherapy for pain control of bone metastases of breast cancer origin.

    Directory of Open Access Journals (Sweden)

    Yulia Kundel

    Full Text Available Pain from bone metastases of breast cancer origin is treated with localized radiation. Modulating doses and schedules has shown little efficacy in improving results. Given the synergistic therapeutic effect reported for combined systemic chemotherapy with local radiation in anal, rectal, and head and neck malignancies, we sought to evaluate the tolerability and efficacy of combined capecitabine and radiation for palliation of pain due to bone metastases from breast cancer.Twenty-nine women with painful bone metastases from breast cancer were treated with external beam radiation in 10 fractions of 3 Gy, 5 fractions a week for 2 consecutive weeks. Oral capecitabine 700 mg/m(2 twice daily was administered throughout radiation therapy. Rates of complete response, defined as a score of 0 on a 10-point pain scale and no increase in analgesic consumption, were 14% at 1 week, 38% at 2 weeks, 52% at 4 weeks, 52% at 8 weeks, and 48% at 12 weeks. Corresponding rates of partial response, defined as a reduction of at least 2 points in pain score without an increase in analgesics consumption, were 31%, 38%, 28%, 34% and 38%. The overall response rate (complete and partial at 12 weeks was 86%. Side effects were of mild intensity (grade I or II and included nausea (38% of patients, weakness (24%, diarrhea (24%, mucositis (10%, and hand and foot syndrome (7%.External beam radiation with concurrent capecitabine is safe and tolerable for the treatment of pain from bone metastases of breast cancer origin. The overall and complete response rates in our study are unusually high compared to those reported for radiation alone. Further evaluation of this approach, in a randomized study, is warranted.ClinicalTrials.gov NCT01784393NCT01784393.

  11. Fast kilovoltage/megavoltage (kVMV) breathhold cone-beam CT for image-guided radiotherapy of lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wertz, Hansjoerg; Stsepankou, Dzmitry; Blessing, Manuel; Boda-Heggemann, Judit; Hesser, Juergen; Lohr, Frank; Wenz, Frederik [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); Rossi, Michael; Gros, Uwe [Elekta Ltd, Hamburg (Germany); Knox, Chris; Brown, Kevin [Elekta Ltd, Crawley (United Kingdom); Walter, Cornelia, E-mail: hansjoerg.wertz@umm.d [Department of Radiation Oncology, Marienhospital Stuttgart (Germany)

    2010-08-07

    Long image acquisition times of 60-120 s for cone-beam CT (CBCT) limit the number of patients with lung cancer who can undergo volume image guidance under breathhold. We developed a low-dose dual-energy kilovoltage-megavoltage-cone-beam CT (kVMV-CBCT) based on a clinical treatment unit reducing imaging time to {<=}15 s. Simultaneous kVMV-imaging was achieved by dedicated synchronization hardware controlling the output of the linear accelerator (linac) based on detector panel readout signals, preventing imaging artifacts from interference of the linac's MV-irradiation and panel readouts. Optimization was performed to minimize the imaging dose. Single MV-projections, reconstructed MV-CBCT images and images of simultaneous 90{sup 0} kV- and 90{sup 0} MV-CBCT (180{sup 0} kVMV-CBCT) were acquired with different parameters. Image quality and imaging dose were evaluated and compared to kV-imaging. Hardware-based kVMV synchronization resulted in artifact-free projections. A combined 180{sup 0} kVMV-CBCT scan with a total MV-dose of 5 monitor units was acquired in 15 s and with sufficient image quality. The resolution was 5-6 line pairs cm{sup -1} (Catphan phantom). The combined kVMV-scan dose was equivalent to a kV-radiation scan dose of {approx}33 mGy. kVMV-CBCT based on a standard linac is promising and can provide ultra-fast online volume image guidance with low imaging dose and sufficient image quality for fast and accurate patient positioning for patients with lung cancer under breathhold.

  12. Evaluation of a combined respiratory-gating system comprising the TrueBeam linear accelerator and a new real-time tumor-tracking radiotherapy system: a preliminary study.

    Science.gov (United States)

    Shiinoki, Takehiro; Kawamura, Shinji; Uehara, Takuya; Yuasa, Yuki; Fujimoto, Koya; Koike, Masahiro; Sera, Tatsuhiro; Emoto, Yuki; Hanazawa, Hideki; Shibuya, Keiko

    2016-07-08

    A combined system comprising the TrueBeam linear accelerator and a new real-time, tumor-tracking radiotherapy system, SyncTraX, was installed in our institution. The goals of this study were to assess the capability of SyncTraX in measuring the position of a fiducial marker using color fluoroscopic images, and to evaluate the dosimetric and geometric accuracy of respiratory-gated radiotherapy using this combined system for the simple geometry. For the fundamental evaluation of respiratory-gated radiotherapy using SyncTraX, the following were performed:1) determination of dosimetric and positional characteristics of sinusoidal patterns using a motor-driven base for several gating windows; 2) measurement of time delay using an oscilloscope; 3) positional verification of sinusoidal patterns and the pattern in the case of a lung cancer patient; 4) measurement of the half-value layer (HVL in mm AL), effective kVp, and air kerma, using a solid-state detector for each fluoroscopic condition, to determine the patient dose. The dose profile in a moving phantom with gated radiotherapy having a gating window ≤ 4 mm was in good agreement with that under static conditions for each photon beam. The total time delay between TrueBeam and SyncTraX was < 227 ms for each photon beam. The mean of the positional tracking error was < 0.4 mm for sinusoidal patterns and for the pattern in the case of a lung cancer patient. The air-kerma rates from one fluoroscopy direction were 1.93 ± 0.01, 2.86 ± 0.01, 3.92 ± 0.04, 5.28 ± 0.03, and 6.60 ± 0.05 mGy/min for 70, 80, 90, 100, and 110 kV X-ray beams at 80 mA, respectively. The combined system comprising TrueBeam and SyncTraX could track the motion of the fiducial marker and control radiation delivery with reasonable accuracy; therefore, this system provides significant dosimetric improvement. However, patient exposure dose from fluoroscopy was not clinically negligible.

  13. Chemoradiation in cervical cancer with cisplatin and high-dose rate brachytherapy combined with external beam radiotherapy. Results of a phase-II study

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, H.G.; Laban, C.; Puschmann, D.; Koelbl, H. [Dept. of Gynecology, Martin-Luther Univ. Halle-Wittenberg (Germany); Kuhnt, T.; Pigorsch, S.; Dunst, J.; Haensgen, G. [Dept. of Radiotherapy, Martin-Luther Univ. Halle-Wittenberg (Germany)

    2002-07-01

    Background: In 1999, five randomized studies demonstrated that chemoradiation with cisplatin and low-dose rate (LDR) brachytherapy has a benefit in locally advanced cervical cancer and for surgically treated patients in high-risk situations. We evaluated the safety and efficacy of concomitant chemoradiation with cisplatin and high-dose rate (HDR) brachytherapy in patients with cervical cancer. Patients and Method: 27 patients were included in our phase-II trial: 13 locally advanced cases (group A) and 14 adjuvant-therapy patients in high-risk situations (group B). A definitive radiotherapy was performed with 25 fractions of external beam therapy (1.8 Gy per fraction/middle shielded after eleven fractions). Brachytherapy was delivered at HDR schedules with 7 Gy in point A per fraction (total dose 35 Gy) in FIGO Stages IIB-IIIB. The total dose of external and brachytherapy was 70 Gy in point A and 52-54 Gy in point B. All patients in stage IVA were treated without brachytherapy. Adjuvant radiotherapy was performed with external beam radiotherapy of the pelvis with 1.8 Gy single-dose up to 50.4 Gy. Brachytherapy was delivered at HDR schedules with two fractions of 5 Gy only in patients with tumor-positive margins or tumor involvement of the upper vagina. The chemotherapeutic treatment schedule provided six courses of cisplatin 40 mg/m{sup 2} weekly recommended in the randomized studies GOG-120 and -123. Results: A total of 18/27 patients (66.7%) completed all six courses of chemotherapy. Discontinuation of radiotherapy due to therapy-related morbidity was not necessary in the whole study group. G3 leukopenia (29.6%) was the only relevant acute toxicity. There were no differences in toxicity between group A and B. Serious late morbidity occurred in 2/27 patients (7.4%). 12/13 patients (92.3%) with IIB-IVA cervical cancer showed a complete response (CR). 13/14 adjuvant cases (92.8%) are free of recurrence (median follow up: 19.1 months). Conclusion: Concomitant

  14. Adaptive fractionated stereotactic Gamma Knife radiotherapy of meningioma using integrated stereotactic cone-beam-CT and adaptive re-planning (a-gkFSRT)

    Energy Technology Data Exchange (ETDEWEB)

    Stieler, F.; Wenz, F.; Abo-Madyan, Y.; Schweizer, B.; Polednik, M.; Herskind, C.; Giordano, F.A.; Mai, S. [University of Heidelberg, Department of Radiation Oncology, University Medical Center Mannheim, Mannheim (Germany)

    2016-11-15

    The Gamma Knife Icon (Elekta AB, Stockholm, Sweden) allows frameless stereotactic treatment using a combination of cone beam computer tomography (CBCT), a thermoplastic mask system, and an infrared-based high-definition motion management (HDMM) camera system for patient tracking during treatment. We report on the first patient with meningioma at the left petrous bone treated with adaptive fractionated stereotactic radiotherapy (a-gkFSRT). The first patient treated with Gamma Knife Icon at our institute received MR imaging for preplanning before treatment. For each treatment fraction, a daily CBCT was performed to verify the actual scull/tumor position. The system automatically adapted the planned shot positions to the daily position and recalculated the dose distribution (online adaptive planning). During treatment, the HDMM system recorded the intrafractional patient motion. Furthermore, the required times were recorded to define a clinical treatment slot. Total treatment time was around 20 min. Patient positioning needed 0.8 min, CBCT positioning plus acquisition 1.65 min, CT data processing and adaptive planning 2.66 min, and treatment 15.6 min. The differences for the five daily CBCTs compared to the reference are for rotation: -0.59 ± 0.49 /0.18 ± 0.20 /0.05 ± 0.36 and for translation: 0.94 ± 0.52 mm/-0.08 ± 0.08 mm/-1.13 ± 0.89 mm. Over all fractions, an intrafractional movement of 0.13 ± 0.04 mm was observed. The Gamma Knife Icon allows combining the accuracy of the stereotactic Gamma Knife system with the flexibility of fractionated treatment with the mask system and CBCT. Furthermore, the Icon system introduces a new online patient tracking system to the clinical routine. The interfractional accuracy of patient positioning was controlled with a thermoplastic mask and CBCT. (orig.) [German] Das Gamma Knife Icon (Elekta AB, Stockholm, Schweden) ermoeglicht die stereotaktische Behandlung von Patienten mittels Cone-beam-Computertomographie (CBCT

  15. An Innovative Tool for Intraoperative Electron Beam Radiotherapy Simulation and Planning: Description and Initial Evaluation by Radiation Oncologists

    Energy Technology Data Exchange (ETDEWEB)

    Pascau, Javier, E-mail: jpascau@mce.hggm.es [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Departamento de Bioingenieria e Ingenieria Aeroespacial, Universidad Carlos III de Madrid, Madrid (Spain); Santos Miranda, Juan Antonio [Servicio de Oncologia Radioterapica, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Facultad de Medicina, Universidad Complutense de Madrid, Madrid (Spain); Calvo, Felipe A. [Servicio de Oncologia Radioterapica, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Facultad de Medicina, Universidad Complutense de Madrid, Madrid (Spain); Departamento de Oncologia, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Bouche, Ana; Morillo, Virgina [Consorcio Hospitalario Provincial de Castellon, Castellon (Spain); Gonzalez-San Segundo, Carmen [Servicio de Oncologia Radioterapica, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Facultad de Medicina, Universidad Complutense de Madrid, Madrid (Spain); Ferrer, Carlos; Lopez Tarjuelo, Juan [Consorcio Hospitalario Provincial de Castellon, Castellon (Spain); and others

    2012-06-01

    Purpose: Intraoperative electron beam radiation therapy (IOERT) involves a modified strategy of conventional radiation therapy and surgery. The lack of specific planning tools limits the spread of this technique. The purpose of the present study is to describe a new simulation and planning tool and its initial evaluation by clinical users. Methods and Materials: The tool works on a preoperative computed tomography scan. A physician contours regions to be treated and protected and simulates applicator positioning, calculating isodoses and the corresponding dose-volume histograms depending on the selected electron energy. Three radiation oncologists evaluated data from 15 IOERT patients, including different tumor locations. Segmentation masks, applicator positions, and treatment parameters were compared. Results: High parameter agreement was found in the following cases: three breast and three rectal cancer, retroperitoneal sarcoma, and rectal and ovary monotopic recurrences. All radiation oncologists performed similar segmentations of tumors and high-risk areas. The average applicator position difference was 1.2 {+-} 0.95 cm. The remaining cancer sites showed higher deviations because of differences in the criteria for segmenting high-risk areas (one rectal, one pancreas) and different surgical access simulated (two rectal, one Ewing sarcoma). Conclusions: The results show that this new tool can be used to simulate IOERT cases involving different anatomic locations, and that preplanning has to be carried out with specialized surgical input.

  16. Comparison of Pencil beam, Collapsed cone and Monte-Carlo algorithm in radiotherapy treatment planning for 6 MV photon

    CERN Document Server

    Kim, Sung Jin; Kim, Sung Kyu

    2015-01-01

    Treatment planning system calculations in inhomogeneous regions may present significant inaccuracies due to loss of electronic equilibrium. In this study, three different dose calculation algorithms, pencil beam, collapsed cone, and Monte-Carlo, provided by our planning system were compared to assess their impact on the three-dimensional planning of lung and breast cases. A total of five breast and five lung cases were calculated using the PB, CC, and MC algorithms. Planning treatment volume and organs at risk delineation was performed according to our institutions protocols on the Oncentra MasterPlan image registration module, on 0.3 to 0.5 cm computed tomography slices taken under normal respiration conditions. Four intensity-modulated radiation therapy plans were calculated according to each algorithm for each patient. The plans were conducted on the Oncentra MasterPlan and CMS Monaco treatment planning systems, for 6 MV. The plans were compared in terms of the dose distribution in target, OAR volumes, and...

  17. A randomized trial comparing hypofractionated and conventionally fractionated three-dimensional external-beam radiotherapy for localized prostate adenocarcinoma. A report on acute toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Norkus, Darius; Miller, Albert; Kurtinaitis, Juozas; Valuckas, Konstantinas Povilas [Dept. of Radiotherapy, Inst. of Oncology, Vilnius Univ. (Lithuania); Haverkamp, Uwe [Dept. of Radiology, Clemenshospital, Muenster (Germany); Popov, Sergey [Dept. of Radiotherapy, Riga Eastern Hospital, Latvian Oncology Center, Riga (Latvia); Prott, Franz-Josef [Inst. of Radiology and Radiotherapy (RNS), St. Josefs Hospital, Wiesbaden (Germany)

    2009-11-15

    Purpose: to compare acute gastrointestinal (GI) and genitourinary (GU) toxicity between patient groups with localized prostate adenocarcinoma, treated with conventionally fractionated (CFRT) and hypofractionated (HFRT) three-dimensional conformal external-beam radiotherapy (3D-CRT). Patients and methods: 91 patients were enrolled into a randomized study with a minimum follow-up of 3 months. 44 men in the CFRT arm were irradiated with 74 Gy in 37 fractions at 2 Gy per fraction for 7.5 weeks. 47 men in the HFRT arm were treated with 57 Gy in 17 fractions for 3.5 weeks, given as 13 fractions of 3 Gy plus four fractions of 4.5 Gy. The clinical target volume (CTV) included the prostate and the base of seminal vesicles. The CTV-to-PTV (planning target volume) margin was 8-10 mm. Study patients had portal imaging and/or simulation performed on the first fractions and repeated at least weekly. Results: no acute grade 3 or 4 toxicities were observed. The grade 2 GU acute toxicity proportion was significantly lower in the HFRT arm: 19.1% versus 47.7% ({chi}{sup 2}-test, p = 0.003). The grade 2 GU acute toxicity-free survival was significantly better in the HFRT arm (log-rank test, p = 0.008). The median duration of overall GI acute toxicity was shorter with HFRT: 3 compared to 6 weeks with CFRT (median test, p = 0.017). Conclusion: in this first evaluation, the HFRT schedule is feasible and induces acceptable or even lower acute toxicity compared with the toxicities in the CFRT schedule. Extended follow-up is needed to justify this fractionation schedule's safety in the long term. (orig.)

  18. Clinical outcomes of adjuvant external-beam radiotherapy for differentiated thyroid cancer. Results after 874 patient-years of follow-up in the MSDS-trial

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, M. [Haukeland University Hospital, Bergen (Norway). Dept. of Radiology; Pixberg, M.K.; Riemann, B.; Schober, O. [Muenster Univ. (Germany). Dept. of Nuclear Medicine; Schuck, A.; Willich, N. [Muenster Univ. (Germany). Dept. of Radiooncology; Heinecke, A. [Muenster Univ. (Germany). Dept. of Biometrics; Schmid, K.W. [University Hospital of Essen, West German Cancer Center (Germany). Inst. of Pathology and Neuropathology; Dralle, H. [Halle-Wittenberg Univ. (Germany). Dept. of General Surgery

    2009-07-01

    Evaluate the clinical benefit of external beam radiotherapy (RTx) for locally invasive thyroid carcinoma with follicular cell differentiation (DTC). The Multicentre Study on Differentiated Thyroid Cancer (MSDS) was planned as a prospective multicenter trial on the benefit of adjuvant RTx in locally invasive DTC (pT4; UICC 1997) with or without lymph node metastases and no known distant metastases. All patients were treated with thyroidectomy, {sup 131}I-therapy, and TSH-suppression and were randomized to receive additional RTx or not. In 4/2003 the trial became a prospective cohort study after only 45 of then 311 patients had consented to randomization. 351 of 422 patients met the trial's inclusion criteria. Age was 48 {+-} 12 years (mean {+-} SD). 25% were men. Tumours were papillary in 90% and follicular in 10%. Of 47 patients randomized or allocated to RTx, 26 actually received RTx. Mean follow-up was 930 days. In an actual treatment analysis, 96% (25/26) of the RTx-patients reached complete remission (CR) vs. 86% in the non-RTx patients. Recurrences occurred in 0 vs. 3 % of patients: 6 reoperated for regional lymph node metastases, 1 tracheal invasion treated with tracheoplasty, 1 local invasion necessitating laryngectomy, 2 distant metastases (1 lung, 1 lung + bone). Serious chronic RTx toxicity occurred in 1/26 patients. The MSDS trial showed low mortality and recurrence rates and a weak benefit of RTx in terms of local control that did however not reach statistical significance. Routine RTx in locally invasive DTC can no longer be recommended. (orig.)

  19. Updated results of high-dose rate brachytherapy and external beam radiotherapy for locally and locally advanced prostate cancer using the RTOG-ASTRO phoenix definition

    Directory of Open Access Journals (Sweden)

    Antonio C. Pellizzon

    2008-06-01

    Full Text Available PURPOSE: To evaluate the prognostic factors for patients with local or locally advanced prostate cancer treated with external beam radiotherapy (RT and high dose rate brachytherapy (HDR according to the RTOG-ASTRO Phoenix Consensus Conference. MATERIALS AND METHODS: The charts of 209 patients treated between 1997 and 2005 with localized RT and HDR as a boost at the Department of Radiation Oncology, AC Camargo Hospital, Sao Paulo, Brazil were reviewed. Clinical and treatment parameters i.e.: patient's age, Gleason score, clinical stage, initial PSA (iPSA, risk group (RG for biochemical failure, doses of RT and HDR were evaluated. Median age and median follow-up time were 68 and 5.3 years, respectively. Median RT and HDR doses were 45 Gy and 20 Gy. RESULTS: Disease specific survival (DSS at 3.3 year was 94.2%. Regarding RG, for the LR (low risk, IR (intermediate risk and HR (high risk, the DSS rates at 3.3 years were 91.5%, 90.2% and 88.5%, respectively. On univariate analysis prognostic factors related to DSS were RG (p = 0.040, Gleason score ≤ 6 ng/mL (p = 0.002, total dose of HDR ≥ 20 Gy (p < 0.001 On multivariate analysis the only statistical significant predictive factor for biochemical control (bNED was the RG, p < 0.001 (CI - 1.147-3.561. CONCLUSIONS: Although the radiation dose administered to the prostate is an important factor related to bNED, this could not be established with statistical significance in this group of patients. To date , in our own experience, HDR associated to RT could be considered a successful approach in the treatment of prostate cancer.

  20. Cone beam computed tomography: An accurate imaging technique in comparison with orthogonal portal imaging in intensity-modulated radiotherapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Om Prakash Gurjar

    2016-03-01

    Full Text Available Purpose: Various factors cause geometric uncertainties during prostate radiotherapy, including interfractional and intrafractional patient motions, organ motion, and daily setup errors. This may lead to increased normal tissue complications when a high dose to the prostate is administered. More-accurate treatment delivery is possible with daily imaging and localization of the prostate. This study aims to measure the shift of the prostate by using kilovoltage (kV cone beam computed tomography (CBCT after position verification by kV orthogonal portal imaging (OPI.Methods: Position verification in 10 patients with prostate cancer was performed by using OPI followed by CBCT before treatment delivery in 25 sessions per patient. In each session, OPI was performed by using an on-board imaging (OBI system and pelvic bone-to-pelvic bone matching was performed. After applying the noted shift by using OPI, CBCT was performed by using the OBI system and prostate-to-prostate matching was performed. The isocenter shifts along all three translational directions in both techniques were combined into a three-dimensional (3-D iso-displacement vector (IDV.Results: The mean (SD IDV (in centimeters calculated during the 250 imaging sessions was 0.931 (0.598, median 0.825 for OPI and 0.515 (336, median 0.43 for CBCT, p-value was less than 0.0001 which shows extremely statistical significant difference.Conclusion: Even after bone-to-bone matching by using OPI, a significant shift in prostate was observed on CBCT. This study concludes that imaging with CBCT provides a more accurate prostate localization than the OPI technique. Hence, CBCT should be chosen as the preferred imaging technique.

  1. A Study on Stereoscopic X-ray Imaging Data Set on the Accuracy of Real-Time Tumor Tracking in External Beam Radiotherapy.

    Science.gov (United States)

    Esmaili Torshabi, Ahmad; Ghorbanzadeh, Leila

    2017-04-01

    At external beam radiotherapy, stereoscopic X-ray imaging system is responsible as tumor motion information provider. This system takes X-ray images intermittently from tumor position (1) at pretreatment step to provide training data set for model construction and (2) during treatment to control the accuracy of correlation model performance. In this work, we investigated the effect of imaging data points provided by this system on treatment quality. Because some information is still lacking about (1) the number of imaging data points, (2) shooting time for capturing each data point, and also (3) additional imaging dose delivered by this system. These 3 issues were comprehensively assessed at (1) pretreatment step while training data set is gathered for prediction model construction and (2) during treatment while model is tested and reconstructed using new arrival data points. A group of real patients treated with CyberKnife Synchrony module was chosen in this work, and an adaptive neuro-fuzzy inference system was considered as consistent correlation model. Results show that a proper model can be constructed while the number of imaging data points is highly enough to represent a good pattern of breathing cycles. Moreover, a trade-off between the number of imaging data points and additional imaging dose is considered in this study. Since breathing phenomena are highly variable at different patients, the time for taking some of imaging data points is very important, while their absence at that critical time may yield wrong tumor tracking. In contrast, the sensitivity of another category of imaging data points is not high, while breathing is normal and in the control range. Therefore, an adaptive supervision on the implementation of stereoscopic X-ray imaging is proposed to intelligently accomplish shooting process, based on breathing motion variations.

  2. Accelerated hypofractionated adjuvant whole breast radiotherapy with concomitant photon boost after conserving surgery for early stage breast cancer: a prospective evaluation on 463 patients.

    Science.gov (United States)

    Cante, Domenico; Rosa La Porta, Maria; Casanova-Borca, Valeria; Sciacero, Piera; Girelli, Giuseppe; Pasquino, Massimo; Franco, Pierfrancesco; Ozzello, Franca

    2011-01-01

    The current standard therapeutic option for early stage breast cancer (EBC) employs a multimodality treatment approach including conservative surgery, radiotherapy, chemotherapy, and hormone therapy. The most common adjuvant radiotherapeutic strategy consists of external beam radiation therapy (EBRT) delivered to the whole breast using 1.8-2 Gy fractions given five times a week, up to a total dose of 45-50 Gy over a period of 5 weeks. In recent years, altered schedules employing larger dose per fraction delivered in fewer treatment sessions over a shorter overall treatment time began to be explored. We herein present clinical data on accelerated hypofractionated adjuvant whole-breast radiotherapy delivered on a daily basis for a total treatment time of 20 fractions. Between February 2005 and June 2009, a total of 463 patients underwent hypofractionated accelerated adjuvant radiation after conservative surgery for early breast cancer (pathological stage pTis, pT1 or pT2, pN0-N1). The basic course of radiotherapy consisted of 45 Gy, to the whole breast in 20 fractions with 2.25 Gy/fraction; an additional daily boost dose of 0.25 Gy was concomitantly delivered, to the lumpectomy cavity, for an additional total dose of 5 Gy. The cumulative nominal dose was 50 Gy. At follow-up, patients were examined at 3 and 6 months after the end of radiotherapy and twice a year afterward. Toxicity was scored according to the Common Terminology Criteria for Adverse Events, using the Radiation Therapy Oncology Group /European Organization for Research and Treatment of Cancer toxicity scale. Cosmetic results were assessed in agreement with the Harvard criteria. All the 463 patients treated with the accelerated hypofractionated adjuvant whole-breast radiotherapy schedule achieved at least 6 months' follow-up and subsequently were considered for the present analysis. With a median follow-up of 27 months, 5-year DFS is 93.1%. Only three patients experienced disease recurrence: two of them

  3. Calculation of uncertainties in the protocol of dosimetry for Co 60 beams in Radiotherapy; Calculo de incertidumbres en el protocolo de dosimetria para haces de Co 60 en Radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez M, S.; Carrera M, F.; Sanchez S, J. [Hospital Juan Ramon Jimenez, Ronda Norte s/n 21005 Huelva (Spain)

    1998-12-31

    The objective in this work is to show how the uncertainty is possible to know in the determination of the absorbed dose in Co 60 photon beams and to establish in a rational form, tolerance levels for this. It is took as base the spanish protocol of dosimetry in Radiotherapy. We have been centered in a Co 60 beam. We utilized the statistical theory of little samples. We allowed to suggest a new approach about the treatment of the tolerance levels and the uncertainty of the measurement. After two years of experience in the practical hospitable application we have gotten to put around 1 % uncertainty in the absolute dosimetry of the Co 60 beam. The presented protocol allows to execute the accuracy requirements in the determination of absorbed doses. (Author)

  4. Volumetric modulated arc planning for lung stereotactic body radiotherapy using conventional and unflattened photon beams: a dosimetric comparison with 3D technique

    Directory of Open Access Journals (Sweden)

    Zhang Geoffrey G

    2011-11-01

    Full Text Available Abstract Purpose Frequently, three-dimensional (3D conformal beams are used in lung cancer stereotactic body radiotherapy (SBRT. Recently, volumetric modulated arc therapy (VMAT was introduced as a new treatment modality. VMAT techniques shorten delivery time, reducing the possibility of intrafraction target motion. However dose distributions can be quite different from standard 3D therapy. This study quantifies those differences, with focus on VMAT plans using unflattened photon beams. Methods A total of 15 lung cancer patients previously treated with 3D or VMAT SBRT were randomly selected. For each patient, non-coplanar 3D, coplanar and non-coplanar VMAT and flattening filter free VMAT (FFF-VMAT plans were generated to meet the same objectives with 50 Gy covering 95% of the PTV. Two dynamic arcs were used in each VMAT plan. The couch was set at ± 5° to the 0° straight position for the two non-coplanar arcs. Pinnacle version 9.0 (Philips Radiation Oncology, Fitchburg WI treatment planning system with VMAT capabilities was used. We analyzed the conformity index (CI, which is the ratio of the total volume receiving at least the prescription dose to the target volume receiving at least the prescription dose; the conformity number (CN which is the ratio of the target coverage to CI; and the gradient index (GI which is the ratio of the volume of 50% of the prescription isodose to the volume of the prescription isodose; as well as the V20, V5, and mean lung dose (MLD. Paired non-parametric analysis of variance tests with post-tests were performed to examine the statistical significance of the differences of the dosimetric indices. Results Dosimetric indices CI, CN and MLD all show statistically significant improvement for all studied VMAT techniques compared with 3D plans (p Conclusion Besides the advantage of faster delivery times, VMAT plans demonstrated better conformity to target, sharper dose fall-off in normal tissues and lower dose to

  5. Dose enhancement in gold nanoparticle-aided radiotherapy for the therapeutic photon beams using Monte Carlo technique

    Directory of Open Access Journals (Sweden)

    Nitin Ramesh Kakade

    2015-01-01

    Full Text Available Background: Gold nanoparticle (GNP-aided radiation therapy (RT is useful to make the tumor more sensitive to radiation damage because of the enhancement in the dose inside the tumor region. Polymer gel dosimeter (PGD can be a good choice for the physical measurement of dose enhancement produced by GNP inside the gel. Materials and Methods: The present study uses EGSnrc Monte Carlo code to estimate dose enhancement factor (DEF due to the introduction of GNPs inside the PGD at different concentrations (7 and 18 mg Au/g of gel when irradiated by therapeutic X-rays of energy 100 kVp, 150 kVp, 6 MV, and 15 MV. The simulation was also carried out to quantify the dose enhancement in PAGAT gel and tumor for 100 kVp X-rays. Results: For 100 kVp X-rays, average DEF of 1.86 and 2.91 is observed in the PAGAT gel dosimeter with 7 and 18 mg Au/g of gel, respectively. Average DEF of 1.69 and 2.61 is recorded for 150 kVp X-rays with 7 and 18 mg Au/g of gel, respectively. No clinically meaningful DEF was observed for 6 and 15 MV photon beams. Furthermore, the dose enhancement within the PAGAT gel dosimeter and tumor closely matches with each other. Conclusion: The polymer gel dosimetry can be a suitable method of dose estimation and verification for clinical implementation of GNP-aided RT. GNP-aided RT has the potential of delivering high localized tumoricidal dose with significant sparing of normal structures when the treatment is delivered with low energy X-rays.

  6. Effect of dose reduction on image registration and image quality for cone-beam CT in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Loutfi-Krauss, B.; Koehn, J.; Bluemer, N.; Kara, E.; Scherf, C.; Roedel, C.; Ramm, U.; Licher, J. [Universitaetsklinikum Frankfurt, Klinik fuer Strahlentherapie und Onkologie, Frankfurt am Main (Germany); Freundl, K.; Koch, T. [Sozialstiftung Bamberg - MVZ am Bruderwald, Klinik und Praxis fuer Radioonkologie und Strahlentherapie, Bamberg (Germany)

    2014-09-20

    The additional radiation exposure applied to patients undergoing cone-beam computed tomography (CBCT) for image registration in radiation therapy is of great concern. Since a decrease in CBCT dose is linked to a degradation of image quality, the consequences of dose reduction on the registration process have to be investigated. This paper examines image quality and registration of low-contrast structures on an Elekta XVI for the two treatment areas prostate and chest while gradually decreasing the mAs per frame and the number of projections per CBCT to achieve dose reduction. Ideal results for image quality were obtained for 1.6 mAs/frame and 377 projections in prostate scans and 0.63 mAs/frame and 440 projections in chest images. Lower as well as higher total mAs lead to a decrease in image quality. In spite of poor image quality, registration can be successfully performed even for lowest possible settings. The results for registration allow an extensive dose reduction in both treatment areas. Very low mAs, however, do not qualify for clinical use because subjective judgment of the registration process is impossible. Compared to default presets the use of settings for acceptable image quality already permit a decrease in exposure of about 40 % (29.0 to 16.7 mGy) in prostate scans and 60 % (18.3 to 7.7 mGy) in chest scans. (orig.) [German] Die zusaetzliche Strahlenbelastung von Patienten bei der Lagerungskontrolle mit einer Kegelstrahl-Computertomographie (CBCT) in der Strahlentherapie ist nicht zu vernachlaessigen. Die Reduzierung der Dosis durch das CBCT ist mit einer Verschlechterung der Bildqualitaet verbunden. Aus diesem Grund ist die Untersuchung der Effekte einer Dosisreduktion von grosser Bedeutung. Diese Arbeit untersucht die Bildqualitaet und Bildregistrierung in Bereichen niedrigen Kontrasts mit einem Kegelstrahl CT der Firma Elekta. Betrachtet werden die Behandlungsregionen Prostata und Thorax. Die Dosisreduktion wird durch stufenweise Verringerung der

  7. SU-E-J-32: Dosimetric Evaluation Based On Pre-Treatment Cone Beam CT for Spine Stereotactic Body Radiotherapy: Does Region of Interest Focus Matter?

    Energy Technology Data Exchange (ETDEWEB)

    Magnelli, A; Xia, P [The Cleveland Clinic Foundation, Cleveland, OH (United States)

    2015-06-15

    Purpose: Spine stereotactic body radiotherapy requires very conformal dose distributions and precise delivery. Prior to treatment, a KV cone-beam CT (KV-CBCT) is registered to the planning CT to provide image-guided positional corrections, which depend on selection of the region of interest (ROI) because of imperfect patient positioning and anatomical deformation. Our objective is to determine the dosimetric impact of ROI selections. Methods: Twelve patients were selected for this study with the treatment regions varied from C-spine to T-spine. For each patient, the KV-CBCT was registered to the planning CT three times using distinct ROIs: one encompassing the entire patient, a large ROI containing large bony anatomy, and a small target-focused ROI. Each registered CBCT volume, saved as an aligned dataset, was then sent to the planning system. The treated plan was applied to each dataset and dose was recalculated. The tumor dose coverage (percentage of target volume receiving prescription dose), maximum point dose to 0.03 cc of the spinal cord, and dose to 10% of the spinal cord volume (V10) for each alignment were compared to the original plan. Results: The average magnitude of tumor coverage deviation was 3.9%±5.8% with external contour, 1.5%±1.1% with large ROI, 1.3%±1.1% with small ROI. Spinal cord V10 deviation from plan was 6.6%±6.6% with external contour, 3.5%±3.1% with large ROI, and 1.2%±1.0% with small ROI. Spinal cord max point dose deviation from plan was: 12.2%±13.3% with external contour, 8.5%±8.4% with large ROI, and 3.7%±2.8% with small ROI. Conclusion: A small ROI focused on the target results in the smallest deviation from planned dose to target and cord although rotations at large distances from the targets were observed. It is recommended that image fusion during CBCT focus narrowly on the target volume to minimize dosimetric error. Improvement in patient setups may further reduce residual errors.

  8. Spine Stereotactic Body Radiotherapy Utilizing Cone-Beam CT Image-Guidance With a Robotic Couch: Intrafraction Motion Analysis Accounting for all Six Degrees of Freedom

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, Derek [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario (Canada); British Columbia Cancer Agency, The Sindi Hawkins Cancer Centre for the Southern Interior, Kelowna (Canada); Lochray, Fiona; Korol, Renee; Davidson, Melanie; Wong, C. Shun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario (Canada); Ma, Lijun [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States); Sahgal, Arjun, E-mail: Arjun.sahgal@rmp.uhn.on.ca [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario (Canada); Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto (Canada)

    2012-03-01

    Purpose: To evaluate the residual setup error and intrafraction motion following kilovoltage cone-beam CT (CBCT) image guidance, for immobilized spine stereotactic body radiotherapy (SBRT) patients, with positioning corrected for in all six degrees of freedom. Methods and Materials: Analysis is based on 42 consecutive patients (48 thoracic and/or lumbar metastases) treated with a total of 106 fractions and 307 image registrations. Following initial setup, a CBCT was acquired for patient alignment and a pretreatment CBCT taken to verify shifts and determine the residual setup error, followed by a midtreatment and posttreatment CBCT image. For 13 single-fraction SBRT patients, two midtreatment CBCT images were obtained. Initially, a 1.5-mm and 1 Degree-Sign tolerance was used to reposition the patient following couch shifts which was subsequently reduced to 1 mm and 1 Degree-Sign degree after the first 10 patients. Results: Small positioning errors after the initial CBCT setup were observed, with 90% occurring within 1 mm and 97% within 1 Degree-Sign . In analyzing the impact of the time interval for verification imaging (10 {+-} 3 min) and subsequent image acquisitions (17 {+-} 4 min), the residual setup error was not significantly different (p > 0.05). A significant difference (p = 0.04) in the average three-dimensional intrafraction positional deviations favoring a more strict tolerance in translation (1 mm vs. 1.5 mm) was observed. The absolute intrafraction motion averaged over all patients and all directions along x, y, and z axis ({+-} SD) were 0.7 {+-} 0.5 mm and 0.5 {+-} 0.4 mm for the 1.5 mm and 1 mm tolerance, respectively. Based on a 1-mm and 1 Degree-Sign correction threshold, the target was localized to within 1.2 mm and 0.9 Degree-Sign with 95% confidence. Conclusion: Near-rigid body immobilization, intrafraction CBCT imaging approximately every 15-20 min, and strict repositioning thresholds in six degrees of freedom yields minimal intrafraction motion

  9. Respiratory motion management using audio-visual biofeedback for respiratory-gated radiotherapy of synchrotron-based pulsed heavy-ion beam delivery

    Energy Technology Data Exchange (ETDEWEB)

    He, Pengbo; Ma, Yuanyuan; Huang, Qiyan; Yan, Yuanlin [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); School of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Qiang, E-mail: liqiang@impcas.ac.cn; Liu, Xinguo; Dai, Zhongying; Zhao, Ting; Fu, Tingyan; Shen, Guosheng [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-11-01

    Purpose: To efficiently deliver respiratory-gated radiation during synchrotron-based pulsed heavy-ion radiotherapy, a novel respiratory guidance method combining a personalized audio-visual biofeedback (BFB) system, breath hold (BH), and synchrotron-based gating was designed to help patients synchronize their respiratory patterns with synchrotron pulses and to overcome typical limitations such as low efficiency, residual motion, and discomfort. Methods: In-house software was developed to acquire body surface marker positions and display BFB, gating signals, and real-time beam profiles on a LED screen. Patients were prompted to perform short BHs or short deep breath holds (SDBH) with the aid of BFB following a personalized standard BH/SDBH (stBH/stSDBH) guiding curve or their own representative BH/SDBH (reBH/reSDBH) guiding curve. A practical simulation was performed for a group of 15 volunteers to evaluate the feasibility and effectiveness of this method. Effective dose rates (EDRs), mean absolute errors between the guiding curves and the measured curves, and mean absolute deviations of the measured curves were obtained within 10%–50% duty cycles (DCs) that were synchronized with the synchrotron’s flat-top phase. Results: All maneuvers for an individual volunteer took approximately half an hour, and no one experienced discomfort during the maneuvers. Using the respiratory guidance methods, the magnitude of residual motion was almost ten times less than during nongated irradiation, and increases in the average effective dose rate by factors of 2.39–4.65, 2.39–4.59, 1.73–3.50, and 1.73–3.55 for the stBH, reBH, stSDBH, and reSDBH guiding maneuvers, respectively, were observed in contrast with conventional free breathing-based gated irradiation, depending on the respiratory-gated duty cycle settings. Conclusions: The proposed respiratory guidance method with personalized BFB was confirmed to be feasible in a group of volunteers. Increased effective dose

  10. Normal Tissue Complication Probability (NTCP) modeling of late rectal bleeding following external beam radiotherapy for prostate cancer: A Test of the QUANTEC-recommended NTCP model

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Mitchell; Agranovich, Alexander; Karvat, Anand; Kwan, Winkle (Fraser Valley Centre, British Columbia Cancer Centre, Surrey, BC (Canada)); Moiseenko, Vitali (Vancouver Centre, British Columbia Cancer Agency, Vancouver, BC (Canada)); Saleh, Ziad H.; Apte, Aditya A.; Deasy, Joseph O. (Dept. of Radiation Oncology and the Mallinckrodt Inst. of Radiology, Washington Univ., St. Louis, MO (United States)), e-mail: deasyj@mskcc.org

    2010-10-15

    Purpose/background. Validating a predictive model for late rectal bleeding following external beam treatment for prostate cancer would enable safer treatments or dose escalation. We tested the normal tissue complication probability (NTCP) model recommended in the recent QUANTEC review (quantitative analysis of normal tissue effects in the clinic). Material and methods. One hundred and sixty one prostate cancer patients were treated with 3D conformal radiotherapy for prostate cancer at the British Columbia Cancer Agency in a prospective protocol. The total prescription dose for all patients was 74 Gy, delivered in 2 Gy/fraction. 159 3D treatment planning datasets were available for analysis. Rectal dose volume histograms were extracted and fitted to a Lyman-Kutcher-Burman NTCP model. Results. Late rectal bleeding (>grade 2) was observed in 12/159 patients (7.5%). Multivariate logistic regression with dose-volume parameters (V50, V60, V70, etc.) was non-significant. Among clinical variables, only age was significant on a Kaplan-Meier log-rank test (p=0.007, with an optimal cut point of 77 years). Best-fit Lyman-Kutcher-Burman model parameters (with 95% confidence intervals) were: n = 0.068 (0.01, +infinity); m =0.14 (0.0, 0.86); and TD50 81 (27, 136) Gy. The peak values fall within the 95% QUANTEC confidence intervals. On this dataset, both models had only modest ability to predict complications: the best-fit model had a Spearman's rank correlation coefficient of rs = 0.099 (p = 0.11) and area under the receiver operating characteristic curve (AUC) of 0.62; the QUANTEC model had rs=0.096 (p= 0.11) and a corresponding AUC of 0.61. Although the QUANTEC model consistently predicted higher NTCP values, it could not be rejected according to the chi2 test (p = 0.44). Conclusions. Observed complications, and best-fit parameter estimates, were consistent with the QUANTEC-preferred NTCP model. However, predictive power was low, at least partly because the rectal dose

  11. Radiotherapy and Brachytherapy : Proceedings of the NATO Advanced Study Institute on Physics of Modern Radiotherapy & Brachytherapy

    CERN Document Server

    Lemoigne, Yves

    2009-01-01

    This volume collects a series of lectures presented at the tenth ESI School held at Archamps (FR) in November 2007 and dedicated to radiotherapy and brachytherapy. The lectures focus on the multiple facets of radiotherapy in general, including external radiotherapy (often called teletherapy) as well as internal radiotherapy (called brachytherapy). Radiotherapy strategy and dose management as well as the decisive role of digital imaging in the associated clinical practice are developed in several articles. Grouped under the discipline of Conformal Radiotherapy (CRT), numerous modern techniques, from Multi-Leaf Collimators (MLC) to Intensity Modulated RadioTherapy (IMRT), are explained in detail. The importance of treatment planning based upon patient data from digital imaging (Computed Tomography) is also underlined. Finally, despite the quasi- totality of patients being presently treated with gamma and X-rays, novel powerful tools are emerging using proton and light ions (like carbon ions) beams, bound to bec...

  12. Organ-confined prostate carcinoma radiation brachytherapy compared with external either photon- or hadron-beam radiation therapy. Just a short up-to-date.

    Science.gov (United States)

    Alberti, C

    2011-07-01

    Both low dose rate (LDR) permanent either 1251 or 103Pd seed implant and high dose rate (HDR) 1921r temporary implant are an excellent way to release high dose of ionizing radiations to cancerous lesions while significantly sparing the surrounding healthy tissues. Therefore, the radiation brachytherapy, among the established treatment options of organ-confined prostate carcinoma--interstitial radiofrequency, high intensity focused ultrasound, cryotherapy--has gained large acceptance in the last decades. The LDR permanent interstitial radioactive seed implantation is often used as monotherapy for low risk prostate carcinoma whereas the HDR temporary implant may useful to treat intermediate-to-high risk prostate tumors as a radiation boost to combined external beam radiation therapy (EBRT). On the other hand, with recent refinement of EBRT techniques--either three-dimensional conformal- or intensity-modulated radiotherapy, cyber-knife radiosurgery with even 4D-high resolution image-guided tracking--high doses of X-rays may be precisely delivered to prostate malignant lesions without increasing toxicity for surrounding normal structures. Also hadron therapy is an increasingly successful technique that allows the release of effective energy of protons (H+), neutrons or carbon ions (6(12)C) to the limited extent of the cancerous target site, thus destroying malignant lesion with millimetric precision--just as bloodless surgery--while less damaging the neighbouring healthy tissues. Looking to the near future, even more effective oncotherapy modality appears to be the use of antiprotons because of their highly confined energy deposition at well defined body dept around the annihilation point in contact with protons of the ordinary matter, so targeting only a very limited body volume.

  13. Radioluminescence characterization of in situ x-ray nanodosimeters: Potential real-time monitors and modulators of external beam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Souris, Jeffrey S.; La Riviere, Patrick; Chen, Chin-Tu [Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Cheng, Shih-Hsun; Chen, Nai-Tzu; Lo, Leu-Wei, E-mail: lwlo@nhri.org.tw [Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan, Mioli 35053, Taiwan (China); Pelizzari, Charles [Deaprtment of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States)

    2014-11-17

    Europium-doped yttrium oxide (Y{sub 2}O{sub 3}:Eu) has garnered considerable interest recently for its use as a highly efficient, red phosphor in a variety of lighting applications that include fluorescent lamps, plasma, and field emission display panels, light emitting diodes (LEDs), and lasers. In the present work, we describe the development of Y{sub 2}O{sub 3}:Eu nanoparticles for a very different application: in situ, in vivo x-ray dosimetry. Spectroscopic analyses of these nanoparticles during x-ray irradiation reveal surprisingly bright and stable radioluminescence at near-infrared wavelengths, with markedly linear response to changes in x-ray flux and energy. Monte Carlo modeling of incident flux and broadband, wide-field imaging of mouse phantoms bearing both Y{sub 2}O{sub 3}:Eu nanoparticles and calibrated LEDs of similar spectral emission demonstrated significant transmission of radioluminescence, in agreement with spectroscopic studies; with approximately 15 visible photons being generated for every x-ray photon incident. Unlike the dosimeters currently employed in clinical practice, these nanodosimeters can sample both dose and dose rate rapidly enough as to provide real-time feedback for x-ray based external beam radiotherapy (EBRT). The technique's use of remote sensing and absence of supporting structures enable perturbation-free dosing of the targeted region and complete sampling from any direction. With the conjugation of pathology-targeting ligands onto their surfaces, these nanodosimeters offer a potential paradigm shift in the real-time monitoring and modulation of delivered dose in the EBRT of cancer in situ.

  14. Genome-wide transcription responses to synchrotron microbeam radiotherapy.

    Science.gov (United States)

    Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

    2012-10-01

    The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam.

  15. Radiotherapy; Strahlentherapie

    Energy Technology Data Exchange (ETDEWEB)

    Wannenmacher, M. [Heidelberg Univ., Mannheim (Germany). Abt. fuer Klinische Radiologie; Debus, J. [Univ. Heidelberg (Germany). Abt. Radioonkologie und Strahlentherapie; Wenz, F. (eds.) [Universitaetsklinikum Mannheim (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    2006-07-01

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

  16. A framework for inverse planning of beam-on times for 3D small animal radiotherapy using interactive multi-objective optimization

    NARCIS (Netherlands)

    Balvert, Marleen; van Hoof, S.J.; Granton, Patrick V.; Trani, Daniela; den Hertog, Dick; Hoffmann, A.L.; Verhaegen, Frank

    2015-01-01

    Advances in precision small animal radiotherapy hardware enable the delivery of increasingly complicated dose distributions on the millimeter scale. Manual creation and evaluation of treatment plans becomes difficult or even infeasible with an increasing number of degrees of freedom for dose deliver

  17. The short and long term effects of intraoperative electron beam radiotherapy (IORT) on thoracic organs after pneumonectomy an experimental study in the canine model

    NARCIS (Netherlands)

    de Boer, Willem; Mehta, DM; Timens, W; Hoekstra, HJ

    1999-01-01

    Purpose: The tolerance of mediastinal structures and thoracic organs to intraoperative radiotherapy (IORT) was investigated in the canine model. Methods and Materials: Twenty-two adult beagles divided into three groups were subjected to a left pneumonectomy and IORT (10 MeV electrons) at doses of 20

  18. 概率安全评价法在放疗过程控制管理中的应用研究%Probabilistic safety assessment method in the application of external beam radiotherapy process control management study

    Institute of Scientific and Technical Information of China (English)

    胡睿; 王石; 吴锦昌; 沈丹青; 吴朝霞

    2014-01-01

    Objective To study the probability safety assessment to analyze and evaluate radiation error risk in the external beam radiotherapy,so as to establish and strengthen the control and management of the radiotherapy process,continuous improvement of quality control and quality management.Methods To build the whole of radiotherapy flow chart and process tree,using the decision tree model to determine critical control points in the whole process,making risk assessment chart and analyzing 4 patients with potential safety hazards error.Results The whole process is divided into 22 missions in 3 functional areas,the entire cover 15 branches and 59 key and 11 key control point.The enumeration of error as risks and critical control points has certain correlation.Conclusions Probabilistic safety assessment method have strengthened manage,analyze and control to risk,and all these provide the basis for developing and improving radiotherapy process control management.Radiotherapy quality management for future multidisciplinary and high-level management personnel who take up provides a prospective study.%目的 利用概率安全评价法分析和评估放疗过程中患者的误照风险,从而建立和加强放疗过程控制管理,持续改进QA和QC.方法 对整个放疗全程建立流程图和过程树图,利用判别树模型确定流程中误照风险的关键控制点,制定风险评估表并结合4例潜在误照安全隐患进行判定分析.结果 将整个流程分为3个功能区22个任务,全程涵盖15个分支59个关键操作和11个关键控制点.列举的误照隐患与关键点具有一定相关性.结论 概率安全评价法有利于对误照风险进行分析、管理和控制,为制定和改善放疗过程控制管理提供依据,并对未来多学科和高层次管理人员参与放疗的质量管理提供前瞻性研究方法.

  19. Evaluating repetitive 18F-fluoroazomycin-arabinoside (18FAZA) PET in the setting of MRI guided adaptive radiotherapy in cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Schuetz, Matthias; Kommata, Spyridoula; Lukic, Dobrica; Dudczak, Robert; Kletter, Kurt; Karanikas, Georgios (Dept. of Nuclear Medicine, Medical Univ. of Vienna/AKH Wien (Austria)), E-mail: barbara.bachtiary@meduniwien.ac.at; Schmid, Maximilian P.; Poetter, Richard; Georg, Dietmar; Dimopoulos, Johannes; Bachtiary, Barbara (Dept. of Radiotherapy, Medical Univ. of Vienna/AKH Wien (Austria))

    2010-10-15

    Background. The aim of this pilot study was to assess tumour hypoxia in patients with cervical cancer before, during and after combined radio-chemotherapy and Magnetic Resonance Imaging (MRI) guided brachytherapy (BT) by use of the hypoxia Positron Emission Tomography (PET) tracer 18F-fluoroazomycin-arabinoside (18FAZA ). Material and methods. Fifteen consecutive patients with locally advanced cervical cancer referred for definitive radiotherapy (RT) were included in an approved clinical protocol. Stage distribution was 3 IB1, 1 IB2, 10 IIB, 1 IIIB, tumour volume was 55 cm3 (+/- 67, SD). Dynamic and static 18FAZA -PET scans were performed before, during and after external beam therapy (EBRT) and image guided BT +/- concomitant cisplatin. Dose was prescribed to the individual High Risk Clinical Target Volume (HR CTV) taking into account the dose volume constraints for adjacent organs at risk. Results. Five patients had visually identifiable tumours on 18FAZA -PET scans performed prior to radio-chemotherapy and four patients before brachytherapy. One of five 18FAZA PET positive patients had incomplete remission three months after RT, one had regional recurrence. Four of ten 18FAZA-PET negative patients developed distant metastases. The one patient with incomplete remission received 69 Gy (D90) in the HR CTV, whereas all other patients received mean 99 Gy (+/-12, SD). Conclusion. PET imaging with 18FAZA is feasible in patients with cancer of the uterine cervix. However, its predictive and prognostic value remains to be clarified. This applies in particular for the additional value of 18FAZA-PET compared to morphologic repetitive MRI within the setting of image guided high dose radiotherapy which may contribute to overcome hypoxia related radioresistance.

  20. Radiotherapy and skin tumors; Radiotherapie et tumeurs curanees

    Energy Technology Data Exchange (ETDEWEB)

    Calitchi, E.; KIrova, Y.; Le bourgeois, J.P. [Hopital Henri-Mondor, 94 - Creteil (France)

    1998-09-01

    Radiotherapy plays an important role in treatment of skin tumours. For skin carcinomas, external irradiation (kilo-voltage X-rays or electrons according to clinical characteristics) is more valuable than interstitial brachytherapy, which is recommended for tumours of the lip and of the nasal vestibule. In mycosis fungoides, total cutaneous electron beam radiation therapy is efficient for patients with limited superficial plaques. In the classical form of Kaposi`s sarcoma, radiotherapy can achieve local control-whereas it obtains good palliative results in the epidemic form. (author)

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

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    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.

  2. Monte Carlo study for designing a dedicated “D”-shaped collimator used in the external beam radiotherapy of retinoblastoma patients

    Energy Technology Data Exchange (ETDEWEB)

    Mayorga, P. A. [FISRAD S.A.S., CR 64 A No. 22 - 41, Bogotá D C (Colombia); Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain); Brualla, L.; Sauerwein, W. [NCTeam, Strahlenklinik, Universitätsklinikum Essen, Hufelandstraße 55, D-45122 Essen (Germany); Lallena, A. M., E-mail: lallena@ugr.es [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain)

    2014-01-15

    Purpose: Retinoblastoma is the most common intraocular malignancy in the early childhood. Patients treated with external beam radiotherapy respond very well to the treatment. However, owing to the genotype of children suffering hereditary retinoblastoma, the risk of secondary radio-induced malignancies is high. The University Hospital of Essen has successfully treated these patients on a daily basis during nearly 30 years using a dedicated “D”-shaped collimator. The use of this collimator that delivers a highly conformed small radiation field, gives very good results in the control of the primary tumor as well as in preserving visual function, while it avoids the devastating side effects of deformation of midface bones. The purpose of the present paper is to propose a modified version of the “D”-shaped collimator that reduces even further the irradiation field with the scope to reduce as well the risk of radio-induced secondary malignancies. Concurrently, the new dedicated “D”-shaped collimator must be easier to build and at the same time produces dose distributions that only differ on the field size with respect to the dose distributions obtained by the current collimator in use. The scope of the former requirement is to facilitate the employment of the authors' irradiation technique both at the authors' and at other hospitals. The fulfillment of the latter allows the authors to continue using the clinical experience gained in more than 30 years. Methods: The Monte Carlo codePENELOPE was used to study the effect that the different structural elements of the dedicated “D”-shaped collimator have on the absorbed dose distribution. To perform this study, the radiation transport through a Varian Clinac 2100 C/D operating at 6 MV was simulated in order to tally phase-space files which were then used as radiation sources to simulate the considered collimators and the subsequent dose distributions. With the knowledge gained in that study, a new

  3. Brachytherapy versus radical hysterectomy after external beam chemoradiation: a non-randomized matched comparison in IB2-IIB cervical cancer patients

    Directory of Open Access Journals (Sweden)

    Flores Vladimir

    2009-02-01

    Full Text Available Abstract Background A current paradigm in the treatment of cervical cancer with radiation therapy is that intracavitary brachytherapy is an essential component of radical treatment. This is a matched retrospective comparison of the results of treatment in patients treated with external beam chemoradiation (EBRT-CT and radical hysterectomy versus those treated with identical chemoradiation followed by brachytherapy. Methods In this non-randomized comparison EBRT-CT protocol was the same in both groups of 40 patients. In the standard treated patients, EBRT-CT was followed by one or two intracavitary Cesium (low-dose rate applications within 2 weeks of finishing external radiation to reach a point A dose of at least 85 Gy. In the surgically treated patients, radical hysterectomy with bilateral pelvic lymph node dissection and para-aortic lymph node sampling were performed within 7 weeks after EBRT-CT. Response, toxicity and survival were evaluated. Results A total of 80 patients were analyzed. The patients receiving EBRT-CT and surgery were matched with the standard treated cases. There were no differences in the clinicopathological characteristics between groups or in the delivery of EBRT-CT. The pattern of acute and late toxicity differed. Standard treated patients had more chronic proctitis while the surgically treated had acute complications of surgery and hydronephrosis. At a maximum follow-up of 60 months, median follow-up 26 (2–31 and 22 (3–27 months for the surgery and standard therapy respectively, eight patients per group have recurred and died. The progression free and overall survival are the same in both groups. Conclusion The results of this study suggest that radical hysterectomy can be used after EBRT-CT without compromising survival in FIGO stage IB2-IIB cervical cancer patients in settings were brachytherapy is not available. A randomized study is needed to uncover the value of surgery after EBRT-CT.

  4. Incidence of primary hypothyroidism in patients exposed to therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland

    Directory of Open Access Journals (Sweden)

    B A Laway

    2012-01-01

    Full Text Available Introduction: Hypothyroidism is a known consequence of external-beam radiotherapy to the neck encompassing a part or whole of the thyroid gland. In this non-randomized prospective study, we have tried to evaluate the response of the thyroid gland to radiation by assessing thyroid function before irradiation and at regular intervals after irradiation. Aims and Objectives: The aim of this study were to assess in the cancer patients, who were exposed to the therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland: the incidence of primary hypothyroidism, the time required to become hypothyroid, any relation between the total dose for the development of hypothyroidism, and whether there are any patient or treatment-related factors that are predictive for the development of hypothyroidism, including the use of concurrent chemotherapy. Materials and Methods: This non-randomized, prospective study was conducted for a period of 2 years in which thyroid function was assessed in 59 patients (cases of head and neck cancer, breast cancer, lymphoma patients and other malignancies, who had received radiotherapy to the neck region. 59 euthyroid healthy patients (controls were also taken, who had not received the neck irradiation. These patients/controls were assessed periodically for 2 years. Results: The incidence of hypothyroidism after external beam radiation therapy (EBRT to neck where radiation portals include part or whole of the thyroid gland was 16.94%, seven cases had subclinical hypothyroidism (11.86% and three cases had clinical hypothyroidism (5.08%. Mean time for development of hypothyroidism was 4.5 months. There was no effect of age, gender, primary tumor site, radiation dose and chemotherapy, whether neoadjuvant or concurrent with the development of hypothyroidism. Conclusion: In summary, we found that thyroid dysfunction is a prevalent, yet easily treatable source of morbidity in patients

  5. Preoperative oxaliplatin, capecitabine, and external beam radiotherapy in patients with newly diagnosed, primary operable, cT3NxMo, low rectal cancer. A phase II study

    Energy Technology Data Exchange (ETDEWEB)

    Oefner, Dietmar [Paracelsus Private Medical Univ., Salzburg (Austria). Dept. of Surgery; Innsbruck Medical Univ. (Austria). Dept. of Visceral, Transplant and Thoracic Surgery; DeVries, Alexander F. [Feldkirch Hospital (Austria). Dept. of Radio-Oncology; Schaberl-Moser, Renate [Medical Univ. Graz (AT). Div. of Oncology] (and others)

    2011-02-15

    Purpose: In patients with locally advanced rectal cancer (LARC), preoperative chemoradiation is known to improve local control, and down-staging of the tumor serves as a surrogate for survival. Intensification of the systemic therapy may lead to higher downstaging rates and, thus, enhance survival. This phase II study investigated the efficacy and safety of preoperative capecitabine and oxaliplatin in combination with radiotherapy. Patients and Methods: Patients with LARC of the mid and lower rectum, T3NxM0 staged by MRI received radiotherapy (total dose 45 Gy) in combination with oral capecitabine (825 mg/m{sup 2} twice a day on radiotherapy days; weeks 1-4) and oxaliplatin 50 mg/m{sup 2} intravenously (days 1, 8, 15, and 22). Efficacy was evaluated as rate of tumor down-categorization at the T level. Results: A total of 59 patients were enrolled (19 women, 40 men; median age of 61 years) and all were evaluable for efficacy and toxicity. Down-categorization at the T level was observed in 53% with pathological complete response in 6 patients (10%). Actual total radiotherapy, oxaliplatin and capecitabine doses received were 97%, 90%, and 93% of the protocol-specified preplanned doses, respectively. Grade 3/4 toxicity was observed in 15 patients (25%). The most frequent was diarrhea (12%). Conclusions: Preoperative chemoradiation with capecitabine and oxaliplatin is feasible in patients with MRI-proven cT3 LARC. The only clinically relevant toxicity was diarrhea. Overall, efficacy of the multimodality treatment was good, but not markedly exceeding that of 5-FU- or capecitabine-based chemoradiation approaches. (orig.)

  6. Report on EUROMET.RI(I)-K1 and EUROMET.RI(I)-K4 (EUROMET project no. 813): Comparison of air kerma and absorbed dose to water measurements of {sup 60}Co radiation beams for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Csete, I. [National Office of Measures (OMH) - pilot laboratory and corresponding author (Hungary); Leiton, A.G. [Research Centre for Energy, Environment and Technology (CMRI-CIEMAT) (Spain); Sochor, V. [Czech Metrology Institute (CMI) (Czech Republic); Lapenas, A. [Latvian National Metrology Center (LNMC-RMTC) (Latvia); Grindborg, J.E. [Swedish Radiation Protection Authority (SSI) (Sweden); Jokelainen, I. [Radiation and Nuclear Safety Authority (STUK) (Finland); Bjerke, H. [Norwegian Radiation Protection Authority (NRPA) (Norway); Dobrovodsky, J. [Slovak Institute of Metrology (SMU) (Slovakia); Megzifene, A. [International Atomic Energy Agency, IAEA, Vienna (Austria); Hourdakis, C.J. [Hellenic Atomic Energy Committee (HAEC-HIRCL) (Greece); Ivanov, R. [National Centre of Metrology (NCM) (Bulgaria); Vekic, B. [Rudjer Boskovic Institute (IRB) (Croatia); Kokocinski, J. [Central Office of Measures (GUM) (Poland); Cardoso, J. [Institute for Nuclear Technology (ITN-LMRIR) (Portugal); Buermann, L. [Physikalisch Technische Bundesanstalt (PTB) (Germany); Tiefenboeck, W. [Bundesamt fur Eich und Vermesungswesen (BEV) (Austria); Stucki, G. [17 Bundesamt fur Metrologie (METAS) (Switzerland); Van Dijk, E. [NMi Van Swinden Laboratorium (NMi) (Netherlands); Toni, M.P. [ENEA-CR Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (ENEA) (Italy); Minniti, R. [20 National Institute of Standards and Technology (NIST) (United States); McCaffrey, J.P. [National Research Council Canada (NRC) (Canada); Silva, C.N.M. [National Metrology Laboratory of Ionizing Radiation (LNMRI-IRD) (Brazil); Kharitonov, I. [D I Mendeleyev Institute for Metrology (VNIIM) (RU); Webb, D. [Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) (Australia); Saravi, M. [National Atomic Energy Commission (CNEA-CAE) (Argentina); Delaunay, F. [Laboratoire National Henri Becquerel (LNE-LNHB) (France)

    2010-06-15

    The results of an unprecedented international effort involving 26 countries are reported. The EUROMET.RI(I)-K1 and EUROMET.RI(I)-K4 key comparisons were conducted with the goal of supporting the relevant calibration and measurement capabilities (CMC) planned for publication by the participant laboratories. The measured quantities were the air kerma (K{sub air}) and the absorbed dose to water (Dw) in {sup 60}Co radiotherapy beams. The comparison was conducted by the pilot laboratory MKEH (Hungary), in a star-shaped arrangement from January 2005 to December 2008. The calibration coefficients of four transfer ionization chambers were measured using two electrometers. The largest deviation between any two calibration coefficients for the four chambers in terms of air kerma and absorbed dose to water was 2.7% and 3.3% respectively. An analysis of the participant uncertainty budgets enabled the calculation of degrees of equivalence (DoE), in terms of the deviations of the results and their associated uncertainties. As a result of this EUROMET project 813 comparison, the BIPM key comparison database (KCDB) will include eleven new Kair and fourteen new D{sub w} DoE values of European secondary standard dosimetry laboratories (SSDLs), and the KCDB will be updated with the new DoE values of the other participant laboratories. The pair-wise degrees of equivalence of participants were also calculated. In addition to assessing calibration techniques and uncertainty calculations of the participants, these comparisons enabled the experimental determinations of N{sub Dw}/N{sub Kair} ratios in the {sup 60}Co gamma radiation beam for the four radiotherapy transfer chambers. (authors)

  7. Contribution to the planning and dosimetry of photon beams applied to radiosurgery and stereotactic radiotherapy; Contribuicao ao planejamento e a dosimetria de feixes de fotons aplicados a radiocirurgia e a radioterapia estereotaxica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Walter Menezes

    2003-08-15

    Radiosurgery and stereotactic radiotherapy are irradiation techniques that use small diameter photon beams for treating intracranial lesions such as pituitary adenomas, acoustic tumors and arterio-venous malformations which are inaccessible for surgery. These treatment techniques are characterized by the use of very small radiation beams which deliver a precisely measured dose to the target volume, while sparing the surrounding healthy tissue. Treatment can be performed by using multiple {sup 60}Co gamma-ray sources (in the so-called 'Gamma Knife'), charged particles or X-ray beams produced by linear accelerators. The prescribed dose can be given in a single session or in multiple fractions, as in conventional radiotherapy. The success of the treatment depends, among other factors, of the accurate determination of the parameters that characterize the radiation beam produced by the equipment, as well as, of a well designed quality assurance program. In this study, the dosimetric parameters of a set of collimating cones of a Radionics{sup TM} treatment system applied to two 6 MV- photon beams (Clinac 600C - Varian{sup TM}, and Mevatron MD2 - Siemens{sup TM}) were evaluated by using a water filled PMMA simulator. Measurements were carried out for photon beam diameters ranging from 12.5 to 40.0 mm for the Clinac-600C and from 5.0 to 50.0 mm for the Mevatron MD2. The parameters were evaluated by using a parallel plate ionization chamber (Markus), Kodak X-Omat V dosimetric films, thermoluminescent dosemeters (Harschaw, TLD-100) and photodiodes. The maximum tissue-ratio, the off-axis profile and the output factors were determined and the results were compared to those reported elsewhere. A study of the dosimetric characteristics of some commercially available phototransistors was also carried out. The results showed that these electronic components can be successfully used for measuring the dosimetric parameters of small diameter photon beans used in

  8. The radiobiology of prostate cancer including new aspects of fractionated radiotherapy

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    Fowler, Jack F. [Medical School of Wisconsin Univ., Madison (United States). Dept. of Human Oncology

    2005-05-01

    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

  9. Proton Radiotherapy for Pediatric Sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Ladra, Matthew M.; Yock, Torunn I., E-mail: tyock@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114 (United States)

    2014-01-14

    Pediatric sarcomas represent a distinct group of pathologies, with approximately 900 new cases per year in the United States alone. Radiotherapy plays an integral role in the local control of these tumors, which often arise adjacent to critical structures and growing organs. The physical properties of proton beam radiotherapy provide a distinct advantage over standard photon radiation by eliminating excess dose deposited beyond the target volume, thereby reducing both the dose of radiation delivered to non-target structures as well as the total radiation dose delivered to a patient. Dosimetric studies comparing proton plans to IMRT and 3D conformal radiation have demonstrated the superiority of protons in numerous pediatric malignancies and data on long-term clinical outcomes and toxicity is emerging. In this article, we review the existing clinical and dosimetric data regarding the use of proton beam radiation in malignant bone and soft tissue sarcomas.

  10. 6th Annual Conference of Indian Brachytherapy Society 2016 (IBSCON 2016) Proceedings

    OpenAIRE

    Srinivasan, Venkatesan; Kuppusamy, Thayalan; Bhalavat, Rajendra L.; ,; Prahlad H Yathiraj; Kumar, Uday P.; Sharan, Krishna; Singh, Anshul; Reddy, Anusha; Fernandes, Donald; Vidyasagar, M.S.; Kumar, Rishabh; Kala, Prachi; Mandal, Sanjeet; Vibhay, Pareek

    2016-01-01

    Purpose To report the incidence, severity, and time of onset of late toxicities in patients of endometrial adenocarcinoma (EA) treated with external beam radiotherapy (EBRT) + brachytherapy (BT), or vaginal brachytherapy (VBT) alone. Material and methods Archives of a single institution from 2008-2015 were studied. The indications for EBRT and VBT were based on standard recommendations. EBRT was planned to 50 Gy/25 fractions/5 weeks/3DCRT with 4-field ‘box’ technique on a dual energy linear a...

  11. Postmastectomy radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Shikama, Naoto; Koguchi, Masahiko; Sasaki, Shigeru; Kaneko, Tomoki; Shinoda, Atsunori; Nishikawa, Atsushi [Shinshu Univ., Matsumoto, Nagano (Japan). School of Medicine

    2000-10-01

    Since there have been few reports on postmastectomy radiotherapy having a high evidence level in Japan, the significance of postoperative radiotherapy and the irradiation techniques were reviewed based on reports from Western countries. Authors focused on the indications for postoperative irradiation, irradiation methods (irradiation sites, irradiation techniques; prosthetics, methods of irradiating the chest wall and lymph nodes, timing of irradiation), and complications, and discuss them. The factors thought to be adaptable to postmastectomy radiotherapy have been listed. Axillary lymph node metastasis and the size of the primary focus are thought to be important factors in locoregional recurrence. The chest wall and the supraclavicular lymph nodes are the usual sites of irradiation after mastectomy. The irradiation method consists of tangential irradiation of the chest wall and single-field irradiation of the supraclavicular lymph nodes, with 46-50 Gy in fractional doses of 1.8-2 Gy x 5/w is administered for 4.5-5.5 weeks. The timing of irradiation in the West is generally after chemotherapy. Adverse radiation effects include ischemic heart disease, pneumonitis, arm edema, rib fractures, and brachial plexus paralysis. The frequency of these complications is increased by the combined use of chemotherapy or surgery. The breast cancer cure rate in Japan is generally better than in the West. It remains to be determined whether the clinical data from Europe and America are applicable to the treatment of breast cancer in Japan. To address this issue, a clinical investigation should be performed in Japan with close cooperation between surgeons, physicians, pathologists, and radiotherapists. (K.H.)

  12. Design and test of a scintillation dosimeter for dosimetry measurements of high energy radiotherapy beams; Conception et realisation d'un dosimetre a scintillation adapte a la dosimetrie de faisceaux de rayonnements ionisants en faisceaux de rayonnements ionisants en radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Fontbonne, J.M

    2002-12-01

    This work describes the design and evaluation of the performances of a scintillation dosimeter developed for the dosimetry of radiation beams used in radiotherapy. The dosimeter consists in a small plastic scintillator producing light which is guided by means of a plastic optical fiber towards photodetectors. In addition to scintillation, high energy ionizing radiations produce Cerenkov light both in the scintillator and the optical fiber. Based on a wavelength analysis, we have developed a deconvolution technique to measure the scintillation light in the presence of Cerenkov light. We stress the advantages that are anticipated from plastic scintillator, in particular concerning tissue or water equivalence (mass stopping power, mass attenuation or mass energy absorption coefficients). We show that detectors based on this material have better characteristics than conventional dosimeters such as ionisation chambers or silicon detectors. The deconvolution technique is exposed, as well as the calibration procedure using an ionisation chamber. We have studied the uncertainty of our dosimeter. The electronics noise, the fiber transmission, the deconvolution technique and the calibration errors give an overall combined experimental uncertainty of about 0,5%. The absolute response of the dosimeter is studied by means of depth dose measurements. We show that absolute uncertainty with photons or electrons beams with energies ranging from 4 MeV to 25 MeV is less than {+-} 1 %. Last, at variance with other devices, our scintillation dosimeter does not need dose correction with depth. (author)

  13. Cost-effectiveness of radiotherapy during surgery compared with external radiation therapy in the treatment of women with breast cancer

    Directory of Open Access Journals (Sweden)

    Hedie Mosalanezhad

    2016-04-01

    Full Text Available Introduction: Intraoperative radiation therapy device (IORT is one of the several options for partial breast irradiation. IORT is sent to the tumor bed during surgery and can be replaced with conventional standard therapy (EBRT. The aim of this study was to evaluate the safety and effectiveness of IORT machine compared with EBRT and to determine the dominant option in terms of the cost-effectiveness. Method: This study was conducted in two phases; the first phase was a comprehensive review of the electronic databases search that was extracted after extraction and selection of the articles used in this article on effectiveness outcomes. Data collection form was completed by professionals and experts to estimate the cost of treatment, intraoperative radiotherapy and radiotherapy cost when using external radiation therapy process; direct costs were considered from the perspective of service provider and they were calculated in the second phase to determine the option of cost-effective ICER. Excel software was used for data analysis and sensitivity analysis was performed to determine the strength of the results of cost-effectiveness. Results:18 studies were selected but only 8 of them were shown to have acceptable quality. The consequences like “rate of cancer recurrence”, “seroma”, “necrosis”, “toxic”, “skin disorders and delayed wound healing” and “spread the pain” were among the consequences used in the selected articles. The total costs for each patient during a course of treatment for EBRT and IORT were estimated 1398 and $5337.5, respectively. During the analysis, cost-effectiveness of the consequences of cancer recurrence, seroma, necrosis and skin disorders and delayed wound healing ICER was calculated. And IORT was found to be the dominant supplier in all cases. Also, in terms of implications of toxicity and prevalence of pain, IORT had a lower cost and better effectiveness and consequently the result was more cost

  14. Effect of Different Geant4 Physical Models on Simulation of Radiotherapy Proton Beam%Geant4不同物理模型对放疗质子束模拟的影响

    Institute of Scientific and Technical Information of China (English)

    林辉; 谢聪; 张拥军; 熊桢宇; 吴东升; 曹瑞芬; FDS团队

    2015-01-01

    The Monte Carlo method is usually used to simulate the feature of the exter‐nal radiotherapy of proton beam to optimize the clinical therapy scenario .T he selection of a suitable physical model is very critical to ensure the correction and the efficiency of the simulation .This work studied nine Geant4 physical models ,which are often used in the simulation of radiotherapy of proton beam with energy of 60‐250 MeV .The dosage features and the microcosmic secondary yields in different materials were compared .The result show s that ,although the standard EM ,the low energy Penelope model and the low energy Livermore model can output the right dose distribution ,they can’t simulate the baryon yields .The parametrization driven model LHEP and the Quark gluon string‐pre‐compound model both can’ t simulate the complex ion transportation . Thus the above five models are not enough for the research calculation in the radiation protection and the radiation damage .The QGSP_BIC_EMY model in Geant4 hadron therapy exam‐ple is very bad for underestimating the dose ratio of Bragg peak to entrance and absolute dose .The QGSP_BERT model ,QGSP_BIC model and FTFP_BERT model are suitable for the radiotherapy proton beam with energy of 60‐250 MeV .%Monte Carlo方法常用于质子束剂量模拟以优化质子束临床治疗,合适的物理模型选择关系到M onte Carlo模拟结果的可靠性及模拟效率。本工作选取9个可用于质子模拟的Geant4物理模型,计算比较了质子束在多种介质中的剂量及次级粒子产额。结果表明:标准电磁物理模型、低能电磁Penel‐ope模型和Livermore模型虽在模拟质子整体剂量分布上可接受,但在微观上缺失重粒子生成。参数化驱动模型LHEP的模拟时间最短,但与QGSP相同,均不能产生复杂重离子。QGSP_BIC_EMY模型较其他模型明显低估Bragg峰‐入口剂量比和绝对剂量。QGSP_BERT 模型、QGSP_BIC模型和 FT FP

  15. Clinical implementation of 3D printing in the construction of patient specific bolus for electron beam radiotherapy for non-melanoma skin cancer

    NARCIS (Netherlands)

    Canters, R.A.M.; Lips, I.M.; Wendling, M.; Kusters, M.; Zeeland, M. van; Gerritsen, R.M.; Poortmans, P.; Verhoef, C.G.

    2016-01-01

    BACKGROUND AND PURPOSE: Creating an individualized tissue equivalent material build-up (i.e. bolus) for electron beam radiation therapy is complex and highly labour-intensive. We implemented a new clinical workflow in which 3D printing technology is used to create the bolus. MATERIAL AND METHODS: A

  16. Is argon plasma coagulation an effective and safe treatment option for patients with chronic radiation proctitis after high doses of radiotherapy?

    Directory of Open Access Journals (Sweden)

    Eduardo Hortelano

    Full Text Available Introduction: In severe cases refractory to medical treatment, APC appears to be the preferred alternative to control persistent rectal bleeding of patients with chronic radiation proctitis. Although successful outcomes have been demonstrated in patients previously treated with moderate doses of radiotherapy, there is reluctance towards its indication due to the concern of severe adverse events in patients treated with high doses of radiation. Objectives: The aim of this study was to assess the efficacy and toxicity of APC in the management of bleeding radiation-induced proctitis in patients treated with high doses of radiation for prostate cancer. Methods and materials: Data from 30 patients were treated with APC due to chronic radiation proctitis, were reviewed retrospectively. All cases had prostate cancer and 9 of them (30 % underwent previous radical prostatectomy. The median dose of conformal 3D External Beam Radiotherapy (EBRT delivered was 74 Gy (range 46-76. Median rectal D1cc and D2cc was 72.5 and 72.4 Gy respectively. Median rectal V70, V60 and V40 was 12, 39.5 and 80 %. Cardiovascular and digestive disease, diabetes, smoking behaviour, lowest haemoglobin and transfusion requirements were recorded. Indications for treatment with APC were anemia and persistent bleeding despite medical treatment. Argon gas flow was set at 1.8 l/min with an electrical power setting of 50 W. Results: Median age of all patients was 69.6 years. The median lowest haemoglobin level was 9.6 g/dL. Median time between completion of radiotherapy and first session of APC was 13 months. Ninety-four therapeutic sessions were performed (median 3 sessions. Median time follow-up was 14.5 months (range 2-61. Complete response with resolved rectal bleeding was achieved in 23 patients (77 %, partial response in 5 (16 % and no control in 2 (6 %. No patients required transfusion following therapy. Two patients developed long-term (> 6 weeks grade 2 rectal ulceration and

  17. TH-C-12A-07: Implementation of a Pulsed Low Dose Date Radiotherapy (PLRT) Protocol for Recurrent Cancers Using Advanced Beam Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C; Lin, M; Chen, L; Price, R [Fox Chase Cancer Center, Philadelphia, PA (United States); Li, J; Kang, S; Wang, P; Lang, J [Sichuan Provincial Cancer Hospital, Chengdu (China)

    2014-06-15

    Purpose: Recent in vitro and in vivo experimental findings provided strong evidence that pulsed low-dose-rate radiotherapy (PLDR) produced equivalent tumor control as conventional radiotherapy with significantly reduced normal tissue toxicities. This work aimed to implement a PLDR clinical protocol for the management of recurrent cancers utilizing IMRT and VMAT. Methods: Our PLDR protocol requires that the daily 2Gy dose be delivered in 0.2Gy×10 pulses with a 3min interval between the pulses. To take advantage of low-dose hyper-radiosensitivity the mean dose to the target is set at 0.2Gy and the maximum dose is limited to 0.4Gy per pulse. Practical planning strategies were developed for IMRT and VMAT: (1) set 10 ports for IMRT and 10 arcs for VMAT with each angle/arc as a pulse; (2) set the mean dose (0.2Gy) and maximum dose (0.4Gy) to the target per pulse as hard constraints (no constraints to OARs); (3) select optimal port/arc angles to avoid OARs; and (4) use reference structures in or around target/OARs to reduce maximum dose to the target/OARs. IMRT, VMAT and 3DCRT plans were generated for 60 H and N, breast, lung, pancreas and prostate patients and compared. Results: All PLDR treatment plans using IMRT and VMAT met the dosimetry requirements of the PLDR protocol (mean target dose: 0.20Gy±0.01Gy; maximum target dose < 0.4Gy). In comparison with 3DCRT, IMRT and VMAT exhibited improved target dose conformity and OAR dose sparing. A single arc can minimize the difference in the target dose due to multi-angle incidence although the delivery time is longer than 3DCRT and IMRT. Conclusion: IMRT and VMAT are better modalities for PLDR treatment of recurrent cancers with superior target dose conformity and critical structure sparing. The planning strategies/guidelines developed in this work are practical for IMRT/VMAT treatment planning to meet the dosimetry requirements of the PLDR protocol.

  18. Technical and dosimetric description of a hard-docking applicator system for intraoperative radiotherapy with electron beams in a non-dedicated accelerator; Descripcion tecnica y dosimetrica de un sistema aplicador de alineacion rigida para radioterapia intraoperatoria con haces de electrones en acelerador convencional

    Energy Technology Data Exchange (ETDEWEB)

    Sendon del Rio, J. R.; Ayala Lazaro, R.; Jimenez Rojas, R.; Gomez Cores, S.; Gonzalez Ruiz, C.; Garcia Hernandez, M. J.; Lopez Bote, M. A.

    2013-07-01

    Our experience with a hard-docking applicator system for intraoperative electron-beam radiotherapy is described. In the introduction, we review the configuration options of the applicator systems. In the following section, the applicator system us ed and the methods of measurement are described. The dosimetric characterization, some problems related to the system and the solutions we adopted are shown in results. Finally, the dosimetric behavior is discussed developing a consistent theoretical explanation. (Author)

  19. Self-assessed bowel toxicity after external beam radiotherapy for prostate cancer - predictive factors on irritative symptoms, incontinence and rectal bleeding

    Directory of Open Access Journals (Sweden)

    Klotz Jens

    2009-09-01

    Full Text Available Abstract Background The aim of the study was to evaluate self-assessed bowel toxicity after radiotherapy (RT for prostate cancer. In contrast to rectal bleeding, information concerning irritative symptoms (rectal urgency, pain and incontinence after RT has not been adequately documented and reported in the past. Methods Patients (n = 286 have been surveyed prospectively before (A, at the last day (70.2-72.0 Gy; B, a median time of two (C and 16 months after RT (D using a validated questionnaire (Expanded Prostate Cancer Index Composite. Bowel domain score changes were analyzed and patient-/dose-volume-related factors tested for a predictive value on three separate factors (subscales: irritative symptoms, incontinence and rectal bleeding. Results Irritative symptoms were most strongly affected in the acute phase, but the scores of all subscales remained slightly lower at time D in comparison to baseline scores. Good correlations (correlation indices >0.4; p Conclusion PTV and specific comorbidities are important predictive factors on adverse bowel quality of life changes after RT for prostate cancer. However, greater rectum volumes inside high isodose levels have not been found to be associated with lower quality of life scores.

  20. Clinical evaluation of X-ray voxel Monte Carlo versus pencil beam-based dose calculation in stereotactic body radiotherapy of lung cancer under normal and deep inspiration breath hold.

    Science.gov (United States)

    Landoni, V; Borzì, G R; Strolin, S; Bruzzaniti, V; Soriani, A; D'Alessio, D; Ambesi, F; Di Grazia, A M; Strigari, L

    2015-06-01

    The purpose of this study is to evaluate the differences between dose distributions calculated with the pencil beam (PB) and X-ray voxel Monte Carlo (MC) algorithms for patients with lung cancer using intensity-modulated radiotherapy (IMRT) or HybridArc techniques. The 2 algorithms were compared in terms of dose-volume histograms, under normal and deep inspiration breath hold, and in terms of the tumor control probability (TCP). The dependence of the differences in tumor volume and location was investigated. Dosimetric validation was performed using Gafchromic EBT3 (International Specialty Products, ISP, Wayne, NJ). Forty-five Computed Tomography (CT) data sets were used for this study; 40 Gy at 8 Gy/fraction was prescribed with 5 noncoplanar 6-MV IMRT beams or 3 to 4 dynamic conformal arcs with 3 to 5 IMRT beams distributed per arc. The plans were first calculated with PB and then recalculated with MC. The difference between the mean tumor doses was approximately 10% ± 4%; these differences were even larger under deep inspiration breath hold. Differences between the mean tumor dose correlated with tumor volume and path length of the beams. The TCP values changed from 99.87% ± 0.24% to 96.78% ± 4.81% for both PB- and MC-calculated plans (P = .009). When a fraction of hypoxic cells was considered, the mean TCP values changed from 76.01% ± 5.83% to 34.78% ± 18.06% for the differently calculated plans (P < .0001). When the plans were renormalized to the same mean dose at the tumor, the mean TCP for oxic cells was 99.05% ± 1.59% and for hypoxic cells was 60.20% ± 9.53%. This study confirms that the MC algorithm adequately accounts for inhomogeneities. The inclusion of the MC in the process of IMRT optimization could represent a further step in the complex problem of determining the optimal treatment plan.

  1. 利用锥形束CT分析宫颈癌调强适形放疗摆位误差%Setup Errors Analysis with Cone Beam CT for Uterine Cervix Cancer Treated by Intensity Modulated Radiotherapy

    Institute of Scientific and Technical Information of China (English)

    陈鑑; 郭和锋; 林浩; 王国喜

    2013-01-01

    目的:利用锥形束CT(Cone-Beam Computed Tomography,CBCT)影像技术研究本院宫颈癌调强放射治疗(Intensity Modulated Radiation Therapy,IMRT)中的摆位误差,并计算出计划靶区(Planning Target Volume,PTV)的外扩边界范围。方法应用瓦里安TrueBeam放射治疗系统治疗宫颈癌64例,CBCT扫描1次/w,将CBCT图像和原计划CT图像进行匹配得出X、Y、Z轴方向的线性摆位误差,分析误差及其分布规律,推算出 CTV(Clinical Target Volume,CTV)到 PTV的外放边界值。结果得出在X、Y、Z轴方向上的系统误差±随机误差分别为(2.13±1.70)、(2.39±1.99)、(2.50±1.89)mm,推算出本院宫颈癌出 X,Y,Z轴 CTV到 PTV的Margin分别为6.5mm,7.4mm,7.6mm。结论通过CBCT测量摆位误差并进行调整可提高患者摆位精度,为外扩 CTV边界提供了理论依据,使治疗计划的实施更精确。%Objective:The purpose of his work was to invest the setup errors in Intensity modulated radiotherapy for uterine cervix cancer by cone-beam CT (Cone Beam Computerized Tomography, CBCT)imaging technology, and to calculate the safety margins of planning target volume (PTV). Methods:64 patients were treated with Varian TrueBeam system.Al patients had received CBCT once a week.The acquired CBCT images were compared with planning CT images. The errors on X,Y,Z axes were analyzed and the PTV margin was calculated. Results:The average setup error (∑±σ)in X-axis, Y-axis, and Z-axis directions were (2.13±1.70)mm,( 2.39±1.99)mm, (2.50 ±1.89)mm, and the margin of PTV of uterine cervix cancer in three directions (X,Y,Z)was 6.5mm,7.4mm,7.6mm respectively. Conclusions:Measurement of setup error delivery using CBCT scan combined with on-line correction could improve the patient setup precision and may make our design of radiotherapy system more scientific and normal.

  2. Sci—Sat AM: Stereo — 08: Stereotactic Ablative Radiotherapy (SABR) for low, intermediate and high risk prostate cancer using Volumetric Modulated Arc Therapy (VMAT) with a 10x Flattening Filter Free (FFF) beam

    Energy Technology Data Exchange (ETDEWEB)

    Mestrovic, A; Fortin, D; Alexander, A [BC Cancer Agency - Vancouver Island Centre (Canada)

    2014-08-15

    Purpose: To determine the feasibility of using Volumetric Modulated Arc Therapy (VMAT) with a 10x Flattening Filter Free (FFF) beam for Stereotactic Ablative Radiotherapy (SABR) for low, intermediate and high risk prostate cancer. Methods and Materials: Ten anonymized patient CT data sets were used in this planning study. For each patient CT data set, three sets of contours were generated: 1) low risk, 2) intermediate risk, and 3) high risk scenarios. For each scenario, a single-arc and a double-arc VMAT treatment plans were created. Plans were generated with the Varian Eclipse™ treatment planning system for a Varian TrueBeam™ linac equipped with Millenium 120 MLC. Plans were created using a 10x-FFF beam with a maximum dose rate of 2400 MU/min. Dose prescription was 36.25Gy/5 fractions with the planning objective of covering 99% of the Planning Target Volume with the 95% of the prescription dose. Normal tissue constraints were based on provincial prostate SABR planning guidelines, derived from national and international prostate SABR protocols. Plans were evaluated and compared in terms of: 1) dosimetric plan quality, and 2) treatment delivery efficiency. Results: Both single-arc and double-arc VMAT plans were able to meet the planning goals for low, intermediate and high risk scenarios. No significant dosimetric differences were observed between the plans. However, the treatment time was significantly lower for a single-arc VMAT plans. Conclusions: Prostate SABR treatments are feasible with 10x-FFF VMAT technique. A single-arc VMAT offers equivalent dosimetric plan quality and a superior treatment delivery efficiency, compared to a double-arc VMAT.

  3. Verification of dose distributions of intensity-modulated radiotherapy beams using a portal imaging device; Caracterizacion de un sistema de imagen portal basado en silicio amorfo para la medida de distribuciones de dosis absorbida

    Energy Technology Data Exchange (ETDEWEB)

    Perez Moreno, J. M.; Fernandez Leton, J. P.; Zucca Aparicio, D.; Garcia Ruiz-Zorrila, J.; Minambres Moro, A.

    2011-07-01

    We have developed a method for using a portal imaging device based on amorphous silicon (EPID) for the dosimetric verification of intensity modulated radiotherapy (IMRT) treatments using 6 MV beams. The images obtained using the imaging system are de convolved with a kernel for radiation and scattering of light generated in the EPID. This kernel has an analytical form and has been experimentally determined. The fluence thus obtained is convolved with a dose deposition kernel, also modeled analytically in a empirical way. The result is an absorbed dose distribution in water at 5 cm depth. The difference between the measured dose using portal imaging device and ionization chamber is -0.3 {+-} 0.9 % in open fields, with a maximum deviation of 1.5% in a 20 cm X 20 cm field with 60 degree centigrade virtual wedge. The degree of agreement between dose distributions measured with the EPID and ionization chamber array is satisfactory, exceeding all cases evaluated 95% of points with {gamma} < 1 using 3%, 3 mm criteria for gamma analysis. (Author) 25 refs.

  4. Towards online MRI-guided radiotherapy

    NARCIS (Netherlands)

    Bol, G.H.

    2015-01-01

    First, we present two offline position verification methods which can be used in radiotherapy for detecting the position of the bony anatomy of a patient automatically with portal imaging, even if every single portal image of each segment of an (IMRT) treatment beam contains insufficient matching in

  5. Effectiveness of respiratory-gated radiotherapy with audio-visual biofeedback for synchrotron-based scanned heavy-ion beam delivery

    Science.gov (United States)

    He, Pengbo; Li, Qiang; Zhao, Ting; Liu, Xinguo; Dai, Zhongying; Ma, Yuanyuan

    2016-12-01

    A synchrotron-based heavy-ion accelerator operates in pulse mode at a low repetition rate that is comparable to a patient’s breathing rate. To overcome inefficiencies and interplay effects between the residual motion of the target and the scanned heavy-ion beam delivery process for conventional free breathing (FB)-based gating therapy, a novel respiratory guidance method was developed to help patients synchronize their breathing patterns with the synchrotron excitation patterns by performing short breath holds with the aid of personalized audio-visual biofeedback (BFB) system. The purpose of this study was to evaluate the treatment precision, efficiency and reproducibility of the respiratory guidance method in scanned heavy-ion beam delivery mode. Using 96 breathing traces from eight healthy volunteers who were asked to breathe freely and guided to perform short breath holds with the aid of BFB, a series of dedicated four-dimensional dose calculations (4DDC) were performed on a geometric model which was developed assuming a linear relationship between external surrogate and internal tumor motions. The outcome of the 4DDCs was quantified in terms of the treatment time, dose-volume histograms (DVH) and dose homogeneity index. Our results show that with the respiratory guidance method the treatment efficiency increased by a factor of 2.23-3.94 compared with FB gating, depending on the duty cycle settings. The magnitude of dose inhomogeneity for the respiratory guidance methods was 7.5 times less than that of the non-gated irradiation, and good reproducibility of breathing guidance among different fractions was achieved. Thus, our study indicates that the respiratory guidance method not only improved the overall treatment efficiency of respiratory-gated scanned heavy-ion beam delivery, but also had the advantages of lower dose uncertainty and better reproducibility among fractions.

  6. SU-E-J-39: Comparison of PTV Margins Determined by In-Room Stereoscopic Image Guidance and by On-Board Cone Beam Computed Tomography Technique for Brain Radiotherapy Patients

    Energy Technology Data Exchange (ETDEWEB)

    Ganesh, T; Paul, S; Munshi, A; Sarkar, B; Krishnankutty, S; Sathya, J; George, S; Jassal, K; Roy, S; Mohanti, B [Fortis Memorial Research Institute, Gurgaon (India)

    2014-06-01

    Purpose: Stereoscopic in room kV image guidance is a faster tool in daily monitoring of patient positioning. Our centre, for the first time in the world, has integrated such a solution from BrainLAB (ExacTrac) with Elekta's volumetric cone beam computed tomography (XVI). Using van Herk's formula, we compared the planning target volume (PTV) margins calculated by both these systems for patients treated with brain radiotherapy. Methods: For a total of 24 patients who received partial or whole brain radiotherapy, verification images were acquired for 524 treatment sessions by XVI and for 334 sessions by ExacTrac out of the total 547 sessions. Systematic and random errors were calculated in cranio-caudal, lateral and antero-posterior directions for both techniques. PTV margins were then determined using van Herk formula. Results: In the cranio-caudal direction, systematic error, random error and the calculated PTV margin were found to be 0.13 cm, 0.12 cm and 0.41 cm with XVI and 0.14 cm, 0.13 cm and 0.44 cm with ExacTrac. The corresponding values in lateral direction were 0.13 cm 0.1 cm and 0.4 cm with XVI and 0.13 cm, 0.12 cm and 0.42 cm with ExacTrac imaging. The same parameters for antero-posterior were for 0.1 cm, 0.11 cm and 0.34 cm with XVI and 0.13 cm, 0.16 cm and 0.43 cm with ExacTrac imaging. The margins estimated with the two imaging modalities were comparable within ± 1 mm limit. Conclusion: Verification of setup errors in the major axes by two independent imaging systems showed the results are comparable and within ± 1 mm. This implies that planar imaging based ExacTrac can yield equal accuracy in setup error determination as the time consuming volumetric imaging which is considered as the gold standard. Accordingly PTV margins estimated by this faster imaging technique can be confidently used in clinical setup.

  7. Radiotherapy for Hodgkin lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Lena [Rigshospitalet Copenhagen Univ. (Denmark). Depts. of Oncology and Haematology; Yahalom, Joachim (eds.) [Memorial Sloan-Kettering Cancer, New York, NY (United States). Dept. of Radiation Oncology

    2011-07-01

    This book deals in detail with all aspects of the best practice in modern radiotherapy for Hodgkin lymphoma. It provides the background and rationale for the inclusion of radiotherapy in today's combined-modality approach, including special clinical situations such as Hodgkin lymphoma in children, in the pregnant patient, and in the elderly. Radiotherapy planning using state-of-the-art imaging, target definition, planning software, and treatment equipment is expounded in detail. Acute and long-term side effects of radiotherapy are analyzed, and the implications for modern radiotherapy approaches in Hodgkin lymphomas are explained. (orig.)

  8. Development and implementation in the Monte Carlo code PENELOPE of a new virtual source model for radiotherapy photon beams and portal image calculation

    Science.gov (United States)

    Chabert, I.; Barat, E.; Dautremer, T.; Montagu, T.; Agelou, M.; Croc de Suray, A.; Garcia-Hernandez, J. C.; Gempp, S.; Benkreira, M.; de Carlan, L.; Lazaro, D.

    2016-07-01

    This work aims at developing a generic virtual source model (VSM) preserving all existing correlations between variables stored in a Monte Carlo pre-computed phase space (PS) file, for dose calculation and high-resolution portal image prediction. The reference PS file was calculated using the PENELOPE code, after the flattening filter (FF) of an Elekta Synergy 6 MV photon beam. Each particle was represented in a mobile coordinate system by its radial position (r s ) in the PS plane, its energy (E), and its polar and azimuthal angles (φ d and θ d ), describing the particle deviation compared to its initial direction after bremsstrahlung, and the deviation orientation. Three sub-sources were created by sorting out particles according to their last interaction location (target, primary collimator or FF). For each sub-source, 4D correlated-histograms were built by storing E, r s , φ d and θ d values. Five different adaptive binning schemes were studied to construct 4D histograms of the VSMs, to ensure histogram efficient handling as well as an accurate reproduction of E, r s , φ d and θ d distribution details. The five resulting VSMs were then implemented in PENELOPE. Their accuracy was first assessed in the PS plane, by comparing E, r s , φ d and θ d distributions with those obtained from the reference PS file. Second, dose distributions computed in water, using the VSMs and the reference PS file located below the FF, and also after collimation in both water and heterogeneous phantom, were compared using a 1.5%-0 mm and a 2%-0 mm global gamma index, respectively. Finally, portal images were calculated without and with phantoms in the beam. The model was then evaluated using a 1%-0 mm global gamma index. Performance of a mono-source VSM was also investigated and led, as with the multi-source model, to excellent results when combined with an adaptive binning scheme.

  9. Development and implementation in the Monte Carlo code PENELOPE of a new virtual source model for radiotherapy photon beams and portal image calculation.

    Science.gov (United States)

    Chabert, I; Barat, E; Dautremer, T; Montagu, T; Agelou, M; Croc de Suray, A; Garcia-Hernandez, J C; Gempp, S; Benkreira, M; de Carlan, L; Lazaro, D

    2016-07-21

    This work aims at developing a generic virtual source model (VSM) preserving all existing correlations between variables stored in a Monte Carlo pre-computed phase space (PS) file, for dose calculation and high-resolution portal image prediction. The reference PS file was calculated using the PENELOPE code, after the flattening filter (FF) of an Elekta Synergy 6 MV photon beam. Each particle was represented in a mobile coordinate system by its radial position (r s ) in the PS plane, its energy (E), and its polar and azimuthal angles (φ d and θ d ), describing the particle deviation compared to its initial direction after bremsstrahlung, and the deviation orientation. Three sub-sources were created by sorting out particles according to their last interaction location (target, primary collimator or FF). For each sub-source, 4D correlated-histograms were built by storing E, r s , φ d and θ d values. Five different adaptive binning schemes were studied to construct 4D histograms of the VSMs, to ensure histogram efficient handling as well as an accurate reproduction of E, r s , φ d and θ d distribution details. The five resulting VSMs were then implemented in PENELOPE. Their accuracy was first assessed in the PS plane, by comparing E, r s , φ d and θ d distributions with those obtained from the reference PS file. Second, dose distributions computed in water, using the VSMs and the reference PS file located below the FF, and also after collimation in both water and heterogeneous phantom, were compared using a 1.5%-0 mm and a 2%-0 mm global gamma index, respectively. Finally, portal images were calculated without and with phantoms in the beam. The model was then evaluated using a 1%-0 mm global gamma index. Performance of a mono-source VSM was also investigated and led, as with the multi-source model, to excellent results when combined with an adaptive binning scheme.

  10. Influence of the delta ray production threshold on water-to-air stopping power ratio calculations for carbon ion beam radiotherapy.

    Science.gov (United States)

    Sánchez-Parcerisa, D; Gemmel, A; Jäkel, O; Rietzel, E; Parodi, K

    2013-01-07

    Previous calculations of the water-to-air stopping power ratio (s(w,)(air)) for carbon ion beams did not involve tracking of delta ray electrons, even though previous calculations with protons predict an effect up to 1%. We investigate the effect of the delta ray production threshold in s(w,)(air) calculations and propose an empirical expression which takes into account the effect of the delta ray threshold as well as the uncertainty in the mean ionization potentials (I-values) of air and water. The formula is derived from the results of Monte Carlo calculations using the most up-to-date experimental data for I-values and a delta ray production threshold of 10 keV. It allows us to reduce the standard uncertainty in s(w,)(air) below 0.8%, instead of the current 2% given in international protocols, which results in a reduction of the overall uncertainty for absolute dosimetry based on air-filled ionization chambers.

  11. Discussion of Cone-beam CT-guided Radiotherapy for Breast Cancer%锥形束CT引导乳腺癌放射治疗的探讨

    Institute of Scientific and Technical Information of China (English)

    叶森林; 梁廷; 荣青碧

    2010-01-01

    目的:探讨锥形束CT(Cone-Beam CT,CBCT)在乳腺癌三维适形或调强放射治疗位置精度保证中的应用.方法:采用Varian-21EX直线加速器机载影像系统(OBI),在适形或调强放射治疗前行锥形束CT扫描,系统自动重建成断层图像,获得患者三维方向的摆位数据,直接与治疗计划CT扫描图像相匹配后得出两者间的误差数据,对误差予以校正后行精确治疗.结果:经锥形束CT扫描并校正后,左右、腹背和头脚方向的位置误差值分别由(1.7±3.25)mm、(0.9±1.27)mm、(2.1±4.31)mm下降至(0.6±1.38)mm、(0.2±0.72)mm、(0.8±1.65)mm.结论:CBCT对于乳腺癌适形或调强放射治疗的精确实施具有重要作用.

  12. Dosimetric accuracy assessment of a treatment plan verification system for scanned proton beam radiotherapy: one-year experimental results and Monte Carlo analysis of the involved uncertainties

    Science.gov (United States)

    Molinelli, S.; Mairani, A.; Mirandola, A.; Vilches Freixas, G.; Tessonnier, T.; Giordanengo, S.; Parodi, K.; Ciocca, M.; Orecchia, R.

    2013-06-01

    During one year of clinical activity at the Italian National Center for Oncological Hadron Therapy 31 patients were treated with actively scanned proton beams. Results of patient-specific quality assurance procedures are presented here which assess the accuracy of a three-dimensional dose verification technique with the simultaneous use of multiple small-volume ionization chambers. To investigate critical cases of major deviations between treatment planning system (TPS) calculated and measured data points, a Monte Carlo (MC) simulation tool was implemented for plan verification in water. Starting from MC results, the impact of dose calculation, dose delivery and measurement set-up uncertainties on plan verification results was analyzed. All resulting patient-specific quality checks were within the acceptance threshold, which was set at 5% for both mean deviation between measured and calculated doses and standard deviation. The mean deviation between TPS dose calculation and measurement was less than ±3% in 86% of the cases. When all three sources of uncertainty were accounted for, simulated data sets showed a high level of agreement, with mean and maximum absolute deviation lower than 2.5% and 5%, respectively.

  13. SU-E-T-59: A Novel Multi-Beam Dynamic IMRT with Fixed-Jaw Technique for Left Breast Cancer Patients with Regional Lymph Nodes Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J; Yang, Z; Hu, W [Fudan University Shanghai Cancer Center, Shanghai (China)

    2015-06-15

    Purpose: This study was to investigate the dosimetric benefit of a novel intensity modulated radiation therapy (IMRT) technique for irradiating the left breast and regional lymph node (RLN). Methods: The breast and RLN (internal mammary node and periclavicular node) and normal tissue were contoured for 16 consecutive left-sided breast cancer patients previously treated with RT after lumpectomy. Nine equi-spaced fields IMRT (9 -field IMRT), tangential multi-beam IMRT (tangential-IMRT) and IMRT with fixed-jaw technique (FJT-IMRT) were developed and compared with three-dimensional conformal RT (3DCRT). Prescribed dose was 50 Gy in 25 fractions. Dose distributions and dose volume histograms were used to evaluate plans. Results: All IMRTs achieved similar target coverage and substantially reduced heart V30 and V20 compared to the 3DCRT. The average heart mean dose had different changes, which were 9.0Gy for 9-field IMRT, 5.7Gy for tangential-IMRT and 4.2Gy for FJT-IMRT. For the contralateral lung and breast, the 9-field IMRT has the highest mean dose; and the FJT-IMRT and tangential-IMRT had similar lower value. For the thyroid, both 9-field IMRT and FJT-IMRT had similar V30 (20% and 22%) and were significantly lower than that of 3DCRT (34%) and tangential-IMRT (46%). Moreover, the thyroid mean dose of FJT-IMRT is the lowest. For cervical esophagus and humeral head, the FJT-IMRT also had the best sparing. Conclusion: All 9-field IMRT, tangential-IMRT and FJT-IMRT had superiority for targets coverage and substantially reduced the heart volume of high dose irradiation. The FJT-IMRT showed advantages of avoiding the contralateral breast and lung irradiation and decreasing the thyroid, humeral head and cervical esophagus radiation dose at the expense of a slight monitor units (MUs) increasing.

  14. A study on a dental device for the prevention of mucosal dose enhancement caused by backscatter radiation from dental alloy during external beam radiotherapy.

    Science.gov (United States)

    Katsura, Kouji; Utsunomiya, Satoru; Abe, Eisuke; Sakai, Hironori; Kushima, Naotaka; Tanabe, Satoshi; Yamada, Takumi; Hayakawa, Takahide; Yamanoi, Yoshihiko; Kimura, Syuhei; Wada, Shinichi; Aoyama, Hidefumi; Hayashi, Takafumi

    2016-11-01

    The changes in dose distribution caused by backscatter radiation from a common commercial dental alloy (Au-Ag-Pd dental alloy; DA) were investigated to identify the optimal material and thicknesses of a dental device (DD) for effective prevention of mucositis. To this end, 1 cm(3) of DA was irradiated with a 6-MV X-ray beam (100 MU) in a field size of 10 × 10 cm(2) using a Novalis TX linear accelerator. Ethylene vinyl acetate copolymer, polyolefin elastomer, and polyethylene terephthalate (PET) were selected as DD materials. The depth dose along the central axis was determined with respect to the presence/absence of DA and DDs at thicknesses of 1-10 mm using a parallel-plate ionization chamber. The dose in the absence of DDs showed the lowest value at a distance of 5 mm from the DA surface and gradually increased with distance between the measurement point and the DA surface for distances of ≥5 mm. Except for PET, no significant difference between the DA dose curves for the presence and absence of DDs was observed. In the dose curve, PET showed a slightly higher dose for DA with DD than for DA without DD for thicknesses of ≥4 mm. The findings herein suggest that the optimal DD material for preventing local dose enhancement of the mucosa caused by DA backscatter radiation should have a relatively low atomic number and physical density and that optimal DD thickness should be chosen considering backscatter radiation and percentage depth dose.

  15. Comparison of pencil-beam, collapsed-cone and Monte-Carlo algorithms in radiotherapy treatment planning for 6-MV photons

    Science.gov (United States)

    Kim, Sung Jin; Kim, Sung Kyu; Kim, Dong Ho

    2015-07-01

    Treatment planning system calculations in inhomogeneous regions may present significant inaccuracies due to loss of electronic equilibrium. In this study, three different dose calculation algorithms, pencil beam (PB), collapsed cone (CC), and Monte-Carlo (MC), provided by our planning system were compared to assess their impact on the three-dimensional planning of lung and breast cases. A total of five breast and five lung cases were calculated by using the PB, CC, and MC algorithms. Planning treatment volume (PTV) and organs at risk (OARs) delineations were performed according to our institution's protocols on the Oncentra MasterPlan image registration module, on 0.3-0.5 cm computed tomography (CT) slices taken under normal respiration conditions. Intensitymodulated radiation therapy (IMRT) plans were calculated for the three algorithm for each patient. The plans were conducted on the Oncentra MasterPlan (PB and CC) and CMS Monaco (MC) treatment planning systems for 6 MV. The plans were compared in terms of the dose distribution in target, the OAR volumes, and the monitor units (MUs). Furthermore, absolute dosimetry was measured using a three-dimensional diode array detector (ArcCHECK) to evaluate the dose differences in a homogeneous phantom. Comparing the dose distributions planned by using the PB, CC, and MC algorithms, the PB algorithm provided adequate coverage of the PTV. The MUs calculated using the PB algorithm were less than those calculated by using. The MC algorithm showed the highest accuracy in terms of the absolute dosimetry. Differences were found when comparing the calculation algorithms. The PB algorithm estimated higher doses for the target than the CC and the MC algorithms. The PB algorithm actually overestimated the dose compared with those calculated by using the CC and the MC algorithms. The MC algorithm showed better accuracy than the other algorithms.

  16. Dosimetric Study of Current Treatment Options for Radiotherapy in Retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Eldebawy, Eman [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Department of Radiation Oncology, Children' s Cancer Hospital, Cairo (Egypt); Parker, William, E-mail: william.parker@mcgill.ca [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Abdel Rahman, Wamied [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Freeman, Carolyn R. [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada)

    2012-03-01

    Purpose: To determine the best treatment technique for patients with retinoblastoma requiring radiotherapy to the whole eye. Methods and Materials: Treatment plans for 3 patients with retinoblastoma were developed using 10 radiotherapy techniques including electron beams, photon beam wedge pair (WP), photon beam three-dimensional conformal radiotherapy (3D-CRT), fixed gantry intensity-modulated radiotherapy (IMRT), photon volumetric arc therapy (VMAT), fractionated stereotactic radiotherapy, and helical tomotherapy (HT). Dose-volume analyses were carried out for each technique. Results: All techniques provided similar target coverage; conformity was highest for VMAT, nine-field (9F) IMRT, and HT (conformity index [CI] = 1.3) and lowest for the WP and two electron techniques (CI = 1.8). The electron techniques had the highest planning target volume dose gradient (131% of maximum dose received [D{sub max}]), and the CRT techniques had the lowest (103% D{sub max}) gradient. The volume receiving at least 20 Gy (V{sub 20Gy}) for the ipsilateral bony orbit was lowest for the VMAT and HT techniques (56%) and highest for the CRT techniques (90%). Generally, the electron beam techniques were superior in terms of brain sparing and delivered approximately one-third of the integral dose of the photon techniques. Conclusions: Inverse planned image-guided radiotherapy delivered using HT or VMAT gives better conformity index, improved orbital bone and brain sparing, and a lower integral dose than other techniques.

  17. Track structure modelling for ion radiotherapy

    CERN Document Server

    Korcyl, Marta

    2014-01-01

    In its broadest terms, doctoral dissertation entitled "Track structure modelling for ion radiotherapy" is part of the supporting research background in the development of the ambitious proton radiotherapy project currently under way at the Institute of Nuclear Physics PAN in Krak\\'ow. Another broad motivation was the desire to become directly involved in research on a topical and challenging subject of possibly developing a therapy planning system for carbon beam radiotherapy, based in its radiobiological part on the Track Structure model developed by prof. Robert Katz over 50 years ago. Thus, the general aim of this work was, firstly, to recapitulate the Track Structure model and to propose an updated and complete formulation of this model by incorporating advances made by several authors who had contributed to its development in the past. Secondly, the updated and amended (if necessary) formulation of the model was presented in a form applicable for use in computer codes which would constitute the "radiobio...

  18. 3D dosimetry in patients with early breast cancer undergoing Intraoperative Avidination for Radionuclide Therapy (IART {sup registered}) combined with external beam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, Mahila E.; Cremonesi, Marta; Di Dia, Amalia; Botta, Francesca; Pedroli, Guido [European Institute of Oncology, Division of Medical Physics, Milan (Italy); De Cicco, Concetta; Calabrese, Michele; Paganelli, Giovanni [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Sarnelli, Anna [IRCCS Istituto Romagnolo per lo Studio e la Cura dei Tumori, Medical Physics Unit, Meldola, FC (Italy); Pedicini, Piernicola [Centro Regionale Oncologico Basilicata (IRCCS-CROB), Department of Radiation Oncology, Rionero in Vulture, PZ (Italy); Orecchia, Roberto [European Institute of Oncology, Division of Radiotherapy, Milan (Italy)

    2012-11-15

    Intraoperative Avidination for Radionuclide Therapy (IART {sup registered}) is a novel targeted radionuclide therapy recently used in patients with early breast cancer. It is a radionuclide approach with {sup 90}Y-biotin combined with external beam radiotherapy (EBRT) to release a boost of radiation in the tumour bed. Two previous clinical trials using dosimetry based on the calculation of mean absorbed dose values with the hypothesis of uniform activity distribution (MIRD 16 method) assessed the feasibility and safety of IART {sup registered}. In the present retrospective study, a voxel dosimetry analysis was performed to investigate heterogeneity in distribution of the absorbed dose. The aim of this work was to compare dosimetric and radiobiological evaluations derived from average absorbed dose vs. voxel absorbed dose approaches. We evaluated 14 patients who were injected with avidin into the tumour bed after conservative surgery and 1 day later received an intravenous injection of 3.7 GBq of {sup 90}Y-biotin (together with 185 MBq {sup 111}In-biotin for imaging). Sequential images were used to estimate the absorbed dose in the target region according to the standard dosimetry method (SDM) and the voxel dosimetry method (VDM). The biologically effective dose (BED) distribution was also evaluated. Dose/volume and BED volume histograms were generated to derive equivalent uniform BED (EUBED) and equivalent uniform dose (EUD) values. No ''cold spots'' were highlighted by voxel dosimetry. The median absorbed-dose in the target region was 20 Gy (range 15-27 Gy) by SDM, and the median EUD was 20.4 Gy (range 16.5-29.4 Gy) by the VDM; SDM and VDM estimates differed by about 6 %. The EUD/mean voxel absorbed dose ratio was >0.9 in all patients, indicative of acceptable uniformity in the target. The median BED and EUBED values were 21.8 Gy (range 15.9-29.3 Gy) and 22.8 Gy (range 17.3-31.8 Gy), respectively. VDM highlighted the absence of significant

  19. Application of individual lead shield in radiotherapy of eyelid tumor

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, Tadashi; Taniguchi, Hisashi; Inoue, Takaaki; Ohyama, Takashi [Tokyo Medical and Dental Univ. (Japan). Hospital; Oki, Meiko; Takeda, Masamune; Shibuya, Hitoshi

    1999-06-01

    In the treatment of the maxillofacial tumors, radiotherapy plays an important role in the achievement of good local control and to keep the normal shape and function. For the tumors occurring in or adjacent to the orbit, especially the tumors of eyelids, radiotherapy combined with/without surgery also yields better results than surgery alone, but the lens of the eye is a radiosensitive organ. Loss of vision could occur when radiation beam is directed at the eye, so radiotherapy prostheses must be used in the radiotherapy of eyelid tumor. An individual lead shield for the lens of eye was made for each of the 10 eyelid tumor patients and it was carefully placed in the conjunctival sac after anaesthesia with a few drops of oxybuprocaine (Benoxil) to avoid irradiation of the globe. The lead shield was applied to protect the normal surrounding structures. Excellent cosmetic and functional results were achieved during and after radiotherapy. (author)

  20. A systematic review of antiproton radiotherapy

    Directory of Open Access Journals (Sweden)

    Martin-Immanuel eBittner

    2014-01-01

    Full Text Available Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  1. Sorafenib and radiotherapy association for hepatocellular carcinoma; Sorafenib et radiotherapie dans le carcinome hepatocellulaire

    Energy Technology Data Exchange (ETDEWEB)

    Girard, N. [Service de pneumologie, hopital Louis-Pradel, hospices Civils de Lyon, 28, avenue du Doyen-Jean-Lepine, 69500 Bron (France); UMR 754, universite Claude-Bernard Lyon 1, 43, boulevard du 11-novembre-1918, 69622 Villeurbanne cedex (France); Mornex, F. [UMR 754, universite Claude-Bernard Lyon 1, 43, boulevard du 11-novembre-1918, 69622 Villeurbanne cedex (France); Departement de radiotherapie-oncologie, centre hospitalier Lyon Sud, 165, chemin du Grand-Revoyet, 69495 Pierre-Benite cedex (France)

    2011-02-15

    Conformal radiotherapy is a promising therapeutic strategy for hepatocellular carcinoma (HCC), producing local control rates above 90% within the radiation beam. However, survival after radiotherapy remains limited by the high frequency of intra- and extra-hepatic recurrences, which occurs in 40-50 and 20-30% of cases, respectively. Sorafenib (BAY43-9006, Nexavar; Bayer, West Haven, CT) is a small molecule inhibitor that demonstrated potent activity to target v-raf murine sarcoma oncogene homologue B1 (BRAF) and VEGFR tyrosine kinases. Sorafenib is the only drug that demonstrated effectiveness to increase overall survival in advanced or metastatic hepatocellular carcinoma. The rationale to combine radiotherapy with sorafenib is the following: (1) targeting RAS-RAF-MAPK and VEGFR signaling pathways, which are specifically activated after exposure to radiation, and responsible for radio-resistance phenomenon; (2) enhancing the oxygen effect through normalization of the surviving tumor vasculature; and (3) synchronization of the cell cycle. Sorafenib and radiotherapy represent complementary strategies, as radiotherapy may be useful to prolong the effect of sorafenib through control of the macroscopic disease, when sorafenib may target latent microscopic disease. Sorafenib and radiotherapy associations are thus based on a relevant biological and clinical rationale and are being evaluated in ongoing phase I-II trials. (authors)

  2. Radiotherapy of esthesioneuroblastoma. Radiotherapie beim Aesthesioneuroblastom

    Energy Technology Data Exchange (ETDEWEB)

    Strnad, V. (Erlangen-Nuernberg Univ., Erlangen (Germany). Strahlentherapeutische Klinik und Poliklinik); Grabenbauer, G.G. (Erlangen-Nuernberg Univ., Erlangen (Germany). Strahlentherapeutische Klinik und Poliklinik); Dunst, J. (Erlangen-Nuernberg Univ., Erlangen (Germany). Strahlentherapeutische Klinik und Poliklinik); Sauer, R. (Erlangen-Nuernberg Univ., Erlangen (Germany). Strahlentherapeutische Klinik und Poliklinik)

    1994-02-01

    From 1985 through 1990, twelve patients with estehesioneuroblastoma have been treated at the Department of Radiotherapy at the University of Erlangen. Two had Kadish stage A, one stage B, and nine stage C. There were seven males and five females with a mean age of 43 years. Eleven patients had combined trancranial-transbasal surgery prior to radiotherapy (five R0-, four R1-, and two patients R2-resections) and one received radiotherapy only. The dose was 12 to 60 Gy (mean 54 Gy) in 1.8 Gy to 2 Gy per fraction. 8/12 patients (67%) were locally controlled. One had progressive disease during radiotherapy after partial resection and died. Three had local recurrences, one in-field and two marginal. One patient with a local recurrence developed cervical lymph node metastases, and one locally controlled patient developed bone metastases but is alive eight years after chemotherapy plus radiotherapy for metastatic disease. The five-year-overall and recurrence-free survival was 72% and 55%, respectively. (orig./MG)

  3. Implementation and evaluation of the quality control program of a system for image guided radiotherapy by megavoltage cone beam; Puesta en marcha y evaluacion del programa de control de calidad de un sistema de haz conico de megavoltaje para radioterapia guiada por la imagen

    Energy Technology Data Exchange (ETDEWEB)

    Castro Tejero, P.; Fernandez Leton, P.; Perez Moreno, J. M.; Zucca Aparicio, D.

    2009-07-01

    The use of image guided radiotherapy is essential in order to ensure the correct positioning of the patient prior to the delivery of the treatment. The most common procedure is the acquisition of two-dimensional orthogonal images that are compared with the corresponding digital images reconstructed by the treatment planning system. A recent technique, known as cone beam computed tomography, consists of three-dimensional image CT acquisition in the accelerator room by cone beam. This set of images is compared with the images used for the treatment planning. In our centre, the implementation of the M Vision system, including both techniques, has been carried out in two accelerators Siemens Oncor Expression. The quality control program associated with the M Vision system is presented in this work. The results obtained over a year since its implantation is also presented. (Author) 12 refs.

  4. Targeted tumor radiotherapy

    Directory of Open Access Journals (Sweden)

    Unak Perihan

    2002-01-01

    Full Text Available Targeted tumor radiotherapy is selectively delivery of curative doses of radiation to malignant sites. The aim of the targeted tumor radiotherapy is to use the radionuclides which have high LET particle emissions conjugated to appropriate carrier molecules. The radionuclides are selectively collected by tumor cells, depositing lethal doses to tumor cells while no admission occur to normal cells. In theory, targeted radiotherapy has several advantages over conventional radiotherapy since it allows a high radiation dose to be administered without causing normal tissue toxicity, although there are some limitations in the availability of appropriate targeting agents and in the calculations of administered doses. Therefore, for routine clinical applications more progress is still needed. In this article, the potential use of targeted tumor radiotherapy is briefly reviewed. More general aspects and considerations, such as potential radionuclides, mechanisms of tumor targeting was also outlined.

  5. Techniques of Proton Radiotherapy: Transport Theory

    CERN Document Server

    Gottschalk, Bernard

    2012-01-01

    These are notes for the lecture on Transport Theory in a one-week intensive course, "Techniques of Proton Radiotherapy". Topics are: Phase space diagrams: model beam line-effect of a scatterer-effect of a drift-the beam ellipse-phase space diagrams for the model beam line-emittance change in a drift-emittance change in a scatterer-phase space for a more realistic beam line-summary Miscellaneous topics: review of Gaussians-the Gaussian approximation to multiple Coulomb scattering (MCS)-relativistic single particle kinematics-completing the square-scattering power Fermi-Eyges theory: history-the basic theory-the beam ellipse-drawing the ellipse given the moments-ellipse examples-transporting the beam ellipse through a slab-emittance change in a drift-emittance change in a scatterer-differential form of the transport equations-equivalent sources-beam contained in the beam ellipse-summary Beam spreading in matter: theory of Preston and Koehler-generalization to heavy ions-experimental tests (Preston and Koehler, ...

  6. Prognostic Utility of Cell Cycle Progression Score in Men With Prostate Cancer After Primary External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Freedland, Stephen J., E-mail: steve.freedland@duke.edu [Department of Surgery, Durham VA Medical Center, Durham, North Carolina (United States); Department of Surgery (Urology), Duke University School of Medicine, Durham, North Carolina (United States); Department of Pathology, Duke University School of Medicine, Durham, North Carolina (United States); Gerber, Leah [Department of Surgery, Durham VA Medical Center, Durham, North Carolina (United States); Department of Surgery (Urology), Duke University School of Medicine, Durham, North Carolina (United States); Department of Pathology, Duke University School of Medicine, Durham, North Carolina (United States); Reid, Julia; Welbourn, William; Tikishvili, Eliso; Park, Jimmy; Younus, Adib; Gutin, Alexander; Sangale, Zaina; Lanchbury, Jerry S. [Myriad Genetics, Inc, Salt Lake City, Utah (United States); Salama, Joseph K. [Department of Radiation Oncology, Durham VA Medical Center, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Stone, Steven [Myriad Genetics, Inc, Salt Lake City, Utah (United States)

    2013-08-01

    Purpose: To evaluate the prognostic utility of the cell cycle progression (CCP) score, a RNA signature based on the average expression level of 31 CCP genes, for predicting biochemical recurrence (BCR) in men with prostate cancer treated with external beam radiation therapy (EBRT) as their primary curative therapy. Methods and Materials: The CCP score was derived retrospectively from diagnostic biopsy specimens of men diagnosed with prostate cancer from 1991 to 2006 (n=141). All patients were treated with definitive EBRT; approximately half of the cohort was African American. Outcome was time from EBRT to BCR using the Phoenix definition. Median follow-up for patients without BCR was 4.8 years. Association with outcome was evaluated by Cox proportional hazards survival analysis and likelihood ratio tests. Results: Of 141 patients, 19 (13%) had BCR. The median CCP score for patient samples was 0.12. In univariable analysis, CCP score significantly predicted BCR (P=.0017). The hazard ratio for BCR was 2.55 for 1-unit increase in CCP score (equivalent to a doubling of gene expression). In a multivariable analysis that included Gleason score, prostate-specific antigen, percent positive cores, and androgen deprivation therapy, the hazard ratio for CCP changed only marginally and remained significant (P=.034), indicating that CCP provides prognostic information that is not provided by standard clinical parameters. With 10-year censoring, the CCP score was associated with prostate cancer-specific mortality (P=.013). There was no evidence for interaction between CCP and any clinical variable, including ethnicity. Conclusions: Among men treated with EBRT, the CCP score significantly predicted outcome and provided greater prognostic information than was available with clinical parameters. If validated in a larger cohort, CCP score could identify high-risk men undergoing EBRT who may need more aggressive therapy.

  7. Benefit of Adjuvant Brachytherapy Versus External Beam Radiation for Early Breast Cancer: Impact of Patient Stratification on Breast Preservation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Grace L. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jiang, Jing [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Xu, Ying [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hoffman, Karen E. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Giordano, Sharon H. [Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hunt, Kelly K. [Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D., E-mail: bsmith3@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-02-01

    Purpose: Brachytherapy after lumpectomy is an increasingly popular breast cancer treatment, but data concerning its effectiveness are conflicting. Recently proposed “suitability” criteria guiding patient selection for brachytherapy have never been empirically validated. Methods: Using the Surveillance, Epidemiology, and End Results–Medicare linked database, we compared women aged 66 years or older with invasive breast cancer (n=28,718) or ductal carcinoma in situ (n=7229) diagnosed from 2002 to 2007, treated with lumpectomy alone, brachytherapy, or external beam radiation therapy (EBRT). The likelihood of breast preservation, measured by subsequent mastectomy risk, was compared by use of multivariate proportional hazards, further stratified by American Society for Radiation Oncology (ASTRO) brachytherapy suitability groups. We compared 1-year postoperative complications using the χ{sup 2} test and 5-year local toxicities using the log-rank test. Results: For patients with invasive cancer, the 5-year subsequent mastectomy risk was 4.7% after lumpectomy alone (95% confidence interval [CI], 4.1%-5.4%), 2.8% after brachytherapy (95% CI, 1.8%-4.3%), and 1.3% after EBRT (95% CI, 1.1%-1.5%) (P<.001). Compared with lumpectomy alone, brachytherapy achieved a more modest reduction in adjusted risk (hazard ratio [HR], 0.61; 95% CI, 0.40-0.94) than achieved with EBRT (HR, 0.22; 95% CI, 0.18-0.28). Relative risks did not differ when stratified by ASTRO suitability group (P=.84 for interaction), although ASTRO “suitable” patients did show a low absolute subsequent mastectomy risk, with a minimal absolute difference in risk after brachytherapy (1.6%; 95% CI, 0.7%-3.5%) versus EBRT (0.8%; 95% CI, 0.6%-1.1%). For patients with ductal carcinoma in situ, EBRT maintained a reduced risk of subsequent mastectomy (HR, 0.40; 95% CI, 0.28-0.55; P<.001), whereas the small number of patients treated with brachytherapy (n=179) precluded definitive comparison with lumpectomy alone

  8. Diffusion Weighted MRI as a predictive tool for effect of radiotherapy in locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Haack, Søren; Tanderup, Kari; Fokdal, Lars;

    Diffusion weighted MRI has shown great potential in diagnostic cancer imaging and may also have value for monitoring tumor response during radiotherapy. Patients with advanced cervical cancer are treated with external beam radiotherapy followed by brachytherapy. This study evaluates the value of ...

  9. Conformal radiotherapy of prostate carcinoma: Procedure description

    Directory of Open Access Journals (Sweden)

    Erak Marko

    2011-01-01

    Full Text Available Introduction. Today, three-dimensional conformal radiotherapy is a standard way in the radical treatment of localized prostate cancer, and it is an alternative to the radical prostatectomy. This method of radiotherapy treatment is widely accepted in the treatment of prostate cancer patients, and provides irradiation of targeted volume (prostate, seminal vesicles with dose escalation sparing the surrounding healthy tissues (rectum, bladder at the same time. That is not possible with the conventional twodimension technique. Procedure description. Three-dimensional conformal radiotherapy is a volumetric, visual simulation according to the computed tomography slices; it defines the tumour and organ at risk individually in each patient. Results of several studies have shown that there is a significant decrease in the development of acute toxicity when prostate cancer patients are treated with conformal radiotherapy. High dose irradiation gives excellent results in treatment of localized prostate carcinoma and improves treatment results in the patients with locally advanced carcinoma of prostate. Discussion. Prostate carcinoma irradiation techniques have been changed dramatically during recent years. Data obtained by computed tomography are important since the size and shapes of the prostate as well as its anatomic relations towards the rectum and bladder are considerably different in individual patients. The three-dimension plan of irradiation can be designed for each patient individually by performing computed tomography technique when planning radiotherapy. Conclusion. The advanced planning systems for conformal radiotherapy can reconstruct the anatomic structures of pelvis in three-dimension technique on the basis of computed tomography scans, which provides better conformality between the irradiation beam and geometrical shape of the tumour with minimal irradiation of the surrounding healthy tissue.

  10. Partial breast radiotherapy with simple teletherapy techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fekete, Gábor; Újhidy, Dóra; Együd, Zsófia; Kiscsatári, Laura; Marosi, Gusztáv; Kahán, Zsuzsanna; Varga, Zoltán, E-mail: varga.zoltan@med.u-szeged.hu

    2015-01-01

    A prospective pilot study of partial breast irradiation (PBI) with conventional vs hypofractionated schedules was set out. The study aimed to determine efficacy, acute and late side effects, and the preference of photon vs electron irradiation based on individual features. Patients were enrolled according to internationally accepted guidelines on PBI. Conformal radiotherapy plans were generated with both photon and electron beams, and the preferred technique based on dose homogeneity and the radiation exposure of healthy tissues was applied. For electron dose verification, a special phantom was constructed. Patients were randomized for fractionation schedules of 25 × 2 vs 13 × 3 Gy. Skin and breast changes were registered at the time of and ≥1 year after the completion of radiotherapy. Dose homogeneity was better with photons. If the tumor bed was located in the inner quadrants, electron beam gave superior results regarding conformity and sparing of organ at risk (OAR). If the tumor was situated in the lateral quadrants, conformity was better with photons. A depth of the tumor bed ≥3.0 cm predicted the superiority of photon irradiation (odds ratio [OR] = 23.6, 95% CI: 5.2 to 107.5, p < 0.001) with >90% sensitivity and specificity. After a median follow-up of 39 months, among 72 irradiated cases, 1 local relapse out of the tumor bed was detected. Acute radiodermatitis of grade I to II, hyperpigmentation, and telangiectasia developed ≥1 year after radiotherapy, exclusively after electron beam radiotherapy. The choice of electrons or photons for PBI should be based on tumor bed location; the used methods are efficient and feasible.

  11. Partial breast radiotherapy with simple teletherapy techniques.

    Science.gov (United States)

    Fekete, Gábor; Újhidy, Dóra; Együd, Zsófia; Kiscsatári, Laura; Marosi, Gusztáv; Kahán, Zsuzsanna; Varga, Zoltán

    2015-01-01

    A prospective pilot study of partial breast irradiation (PBI) with conventional vs hypofractionated schedules was set out. The study aimed to determine efficacy, acute and late side effects, and the preference of photon vs electron irradiation based on individual features. Patients were enrolled according to internationally accepted guidelines on PBI. Conformal radiotherapy plans were generated with both photon and electron beams, and the preferred technique based on dose homogeneity and the radiation exposure of healthy tissues was applied. For electron dose verification, a special phantom was constructed. Patients were randomized for fractionation schedules of 25 × 2 vs 13 × 3Gy. Skin and breast changes were registered at the time of and ≥1 year after the completion of radiotherapy. Dose homogeneity was better with photons. If the tumor bed was located in the inner quadrants, electron beam gave superior results regarding conformity and sparing of organ at risk (OAR). If the tumor was situated in the lateral quadrants, conformity was better with photons. A depth of the tumor bed ≥3.0cm predicted the superiority of photon irradiation (odds ratio [OR] = 23.6, 95% CI: 5.2 to 107.5, p 90% sensitivity and specificity. After a median follow-up of 39 months, among 72 irradiated cases, 1 local relapse out of the tumor bed was detected. Acute radiodermatitis of grade I to II, hyperpigmentation, and telangiectasia developed ≥1 year after radiotherapy, exclusively after electron beam radiotherapy. The choice of electrons or photons for PBI should be based on tumor bed location; the used methods are efficient and feasible.

  12. Concomitant chemo-radiotherapy for locally advanced bronchial cancer: impact of radiotherapy quality on global survival: results of a trial by the Thoracic Cancerology French-speaking Inter-group (IFCT) and Pneumo-Cancerology French Group (GFPC) 02.01; Chimioradiotherapie concomitante pour cancer bronchique localement evolue: impact de la qualite de la radiotherapie sur la survie globale: resultats de l'essai de l'Intergroupe francophone de cancerologie thoracique (IFCT) et du Groupe francais de pneumo-cancerologie (GFPC) 02.01

    Energy Technology Data Exchange (ETDEWEB)

    Martel-Lafay, I.; Montella, A.; Pommier, P. [Centre Leon-Berard, 69 - Lyon (France); Clavere, P. [CHU de Limoges, 87 - Limoges (France); Labat, J.P. [CHU de Brest, 29 - (France); Benchalal, M. [Centre Eugene-Marquis, 35 - Renne (France); Teissier, E. [Centre azureen de radiotherapie, 06 - Mougins (France); Talabard, J.N.; Fournel, P. [CHU de Saint- Etienne, 42 - Saint- Etienne (France); D' Hombres, A. [Centre hospitalier Lyon Sud, 69 - Pierre-Benite (France)

    2010-10-15

    The author report the assessment of the influence of radiotherapy quality and of its consequences on the future of 113 patients during a phase-II randomized trial of concomitant chemo-radiotherapy of bronchial cancers without stage-II non-resectable small cells. The patients have been submitted to a conformational radiotherapy and a concomitant induction of consolidation chemotherapy. Ten items are analysed: immobilisation, dose per fraction, total dose, ganglion radiotherapy, number of beams, images before and after radiotherapy, radiotherapy duration, duration without radiotherapy, dose-lung volume histogram. The study notably shows the deleterious effects of an interruption of the concomitant chemotherapy on the global survival. Short communication

  13. Surface dose in intracavitary orthovoltage radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Podgorsak, M.B.; Schreiner, L.J.; Podgorsak, E.B. (Department of Physics, McGill University, Montreal, PQ (Canada) Department of Radiation Oncology, McGill University, Montreal, PQ (Canada))

    1990-07-01

    Radiotherapy with orthovoltage techniques is often the prime treatment for localized superficial malignancies. Surface doses and depth doses measured with cylindrical and end-window Farmer chambers are presented for various orthovoltage x-ray beams in the range from 80 to 300 kVp, both for open beams and beams collimated with commercial intracavitary leaded-glass cones. For radiation fields collimated by a diaphragm positioned at a distance from the patient surface (open beams) there is a small skin-sparing effect. On the other hand, the surface doses with commercial leaded-glass intracavitary cones can exhibit a fivefold increase compared to the open-beam dose maxima. Beyond a depth of {similar to}0.2 mm in a tissue-equivalent phantom, the doses measured for open beams and beams collimated with intracavitary cones are essentially identical. The increase in the surface dose observed with intracavitary cones is attributed to photoelectrons and recoil electrons produced in the cones. The high surface doses are measured by thin-wall parallel-plate ionization chambers but cannot be measured with cylindrical Farmer chambers since these chambers have wall thicknesses too large for the transmission of electrons produced in the cone. Since cylindrical Farmer chambers are typically used for calibration of radiation output, the high surface doses produced by the intracavitary cones may be overlooked; they can, however, be reduced to open-beam values by simple modifications to the cones.

  14. 锥形束 CT 引导全乳调强放疗摆位误差自适应的预测与校正%Cone beam CT-derived adaptive radiotherapy for setup error assessment and correction in whole ;breast intensity modulated radiotherapy

    Institute of Scientific and Technical Information of China (English)

    王玮; 李建彬; 徐敏; 邵倩; 范廷勇; 张英杰; 邢军; 胡宏光

    2016-01-01

    Objective To quantify the setup error ( SE ) in breast cancer patients treated with intensity modulated radiotherapy (IMRT) based on cone beam CT (CBCT), and to explore the feasibility of using several CBCT scans to presume and correct SE in the treatment for breast cancer patients.Methods Eighteen breast cancer patients after breast conserving surgery who underwent whole breast IMRT were included in this study.Three dimensional interfraction motion before and after on-line CBCT-based corrections were quantified.The on-line CBCT-based corrections were performed using automated greyscale match.The system SE (Σ) and random error (σ) were calculated for each patient based on the consecutive multiple online scanning based on CBCT (≥5) .The trends in magnitudes of Σand σwere assessed during the treatment. Results The magnitude variation ofΣwas less than 1 mm before and after on-line CBCT-based corrections. As the CBCT scanning times increase ( before 10 times ) , the Σin anteroposterior ( AP ) direction was increased significantly, and σin three dimensional directions was also increased after 7 times of CBCT scanning.After on-line CBCT-based corrections, theΣshowed a steady trend by variation near zero for the first 20 times irradiation;but after 20 times, theΣin AP and superoinferior ( SI) directions was increased slightly (less than 0.5 mm), and σdecreased in three-dimensional directions.There were no significant differences forΣ,σand setup margin ( SM) before and after on-line CBCT-based corrections in all three directions ( P>0.05) .Conclusions For breast cancer patients who underwent IMRT after breast conserving surgery, the setup error is relatively stable during the whole irradiation.The first 5 CBCT scans are suitable to presume and correct SE, and also can be used as the right time for adaptive radiotherapy planning revision.%目的:基于锥形束CT( CBCT)建立乳腺癌保乳术后全乳调强放疗( IMRT)疗程中患者分次间摆

  15. Oncological results, functional outcomes and health-related quality-of-life in men who received a radical prostatectomy or external beam radiation therapy for localized prostate cancer: a study on long-term patient outcome with risk stratification

    Institute of Scientific and Technical Information of China (English)

    Itsuhiro Takizawa; Noboru Hara; Tsutomu Nishiyama; Masaaki Kaneko; Tatsuhiko Hoshii; Emiko Tsuchida; Kota Takahashi

    2009-01-01

    Health-related quality-of-life (HRQOL) after a radical prostatectomy (RP) or external beam radiation therapy (EBRT) has not been studied in conjunction with oncological outcomes in relation to disease risk stratification. Moreover, the long-term outcomes of these treatment approaches have not been studied. We retrospectively analyzed ontological outcomes between consecutive patients receiving RP (n=86) and EBRT (n=76) for localized prostate cancer. HRQOL and functional outcomes could be assessed in 62 RP (79%) and 54 EBRT (79%) patients over a 3-year follow-up period (median: 41 months) using the Medical Outcomes Study Short Form-36 (SF-36) and the University of California Los Angeles Prostate Cancer Index (UCLA PCI). The 5-year biochemical progression-free survival did not differ between the RP and EBRT groups for low-risk (74.6% vs. 75.0%, P=0.931) and intermediate-risk (61.3% vs. 71.1%, P=0.691) patients. For high-risk patients, progression-free survival was lower in the RP group (45.1%) than in the EBRT group (79.7%) (P=0.002). The general HRQOL was comparable between the two groups. Regarding functional outcomes, the RP group reported lower scores on urinary function and less urinary bother and sexual bother than the EBRT group (P<0.001, P<0.05 and P<0.001, respectively). With risk stratification, the low-and intermediate-risk patients in the RP group reported poorer urinary function than patients in the EBRT group (P<0.001 for each). The sexual function of the high-risk patients in the EBRT group was better than that of the same risk RP patients (P<0.001). Biochemical recurrence was not associated with the UCLA PCI score in either group. In conclusion, low- to intermediate-risk patients treated with an RP may report relatively decreased urinary function during long-term follow-up. The patient's HRQOL after treatment did not depend on biochemical recurrence.

  16. Total heart volume as a function of clinical and anthropometric parameters in a population of external beam radiation therapy patients

    Science.gov (United States)

    Nadège Ilembe Badouna, Audrey; Veres, Cristina; Haddy, Nadia; Bidault, François; Lefkopoulos, Dimitri; Chavaudra, Jean; Bridier, André; de Vathaire, Florent; Diallo, Ibrahima

    2012-01-01

    The aim of this paper was to determine anthropometric parameters leading to the least uncertain estimate of heart size when connecting a computational phantom to an external beam radiation therapy (EBRT) patient. From computed tomography images, we segmented the heart and calculated its total volume (THV) in a population of 270 EBRT patients of both sexes, aged 0.7-83 years. Our data were fitted using logistic growth functions. The patient age, height, weight, body mass index and body surface area (BSA) were used as explanatory variables. For both genders, good fits were obtained with both weight (R2 = 0.89 for males and 0.83 for females) and BSA (R2 = 0.90 for males and 0.84 for females). These results demonstrate that, among anthropometric parameters, weight plays an important role in predicting THV. These findings should be taken into account when assigning a computational phantom to a patient.

  17. Film dosimetry in conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Danciu, C.; Proimos, B.S. [Patras Univ. (Greece). Dept. of Medical Physics

    1995-12-01

    Dosimetry, through a film sandwiched in a transverse cross-section of a solid phantom, is a method of choice in Conformal Radiotherapy because: (a) the blackness (density) of the film at each point offers a measure of the total dose received at that point, and (b) the film is easily calibrated by exposing a film strip in the same cross-section, through a stationary field. The film must therefore have the following properties: (a) it must be slow, in order not to be overexposed, even at a therapeutic dose of 200 cGy, and (b) the response of the film (density versus dose curve) must be independent of the photon energy spectrum. A few slow films were compared. It was found that the Kodak X-Omat V for therapy verification was the best choice. To investigate whether the film response was independent of the photon energy, response curves for six depths, starting from the depth of maximum dose to the depth of 25 cm, in solid phantom were derived. The vertical beam was perpendicular to the anterior surface of the phantom, which was at the distance of 100 cm from the source and the field was 15x15 cm at that distance. This procedure was repeated for photon beams emitted by a Cobalt-60 unit, two 6 MV and 15 MV Linear Accelerators, as well as a 45 MV Betatron. For each of those four different beams the film response was the same for all six depths. The results, as shown in the diagrams, are very satisfactory. The response curve under a geometry similar to that actually applied, when the film is irradiated in a transverse cross-section of the phantom, was derived. The horizontal beam was almost parallel (angle of 85) to the plane of the film. The same was repeated with the central ray parallel to the film (angle 90) and at a distance of 1.5 cm from the horizontal film. The field size was again 15x15 at the lateral entrance surface of the beam. The response curves remained the same, as when the beam was perpendicular to the films.

  18. Prognostic Impact of External Beam Radiation Therapy in Patients Treated With and Without Extended Surgery and Intraoperative Electrons for Locally Recurrent Rectal Cancer: 16-Year Experience in a Single Institution

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Felipe A. [Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); Institute of Research Investigation, Hospital General Universitario Gregorio Marañón, Madrid (Spain); School of Medicine, Complutense University, Madrid (Spain); Sole, Claudio V., E-mail: cvsole@uc.cl [Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); Institute of Research Investigation, Hospital General Universitario Gregorio Marañón, Madrid (Spain); School of Medicine, Complutense University, Madrid (Spain); Service of Radiation Oncology, Instituto de Radiomedicina, Santiago (Chile); Alvarez de Sierra, Pedro [Service of General Surgery, Hospital General Universitario Gregorio Marañón, Madrid (Spain); School of Medicine, Complutense University, Madrid (Spain); Gómez-Espí, Marina [Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); Service of Radiation Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); Institute of Research Investigation, Hospital General Universitario Gregorio Marañón, Madrid (Spain); Blanco, Jose [Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); Institute of Research Investigation, Hospital General Universitario Gregorio Marañón, Madrid (Spain); and others

    2013-08-01

    Purpose: To analyze prognostic factors associated with survival in patients after intraoperative electrons containing resective surgical rescue of locally recurrent rectal cancer (LRRC). Methods and Materials: From January 1995 to December 2011, 60 patients with LRRC underwent extended surgery (n=38: multiorgan [43%], bone [28%], soft tissue [38%]) or nonextended (n=22) surgical resection, including a component of intraoperative electron-beam radiation therapy (IOERT) to the pelvic recurrence tumor bed. Twenty-eight (47%) of these patients also received external beam radiation therapy (EBRT) (range, 30.6-50.4 Gy). Survival outcomes were estimated by the Kaplan-Meier method, and risk factors were identified by univariate and multivariate analyses. Results: The median follow-up time was 36 months (range, 2-189 months), and the 1-year, 3-year, and 5-year rates for locoregional control (LRC) and overall survival (OS) were 86%, 52%, and 44%; and 78%, 53%, 43%, respectively. On multivariate analysis, R1 resection, EBRT at the time of pelvic rerecurrence, no tumor fragmentation, and non-lymph node metastasis retained significance with regard to LRR. R1 resection and no tumor fragmentation showed a significant association with OS after adjustment for other covariates. Conclusions: EBRT treatment integrated for rescue, resection radicality, and not involved fragmented resection specimens are associated with improved LRC in patients with locally recurrent rectal cancer. Additionally, tumor fragmentation could be compensated by EBRT. Present results suggest that a significant group of patients with LRRC may benefit from EBRT treatment integrated with extended surgery and IOERT.

  19. Radiotherapy for the medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Gose, Kyuhei; Imajo, Yoshinari; Imanaka, Kazufumi (Kobe Univ. (Japan). School of Medicine)

    1983-08-01

    Eighteen patients with medulloblastoma, treated between 1972 and 1981, at Kobe University School of Medicine, were retrospectively studied. Of those completing post operative irradiation, 50% have survived for 2 years, 15% for 5 years and mean survival periods was 22.2 months. 13 out of 18 patients developed local recurrence and spinal dissemination. The mean time from the initial radiotherapy to recurrence was 8.5 months. It was suggested that posterior fossa should recieve 5,000 rad, the spine should 2,000 rad and recurrences should be treated by the combination of radiotherapy and chemotherapy.

  20. Xerostomia induced by radiotherapy

    Directory of Open Access Journals (Sweden)

    Alimi D

    2015-08-01

    Full Text Available David Alimi Department of Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USAWe read with great interest the excellent review on xerostomia induced by radiotherapy, by Pinna et al.1 The authors should be congratulated for a very detailed review of the physiopathology, clinical symptoms, and therapeutic management of an extremely difficult condition. Although we agree that the use of anticholinergic medication represents treatment, it requires the patient to have residual salivary gland function. Unfortunately, it is well established that in most cases radiotherapy destroys most of the salivary gland and associated salivary secretions.     

  1. Erythropoietin and radiotherapy; Erythropoietine et radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Le Fur, E.; Albarghach, M.N.; Pradier, O. [CHU de Morvan, Dept. de radiotherapie, 29 - Brest (France)

    2010-01-15

    Erythropoietin (E.P.O.) is a glycoprotein hormone. This hormone is a growth factor for red blood cells precursors in the bone marrow. The decrease of oxygen partial pressure, a reduced number of erythrocytes caused by bleeding or excessive destruction, or increased tissues oxygen requirements lead to increased secretion of E.P.O.. Its action takes place on bone marrow erythroblastic cells through specific receptors. E.P.O. stimulates the proliferation of red cell precursors stem cells in the bone marrow, thus increasing their production in one to two weeks. The effectiveness of E.P.O. at increasing haemoglobin and improving patients quality of life has been demonstrated by several studies. However, its use in radiotherapy remains controversial. While tumour hypoxia caused by anaemia is a factor of radio resistance and thus a source of local failure, tumour expression of E.P.O. receptors presents a significant risk for tumour progression and neo-angiogenesis, which would be increased during the administration of E.P.O.. The purpose of this article is to answer the question: is there a place for E.P.O. in combination with radiotherapy in the management of cancer?

  2. Hormonal cytoreduction and radiotherapy for carcinoma of the prostate

    Energy Technology Data Exchange (ETDEWEB)

    Shearer, R.J.; Davies, J.H.; Gelister, J.S.K.; Dearnaley, D.P. (Royal Marsden Hospital, London (United Kingdom))

    1992-05-01

    We report the effect on prostatic volume of the administration of the luteinising hormone-releasing hormone (LHRH) analogue goserelin in 22 patients with locally advanced carcinoma of the prostrate; 20 achieved a significant reduction in volume, the median volume being 66 ml before treatment and 30 ml after 17 weeks. If used before external beam radiotherapy (RT), volume reduction will permit smaller boost fields and thus potentially reduce adverse radiotherapy effects. In addition, reducing tumour volume before RT may lead to an increase in local control. We discuss the possible role of hormonal volume reduction in the management of prostatic cancer. (Author).

  3. Radiotherapy for craniopharyngioma.

    Science.gov (United States)

    Aggarwal, Ajay; Fersht, Naomi; Brada, Michael

    2013-03-01

    Radiotherapy remains the mainstay of multidisciplinary management of patients with incompletely resected and recurrent craniopharyngioma. Advances in imaging and radiotherapy technology offer new alternatives with the principal aim of improving the accuracy of treatment and reducing the volume of normal brain receiving significant radiation doses. We review the available technologies, their technical advantages and disadvantages and the published clinical results. Fractionated high precision conformal radiotherapy with image guidance remains the gold standard; the results of single fraction treatment are disappointing and hypofractionation should be used with caution as long term results are not available. There is insufficient data on the use of protons to assess the comparative efficacy and toxicity. The precision of treatment delivery needs to be coupled with experienced infrastructure and more intensive quality assurance to ensure best treatment outcome and this should be carried out within multidisciplinary teams experienced in the management of craniopharyngioma. The advantages of the combined skills and expertise of the team members may outweigh the largely undefined clinical gain from novel radiotherapy technologies.

  4. Scattered radiation from applicators in clinical electron beams.

    NARCIS (Netherlands)

    Battum, L.J. van; Zee, W. van der; Huizenga, H.

    2003-01-01

    In radiotherapy with high-energy (4-25 MeV) electron beams, scattered radiation from the electron applicator influences the dose distribution in the patient. In most currently available treatment planning systems for radiotherapy this component is not explicitly included and handled only by a slight

  5. [Radiotherapy for Graves' ophthalmopathy].

    Science.gov (United States)

    Kuhnt, T; Müller, A C; Janich, M; Gerlach, R; Hädecke, J; Duncker, G I W; Dunst, J

    2004-11-01

    Graves' ophthalmopathy (GO) is the most frequent extrathyroidal manifestation of Graves' disease, an autoimmune disorder of the thyroid, whereas the precise pathogenesis still remains unclear. In Hashimoto's thyroiditis the occurrence of proptosis is an extremely rare event. The therapy for middle and severe courses of GO shows in partly disappointing results, although several therapy modalities are possible (glucocorticoid therapy, radiotherapy, antithyroid drug treatment, surgery). All these therapies lead in only 40 - 70 % to an improvement of the pathogenic symptoms. An intensive interdisciplinary cooperation is necessary to satisfy the requirements for the treatment of Graves' ophthalmopathy. As a consequence of the very different results of the few of clinical studies that were accomplished with reference to this topic, treatment by radiotherapy in the management of the disease is presently controversially discussed. In the German-speaking countries the radiotherapy is, however, firmly established as a therapy option in the treatment of the moderate disease classes (class 2-5 according to NO SPECS), especially if diplopia is present. This article describes the sequences, dosages and fractionation schemes as well as the risks and side effects of the radiotherapy. Altogether, radiotherapy is assessed as an effective and sure method. The administration of glucocorticoids can take place before the beginning of or during the radiotherapy. For the success of treatment the correct selection of patients who may possibly profit from a radiotherapy is absolutely essential. By realising that GO proceeds normally over a period of 2-5 years, which is followed by a period of fibrotic alteration, the application of the radiotherapy in the early, active phase is indispensable. A precise explanation for the effects of radiotherapy in treatment of the GO does not exist at present. The determination of the most effective irradiation doses was made from retrospectively evaluated

  6. Current concepts on imaging in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lecchi, Michela; Elisei, Federica; Lucignani, Giovanni [University of Milan, Institute of Radiological Sciences, Milan (Italy); San Paolo Hospital, Unit of Nuclear Medicine, Milan (Italy); Fossati, Piero [University of Milan, Institute of Radiological Sciences, Milan (Italy); CNAO Foundation, Milan (Italy); Orecchia, Roberto [University of Milan, Institute of Radiological Sciences, Milan (Italy); CNAO Foundation, Milan (Italy); European Institute of Oncology, Department of Radiation Oncology, Milan (Italy)

    2008-04-15

    New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy. (orig.)

  7. Current concepts on imaging in radiotherapy.

    Science.gov (United States)

    Lecchi, Michela; Fossati, Piero; Elisei, Federica; Orecchia, Roberto; Lucignani, Giovanni

    2008-04-01

    New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy.

  8. Role of palliative radiotherapy in brain metastases

    Directory of Open Access Journals (Sweden)

    Ramesh S Bilimagga

    2009-01-01

    Full Text Available Background: Brain metastases are a common manifestation of systemic cancer and exceed primary brain tumors in number and are a significant cause of neurologic problems. They affect 20-40% of all cancer patients. Aggressive management of brain metastases is effective in both symptom palliation and prolonging the life. Radiotherapy has a major role to play in the management of brain metastases. AIM: The aim of the study was to know the outcome of palliative radiotherapy in symptomatic brain metastases in terms of improvement in their performance status. Materials and Methods: This is a retrospective study of 63 patients diagnosed to have brain metastases and treated with palliative whole brain radiotherapy to a dose of 30 Gy in 10 fractions over two weeks between June 1998 and June 2007. Diagnosis was done in most of the cases with computed tomography scan and in a few with magnetic resonance imaging. Improvement in presenting symptoms has been assessed in terms of improvement in their performance status by using the ECOG scale. Results: Fifty-four patients completed the planned treatment. Eight patients received concurrent Temozolamide; 88% of patients had symptom relief at one month follow-up; 39/54 patients had a follow-up of just one to three months. Hence survival could not be assessed in this study. Conclusion: External beam radiotherapy in the dose of 30 Gy over two weeks achieved good palliation in terms improvement in their performance status in 88% of patients. Addition of concurrent and adjuvant Timozolamide may improve the results.

  9. Mathematical modeling of brain tumors: effects of radiotherapy and chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Powathil, G [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Kohandel, M [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Sivaloganathan, S [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Oza, A [Center for Mathematical Medicine, Fields Institute for Research in Mathematical Sciences, Toronto, Ontario M5T 3J1 (Canada); Milosevic, M [Radiation Medicine Program, Princess Margaret Hospital, and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)

    2007-06-07

    Gliomas, the most common primary brain tumors, are diffusive and highly invasive. The standard treatment for brain tumors consists of a combination of surgery, radiation therapy and chemotherapy. Over the past few years, mathematical models have been applied to study untreated and treated brain tumors. In an effort to improve treatment strategies, we consider a simple spatio-temporal mathematical model, based on proliferation and diffusion, that incorporates the effects of radiotherapeutic and chemotherapeutic treatments. We study the effects of different schedules of radiation therapy, including fractionated and hyperfractionated external beam radiotherapy, using a generalized linear quadratic (LQ) model. The results are compared with published clinical data. We also discuss the results for combination therapy (radiotherapy plus temozolomide, a new chemotherapy agent), as proposed in recent clinical trials. We use the model to predict optimal sequencing of the postoperative (combination of radiotherapy and adjuvant, neo-adjuvant or concurrent chemotherapy) treatments for brain tumors.

  10. The physics of radiotherapy X-rays and electrons

    CERN Document Server

    Metcalfe, Peter; Hoban, Peter

    2012-01-01

    The Physics of Radiotherapy X-Rays and Electrons is an updated successor to The Physics of Radiotherapy X-Rays from Linear Accelerators published in 1997. This new volume includes a significant amount of new material, including new chapters on electrons in radiotherapy and IMRT, IGRT, and tomotherapy, which have become key developments in radiation therapy. Also updated from the earlier edition are the physics beam modeling chapters, including Monte Carlo methods, adding those mysterious electrons, as well as discourse on radiobiological modeling including TCP, NTCP, and EUD and the impact of these concepts on plan analysis and inverse planning. This book is intended as a standard reference text for postgraduate radiation oncology medical physics students. It will also be of interest to radiation oncology registrars and residents, dosimetrists, and radiation therapists. The new text contains review questions at the end of each chapter and full bibliographic entries. Fully indexed. Selected questions and ans...

  11. Dose masking feature for BNCT radiotherapy planning

    Science.gov (United States)

    Cook, Jeremy L.; Wessol, Daniel E.; Wheeler, Floyd J.

    2000-01-01

    A system for displaying an accurate model of isodoses to be used in radiotherapy so that appropriate planning can be performed prior to actual treatment on a patient. The nature of the simulation of the radiotherapy planning for BNCT and Fast Neutron Therapy, etc., requires that the doses be computed in the entire volume. The "entire volume" includes the patient and beam geometries as well as the air spaces in between. Isodoses derived from the computed doses will therefore extend into the air regions between the patient and beam geometries and thus depict the unrealistic possibility that radiation deposition occurs in regions containing no physical media. This problem is solved by computing the doses for the entire geometry and then masking the physical and air regions along with the isodose contours superimposed over the patient image at the corresponding plane. The user is thus able to mask out (remove) the contour lines from the unwanted areas of the image by selecting the appropriate contour masking region from the raster image.

  12. Long-term follow-up after modern radical prostate cancer radiotherapy

    DEFF Research Database (Denmark)

    Sander, Lotte

    A significant increase in the prostate cancer incidence has made prostate cancer a major health problem in recent years. Because of the often but unfortunately not always indolent nature of the disease, over-diagnosis and over-treatment are relevant clinical and ethic dilemmas. External beam...... radiotherapy is a well established treatment modality for prostate cancer. Accuracy and precision are key words with regard to optimal survival and minimal toxicity in modern radiotherapy and are fundamentals in modern radiotherapy. Modern imaging has improved the ability to define radiotherapy target volumes....... Especially treatment margins have been reduced through the use of more accurate treatment planning and image-guided technology. Increasing doses have lead to increased disease control. Aiming for minimal toxicity after radiotherapy, magnetic resonance imaging delineation could be a possible tool, knowing...

  13. Melanoma: Last call for radiotherapy.

    Science.gov (United States)

    Espenel, Sophie; Vallard, Alexis; Rancoule, Chloé; Garcia, Max-Adrien; Guy, Jean-Baptiste; Chargari, Cyrus; Deutsch, Eric; Magné, Nicolas

    2017-02-01

    Melanoma is traditionally considered to be a radioresistant tumor. However, radiotherapy and immunotherapy latest developments might upset this radiobiological dogma. Stereotactic radiotherapy allows high dose per fraction delivery, with high dose rate. More DNA lethal damages, less sublethal damages reparation, endothelial cell apoptosis, and finally clonogenic cell dysfunction are produced, resulting in improved local control. Radiotherapy can also enhance immune responses, inducing neoantigens formation, tumor antigen presentation, and cytokines release. A synergic effect of radiotherapy with immunotherapy is expected, and might lead to abscopal effects. If hadrontherapy biological properties seem able to suppress hypoxia-induced radioresistance and increase biological efficacy, ballistic advantages over photon radiations might also improve radiotherapy outcomes on usually poor prognosis locations. The present review addresses biological and clinical effects of high fraction dose, bystander effect, abscopal effect, and hadrontherapy features in melanoma. Clinical trials results are warranted to establish indications of innovative radiotherapy in melanoma.

  14. Radiotherapy of vertebral hemangiomas

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, Kohichi; Hareyama, Masato; Oouchi, Atushi; Sido, Mitsuo; Nagakura, Hisayasu; Tamakawa, Mituharu; Akiba, Hidenari; Morita, Kazuo [Dept. of Radiology, Sapporo Medical Univ., School of Medicine (Japan)

    1997-12-31

    Between 1975 and 1996, 14 patients (11 females, 3 males) with vertebral hemangioma received treatment with radiotherapy. Thirteen patients had a history of back pain or lumbago and 2 patients had neurological symptoms such as sensory impairment or paraplegia. The standard dose administered was 36 Gy in 18 fractions (five treatments per week). In the 13 patients with pain, this was completely or partially relieved. The condition of a man with hypesthesia of the legs deteriorated and a woman with paraplegia who was treated with decompressive laminectomy followed by radiotherapy recovered completely after irradiation. CT scan before irradiation showed thickened trabeculae as small punctate areas of sclerosis in all patients. At MR imaging before irradiation, T2-weighted MR images showed areas of high intensity in all patients and MR images demonstrated lesion enhancement. However, none of the patients who were treated successfully with radiation demonstrated any changes of the affected vertebra in the conventional radiographic films, CT scan or MR imaging, even 5 years after irradiation. Radiological imaging is indispensable for the diagnosis of vertebral hemangiomas but does not appear to be useful for evaluating the effects of radiotherapy. (orig.).

  15. Paired observation of californium-252 neutron intraluminal brachytherapy combined with external-beam radiotherapy with and without lead shielding for cervical cancer%252 Cf中子腔内照射结合挡铅与不挡铅外照射治疗宫颈癌的配对观察

    Institute of Scientific and Technical Information of China (English)

    戴卓捷; 雷新; 陈永红; 刘佳

    2015-01-01

    目的:比较252 Cf中子腔内照射结合挡铅盆腔对穿野和不挡铅箱式四野外照射治疗宫颈癌的治疗结果。方法2004—2007年本院收治的Ⅱa—Ⅲb 期的宫颈鳞癌患者,按照临床分期、年龄、肿瘤大小、贫血程度为配对条件,共筛选出26对(52例)研究对象,分为挡铅盆腔对穿野组(挡铅组)和不挡铅箱式四野组(不挡铅组)。两组患者外照射期间穿插252 Cf中子后装治疗。 Kaplan?Meier法计算5年LC、OS、DFS 并 Logrank 检验差异,晚期并发症发生率差异行 McNemar 法检验。结果挡铅、不挡铅组5年LC 率分别为85%、81%(P=0??014),OS 率分别为89%、73%(P=0??013),DFS 率分别为89%、73%(P=0??013),晚期并发症发生率分别为12%、23%(P=0??008)。结论腔内照射结合外照射治疗宫颈癌时无论采取对穿野还是箱式四野,后程前后野中央均应挡铅。%Objective To compare the efficacy between californium?252 ( 252 Cf ) neutron intraluminal brachytherapy combined with external?beam radiotherapy with lead?shielding pelvic parallel opposing field technique and non?lead?shielding four?field box technique for cervical cancer. Methods A total of 52 patients with stage Ⅱa?Ⅲb cervical squamous cell carcinoma who were admitted to our hospital from 2004 to 2007 were enrolled as subjects and paired by clinical stage, age, tumor size, and degree of anemia. The 26 pairs of patients were divided into lead?shielding pelvic parallel opposing field group (lead?shielding group) and non?lead?shielding four?field box group (non?lead?shielding group). For all patients in both groups, 252 Cf neutron brachytherapy was added in external?beam radiotherapy. The local control (LC), overall survival (OS), and disease?free survival (DFS) rates were calculated using the Kaplan?Meier method and analyzed using the log?rank test. The difference in the incidence of late complications was

  16. Dosimetry at the location of secondary tumors after radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Baas, H.W.; Davelaar, J.J.; Broerse, J.J.; Noordijk, E.M. [University Hospital, Leiden (Netherlands). Dept. of Clinical Oncology

    1995-12-01

    After a latency period of many years the incidence of a secondary tumor is considered a serious late effect of radiotherapy. Analysis of about 200 patients, treated by radiotherapy for Hodgkin`s disease in our hospital, shows an actuarial risk for the incidence of a secondary tumor of about 7% after 10 years. The chance of tumor induction depends on the dose at the location of the tumor and therefore a good dose estimation is mandatory. Radiotherapy was given with Co-60 in the early years and with linear accelerators thereafter, exposing the target areas to 36 - 40 Gy. For dose estimations at the penumbra and outside the beam, where tumor incidence is expected to be high, we used a.o. Monte Carlo calculations. We developed an EGS4 computer simulation for a treatment beam from a linear accelerator irradiating a mathematical phantom representing the patient geometry (GSF ADAM phantom). The isodose curves at certain energies were obtained for a water phantom and fitted quite well with measurements. In addition to Monte Carlo calculations we also used existing treatment planning systems. The dose estimations of a number of patients and the derived risk per unit of dose, which is important for both radiotherapy as well as radiation protection in general, is discussed.

  17. A new lead-free radiation shielding material for radiotherapy.

    Science.gov (United States)

    Yue, Kun; Luo, Wenyun; Dong, Xiaoqing; Wang, Chuanshan; Wu, Guohua; Jiang, Mawei; Zha, Yuanzi

    2009-02-01

    Lead has recently been recognised as a source of environmental pollution, including the lead used for radiation shielding in radiotherapy. The bremsstrahlung radiation caused by the interaction between the electron beam and lead may reduce the accuracy of radiotherapy. To avoid the use of lead, a new material composed of tungsten and hydrogenated styrene-butadiene-styrene copolymer is studied with the Monte Carlo (MC) method and experiment in this paper. The component of the material is chosen after simulation with the MC method and the practical measurement is taken to validate the shielding ability of the material. The result shows that the shielding ability of the new material is good enough to fulfill the requirement for application in radiotherapy. Compared with lead alloy, the present new material is so flexible that can be easily customized into arbitrary shapes. Moreover, the material is environmentally friendly and can be recycled conveniently. Therefore, the material can be used as an effective lead substitute for shielding against electron beams in radiotherapy.

  18. A Case of Post-Radiotherapy Gastritis: Radiation Does Not Explain Everything

    Directory of Open Access Journals (Sweden)

    André Abrunhosa-Branquinho

    2014-01-01

    Full Text Available Hemorrhagic gastritis is a possible late toxicity outcome after radical radiotherapy but it is nowadays a very rare condition and most likely depends on other clinical factors. We report the case of a 77-year-old woman with a symptomatic solitary extramedullary intra-abdominal plasmacytoma and multiple gastric comorbidities, treated with external beam radiotherapy. Despite the good response to radiotherapy, the patient experienced multiple gastric bleeding a few months later, with the need of multiple treatments for its control. In this paper we will discuss in detail all aspects related to the different causes of hemorrhagic gastritis.

  19. Multi-energy imagers for a radiotherapy treatment environment

    Science.gov (United States)

    Antonuk, Larry E.; Liu, Langechuan; Liang, Albert K.; El-Mohri, Youcef; Zhao, Qihua; Koniczek, Martin; Jiang, Hao

    2015-03-01

    Over the last ~15 years, the central goal in external beam radiotherapy of maximizing dose to the tumor while minimizing dose to surrounding normal tissues has been greatly facilitated by the development and clinical implementation of many innovations. These include megavoltage active matrix flat-panel imagers (MV AMFPIs) designed to image the treatment beam, and separate kilovoltage (kV) AMFPIs and x-ray sources designed to provide high-contrast projection and cone-beam CT images in the treatment room. While these systems provide clinically valuable information, a variety of advantages would accrue through introduction of the capability to produce clinically useful, high quality imaging information at multiple energies (e.g., kV and MV) from a single detector along the treatment beam direction. One possible approach for achieving this goal involves substitution of the x-ray converters used in conventional MV AMFPIs with thick, segmented crystalline scintillators designed for dual-energy operation, coupled with the addition of x-ray imaging beams that contain a significant diagnostic component. A second approach involves introduction of a large area, monolithic array of photon counting pixels with multiple energy thresholds and event counters, which could provide multi-spectral views of the treatment beam with improved contrast. In this paper, the motivations behind, and the merits of each approach are described. In addition, prospects for such dual-energy imagers and photon counting array designs are discussed in the context of the radiotherapy environment.

  20. Long-term effects of radiotherapy for acromegaly on circulating prolactin

    Energy Technology Data Exchange (ETDEWEB)

    Ciccarelli, E.; Corsello, S.M.; Besser, G.M.; Wass, J.A.H. (Department of Endocrinology, St. Bartholomew' s Hospital, West Smithfield, London (UK)); Plowman, P.N.; Jones, A.E. (Department of Radiotherapy, St. Bartholomew' s Hospital, West Smithfield, London (UK)); Touzel, R.; Rees, L.H. (Department of Chemical Endocrinology, St. Bartholomew' s Hospital, West Smithfield, London (UK))

    1989-01-01

    In 61 acromegalic patients, serum PRL was assessed (off medical treatment) before and 2 to 12 (mean 6 p) years after external beam radiotherapy. Before radiotherapy elevated PRL levels were present in 22 of 35 males (63%) and 12 of 26 females (46%) and were above 1000 mU/l in 11 males and 5 females. When studied for up to 5 years after radiotherapy, 22 or 23 (96%) patients who had not had surgery and who had normal PRL preradiotherapy showed an increased PRL level and this was also seen in 17 or 27 (63%) who had hyperprolactinaemic initially. In contrast, 10 of 27 patients (37%) who had elevated pre-radiotherapy levels (all greater than 1000 mU/l) had a reduction in PRL values after radiotherapy. In all 11 patients who underwent surgery before radiotherapy, an increase in PRL was seen after radiotherapy. In the 21 patients followed for 10--12 years, the peak PRL value occurred 1--6 years after radiotherapy. After this, a progressive reduction of PRL to normal was seen. Normal levels were reached 4 to 10 years after radiotherapy. No correlation was found between pretreatment PRL values and final GH values in the whole group, nor between changes in PRL and the development of Impaired ACTH or TSH secretion. Thus, different patterns of PRL behaviour suggest that radiotherapy treatment may either produce hyperprolactinemia from mild hypothalamic damage or ablate PRL secreting cells if they were present in the tumour before treatment. These changes do not predict final GH results or the development of hypopituitarism after radiotherapy. (author).

  1. Electron energy and angular distributions in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Deasy, J.O.

    1992-01-01

    Electron energy and angular distributions and associated effects for radiotherapy accelerators and beta-ray ophthalmic applicators have been measured and modeled. Ophthalmic applicator extrapolation chamber calibration geometries were studied using Monte Carlo calculations and analytic methods. A large interface effect increases the surface dose by a factor of about 1.5 and makes very small gap width measurements necessary (0.1--0.2 mm). Dose deposition in tissue near the surface was simulated using the Monte Carlo technique. Charge collection in the extrapolation chamber was analytically modeled on the basis of ionized free electrons back-diffusing into the cathode, while taking into account attachment to O[sub 2] ions. Two small, portable, magnetic spectrometers for the measurement of clinical radiotherapy electron beams were constructed. One employs film as a spectrograph and is suitable for routine measurements; the second is a 90[degree] single-focusing spectrometer and uses fast pulse counting electrons and pulse-height analysis. Spectra were measured for the University of Louisville's Theratronics T20 and Philips SL25 linear accelerators. The T20 spectra were all Gaussian with energy widths of about 5%. The SL25 energy spectra were of varied shapes, with energy widths of 10--20%. Evidence of 3--7% shifts in the average energy of the SL25 beams was observed. Angular measurements were made which showed the Gaussian angular spread of the incident beam. The Monte Carlo code CYLTRAN and measured spectra were used to reconstruct depth dose curves. The peak energy structure only marginally affects the shape of the depth-dose curve, and some features of the depth-dose curves must be affected by incident straggled or widely-scattered electrons. In the absence of lower energy straggled electrons, the range parameters and the maximum dose gradient depend on the mean energy of the peak electrons.

  2. The role of image guidance in respiratory gated radiotherapy

    DEFF Research Database (Denmark)

    Korreman, Stine Sofia; Juhler-Nøttrup, Trine; Fredberg Persson, Gitte

    2008-01-01

    cycle, and thereby enable dose escalation and/or reduction of dose to organs at risk. Without adequate use of respiratory correlated image guidance on a regular basis, respiratory beam gating may however have a detrimental effect on target coverage. Image guidance of tumour respiratory motion...... is therefore of utmost importance for the safe introduction of respiratory gating. In this short overview, suitable image guidance strategies for respiratory gated radiotherapy are reviewed for two cancer sites; breast cancer and lung tumours....

  3. Plan optimization for stereotactic radiotherapy

    NARCIS (Netherlands)

    J.A. de Pooter (Jacobus Abraham)

    2008-01-01

    textabstractCancer is one of the leading causes of death in the world. Next to surgery and chemotherapy, radiotherapy is one of the most used treatment modalities for cancer. About 50% of the patients with cancer will be treated with radiotherapy during the management of their disease. In radiothera

  4. The Confluence of Radiotherapy & Immunotherapy

    Directory of Open Access Journals (Sweden)

    Ralph Robert Weichselbaum

    2012-10-01

    Full Text Available Radiotherapy has been considered a local modality and outcomes have emphasized local and regional control of tumors. Recent data suggests that radiotherapy may activate the immune system and the combination of radiation therapy and immune therapies may have the potential to improve both local and distant control of tumor deposits. Below we review principals underlying the concepts of combining both modalities.

  5. Intraoperative radiotherapy in the theatre room with electron beams: technical and dosimetric description of Sordina LIAC accelerator; Radioterapia intraoperatoria en quirofano con haces de electrones: descripcion tecnica y dosimetrica del acelerador dedicado Sordina LIAC

    Energy Technology Data Exchange (ETDEWEB)

    Sendon del Rio, J. R.; Ayala Lazaro, R.; Gomez Cores, S.; Garcia Hernandez, M. J.; Polo Cezon, R.; Jimenez Rojas, R.; Lopez Bote, M. A.

    2015-05-01

    n this work we show our experience during the commissioning of a mobile electron-beam accelerator dedicated to intraoperative radiation therapy in the theatre room. The linac is a Sordina LIAC 12 MeV model with a hard-docking applicator system. We describe the linac, the measurement methods and the specific dosimetry. The dosimetric behavior is also discussed. Differences with other applicator systems can be explained from the particular head design of the linac. (Author)

  6. Radiotherapy of benign diseases

    Energy Technology Data Exchange (ETDEWEB)

    Haase, W.

    1982-10-11

    Still today radiotherapy is of decisive relevance for several benign diseases. The following ones are briefly described in this introductory article: 1. Certain inflammatory and degenerative diseases as furuncles in the face, acute thrombophlebitis, recurrent pseudoriparous abscesses, degenerative skeletal diseases, cervical syndrome and others; 2. rheumatic joint diseases; 3. Bechterew's disease; 4. primary presenile osteoporosis; 5. syringomyelia; 6. endocrine ophthalmopathy; 7. hypertrophic processes of the connective tissue; 8. hemangiomas. A detailed discussion and a profit-risk analysis is provided in the individual chapters of the magazine.

  7. 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.

  8. From image-guided radiotherapy to dose-guided radiotherapy; De la radiotherapie guidee par l'image a la radiotherapie guidee par la dose

    Energy Technology Data Exchange (ETDEWEB)

    Cazoulat, G.; Lesaunier, M.; Simon, A.; Haigron, P.; Acosta, O. [Inserm, U642, 35000 Rennes (France); LTSI, universite de Rennes-1, 35000 Rennes (France); Louvel, G.; Chajon, E.; Leseur, J. [Centre Eugene-Marquis, rue de La-Bataille-Flandres-Dunkerque, CS 44229, 35042 Rennes cedex (France); Lafond, C.; De Crevoisier, R. [Inserm, U642, 35000 Rennes (France); LTSI, universite de Rennes-1, 35000 Rennes (France); Centre Eugene-Marquis, rue de La-Bataille-Flandres-Dunkerque, CS 44229, 35042 Rennes cedex (France)

    2011-12-15

    Purpose. - In case of tumour displacement, image-guided radiotherapy (IGRT) based on the use of cone beam CT (tomographie conique) allows replacing the tumour under the accelerator by rigid registration. Anatomical deformations require however re-planning, involving an estimation of the cumulative dose, session after session. This is the objective of this study. Patients and methods. - Two examples of arc-intensity modulated radiotherapy are presented: a case of prostate cancer (total dose = 80 Gy) with tomographie conique (daily prostate registration) and one head and neck cancer (70 Gy). For the head and neck cancer, the patient had a weekly scanner allowing a dose distribution calculation. The cumulative dose was calculated per voxel on the planning CT after deformation of the dose distribution (with trilinear interpolation) following the transformation given by a non-rigid registration step (Demons registration method) from: either the tomographie conique (prostate), or the weekly CT. The cumulative dose was eventually compared with the planned dose. Results. - In cases of prostate irradiation, the 'cumulative' dose corresponded to the planned dose to the prostate. At the last week of irradiation, it was above the planned dose for the rectum and bladder. The volume of rectal wall receiving more than 50 Gy (V50) was 20% at the planning and 26% at the end of treatment, increasing the risk of rectal toxicity (NTCP) of 14%. For the bladder wall, V50 were 73% and 82%, respectively. In head and neck, the 'cumulative' dose to the parotid exceeded the planned dose (mean dose increasing from 46 Gy to 54 Gy) from the 5. week of irradiation on, suggesting the need for re-planning within the first 5 weeks of radiotherapy. Conclusion. - The deformable registration estimates the cumulative dose delivered in the different anatomical structures. Validation on digital and physical phantoms is however required before clinical evaluation. (authors)

  9. Project and construction of energy degrading and scattering plates for electron beam radiotherapy for skin diseases; Projeto e construcao de placas espalhadoras e degradadoras de energia para uso em radioterapia com feixes de eletrons para doencas de pele

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel Paiva

    2010-07-01

    There are many radiosensitive epidermotropics diseases such as mycosis fungo-ids and the syndrome of Sezary, coetaneous neoplasics originated from type T lymphocytes. Several studies indicate the eradication of the disease when treated with linear accelerators emitting electron beams with energies between 4 to 10 MeV. However, this treatment technique presents innumerable technical challenges since the disease in general reaches all patient's body, becoming necessary not only a very large field size radiation beam, but also deliver superficial doses limited to the skin depth. To reach the uniformity in the dose distribution, many techniques had already been developed. Based on these previous studies and guided by the report no. 23 of the American Association of Physicists in Medi-cine (AAPM), the present study developed an energy scattering and degrading plates and made dosimetry (computational and experimental), supplying subsidies for a future installation of Total Skin Electron Therapy (TSET) at the Servico de Radioterapia do Hospital das Clinicas de Sao Paulo. As part of the plates design, first of all, the energy spectrum of the 6 MeV electron beam of the VARIAN 2100C accelerator was reconstructed through Monte Carlo simulations using the MCNP4C code and based on experimental data. Once the spectrum is built, several materials were analyzed for the plates design based on radial and axial dose distribution, production of rays-x and dose attenuation. The simulation results were validated by experimental measurements in order to obtain a large field of radiation with 200 cm x 80 cm that meets the specifications of the AAPM protocol. (author)

  10. Uncertainties estimation in the ultrasound CMS-I beam image prostate localization; Estimacion de las incertidumbres en el sistema locadizador de prostata por ultrasonidos CMS I-Beam

    Energy Technology Data Exchange (ETDEWEB)

    Sanz Freire, C. J.; Martin Rincon, C.; Marques Fraguela, E.; Prezado Alonso, Y.; Montes Fuentes, C.; Fernandez Bordes, M.

    2006-07-01

    Organ motion is an issue of major concern when dose escalation techniques in radiotherapy such as IMRT are considered. Patient and organ motion can be better account for by means of Image-Guided Radiotherapy (IGRT), allowing for a reduction of margins to the CTV. Ultrasound images have been used for prostate localization. The aim of the present work is to evaluate the uncertainties of the newly developed ultrasound-based system CMS I-BEAM for daily prostate localization in radiotherapy. (Author)

  11. Development of heavy-ion radiotherapy technology with HIMAC

    Science.gov (United States)

    Noda, Koji

    2016-09-01

    Since 1994, HIMAC has carried out clinical studies and treatments for more than 9000 cancer patients with carbon-ion beams. During the first decade of the HIMAC study, a single beam-wobbling method, adopted as the HIMAC beam-delivery technique, was improved for treatments of moving tumors and for obtaining more conformal dose distribution. During the second decade, a pencil-beam 3D scanning method has been developed toward an “adaptive cancer treatment” for treatments of both static and moving tumors. A new treatment research facility was constructed with HIMAC in order to verify the developed 3D scanning technology through a clinical study that has been successfully conducted since 2011. As the next stage, a compact heavy-ion rotating gantry with a superconducting technology has been developed for the more accurate and shorter-course treatments. The twenty-year development of the heavy-ion radiotherapy technologies including accelerator technologies with HIMAC is reviewed.

  12. Radiotherapy in prostate cancer. Innovative techniques and current controversies

    Energy Technology Data Exchange (ETDEWEB)

    Geinitz, Hans [Krankenhaus der Barmherzigen Schwestern, Linz (Austria). Dept. of Radiation Oncology; Linz Univ. (Austria). Medical Faculty; Roach, Mack III [California Univ., San Francisco, CA (United States). Dept. of Radiation Oncology; Van As, Nicholas (ed.) [The Institute of Cancer Research, Sutton Surrey (United Kingdom)

    2015-04-01

    Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

  13. Target margins in radiotherapy of prostate cancer.

    Science.gov (United States)

    Yartsev, Slav; Bauman, Glenn

    2016-11-01

    We reviewed the literature on the use of margins in radiotherapy of patients with prostate cancer, focusing on different options for image guidance (IG) and technical issues. The search in PubMed database was limited to include studies that involved external beam radiotherapy of the intact prostate. Post-prostatectomy studies, brachytherapy and particle therapy were excluded. Each article was characterized according to the IG strategy used: positioning on external marks using room lasers, bone anatomy and soft tissue match, usage of fiducial markers, electromagnetic tracking and adapted delivery. A lack of uniformity in margin selection among institutions was evident from the review. In general, introduction of pre- and in-treatment IG was associated with smaller planning target volume (PTV) margins, but there was a lack of definitive experimental/clinical studies providing robust information on selection of exact PTV values. In addition, there is a lack of comparative research regarding the cost-benefit ratio of the different strategies: insertion of fiducial markers or electromagnetic transponders facilitates prostate gland localization but at a price of invasive procedure; frequent pre-treatment imaging increases patient in-room time, dose and labour; online plan adaptation should improve radiation delivery accuracy but requires fast and precise computation. Finally, optimal protocols for quality assurance procedures need to be established.

  14. SU-E-T-304: Dosimetric Comparison of Cavernous Sinus Tumors: Heterogeneity Corrected Pencil Beam (PB-Hete) Vs. X-Ray Voxel Monte Carlo (XVMC) Algorithms for Stereotactic Radiotherapy (SRT)

    Energy Technology Data Exchange (ETDEWEB)

    Pokhrel, D; Sood, S; Badkul, R; Jiang, H; Saleh, H; Wang, F [University of Kansas Hospital, Kansas City, KS (United States)

    2015-06-15

    Purpose: To compare dose distributions calculated using PB-hete vs. XVMC algorithms for SRT treatments of cavernous sinus tumors. Methods: Using PB-hete SRT, five patients with cavernous sinus tumors received the prescription dose of 25 Gy in 5 fractions for planning target volume PTV(V100%)=95%. Gross tumor volume (GTV) and organs at risk (OARs) were delineated on T1/T2 MRI-CT-fused images. PTV (range 2.1–84.3cc, mean=21.7cc) was generated using a 5mm uniform-margin around GTV. PB-hete SRT plans included a combination of non-coplanar conformal arcs/static beams delivered by Novalis-TX consisting of HD-MLCs and a 6MV-SRS(1000 MU/min) beam. Plans were re-optimized using XVMC algorithm with identical beam geometry and MLC positions. Comparison of plan specific PTV(V99%), maximal, mean, isocenter doses, and total monitor units(MUs) were evaluated. Maximal dose to OARs such as brainstem, optic-pathway, spinal cord, and lenses as well as normal tissue volume receiving 12Gy(V12) were compared between two algorithms. All analysis was performed using two-tailed paired t-tests of an upper-bound p-value of <0.05. Results: Using either algorithm, no dosimetrically significant differences in PTV coverage (PTVV99%,maximal, mean, isocenter doses) and total number of MUs were observed (all p-values >0.05, mean ratios within 2%). However, maximal doses to optic-chiasm and nerves were significantly under-predicted using PB-hete (p=0.04). Maximal brainstem, spinal cord, lens dose and V12 were all comparable between two algorithms, with exception of one patient with the largest PTV who exhibited 11% higher V12 with XVMC. Conclusion: Unlike lung tumors, XVMC and PB-hete treatment plans provided similar PTV coverage for cavernous sinus tumors. Majority of OARs doses were comparable between two algorithms, except for small structures such as optic chiasm/nerves which could potentially receive higher doses when using XVMC algorithm. Special attention may need to be paid on a case

  15. Experimental determination of field factors (\\Omega _{{{Q}_{\\text{clin}}},{{Q}_{\\text{msr}}}}^{{{f}_{\\text{clin}}},{{f}_{\\text{msr}}}} ) for small radiotherapy beams using the daisy chain correction method

    Science.gov (United States)

    Lárraga-Gutiérrez, José Manuel

    2015-08-01

    Recently, Alfonso et al proposed a new formalism for the dosimetry of small and non-standard fields. The proposed new formalism is strongly based on the calculation of detector-specific beam correction factors by Monte Carlo simulation methods, which accounts for the difference in the response of the detector between the small and the machine specific reference field. The correct calculation of the detector-specific beam correction factors demands an accurate knowledge of the linear accelerator, detector geometry and composition materials. The present work shows that the field factors in water may be determined experimentally using the daisy chain correction method down to a field size of 1 cm  ×  1 cm for a specific set of detectors. The detectors studied were: three mini-ionization chambers (PTW-31014, PTW-31006, IBA-CC01), three silicon-based diodes (PTW-60018, IBA-SFD and IBA-PFD) and one synthetic diamond detector (PTW-60019). Monte Carlo simulations and experimental measurements were performed for a 6 MV photon beam at 10 cm depth in water with a source-to-axis distance of 100 cm. The results show that the differences between the experimental and Monte Carlo calculated field factors are less than 0.5%—with the exception of the IBA-PFD—for field sizes between 1.5 cm  ×  1.5 cm and 5 cm  ×  5 cm. For the 1 cm  ×  1 cm field size, the differences are within 2%. By using the daisy chain correction method, it is possible to determine measured field factors in water. The results suggest that the daisy chain correction method is not suitable for measurements performed with the IBA-PFD detector. The latter is due to the presence of tungsten powder in the detector encapsulation material. The use of Monte Carlo calculated k{{Q\\text{clin}},{{Q}\\text{msr}}}{{f\\text{clin}},{{f}\\text{msr}}} is encouraged for field sizes less than or equal to 1 cm  ×  1 cm for the dosimeters used in this work.

  16. Advances in conformal radiotherapy using Monte Carlo Code to design new IMRT and IORT accelerators and interpret CT numbers

    CERN Document Server

    Wysocka-Rabin, A

    2013-01-01

    The introductory chapter of this monograph, which follows this Preface, provides an overview of radiotherapy and treatment planning. The main chapters that follow describe in detail three significant aspects of radiotherapy on which the author has focused her research efforts. Chapter 2 presents studies the author worked on at the German National Cancer Institute (DKFZ) in Heidelberg. These studies applied the Monte Carlo technique to investigate the feasibility of performing Intensity Modulated Radiotherapy (IMRT) by scanning with a narrow photon beam. This approach represents an alternative to techniques that generate beam modulation by absorption, such as MLC, individually-manufactured compensators, and special tomotherapy modulators. The technical realization of this concept required investigation of the influence of various design parameters on the final small photon beam. The photon beam to be scanned should have a diameter of approximately 5 mm at Source Surface Distance (SSD) distance, and the penumbr...

  17. [New techniques and potential benefits for radiotherapy of lung cancer].

    Science.gov (United States)

    Lefebvre, L; Doré, M; Giraud, P

    2014-10-01

    Radiotherapy is used for inoperable lung cancers, sometimes in association with chemotherapy. Outcomes of conventional radiotherapy are disappointing. New techniques improve adaptation to tumour volume, decrease normal tissue irradiation and lead to increasing tumour dose with the opportunity for improved survival. With intensity-modulated radiation therapy, isodoses can conform to complex volumes. It is widely used and seems to be indicated in locally advanced stages. Its dosimetric improvements have been demonstrated but outcomes are still heterogeneous. Stereotactic radiotherapy allows treatment of small volumes with many narrow beams. Dedicated devices or appropriate equipment on classical devices are needed. In early stages, its efficacy is comparable to surgery with an acceptable toxicity. Endobronchial brachytherapy could be used for early stages with specific criteria. Hadrontherapy is still experimental regarding lung cancer. Hadrons have physical properties leading to very accurate dose distribution. In the rare published studies, toxicities are roughly lower than others techniques but for early stages its effectiveness is not better than stereotactic radiotherapy. These techniques are optimized by metabolic imaging which precisely defines the target volume and assesses the therapeutic response; image-guided radiation therapy which allows a more accurate patient set up and by respiratory tracking or gating which takes account of tumour respiratory motions.

  18. Stereotactic radiotherapy for vestibular schwannoma

    DEFF Research Database (Denmark)

    Muzevic, Dario; Legcevic, Jelena; Splavski, Bruno;

    2014-01-01

    ; Web of Science; CAB Abstracts; ISRCTN and additional sources for published and unpublished trials. The date of the search was 24 July 2014. SELECTION CRITERIA: Randomised controlled trials (RCTs) exploring the efficacy of stereotactic radiotherapy compared with observation alone, microsurgical...

  19. Electron Energy and Angular Distributions in Radiotherapy.

    Science.gov (United States)

    Deasy, Joseph Owen

    1992-01-01

    Electron energy and angular distributions and associated effects for radiotherapy accelerators and beta -ray ophthalmic applicators have been measured and modeled. Ophthalmic applicator extrapolation chamber calibration geometries were studied using Monte Carlo calculations and analytic methods. A large interface effect increases the surface dose by a factor of about 1.5 and makes very small gap width measurements necessary (0.1-0.2 mm). Dose deposition in tissue near the surface was simulated using the Monte Carlo technique. Charge collection in the extrapolation chamber was analytically modeled on the basis of ionized free electrons back-diffusing into the cathode, while taking into account attachment to O_2 ions. Previous models underpredict the charge loss, mainly because they assume that all the charge carriers are ions. Two small, portable, magnetic spectrometers for the measurement of clinical radiotherapy electron beams were constructed. One employs film as a spectrograph and is suitable for routine measurements; the second is a 90^circ single-focusing spectrometer and uses fast pulse counting electronics and pulse-height analysis. Tests with monoenergetic electron beams at the National Research Council of Canada's electron linear accelerator showed that the system is free from spectral distortion and verified the spectrometers' energy calibrations. Spectra were measured for the University of Louisville's Theratronics T20 and Philips SL25 linear accelerators. The T20 spectra were all nearly Gaussian in shape with energy widths of about 5%. The SL25 energy spectra were of varied shapes, with energy widths of 10-20%. Evidence of 3-7% shifts in the average energy of the SL25 beams was observed. Angular measurements were made which showed the Gaussian angular spread of the incident beam. The Monte Carlo code CYLTRAN and measured spectra were used to reconstruct depth dose curves. Comparisons with measured depth dose curves show that the peak energy structure

  20. The six-bank multi-leaf system : A large field size, high resolution collimator for advanced

    NARCIS (Netherlands)

    Topolnjak, R.

    2006-01-01

    A linear accelerator (linac) is the most commonly used device for treatment of patients with cancer in external beam radiotherapy (EBRT). The Linac delivers a high-energy ionizing radiation (photons or electrons) to the region of the patient's tumor. The absorption of radiation in the treated area d

  1. Radioprotectors in Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Nair, C.K.K. [Bhabha Atomic Research Centre, Mumbai (India); Parida, D.K.; Nomura, Taisei

    2001-03-01

    This review article focuses on clinically relevant radioprotectors and their mechanisms of radioprotection. Radiotherapy is the most common modality of human cancer therapy. Obtaining optimal results requires a judicious balance between the total dose of radiotherapy delivered and the threshold limit of critical surrounding normal tissues, and the normal tissues need to be protected against radiation injury to obtain better tumor control by using a higher dose. For this reason, radiation-protective agents play an important role in clinical radiotherapy. Radiation-protective agents can be classified into three groups: radioprotectors, adaptogens, and absorbents. The first group generally consists of sulfhydryl compounds and other antioxidants. They include several myelo-, entero-, and cerebro-protectors. Adaptogens act as promotors of radioresistance. They are natural protectors that offer chemical protection against low levels of ionizing radiation. Absorbents protect organs from internal radiation and chemicals. They include drugs that prevent incorporation of radioiodine by the thyroid gland and absorption of radionuclides. This article thoroughly describes the properties, mechanisms of action, and perspectives on clinical application of the following categories of radioprotectors: sulfhydryl compounds (e.g., cysteine, cysteamine, glutathione, AET, WR 2127, and other WR-compounds), antioxidants (e.g., tempace, Hoechst 33342, vitamin A, E, and C, TMG, melatonin), angiotensin-converting enzyme (ACE) inhibitors (e.g., captopril, elanopril, penicillamine, pentoxifylline, L-158, 809), cytoprotec