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Sample records for dynamic intensity-modulated radiotherapy

  1. Random and systematic beam modulator errors in dynamic intensity modulated radiotherapy

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    Parsai, Homayon [Department of Radiation Oncology, University of Washington, Box 356043, Seattle, WA 98195 (United States); Cho, Paul S [Department of Radiation Oncology, University of Washington, Box 356043, Seattle, WA 98195 (United States); Phillips, Mark H [Department of Radiation Oncology, University of Washington, Box 356043, Seattle, WA 98195 (United States); Giansiracusa, Robert S [Department of Radiation Oncology, University of Washington, Box 356043, Seattle, WA 98195 (United States); Axen, David [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada)

    2003-05-07

    This paper reports on the dosimetric effects of random and systematic modulator errors in delivery of dynamic intensity modulated beams. A sliding-widow type delivery that utilizes a combination of multileaf collimators (MLCs) and backup diaphragms was examined. Gaussian functions with standard deviations ranging from 0.5 to 1.5 mm were used to simulate random positioning errors. A clinical example involving a clival meningioma was chosen with optic chiasm and brain stem as limiting critical structures in the vicinity of the tumour. Dose calculations for different modulator fluctuations were performed, and a quantitative analysis was carried out based on cumulative and differential dose volume histograms for the gross target volume and surrounding critical structures. The study indicated that random modulator errors have a strong tendency to reduce minimum target dose and homogeneity. Furthermore, it was shown that random perturbation of both MLCs and backup diaphragms in the order of {sigma} = 1 mm can lead to 5% errors in prescribed dose. In comparison, when MLCs or backup diaphragms alone was perturbed, the system was more robust and modulator errors of at least {sigma} = 1.5 mm were required to cause dose discrepancies greater than 5%. For systematic perturbation, even errors in the order of {+-}0.5 mm were shown to result in significant dosimetric deviations.

  2. Cardiac Exposure in the Dynamic Conformal Arc Therapy, Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy of Lung Cancer.

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    Xin Ming

    Full Text Available To retrospectively evaluate the cardiac exposure in three cohorts of lung cancer patients treated with dynamic conformal arc therapy (DCAT, intensity-modulated radiotherapy (IMRT, or volumetric modulated arc therapy (VMAT at our institution in the past seven years.A total of 140 lung cancer patients were included in this institutional review board approved study: 25 treated with DCAT, 70 with IMRT and 45 with VMAT. All plans were generated in a same commercial treatment planning system and have been clinically accepted and delivered. The dose distribution to the heart and the effects of tumor laterality, the irradiated heart volume and the beam-to-heart distance on the cardiac exposure were investigated.The mean dose to the heart among all 140 plans was 4.5 Gy. Specifically, the heart received on average 2.3, 5.2 and 4.6 Gy in the DCAT, IMRT and VMAT plans, respectively. The mean heart doses for the left and right lung tumors were 4.1 and 4.8 Gy, respectively. No patients died with evidence of cardiac disease. Three patients (2% with preexisting cardiac condition developed cardiac disease after treatment. Furthermore, the cardiac exposure was found to increase linearly with the irradiated heart volume while decreasing exponentially with the beam-to-heart distance.Compared to old technologies for lung cancer treatment, modern radiotherapy treatment modalities demonstrated better heart sparing. But the heart dose in lung cancer radiotherapy is still higher than that in the radiotherapy of breast cancer and Hodgkin's disease where cardiac complications have been extensively studied. With strong correlations of mean heart dose with beam-to-heart distance and irradiated heart volume, cautions should be exercised to avoid long-term cardiac toxicity in the lung cancer patients undergoing radiotherapy.

  3. Intensity-Modulated Radiotherapy for Pancreatic Adenocarcinoma

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    Abelson, Jonathan A.; Murphy, James D.; Minn, Ann Yuriko; Chung, Melody [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Fisher, George A.; Ford, James M.; Kunz, Pamela [Department of Medical Oncology, Stanford University, Stanford, CA (United States); Norton, Jeffrey A.; Visser, Brendan C.; Poultsides, George A. [Department of Surgical Oncology, Stanford University, Stanford, CA (United States); Koong, Albert C. [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Chang, Daniel T., E-mail: dtchang@stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, CA (United States)

    2012-03-15

    Purpose: To report the outcomes and toxicities in patients treated with intensity-modulated radiotherapy (IMRT) for pancreatic adenocarcinoma. Methods and Materials: Forty-seven patients with pancreatic adenocarcinoma were treated with IMRT between 2003 and 2008. Of these 47 patients, 29 were treated adjuvantly and 18 definitively. All received concurrent 5-fluorouracil chemotherapy. The treatment plans were optimized such that 95% of the planning target volume received the prescription dose. The median delivered dose for the adjuvant and definitive patients was 50.4 and 54.0 Gy, respectively. Results: The median age at diagnosis was 63.9 years. For adjuvant patients, the 1- and 2-year overall survival rate was 79% and 40%, respectively. The 1- and 2-year recurrence-free survival rate was 58% and 17%, respectively. The local-regional control rate at 1 and 2 years was 92% and 80%, respectively. For definitive patients, the 1-year overall survival, recurrence-free survival, and local-regional control rate was 24%, 16%, and 64%, respectively. Four patients developed Grade 3 or greater acute toxicity (9%) and four developed Grade 3 late toxicity (9%). Conclusions: Survival for patients with pancreatic cancer remains poor. A small percentage of adjuvant patients have durable disease control, and with improved therapies, this proportion will increase. Systemic therapy offers the greatest opportunity. The present results have demonstrated that IMRT is well tolerated. Compared with those who received three-dimensional conformal radiotherapy in previously reported prospective clinical trials, patients with pancreatic adenocarcinoma treated with IMRT in our series had improved acute toxicity.

  4. Single arc volumetric-modulated arc therapy is sufficient for nasopharyngeal carcinoma: a dosimetric comparison with dual arc VMAT and dynamic MLC and step-and-shoot intensity-modulated radiotherapy

    OpenAIRE

    NING, ZHONG-HUA; Mu, Jin-Ming; Jin, Jian-Xue; Li, Xiao-Dong; LI, QI-LIN; GU, WEN-DONG; Huang, Jin; Han, Yang; PEI, HONG-LEI

    2013-01-01

    Background The performance of single arc VMAT (VMAT1) for nasopharyngeal carcinoma (NPC) on the Axesse linac has not been well described in previous studies. The purpose of this study is to assess the feasibility of VMAT1 for NPC by comparing the dosimetry, delivery efficiency, and accuracy with dual arc VMAT (VMAT2), dynamic MLC intensity-modulated radiotherapy (dIMRT), and step-and-shoot intensity-modulated radiotherapy (ssIMRT). Methods Twenty consecutive patients with non-metastatic NPC w...

  5. Commissioning and quality assurance for intensity modulated radiotherapy with dynamic multileaf collimator: experience of the Pontificia Universidad Católica de Chile.

    Science.gov (United States)

    Venencia, Carlos Daniel; Besa, Pelayo

    2004-01-01

    The objective of this paper is to present our experience in the commissioning and quality assurance (QA) for intensity modulated radiotherapy (IMRT) using dynamic multileaf collimator (dMLC), sliding window technique. Using Varian equipment solution, the connectivity and operation between all IMRT chain components was checked. Then the following test were done: stability of leaf positioning and leaf speed, sensitivity to treatment interruptions (acceleration and deceleration), evaluation of standard field patterns, stability of dMLC output, segmental dose accuracy check, average leaf transmission, dosimetric leaf separation, effects of lateral disequilibrium between adjacent leaves in dose profiles and multiple carriage field verification. Standard patterns were generated for verification: uniform field, pyramid, hole, wedge, peaks and chair. Weekly QA Protocol include: sweeping gap output, Garden Fence Test (narrow bands, 2 mm wide, of exposure spaced at 2-cm intervals) and segmental dose accuracy check. Monthly QA include: sweeping gap output at multiple gantry and collimator angle, sweeping gap output off-axis, Picket Fence Test (eight consecutive movements of a 5-cm wide rectangular field spaced at 5-cm intervals), stability of leaf speed and leaf motor current test (PWM test). Patient QA procedure consists of an absolute dose measurement for all treatments fields in the treatment condition, analysis of actual leaf position versus planned leaf position (dynalog files) for each treatment field, film relative dose determination for each field, film relative dose determination for the plan (all treatment fields) in two axial planes and patient positioning verification with orthogonal films. The tests performed showed acceptable result. After more than one year of IMRT treatment the routine QA machine checks confirm the precision and stability of the IMRT system.

  6. Dose profile analysis of small fields in intensity modulated radiotherapy

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    Medel B, E. [IMSS, Centro Medico Nacional Manuel Avila Camacho, Calle 2 Nte. 2004, Barrio de San Francisco, 72090 Puebla, Pue. (Mexico); Tejeda M, G.; Romero S, K., E-mail: romsakaren@gmail.com [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico Matematicas, Av. San Claudio y 18 Sur, Ciudad Universitaria, 72570 Puebla, Pue.(Mexico)

    2015-10-15

    Full text: Small field dosimetry is getting a very important worldwide task nowadays. The use of fields of few centimeters is more common with the introduction of sophisticated techniques of radiation therapy, as Intensity Modulated Radiotherapy (IMRT). In our country the implementation of such techniques is just getting started and whit it the need of baseline data acquisition. The dosimetry under small field conditions represents a challenge for the physicists community. In this work, a dose profile analysis was done, using various types of dosimeters for further comparisons. This analysis includes the study of quality parameters as flatness, symmetry, penumbra, and other in-axis measurements. (Author)

  7. Effects of intensity-modulated radiotherapy on human oral microflora.

    Science.gov (United States)

    Shao, Zi-Yang; Tang, Zi-Sheng; Yan, Chao; Jiang, Yun-Tao; Ma, Rui; Liu, Zheng; Huang, Zheng-Wei

    2011-01-01

    This study aimed to evaluate changes in the biodiversity of the oral microflora of patients with head and neck cancer treated with postoperative intensity-modulated radiotherapy (IMRT) or conventional radiotherapy (CRT). Pooled dental plaque samples were collected during the radiation treatment from patients receiving IMRT (n = 13) and CRT (n = 12). Denaturing gradient gel electrophoresis (DGGE) was used to analyze the temporal variation of these plaque samples. The stimulated and unstimulated salivary flow rates were also compared between IMRT and CRT patients. Reductions in the severity of hyposalivation were observed in IMRT patients compared with CRT patients. We also observed that the temporal stability of the oral ecosystem was significantly higher in the IMRT group (69.96 ± 7.82%) than in the CRT group (51.98 ± 10.45%) (P oral ecosystem than CRT.

  8. Benchmarking Dosimetric Quality Assessment of Prostate Intensity-Modulated Radiotherapy

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    Senthi, Sashendra, E-mail: sasha.senthi@petermac.org [Division of Radiation Oncology, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Gill, Suki S. [Division of Radiation Oncology, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Haworth, Annette; Kron, Tomas; Cramb, Jim [Department of Physical Sciences, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Rolfo, Aldo [Radiation Therapy Services, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Thomas, Jessica [Biostatistics and Clinical Trials, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Duchesne, Gillian M. [Division of Radiation Oncology, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia); Hamilton, Christopher H.; Joon, Daryl Lim [Radiation Oncology Department, Austin Repatriation Hospital, Heidelberg, VIC (Australia); Bowden, Patrick [Radiation Oncology Department, Tattersall' s Cancer Center, East Melbourne, VIC (Australia); Foroudi, Farshad [Division of Radiation Oncology, Peter MacCallum Cancer Center, East Melbourne, VIC (Australia)

    2012-02-01

    Purpose: To benchmark the dosimetric quality assessment of prostate intensity-modulated radiotherapy and determine whether the quality is influenced by disease or treatment factors. Patients and Methods: We retrospectively analyzed the data from 155 consecutive men treated radically for prostate cancer using intensity-modulated radiotherapy to 78 Gy between January 2007 and March 2009 across six radiotherapy treatment centers. The plan quality was determined by the measures of coverage, homogeneity, and conformity. Tumor coverage was measured using the planning target volume (PTV) receiving 95% and 100% of the prescribed dose (V{sub 95%} and V{sub 100%}, respectively) and the clinical target volume (CTV) receiving 95% and 100% of the prescribed dose. Homogeneity was measured using the sigma index of the PTV and CTV. Conformity was measured using the lesion coverage factor, healthy tissue conformity index, and the conformity number. Multivariate regression models were created to determine the relationship between these and T stage, risk status, androgen deprivation therapy use, treatment center, planning system, and treatment date. Results: The largest discriminatory measurements of coverage, homogeneity, and conformity were the PTV V{sub 95%}, PTV sigma index, and conformity number. The mean PTV V{sub 95%} was 92.5% (95% confidence interval, 91.3-93.7%). The mean PTV sigma index was 2.10 Gy (95% confidence interval, 1.90-2.20). The mean conformity number was 0.78 (95% confidence interval, 0.76-0.79). The treatment center independently influenced the coverage, homogeneity, and conformity (all p < .0001). The planning system independently influenced homogeneity (p = .038) and conformity (p = .021). The treatment date independently influenced the PTV V{sub 95%} only, with it being better at the start (p = .013). Risk status, T stage, and the use of androgen deprivation therapy did not influence any aspect of plan quality. Conclusion: Our study has benchmarked measures

  9. Prostate Bed Motion During Intensity-Modulated Radiotherapy Treatment

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    Klayton, Tracy; Price, Robert; Buyyounouski, Mark K.; Sobczak, Mark [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Greenberg, Richard [Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Li, Jinsheng; Keller, Lanea; Sopka, Dennis [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Kutikov, Alexander [Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Horwitz, Eric M., E-mail: eric.horwitz@fccc.edu [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States)

    2012-09-01

    Purpose: Conformal radiation therapy in the postprostatectomy setting requires accurate setup and localization of the prostatic fossa. In this series, we report prostate bed localization and motion characteristics, using data collected from implanted radiofrequency transponders. Methods and Materials: The Calypso four-dimensional localization system uses three implanted radiofrequency transponders for daily target localization and real-time tracking throughout a course of radiation therapy. We reviewed the localization and tracking reports for 20 patients who received ultrasonography-guided placement of Calypso transponders within the prostate bed prior to a course of intensity-modulated radiation therapy at Fox Chase Cancer Center. Results: At localization, prostate bed displacement relative to bony anatomy exceeded 5 mm in 9% of fractions in the anterior-posterior (A-P) direction and 21% of fractions in the superior-inferior (S-I) direction. The three-dimensional vector length from skin marks to Calypso alignment exceeded 1 cm in 24% of all 652 fractions with available setup data. During treatment, the target exceeded the 5-mm tracking limit for at least 30 sec in 11% of all fractions, generally in the A-P or S-I direction. In the A-P direction, target motion was twice as likely to move posteriorly, toward the rectum, than anteriorly. Fifteen percent of all treatments were interrupted for repositioning, and 70% of patients were repositioned at least once during their treatment course. Conclusion: Set-up errors and motion of the prostatic fossa during radiotherapy are nontrivial, leading to potential undertreatment of target and excess normal tissue toxicity if not taken into account during treatment planning. Localization and real-time tracking of the prostate bed via implanted Calypso transponders can be used to improve the accuracy of plan delivery.

  10. SU-E-T-409: Intensity Modulated Robotic Radiotherapy

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    Wang, B; Jin, L; Li, J; Chen, L; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Fan, J [Fox Chase Cancer Center, Philadelphia, PA (United States); Virtua Fox Chase Cancer Center, Voorhees, NJ (United States); Zhang, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Qiqihar Medical University, Qiqihar (China)

    2014-06-01

    Purpose: As compared with the IRIS-based models, the MLC-based CyberKnife system allows more efficient treatment delivery due to its improved coverage of large lesions and intensity modulation. The treatment delivery efficiency is mainly determined by the number of selected nodes. This study aimed to demonstrate that relatively small sets of optimally selected nodes could produce high-quality plans. Methods: The full body path of the CyberKnife system consists of 110 nodes, from which we selected various sets for 4 prostate cancer cases using our in-house beamselection software. With the selected nodes we generated IMRT plans using our in-house beamlet-based inverse-planning optimization program. We also produced IMRT plans using the MultiPlan treatment planning system (version 5.0) for the same cases. Furthermore, the nodes selected by MultiPlan were used to produce plans with our own optimization software so that we could compare the quality of the selected sets of nodes. Results: Our beam-selection program selected one node-set for each case, with the number of nodes ranging from 23 to 34. The IMRT plans based on the selected nodes and our in-house optimization program showed adequate target coverage, with favorable critical structure sparing for the cases investigated. Compared with the plans using the nodes selected by MultiPlan, the plans generated with our selected beams provided superior rectum/bladder sparing for 75% of the cases. The plans produced by MultiPlan with various numbers of nodes also suggested that the plan quality was not compromised significantly when the number of nodes was reduced. Conclusion: Our preliminary results showed that with beamletbased planning optimization, one could produce high-quality plans with an optimal set of nodes for MLC-based robotic radiotherapy. Furthermore, our beam-selection strategy could help further improve critical structure sparing.

  11. Adjuvant radiotherapy for gallbladder cancer: A dosimetric comparison of conformal radiotherapy and intensity-modulated radiotherapy

    Institute of Scientific and Technical Information of China (English)

    Xiao-Nan Sun; Qi Wang; Ben-Xing Gu; Yan-Hong Zhu; Jian-Bin Hu; Guo-Zhi Shi; Shu Zheng

    2011-01-01

    AIM: To assess the efficacy and toxicity of conformal radiotherapy (CRT) and compare with intensity-modulated radiotherapy (IMRT) in the treatment of gallbladder cancer.METHODS: Between November 2003 and January 2010, 20 patients with gallbladder cancer were treated with CRT with or without chemotherapy after surgical resection. Preliminary survival data were collected and examined using both Kaplan-Meier and actuarial analysis. Demographic and treatment parameters were collected. All patients were planned to receive 46-56 Gy in 1.8 or 2.0 Gy per fraction. CRT planning was compared with IMRT.RESULTS: The most common reported acute toxicities requiring medication (Radiation Therapy Oncology Group, Radiation Therapy Oncology Group Grade2) were nausea (10/20 patients) and diarrhea (3/20).There were no treatment-related deaths. Compared with CRT planning, IMRT significantly reduced the volume of right kidney receiving > 20 Gy and the volume of liver receiving > 30 Gy. IMRT has a negligible impact on the volume of left kidney receiving > 20 Gy. The 95% of prescribed dose for a planning tumor volume using either 3D CRT or IMRT planning were 84.0% ±6.7%, 82.9% ± 6.1%, respectively (P > 0.05).CONCLUSION: IMRT achieves similar excellent target coverage as compared with CRT planning, while reducingthe mean liver dose and volume above threshold dose. IMRT offers better sparing of the right kidney compared with CRT planning, with a significantly lower mean dose and volume above threshold dose.

  12. Pleural Intensity-Modulated Radiotherapy for Malignant Pleural Mesothelioma

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    Rosenzweig, Kenneth E., E-mail: ken.rosenzweig@mountsinai.org [Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY (United States); Zauderer, Marjorie G. [Department of Medicine, Thoracic Oncology Service, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Laser, Benjamin [Department of Radiation Oncology, Henry Ford Hospital, Detroit, MI (United States); Krug, Lee M. [Department of Medicine, Thoracic Oncology Service, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Yorke, Ellen [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Sima, Camelia S. [Department of Epidemiology/Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Rimner, Andreas [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Flores, Raja [Department of Surgery, Mount Sinai Medical Center, New York, NY (United States); Rusch, Valerie [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2012-07-15

    Purpose: In patients with malignant pleural mesothelioma who are unable to undergo pneumonectomy, it is difficult to deliver tumoricidal radiation doses to the pleura without significant toxicity. We have implemented a technique of using intensity-modulated radiotherapy (IMRT) to treat these patients, and we report the feasibility and toxicity of this approach. Methods and Materials: Between 2005 and 2010, 36 patients with malignant pleural mesothelioma and two intact lungs (i.e., no previous pneumonectomy) were treated with pleural IMRT to the hemithorax (median dose, 46.8 Gy; range, 41.4-50.4) at Memorial Sloan-Kettering Cancer Center. Results: Of the 36 patients, 56% had right-sided tumors. The histologic type was epithelial in 78%, sarcomatoid in 6%, and mixed in 17%, and 6% had Stage I, 28% had Stage II, 33% had Stage III, and 33% had Stage IV. Thirty-two patients (89%) received induction chemotherapy (mostly cisplatin and pemetrexed); 56% underwent pleurectomy/decortication before IMRT and 44% did not undergo resection. Of the 36 patients evaluable for acute toxicity, 7 (20%) had Grade 3 or worse pneumonitis (including 1 death) and 2 had Grade 3 fatigue. In 30 patients assessable for late toxicity, 5 had continuing Grade 3 pneumonitis. For patients treated with surgery, the 1- and 2-year survival rate was 75% and 53%, and the median survival was 26 months. For patients who did not undergo surgical resection, the 1- and 2-year survival rate was 69% and 28%, and the median survival was 17 months. Conclusions: Treating the intact lung with pleural IMRT in patients with malignant pleural mesothelioma is a safe and feasible treatment option with an acceptable rate of pneumonitis. Additionally, the survival rates were encouraging in our retrospective series, particularly for the patients who underwent pleurectomy/decortication. We have initiated a Phase II trial of induction chemotherapy with pemetrexed and cisplatin with or without pleurectomy

  13. Optimizing Planning and Delivery of High-Precision Robotic Radiotherapy and Intensity-Modulated Proton Therapy

    NARCIS (Netherlands)

    S. van de Water (Steven)

    2015-01-01

    markdownabstract__Abstract__ High-precision robotic radiotherapy and intensity-modulated proton therapy (IMPT) are two relatively new radiotherapy techniques that particularly aim at a highly localized delivery of a curative dose to the tumor, while achieving excellent sparing of the surrounding

  14. Limited benefit of inversely optimised intensity modulation in breast conserving radiotherapy with simultaneously integrated boost

    NARCIS (Netherlands)

    van der Laan, Hans Paul; Dolsma, Willemtje; Schilstra, C; Korevaar, Erik W; de Bock, Geertruida H; Maduro, John H; Langendijk, Johannes A

    2010-01-01

    BACKGROUND AND PURPOSE: To examine whether in breast-conserving radiotherapy (RT) with simultaneously integrated boost (SIB), application of inversely planned intensity-modulated radiotherapy (IMRT-SIB) instead of three-dimensional RT (3D-CRT-SIB) has benefits that justify the additional costs, and

  15. Optimizing Planning and Delivery of High-Precision Robotic Radiotherapy and Intensity-Modulated Proton Therapy

    NARCIS (Netherlands)

    S. van de Water (Steven)

    2015-01-01

    markdownabstract__Abstract__ High-precision robotic radiotherapy and intensity-modulated proton therapy (IMPT) are two relatively new radiotherapy techniques that particularly aim at a highly localized delivery of a curative dose to the tumor, while achieving excellent sparing of the surrounding he

  16. Implementation of intensity modulation with dynamic multileaf collimation

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    Wong, J.W.; Yu, C.; Jaffray, D. [William Beaumont Hospital, Royal Oak, MI (United States)

    1995-12-01

    The computer-controlled multileaf collimator (MLC) marks one of the most important advances in radiation therapy. The device efficiently replaces manual blocking to shape fields and can be used to modulate beam intensity. The results of a research programme at William Beaumont Hospital, aimed at bringing dynamic intensity modulation into clinical use, are discussed.

  17. Image guided position verification for intensity modulated radiotherapy of prostate cancer

    NARCIS (Netherlands)

    Nederveen, A.J.

    2002-01-01

    The aim of this thesis is to provide a practical framework for dose escalation in the prostate using intensity modulated radiotherapy (IMRT) and to find out if marker based on-line position verification is clinically feasible and effective. We present a class solution for dose escalation in the pros

  18. Single arc volumetric-modulated arc therapy is sufficient for nasopharyngeal carcinoma: a dosimetric comparison with dual arc VMAT and dynamic MLC and step-and-shoot intensity-modulated radiotherapy

    Science.gov (United States)

    2013-01-01

    Background The performance of single arc VMAT (VMAT1) for nasopharyngeal carcinoma (NPC) on the Axesse linac has not been well described in previous studies. The purpose of this study is to assess the feasibility of VMAT1 for NPC by comparing the dosimetry, delivery efficiency, and accuracy with dual arc VMAT (VMAT2), dynamic MLC intensity-modulated radiotherapy (dIMRT), and step-and-shoot intensity-modulated radiotherapy (ssIMRT). Methods Twenty consecutive patients with non-metastatic NPC were selected to be planned with VMAT1, VMAT2, dIMRT and ssIMRT using Monaco 3.2 TPS on the Axesse™ linear accelerator. Three planning target volumes (PTVs), contoured as high risk, moderate risk and low risk regions, were set to receive median absorbed-dose (D50%) of 72.6 Gy, 63.6 Gy and 54 Gy, respectively. The Homogeneity Index (HI), Conformity Index (CI), Dose Volume Histograms (DVHs), delivery efficiency and accuracy were all evaluated. Results Mean HI of PTV72.6 is better with VMAT1(0.07) and VMAT2(0.07) than dIMRT(0.09) and ssIMRT(0.09). Mean HI of PTV63.6 is better with VMAT1(0.21) and VMAT2(0.21) than dIMRT and ssIMRT. Mean CI of PTV72.6 is also better with VMAT1(0.57) and VMAT2(0.57) than dIMRT(0.49) and ssIMRT(0.5). Mean CI of PTV63.6 is better with VMAT1(0.76) and VMAT2(0.76) than dIMRT(0.73) and ssIMRT(0.73). VMAT had significantly improved homogeneity and conformity compared with IMRT. There was no significant difference between VMAT1 and VMAT2 in PTV coverage. Dose to normal tissues was acceptable for all four plan groups. VMAT1 and VMAT2 showed no significant difference in normal tissue sparring, whereas the mean dose of the parotid gland of dIMRT was significantly reduced compared to VMAT1 and VMAT2. The mean delivery time for VMAT1, VMAT2, dIMRT and ssIMRT was 2.7 min, 3.9 min, 5.7 min and 14.1 min, respectively. VMAT1 reduced the average delivery time by 29.8%, 51.1% and 80.8% compared with VMAT2, dIMRT and ssIMRT, respectively. VMAT and IMRT could all be

  19. Clinical results of a pilot study on stereovision-guided stereotactic radiotherapy and intensity modulated radiotherapy.

    Science.gov (United States)

    Li, Shidong; Kleinberg, Lawrence R; Rigamonti, Daniele; Wharam, Moody D; Rashid, Abdul; Jackson, Juan; Djajaputra, David; He, Shenjen; Creasey, Tunisia; DeWeese, Theodore L

    2010-12-01

    Real-time stereovision-guidance has been introduced for efficient and convenient fractionated stereotactic radiotherapy (FSR) and image-guided intensity-modulated radiation therapy (IMRT). This first pilot study is to clinically evaluate its accuracy and precision as well as impact on treatment doses. Sixty-one FSR patients wearing stereotactic masks (SMs) and nine IMRT patients wearing flexible masks (FMs), were accrued. Daily target reposition was initially based-on biplane-radiographs and then adjusted in six degrees of freedom under real-time stereovision guidance. Mean and standard deviation of the head displacements measured the accuracy and precision. Head positions during beam-on times were measured with real-time stereovisions and used for determination of delivered doses. Accuracy ± ± precision in direction with the largest errors shows improvement from 0.4 ± 2.3 mm to 0.0 ± 1.0 mm in the inferior-to-superior direction for patients wearing SM or from 0.8 ± 4.3 mm to 0.4 ± 1.7 mm in the posterior-to-anterior direction for patients wearing FM. The image-guidance increases target volume coverage by >30% for small lesions. Over half of head position errors could be removed from the stereovision-guidance. Importantly, the technique allows us to check head position during beam-on time and makes it possible for having frameless head refixation without tight masks.

  20. A Comparison of Helical Intensity-Modulated Radiotherapy, Intensity-Modulated Radiotherapy, and 3D-Conformal Radiation Therapy for Pancreatic Cancer

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    Poppe, Matthew M.; Narra, Venkat; Yue, Ning J.; Zhou Jinghao; Nelson, Carl [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States); Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States); Jabbour, Salma K., E-mail: jabbousk@umdnj.edu [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States); Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States)

    2011-01-01

    We assessed dosimetric differences in pancreatic cancer radiotherapy via helical intensity-modulated radiotherapy (HIMRT), linac-based IMRT, and 3D-conformal radiation therapy (3D-CRT) with regard to successful plan acceptance and dose to critical organs. Dosimetric analysis was performed in 16 pancreatic cases that were planned to 54 Gy; both post-pancreaticoduodenectomy (n = 8) and unresected (n = 8) cases were compared. Without volume modification, plans met constraints 75% of the time with HIMRT and IMRT and 13% with 3D-CRT. There was no statistically significantly improvement with HIMRT over conventional IMRT in reducing liver V35, stomach V45, or bowel V45. HIMRT offers improved planning target volume (PTV) dose homogeneity compared with IMRT, averaging a lower maximum dose and higher volume receiving the prescription dose (D100). HIMRT showed an increased mean dose over IMRT to bowel and liver. Both HIMRT and IMRT offer a statistically significant improvement over 3D-CRT in lowering dose to liver, stomach, and bowel. The results were similar for both unresected and resected patients. In pancreatic cancer, HIMRT offers improved dose homogeneity over conventional IMRT and several significant benefits to 3D-CRT. Factors to consider before incorporating IMRT into pancreatic cancer therapy are respiratory motion, dose inhomogeneity, and mean dose.

  1. Dosimetric Comparison of Three-Dimensional Conformal Proton Radiotherapy, Intensity-Modulated Proton Therapy, and Intensity-Modulated Radiotherapy for Treatment of Pediatric Craniopharyngiomas

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    Boehling, Nicholas S. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Grosshans, David R., E-mail: dgrossha@mdanderson.org [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Bluett, Jaques B. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Palmer, Matthew T. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Song, Xiaofei; Amos, Richard A.; Sahoo, Narayan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Meyer, Jeffrey J.; Mahajan, Anita; Woo, Shiao Y. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

    2012-02-01

    Purpose: Cranial irradiation in pediatric patients is associated with serious long-term adverse effects. We sought to determine whether both three-dimensional conformal proton radiotherapy (3D-PRT) and intensity-modulated proton therapy (IMPT) compared with intensity-modulated radiotherapy (IMRT) decrease integral dose to brain areas known to harbor neuronal stem cells, major blood vessels, and other normal brain structures for pediatric patients with craniopharyngiomas. Methods and Materials: IMRT, forward planned, passive scattering proton, and IMPT plans were generated and optimized for 10 pediatric patients. The dose was 50.4 Gy (or cobalt Gy equivalent) delivered in 28 fractions with the requirement for planning target volume (PTV) coverage of 95% or better. Integral dose data were calculated from differential dose-volume histograms. Results: The PTV target coverage was adequate for all modalities. IMRT and IMPT yielded the most conformal plans in comparison to 3D-PRT. Compared with IMRT, 3D-PRT and IMPT plans had a relative reduction of integral dose to the hippocampus (3D-PRT, 20.4; IMPT, 51.3%{sup Asterisk-Operator }), dentate gyrus (27.3, 75.0%{sup Asterisk-Operator }), and subventricular zone (4.5, 57.8%{sup Asterisk-Operator }). Vascular organs at risk also had reduced integral dose with the use of proton therapy (anterior cerebral arteries, 33.3{sup Asterisk-Operator }, 100.0%{sup Asterisk-Operator }; middle cerebral arteries, 25.9%{sup Asterisk-Operator }, 100%{sup Asterisk-Operator }; anterior communicating arteries, 30.8{sup Asterisk-Operator }, 41.7%{sup Asterisk-Operator }; and carotid arteries, 51.5{sup Asterisk-Operator }, 77.6{sup Asterisk-Operator }). Relative reduction of integral dose to the infratentorial brain (190.7{sup Asterisk-Operator }, 109.7%{sup Asterisk-Operator }), supratentorial brain without PTV (9.6, 26.8%{sup Asterisk-Operator }), brainstem (45.6, 22.4%{sup Asterisk-Operator }), and whole brain without PTV (19.4{sup Asterisk

  2. Estimating the costs of intensity-modulated and 3-dimensional conformal radiotherapy in Ontario.

    Science.gov (United States)

    Yong, J H E; McGowan, T; Redmond-Misner, R; Beca, J; Warde, P; Gutierrez, E; Hoch, J S

    2016-06-01

    Radiotherapy is a common treatment for many cancers, but up-to-date estimates of the costs of radiotherapy are lacking. In the present study, we estimated the unit costs of intensity-modulated radiotherapy (imrt) and 3-dimensional conformal radiotherapy (3D-crt) in Ontario. An activity-based costing model was developed to estimate the costs of imrt and 3D-crt in prostate cancer. It included the costs of equipment, staff, and supporting infrastructure. The framework was subsequently adapted to estimate the costs of radiotherapy in breast cancer and head-and-neck cancer. We also tested various scenarios by varying the program maturity and the use of volumetric modulated arc therapy (vmat) alongside imrt. From the perspective of the health care system, treating prostate cancer with imrt and 3D-crt respectively cost $12,834 and $12,453 per patient. The cost of radiotherapy ranged from $5,270 to $14,155 and was sensitive to analytic perspective, radiation technique, and disease site. Cases of head-and-neck cancer were the most costly, being driven by treatment complexity and fractions per treatment. Although imrt was more costly than 3D-crt, its cost will likely decline over time as programs mature and vmat is incorporated. Our costing model can be modified to estimate the costs of 3D-crt and imrt for various disease sites and settings. The results demonstrate the important role of capital costs in studies of radiotherapy cost from a health system perspective, which our model can accommodate. In addition, our study established the need for future analyses of imrt cost to consider how vmat affects time consumption.

  3. Estimating the costs of intensity-modulated and 3-dimensional conformal radiotherapy in Ontario

    Science.gov (United States)

    Yong, J.H.E.; McGowan, T.; Redmond-Misner, R.; Beca, J.; Warde, P.; Gutierrez, E.; Hoch, J.S.

    2016-01-01

    Background Radiotherapy is a common treatment for many cancers, but up-to-date estimates of the costs of radiotherapy are lacking. In the present study, we estimated the unit costs of intensity-modulated radiotherapy (imrt) and 3-dimensional conformal radiotherapy (3D-crt) in Ontario. Methods An activity-based costing model was developed to estimate the costs of imrt and 3D-crt in prostate cancer. It included the costs of equipment, staff, and supporting infrastructure. The framework was subsequently adapted to estimate the costs of radiotherapy in breast cancer and head-and-neck cancer. We also tested various scenarios by varying the program maturity and the use of volumetric modulated arc therapy (vmat) alongside imrt. Results From the perspective of the health care system, treating prostate cancer with imrt and 3D-crt respectively cost $12,834 and $12,453 per patient. The cost of radiotherapy ranged from $5,270 to $14,155 and was sensitive to analytic perspective, radiation technique, and disease site. Cases of head-and-neck cancer were the most costly, being driven by treatment complexity and fractions per treatment. Although imrt was more costly than 3D-crt, its cost will likely decline over time as programs mature and vmat is incorporated. Conclusions Our costing model can be modified to estimate the costs of 3D-crt and imrt for various disease sites and settings. The results demonstrate the important role of capital costs in studies of radiotherapy cost from a health system perspective, which our model can accommodate. In addition, our study established the need for future analyses of imrt cost to consider how vmat affects time consumption. PMID:27330359

  4. Rationale and development of image-guided intensity-modulated radiotherapy post-prostatectomy: the present standard of care?

    Directory of Open Access Journals (Sweden)

    Murray JR

    2015-11-01

    Full Text Available Julia R Murray,1,2 Helen A McNair,2 David P Dearnaley1,2 1Academic Urology Unit, Institute of Cancer Research, London, 2Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, Sutton, UK Abstract: The indications for post-prostatectomy radiotherapy have evolved over the last decade, although the optimal timing, dose, and target volume remain to be well defined. The target volume is susceptible to anatomical variations with its borders interfacing with the rectum and bladder. Image-guided intensity-modulated radiotherapy has become the gold standard for radical prostate radiotherapy. Here we review the current evidence for image-guided techniques with intensity-modulated radiotherapy to the prostate bed and describe current strategies to reduce or account for interfraction and intrafraction motion. Keywords: radiotherapy, prostate cancer, post-prostatectomy, image-guided radiation therapy

  5. The Dosimetric Consequences of Intensity Modulated Radiotherapy for Cervix Cancer: The Impact of Organ Motion, Deformation and Tumour Regression

    Science.gov (United States)

    Lim, Karen Siah Huey

    Hypothesis: In intensity modulated radiotherapy (IMRT) for cervix cancer, the dose received by the tumour target and surrounding normal tissues is significantly different to that indicated by a single static plan. Rationale: The optimal use of IMRT in cervix cancer requires a greater attention to clinical target volume (CTV) definition and tumour & normal organ motion to assure maximum tumour control with the fewest side effects. Research Aims: 1) Generate consensus CTV contouring guidelines for cervix cancer; 2) Evaluate intra-pelvic tumour and organ dynamics during radiotherapy; 3) Analyze the dose consequences of intra-pelvic organ dynamics on different radiotherapy strategies. Results: Consensus CTV definitions were generated using experts-in-the-field. Substantial changes in tumour volume and organ motion, resulted in significant reductions in accumulated dose to tumour targets and variability in accumulated dose to surrounding normal tissues. Significance: Formalized CTV definitions for cervix cancer is important in ensuring consistent standards of practice. Complex and unpredictable tumour and organ dynamics mandates daily soft-tissue image guidance if IMRT is used. To maximize the benefits of IMRT for cervix cancer, a strategy of adaptation is necessary.

  6. Dosimetric comparison between jaw tracking and static jaw techniques in intensity-modulated radiotherapy.

    Science.gov (United States)

    Feng, Zhongsu; Wu, Hao; Zhang, Yibao; Zhang, Yunjun; Cheng, Jinsheng; Su, Xu

    2015-01-27

    To compare the dosimetric differences between jaw tracking technique (JTT) and static jaw technique (SJT) in dynamic intensity-modulated radiotherapy (d-IMRT) and assess the potential advantages of jaw tracking technique. Two techniques, jaw tracking and static jaw, were used respectively to develop the d-IMRT plans for 28 cancer patients with various lesion sites: head and neck, lungs, esophageal, abdominal, prostate, rectal and cervical. The dose volume histograms (DVH) and selected dosimetric indexes for the whole body and for organs at risk (OARs) were compared. A two dimensional ionization chamber Array Seven29 (PTW, Freiburg, Germany) and OCTAVIUS Octagonal phantom (PTW, Freiburg, Germany) were used to verify all the plans. For all patients, the treatment plans using both techniques met the clinical requirements. The V5, V10, V20, V30, V40 (volumes receiving 5, 10, 20, 30 and 40 Gy at least, respectively), mean dose (Dmean) for the whole body and V5, V10, V20, Dmean for lungs in the JTT d-IMRT plans were significantly less than the corresponding values of the SJT d-IMRT plans (p < 0.001). The JTT d-IMRT plans deposited lower maximum dose (Dmax) to the lens, eyes, brainstem, spinal cord, and right optic nerve, the doses reductions for these OARs ranged from 2.2% to 28.6%. The JTT d-IMRT plans deposited significantly lower Dmean to various OARs (all p values < 0.05), the mean doses reductions for these OARs ranged from 1.1% to 31.0%, and the value reductions depend on the volume and the location of the OARs. The γ evaluation method showed an excellent agreement between calculation and measurement for all techniques with criteria of 3%/3 mm. Both jaw tracking and static jaw d-IMRT plans can achieve comparable target dose coverage. JTT displays superior OARs sparing than SJT plans. These results are of clinical importance, especially for the patients with large and complex targets but close to some highly radio-sensitive organs to spare, and for patients

  7. Risk of second malignant neoplasm following proton versus intensity-modulated photon radiotherapies for hepatocellular carcinoma

    Science.gov (United States)

    Taddei, Phillip J.; Howell, Rebecca M.; Krishnan, Sunil; Scarboro, Sarah B.; Mirkovic, Dragan; Newhauser, Wayne D.

    2010-12-01

    Hepatocellular carcinoma (HCC), the sixth most common cancer in the world, is a global health concern. Radiotherapy for HCC is uncommon, largely because of the likelihood of radiation-induced liver disease, an acute side effect that is often fatal. Proton beam therapy (PBT) and intensity-modulated radiation therapy (IMRT) may offer HCC patients a better option for treating the diseased liver tissue while largely sparing the surrounding tissues, especially the non-tumor liver. However, even advanced radiotherapies carry a risk of late effects, including second malignant neoplasms (SMNs). It is unclear whether PBT or IMRT confers less risk of an SMN than the other. The purpose of this study was to compare the predicted risk of developing an SMN for a patient with HCC between PBT and IMRT. For both treatments, radiation doses in organs and tissues from primary radiation were determined using a treatment planning system; doses in organs and tissues from stray radiation from PBT were determined using Monte Carlo simulations and from IMRT using thermo-luminescent dosimeter measurements. Risk models of SMN incidence were taken from the literature. The predicted absolute lifetime attributable risks of SMN incidence were 11.4% after PBT and 19.2% after IMRT. The results of this study suggest that using proton beams instead of photon beams for radiotherapy may reduce the risk of SMN incidence for some HCC patients.

  8. Risk of second malignant neoplasm following proton versus intensity-modulated photon radiotherapies for hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Taddei, Phillip J; Howell, Rebecca M; Krishnan, Sunil; Scarboro, Sarah B; Mirkovic, Dragan; Newhauser, Wayne D, E-mail: ptaddei@mdanderson.or [Division of Radiation Oncology, Unit 1202, University of Texas M D Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030 (United States)

    2010-12-07

    Hepatocellular carcinoma (HCC), the sixth most common cancer in the world, is a global health concern. Radiotherapy for HCC is uncommon, largely because of the likelihood of radiation-induced liver disease, an acute side effect that is often fatal. Proton beam therapy (PBT) and intensity-modulated radiation therapy (IMRT) may offer HCC patients a better option for treating the diseased liver tissue while largely sparing the surrounding tissues, especially the non-tumor liver. However, even advanced radiotherapies carry a risk of late effects, including second malignant neoplasms (SMNs). It is unclear whether PBT or IMRT confers less risk of an SMN than the other. The purpose of this study was to compare the predicted risk of developing an SMN for a patient with HCC between PBT and IMRT. For both treatments, radiation doses in organs and tissues from primary radiation were determined using a treatment planning system; doses in organs and tissues from stray radiation from PBT were determined using Monte Carlo simulations and from IMRT using thermo-luminescent dosimeter measurements. Risk models of SMN incidence were taken from the literature. The predicted absolute lifetime attributable risks of SMN incidence were 11.4% after PBT and 19.2% after IMRT. The results of this study suggest that using proton beams instead of photon beams for radiotherapy may reduce the risk of SMN incidence for some HCC patients.

  9. Intensity modulated radiotherapy for sinonasal malignancies with a focus on optic pathway preservation

    Directory of Open Access Journals (Sweden)

    Chi Alexander

    2013-01-01

    Full Text Available Abstract Purpose To assess if intensity-modulated radiotherapy (IMRT can possibly lead to improved local control and lower incidence of vision impairment/blindness in comparison to non-IMRT techniques when treating sinonasal malignancies; what is the most optimal dose constraints for the optic pathway; and the impact of different IMRT strategies on optic pathway sparing in this setting. Methods and materials A literature search in the PubMed databases was conducted in July, 2012. Results Clinical studies on IMRT and 2D/3D (2 dimensional/3 dimensional RT for sinonasal malignancies suggest improved local control and lower incidence of severe vision impairment with IMRT in comparison to non-IMRT techniques. As observed in the non-IMRT studies, blindness due to disease progression may occur despite a lack of severe toxicity possibly due to the difficulty of controlling locally very advanced disease with a dose ≤ 70 Gy. Concurrent chemotherapy’s influence on the the risk of severe optic toxicity after radiotherapy is unclear. A maximum dose of ≤ 54 Gy with conventional fractionation to the optic pathway may decrease the risk of blindness. Increased magnitude of intensity modulation through increasing the number of segments, beams, and using a combination of coplanar and non-coplanar arrangements may help increase dose conformality and optic pathway sparing when IMRT is used. Conclusion IMRT optimized with appropriate strategies may be the treatment of choice for the most optimal local control and optic pathway sparing when treating sinonasal malignancy.

  10. Hypofractionated intensity-modulated radiotherapy in patients with localized prostate cancer: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hye Jin; Kay, Chul Seung; Son, Seok Hyun; Kim, Myung Soo; Jo, In Young; Lee, So Jung; Lee, Dong Hwan; Suh, Hong Jin; Choi, Yong Sun [Incheon St. Mary' s Hospital, The Catholic University of Korea College of Medicine, Incheon (Korea, Republic of)

    2016-03-15

    The aim of this work was to assess the efficacy and tolerability of hypofractionated intensity-modulated radiotherapy (IMRT) in patients with localized prostate cancer. Thirty-nine patients who received radical hypofractionated IMRT were retrospectively reviewed. Based on a pelvic lymph node involvement risk of 15% as the cutoff value, we decided whether to deliver treatment prostate and seminal vesicle only radiotherapy (PORT) or whole pelvis radiotherapy (WPRT). Sixteen patients (41%) received PORT with prostate receiving 45 Gy in 4.5 Gy per fraction in 2 weeks and the other 23 patients (59%) received WPRT with the prostate receiving 72 Gy in 2.4 Gy per fraction in 6 weeks. The median equivalent dose in 2 Gy fractions to the prostate was 79.9 Gy based on the assumption that the α/β ratio is 1.5 Gy. The median follow-up time was 38 months (range, 4 to 101 months). The 3-year biochemical failure-free survival rate was 88.2%. The 3-year clinical failure-free and overall survival rates were 94.5% and 96.3%, respectively. The rates of grade 2 acute genitourinary (GU) and gastrointestinal (GI) toxicities were 20.5% and 12.8%, respectively. None of the patients experienced grade ≥3 acute GU and GI toxicities. The grade 2-3 late GU and GI toxicities were found in 8.1% and 5.4% of patients, respectively. No fatal late toxicity was observed. Favorable biochemical control with low rates of toxicity was observed after hypofractionated IMRT, suggesting that our radiotherapy schedule can be an effective treatment option in the treatment of localized prostate cancer.

  11. The Cambridge Breast Intensity-modulated Radiotherapy Trial: Comparison of Clinician- versus Patient-reported Outcomes.

    Science.gov (United States)

    Mukesh, M B; Qian, W; Wah Hak, C C; Wilkinson, J S; Barnett, G C; Moody, A M; Wilson, C; Coles, C E

    2016-06-01

    Breast radiotherapy-associated toxicity is often reported using clinical and photographic assessments. The addition of patient-reported outcome measures (PROMs) is becoming more common. This study investigated the concordance between clinician- and patient-reported outcomes. The Cambridge Breast Intensity-modulated Radiotherapy (IMRT) trial prospectively collected data on clinician assessment and PROMs at 2 and 5 years after breast radiotherapy. Clinician assessment included physical examination and photographic assessment. PROMs included European Organization for Research and Treatment of Cancer (EORTC) BR23 questionnaire and four breast radiotherapy-specific questions. The correlation between patient and clinician scores were analysed on an independent patient basis using percentage agreement, Cohen's kappa coefficient (k) and Bowker's test of symmetry. The analysis was repeated after stratifying patients based on age, baseline Hospital Anxiety and Depression Score (HADS) and baseline body image score. At 2 and 5 years, a weak level of concordance was seen between the clinician-based assessment and PROMS for all the five toxicity end points (k = 0.05-0.21), with individual patient-based agreement of 32.9-78.3% and a highly discordant Bowker's test of symmetry (P < 0.001). The most frequently reported moderate-severe toxicity by patients was change in breast appearance (14% at both 2 and 5 years), whereas it was breast induration (36% and 25% at 2 and 5 years, respectively) by the clinicians. The lack of concordance was not affected by patient's age, baseline HADS and baseline body image score. This study found that moderate-severe toxicity reported by patients is low and the overall concordance between clinicians and patients is low. This could be due to methodological limitations or alternatively reflects the subjective nature of PROMs. Incorporation of a patient's perception on treatment-related toxicity will have important implications for treatment

  12. Implementation of intensity modulated radiotherapy for prostate cancer in a private radiotherapy service in Mexico

    Science.gov (United States)

    Poitevin-Chacón, María Adela; Reséndiz González, Gabriel; Alvarado Zermeño, Adriana; Flores Castro, Jesús Manuel; Flores Balcázar, Christian Haydée; Rosales Pérez, Samuel; Pérez Pastenes, Miguel Angel; Rodríguez Laguna, Alejandro; Vázquez Fernández, Patricio; Calvo Fernández, Alejandro; Bastida Ventura, Jorge

    2014-01-01

    Intensity modulated radiation therapy (IMRT) allows physicians to deliver higher conformal doses to the tumour, while avoiding adjacent structures. As a result the probability of tumour control is higher and toxicity may be reduced. However, implementation of IMRT is highly complex and requires a rigorous quality assurance (QA) program both before and during treatment. The present article describes the process of implementing IMRT for localized prostate cancer in a radiation therapy department. In our experience, IMRT implementation requires careful planning due to the need to simultaneously implement specialized software, multifaceted QA programs, and training of the multidisciplinary team. Establishing standardized protocols and ensuring close collaboration between a multidisciplinary team is challenging but essential. PMID:25535587

  13. Retrospective Estimation of the Quality of Intensity-Modulated Radiotherapy Plans for Lung Cancer

    CERN Document Server

    Koo, Jihye; Chung, Weon Kuu; Kim, Dong Wook

    2015-01-01

    This study estimated the planning quality of intensity-modulated radiotherapy in 42 lung cancer cases to provide preliminary data for the development of a planning quality assurance algorithm. Organs in or near the thoracic cavity (ipsilateral lung, contralateral lung, heart, liver, esophagus, spinal cord, and bronchus) were selected as organs at risk (OARs). Radiotherapy plans were compared using the conformity index (CI), coverage index (CVI), and homogeneity index (HI) of the planning target volume (PTV), OAR-PTV distance and OAR-PTV overlap volume, and the V10Gy, V20Gy, and equivalent uniform dose (EUD) of the OARs. The CI, CVI, and HI of the PTV were 0.54 - 0.89 , 0.90 - 1.00 , and 0.11 - 0.41, respectively. The mean EUDs (V10Gy, V20Gy) of the ipsilateral lung, contralateral lung, esophagus, cord, liver, heart, and bronchus were 8.07 Gy (28.06, 13.17), 2.59 Gy (6.53, 1.18), 7.02 Gy (26.17, 12.32), 3.56 Gy (13.56, 4.48), 0.72 Gy (2.15, 0.91), 5.14 Gy (19.68, 8.62), and 10.56 Gy (36.08, 19.79), respectivel...

  14. Long-term decision regret after post-prostatectomy image-guided intensity-modulated radiotherapy.

    Science.gov (United States)

    Shakespeare, Thomas P; Chin, Stephen; Manuel, Lucy; Wen, Shelly; Hoffman, Matthew; Wilcox, Shea W; Aherne, Noel J

    2017-02-01

    Decision regret (DR) may occur when a patient believes their outcome would have been better if they had decided differently about their management. Although some studies investigate DR after treatment for localised prostate cancer, none report DR in patients undergoing surgery and post-prostatectomy radiotherapy. We evaluated DR in this group of patients overall, and for specific components of therapy. We surveyed 83 patients, with minimum 5 years follow-up, treated with radical prostatectomy (RP) and post-prostatectomy image-guided intensity-modulated radiotherapy (IG-IMRT) to 64-66 Gy following www.EviQ.org.au protocols. A validated questionnaire identified DR if men either indicated that they would have been better off had they chosen another treatment, or they wished they could change their mind about treatment. There was an 85.5% response rate, with median follow-up post-IMRT 78 months. Adjuvant IG-IMRT was used in 28% of patients, salvage in 72% and ADT in 48%. A total of 70% of patients remained disease-free. Overall, 16.9% of patients expressed DR for treatment, with fourfold more regret for the RP component of treatment compared to radiotherapy (16.9% vs 4.2%, P = 0.01). DR for androgen deprivation was 14.3%. Patients were regretful of surgery due to toxicity, not being adequately informed about radiotherapy as an alternative, positive margins and surgery costs (83%, 33%, 25% and 8% of regretful patients respectively). Toxicity caused DR in the three radiotherapy-regretful and four ADT-regretful patients. Patients were twice as regretful overall, and of surgery, for salvage vs adjuvant approaches (both 19.6% vs 10.0%). Decision regret after RP and post-prostatectomy IG-IMRT is uncommon, although patients regret RP more than post-operative IG-IMRT. This should reassure urologists referring patients for post-prostatectomy IG-IMRT, particularly in the immediate adjuvant setting. Other implications include appropriate patient selection for RP (and

  15. RISK FACTORS FOR HEARING LOSS IN PATIENTS TREATED WITH INTENSITY-MODULATED RADIOTHERAPY FOR HEAD-AND-NECK TUMORS

    NARCIS (Netherlands)

    C.L. Zuur; Y.J. Simis; E.A. Lamers; A.A. Hart; W.A. Dreschler; A.J. Balm; C.R. Rasch

    2009-01-01

    Purpose: Radiotherapy (RT) is a common treatment of head-and-neck carcinoma. The objective of this study was to perform a prospective multivariate assessment of the dose-effect relationship between intensity-modulated RT and hearing loss. Methods and Materials: Pure tone audiometry at 0.250-16 kHz w

  16. The potential benefit of swallowing sparing intensity modulated radiotherapy to reduce swallowing dysfunction : An in silico planning comparative study

    NARCIS (Netherlands)

    van der Laan, Hans Paul; Christianen, Miranda E M C; Bijl, Hendrik P; Schilstra, C; Langendijk, Johannes A

    2012-01-01

    PURPOSE: To apply recently developed predictive models for swallowing dysfunction to compare the predicted probabilities of swallowing dysfunction for standard intensity modulated radiotherapy (ST-IMRT) and swallowing sparing IMRT (SW-IMRT). MATERIALS AND METHODS: Thirty head and neck cancer patient

  17. Reduced Acute Bowel Toxicity in Patients Treated With Intensity-Modulated Radiotherapy for Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Samuelian, Jason M. [Department of Radiation Oncology, Mayo Clinic, Scottsdale, AZ (United States); Callister, Matthew D., E-mail: Callister.matthew@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Scottsdale, AZ (United States); Ashman, Jonathan B. [Department of Radiation Oncology, Mayo Clinic, Scottsdale, AZ (United States); Young-Fadok, Tonia M. [Division of Colorectal Surgery, Mayo Clinic, Scottsdale, AZ (United States); Borad, Mitesh J. [Division of Hematology-Oncology, Mayo Clinic, Scottsdale, AZ (United States); Gunderson, Leonard L. [Department of Radiation Oncology, Mayo Clinic, Scottsdale, AZ (United States)

    2012-04-01

    Purpose: We have previously shown that intensity-modulated radiotherapy (IMRT) can reduce dose to small bowel, bladder, and bone marrow compared with three-field conventional radiotherapy (CRT) technique in the treatment of rectal cancer. The purpose of this study was to review our experience using IMRT to treat rectal cancer and report patient clinical outcomes. Methods and Materials: A retrospective review was conducted of patients with rectal cancer who were treated at Mayo Clinic Arizona with pelvic radiotherapy (RT). Data regarding patient and tumor characteristics, treatment, acute toxicity according to the Common Terminology Criteria for Adverse Events v 3.0, tumor response, and perioperative morbidity were collected. Results: From 2004 to August 2009, 92 consecutive patients were treated. Sixty-one (66%) patients were treated with CRT, and 31 (34%) patients were treated with IMRT. All but 2 patients received concurrent chemotherapy. There was no significant difference in median dose (50.4 Gy, CRT; 50 Gy, IMRT), preoperative vs. postoperative treatment, type of concurrent chemotherapy, or history of previous pelvic RT between the CRT and IMRT patient groups. Patients who received IMRT had significantly less gastrointestinal (GI) toxicity. Sixty-two percent of patients undergoing CRT experienced {>=}Grade 2 acute GI side effects, compared with 32% among IMRT patients (p = 0.006). The reduction in overall GI toxicity was attributable to fewer symptoms from the lower GI tract. Among CRT patients, {>=}Grade 2 diarrhea and enteritis was experienced among 48% and 30% of patients, respectively, compared with 23% (p = 0.02) and 10% (p = 0.015) among IMRT patients. There was no significant difference in hematologic or genitourinary acute toxicity between groups. In addition, pathologic complete response rates and postoperative morbidity between treatment groups did not differ significantly. Conclusions: In the management of rectal cancer, IMRT is associated with a

  18. Intensity-modulated radiotherapy for cancers in childhood; Radiotherapie conformationnelle par modulation d'intensite des tumeurs pediatriques

    Energy Technology Data Exchange (ETDEWEB)

    Leseur, J.; Le Prise, E. [Centre Eugene-Marquis, Service de Radiotherapie, 35 - Rennes (France); Leseur, J.; Carrie, C.; Beneyton, V. [Centre Leon-Berard, Service de Radiotherapie, 69 - Lyon (France); Bernier, V. [Centre Alexis-Vautrin, Service de Radiotherapie, 54 - Vandoeuvre-les-Nancy (France); Beneyton, V. [Centre Paul-Strauss, Service de Radiotherapie, 67 - Strasbourg (France); Mahee, M.A.; Supiot, S. [Centre Rene-Gauducheau, Service de Radiotherapie, 44 - Nantes - Saint-Herblain (France)

    2009-10-15

    Approximately 40-50% of children with cancer will be irradiated during their treatment. Intensity-modulated radiotherapy (I.M.R.T.) by linear accelerator or helical tomo-therapy improves dose distribution in target volumes and normal tissue sparing. This technology could be particularly useful for pediatric patients to achieve an optimal dose distribution in complex volumes close to critical structures. The use of I.M.R.T. can increase the volume of tissue receiving low-dose radiation, and consequently carcinogenicity in childhood population with a good overall survival and long period of life expectancy. This review will present the current and potential I.M.R.T. indications for cancers in childhood, and discuss the benefits and problems of this technology aiming to define recommendations in the use of I.M.R.T. and specific doses constraints in Pediatrics. (authors)

  19. Pelvic Ewing sarcomas. Three-dimensional conformal vs. intensity-modulated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mounessi, F.S.; Lehrich, P.; Haverkamp, U.; Eich, H.T. [Muenster Univ. (Germany). Dept. of Radiation Oncology; Willich, N. [Muenster Univ. (Germany). Dept. of Radiation Oncology; Universitaetsklinikum Muenster (Germany). RiSK - Registry for the Evaluation of Late Side Effects after Radiotherapy in Childhood and Adolescence; Boelling, T. [Center for Radiation Oncology, Osnabrueck (Germany)

    2013-04-15

    The goal of the present work was to assess the potential advantage of intensity-modulated radiotherapy (IMRT) over three-dimensional conformal radiotherapy (3D-CRT) planning in pelvic Ewing's sarcoma. A total of 8 patients with Ewing sarcoma of the pelvis undergoing radiotherapy were analyzed. Plans for 3D-CRT and IMRT were calculated for each patient. Dose coverage of the planning target volume (PTV), conformity and homogeneity indices, as well as further parameters were evaluated. Results The average dose coverage values for PTV were comparable in 3D-CRT and IMRT plans. Both techniques had a PTV coverage of V{sub 95} > 98 % in all patients. Whereas the IMRT plans achieved a higher conformity index compared to the 3D-CRT plans (conformity index 0.79 {+-} 0.12 vs. 0.54 {+-} 0.19, p = 0.012), the dose distribution across the target volumes was less homogeneous with IMRT planning than with 3D-CRT planning. This difference was statistically significant (homogeneity index 0.11 {+-} 0.03 vs. 0.07 {+-} 0.0, p = 0.035). For the bowel, D{sub mean} and D{sub 1%}, as well as V{sub 2} to V{sub 60} were reduced in IMRT plans. For the bladder and the rectum, there was no significant difference in D{sub mean}. However, the percentages of volumes receiving at least doses of 30, 40, 45, and 50 Gy (V{sub 30} to V{sub 50}) were lower for the rectum in IMRT plans. The volume of normal tissue receiving at least 2 Gy (V{sub 2}) was significantly higher in IMRT plans compared with 3D-CRT, whereas at high dose levels (V{sub 30}) it was significantly lower. Compared to 3D-CRT, IMRT showed significantly better results regarding dose conformity (p = 0.012) and bowel sparing at dose levels above 30 Gy (p = 0.012). Thus, dose escalation in the radiotherapy of pelvic Ewing's sarcoma can be more easily achieved using IMRT. (orig.)

  20. Sparing level Ib lymph nodes by intensity-modulated radiotherapy in the treatment of nasopharyngeal carcinoma.

    Science.gov (United States)

    Chen, Jing; Ou, Dan; He, Xiayun; Hu, Chaosu

    2014-12-01

    We retrospectively investigated the patterns of locoregional relapse and survival of patients to evaluate whether sparing level Ib lymph nodes by intensity-modulated radiotherapy (IMRT) in the treatment of nasopharyngeal carcinoma was feasible. One hundred and twenty nasopharyngeal carcinoma patients received treatment with level Ib lymph nodes spared by IMRT between January 2005 and August 2008 in our center. Before treatment, each patient underwent enhanced magnetic resonance imaging of the nasopharynx and neck. Patients with negative cervical lymph nodes received radiotherapy to the nasopharynx, skull base and upper neck drainage areas, while patients with cervical lymph node involvement received treatment to the whole neck. The prescription doses were 66-70.4 Gy/30-32 fractions to the gross tumor volume of nasopharynx, 66 Gy to the positive neck nodes, 60 Gy to the high-risk clinical target volume and 54 Gy to the low-risk clinical target volume. Patients staged III, IV A/B or II also received chemotherapy. The median follow-up of these 120 patients was 54 months. The 5-year local control, regional control, distant metastasis-free and overall survival rates were 90.7, 96.5, 84.8 and 81.4 %, respectively. Four patients suffered regional recurrence: 2, 1 and 1 experienced regional recurrence in level II, retropharyngeal and parotid lymph nodes, respectively. In nasopharyngeal carcinoma patients with negative level Ib lymph nodes who are treated with level Ib-sparing IMRT, regional lymph node recurrence alone is rare. Therefore, sparing level Ib lymph nodes by IMRT is feasible in selected patients.

  1. DEMAT: A multi-institutional dosimetry audit of rotational and static intensity-modulated radiotherapy.

    Science.gov (United States)

    Lafond, Caroline; Chiavassa, Sophie; Bertaut, Cindy; Boussion, Nicolas; Chapel, Nathalie; Chapron, Lucie; Coste, Frédéric; Crespin, Sylvain; Dy, Gilles; Faye, Papa Abdoulaye; Leleu, Cyril; Bouvier, Jeanne; Madec, Ludovic; Mesgouez, Jérôme; Palisson, Jérémy; Vela, Anthony; Delpon, Grégory

    2016-05-01

    Static beam intensity-modulated-radiation-therapy (IMRT) and/or Volumetric-Modulated-Arc-Therapy (VMAT) are now available in many regional radiotherapy departments. The aim of this multi-institutional audit was to design a new methodology based on radiochromic films to perform an independent quality control. A set of data were sent to all participating centres for two clinical localizations: prostate and Head and Neck (H&N) cancers. The agreement between calculations and measurements was verified in the Octavius phantom (PTW) by point measurements using ionization chambers and by 2D measurements using EBT3 radiochromic films. Due to uncertainties in the whole procedure, criteria were set to 5% and 3% in local dose and 3mm in distance excluding doses lower than 10% of the maximum doses. No normalization point or area was used for the quantitative analysis. 13 radiotherapy centres participated in this audit involving 28 plans (12 IMRT, 16 VMAT). For point measurements, mean errors were -0.18±1.54% and 0.00±1.58% for prostate and H&N cases respectively. For 2D measurements with 5%/3mm criteria, gamma map analysis showed a pixel pass rate higher than 95% for prostate and H&N. Mean gamma index was lower than 0.4 for prostate and 0.5 for H&N. Both techniques yielded similar results. This study showed the feasibility of an independent quality control by peers for conventional IMRT and VMAT. Results from all participating centres were found to be in good agreement. This regional study demonstrated the feasibility of our new methodology based on radiochromic films without dose normalization on a specific point. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  2. Efficacy and prognostic factors of intensity-modulated radiotherapy for large primary hepatocellular carcinoma

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    FANG Ziyan

    2015-06-01

    Full Text Available ObjectiveTo investigate the efficacy of intensity-modulated radiotherapy (IMRT in treating large primary hepatocellular carcinoma (LHCC which is unsuitable for surgery or has poor response to radiofrequency ablation, interventional therapy, and other local treatments, and to identify the prognostic factors for survival. MethodsWe retrospectively analyzed the clinical data of 29 LHCC patients who received IMRT from April 2008 to August 2011. There were five fractions per week and the dose for each fraction was 2 to 6 Gy; the total dose was 50 to 70 Gy. The short-term efficacy and prognosis were observed and analyzed. The Kaplan-Meier method was used to calculate survival rates and the log-rank test was used for survival difference analysis. Multivariate analysis was performed using the Cox regression model. ResultsThe complete remission, partial remission, stable disease, and disease progression rates were 3.57%, 32.14%, 53.57%, and 10.72%, respectively. The overall median progression-free survival (PFS time was 6.43 months, and the median overall survival (OS time was 11.43 months. The 1- and 2-year survival rates were 46.79% and 25.23%, respectively. Univariate analysis showed tumor response rate was an independent prognostic factor for PFS. The Cox proportional hazard model suggested the tumor response rate and prescribed dose were the independent prognostic factors for PFS. In addition, the independent prognostic factors for OS included tumor response rate, tumor diameter, and tumor volume. The common acute radiotherapy toxicities included gastrointestinal discomfort, radiation-induced liver damage, and myelosuppression. ConclusionIMRT is a safe and effective option for the LHCC patients who are unsuitable for surgery or in the cases that other local therapies fail.

  3. Patterns of relapse following surgery and postoperative intensity modulated radiotherapy for oral and oropharyngeal cancer

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    Collan, Juhani; Vaalavirta, Leila; Kajanti, Mikael; Tenhunen, Mikko; Saarilahti, Kauko (Dept. of Oncology, Helsinki Univ. Central Hospital, and Univ. of Helsinki, Helsinki (Finland)), E-mail: kauko.saarilahti@hus.fi; Lundberg, Marie; Baeck, Leif; Maekitie, Antti (Dept. of Otorhinolaryngology - Head and Neck Surgery, Helsinki Univ. Central Hospital, and Univ. of Helsinki, Helsinki (Finland))

    2011-10-15

    Background. To investigate the patterns of relapse following intensity modulated radiotherapy (IMRT) given after radical surgery for oral and oropharyngeal squamous cell cancer. Patients and methods. One hundred and two patients with oral or oropharyngeal cancer were treated with radical surgery followed by IMRT up to a mean total dose of 60 Gy between years 2001 and 2007. Thirty-nine of the patients (%) also received concomitant weekly cisplatin. Forty of the patients had oral and 62 had oropharyngeal cancer. Data on the tumour, patient and treatment factors were collected. Following therapy the patients were followed by clinical examination, endoscopy and MRI/CT at 2- to 3-months interval up to 2 years and thereafter at 6-month intervals. Results. The mean follow-up time of the patients was 55 months (range, 26-106 months). The rate for local tumour control for the whole cohort was 92.2%: 87.5% for oral cancer patients and 96.7% for oropharyngeal cancer patients. The 5-year disease specific survival was 90.2% and 5-year overall survival 84.3%. During the follow-up eight locoregional recurrences were observed, three at the primary tumour site and one at regional nodal site and four at both sites. The mean time to primary tumour recurrence was seven months (range, 2-10 months) and to nodal recurrence seven months (range, 2-12 months). Distant metastasis occurred in six (6%) patients. The factors associated with poor prognosis were the primary tumour size and tumour site with oral cancers having worse outcome. The treatment was well tolerated with no unexpected toxicities. The most frequent late toxicity was dysphagia necessitating permanent PEG in five patients. This was correlated with the advanced primary tumour size and resulting in wide tumour excision and reconstruction. Conclusions. Surgery combined with postoperative radiotherapy given as IMRT results in low level of tumour recurrence

  4. Intensity modulated whole pelvic radiotherapy in patients with cervix cancer: analysis of acute toxicity

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    Choi, Young Min; Lee, Hyung Sik; Hur, Won Joo; Cha, Moon Seok; Kim, Hyun Ho [School of Medicine, Dong-A University, Busan (Korea, Republic of)

    2006-12-15

    To evaluate acute toxicities in cervix cancer patients receiving intensity modulated whole pelvic radiation therapy (IM-WPRT). Between August 2004 and April 2006, 17 patients who underwent IM-WPRT were analysed. An intravenous contrast agent was used for radiotherapy planning computed tomography (CT). The central clinical target volume (CTV) included the primary tumor, uterus, vagina, and parametrium. The nodal CTV was defined as the lymph nodes larger than 1 cm seen on CT and the contrased-enhanced pelvic vessels. The planning target volume (PTV) was the 1-cm expanded volume around the central CTV, except for a 5-mm expansion from the posterior vagina, and the nodal PTV was defined as the nodal CTV plus a 1.5 cm margin. IM-WPRT was prescribed to deliver a dose of 50 Gy to more than 95% of the PTV. Acute toxicity was assessed with common toxicity criteria up to 60 days after radiotherapy. Grade 1 nausea developed in 10 (58.9%) patients, and grade 1 and 2 diarrhea developed in 11 (64.7%) and 1 (5.9%) patients, respectively. No grade 3 or higher gastrointestinal toxicity was seen. Leukopenia, anemia, and thrombocytopenia occurred in 15 (88.2%). 7 (41.2%), and 2 (11.8%) patients, respectively, as hematologic toxicities. Grade 3 leukopenia developed in 2 patients who were treated with concurrent chemoradiotherapy. IM-WPRT can be a useful treatment for cervix cancer patients with decreased severe acute toxicities and a resultant improved compliance to whole pelvic irradiation.

  5. Toxicity after intensity-modulated, image-guided radiotherapy for prostate cancer

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    Flentje, Michael [Dept. of Radiotherapy, Univ. Hospital Wuerzburg (Germany); Guckenberger, Matthias; Ok, Sami; Polat, Buelent; Sweeney, Reinhart A.

    2010-10-15

    Purpose: To evaluate toxicity after dose-escalated radiotherapy for prostate cancer using intensity-modulated treatment planning (IMRT) and image-guided treatment (IGRT) delivery. Patients and Methods: 100 patients were treated with simultaneous integrated boost (SIB) IMRT for prostate cancer: doses of 76.23 Gy and 60 Gy in 33 fractions were prescribed to the prostate and the seminal vesicles, respectively, for intermediate- and high-risk patients (n = 74). The total dose was 73.91 Gy in 32 fractions for low-risk patients and after transurethral resection of the prostate (n = 26). The pelvic lymphatics were treated with 46 Gy in 25 fractions in patients with high risk of lymph node metastases using an SIB to the prostate (n = 25). IGRT was practiced with cone-beam computed tomography. Acute and late gastrointestinal (GI) and genitourinary (GU) toxicity was evaluated prospectively (CTCAE v3.0). Results: Treatment was completed as planned by all patients. Acute GI and GU toxicity grade {>=} 2 was observed in 12% and 42% of the patients, respectively, with 4% suffering from GU toxicity grade 3. 6 weeks after treatment, the incidence of acute toxicity grade {>=} 2 had decreased to 12%. With a median follow-up of 26 months, late GI and GU toxicity grade {>=} 2 was seen in 1.5% and 7.7% of the patients at 24 months. Four patients developed late toxicity grade 3 (GI n = 1; GU n = 3). Presence of acute GI and GU toxicity was significantly associated with late GI (p = 0.0007) and GU toxicity (p = 0.006). Conclusion: High-dose radiotherapy for prostate cancer using IMRT and IGRT resulted in low rates of acute toxicity and preliminary results of late toxicity are promising. (orig.)

  6. Intensity modulated radiotherapy with concurrent chemotherapy for larynx preservation of advanced resectable hypopharyngeal cancer

    Directory of Open Access Journals (Sweden)

    Chao Hsing-Lung

    2010-05-01

    Full Text Available Abstract Background To analyze the rate of larynx preservation in patients of locally advanced hypopharyngeal cancer treated with intensity modulated radiotherapy (IMRT plus concurrent chemotherapy, and compare the results with patients treated with primary surgery. Methods Between January 2003 and November 2007, 14 patients were treated with primary surgery and 33 patients were treated with concurrent chemoradiotherapy (CCRT using IMRT technique. Survival rate, larynx preservation rate were calculated with the Kaplan-Meier method. Multivariate analysis was conducted for significant prognostic factors with Cox-regression method. Results The median follow-up was 19.4 months for all patients, and 25.8 months for those alive. The 5-year overall survival rate was 33% and 44% for primary surgery and definitive CCRT, respectively (p = 0.788. The 5-year functional larynx-preservation survival after IMRT was 40%. Acute toxicities were common, but usually tolerable. The rates of treatment-related mucositis (≥ grade 2 and pharyngitis (≥ grade 3 were higher in the CCRT group. For multivariate analysis, treatment response and cricoid cartilage invasion strongly correlated with survival. Conclusions IMRT plus concurrent chemotherapy may preserve the larynx without compromising survival. Further studies on new effective therapeutic agents are essential.

  7. Improved planning time and plan quality through multicriteria optimization for intensity-modulated radiotherapy.

    Science.gov (United States)

    Craft, David L; Hong, Theodore S; Shih, Helen A; Bortfeld, Thomas R

    2012-01-01

    To test whether multicriteria optimization (MCO) can reduce treatment planning time and improve plan quality in intensity-modulated radiotherapy (IMRT). Ten IMRT patients (5 with glioblastoma and 5 with locally advanced pancreatic cancers) were logged during the standard treatment planning procedure currently in use at Massachusetts General Hospital (MGH). Planning durations and other relevant planning information were recorded. In parallel, the patients were planned using an MCO planning system, and similar planning time data were collected. The patients were treated with the standard plan, but each MCO plan was also approved by the physicians. Plans were then blindly reviewed 3 weeks after planning by the treating physician. In all cases, the treatment planning time was vastly shorter for the MCO planning (average MCO treatment planning time was 12 min; average standard planning time was 135 min). The physician involvement time in the planning process increased from an average of 4.8 min for the standard process to 8.6 min for the MCO process. In all cases, the MCO plan was blindly identified as the superior plan. This provides the first concrete evidence that MCO-based planning is superior in terms of both planning efficiency and dose distribution quality compared with the current trial and error-based IMRT planning approach. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Dosimetric studies of cadmium free alloy used in compensator based intensity modulated radiotherapy

    Science.gov (United States)

    Kaushik, Sandeep; Punia, Rajesh; Tyagi, Atul; Singh, Mann P.

    2017-10-01

    Aim of this study was to investigate dosimetric properties of cadmium free alloy which is used in compensator based intensity modulated radiotherapy (cIMRT). A mixture of lead, bismuth and tin was used to prepare the alloy whose melting point is 90-95 °C. Slabs of different thicknesses ranging from 0.71 cm to 6.14 cm were prepared. Density of alloy was measured by Archimedes' principle using water. For six megavolt (6 MV) photon beam energy transmission, linear effective attenuation coefficient (μeff), tissue phantom ratio (TPR1020), beam hardening, surface dose (Ds), percentage depth dose (PDD) and effect of scatter has been measured and analyzed for different field sizes and different thickness of compensator. Effect of extended source to detector distance (SDD) on transmissions and μeff was measured. The density of alloy was found to be 9.5456 g/cm3. At SDD of 100 cm, μeff was observed 0.4253 cm-1 for a field size of 10×10 cm 2. Calculated TPR1020 was found to be within 3% of experimental TPR1020 . It was found to be increasing with increasing thickness of compensator. Ds was found to decrease with thickness of compensator and increase with wider collimator opening due to increased scattered dose. Compensator slabs of 1 cm, 1.98 cm and 4.16 cm decreased surface dose by 4.2%, 6.1% and 9.5% respectively for a field size of 10×10 cm2 at 100 cm SDD. For small field size of 3×3 cm2 and 5×5 cm2 PDDs are increased from 3.0% to 5.5% of open beam PDDs as compensator thickness increased from 1 cm to 6.14 cm at a depth of 10 cm in water while variation in PDD is insignificant in for larger field sizes 10×10 cm2 to 20×20 cm2. A high degree of intensity modulation is essential in cIMRT and it can be achieved with this compensator material. Dosimetric properties analyzed in this study establish this alloy as a reliable, reusable, optimally dense and cost effective compensator material.

  9. Correcting radiation survey data to account for increased leakage during intensity modulated radiotherapy treatments

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    Kairn, T. [Premion Cancer Care, Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower Qld 4066, Australia and Science and Engineering Faculty, Queensland University of Technology, G.P.O. Box 2434, Brisbane Qld 4000 (Australia); Crowe, S. B.; Trapp, J. V. [Science and Engineering Faculty, Queensland University of Technology, G.P.O. Box 2434, Brisbane Qld 4000 (Australia)

    2013-11-15

    Purpose: Intensity modulated radiotherapy (IMRT) treatments require more beam-on time and produce more linac head leakage to deliver similar doses to conventional, unmodulated, radiotherapy treatments. It is necessary to take this increased leakage into account when evaluating the results of radiation surveys around bunkers that are, or will be, used for IMRT. The recommended procedure of applying a monitor-unit based workload correction factor to secondary barrier survey measurements, to account for this increased leakage when evaluating radiation survey measurements around IMRT bunkers, can lead to potentially costly overestimation of the required barrier thickness. This study aims to provide initial guidance on the validity of reducing the value of the correction factor when applied to different radiation barriers (primary barriers, doors, maze walls, and other walls) by evaluating three different bunker designs.Methods: Radiation survey measurements of primary, scattered, and leakage radiation were obtained at each of five survey points around each of three different radiotherapy bunkers and the contribution of leakage to the total measured radiation dose at each point was evaluated. Measurements at each survey point were made with the linac gantry set to 12 equidistant positions from 0° to 330°, to assess the effects of radiation beam direction on the results.Results: For all three bunker designs, less than 0.5% of dose measured at and alongside the primary barriers, less than 25% of the dose measured outside the bunker doors and up to 100% of the dose measured outside other secondary barriers was found to be caused by linac head leakage.Conclusions: Results of this study suggest that IMRT workload corrections are unnecessary, for survey measurements made at and alongside primary barriers. Use of reduced IMRT workload correction factors is recommended when evaluating survey measurements around a bunker door, provided that a subset of the measurements used in

  10. Toxicity after post-prostatectomy image-guided intensity-modulated radiotherapy using Australian guidelines.

    Science.gov (United States)

    Chin, Stephen; Aherne, Noel J; Last, Andrew; Assareh, Hassan; Shakespeare, Thomas P

    2017-06-17

    We evaluated single institution toxicity outcomes after post-prostatectomy radiotherapy (PPRT) via image-guided intensity-modulated radiation therapy (IG-IMRT) with implanted fiducial markers following national eviQ guidelines, for which late toxicity outcomes have not been published. Prospectively collected toxicity data were retrospectively reviewed for 293 men who underwent 64-66 Gy IG-IMRT to the prostate bed between 2007 and 2015. Median follow-up after PPRT was 39 months. Baseline grade ≥2 genitourinary (GU), gastrointestinal (GI) and sexual toxicities were 20.5%, 2.7% and 43.7%, respectively, reflecting ongoing toxicity after radical prostatectomy. Incidence of new (compared to baseline) acute grade ≥2 GU and GI toxicity was 5.8% and 10.6%, respectively. New late grade ≥2 GU, GI and sexual toxicity occurred in 19.1%, 4.7% and 20.2%, respectively. However, many patients also experienced improvements in toxicities. For this reason, prevalence of grade ≥2 GU, GI and sexual toxicities 4 years after PPRT was similar to or lower than baseline (21.7%, 2.6% and 17.4%, respectively). There were no grade ≥4 toxicities. Post-prostatectomy IG-IMRT using Australian contouring guidelines appears to have tolerable acute and late toxicity. The 4-year prevalence of grade ≥2 GU and GI toxicity was virtually unchanged compared to baseline, and sexual toxicity improved over baseline. This should reassure radiation oncologists following these guidelines. Late toxicity rates of surgery and PPRT are higher than following definitive IG-IMRT, and this should be taken into account if patients are considering surgery and likely to require PPRT. © 2017 The Royal Australian and New Zealand College of Radiologists.

  11. Dosimetric comparison using different multileaf collimeters in intensity-modulated radiotherapy for upper thoracic esophageal cancer

    Directory of Open Access Journals (Sweden)

    Fu Yuchuan

    2010-07-01

    Full Text Available Abstract Purpose To study the impacts of multileaf collimators (MLC width [standard MLC width of 10 mm (sMLC and micro-MLC width of 4 mm (mMLC] in the intensity-modulated radiotherapy (IMRT planning for the upper thoracic esophageal cancer (UTEC. Methods and materials 10 patients with UTEC were retrospectively planned with the sMLC and the mMLC. The monitor unites (MUs and dose volume histogram-based parameters [conformity index (CI and homogeneous index (HI] were compared between the IMRT plans with sMLC and with mMLC. Results The IMRT plans with the mMLC were more efficient (average MUs: 703.1 ± 68.3 than plans with the sMLC (average MUs: 833.4 ± 73.8 (p p 5 (3260.3 ± 374.0 vs 3404.5 ± 374.4/gEUD (1815.1 ± 281.7 vs 1849.2 ± 297.6 of the spinal cord, the V10 (33.2 ± 6.5 vs 34.0 ± 6.7, V20 (16.0 ± 4.6 vs 16.6 ± 4.7, MLD (866.2 ± 174.1 vs 887.9 ± 172.1 and gEUD (938.6 ± 175.2 vs 956.8 ± 171.0 of the lungs were observed in the plans with the mMLC, respectively (p Conclusions Comparing to the sMLC, the mMLC not only demonstrated higher efficiencies and more optimal target coverage, but also considerably improved the dose sparing of OARs in the IMRT planning for UTEC.

  12. Outcomes After Intensity-Modulated Versus Conformal Radiotherapy in Older Men With Nonmetastatic Prostate Cancer

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    Bekelman, Justin E., E-mail: bekelman@uphs.upenn.edu [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); Mitra, Nandita [Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Efstathiou, Jason [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Liao Kaijun [Division of General Internal Medicine, University of Pennsylvania, Philadelphia, PA (United States); Sunderland, Robert; Yeboa, Deborah N. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Armstrong, Katrina [Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA (United States); Division of General Internal Medicine, 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)

    2011-11-15

    Purpose: There is little evidence comparing complications after intensity-modulated (IMRT) vs. three-dimensional conformal radiotherapy (CRT) for prostate cancer. The study objective was to test the hypothesis that IMRT, compared with CRT, is associated with a reduction in bowel, urinary, and erectile complications in elderly men with nonmetastatic prostate cancer. Methods and Materials: We undertook an observational cohort study using registry and administrative claims data from the SEER-Medicare database. We identified men aged 65 years or older diagnosed with nonmetastatic prostate cancer in the United States between 2002 and 2004 who received IMRT (n = 5,845) or CRT (n = 6,753). The primary outcome was a composite measure of bowel complications. Secondary outcomes were composite measures of urinary and erectile complications. We also examined specific subsets of bowel (proctitis/hemorrhage) and urinary (cystitis/hematuria) events within the composite complication measures. Results: IMRT was associated with reductions in composite bowel complications (24-month cumulative incidence 18.8% vs. 22.5%; hazard ratio [HR] 0.86; 95% confidence interval [CI], 0.79-0.93) and proctitis/hemorrhage (HR 0.78; 95% CI, 0.64-0.95). IMRT was not associated with rates of composite urinary complications (HR 0.93; 95% CI, 0.83-1.04) or cystitis/hematuria (HR 0.94; 95% CI, 0.83-1.07). The incidence of erectile complications involving invasive procedures was low and did not differ significantly between groups, although IMRT was associated with an increase in new diagnoses of impotence (HR 1.27, 95% CI, 1.14-1.42). Conclusion: IMRT is associated with a small reduction in composite bowel complications and proctitis/hemorrhage compared with CRT in elderly men with nonmetastatic prostate cancer.

  13. Whole pelvic intensity-modulated radiotherapy for high-risk prostate cancer: a preliminary report

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    Joo, Ji Hyeon; Kim, Yeon Joo; Kim, Young Seok [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); and others

    2013-12-15

    To assess the clinical efficacy and toxicity of whole pelvic intensity-modulated radiotherapy (WP-IMRT) for high-risk prostate cancer. Patients with high-risk prostate cancer treated between 2008 and 2013 were reviewed. The study included patients who had undergone WP-IMRT with image guidance using electronic portal imaging devices and/or cone-beam computed tomography. The endorectal balloon was used in 93% of patients. Patients received either 46 Gy to the whole pelvis plus a boost of up to 76 Gy to the prostate in 2 Gy daily fractions, or 44 Gy to the whole pelvis plus a boost of up to 72.6 Gy to the prostate in 2.2 Gy fractions. The study cohort included 70 patients, of whom 55 (78%) had a Gleason score of 8 to 10 and 50 (71%) had a prostate-specific antigen level > 20 ng/mL. The androgen deprivation therapy was combined in 62 patients. The biochemical failure-free survival rate was 86.7% at 2 years. Acute any grade gastrointestinal (GI) and genitourinary (GU) toxicity rates were 47% and 73%, respectively. The actuarial rate of late grade 2 or worse toxicity at 2 years was 12.9% for GI, and 5.7% for GU with no late grade 4 toxicity. WP-IMRT was well tolerated with no severe acute or late toxicities, resulting in at least similar biochemical control to that of the historic control group with a small field. The long-term efficacy and toxicity will be assessed in the future, and a prospective randomized trial is needed to verify these findings.

  14. Carotid sparing intensity modulated radiotherapy on early glottic cancer: Preliminary study

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    Choi, Hoon Sik; Jeong, Bae Kwon; Jeong, Ho Jin; Song, Jin Ho; Kim, Jin Pyeong; Park, Jung Je; Woo, Seung Hoon; Kang, Ki Mun [Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju (Korea, Republic of)

    2016-03-15

    To compare the dose distribution between carotid sparing intensity modulated radiotherapy (IMRT) and opposed lateral field technique (LAFT), and to determine the effects of carotid sparing IMRT in early glottic cancer patients who have risk factors for atherosclerosis. Ten early glottic cancer patients were treated with carotid sparing IMRT. For each patient, the conventional LAFT plan was developed for comparison. IMRT and LAFT plans were compared in terms of planning target volume (PTV) coverage, conformity index, homogeneity index, and the doses to planning organ at risk volume (PRV) for carotid arteries, spinal cord and pharyngeal constrictor muscle. Recurrence was not observed in any patients during the follow-up period. V95% for PTV showed no significant difference between IMRT and LAFT plans, while V100% was significantly higher in the IMRT plan (95.5% vs. 94.6%, p = 0.005). The homogeneity index (11.6%) and conformity index (1.4) in the IMRT plan were significantly better than those in the LAFT plans (8.5% and 5.1, respectively) (p = 0.005). The median V5Gy (90.0%), V25Gy (13.5%), and V50Gy (0%) for carotid artery PRV in the IMRT plan were significantly lower than those in the LAFT plan (99.1%, 89.0%, and 77.3%, respectively) (p = 0.005). Our study suggests that carotid sparing IMRT can significantly decrease the dose to carotid arteries compared to LAFT, and it would be considered for early glottic cancer patient with high risk of atherosclerosis.

  15. Intensity modulated radiotherapy versus volumetric modulated arc therapy in breast cancer: A comparative dosimetric analysis

    Directory of Open Access Journals (Sweden)

    KR Muralidhar

    2015-01-01

    Full Text Available Purpose: Intensity modulated radiotherapy (IMRT and volumetric modulated arc therapy (VMAT has the capacity to optimize the dose distribution. We analyzed the dosimetric differences of plans in treatment planning system (TPS between VMAT and IMRT in treating breast cancer. Methods: Fourteen patients were simulated, planned, and treated with VMAT using single, double or partial arcs. IMRT treatments were generated using 4 to 5 tangential IMRT fields for the same patients. All treatment plans were planned for 50 Gy in 25 fractions. The VMAT and IMRT plans were compared using the planning target volume (PTV dose and doses to the other organs at risk (OARs. Results: For the PTV, comparable minimum, mean, maximum, median, and modal dose as well equivalent sphere diameter of the structure (Equis were observed between VMAT and IMRT plans and found that these values were significantly equal in both techniques. The right lung mean and modal doses were considerably higher in VMAT plans while maximum value was considerably lower when compared with IMRT plans. The left lung mean and modal doses were higher with VMAT while maximum doses were higher in IMRT plans. The mean dose to the heart and maximum dose to the spinal cord was lower with IMRT. The mean dose to the body was higher in VMAT plans while the maximum dose was higher in IMRT plans. Conclusion: Four field tangential IMRT delivered comparable PTV dose with generally less dose to normal tissues in our breast cancer treatment study. The IMRT plans typically had more favourable dose characteristics to the lung, heart, and spinal cord and body dose when compared with VMAT. The only minor advantage of VMAT for breast cases was slightly better PTV coverage.

  16. Duplicating a tandem and ovoids distribution with intensity-modulated radiotherapy: a feasibility study.

    Science.gov (United States)

    Malhotra, Harish K; Avadhani, Jaiteerth S; deBoer, Steven F; Jaggernauth, Wainwright; Kuettel, Michael R; Podgorsak, Matthew B

    2007-07-17

    Brachytherapy plays an important role in the definitive treatment of cervical cancers by radiotherapy. In the present study, we investigated whether sliding-window intensity-modulated radiation therapy (IMRT) can achieve a pear-shaped distribution with a similar sharp dose falloff identical to that of brachytherapy. The computed tomography scans of a tandem and ovoid patient were pushed to both a high dose rate (HDR) and an IMRT treatment planning system (TPS) after the rectum, bladder, and left and right femoral heads had been outlined, ensuring identical structures in both planning systems. A conventional plan (7 Gy in 5 fractions, defined as the average dose to the left and right point A) was generated for HDR treatment. The 150%, 125%, 100%, 75%, 50%, and 25% isodose curves were drawn on each slice and then transferred to the IMRT TPS. The 100% isodose envelope from the HDR plan was the target for IMRT planning. A 7-field IMRT plan using 6-MV X-ray beams was generated and compared with the HDR plan using isodose conformity to the target and 125% volume, dose-volume histograms, and integral dose. The resulting isodose distribution demonstrated good agreement between the HDR and IMRT plans in the 100% and 125% isodose range. The dose falloff in the HDR plan was much steeper than that in the IMRT plan, but it also had a substantially higher maximum dose. Integral dose for the target, rectum, and bladder were found to be 6.69 J, 1.07 J, and 1.02 J in the HDR plan; the respective values for IMRT were 3.47 J, 1.79 J, and 1.34 J. Our preliminary results indicate that the HDR dose distribution can be replicated using a standard sliding-window IMRT dose delivery technique for points lying closer to the three-dimensional isodose envelope surrounding point A. Differences in radiobiology and patient positioning between the two techniques merit further consideration.

  17. The impact of intensity modulated radiotherapy on the skin dose for deep seated tumors

    Institute of Scientific and Technical Information of China (English)

    H. S. Abou-Elenein; Ehab M. Attalla; Hany Ammar; Ismail Eldesoky; Mohamed Farouk; Shaimaa Shoer

    2013-01-01

    Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate the skin dose calculation accuracy of the XIO 4.04 treatment planning system. Methods: More investigations for the influences of IMRT on skin doses would increase its applications for many treatment sites. Measuring skin doses in real treatment situations would reduce the uncertainty of skin dose prediction. In this work a pediatric human phantom was covered by a layer of 1 mm bolus at three treatment sites and thermoluminescent dosimeter (TLD) chips were inserted into the bolus at each treatment site before CT scan. Two different treatment plans [three-dimensional conformal radiation therapy (3DCRT) and IMRT] for each treatment sites were performed on XIO 4.04 treatment planning system using superposition algorism. Results: The results showed that the surface doses for 3DCRT were higher than the surface doses in IMRT by 1.6%, 2.5% and 3.2% for brain, abdomen and pelvis sites respectively. There was good agreement between measured and calculated surface doses, where the calculated surface dose was 15.5% for brain tumor calculated with 3DCRT whereas the measured surface dose was 12.1%. For abdomen site the calculated surface dose for IMRT treatment plan was 16.5% whereas the measured surface dose was 12.6%. Conclusion: The skin dose in IMRT for deep seated tumors is lower than that in 3DCRT which is another advantage for the IMRT. The TLD readings showed that the difference between the calculated and measured point dose is negligible. The superposition calculation algorism of the XIO 4.04 treatment planning system modeled the superficial dose well.

  18. The inaugural Frank Ellis Lecture--latrogenic cancer: the impact of intensity-modulated radiotherapy.

    Science.gov (United States)

    Hall, E J

    2006-05-01

    It is an honour and personal pleasure to give the inaugural Frank Ellis Lecture to celebrate his 100th birthday, and to acknowledge his enormous contributions to radiation oncology. Intensity-modulated radiotherapy (IMRT) allows dose to be concentrated in the tumour volume while sparing normal tissues. However, the downside to IMRT is the potential to increase the number of radiation-induced second cancers because more fields are used which involves a bigger volume of normal tissue exposed to lower doses. It has been estimated that IMRT may double the incidence of solid cancers in long-term survivors. This may be acceptable in older patients if balanced by an improvement in local tumour control and reduced toxicity. On the other hand, the incidence of second cancers is higher in children, so that doubling it may not be acceptable. IMRT represents a special case for children. First, they are more sensitive to radiation-induced cancer than adults. Second, radiation scattered from the treatment volume is more important in the small body of the child. Third, there is the question of genetic susceptibility, as many childhood cancers involve a germline mutation. The levels of leakage radiation in current Linacs can be reduced, but the cost would be substantial. An alternative strategy is to replace X-rays with protons. This is an advantage only if the proton machine uses a pencil scanning beam, as passive modulation of a scattering foil produces neutrons, which results in an effective dose to the patient higher than that characteristic of IMRT.

  19. Dosimetric validation of new semiconductor diode dosimetry system for intensity modulated radiotherapy

    Directory of Open Access Journals (Sweden)

    Rajesh Kinhikar

    2012-01-01

    Full Text Available Introduction: The new diode Isorad was validated for intensity modulated radiotherapy (IMRT and the observations during the validation are reported. Materials and Methods: The validation includes intrinsic precision, post-irradiation stability, dose linearity, dose-rate effect, angular response, source to surface (SSD dependence, field size dependence, and dose calibration. Results: The intrinsic precision of the diode was more than 1% (1 σ. The linearity found in the whole range of dose analyzed was 1.93% (R 2 = 1. The minimum and maximum variation in the measured and calculated dose were found to be 0.78% (with 25 MU at ioscentre and 4.8% (with 1000 MU at isocentre, respectively. The maximal variation in angular response with respect to arbitrary angle 0° found was 1.31%. The diode exhibited a 51.7% and 35% decrease in the response in the 35 cm and 20 cm SSD range, respectively. The minimum and the maximum variation in the measured dose from the diode and calculated dose were 0.82% (5 cm × 5 cm and 3.75% (30 cm × 30 cm, respectively. At couch 270°, the response of the diode was found to vary maximum by 1.4% with ΁ 60 gantry angle. Mean variation between measured dose with diode and planned dose by TPS was found to be 1.3% (SD 0.75 for IMRT patient-specific quality assurance. Conclusion: For the evaluation of IMRT, use of cylindrical diode is strongly recommended.

  20. Interfractional variability in intensity-modulated radiotherapy of prostate cancer with or without thermoplastic pelvic immobilization

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    Lee, J.A.; Kim, C.Y.; Park, Y.J.; Yoon, W.S.; Lee, N.K.; Yang, D.S. [Korea University Guro Hospital, Korea University College of Medicine, Department of Radiation Oncology, Seoul (Korea, Republic of)

    2014-01-15

    To determine the variability of patient positioning errors associated with intensity-modulated radiotherapy (IMRT) for prostate cancer and to assess the impact of thermoplastic pelvic immobilization on these errors using kilovoltage (kV) cone-beam computed tomography (CBCT). From February 2012 to June 2012, the records of 314 IMRT sessions in 19 patients with prostate cancer, performed with or without immobilization at two different facilities in the Korea University Hospital were analyzed. The kV CBCT images were matched to simulation computed tomography (CT) images to determine the simulation-to-treatment variability. The shifts along the x (lateral)-, y (longitudinal)- and z (vertical)-axes were measured, as was the shift in the three dimensional (3D) vector. The measured systematic errors in the immobilized group during treatment were 0.46 ± 1.75 mm along the x-axis, - 0.35 ± 3.83 mm along the y-axis, 0.20 ± 2.75 mm along the z-axis and 4.05 ± 3.02 mm in the 3D vector. Those of nonimmobilized group were - 1.45 ± 7.50 mm along the x-axis, 1.89 ± 5.07 mm along the y-axis, 0.28 ± 3.81 mm along the z-axis and 8.90 ± 4.79 mm in the 3D vector. The group immobilized with pelvic thermoplastics showed reduced interfractional variability along the x- and y-axes and in the 3D vector compared to the nonimmobilized group (p < 0.05). IMRT with thermoplastic pelvic immobilization in patients with prostate cancer appears to be useful in stabilizing interfractional variability during the planned treatment course. (orig.)

  1. Comparison of intensity-modulated tomotherapy with stereotactically guided conformal radiotherapy for brain tumors.

    Science.gov (United States)

    Khoo, V S; Oldham, M; Adams, E J; Bedford, J L; Webb, S; Brada, M

    1999-09-01

    Intensity-modulated radiotherapy (IMRT) offers the potential to more closely conform dose distributions to the target, and spare organs at risk (OAR). Its clinical value is still being defined. The present study aims to compare IMRT with stereotactically guided conformal radiotherapy (SCRT) for patients with medium size convex-shaped brain tumors. Five patients planned with SCRT were replanned with the IMRT-tomotherapy method using the Peacock system (Nomos Corporation). The planning target volume (PTV) and relevant OAR were assessed, and compared relative to SCRT plans using dose statistics, dose-volume histograms (DVH), and the Radiation Therapy Oncology Group (RTOG) stereotactic radiosurgery criteria. The median and mean PTV were 78 cm3 and 85 cm3 respectively (range 62-119 cm3). The differences in PTV doses for the whole group (Peacock-SCRT +/-1 SD) were 2%+/-1.8 (minimum PTV), and 0.1%+/-1.9 (maximum PTV). The PTV homogeneity achieved by Peacock was 12.1%+/-1.7 compared to 13.9%+/-1.3 with SCRT. Using RTOG guidelines, Peacock plans provided acceptable PTV coverage for all 5/5 plans compared to minor coverage deviations in 4/5 SCRT plans; acceptable homogeneity index for both plans (Peacock = 1.1 vs. SCRT = 1.2); and comparable conformity index (1.4 each). As a consequence of the transaxial method of arc delivery, the optic nerves received mean and maximum doses that were 11.1 to 11.6%, and 10.3 to 15.2% higher respectively with Peacock plan. The maximum optic lens, and brainstem dose were 3.1 to 4.8% higher, and 0.6% lower respectively with Peacock plan. However, all doses remained below the tolerance threshold (5 Gy for lens, and 50 Gy for optic nerves) and were clinically acceptable. The Peacock method provided improved PTV coverage, albeit small, in this group of convex tumors. Although the OAR doses were higher using the Peacock plans, all doses remained within the clinically defined threshold and were clinically acceptable. Further improvements may be

  2. Effect of intensity-modulated radiotherapy versus three-dimensional conformal radiotherapy on clinical outcomes in patients with glioblastoma multiforme

    Institute of Scientific and Technical Information of China (English)

    CHEN Yi-dong; FENG Jin; FANG Tong; YANG Ming; QIU Xiao-guang; JIANG Tao

    2013-01-01

    Background Few studies were reported on the comparison of clinical outcomes between intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) in the treatment of glioblastoma multiforme (GBM).This study aimed to determine whether IMRT improves clinical outcomes compared with 3D-CRT in patients with GBM.Methods The records of 54 patients with newly-diagnosed GBM from July 2009 to December 2010 were reviewed.The patients underwent postoperative IMRT or 3D-CRT with concurrent and adjuvant temozolomide.Kaplan-Meier method and log rank test were used to estimate differences of patients' survival.Results The median follow-up was 13 months.Of the 54 patients,fifty (92.6%) completed the combined modality treatment.The 1-year overall survival rate (OS) was 79.6%.The pattern of failure was predominantly local.A comparative analysis revealed that no statistical difference was observed between the IMRT group (n=21) and the 3D-CRT group (n=33) for 1-year OS (89.6% vs.75.8%,P=0.795),or 1-year progression-free survival (PFS) (61.0% vs.45.5%,P=0.867).In dosimetric comparison,IMRT seemed to allow better sparing of organs at risk than 3D-CRT did (P=0.050,P=0.055).However,there was no significant difference for toxicities of irradiation between the IMRT group and the 3D-CRT group.Conclusions Our preliminary results suggested that delivering standard radiation doses by IMRT is unlikely to improve local control or overall survival for GBM compared with 3D-CRT.Given this lack of survival benefit and increased costs of IMRT,the utilization of IMRT treatment for GBM needs to be carefully rationalized.

  3. Volumetric-Modulated Arc Therapy for Stereotactic Body Radiotherapy of Lung Tumors: A Comparison With Intensity-Modulated Radiotherapy Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Holt, Andrea; Vliet-Vroegindeweij, Corine van; Mans, Anton; Belderbos, Jose S. [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Damen, Eugene M.F., E-mail: e.damen@nki.nl [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

    2011-12-01

    Purpose: To demonstrate the potential of volumetric-modulated arc therapy (VMAT) compared with intensity-modulated radiotherapy (IMRT) techniques with a limited number of segments for stereotactic body radiotherapy (SBRT) for early-stage lung cancer. Methods and Materials: For a random selection of 27 patients eligible for SBRT, coplanar and noncoplanar IMRT and coplanar VMAT (using SmartArc) treatment plans were generated in Pinnacle{sup 3} and compared. In addition, film measurements were performed using an anthropomorphic phantom to evaluate the skin dose for the different treatment techniques. Results: Using VMAT, the delivery times could be reduced to an average of 6.6 min compared with 23.7 min with noncoplanar IMRT. The mean dose to the healthy lung was 4.1 Gy for VMAT and noncoplanar IMRT and 4.2 Gy for coplanar IMRT. The volume of healthy lung receiving >5 Gy and >20 Gy was 18.0% and 5.4% for VMAT, 18.5% and 5.0% for noncoplanar IMRT, and 19.4% and 5.7% for coplanar IMRT, respectively. The dose conformity at 100% and 50% of the prescribed dose of 54 Gy was 1.13 and 5.17 for VMAT, 1.11 and 4.80 for noncoplanar IMRT and 1.12 and 5.31 for coplanar IMRT, respectively. The measured skin doses were comparable for VMAT and noncoplanar IMRT and slightly greater for coplanar IMRT. Conclusions: Coplanar VMAT for SBRT for early-stage lung cancer achieved plan quality and skin dose levels comparable to those using noncoplanar IMRT and slightly better than those with coplanar IMRT. In addition, the delivery time could be reduced by {<=}70% with VMAT.

  4. Distant Metastases in Head-and-Neck Squamous Cell Carcinoma Treated With Intensity-Modulated Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yao Min, E-mail: min.yao@uhhospitals.org [Department of Radiation Oncology, University Hospitals Case Medical Center, Cleveland, OH (United States); Lu Minggen [School of Public Health, University of Nevada at Reno, Reno, NV (United States); Savvides, Panayiotis S. [Department of Medicine, University Hospitals Case Medical Center, Cleveland, OH (United States); Rezaee, Rod; Zender, Chad A.; Lavertu, Pierre [Department of Otolaryngology-Head and Neck Surgery, University Hospitals Case Medical Center, Cleveland, OH (United States); Buatti, John M. [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States); Machtay, Mitchell [Department of Radiation Oncology, University Hospitals Case Medical Center, Cleveland, OH (United States)

    2012-06-01

    Purpose: To determine the pattern and risk factors for distant metastases in head-and-neck squamous cell carcinoma (HNSCC) after curative treatment with intensity-modulated radiotherapy (IMRT). Methods and Materials: This was a retrospective study of 284 HNSCC patients treated in a single institution with IMRT. Sites included were oropharynx (125), oral cavity (70), larynx (55), hypopharynx (17), and unknown primary (17). American Joint Committee on Cancer stage distribution includes I (3), II (19), III (42), and IV (203). There were 224 males and 60 females with a median age of 57. One hundred eighty-six patients were treated with definitive IMRT and 98 postoperative IMRT. One hundred forty-nine patients also received concurrent cisplatin-based chemotherapy. Results: The median follow-up for all patients was 22.8 months (range, 0.07-77.3 months) and 29.5 months (4.23-77.3 months) for living patients. The 3-year local recurrence-free survival, regional recurrence-free survival, locoregional recurrence-free survival, distant metastasis-free survival, and overall survival were 94.6%, 96.4%, 92.5%, 84.1%, and 68.95%, respectively. There were 45 patients with distant metastasis. In multivariate analysis, distant metastasis was strongly associated with N stage (p = 0.046), T stage (p < 0.0001), and pretreatment maximum standardized uptake value of the lymph node (p = 0.006), but not associated with age, gender, disease sites, pretreatment standardized uptake value of the primary tumor, or locoregional control. The freedom from distant metastasis at 3 years was 98.1% for no factors, 88.6% for one factor, 68.3% for two factors, and 41.7% for three factors (p < 0.0001 by log-rank test). Conclusion: With advanced radiation techniques and concurrent chemotherapy, the failure pattern has changed with more patients failing distantly. The majority of patients with distant metastases had no local or regional failures, indicating that these patients might have microscopic distant

  5. Simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) in nasopharyngeal cancer

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    Studer, Gabriela [Dept. of Radiation Oncology, Univ. Hospital, Zurich (Switzerland); Peponi, Evangelia; Glanzmann, Christoph; Kunz, Guntram; Renner, Christoph; Tomuschat, Katja

    2010-03-15

    Purpose: To assess the efficacy and safety of using simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) to treat nasopharyngeal cancer (NPC) in a Caucasian cohort. Outcome was analyzed with respect to dose-volume histogram (DVH) values. Patients and Methods: Between 03/2002 and 01/2008, 39 NPC patients underwent SIB-IMRT (37 Caucasians; 31 males; mean age 53 years [16-78 years]). 41% presented with WHO (World Health Organization) type 1 unfavorable histology, 85% with stage III/IV disease. 19 patients had total gross tumor volume (GTV) 16-70 cm{sup 3} (mean 36 cm{sup 3}), while 16 had GTV > 70 cm{sup 3} (73-217 cm{sup 3}; mean 115 cm{sup 3}). All patients with stage II-IV disease received concomitant cisplatin. The prescribed SIB dose delivered to the planning target volume (PTV) was 70 Gy (2.00 Gy/fraction) in 17, 69.6 Gy (2.11 Gy/fraction) in 19, and 66 Gy (2.20 Gy/fraction) in three patients. Results: 3-year local relapse-free, nodal relapse-free, distant metastases-free, disease-free rates and overall survival were 86%, 89%, 85%, 72%, and 85% (median follow-up 30 months [8-71 months]). Histology was a significant prognostic factor concerning overall survival, with worst prognosis in WHO type 1 compared to type 2/3 (75% vs. 93%; p = 0.03). There was a trend in favor of WHO type 2/3 regarding local control (74% vs. 94%; p = 0.052). The PTV DVHs showed a slight left shift compared to reported series. Three patients developed grade 3 late effects (xerostomia [n=2], dysphagia [n=1], hearing loss [n=1]). Conclusion: In comparison with predominantly Asian NPC IMRT series in the literature, chemo-IMRT in the own Caucasian cohort, characterized by less radioresponsive WHO type 1, was equally effective. Treatment tolerance was excellent. (orig.)

  6. Salivary Gland Tumors Treated With Adjuvant Intensity-Modulated Radiotherapy With or Without Concurrent Chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfeld, Jonathan D., E-mail: jdschoenfeld@partners.org [Department of Radiation Oncology, Harvard Radiation Oncology Program, Boston, MA (United States); Sher, David J. [Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women' s Hospital, Boston, MA (United States); Norris, Charles M. [Department of Surgery, Division of Otolaryngology, Brigham and Women' s Hospital, Boston, MA (United States); Haddad, Robert I.; Posner, Marshall R. [Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA (United States); Department of Medicine, Brigham and Women' s Hospital, Boston, MA (United States); Balboni, Tracy A.; Tishler, Roy B. [Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women' s Hospital, Boston, MA (United States)

    2012-01-01

    Purpose: To analyze the recent single-institution experience of patients with salivary gland tumors who had undergone adjuvant intensity-modulated radiotherapy (IMRT), with or without concurrent chemotherapy. Patients and Methods: We performed a retrospective analysis of 35 salivary gland carcinoma patients treated primarily at the Dana-Farber Cancer Institute between 2005 and 2010 with surgery and adjuvant IMRT. The primary endpoints were local control, progression-free survival, and overall survival. The secondary endpoints were acute and chronic toxicity. The median follow-up was 2.3 years (interquartile range, 1.2-2.8) among the surviving patients. Results: The histologic types included adenoid cystic carcinoma in 15 (43%), mucoepidermoid carcinoma in 6 (17%), adenocarcinoma in 3 (9%), acinic cell carcinoma in 3 (9%), and other in 8 (23%). The primary sites were the parotid gland in 17 (49%), submandibular glands in 6 (17%), tongue in 4 (11%), palate in 4 (11%), and other in 4 (11%). The median radiation dose was 66 Gy, and 22 patients (63%) received CRT. The most common chemotherapy regimen was carboplatin and paclitaxel (n = 14, 64%). A trend was seen for patients undergoing CRT to have more adverse prognostic factors, including Stage T3-T4 disease (CRT, n = 12, 55% vs. n = 4, 31%, p = .29), nodal positivity (CRT, n = 8, 36% vs. n = 1, 8%, p = .10), and positive margins (n = 13, 59% vs. n = 5, 38%, p = .30). One patient who had undergone CRT developed an in-field recurrence, resulting in an overall actuarial 3-year local control rate of 92%. Five patients (14%) developed distant metastases (1 who had undergone IMRT only and 4 who had undergone CRT). Acute Grade 3 mucositis, esophagitis, and dermatitis occurred in 8%, 8%, and 8% (1 each) of IMRT patients and in 18%, 5%, and 14% (4, 1, and 3 patients) of the CRT group, respectively. No acute Grade 4 toxicity occurred. The most common late toxicity was Grade 1 xerostomia (n = 8, 23%). Conclusions: Treatment of

  7. A fixed-jaw method to protect critical organs during intensity-modulated radiotherapy

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    Chen, Jiayun; Chen, Xinyuan [Department of Radiation Oncology, Cancer Hospital (Institute), Chinese Academy of Medical Sciences, Beijing (China); Huang, Manni, E-mail: dai_jianrong@163.com [Department of Gynecologic Oncology, Cancer Hospital (Institute), Chinese Academy of Medical Sciences, Beijing (China); Dai, Jianrong, E-mail: huangmanni@csco.org.cn [Department of Radiation Oncology, Cancer Hospital (Institute), Chinese Academy of Medical Sciences, Beijing (China)

    2014-01-01

    Intensity-modulated radiotherapy (IMRT) plays an important role in cancer radiotherapy. For some patients being treated with IMRT, the extremely low tolerances of critical organs (such as lens, ovaries, and testicles) cannot be met during treatment planning. The aim of this article is to introduce a new planning method to overcome that problem. In current planning practice, jaw positions are automatically set to cover all target volumes by the planning system (e.g., Pinnacle{sup 3} system). Because of such settings, critical organs may be fully blocked by the multileaf collimator (MLC), but they still sit in the field that is shaped by collimator jaws. These critical organs receive doses from the transmission and leakage of MLC leaves. We manually fixed jaw positions to block them to further reduce such doses. This method has been used for different treatment sites in our clinic, and it was thoroughly evaluated in patients with radical hysterectomy plus ovarian transposition after surgery. For each patient, 2 treatment plans were designed with the same optimization parameters: the original plan with automatically chosen jaw positions (called O-plan) and the plan with fixed-jaw positions (named F-plan). In the F-plan, the jaws were manually fixed to block the ovaries. For target coverage, the mean conformity index (CI) of the F-plan (1.28 ± 0.02) was remarkably lower than that of the O-plan (1.53 ± 0.09) (p < 0.05). The F-plan and the O-plan performed similarly in target dose homogeneity. Meanwhile, for the critical organ sparing, the mean dose of both ovaries were much lower in the F-plan than that in the O-plan (p < 0.05). The V{sub 20}, V{sub 30}, and V{sub 40} of bladder were also lower in the F-plan (93.57 ± 1.98, 73.99 ± 5.76, and 42.33 ± 3.7, respectively) than those in the O-plan (97.98 ± 1.11, 85.07 ± 4.04, and 49.71 ± 3.63, respectively) (p < 0.05). The maximum dose to the spinal cord planning organ at risk (OAR) volume (PRV) in the O-plan (3940

  8. SU-E-T-449: Hippocampal Sparing Radiotherapy Using Intensity Modulated Radiotherapy and Volumetric Modulated Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S [Korea University, Seoul (Korea, Republic of); Kyung Hee University Hospital at Gangdong, Gangdong-gu (Korea, Republic of); Kim, D; Chung, W [Kyung Hee University Hospital at Gangdong, Gangdong-gu (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: The hippocampus sparing during the cranial irradiation has become interesting because it may mitigate radiation-induced neurocognitive toxicity. Herein we report our preliminary study for sparing the hippocampus with and without tilling condition for patient with brain metastases. Methods: Ten patients previously treated with whole brain were reviewed. Five patients tilted the head to around 30 degrees and others were treated without tilting. Treatment plans of linear accelerator (Linac)-based volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) were generated for prescription dose of 30 Gy in 15 fractions. Hippocampal avoidance regions were created with 5-mm volumetric expansion around the hippocampus. Whole brain, hippocampus and hippocampal avoidance volume were 1372cm3, 6cm3 and 30cm3 and hippocampal avoidance volume was 2.2% of the whole brain planned target volume in average. Organs at risk (OARs) are hippocampus, eyes, lens, and cochleae. Coverage index (CVI), conformity index (CI), homogeneity index (HI) and mean dose to OARs were used to compare dose characteristic of tilted and non-tilted cases. Results: In IMRT, when CI, CVI and HI of whole brain were 0.88, 0.09 and 0.98 in both tilted and non-tilted cases, absorbed dose of hippocampal avoidance volume in tilted cases were 10% lower than non-tilted cases. Doses in other OARs such as eyes, lens, and cochleae were also decreased about 20% when tilting the head. When CI, HI and CVI in VMAT were 0.9, 0.08 and 0.99, the dose-decreased ratio of OARs in both with and without tilting cases were almost the same with IMRT. But absolute dose of hippocampal avoidance volume in VMAT was 30% lower than IMRT. Conclusion: This study confirms that dose to hippocampus decreases if patients tilt the head. When treating the whole brain with head tilted, patients can acquire the same successful treatment Result and also preserve their valuable memory.

  9. Intensity modulated radiotherapy in early stage Hodgkin lymphoma patients: Is it better than three dimensional conformal radiotherapy?

    Directory of Open Access Journals (Sweden)

    De Sanctis Vitaliana

    2012-08-01

    Full Text Available Abstract Background Cure rate of early Hodgkin Lymphoma are high and avoidance of late toxicities is of paramount importance. This comparative study aims to assess the normal tissue sparing capability of intensity-modulated radiation therapy (IMRT versus standard three-dimensional conformal radiotherapy (3D-CRT in terms of dose-volume parameters and normal tissue complication probability (NTCP for different organs at risk in supradiaphragmatic Hodgkin Lymphoma (HL patients. Methods Ten HL patients were actually treated with 3D-CRT and all treatments were then re-planned with IMRT. Dose-volume parameters for thyroid, oesophagus, heart, coronary arteries, lung, spinal cord and breast were evaluated. Dose-volume histograms generated by TPS were analyzed to predict the NTCP for the considered organs at risk, according to different endpoints. Results Regarding dose-volume parameters no statistically significant differences were recorded for heart and origin of coronary arteries. We recorded statistically significant lower V30 with IMRT for oesophagus (6.42 vs 0.33, p = 0.02 and lungs (4.7 vs 0.1 p = 0.014 for the left lung and 2.59 vs 0.1 p = 0.017 for the right lung and lower V20 for spinal cord (17.8 vs 7.2 p = 0.02. Moreover the maximum dose to the spinal cord was lower with IMRT (30.2 vs 19.9, p Conclusions In HL male patients IMRT seems feasible and accurate while for women HL patients IMRT should be used with caution.

  10. Quality of life after intensity-modulated radiotherapy for prostate cancer with a hydrogel spacer. Matched-pair analysis

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    Pinkawa, M.; Piroth, M.D.; Holy, R.; Escobar-Corral, N.; Caffaro, M.; Djukic, V.; Klotz, J.; Eble, M.J. [RWTH Aachen Univ. (Germany). Dept. of Radiation Oncology

    2012-10-15

    Background: Hydrogel spacer is an innovative method to protect the rectal wall during prostate cancer radiotherapy. Clinical effects are not well known. Methods: Patients have been surveyed before, at the last day, and 2-3 months after radiotherapy using a validated questionnaire (Expanded Prostate Cancer Index Composite). Median dose to the prostate in the spacer subgroup (SP) was 78 Gy in 2 Gy fractions. The results were independently compared with two matched-pair subgroups (treated conventionally without spacer): 3D conformal 70.2 Gy in 1.8 Gy fractions (3DCRT) and intensity-modulated radiotherapy (IMRT) 76 Gy in 2 Gy fractions. There were 28 patients in each of the three groups. Results: Baseline mean bowel bother scores were 96 points in all subgroups. Similar mean changes (SP 16, 3DCRT 14, IMRT 17 points) were observed at the end of radiotherapy. The smallest difference resulted in the spacer subgroup 2-3 months after radiotherapy (SP 2, 3DCRT 8, IMRT 6 points). Bowel bother scores were only significantly different in comparison to baseline levels in the spacer subgroup. The percentage of patients reporting moderate/big bother with specific symptoms did not increase for any item (urgency, frequency, diarrhoea, incontinence, bloody stools, pain). Conclusion: Moderate bowel quality-of-life changes can be expected during radiotherapy irrespective of spacer application or total dose. Advantages with a spacer can be expected a few weeks after treatment. (orig.)

  11. The normal tissue sparing obtained with simultaneous treatment of pelvic lymph nodes and bladder using intensity-modulated radiotherapy

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    Soendergaard, Jimmi; Hoeyer, Morten; Wright, Pauliina; Grau, Cai; Muren, Ludvig Paul (Dept. of Oncology, Aarhus Univ. Hospital, Aarhus (Denmark)); Petersen, Joergen B. (Dept. of Medical Physics, Aarhus Univ. Hospital, Aarhus (Denmark))

    2009-02-15

    We have implemented an intensity-modulated radiotherapy (IMRT) protocol for simultaneous irradiation of bladder and lymph nodes. In this report, doses to normal tissue from IMRT and our previous conformal sequential boost technique are compared. Material and methods. Sixteen patients with urinary bladder cancer were treated using a six-field dynamic IMRT beam arrangement delivering 60 Gy to the bladder and 48 Gy to the pelvic lymph nodes. Dose-volume histogram (DVH) parameters for relevant normal tissues (bowel, bowel cavity, rectum and femoral heads) for the IMRT plans were compared with corresponding DVHs from our previous conformal sequential boost technique. Calculations of the generalized Equivalent Uniform Dose (gEUD) were performed for the bowel, with a reference volume of 200 cm3 and a volume effect parameter k = 4, as well as for the rectum, using k = 12. Acute gastrointestinal (GI) and genitourinary (GU) RTOG toxicity was recorded. Results. Statistical significant normal tissue sparing was obtained by IMRT. For the bowel, a significant reduction was obtained at all dose levels between 20 and 50 Gy (p < 0.05), e.g. from 180 to 121 cm3 at 50 Gy, while the gEUD was reduced from 58 to 53 Gy (p < 0.05). Similar patterns were seen for the bowel cavity. For the rectum, IMRT reduced the maximum dose as well as the volumes receiving more than 50 and 60 Gy (p < 0.05), e.g. from 72 to 48 cm3 at 50 Gy. The rectum gEUD was reduced from 55 to 53 Gy (p < 0.05). For the femoral heads, IMRT reduced the maximum dose as well as the volumes above all dose levels. The rate of acute peak Grade 2 GI RTOG complications was 38% after IMRT. Conclusion. IMRT to the urinary bladder and elective lymph nodes result in considerable normal tissue sparing compared to conformal sequential boost technique. This has paved the way for further studies combining IMRT with image-guided radiotherapy (IGRT) in bladder cancer.

  12. Dosimetric Verification of Intensity Modulated Radiotherapy with an Electronic Portal Imaging Device

    NARCIS (Netherlands)

    S.C. Vieira

    2005-01-01

    textabstractKanker is de ongecontroleerde proliferatie en verspreiding van cellen en kan zich manisfesteren in bijna het hele lichaam. Meeste kankers worden behandeld met chirurgie, bestraling (radiotherapie), en/of met medicijnen (chemotherapie). De stralenbron voor radiotherapie kan zich buiten

  13. Dosimetric study comparing intensity modulated and conformal pelvic radiotherapy boost plans in locally advanced cancer cervix in NCI-Cairo

    Institute of Scientific and Technical Information of China (English)

    Mohamed Mahmoud; Hesham A. EL-Hossiny; Nashaat A. Diab; Mahmoud Shosha

    2013-01-01

    Objective: This study was to compare 5 field conformal technique to the intensity modulated radiotherapy (IMRT) 8 fields technique in boosting locally advanced cancer cervix cases after external beam radiotherapy with respect to target volume coverage and dose to normal tissues. Methods: We conducted a single institutional comparative dosimetric analysis of 10 patients with cancer cervix who was presented to radiotherapy department in National Cancer Institute, Cairo in period between June 2012 to September 2012 and received a CRT boost in the place of planned brachytherapy after large field pelvic radiotherapy (PRT) with concurrent chemotherapy were retrospectively identified. All tumors were situated in the low central pelvis. Two plans were done for every patient; one using the 8 fields IMRT and the second one using 5 fields' 3DCRT the two techniques were then compared using dose volume histogram (DVH) analysis for the PTV, bladder, rectum and both femoral heads. Results: Comparing different DVHs, it was found that the planning target volume (PTV) was adequately covered in both plans while it was demonstrates that the 8 fields IMRT technique carried less doses reaching OARs (rectum, bladder, both femoral heads). Conclusion: From the present study, it is concluded that IMRT technique spared more efficiently OARs than CRT technique but both techniques covered the PTV adequately so whenever possible IMRT technique should be used.

  14. Simultaneous Integrated Boost Using Intensity-Modulated Radiotherapy Compared With Conventional Radiotherapy in Patients Treated With Concurrent Carboplatin and 5-Fluorouracil for Locally Advanced Oropharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Clavel, Sebastien, E-mail: sebastien.clavel@umontreal.ca [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Nguyen, David H.A.; Fortin, Bernard [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada); Despres, Philippe [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Khaouam, Nader [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada); Donath, David [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Soulieres, Denis [Department of Medical Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Guertin, Louis [Department of Head and Neck Surgery, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Nguyen-Tan, Phuc Felix [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada)

    2012-02-01

    Purpose: To compare, in a retrospective study, the toxicity and efficacy of simultaneous integrated boost using intensity-modulated radiotherapy (IMRT) vs. conventional radiotherapy (CRT) in patients treated with concomitant carboplatin and 5-fluorouracil for locally advanced oropharyngeal cancer. Methods and Materials: Between January 2000 and December 2007, 249 patients were treated with definitive chemoradiation. One hundred patients had 70 Gy in 33 fractions using IMRT, and 149 received CRT at 70 Gy in 35 fractions. Overall survival, disease-free survival, and locoregional control were estimated using the Kaplan-Meier method. Results: Median follow-up was 42 months. Three-year actuarial rates for locoregional control, disease-free survival, and overall survival were 95.1% vs. 84.4% (p = 0.005), 85.3% vs. 69.3% (p = 0.001), and 92.1% vs. 75.2% (p < 0.001) for IMRT and CRT, respectively. The benefit of the radiotherapy regimen on outcomes was also observed with a Cox multivariate analysis. Intensity-modulated radiotherapy was associated with less acute dermatitis and less xerostomia at 6, 12, 24, and 36 months. Conclusions: This study suggests that simultaneous integrated boost using IMRT is associated with favorable locoregional control and survival rates with less xerostomia and acute dermatitis than CRT when both are given concurrently with chemotherapy.

  15. A prospective comparison of acute intestinal toxicity following whole pelvic versus small field intensity-modulated radiotherapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Kim YJ

    2016-03-01

    Full Text Available Yeon Joo Kim, Jin-hong Park, In-Ha Yun, Young Seok KimDepartment of Radiation Oncology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of KoreaPurpose: To compare the acute intestinal toxicity of whole pelvic (WP and small field (SF intensity-modulated radiotherapy (IMRT for prostate cancer using dosimetric and metabolic parameters as well as clinical findings.Methods: Patients who received IMRT in either a definitive or postoperative setting were prospectively enrolled. Target volume and organs at risk including intestinal cavity (IC were delineated in every patient by a single physician. The IC volume that received a 10–50 Gy dose at 5-Gy intervals (V10–V50 and the percentage of irradiated volume as a fraction of total IC volume were calculated. Plasma citrulline levels, as an objective biological marker, were checked at three time points: baseline and after exposure to 30 Gy and 60 Gy.Results: Of the 41 patients, only six experienced grade 1 acute intestinal toxicity. Although all dose–volume parameters were significantly worse following WP than SF IMRT, there was no statistically significant relationship between these dosimetric parameters and clinical symptoms. Plasma citrulline levels did not show a serial decrease by radiotherapy volume difference (WP versus SF and were not relevant to the irradiated doses.Conclusion: Given that WP had comparable acute intestinal toxicities to those associated with SF, WP IMRT appears to be a feasible approach for the treatment of prostate cancer despite dosimetric disadvantages.Keywords: prostate cancer, intensity-modulated radiotherapy, intestinal toxicity, citrulline

  16. Intensity-Modulated and Image-Guided Radiotherapy in Patients with Locally Advanced Inoperable Pancreatic Cancer after Preradiation Chemotherapy

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    M. Sinn

    2014-01-01

    Full Text Available Background. Radiotherapy (RT in patients with pancreatic cancer is still a controversial subject and its benefit in inoperable stages of locally advanced pancreatic cancer (LAPC, even after induction chemotherapy, remains unclear. Modern radiation techniques such as image-guided radiotherapy (IGRT and intensity-modulated radiotherapy (IMRT may improve effectiveness and reduce radiotherapy-related toxicities. Methods. Patients with LAPC who underwent radiotherapy after chemotherapy between 09/2004 and 05/2013 were retrospectively analyzed with regard to preradiation chemotherapy (PRCT, modalities of radiotherapy, and toxicities. Progression-free (PFS and overall survival (OS were estimated by Kaplan-Meier curves. Results. 15 (68% women and 7 men (median age 64 years; range 40–77 were identified. Median duration of PRCT was 11.1 months (range 4.3–33.0. Six patients (27% underwent conventional RT and 16 patients (73% advanced IMRT and IGRT; median dosage was 50.4 (range 9–54 Gray. No grade III or IV toxicities occurred. Median PFS (estimated from the beginning of RT was 5.8 months, 2.6 months in the conventional RT group (conv-RT, and 7.1 months in the IMRT/IGRT group (P=0.029; median OS was 11.0 months, 4.2 months (conv-RT, and 14.0 months (IMRT/IGRT; P=0.141. Median RT-specific PFS for patients with prolonged PRCT > 9 months was 8.5 months compared to 5.6 months for PRCT 9 months group, with 19.0 months compared to 8.5 months in the PRCT  <  9 months group (P=0.049. Conclusions. IGRT and IMRT after PRCT are feasible and effective options for patients with LAPC after prolonged preradiation chemotherapy.

  17. Comparison of heart and coronary artery doses associated with intensity-modulated radiotherapy versus three-dimensional conformal radiotherapy for distal esophageal cancer.

    Science.gov (United States)

    Kole, Thomas P; Aghayere, Osarhieme; Kwah, Jason; Yorke, Ellen D; Goodman, Karyn A

    2012-08-01

    To compare heart and coronary artery radiation exposure using intensity-modulated radiotherapy (IMRT) vs. four-field three-dimensional conformal radiotherapy (3D-CRT) treatment plans for patients with distal esophageal cancer undergoing chemoradiation. Nineteen patients with distal esophageal cancers treated with IMRT from March 2007 to May 2008 were identified. All patients were treated to 50.4 Gy with five-field IMRT plans. Theoretical 3D-CRT plans with four-field beam arrangements were generated. Dose-volume histograms of the planning target volume, heart, right coronary artery, left coronary artery, and other critical normal tissues were compared between the IMRT and 3D-CRT plans, and selected parameters were statistically evaluated using the Wilcoxon rank-sum test. Intensity-modulated radiotherapy treatment planning showed significant reduction (p coronary artery (average mean dose, 23.8 Gy vs. 35.5 Gy), whereas the left coronary artery showed no significant improvement (mean dose, 11.2 Gy vs. 9.2 Gy), p = 0.11. There was no significant difference in percentage of total lung volume receiving at least 10, 15, or 20 Gy or in the mean lung dose between the planning methods. There were also no significant differences observed for the kidneys, liver, stomach, or spinal cord. Intensity-modulated radiotherapy achieved a significant improvement in target conformity as measured by the conformality index (ratio of total volume receiving 95% of prescription dose to planning target volume receiving 95% of prescription dose), with the mean conformality index reduced from 1.56 to 1.30 using IMRT. Treatment of patients with distal esophageal cancer using IMRT significantly decreases the exposure of the heart and right coronary artery when compared with 3D-CRT. Long-term studies are necessary to determine how this will impact on development of coronary artery disease and other cardiac complications. Copyright © 2012 Elsevier Inc. All rights reserved.

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

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    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. Dosimetric comparison of postoperative whole pelvic radiotherapy for endometrial cancer using three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and helical tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ruijie Yang; Weijuan Jiang; Junjie Wang [Dept. of Radiation Oncology, Cancer Center, Peking Univ. Third Hospital, Beijing (China)], E-mail: ruijyang@yahoo.com; Shouping Xu; Chuanbin Xie [Dept. of Radiation Oncology, General Hospital of the People' s Liberation ArmyBeijing (China)

    2010-02-15

    Background. The use of Intensity-modulated radiotherapy (IMRT) and Helical tomotherapy (HT) is increasing in gynecological cancer patients. No published studies have performed a dosimetric evaluation of whole pelvic radiotherapy (WPRT) using HT for postoperative endometrial cancer. The purpose of this study was to perform a direct dosimetric comparison of three-dimensional conformal radiotherapy (3D-CRT), IMRT and HT plans for WPRT in postoperative endometrial cancer patients, and to evaluate the integral dose to organs at risk (OARs) and normal tissue. Material and methods. We selected ten patients with endometrial cancer undergoing postoperative WPRT. Plans for 3D-CRT, IMRT and HT were developed for each patient. All plans were normalized to deliver 50 Gy to 95% of the PTV. The dosimetry and integral dose to OARs and normal tissue were compared. The significance of differences was tested using a paired two-tailed Student t-test. Results. IMRT were superior to 3D-CRT in dose conformity (conformity index: 0.87 vs. 0.61, p 0.00) and integral dose to OARs and normal tissue, although a greater volume of normal tissue receiving dose below 10 Gy was observed. The results were similar in HT except that the integral dose to normal tissue increased slightly. Compared directly with IMRT, HT showed better dose homogeneity and lower integral dose to rectum and bladder, but the integral dose to pelvic bones and normal tissue slightly increased. Conclusions. In postoperative WPRT of endometrial cancer, IMRT and HT result in better conformity and lower integral dose to OARs compared with 3D-CRT. The integral dose to normal tissue did not increase significantly in IMRT, although a greater volume of normal tissue is irradiated to the dose below 10 Gy. HT further improves the dose homogeneity and integral dose to rectum and bladder, at the expense of a slightly higher integral dose to pelvic bones and normal tissue.

  20. Dosimetric comparison of postoperative whole pelvic radiotherapy for endometrial cancer using three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and helical tomotherapy.

    Science.gov (United States)

    Yang, Ruijie; Xu, Shouping; Jiang, Weijuan; Wang, Junjie; Xie, Chuanbin

    2010-01-01

    The use of Intensity-modulated radiotherapy (IMRT) and Helical tomotherapy (HT) is increasing in gynecological cancer patients. No published studies have performed a dosimetric evaluation of whole pelvic radiotherapy (WPRT) using HT for postoperative endometrial cancer. The purpose of this study was to perform a direct dosimetric comparison of three-dimensional conformal radiotherapy (3D-CRT), IMRT and HT plans for WPRT in postoperative endometrial cancer patients, and to evaluate the integral dose to organs at risk (OARs) and normal tissue. We selected ten patients with endometrial cancer undergoing postoperative WPRT. Plans for 3D-CRT, IMRT and HT were developed for each patient. All plans were normalized to deliver 50 Gy to 95% of the PTV. The dosimetry and integral dose to OARs and normal tissue were compared. The significance of differences was tested using a paired two-tailed Student t-test. IMRT were superior to 3D-CRT in dose conformity (conformity index: 0.87 vs. 0.61, p = 0.00) and integral dose to OARs and normal tissue, although a greater volume of normal tissue receiving dose below 10 Gy was observed. The results were similar in HT except that the integral dose to normal tissue increased slightly. Compared directly with IMRT, HT showed better dose homogeneity and lower integral dose to rectum and bladder, but the integral dose to pelvic bones and normal tissue slightly increased. In postoperative WPRT of endometrial cancer, IMRT and HT result in better conformity and lower integral dose to OARs compared with 3D-CRT. The integral dose to normal tissue did not increase significantly in IMRT, although a greater volume of normal tissue is irradiated to the dose below 10 Gy. HT further improves the dose homogeneity and integral dose to rectum and bladder, at the expense of a slightly higher integral dose to pelvic bones and normal tissue.

  1. Dosimetric comparison of postoperative whole pelvic radiotherapy for endometrial cancer using three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and helical tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ruijie Yang; Weijuan Jiang; Junjie Wang (Dept. of Radiation Oncology, Cancer Center, Peking Univ. Third Hospital, Beijing (China)), E-mail: ruijyang@yahoo.com; Shouping Xu; Chuanbin Xie (Dept. of Radiation Oncology, General Hospital of the People' s Liberation ArmyBeijing (China))

    2010-02-15

    Background. The use of Intensity-modulated radiotherapy (IMRT) and Helical tomotherapy (HT) is increasing in gynecological cancer patients. No published studies have performed a dosimetric evaluation of whole pelvic radiotherapy (WPRT) using HT for postoperative endometrial cancer. The purpose of this study was to perform a direct dosimetric comparison of three-dimensional conformal radiotherapy (3D-CRT), IMRT and HT plans for WPRT in postoperative endometrial cancer patients, and to evaluate the integral dose to organs at risk (OARs) and normal tissue. Material and methods. We selected ten patients with endometrial cancer undergoing postoperative WPRT. Plans for 3D-CRT, IMRT and HT were developed for each patient. All plans were normalized to deliver 50 Gy to 95% of the PTV. The dosimetry and integral dose to OARs and normal tissue were compared. The significance of differences was tested using a paired two-tailed Student t-test. Results. IMRT were superior to 3D-CRT in dose conformity (conformity index: 0.87 vs. 0.61, p 0.00) and integral dose to OARs and normal tissue, although a greater volume of normal tissue receiving dose below 10 Gy was observed. The results were similar in HT except that the integral dose to normal tissue increased slightly. Compared directly with IMRT, HT showed better dose homogeneity and lower integral dose to rectum and bladder, but the integral dose to pelvic bones and normal tissue slightly increased. Conclusions. In postoperative WPRT of endometrial cancer, IMRT and HT result in better conformity and lower integral dose to OARs compared with 3D-CRT. The integral dose to normal tissue did not increase significantly in IMRT, although a greater volume of normal tissue is irradiated to the dose below 10 Gy. HT further improves the dose homogeneity and integral dose to rectum and bladder, at the expense of a slightly higher integral dose to pelvic bones and normal tissue

  2. Dose reduction to normal tissues as compared to the gross tumor by using intensity modulated radiotherapy in thoracic malignancies

    Directory of Open Access Journals (Sweden)

    Bhalla NK

    2006-08-01

    Full Text Available Abstract Background and purpose Intensity modulated radiotherapy (IMRT is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities. The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for thoracic malignancies. Materials and methods During the period January 2002 to March 2004, 12 patients of various sites of malignancies in the thoracic region were treated using physical intensity modulator based IMRT. Plans of these patients treated with IMRT were analyzed using dose volume histograms. Results An average dose reduction of the mean values by 73% to the heart, 69% to the right lung and 74% to the left lung, with respect to the GTV could be achieved with IMRT. The 2 year disease free survival was 59% and 2 year overall survival was 59%. The average number of IMRT fields used was 6. Conclusion IMRT with inverse planning enabled us to achieve desired dose distribution, due to its ability to provide sharp dose gradients at the junction of tumor and the adjacent critical organs.

  3. Spine radiosurgery for the local treatment of spine metastases: Intensity-modulated radiotherapy, image guidance, clinical aspects and future directions

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Fabio Ynoe de; Neves-Junior, Wellington Furtado Pimenta; Hanna, Samir Abdallah; Carvalho, Heloisa de Andrade [Hospital Sirio-Libanes, Sao Paulo, SP (Brazil). Departamento de Radioterapia; Taunk, Neil Kanth; Yamada, Yoshiya [Memorial Sloan Kettering Cancer Center, Department of Radiation Oncology, New York, NY (United States); Laufer, Ilya, E-mail: fymoraes@gmail.com [Memorial Sloan Kettering Cancer Center, Department of Neurosurgery, New York, NY (United States)

    2016-02-15

    Many cancer patients will develop spinal metastases. Local control is important for preventing neurologic compromise and to relieve pain. Stereotactic body radiotherapy or spinal radiosurgery is a new radiation therapy technique for spinal metastasis that can deliver a high dose of radiation to a tumor while minimizing the radiation delivered to healthy, neighboring tissues. This treatment is based on intensity-modulated radiotherapy, image guidance and rigid immobilization. Spinal radiosurgery is an increasingly utilized treatment method that improves local control and pain relief after delivering ablative doses of radiation. Here, we present a review highlighting the use of spinal radiosurgery for the treatment of metastatic tumors of the spine. The data used in the review were collected from both published studies and ongoing trials. We found that spinal radiosurgery is safe and provides excellent tumor control (up to 94% local control) and pain relief (up to 96%), independent of histology. Extensive data regarding clinical outcomes are available; however, this information has primarily been generated from retrospective and non randomized prospective series. Currently, two randomized trials are enrolling patients to study clinical applications of fractionation schedules spinal Radiosurgery. Additionally, a phase I clinical trial is being conducted to assess the safety of concurrent stereotactic body radiotherapy and ipilimumab for spinal metastases. Clinical trials to refine clinical indications and dose fractionation are ongoing. The concomitant use of targeted agents may produce better outcomes in the future. (author)

  4. Intensity Modulated Radiotherapy (IMRT in the postoperative treatment of an adenocarcinoma of the endometrium complicated by a pelvic kidney

    Directory of Open Access Journals (Sweden)

    Novaes Paulo ERS

    2006-11-01

    Full Text Available Abstract Background Pelvic Radiotherapy (RT as a postoperative treatment for endometrial cancer improves local regional control. Brachytherapy also improves vaginal control. Both treatments imply significant side effects that a fine RT technique can help avoiding. Intensity Modulated RT (IMRT enables the treatment of the target volume while protecting normal tissue. It therefore reduces the incidence and severity of side effects. Case We report on a 50 year-old patient with a serous-papiliferous adenocarcinoma of the uterus who was submitted to surgical treatment without lymph node sampling followed by Brachytherapy, and Chemotherapy. The patient had a pelvic kidney, and was therefore treated with IMRT. So far, the patient has been free from relapse and with normal kidney function. Conclusion IMRT is a valid technique to prevent the kidney from radiation damage.

  5. Treatment outcome of localized prostate cancer by 70 Gy hypofractionated intensity-modulated radiotherapy with a customized rectal balloon

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    Kim, Hyun Jung; Kim, Jun Won; Hong, Sung Joon; Rha, Koon Ho; Lee, Chang Geol; Yang, Seung Choul; Choi, Young Deuk; Suh, Chang Ok; Cho, Jae Ho [Yonsei Cancer Center, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-09-15

    We aimed to analyze the treatment outcome and long-term toxicity of 70 Gy hypofractionated intensity-modulated radiotherapy (IMRT) for localized prostate cancer using a customized rectal balloon. We reviewed medical records of 86 prostate cancer patients who received curative radiotherapy between January 2004 and December 2011 at our institution. Patients were designated as low (12.8%), intermediate (20.9%), or high risk (66.3%). Thirty patients received a total dose of 70 Gy in 28 fractions over 5 weeks via IMRT (the Hypo-IMRT group); 56 received 70.2 Gy in 39 fractions over 7 weeks via 3-dimensional conformal radiotherapy (the CF-3DRT group, which served as a reference for comparison). A customized rectal balloon was placed in Hypo-IMRT group throughout the entire radiotherapy course. Androgen deprivation therapy was administered to 47 patients (Hypo-IMRT group, 17; CF-3DRT group, 30). Late genitourinary (GU) and gastrointestinal (GI) toxicity were evaluated according to the Radiation Therapy Oncology Group criteria. The median follow-up period was 74.4 months (range, 18.8 to 125.9 months). The 5-year actuarial biochemical relapse-free survival rates for low-, intermediate-, and high-risk patients were 100%, 100%, and 88.5%, respectively, for the Hypo-IMRT group and 80%, 77.8%, and 63.6%, respectively, for the CF-3DRT group (p < 0.046). No patient presented with acute or late GU toxicity > or =grade 3. Late grade 3 GI toxicity occurred in 2 patients (3.6%) in the CF-3DRT group and 1 patient (3.3%) in the Hypo-IMRT group. Hypo-IMRT with a customized rectal balloon resulted in excellent biochemical control rates with minimal toxicity in localized prostate cancer patients.

  6. Comparison of dose contribution to normal pelvic tissues among conventional, conformal and intensity-modulated radiotherapy techniques in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yungan Tao; Lefkopoulos, Dimitri; Ibrahima, Diallo; Bridier, Andre; Polizzi, Maria del Pilar; Wibault, Pierre; Crevoisier, Renaud de; Arriagada, Rodrigo; Bourhis, Jean (Dept. of Radiotherapy, Institut Gustave-Roussy, Villejuif (France))

    2008-03-15

    High-energy external radiotherapy has become one of the most common treatment in localized prostate cancer. We compared the difference of dose distribution, mainly at the 5-30 Gy dose level, in the irradiated pelvic volume among three modalities of radiotherapy for patients with prostate cancer: conventional, conformal and intensity-modulated radiotherapy (IMRT). We selected six patients with prostate cancer treated by conformal radiotherapy at the doses of 46 Gy to PTVN (prostate and seminal vesicles), and 70 Gy to PTV-T (prostate). The conventional technique: an 8-field arrangement was used; the conformal technique 4 fields with a boost through 6 fields. For IMRT, a five-beam arrangement was used. Dose-volume histograms (DVH) were analyzed and compared among the three techniques. The IMRT technique significantly increased the pelvic volume covered by the isodose surfaces below 15 Gy as compared with the conventional and conformal techniques. The mean absolute increase for the pelvic volume included between 5-30 Gy for the IMRT technique, was about 2 900 ml as compared with the conventional technique. However, IMRT significantly reduced the irradiated volume of the rectum in the dose range of 5 to 40 Gy, also significantly reduced the irradiated volume of bladder and femoral heads, and obtained a similar or improved isodose distribution in the PTVs. In addition, the use of IMRT slightly increased the relative dose delivered to the body volume outside the pelvis, as estimated by the use of specific software. A long-term follow-up will be needed to evaluate potential late treatment complications related to the use of IMRT and the low or moderate irradiation dose level obtained in the pelvis and in the whole body

  7. Analysis of Factors Influencing the Development of Xerostomia during Intensity-Modulated Radiotherapy

    Science.gov (United States)

    Randall, Ken; Stevens, Jason; Yepes, Juan Fernando; Randall, Marcus E.; Kudrimoti, Mahesh; Feddock, Jonathan; Xi, Jing; Kryscio, Richard J.; Miller, Craig S.

    2013-01-01

    OBJECTIVES Factors influencing xerostomia during intensity-modulated radiation therapy (IMRT) were assessed. METHODS A 6-week study of 32 head and neck cancer (HNC) patients was performed. Subjects completed the Xerostomia Inventory (XI) and provided stimulated saliva (SS) at baseline, week two and at end of IMRT. Influence of SS flow rate (SSFR), calcium and mucin 5b (MUC5b) concentrations and radiation dose on xerostomia was determined. RESULTS HNC subjects experienced mean SSFR decline of 36% by visit two (N=27; p=0.012) and 57% by visit three (N=20; p=0.0004), Concentrations of calcium and MUC5b increased, but not significantly during IMRT (p>0.05). Xerostomia correlated most with decreasing salivary flow rate as determined by Spearman correlations (p<0.04) and linear mixed models (p<0.0001). CONCLUSIONS Although IMRT is sparing to the parotid glands, it has an early effect on SSFR and the constituents in saliva in a manner that is associated with the perception of xerostomia. PMID:23523462

  8. Correlation between intensity modulated radiotherapy and bone marrow suppression in breast cancer.

    Science.gov (United States)

    Wang, Q; Ye, T; Chen, H-L; Zhang, X-G; Zhang, L-Z

    2016-01-01

    To study the correlation factors of bone marrow suppression in breast cancer radiotherapy and find out the method to guide the target area, dose limitation for breast cancer to reduce the risk of bone marrow suppression. 72 cases of breast cancer patients were collected through retrospective, clinical control study. For patients with Grade 0-3, bone marrow suppression in the course of radiotherapy, the dose-volume parameters (V5, V10, V20, V30, V50, D20, D40, D60, D80, D100, Min, Max, Dmean) of the chest and rib of each patient were collected and analyzed from multiple points including tumor stage, age, lesion location, surgical approach, chemotherapy regimen and the number of cycles, bone dose-volume parameters. The relative parameters of the rib in the middle and severe bone marrow suppression group were significantly higher than those in the mild bone marrow depression group and the p values of V5, V10, V20, V30, Dmean, D40, D60, D80, D100 were less than 0.05. The difference of V50 in the two groups was statistically significant (p <0.05). For chemotherapy regimens containing doxorubicin, epirubicin, cyclophosphamide, the differences between bone marrow suppression group and non-bone marrow suppression were statistically significant (p =0.002). The dose-volume parameters of the rib radiation is one of the main factors causing the suppression of bone marrow in radiotherapy, and the volume of the 50Gy irradiation is also a contribution to the bone marrow. For patients accepted chemotherapy with doxorubicin, epirubicin, cyclophosphamide before radiotherapy, bone marrow suppression is more likely to occur during radiotherapy. After radical mastectomy or the volume of thoracic rib is increased because of the small breast, the occurrence of bone marrow suppression is increased. The effects of radiation on the bone marrow suppression were small, while its effect on the ribs was more evident, especially on the ribs V20 and Dmean and the difference was statically

  9. Locoregionally advanced nasopharyngeal carcinoma treated with intensity-modulated radiotherapy plus concurrent weekly cisplatin with or without neoadjuvant chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wee, Chan Woo; Keam, Bhum Suk; Heo, Dae Seog; Sung, Myung Whun; Won, Tae Bin; Wu, Hong Gyun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    The outcomes of locoregionally advanced nasopharyngeal carcinoma patients treated with concurrent chemoradiation (CCRT) using intensity-modulated radiotherapy (IMRT) with/without neoadjuvant chemotherapy (NCT) were evaluated. Eighty-three patients who underwent NCT followed by CCRT (49%) or CCRT with/without adjuvant chemotherapy (51%) were reviewed. To the gross tumor, 67.5 Gy was prescribed. Weekly cisplatin was used as concurrent chemotherapy. With a median follow-up of 49.4 months, the 5-year local control, regional control, distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival rates were 94.7%, 89.3%, 77.8%, 68.0%, and 81.8%, respectively. In multivariate analysis, the American Joint Committee on Cancer stage (p = 0.016) and N stage (p = 0.001) were negative factors for DMFS and DFS, respectively. Overall, NCT demonstrated no benefit and an increased risk of severe hematologic toxicity. However, compared to patients treated with CCRT alone, NCT showed potential of improving DMFS in stage IV patients. CCRT using IMRT resulted in excellent local control and survival outcome. Without evidence of survival benefit from phase III randomized trials, NCT should be carefully administered in locoregionally advanced nasopharyngeal carcinoma patients who are at high-risk of developing distant metastasis and radiotherapy-related mucositis. The results of ongoing trials are awaited.

  10. SU-E-T-17: A Comparison of Forward and Field in Field Intensity Modulation Radiotherapy Planning for Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Liu, T; Sun, T; Chen, J; Zhang, G [shandong tumor hospital, Jinan, Shandong (China)

    2015-06-15

    Purpose: To compare the dosimetric difference in forward intensity modulation radiotherapy(fIMRT) and field in field IMRT (FIF IMRT)planning for breast cancer. Methods: Ten patients received radiotherapy are selected.For each patient,two treatment plans(fIMRT and FIF IMRT) were designed with Varian Eclipse ver11.0 treatment planning system.Evaluate the dose parameters of targets, organs at risk (OAR), monitor units and treatment time, using dose-volume histogram (DVH). Results: There were no significant difference were found in conformal index (CI), homogeneity index (HI) of PTV,V5,V10,V20,V30,V40,V50 of heart, lung and monitor unit(MU)(P>0.05).The differences were significant in the treatment time(fIMRT=8.3min,FIF IMRT=2.5,p<0.05). Conclusion: FIF IMRT is equal to fIMRT in dosimetril evaluation. Due to much less delivery time,FIF IMRT is an efficient technique in treating patients by reduceing the uncomfortable influnce which could effect the treatment.

  11. A prospective comparison of acute intestinal toxicity following whole pelvic versus small field intensity-modulated radiotherapy for prostate cancer

    Science.gov (United States)

    Kim, Yeon Joo; Park, Jin-hong; Yun, In-Ha; Kim, Young Seok

    2016-01-01

    Purpose To compare the acute intestinal toxicity of whole pelvic (WP) and small field (SF) intensity-modulated radiotherapy (IMRT) for prostate cancer using dosimetric and metabolic parameters as well as clinical findings. Methods Patients who received IMRT in either a definitive or postoperative setting were prospectively enrolled. Target volume and organs at risk including intestinal cavity (IC) were delineated in every patient by a single physician. The IC volume that received a 10–50 Gy dose at 5-Gy intervals (V10–V50) and the percentage of irradiated volume as a fraction of total IC volume were calculated. Plasma citrulline levels, as an objective biological marker, were checked at three time points: baseline and after exposure to 30 Gy and 60 Gy. Results Of the 41 patients, only six experienced grade 1 acute intestinal toxicity. Although all dose–volume parameters were significantly worse following WP than SF IMRT, there was no statistically significant relationship between these dosimetric parameters and clinical symptoms. Plasma citrulline levels did not show a serial decrease by radiotherapy volume difference (WP versus SF) and were not relevant to the irradiated doses. Conclusion Given that WP had comparable acute intestinal toxicities to those associated with SF, WP IMRT appears to be a feasible approach for the treatment of prostate cancer despite dosimetric disadvantages. PMID:27022287

  12. Postoperative pelvic intensity-modulated radiotherapy in high risk endometrial cancer.

    Science.gov (United States)

    Shih, Karin K; Milgrom, Sarah A; Abu-Rustum, Nadeem R; Kollmeier, Marisa A; Gardner, Ginger J; Tew, William P; Barakat, Richard R; Alektiar, Kaled M

    2013-03-01

    According to national surveys, the use of intensity-modulated radiation therapy (IMRT) in gynecologic cancers is on the rise, yet there is still some reluctance to adopt adjuvant IMRT as standard practice. The purpose of this study is to report a single-institution experience using postoperative pelvic IMRT with or without chemotherapy in high-risk endometrial cancer. From 11/2004 to 12/2009, 46 patients underwent hysterectomy/bilateral salpingo-oophorectomy for stage I-III (22% stage I/II and 78% stage III) endometrial cancer. Median IMRT dose was 50.4Gy. Adjuvant chemotherapy was given to 30 (65%) patients. With a median follow-up of 52months, 4 patients recurred: 1 vaginal plus lung metastasis, 2 isolated para-aortic recurrences, and 1 lungs and liver metastasis. Five-year relapse rate was 9% (95% CI, 0-13.6%). Five-year disease-free survival (DFS) was 88% (95% CI, 77-98%) and overall survival (OS) was 97% (95% CI, 90-100%). There were 2 patients with non-hematological grade 3 toxicity: 1 (2%) acute and 1 (2%) chronic gastrointestinal toxicity. In patients treated with IMRT and chemotherapy (n=30), 5 had grade 3 leukopenia, 8 grade 2 anemia, and 2 grade 2 thrombocytopenia. Oncologic outcomes with postoperative IMRT were very good, with DFS and OS rates of >88% at median follow-up of 52months, despite a preponderance (78%) of stage III disease. Toxicity was minimal even in the setting of an aggressive trimodality (65% of patients) approach. Data from this study and emerging data from RTOG trial 0418 demonstrate the advantages of IMRT in high-risk endometrial cancer. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Multivariate analysis of factors predicting prostate dose in intensity-modulated radiotherapy.

    Science.gov (United States)

    Tomita, Tsuneyuki; Nakamura, Mitsuhiro; Hirose, Yoshinori; Kitsuda, Kenji; Notogawa, Takuya; Miki, Katsuhito; Nakamura, Kiyonao; Ishigaki, Takashi

    2014-01-01

    We conducted a multivariate analysis to determine relationships between prostate radiation dose and the state of surrounding organs, including organ volumes and the internal angle of the levator ani muscle (LAM), based on cone-beam computed tomography (CBCT) images after bone matching. We analyzed 270 CBCT data sets from 30 consecutive patients receiving intensity-modulated radiation therapy for prostate cancer. With patients in the supine position on a couch with the HipFix system, data for center of mass (COM) displacement of the prostate and the state of individual organs were acquired and compared between planning CT and CBCT scans. Dose distributions were then recalculated based on CBCT images. The relative effects of factors on the variance in COM, dose covering 95% of the prostate volume (D95%), and percentage of prostate volume covered by the 100% isodose line (V100%) were evaluated by a backward stepwise multiple regression analysis. COM displacement in the anterior-posterior direction (COMAP) correlated significantly with the rectum volume (δVr) and the internal LAM angle (δθ; R = 0.63). Weak correlations were seen for COM in the left-right (R = 0.18) and superior-inferior directions (R = 0.31). Strong correlations between COMAP and prostate D95% and V100% were observed (R ≥ 0.69). Additionally, the change ratios in δVr and δθ remained as predictors of prostate D95% and V100%. This study shows statistically that maintaining the same rectum volume and LAM state for both the planning CT simulation and treatment is important to ensure the correct prostate dose in the supine position with bone matching. Copyright © 2014 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  14. Clinical Dosimetric Comparison among Different Intensity-Modulated Radiotherapy Plans for Nasopharyngeal Carcinoma

    Directory of Open Access Journals (Sweden)

    Changjiang Sun

    2014-03-01

    Full Text Available Objective: To compare the dosimetric differences of different intensity-modulated radiation therapy (IMRT plans for nasopharyngeal carcinoma (NPC. Methods: 5-, 7- and 9-fields of IMRT plans in 16 NPC patients were respectively designed and synchronous dimention technology was applied to compare the dosimetric differences in target areas and involved organs. Results: The recovery rate in target area was 95% while the plan was evidently worse in 5-field than in 7- and 9-fields (P < 0.05. Whereas the maximum dosage (Dmax, mean dosage (Dmean and minimum dosage (Dmin were similar between 7- and 9-fields (P > 0.05, which were obviously lower in 5-field, and the differences were both significant (P < 0.05. In addition, the conformity and homogeneity indexes in target area had no significant difference between 7- and 9-fields, but were markedly better than in 5-field (P < 0.05. Indexes in each involved organs were the lowest in 5-field than in other fields (P < 0.05, but were similar between 7- and 9-fields (P > 0.05, which were all lower than tolerant dosage. As for BODY, there were significant differences in V10 - V20 between 5-field and other fields (P < 0.05, but were similar in V25 - V30 (P > 0.05. However, 7- and 9-fields were similar in V10 - V20 (P > 0.05. Conclusion: 7-field IMRT plan is the optimal one for NPC on both clinical dosimetric requirements and field-establishment principles.

  15. Dosimetric and geometric evaluation of the use of deformable image registration in adaptive intensity-modulated radiotherapy for head-and-neck cancer

    DEFF Research Database (Denmark)

    Eiland, R B; Maare, Christian; Sjöström, D

    2014-01-01

    The aim of this study was to carry out geometric and dosimetric evaluation of the usefulness of a deformable image registration algorithm utilized for adaptive head-and-neck intensity-modulated radiotherapy. Data consisted of seven patients, each with a planning CT (pCT), a rescanning CT (Re...

  16. Volumetric-modulated arc radiotherapy for pancreatic malignancies: Dosimetric comparison with sliding-window intensity-modulated radiotherapy and 3-dimensional conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Nabavizadeh, Nima, E-mail: nabaviza@ohsu.edu; Simeonova, Anna O.; Waller, Joseph G.; Romer, Jeanna L.; Monaco, Debra L.; Elliott, David A.; Tanyi, James A.; Fuss, Martin; Thomas, Charles R.; Holland, John M.

    2014-10-01

    Volumetric-modulated arc radiotherapy (VMAT) is an iteration of intensity-modulated radiotherapy (IMRT), both of which deliver highly conformal dose distributions. Studies have shown the superiority of VMAT and IMRT in comparison with 3-dimensional conformal radiotherapy (3D-CRT) in planning target volume (PTV) coverage and organs-at-risk (OARs) sparing. This is the first study examining the benefits of VMAT in pancreatic cancer for doses more than 55.8 Gy. A planning study comparing 3D-CRT, IMRT, and VMAT was performed in 20 patients with pancreatic cancer. Treatments were planned for a 25-fraction delivery of 45 Gy to a large field followed by a reduced-volume 8-fraction external beam boost to 59.4 Gy in total. OARs and PTV doses, conformality index (CI) deviations from 1.0, monitor units (MUs) delivered, and isodose volumes were compared. IMRT and VMAT CI deviations from 1.0 for the large-field and the boost plans were equivalent (large field: 0.032 and 0.046, respectively; boost: 0.042 and 0.037, respectively; p > 0.05 for all comparisons). Both IMRT and VMAT CI deviations from 1.0 were statistically superior to 3D-CRT (large field: 0.217, boost: 0.177; p < 0.05 for all comparisons). VMAT showed reduction of the mean dose to the boost PTV (VMAT: 61.4 Gy, IMRT: 62.4 Gy, and 3D-CRT: 62.3 Gy; p < 0.05). The mean number of MUs per fraction was significantly lower for VMAT for both the large-field and the boost plans. VMAT delivery time was less than 3 minutes compared with 8 minutes for IMRT. Although no statistically significant dose reduction to the OARs was identified when comparing VMAT with IMRT, VMAT showed a reduction in the volumes of the 100% isodose line for the large-field plans. Dose escalation to 59.4 Gy in pancreatic cancer is dosimetrically feasible with shorter treatment times, fewer MUs delivered, and comparable CIs for VMAT when compared with IMRT.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bedi, Meena; Firat, Selim; Semenenko, Vladimir A.; Schultz, Christopher; Tripp, Patrick; Byhardt, Roger [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Wang, Dian, E-mail: dwang@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)

    2012-05-01

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

  18. Helical tomotherapy based intensity modulated radiotherapy for the management of difficult clinical situations in breast cancer

    Directory of Open Access Journals (Sweden)

    Animesh Saha

    2015-01-01

    Full Text Available Helical tomotherapy (HT can achieve a homogenous dose distribution in the planning target volume while minimizing the dose to the organ at risk. Tomotherapy has been used for complex breast cancer radiotherapy including bilateral breast irradiation, pectus excavatum, and internal mammary chain (IMC nodal irradiation. This report details our experience of using HT in breast cancers in newer clinical indications. Three patients with SCF nodal involvement (case 1, high level III axillary node recurrence (case 2, and composite irradiation of SCF, IMC, and whole breast (case 3 were treated using brachial plexus sparing HT. It was possible to boost the SCF, reirradiate the high level III axillary nodal recurrence and treat complex volume of breast, SCF, and IMC with acceptable and safe dose volume histogram constraints and with good homogeneity and conformity indices. The treatment was successful in controlling disease locoregionally at a 15 months follow-up. No patients reported symptoms suggestive of brachial plexopathy

  19. Comparison of Heart and Coronary Artery Doses Associated With Intensity-Modulated Radiotherapy Versus Three-Dimensional Conformal Radiotherapy for Distal Esophageal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kole, Thomas P.; Aghayere, Osarhieme; Kwah, Jason [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Yorke, Ellen D. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Goodman, Karyn A., E-mail: goodmank@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2012-08-01

    Purpose: To compare heart and coronary artery radiation exposure using intensity-modulated radiotherapy (IMRT) vs. four-field three-dimensional conformal radiotherapy (3D-CRT) treatment plans for patients with distal esophageal cancer undergoing chemoradiation. Methods and Materials: Nineteen patients with distal esophageal cancers treated with IMRT from March 2007 to May 2008 were identified. All patients were treated to 50.4 Gy with five-field IMRT plans. Theoretical 3D-CRT plans with four-field beam arrangements were generated. Dose-volume histograms of the planning target volume, heart, right coronary artery, left coronary artery, and other critical normal tissues were compared between the IMRT and 3D-CRT plans, and selected parameters were statistically evaluated using the Wilcoxon rank-sum test. Results: Intensity-modulated radiotherapy treatment planning showed significant reduction (p < 0.05) in heart dose over 3D-CRT as assessed by average mean dose (22.9 vs. 28.2 Gy) and V30 (24.8% vs. 61.0%). There was also significant sparing of the right coronary artery (average mean dose, 23.8 Gy vs. 35.5 Gy), whereas the left coronary artery showed no significant improvement (mean dose, 11.2 Gy vs. 9.2 Gy), p = 0.11. There was no significant difference in percentage of total lung volume receiving at least 10, 15, or 20 Gy or in the mean lung dose between the planning methods. There were also no significant differences observed for the kidneys, liver, stomach, or spinal cord. Intensity-modulated radiotherapy achieved a significant improvement in target conformity as measured by the conformality index (ratio of total volume receiving 95% of prescription dose to planning target volume receiving 95% of prescription dose), with the mean conformality index reduced from 1.56 to 1.30 using IMRT. Conclusions: Treatment of patients with distal esophageal cancer using IMRT significantly decreases the exposure of the heart and right coronary artery when compared with 3D

  20. Intensity-modulated radiotherapy for localized nasopharyngeal amyloidosis. Case report and literature review

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Ming [Hubei University of Medicine, Department of Clinical Oncology, Taihe Hospital, Shiyan, Hubei (China); Peng, Gang; Shi, Liangliang; Li, Zhenyu; Fei, Shijiang; Ding, Qian; Cheng, Jing [HuaZhong University of Science and Technology, Cancer Center, Union Hospital, Tongji Medical College, Wuhan (China); Ming, Xing [Hubei University of Medicine, Department of infection control and prevention, Taihe Hospital, Shiyan, Hubei (China)

    2016-12-15

    Primary localized amyloidosis is characterized by the deposition of amyloid proteins restricted to one organ, without systemic involvement. Primary nasopharyngeal amyloidosis is an exceedingly rare condition, for which the standard treatment remains unknown. Because of its challenging anatomical position, surgery alone hardly results in complete resection of the localized amyloidosis. Therefore, an interdisciplinary planning board to design optimal treatment is of particular importance. A 39-year-old man presented with a several-week history of nasal obstruction and epistaxis. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed the presence of a retro-odontoid nonenhancing soft tissue mass. The endoscopic biopsy demonstrated that the mass was amyloid in nature. An extensive systemic workup revealed an absence of inflammatory process, systemic amyloidosis, or plasma cell dyscrasia. The patient was treated with a combination of surgery and radiotherapy, showing no evidence of recurrence or progression at his 1-year follow-up. Primary solitary amyloidosis is a rare form of amyloidosis. To the best of our knowledge, this is the first report of a nasopharyngeal amyloidosis case treated with excision and radiation leading to complete remission. Because of the difficulty for surgeons to achieve radical resection with such lesions, radiotherapy proved to be an excellent adjuvant treatment in this case. (orig.) [German] Die primaere lokalisierte Amyloidose ist durch die Ablagerung von Amyloidproteinen gekennzeichnet, die sich auf ein Organ beschraenkt, also nicht systemisch ist. Eine primaere Amyloidose im Nasen-Rachen-Raum ist ausserordentlich selten, bisher gibt es keine Standardtherapie. Ihre anatomische Position bedeutet eine Herausforderung, nur selten resultiert eine chirurgische Intervention in einer vollstaendigen Resektion der lokalisierten Amyloidose. Daher ist die Beteiligung mehrerer Disziplinen fuer eine optimale Behandlung von besonderer

  1. Effect of intensity-modulated pelvic radiotherapy on second cancer risk in the postoperative treatment of endometrial and cervical cancer.

    Science.gov (United States)

    Zwahlen, Daniel R; Ruben, Jeremy D; Jones, Phillip; Gagliardi, Frank; Millar, Jeremy L; Schneider, Uwe

    2009-06-01

    To estimate and compare intensity-modulated radiotherapy (IMRT) with three-dimensional conformal radiotherapy (3DCRT) in terms of second cancer risk (SCR) for postoperative treatment of endometrial and cervical cancer. To estimate SCR, the organ equivalent dose concept with a linear-exponential, a plateau, and a linear dose-response model was applied to dose distributions, calculated in a planning computed tomography scan of a 68-year-old woman. Three plans were computed: four-field 18-MV 3DCRT and nine-field IMRT with 6- and 18-MV photons. SCR was estimated as a function of target dose (50.4 Gy/28 fractions) in organs of interest according to the International Commission on Radiological Protection. Cumulative SCR relative to 3DCRT was +6% (3% for a plateau model, -4% for a linear model) for 6-MV IMRT and +26% (25%, 4%) for the 18-MV IMRT plan. For an organ within the primary beam, SCR was +12% (0%, -12%) for 6-MV and +5% (-2%, -7%) for 18-MV IMRT. 18-MV IMRT increased SCR 6-7 times for organs away from the primary beam relative to 3DCRT and 6-MV IMRT. Skin SCR increased by 22-37% for 6-MV and 50-69% for 18-MV IMRT inasmuch as a larger volume of skin was exposed. Cancer risk after IMRT for cervical and endometrial cancer is dependent on treatment energy. 6-MV pelvic IMRT represents a safe alternative with respect to SCR relative to 3DCRT, independently of the dose-response model. 18-MV IMRT produces second neutrons that modestly increase the SCR.

  2. Monte Carlo-Based Dose Calculation in Postprostatectomy Image-Guided Intensity Modulated Radiotherapy: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Ashley Rankine

    2015-01-01

    Full Text Available Step-and-shoot (S&S intensity-modulated radiotherapy (IMRT using the XiO treatment planning system (TPS has been routinely used for patients receiving postprostatectomy radiotherapy (PPRT. After installing the Monaco, a pilot study was undertaken with five patients to compare XiO with Monaco (V2.03 TPS for PPRT with respect to plan quality for S&S as well as volumetric-modulated arc therapy (VMAT. Monaco S&S showed higher mean clinical target volume (CTV coverage (99.85% than both XiO S&S (97.98%, P = 0.04 and Monaco VMAT (99.44, P = 0.02. Rectal V60Gy volumes were lower for Monaco S&S compared to XiO (46.36% versus 58.06%, P = 0.001 and Monaco VMAT (46.36% versus 54.66%, P = 0.02. Rectal V60Gy volume was lowest for Monaco S&S and superior to XiO (mean 19.89% versus 31.25%, P = 0.02. Rectal V60Gy volumes were lower for Monaco VMAT compared to XiO (21.09% versus 31.25%, P = 0.02. Other organ-at-risk (OAR parameters were comparable between TPSs. Compared to XiO S&S, Monaco S&S plans had fewer segments (78.6 versus 116.8 segments, P = 0.02, lower total monitor units (MU (677.6 MU versus 770.7 MU, P = 0.01, and shorter beam-on times (5.7 min versus 7.6 min, P = 0.03. This pilot study suggests that Monaco S&S improves CTV coverage, OAR doses, and planning and treatment times for PPRT.

  3. Dosimetric and radiobiologic comparison of 3D conformal versus intensity modulated planning techniques for prostate bed radiotherapy.

    Science.gov (United States)

    Koontz, Bridget F; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I; Montana, Gustavo S; Oleson, James R

    2009-01-01

    Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

  4. Prognostic Value of Cavernous Sinus Invasion in Patients with Nasopharyngeal Carcinoma Treated with Intensity-Modulated Radiotherapy.

    Directory of Open Access Journals (Sweden)

    Jun-Fang Liao

    Full Text Available To investigate the prognostic value of cavernoussinus invasion (CSI in patients with nasopharyngeal carcinoma (NPC treated with intensity-modulated radiotherapy (IMRT.Retrospective review of data from 1,087 patients with biopsy-proven, non-metastatic NPC. All patients were diagnosed using magnetic resonance imaging (MRI scans and received IMRT as the primary treatment.The incidence of cavernoussinus invasion in this cohort was 12.1%. In univariate analysis, 5-year overall survival (OS (70.6% vs. 88.5%, P < 0.001 and distant metastasis-free survival (DMFS (71.4% vs. 87.7%, P < 0.001, but not locoregional relapse-free survival (LRFS (93.9% vs. 93.7%, P = 0.341, were significantly different between patients with and without cavernoussinus invasion. In the T4 subgroup, the 5-year OS, DMFS, and LRFS of patients with and without cavernoussinus extension were 70.6% vs. 81.9% (P = 0.011, 71.4% vs. 84.1% (P = 0.011, and 91.2% vs. 89.7% (P = 0.501, respectively. In multivariate analysis, cavernoussinus invasion was an independent prognostic factor for poorer OS (HR = 1.782; P = 0.013 and DMFS (HR = 1.771; P = 0.016, but not LRFS (HR = 0.632; P = 0.294. In patients with lymph node metastasis, the DMFS rates of patients with and without cavernoussinus invasion were significantly different (P < 0.001. Preliminaryanalysis indicated that neoadjuvant chemotherapy led to better DMFS and OS in patients with cavernoussinus invasion than concurrent chemotherapy or radiotherapy alone; however, the differences were not significant.In the IMRT era, cavernoussinus invasion remains a prognostic factor for poor DMFS and OS in NPC, even in patients with T4 disease.

  5. 3D radiation therapy or intensity-modulated radiotherapy for recurrent and metastatic cervical cancer: the Shanghai Cancer Hospital experience.

    Directory of Open Access Journals (Sweden)

    Su-Ping Liu

    Full Text Available We evaluate the outcomes of irradiation by using three-dimensional radiation therapy (3D-RT or intensity-modulated radiotherapy (IMRT for recurrent and metastatic cervical cancer. Between 2007 and 2010, 50 patients with recurrent and metastatic cervical cancer were treated using 3D-RT or IMRT. The median time interval between the initial treatment and the start of irradiation was 12 (6-51 months. Salvage surgery was performed before irradiation in 5 patients, and 38 patients received concurrent chemotherapy. Sixteen patients underwent 3D-RT, and 34 patients received IMRT. Median follow-up for all the patients was 18.3 months. Three-year overall survival and locoregional control were 56.1% and 59.7%, respectively. Three-year progression-free survival and disease-free survival were 65.3% and 64.3%, respectively. Nine patients developed grade 3 leukopenia. Grade 5 acute toxicity was not observed in any of the patients; however, 2 patients developed Grade 3 late toxicity. 3D-RT or IMRT is effective for the treatment of recurrent and metastatic cervical cancer, with the 3-year overall survival of 56.1%, and its complications are acceptable. Long-term follow-up and further studies are needed to confirm the role of 3D-RT or IMRT in the multimodality management of the disease.

  6. Can Intensity-Modulated Radiotherapy Preserve Oral Health-Related Quality of Life of Nasopharyngeal Carcinoma Patients?

    Energy Technology Data Exchange (ETDEWEB)

    Pow, Edmond H.N., E-mail: ehnpow@hku.hk [Oral Rehabilitation, University of Hong Kong Faculty of Dentistry, Hong Kong Special Administrative Region (China); Kwong, Dora L.W.; Sham, Jonathan S.T.; Lee, Victor H.F.; Ng, Sherry C.Y. [Department of Clinical Oncology, University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong Special Administrative Region (Hong Kong)

    2012-06-01

    Purpose: To investigate the changes in salivary function and oral health-related quality of life for patients with nasopharyngeal carcinoma treated by intensity-modulated radiotherapy (IMRT). Methods and Materials: A total of 57 patients with early-stage nasopharyngeal carcinoma received IMRT. The parotid and whole saliva flow was measured, and the Medical Outcomes Study 36-item short form, European Organization for Research and Treatment of Cancer Quality of Life questionnaire-C30, European Organization for Research and Treatment of Cancer Quality of Life questionnaire 35-item head-and-neck module, and Oral Health Impact Profile questionnaires were completed at baseline and 2, 6, 12, 18, and 24 months after IMRT. Results: Parotid saliva flow recovered fully after 1 year and maintained. Whole saliva flow recovered partially to 40% of baseline. A general trend of deterioration in most quality of life scales was observed after IMRT, followed by gradual recovery. Persistent oral-related symptoms were found 2 years after treatment. Conclusion: IMRT for early-stage nasopharyngeal carcinoma could only partially preserve the whole salivary function and oral health-related quality of life.

  7. Prognostic scoring system for locoregional control among the patients with nasopharyngeal carcinoma treated by intensity-modulated radiotherapy

    Institute of Scientific and Technical Information of China (English)

    Chang-Juan Tao; Ai-Hua Lin; Jun Ma; Ying Sun; Xu Liu; Ling-Long Tang; Yan-Ping Mao; Lei Chen; Wen-Fei Li; Xiao-Li Yu; Li-Zhi Liu; Rong Zhang

    2013-01-01

    The prognostic value of T category for locoregional control in patients with nasopharyngeal carcinoma (NPC) has decreased with the extensive use of intensity-modulated radiotherapy (IMRT). We aimed to develop a prognostic scoring system (PSS) that incorporated tumor extension and clinical characteristics for locoregional control in NPC patients treated with IMRT. The magnetic resonance imaging scans and medical records of 717 patients with nonmetastatic NPC treated with IMRT at Sun Yat-sen University Cancer Center between January 2003 and January 2008 were reviewed. Age, pathologic classification, primary tumor extension, primary gross tumor volume (GTV-p), T and N categories, and baseline lactate dehydrogenase (LDH) level were analyzed. Hierarchical cluster analysis as well as univariate and multivariate analyses were used to develop the PSS. Independent prognostic factors for locoregional relapse included N2-3 stage, GTV-p≥26.8 mL, and involvement of one or more structures within cluster 3. We calculated a risk score derived from the regression coefficient of each factor and classified patients into four groups:low risk (score 0), intermediate risk (score>0 and≤1), high risk (score>1 and≤2), and extremely high risk (score>2). The 5-year locoregional control rates for these groups were 97.4%, 93.6%, 85.2%, and 78.6%, respectively (P<0.001). We have developed a PSS that can help identify NPC patients who are at high risk for locoregional relapse and can guide individualized treatments for NPC patients.

  8. Impact of obesity on outcomes after definitive dose-escalated intensity-modulated radiotherapy for localized prostate cancer.

    Science.gov (United States)

    Wang, Lora S; Murphy, Colin T; Ruth, Karen; Zaorsky, Nicholas G; Smaldone, Marc C; Sobczak, Mark L; Kutikov, Alexander; Viterbo, Rosalia; Horwitz, Eric M

    2015-09-01

    Previous publications have demonstrated conflicting results regarding body mass index (BMI) and prostate cancer (CaP) outcomes after definitive radiotherapy (RT) before the dose escalation era. The goal of the current study was to determine whether increasing BMI was associated with outcomes in men with localized CaP who were treated with dose-escalated RT. The authors identified patients with localized (T1b-T4N0M0) CaP who were treated with definitive intensity-modulated RT and image-guided RT from 2001 through 2010. BMI was analyzed as a continuous variable. Adjusting for confounders, multivariable competing risk and Cox proportional hazards regression models were used to assess the association between BMI and the risk of biochemical failure (BF), distant metastases (DM), cause-specific mortality (CSM), and overall mortality. Of the 1442 patients identified, approximately 20% had a BMI prostate-specific antigen level (P = .018). On multivariable analysis, increasing BMI was associated with an increased risk of BF (hazard ratio [HR], 1.03; 95% confidence interval [95% CI], 1.00-1.07 [P = .042]), DM (HR, 1.07; 95% CI, 1.02-1.11 [P = .004]), CSM (HR, 1.15; 95% CI, 1.07-1.23 [PCancer Society.

  9. Evaluation of the dosimetric feasibility of hippocampal sparing intensity-modulated radiotherapy in patients with locally advanced nasopharyngeal carcinoma.

    Directory of Open Access Journals (Sweden)

    Guang Han

    Full Text Available PURPOSE: The objective of this study was to evaluate the dosimetric feasibility of using hippocampus (HPC sparing intensity-modulated radiotherapy (IMRT in patients with locally advanced nasopharyngeal carcinoma (NPC. MATERIALS/METHODS: Eight cases of either T3 or T4 NPC were selected for this study. Standard IMRT treatment plans were constructed using the volume and dose constraints for the targets and organs at risk (OAR per Radiation Therapy Oncology Group (RTOG 0615 protocol. Experimental plans were constructed using the same criteria, with the addition of the HPC as an OAR. The two dose-volume histograms for each case were compared for the targets and OARs. RESULTS: All plans achieved the protocol dose criteria. The homogeneity index, conformity index, and coverage index for the planning target volumes (PTVs were not significantly compromised by the avoidance of the HPC. The doses to all OARs, excluding the HPC, were similar. Both the dose (Dmax, D2%, D40%, D mean, D median, D98% and D min and volume (V5, V10, V15, V20, V30, V40 and V50 parameters for the HPC were significantly lower in the HPC sparing plans (p<0.05, except for D min (P = 0.06 and V5 (P = 0.12. CONCLUSIONS: IMRT for patients with locally advanced NPC exposes the HPC to a significant radiation dose. HPC sparing IMRT planning significantly decreases this dose, with minimal impact on the therapeutic targets and other OARs.

  10. Dosimetric evaluation of the skin-sparing effects of 3-dimensional conformal radiotherapy and intensity-modulated radiotherapy for left breast cancer.

    Science.gov (United States)

    Jo, In Young; Kim, Shin-Wook; Son, Seok Hyun

    2017-01-10

    The purpose of this study was to evaluate the skin-sparing effects of 3-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) in patients with early left-sided breast cancer. Twenty left breast cancer patients treated with whole breast radiotherapy following breast-conserving surgery were enrolled in this study, and the 3D-CRT and IMRT plans were generated for each patient. To evaluate the dose delivered to the skin, 2 mm thickness skin (2-mm skin) and 3 mm thickness skin (3-mm skin) were contoured and a dosimetric comparison between the 2 plans was performed. The target volume coverage was better in IMRT than in 3D-CRT. The mean dose was 50.8 Gy for 3D-CRT and 51.1 Gy for IMRT. V40Gy was 99.4% for 3D-CRT and 99.9% for IMRT. In the case of skin, the mean dose was higher in 3D-CRT than in IMRT (mean dose of 2-mm skin: 32.8 Gy and 24.2 Gy; mean dose of 3-mm skin: 37.2 Gy and 27.8 Gy, for 3D-CRT and IMRT, respectively). These results indicated that the skin-sparing effect is more prominent in IMRT compared to 3D-CRT without compromising the target volume coverage.

  11. Dosimetric benefit of DMLC tracking for conventional and sub-volume boosted prostate intensity-modulated arc radiotherapy

    DEFF Research Database (Denmark)

    Pommer, Tobias; Falk, Marianne; Poulsen, Per Rugaard

    2013-01-01

    during the first 75 s. A research DMLC tracking system was used for real-time motion compensation with optical monitoring for position input. The gamma index was used for evaluation, with measurements with a static phantom or the planned dose as reference, using 2% and 2 mm gamma criteria. The average......This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose...... done with and without DMLC tracking on a linear acceleration with a high-resolution MLC. A cylindrical phantom containing two orthogonal diode arrays was used for dosimetry. A motion platform reproduced six patient-derived prostate motion traces, with the average displacement ranging from 1.0 to 8.9 mm...

  12. Serial tomotherapy vs. MLC-IMRT (Multileaf Collimator Intensity Modulated Radiotherapy) for simultaneous boost treatment large intracerebral lesions; Serielle Tomotherapie vs. MLC-IMRT (Multileaf Collimator Intensity Modulated Radiotherapy) fuer die simultane Boostbestrahlung mehrerer groesserer Hirnfiliae

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, Dirk; Lohr, Frank; Mai, Sabine; Polednik, Martin; Wenz, Frederik [Universitaetsklinikum Mannheim, Mannheim (Germany). Klinik fuer Strahlentherapie und Radioonkologie; Abo-Madyan, Yasser [Universitaetsklinikum Mannheim, Mannheim (Germany). Klinik fuer Strahlentherapie und Radioonkologie; Kasr-El-Einy Hospital. Cairo Univ. (EG). Dept. of Oncology (NEMROCK); Dobler, Barbara [Klinikum der Universitaet Regensburg (Germany). Strahlentherapie

    2009-07-01

    Introduction: Recent data suggest that a radiosurgery boost treatment for up to three brain metastases in addition to whole brain radiotherapy (WBRT) is beneficial. Sequential treatment of multiple metastatic lesions is time-consuming and optimal normal tissue sparing is not trivial for larger metastases when separate plans are created and are only superimposed afterwards. Sequential Tomotherapy with noncoplanar arcs and Multi-field IMRT may streamline the process and enable easy simultaneous treatment. We compared plans for 2-3 intracerebral targets calculated with Intensity Modulated Radiotherapy (IMRT) based on treatment with MLC or sequential Tomotherapy using the Peacock-System. Treatment time was not to exceed 90 min on a linac with standart dose rate. MIMiC plans without treatment-time restrictions were created as a benchmark. Materials and methods: Calculations are based on a Siemens KD2 linac with a dose rate of 200 MU/min. Step-and-Shoot IMRT is performed with a standard MLC (2 x 29 leaves, 1 cm), serial Tomotherapy with the Multivane-Collimator MIMiC (NOMOS Inc. USA). Treatment plans are created with Corvus 5.0. To create plans with good conformity we chose a noncoplanar beam- and arc geometry for each approach (IMRT 4-, MIMiC 5-couch angles). The benchmark MIMiC plans with maximally steep dose gradients had 9 couch angles. For plan comparison reasons, 10Gy were prescribed to 90% of the PTV. Steepness of dose gradients, homogeneity and conformity were assessed by the following parameters: Volume encompassed by certain isodoses outside the target as well as homogeneity and conformity as indicated by Homogeneity- and Conformity-Index. Results: Plans without treatment-time restrictions had slightest dose to organ at risk (OAR), normal tissue and least Conformity-index. MIMiC- and MLC-IMRT based plans can be treated within the intended period of 90 min, all plans met the required dose. MLC based plans resulted in higher dose to organs at risk (OAR) and dose

  13. Intensity-modulated radiotherapy vs. parotid-sparing 3D conformal radiotherapy. Effect on outcome and toxicity in locally advanced head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lambrecht, M.; Nevens, D.; Nuyts, S. [University Hospitals Leuven (Belgium). Dept. of Radiation Oncology

    2013-03-15

    Background and purpose: Intensity-modulated radiotherapy (IMRT) has rapidly become standard of care in the management of locally advanced head and neck squamous cell carcinoma (HNSCC). In this study, our aim was to retrospectively investigate the effect of the introducing IMRT on outcome and treatment-related toxicity compared to parotid-sparing 3D conformal radiotherapy (3DCRT). Material and methods: A total of 245 patients with stage III and IV HNSCC treated with primary radiotherapy between January 2003 and December 2010 were included in this analysis: 135 patients were treated with 3DCRT, 110 patients with IMRT. Groups were compared for acute and late toxicity, locoregional control (LRC), and overall survival (OS). Oncologic outcomes were estimated using Kaplan-Meier analysis and compared using a log-rank test. Acute toxicity was analyzed according to the Common Terminology Criteria for Adverse Events v3.0 and late toxicity was scored using the RTOG/EORTC late toxicity scoring system. Results: Median follow-up was 35 months in the IMRT group and 68 months in the 3DCRT group. No significant differences were found in 3-year LRC and OS rates between the IMRT group and 3DCRT group. Significantly less acute mucositis {>=} grade 3 was observed in the IMRT group (32% vs. 44%, p = 0.03). There was significantly less late xerostomia {>=} grade 2 in the IMRT group than in the 3DCRT group (23% vs. 68%, p < 0.001). After 24 months, there was less dysphagia {>=} grade 2 in the IMRT group although differences failed to reach statistical significance. Conclusion: The introduction of IMRT in the radiotherapeutic management of locally advanced head and neck cancer significantly improved late toxicity without compromising tumor control compared to a parotid-sparing 3D conformal radiotherapy technique. (orig.)

  14. Radiobiologic comparison of helical tomotherapy, intensity modulated radiotherapy, and conformal radiotherapy in treating lung cancer accounting for secondary malignancy risks

    Energy Technology Data Exchange (ETDEWEB)

    Komisopoulos, Georgios [Department of Medical Physics, Medical School, University of Patras, Patras (Greece); Mavroidis, Panayiotis, E-mail: mavroidis@uthscsa.edu [Department of Radiation Oncology, University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States); Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, Stockholm (Sweden); Rodriguez, Salvador; Stathakis, Sotirios; Papanikolaou, Nikos [Department of Radiation Oncology, University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States); Nikiforidis, Georgios C.; Sakellaropoulos, Georgios C. [Department of Medical Physics, Medical School, University of Patras, Patras (Greece)

    2014-01-01

    The aim of the present study is to examine the importance of using measures to predict the risk of inducing secondary malignancies in association with the clinical effectiveness of treatment plans in terms of tumor control and normal tissue complication probabilities. This is achieved by using radiobiologic parameters and measures, which may provide a closer association between clinical outcome and treatment delivery. Overall, 4 patients having been treated for lung cancer were examined. For each of them, 3 treatment plans were developed based on the helical tomotherapy (HT), multileaf collimator-based intensity modulated radiation therapy (IMRT), and 3-dimensional conformal radiation therapy (CRT) modalities. The different plans were evaluated using the complication-free tumor control probability (p{sub +}), the overall probability of injury (p{sub I}), the overall probability of control/benefit (p{sub B}), and the biologically effective uniform dose (D{sup ¯¯}). These radiobiologic measures were used to develop dose-response curves (p-D{sup ¯¯} diagram), which can help to evaluate different treatment plans when used in conjunction with standard dosimetric criteria. The risks for secondary malignancies in the heart and the contralateral lung were calculated for the 3 radiation modalities based on the corresponding dose-volume histograms (DVHs) of each patient. Regarding the overall evaluation of the different radiation modalities based on the p{sub +} index, the average values of the HT, IMRT, and CRT are 67.3%, 61.2%, and 68.2%, respectively. The corresponding average values of p{sub B} are 75.6%, 70.5%, and 71.0%, respectively, whereas the average values of p{sub I} are 8.3%, 9.3%, and 2.8%, respectively. Among the organs at risk (OARs), lungs show the highest probabilities for complications, which are 7.1%, 8.0%, and 1.3% for the HT, IMRT, and CRT modalities, respectively. Similarly, the biologically effective prescription doses (D{sub B}{sup ¯¯}) for the

  15. The Evolution of and Risk Factors for Neck Muscle Atrophy and Weakness in Nasopharyngeal Carcinoma Treated With Intensity-Modulated Radiotherapy

    OpenAIRE

    Zhang, Lu-lu; Mao, Yan-Ping; Zhou, Guan-Qun; Tang, Ling-Long; Qi, Zhen-Yu; Lin, Li; Yao, Ji-Jin; Ma, Jun; Lin, Ai-Hua; Sun, Ying

    2015-01-01

    Abstract The aim of this study was to investigate the evolution of sternocleidomastoid muscle (SCM) atrophy in nasopharyngeal carcinoma (NPC) patients following intensity-modulated radiotherapy (IMRT), and the relationship between SCM atrophy and neck weakness. Data were retrospectively analyzed from 223 biopsy-proven NPC patients with no distant metastasis who underwent IMRT with or without chemotherapy. The volume of SCM was measured on pretreatment magnetic resonance imaging (MRI), and MRI...

  16. Predictors of acute toxicities during definitive chemoradiation using intensity-modulated radiotherapy for anal squamous cell carcinoma.

    Science.gov (United States)

    Julie, Diana A R; Oh, Jung Hun; Apte, Aditya P; Deasy, Joseph O; Tom, Ashlyn; Wu, Abraham J; Goodman, Karyn A

    2016-01-01

    To identify clinical and dosimetric factors associated with acute hematologic and gastrointestinal (GI) toxicities during definitive therapy using intensity-modulated radiotherapy (IMRT) for anal squamous cell carcinoma (ASCC). We retrospectively analyzed 108 ASCC patients treated with IMRT. Clinical information included age, gender, stage, concurrent chemotherapy, mitomycin (MMC) chemotherapy and weekly hematologic and GI toxicity during IMRT. From contours of the bony pelvis and bowel, dose-volume parameters were extracted. Logistic regression models were used to test associations between toxicities and clinical or dosimetric predictors. The median age was 59 years, 81 patients were women and 84 patients received concurrent MMC and 5-fluorouracil (5FU). On multivariate analysis (MVA), the model most predictive of Grade 2 + anemia included the maximum bony pelvis dose (Dmax), female gender, and T stage [p = 0.035, cross validation area under the curve (cvAUC) = 0.66]. The strongest model of Grade 2 + leukopenia included V10 (percentage of pelvic bone volume receiving ≥ 10 Gy) and number of MMC cycles (p = 0.276, cvAUC = 0.57). The model including MMC cycle number and T stage correlated best with Grade 2 + neutropenia (p = 0.306, cvAUC = 0.57). The model predictive of combined Grade 2 + hematologic toxicity (HT) included V10 and T stage (p = 0.016, cvAUC = 0.66). A model including VA45 (absolute bowel volume receiving ≥ 45 Gy) and MOH5 (mean dose to hottest 5% of bowel volume) best predicted diarrhea (p = 0.517, cvAUC = 0.56). Dosimetric constraints to the pelvic bones should be integrated into IMRT planning to reduce toxicity, potentially reducing treatment interruptions and improving disease outcomes in ASCC. Specifically, our results indicate that Dmax should be confined to ≤ 57 Gy to minimize anemia and that V10 should be restricted to ≤ 87% to reduce incidence of all HT.

  17. Australasian Gastrointestinal Trials Group (AGITG) Contouring Atlas and Planning Guidelines for Intensity-Modulated Radiotherapy in Anal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Michael, E-mail: mng@radoncvic.com.au [Radiation Oncology Victoria, Victoria (Australia); Leong, Trevor [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Victoria (Australia); University of Melbourne (Australia); Chander, Sarat; Chu, Julie [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Victoria (Australia); Kneebone, Andrew [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, NSW (Australia); University of Sydney (Australia); Carroll, Susan [Department of Radiation Oncology, Sydney Cancer Centre, Royal Prince Alfred Hospital, NSW (Australia); University of Sydney (Australia); Wiltshire, Kirsty [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Victoria (Australia); Ngan, Samuel [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Victoria (Australia); University of Melbourne (Australia); Kachnic, Lisa [Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, MA (United States)

    2012-08-01

    Purpose: To develop a high-resolution target volume atlas with intensity-modulated radiotherapy (IMRT) planning guidelines for the conformal treatment of anal cancer. Methods and Materials: A draft contouring atlas and planning guidelines for anal cancer IMRT were prepared at the Australasian Gastrointestinal Trials Group (AGITG) annual meeting in September 2010. An expert panel of radiation oncologists contoured an anal cancer case to generate discussion on recommendations regarding target definition for gross disease, elective nodal volumes, and organs at risk (OARs). Clinical target volume (CTV) and planning target volume (PTV) margins, dose fractionation, and other IMRT-specific issues were also addressed. A steering committee produced the final consensus guidelines. Results: Detailed contouring and planning guidelines and a high-resolution atlas are provided. Gross tumor and elective target volumes are described and pictorially depicted. All elective regions should be routinely contoured for all disease stages, with the possible exception of the inguinal and high pelvic nodes for select, early-stage T1N0. A 20-mm CTV margin for the primary, 10- to 20-mm CTV margin for involved nodes and a 7-mm CTV margin for the elective pelvic nodal groups are recommended, while respecting anatomical boundaries. A 5- to 10-mm PTV margin is suggested. When using a simultaneous integrated boost technique, a dose of 54 Gy in 30 fractions to gross disease and 45 Gy to elective nodes with chemotherapy is appropriate. Guidelines are provided for OAR delineation. Conclusion: These consensus planning guidelines and high-resolution atlas complement the existing Radiation Therapy Oncology Group (RTOG) elective nodal ano-rectal atlas and provide additional anatomic, clinical, and technical instructions to guide radiation oncologists in the planning and delivery of IMRT for anal cancer.

  18. Level IB nodal involvement in oropharyngeal carcinoma: implications for submandibular gland-sparing intensity-modulated radiotherapy.

    Science.gov (United States)

    Yu, Yao; Daly, Megan E; Farwell, D Gregory; Luu, Quang; Gandour-Edwards, Regina; Donald, Paul J; Chen, Allen M

    2015-03-01

    Submandibular gland-sparing intensity-modulated radiotherapy (SMG-sparing IMRT) has been proposed to reduce xerostomia following head and neck irradiation. However, the safety of this practice has been questioned. Data from a large surgical series of oropharyngeal carcinoma patients were extracted to identify clinicopathological correlates for submandibular involvement and to create a risk stratification scheme to guide decision making to refine selection guidelines for SMG-sparing IMRT. Clinicopathologic analysis. The medical records of 153 consecutive patients with squamous cell carcinoma of the oropharynx treated by primary surgery and neck dissection were reviewed. Univariate and multivariate analysis was performed with logistic regression to identify factors predictive of submandibular involvement. Recursive partitioning was used to develop risk stratification schemas based on preoperative data alone and in combination with pathologic data to guide treatment decisions in the definitive and postoperative settings, respectively. Submandibular (level IB) nodal dissection was performed in 119 heminecks (85 ipsilateral and 17 contralateral). The incidence of submandibular involvement was 18%. Young age, T3-4 disease, N2b-3 disease, and perineural invasion were identified as risk factors for submandibular nodal involvement on multivariate analysis (P 60 years and N0-2a disease (low risk, 2%), age ≤60 years and T1-2N2b-3 (intermediate risk, 16%), age ≤60 years and T3-4N2b-3 disease (high risk, 57%). These data provide assurances that SMG-sparing IMRT can reasonably be offered to appropriately selected patients. Risk stratification schemas were successfully developed for SMG-sparing IMRT in both the definitive and adjuvant settings. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  19. SU-E-T-617: Plan Quality Estimation of Intensity-Modulated Radiotherapy Cases for Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Koo, J; Yoon, M [Korea University, Seoul (Korea, Republic of); Chung, W; Kim, D [Kyung Hee University Hospital at Gangdong, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: To estimate the planning quality of intensity-modulated radiotherapy in lung cancer cases and to provide preliminary data for the development of a planning quality assurance algorithm. Methods: 42 IMRT plans previously used in cases of solitary lung cancers were collected. Organs in or near the thoracic cavity, such as lung (ipsilateral, contralateral), heart, liver, esophagus, cord and bronchus were considered as organs at risk (OARs) in this study. The coverage index (CVI), conformity index (CI), homogeneity index (HI), volume, irregularity (standard deviation of center-surface distance) were used to compare PTV dose characteristics. The effective uniform dose (EUD), V10Gy, and V20Gy of the OARs were used to compare OAR dose characteristics. Results: Average CVI, CI, HI values were 0.9, 0.8, 0.1, respectively. CVI and CI had narrow Gaussian distribution curves without a singular value, but one case had a relatively high (0.25) HI because of location and irregular shape (Irregularity of 18.5 when average was 12.5) of PTV. EUDs tended to decrease as OAR-PTV distance increased and OAR-PTV overlap volume decreased. Conclusion: This work indicates the potential for significant plan quality deviation of similar lung cancer cases. Considering that this study were from a single department, differences in the treatment results for a given patient would be much more pronounced if multiple departments (and therefore more planners) were involved. Therefore, further examination of QA protocols is needed to reduce deviations in radiation treatment planning.

  20. Intensity-Modulated Radiotherapy for Tumors of the Nasal Cavity and Paranasal Sinuses: Clinical Outcomes and Patterns of Failure

    Energy Technology Data Exchange (ETDEWEB)

    Wiegner, Ellen A.; Daly, Megan E.; Murphy, James D.; Abelson, Jonathan; Chapman, Chris H.; Chung, Melody; Yu, Yao; Colevas, A. Dimitrios; Kaplan, Michael J.; Fischbein, Nancy; Le, Quynh-Thu [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Chang, Daniel T., E-mail: dtchang@stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, CA (United States)

    2012-05-01

    Purpose: To report outcomes in patients treated with intensity-modulated radiotherapy (IMRT) for tumors of the paranasal sinuses and nasal cavity (PNS/NC). Methods/Materials: Between June 2000 and December 2009, 52 patients with tumors of the PNS/NC underwent postoperative or definitive radiation with IMRT. Twenty-eight (54%) patients had squamous cell carcinoma (SCC). Twenty-nine patients (56%) received chemotherapy. The median follow-up was 26.6 months (range, 2.9-118.4) for all patients and 30.9 months for living patients. Results: Eighteen patients (35%) developed local-regional failure (LRF) at median time of 7.2 months. Thirteen local failures (25%) were observed, 12 in-field and 1 marginal. Six regional failures were observed, two in-field and four out-of-field. No patients treated with elective nodal radiation had nodal regional failure. Two-year local-regional control (LRC), in-field LRC, freedom from distant metastasis (FFDM), and overall survival (OS) were 64%, 74%, 71%, and 66% among all patients, respectively, and 43%, 61%, 61%, and 53% among patients with SCC, respectively. On multivariate analysis, SCC and >1 subsite involved had worse LRC (p = 0.0004 and p = 0.046, respectively) and OS (p = 0.003 and p = 0.046, respectively). Cribriform plate invasion (p = 0.005) and residual disease (p = 0.047) also had worse LRC. Acute toxicities included Grade {>=}3 mucositis in 19 patients (37%), and Grade 3 dermatitis in 8 patients (15%). Six patients had Grade {>=}3 late toxicity including one optic toxicity. Conclusions: IMRT for patients with PNS/NC tumors has good outcomes compared with historical series and is well tolerated. Patients with SCC have worse LRC and OS. LRF is the predominant pattern of failure.

  1. Intensity modulated radiotherapy for localized prostate cancer: rigid compliance to dose-volume constraints as a warranty of acceptable toxicity?

    Directory of Open Access Journals (Sweden)

    Moreira Frederico R

    2007-01-01

    Full Text Available Abstract Background To report the toxicity after intensity modulated radiotherapy (IMRT for patients with localized prostate cancer, as a sole treatment or after radical prostatectomy. Methods Between August 2001 and December 2003, 132 patients with prostate cancer were treated with IMRT and 125 were evaluable to acute and late toxicity analysis, after a minimum follow-up time of one year. Clinical and treatment data, including normal tissue dose-volume histogram (DVH constraints, were reviewed. Gastro-intestinal (GI and genito-urinary (GU signs and symptoms were evaluated according to the Radiation Therapy Oncology Group (RTOG toxicity scales. Median prescribed dose was 76 Gy. Median follow-up time was of 26.1 months. Results From the 125 patients, 73 (58.4% presented acute Grade 1 or Grade 2 GI and 97 (77.2% presented acute Grade 1 or Grade 2 GU toxicity. Grade 3 GI acute toxicity occurred in only 2 patients (1.6% and Grade 3 GU acute toxicity in only 3 patients (2.4%. Regarding Grade 1 and 2 late toxicity, 26 patients (20.8% and 21 patients (16.8% presented GI and GU toxicity, respectively. Grade 2 GI late toxicity occurred in 6 patients (4.8% and Grade 2 GU late toxicity in 4 patients (3.2%. None patient presented any Grade 3 or higher late toxicity. Non-conformity to DVH constraints occurred in only 11.2% of treatment plans. On univariate analysis, no significant risk factor was identified for Grade 2 GI late toxicity, but mean dose delivered to the PTV was associated to higher Grade 2 GU late toxicity (p = 0.042. Conclusion IMRT is a well tolerable technique for routine treatment of localized prostate cancer, with short and medium-term acceptable toxicity profiles. According to the data presented here, rigid compliance to DHV constraints might prevent higher incidences of normal tissue complication.

  2. WE-G-BRF-01: Adaptation to Intrafraction Tumor Deformation During Intensity-Modulated Radiotherapy: First Proof-Of-Principle Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Y; OBrien, R; Shieh, C; Booth, J; Keall, P [Radiation Physics Laboratory, University of Sydney (Australia)

    2014-06-15

    Purpose: Intrafraction tumor deformation limits targeting accuracy in radiotherapy and cannot be adapted to by current motion management techniques. This study simulated intrafractional treatment adaptation to tumor deformations using a dynamic Multi-Leaf Collimator (DMLC) tracking system during Intensity-modulated radiation therapy (IMRT) treatment for the first time. Methods: The DMLC tracking system was developed to adapt to the intrafraction tumor deformation by warping the planned beam aperture guided by the calculated deformation vector field (DVF) obtained from deformable image registration (DIR) at the time of treatment delivery. Seven single phantom deformation images up to 10.4 mm deformation and eight tumor system phantom deformation images up to 21.5 mm deformation were acquired and used in tracking simulation. The intrafraction adaptation was simulated at the DMLC tracking software platform, which was able to communicate with the image registration software, reshape the instantaneous IMRT field aperture and log the delivered MLC fields.The deformation adaptation accuracy was evaluated by a geometric target coverage metric defined as the sum of the area incorrectly outside and inside the reference aperture. The incremental deformations were arbitrarily determined to take place equally over the delivery interval. The geometric target coverage of delivery with deformation adaptation was compared against the delivery without adaptation. Results: Intrafraction deformation adaptation during dynamic IMRT plan delivery was simulated for single and system deformable phantoms. For the two particular delivery situations, over the treatment course, deformation adaptation improved the target coverage by 89% for single target deformation and 79% for tumor system deformation compared with no-tracking delivery. Conclusion: This work demonstrated the principle of real-time tumor deformation tracking using a DMLC. This is the first step towards the development of an

  3. A comparison of liver protection among 3-D conformal radiotherapy, intensity-modulated radiotherapy and RapidArc for hepatocellular carcinoma

    Science.gov (United States)

    2014-01-01

    Purpose The analysis was designed to compare dosimetric parameters among 3-D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and RapidArc (RA) to identify which can achieve the lowest risk of radiation-induced liver disease (RILD) for hepatocellular carcinoma (HCC). Methods Twenty patients with HCC were enrolled in this study. Dosimetric values for 3DCRT, IMRT, and RA were calculated for total dose of 50 Gy/25f. The percentage of the normal liver volume receiving >40, >30, >20, >10, and >5 Gy (V40, V30, V20, V10 and V5) were evaluated to determine liver toxicity. V5, V10, V20, V30 and Dmean of liver were compared as predicting parameters for RILD. Other parameters included the conformal index (CI), homogeneity index (HI), and hot spot (V110%) for the planned target volume (PTV) as well as the monitor units (MUs) for plan efficiency, the mean dose (Dmean) for the organs at risk (OARs) and the maximal dose at 1% volume (D1%) for the spinal cord. Results The Dmean of IMRT was higher than 3DCRT (p = 0.045). For V5, there was a significant difference: RA > IMRT >3DCRT (p delivery time than 3DCRT or IMRT (p 8 cm in our study, the value of Dmean for 3DCRT was lower than IMRT or RapidArc. This may indicate that 3DCRT is more suitable for larger tumors. PMID:24502643

  4. Tumor Control Outcomes After Hypofractionated and Single-Dose Stereotactic Image-Guided Intensity-Modulated Radiotherapy for Extracranial Metastases From Renal Cell Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Greco, Carlo [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Motzer, Robert [Solid Tumor Service, Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Magsanoc, Juan Martin; Pei Xin [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Lovelock, Michael; Mechalakos, Jim [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Zatcky, Joan; Fuks, Zvi; Yamada, Yoshiya [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2012-04-01

    Purpose: To report tumor local progression-free outcomes after treatment with single-dose, image-guided, intensity-modulated radiotherapy and hypofractionated regimens for extracranial metastases from renal cell primary tumors. Patients and Methods: Between 2004 and 2010, 105 lesions from renal cell carcinoma were treated with either single-dose, image-guided, intensity-modulated radiotherapy to a prescription dose of 18-24 Gy (median, 24) or hypofractionation (three or five fractions) with a prescription dose of 20-30 Gy. The median follow-up was 12 months (range, 1-48). Results: The overall 3-year actuarial local progression-free survival for all lesions was 44%. The 3-year local progression-free survival for those who received a high single-dose (24 Gy; n = 45), a low single-dose (<24 Gy; n = 14), or hypofractionation regimens (n = 46) was 88%, 21%, and 17%, respectively (high single dose vs. low single dose, p = .001; high single dose vs. hypofractionation, p < .001). Multivariate analysis revealed the following variables were significant predictors of improved local progression-free survival: 24 Gy dose compared with a lower dose (p = .009) and a single dose vs. hypofractionation (p = .008). Conclusion: High single-dose, image-guided, intensity-modulated radiotherapy is a noninvasive procedure resulting in high probability of local tumor control for metastatic renal cell cancer generally considered radioresistant according to the classic radiobiologic ranking.

  5. Phase I Trial of Hypofractionated Intensity-Modulated Radiotherapy With Temozolomide Chemotherapy for Patients With Newly Diagnosed Glioblastoma Multiforme

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    Chen Changhu, E-mail: changhu.chen@ucdenver.edu [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO (United States); Damek, Denise [Department of Neurology, University of Colorado School of Medicine, Aurora, CO (United States); Gaspar, Laurie E. [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO (United States); Waziri, Allen; Lillehei, Kevin [Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO (United States); Kleinschmidt-DeMasters, B.K. [Department of Pathology, University of Colorado School of Medicine, Aurora, CO (United States); Robischon, Monica; Stuhr, Kelly; Rusthoven, Kyle E.; Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO (United States)

    2011-11-15

    Purpose: To determine the maximal tolerated biologic dose intensification of radiotherapy using fractional dose escalation with temozolomide (TMZ) chemotherapy in patients with newly diagnosed glioblastoma multiforme. Methods and Materials: Patients with newly diagnosed glioblastoma multiforme after biopsy or resection and with adequate performance status, bone marrow, and organ function were eligible. The patients underwent postoperative intensity-modulated radiotherapy (IMRT) with concurrent and adjuvant TMZ. All patients received a total dose of 60 Gy to the surgical cavity and residual tumor, with a 5-mm margin. IMRT biologic dose intensification was achieved by escalating from 3 Gy/fraction (Level 1) to 6 Gy/fraction (Level 4) in 1-Gy increments. Concurrent TMZ was given at 75 mg/m{sup 2}/d for 28 consecutive days. Adjuvant TMZ was given at 150-200 mg/m{sup 2}/d for 5 days every 28 days. Dose-limiting toxicity was defined as any Common Terminology Criteria for Adverse Events, version 3, Grade 3-4 nonhematologic toxicity, excluding Grade 3 fatigue, nausea, and vomiting. A standard 3+3 Phase I design was used. Results: A total of 16 patients were accrued (12 men and 4 women, median age, 69 years; range, 34-84. The median Karnofsky performance status was 80 (range, 60-90). Of the 16 patients, 3 each were treated at Levels 1 and 2, 4 at Level 3, and 6 at Level 4. All patients received IMRT and concurrent TMZ according to the protocol, except for 1 patient, who received 14 days of concurrent TMZ. The median number of adjuvant TMZ cycles was 7.5 (range, 0-12). The median survival was 16.2 months (range, 3-33). One patient experienced vision loss in the left eye 7 months after IMRT. Four patients underwent repeat surgery for suspected tumor recurrence 6-12 months after IMRT; 3 had radionecrosis. Conclusions: The maximal tolerated IMRT fraction size was not reached in our study. Our results have shown that 60 Gy IMRT delivered in 6-Gy fractions within 2 weeks with

  6. Intensity modulated radiotherapy for high risk prostate cancer based on sentinel node SPECT imaging for target volume definition

    Directory of Open Access Journals (Sweden)

    Anastasiadis Aristotelis

    2005-07-01

    Full Text Available Abstract Background The RTOG 94-13 trial has provided evidence that patients with high risk prostate cancer benefit from an additional radiotherapy to the pelvic nodes combined with concomitant hormonal ablation. Since lymphatic drainage of the prostate is highly variable, the optimal target volume definition for the pelvic lymph nodes is problematic. To overcome this limitation, we tested the feasibility of an intensity modulated radiation therapy (IMRT protocol, taking under consideration the individual pelvic sentinel node drainage pattern by SPECT functional imaging. Methods Patients with high risk prostate cancer were included. Sentinel nodes (SN were localised 1.5–3 hours after injection of 250 MBq 99mTc-Nanocoll using a double-headed gamma camera with an integrated X-Ray device. All sentinel node localisations were included into the pelvic clinical target volume (CTV. Dose prescriptions were 50.4 Gy (5 × 1.8 Gy / week to the pelvis and 70.0 Gy (5 × 2.0 Gy / week to the prostate including the base of seminal vesicles or whole seminal vesicles. Patients were treated with IMRT. Furthermore a theoretical comparison between IMRT and a three-dimensional conformal technique was performed. Results Since 08/2003 6 patients were treated with this protocol. All patients had detectable sentinel lymph nodes (total 29. 4 of 6 patients showed sentinel node localisations (total 10, that would not have been treated adequately with CT-based planning ('geographical miss' only. The most common localisation for a probable geographical miss was the perirectal area. The comparison between dose-volume-histograms of IMRT- and conventional CT-planning demonstrated clear superiority of IMRT when all sentinel lymph nodes were included. IMRT allowed a significantly better sparing of normal tissue and reduced volumes of small bowel, large bowel and rectum irradiated with critical doses. No gastrointestinal or genitourinary acute toxicity Grade 3 or 4 (RTOG

  7. SU-E-T-608: Performance Comparison of Four Commercial Treatment Planning Systems Applied to Intensity-Modulated Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Y; Li, R; Chi, Z [The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, CN, Shijiazhuang, Hebei (China)

    2014-06-01

    Purpose: To compare the performances of four commercial treatment planning systems (TPS) used for the intensity-modulated radiotherapy (IMRT). Methods: Ten patients of nasopharyngeal (4 cases), esophageal (3 cases) and cervical (3 cases) cancer were randomly selected from a 3-month IMRT plan pool at one radiotherapy center. For each patient, four IMRT plans were newly generated by using four commercial TPS (Corvus, Monaco, Pinnacle and Xio), and then verified with Matrixx (two-dimensional array/IBA Company) on Varian23EX accelerator. A pass rate (PR) calculated from the Gamma index by OminiPro IMRT 1.5 software was evaluated at four plan verification standards (1%/1mm, 2%/2mm, 3%/3mm, 4%/4mm and 5%/5mm) for each treatment plan. Overall and multiple pairwise comparisons of PRs were statistically conducted by analysis of covariance (ANOVA) F and LSD tests among four TPSs. Results: Overall significant (p>0.05) differences of PRs were found among four TPSs with F test values of 3.8 (p=0.02), 21.1(>0.01), 14.0 (>0.01), 8.3(>0.01) at standards of 1%/1mm to 4%/4mm respectively, except at 5%/5mm standard with 2.6 (p=0.06). All means (standard deviation) of PRs at 3%/3mm of 94.3 ± 3.3 (Corvus), 98.8 ± 0.8 (Monaco), 97.5± 1.7 (Pinnacle), 98.4 ± 1.0 (Xio) were above 90% and met clinical requirement. Multiple pairwise comparisons had not demonstrated a consistent low or high pattern on either TPS. Conclusion: Matrixx dose verification results show that the validation pass rates of Monaco and Xio plans are relatively higher than those of the other two; Pinnacle plan shows slight higher pass rate than Corvus plan; lowest pass rate was achieved by the Corvus plan among these four kinds of TPS.

  8. Reducing the risk of xerostomia and mandibular osteoradionecrosis: the potential benefits of intensity modulated radiotherapy in advanced oral cavity carcinoma.

    Science.gov (United States)

    Ahmed, Merina; Hansen, Vibeke N; Harrington, Kevin J; Nutting, Christopher M

    2009-01-01

    Radiation therapy for squamous cell carcinoma of the oral cavity may be curative, but carries a risk of permanent damage to bone, salivary glands, and other soft tissues. We studied the potential of intensity modulated radiotherapy (IMRT) to improve target volume coverage, and normal tissue sparing for advanced oral cavity carcinoma (OCC). Six patients with advanced OCC requiring bilateral irradiation to the oral cavity and neck were studied. Standard 3D conformal radiotherapy (3DCRT) and inverse-planned IMRT dose distributions were compared by using dose-volume histograms. Doses to organs at risk, including spinal cord, parotid glands, and mandible, were assessed as surrogates of radiation toxicity. PTV1 mean dose was 60.8 +/- 0.8 Gy for 3DCRT and 59.8 +/- 0.1 Gy for IMRT (p = 0.04). PTV1 dose range was 24.7 +/- 6 Gy for 3DCRT and 15.3 +/- 4 Gy for IMRT (p = 0.001). PTV2 mean dose was 54.5 +/- 0.8 Gy for 3DCRT and for IMRT was 54.2 +/- 0.2 Gy (p = 0.34). PTV2 dose range was improved by IMRT (7.8 +/- 3.2 Gy vs. 30.7 +/- 12.8 Gy, p = 0.006). Homogeneity index (HI) values for PTV2 were closer to unity using IMRT (p = 0.0003). Mean parotid doses were 25.6 +/- 2.7 Gy for IMRT and 42.0 +/- 8.8 Gy with 3DCRT (p = 0.002). The parotid V30 in all IMRT plans was <45%. The mandible V50, V55, and V60 were significantly lower for the IMRT plans. Maximum spinal cord and brain stem doses were similar for the 2 techniques. IMRT provided superior target volume dose homogeneity and sparing of organs at risk. The magnitude of reductions in dose to the salivary glands and mandible are likely to translate into reduced incidence of xerostomia and osteoradionecrosis for patients with OCC.

  9. Adjuvant external beam radiotherapy after therapeutic groin lymphadenectomy for patients with melanoma: a dosimetric comparison of three-dimensional conformal and intensity-modulated radiotherapy techniques.

    Science.gov (United States)

    Adams, Gerard; Foote, Matthew; Brown, Simon; Burmeister, Bryan

    2017-02-01

    Radiotherapy after lymph node dissection is recommended in high-risk melanoma cases. The aim of this study is to assess whether intensity-modulated radiotherapy (IMRT) offers advantages over three-dimensional conformal radiotherapy (3DCRT) in the groin nodal basin. Fifteen consecutively treated patients (5 3DCRT and 10 IMRT) were selected. Optimized theoretical plans using the other modality were created - enabling direct comparisons of 3DCRT and IMRT. Target volume and organs at risk constraints were assessed as achieved or as having minor (≤5%) or major (>5%) deviations. The Wilcoxon signed-rank test was used to compare the dose received from each patient plan (3DCRT vs. IMRT), whereas the Mann-Whitney U-test was used to compare clinical plans with theoretical plans. Fisher's exact test was used to compare categorical data. Target coverage was achievable in most patients (major deviations - 1 IMRT and 3 3DCRT). Conformity index improved with IMRT - median 0.65, range 0.48-0.81, versus median 0.44, range 0.29-0.60 for 3DCRT; P value less than 0.001. All 3DCRT plans had major deviations for femoral head/neck constraints. Twelve and 13 IMRT plans achieved the high (V42numbers used nor dosimetric endpoints measured when clinical plans were compared with theoretical plans. IMRT appears to allow superior conformity of dose to the target volume while relatively sparing the adjacent the bowel and femoral head/neck. This may reduce toxicity while maintaining control rates.

  10. Dosimetric Evaluation of Intensity-Modulated Radiotherapy, Volumetric Modulated Arc Therapy, and Helical Tomotherapy for Hippocampal-Avoidance Whole Brain Radiotherapy

    Science.gov (United States)

    Rong, Yi; Evans, Josh; Xu-Welliver, Meng; Pickett, Cadron; Jia, Guang; Chen, Quan; Zuo, Li

    2015-01-01

    Background Whole brain radiotherapy (WBRT) is a vital tool in radiation oncology and beyond, but it can result in adverse health effects such as neurocognitive decline. Hippocampal Avoidance WBRT (HA-WBRT) is a strategy that aims to mitigate the neuro-cognitive side effects of whole brain radiotherapy treatment by sparing the hippocampi while delivering the prescribed dose to the rest of the brain. Several competing modalities capable of delivering HA-WBRT, include: Philips Pinnacle step-and-shoot intensity modulated radiotherapy (IMRT), Varian RapidArc volumetric modulated arc therapy (RapidArc), and helical TomoTherapy (TomoTherapy). Methods In this study we compared these methods using 10 patient datasets. Anonymized planning CT (computerized tomography) scans and contour data based on fused MRI images were collected. Three independent planners generated treatment plans for the patients using three modalities, respectively. All treatment plans met the RTOG 0933 criteria for HA-WBRT treatment. Results In dosimetric comparisons between the three modalities, TomoTherapy has a significantly superior homogeneity index of 0.15 ± 0.03 compared to the other two modalities (0.28 ± .04, p delivery time of 2.5 min compared to the other modalities (15 min for IMRT and 18 min for TomoTherapy). Conclusion TomoTherapy is considered to be the preferred modality for HA-WBRT due to its superior dose distribution. When TomoTherapy is not available or treatment time is a concern, RapidArc can provide sufficient dose distribution meeting RTOG criteria and efficient treatment delivery. PMID:25894615

  11. Time trial: A prospective comparative study of the time-resource burden for three-dimensional conformal radiotherapy and intensity-modulated radiotherapy in head and neck cancers

    Directory of Open Access Journals (Sweden)

    Murthy Vedang

    2009-01-01

    Full Text Available Introduction: An ongoing institutional randomized clinical trial comparing three-dimensional conformal radiotherapy (3D CRT and intensity-modulated radiotherapy (IMRT provided us an opportunity to document and compare the time-manpower burden with these high-precision techniques in head and neck cancers. Materials and Methods: A cohort of 20 consecutive patients in the ongoing trial was studied. The radiotherapy planning and delivery process was divided into well-defined steps and allocated human resource based on prevalent departmental practice. Person-hours for each step were calculated. Results: Twelve patients underwent IMRT and eight patients had 3D CRT. The prerandomization steps (upto and including approval of contours were common between the two arms, and expectedly, the time taken to complete each step was similar. The planning step was carried out postrandomization and the median times were similar for 3D CRT (312 min, 5.2 person-hours and IMRT (325.6 min, 5.4 person-hours. The median treatment delivery time taken per fraction varied between the two arms, with 3D CRT taking 15.2 min (0.6 person-hours, while IMRT taking 27.8 min (0.9 person-hours (P< 0.001. The total treatment time was also significantly longer in the IMRT arm (median 27.7 versus 17.8 person-hours, P< 0.001. The entire process of IMRT took 48.5 person-hours while 3D CRT took a median of 37.3 person-hours. The monitor units delivered per fraction and the actual "beam-on" time was also statistically longer with IMRT. Conclusions: IMRT required more person-hours than 3D CRT, the main difference being in the time taken to deliver the step-and-shoot IMRT and the patient-specific quality assurance associated with IMRT.

  12. SU-E-T-809: Volumetric Modulated Arc Radiotherapy Vs. Intensity-Modulated Radiotherapy for Locally Advanced Laryngeal Carcinoma: A Dosimetric Study

    Energy Technology Data Exchange (ETDEWEB)

    Lu, J-Y; Huang, B-T; Zhang, W-Z; Yan, L-J [Cancer Hospital of Shantou University Medical College, Shantou, Guangdong (China)

    2015-06-15

    Purpose: To compare volumetric modulated arc radiotherapy (VMAT) technique with fixed-gantry intensity-modulated radiotherapy (IMRT) technique for locally advanced laryngeal carcinoma. Methods: CT datasets of eleven patients were included. Dual-arc VMAT and 7-field IMRT plans, which were created based on the Eclipse treatment planning system, were compared in terms of dose-volume parameters, conformity index (CI) and homogeneity index (HI) of planning target volume (PTV), as well as organ-at-risk (OAR) sparing, planning time, monitor units (MUs) and delivery time. Results: Compared with the IMRT plans, the VMAT plans provided lower D2% and better CI/HI for the high-risk PTV (PTV1), and provided better CI and comparable HI for the low-risk PTV (PTV2). Concerning the OAR sparing, the VMAT plans demonstrated significantly lower Dmax of the spinal cord (planning OAR volume, PRV) and brainstem (PRV), as well as lower Dmean and V30Gy of the right parotid. No significant differences were observed between the two plans concerning the doses delivered to the thyroid, carotid, oral cavity and left parotid. Moreover, the VMAT planning (147 ± 18 min) consumed 213% more time than the IMRT planning (48 ± 10 min). The MUs of the VMAT plans (556 ± 52) were 64% less than those of the IMRT plans (1684 ± 409), and the average delivery time (2.1 ± 0.1 min) was 66% less than that of the IMRT plans (6.3 ± 0.7 min). Conclusion: Compared with the IMRT technique, the VMAT technique can achieve superior target dose distribution and better sparing of the spinal cord, brainstem and right parotid, with less MUs and less delivery time. It is recommended for the radiotherapy of locally advanced laryngeal carcinoma.

  13. Superiority of helical tomotherapy on liver sparing and dose escalation in hepatocellular carcinoma: a comparison study of three-dimensional conformal radiotherapy and intensity-modulated radiotherapy

    Science.gov (United States)

    Zhao, Qianqian; Wang, Renben; Zhu, Jian; Jin, Linzhi; Zhu, Kunli; Xu, Xiaoqing; Feng, Rui; Jiang, Shumei; Qi, Zhonghua; Yin, Yong

    2016-01-01

    Background and purpose To compare the difference of liver sparing and dose escalation between three-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), and helical tomotherapy (HT) for hepatocellular carcinoma. Patients and methods Sixteen unresectable HCC patients were enrolled in this study. First, some evaluation factors of 3DCRT, IMRT, and HT plans were calculated with prescription dose at 50 Gy/25 fractions. Then, the doses were increased using HT or IMRT independently until either the plans reached 70 Gy or any normal tissue reached the dose limit according to quantitative analysis of normal tissue effects in the clinic criteria. Results The conformal index of 3DCRT was lower than that of IMRT (PV50% (fraction of normal liver treated to at least 50% of the isocenter dose) of the normal liver, there was a significant difference: 3DCRT > IMRT > HT (P<0.001). HT had a lower Dmean (mean dose) and V20 (Vn, the percentage of organ volume receiving ≥n Gy) of liver compared with 3DCRT (P=0.005 and P=0.005, respectively) or IMRT (P=0.508 and P=0.007, respectively). Dmean of nontarget normal liver and V30 of liver were higher for 3DCRT than IMRT (P=0.005 and P=0.005, respectively) or HT (P=0.005 and P=0.005, respectively). Seven patients in IMRT (43.75%) and nine patients in HT (56.25%) reached the isodose 70 Gy, meeting the dose limit of the organs at risk. Conclusion HT may provide significantly better liver sparing and allow more patients to achieve higher prescription dose in HCC radiotherapy. PMID:27445485

  14. RapidArc radiotherapy planning for prostate cancer: Single-arc and double-arc techniques vs. intensity-modulated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sze, Henry C.K., E-mail: szeck@ha.org.hk [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong (Hong Kong); Lee, Michael C.H.; Hung, Wai-Man; Yau, Tsz-Kok; Lee, Anne W.M. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong (Hong Kong)

    2012-04-01

    RapidArc is a novel technique using arc radiotherapy aiming to achieve intensity-modulated radiotherapy (IMRT)-quality radiotherapy plans with shorter treatment time. This study compared the dosimetric quality and treatment efficiency of single-arc (SA) vs. double-arc (DA) and IMRT in the treatment of prostate cancer. Fourteen patients were included in the analysis. The planning target volume (PTV), which contained the prostate gland and proximal seminal vesicles, received 76 Gy in 38 fractions. Seven-field IMRT, SA, and DA plans were generated for each patient. Dosimetric quality in terms of the minimum PTV dose, PTV hotspot, inhomogeneity, and conformity index; and sparing of rectum, bladder, and femoral heads as measured by V70, V-40, and V20 (% of volume receiving >70 Gy, 40 Gy, and 20 Gy, respectively), treatment efficiency as assessed by monitor units (MU) and treatment time were compared. All plan objectives were met satisfactorily by all techniques. DA achieved the best dosimetric quality with the highest minimum PTV dose, lowest hotspot, and the best homogeneity and conformity. It was also more efficient than IMRT. SA achieved the highest treatment efficiency with the lowest MU and shortest treatment time. The mean treatment time for a 2-Gy fraction was 4.80 min, 2.78 min, and 1.30 min for IMRT, DA, and SA, respectively. However, SA also resulted in the highest rectal dose. DA could improve target volume coverage and reduce treatment time and MU while maintaining equivalent normal tissue sparing when compared with IMRT. SA achieved the greatest treatment efficiency but with the highest rectal dose, which was nonetheless within tolerable limits. For busy units with high patient throughput, SA could be an acceptable option.

  15. Simultaneous integrated boost intensity-modulated radiotherapy in esophageal carcinoma. Early results of a phase II study

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    Yu, Wei-Wei [Fudan University, Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Shanghai (China); Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Department of Radiation Oncology, Shanghai (China); Zhu, Zheng-Fei; Zhao, Kuai-Le; Mao, Jing-Fang; Wu, Kai-Liang; Yang, Huan-Jun; Fan, Min; Zhao, Sen [Fudan University, Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Shanghai (China); Fu, Xiao-Long [Fudan University Cancer Hospital, Department of Radiation Oncology, Shanghai (China); Fudan University, Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Shanghai (China); Welsh, James [The University of Texas MD Anderson Cancer Center, Departments of Radiation Oncology, Houston, Texas (United States)

    2014-11-15

    The safety and efficacy of using simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) for patients with esophageal squamous cell carcinoma were evaluated in a single-institution phase II setting. Between June 2007 and October 2009, 45 patients underwent concurrent chemoradiotherapy (n = 27) or radiotherapy alone (n = 18). Two planning target volumes (PTV) were defined for the SIB: PTV{sub C} and PTV{sub G}, with prescribed doses of 50.4 Gy to the PTV{sub C} (1.8 Gy/fraction) and 63 Gy to the PTV{sub G} (2.25 Gy/fraction), both given in 28 fractions. At a median follow-up interval of 20.3 months, the 3-year overall survival (OS) and progression-free survival (PFS) rates were 42.2 and 40.7 %, respectively. The median overall survival time was 21 months; locoregional control rates were 83.3 % at 1 year and 67.5 % at 3 years. According to CTCAE (version 3.0) criteria, none of the patients developed grade 4-5 toxicity. The most common grade 2 and 3 radiation-related toxicity was radiation esophagitis, occurring in 64 % of all patients (but only 13 % as grade 3). No patient developed grade > 2 pulmonary complications. SIB-IMRT is a feasible therapeutic approach for esophageal carcinoma patients and provides encouraging locoregional control with a low toxicity profile. Further investigations should focus on dose escalation and optimization of the combination with systemic therapies. (orig.) [German] Die Wirksamkeit und Effektivitaet einer intensitaetsmodulierten Radiotherapie mit einem simultan integrierten Boost (SIB-IMRT) fuer Patienten mit Oesophaguskarzinom wurde in einer Single-Institution-Phase-II-Studie bewertet. Zwischen Juni 2007 und Oktober 2009 wurden 45 Patienten mit einer simultanen Radiochemotherapie (n = 27) oder einer alleinigen Strahlentherapie (n = 18) behandelt. Zwei Planungszielvolumen (PTV) wurden fuer die SIB definiert: PTV{sub C} und PTV{sub G}, mit vorgeschriebenen Dosen von 50,4 Gy fuer PTV{sub C} (1,8 Gy/Fraktion) und 63 Gy

  16. Dosimetric Comparison of Combined Intensity-Modulated Radiotherapy (IMRT) and Proton Therapy Versus IMRT Alone for Pelvic and Para-Aortic Radiotherapy in Gynecologic Malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Berman Milby, Abigail [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Both, Stefan, E-mail: both@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Ingram, Mark; Lin, Lilie L. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States)

    2012-03-01

    Purpose: To perform a dosimetric comparison of intensity-modulated radiotherapy (IMRT), passive scattering proton therapy (PSPT), and intensity-modulated proton therapy (IMPT) to the para-aortic (PA) nodal region in women with locally advanced gynecologic malignancies. Methods and Materials: The CT treatment planning scans of 10 consecutive patients treated with IMRT to the pelvis and PA nodes were identified. The clinical target volume was defined by the primary tumor for patients with cervical cancer and by the vagina and paravaginal tissues for patients with endometrial cancer, in addition to the regional lymph nodes. The IMRT, PSPT, and IMPT plans were generated using the Eclipse Treatment Planning System and were analyzed for various dosimetric endpoints. Two groups of treatment plans including proton radiotherapy were created: IMRT to pelvic nodes with PSPT to PA nodes (PSPT/IMRT), and IMRT to pelvic nodes with IMPT to PA nodes (IMPT/IMRT). The IMRT and proton RT plans were optimized to deliver 50.4 Gy or Gy (relative biologic effectiveness [RBE)), respectively. Dose-volume histograms were analyzed for all of the organs at risk. The paired t test was used for all statistical comparison. Results: The small-bowel V{sub 20}, V{sub 30}, V{sub 35}, andV{sub 40} were reduced in PSPT/IMRT by 11%, 18%, 27%, and 43%, respectively (p < 0.01). Treatment with IMPT/IMRT demonstrated a 32% decrease in the small-bowel V{sub 20}. Treatment with PSPT/IMRT showed statistically significant reductions in the body V{sub 5-20}; IMPT/IMRT showed reductions in the body V{sub 5-15}. The dose received by half of both kidneys was reduced by PSPT/IMRT and by IMPT/IMRT. All plans maintained excellent coverage of the planning target volume. Conclusions: Compared with IMRT alone, PSPT/IMRT and IMPT/IMRT had a statistically significant decrease in dose to the small and large bowel and kidneys, while maintaining excellent planning target volume coverage. Further studies should be done to

  17. Intensity modulated radiotherapy (IMRT) for patients of the Brazilian unified health system (SUS): an analysis of 508 treatments two years after the technique implementation

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    Oliveira, Harley Francisco de; Trevisan, Felipe Amstalden; Bighetti, Viviane Marques; Guimaraes, Flavio da Silva; Amaral, Leonardo Lira; Barbi, Gustavo Lazaro; Borges, Leandro Federiche; Peria, Fernanda Maris, E-mail: harley@fmrp.usp.br [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    2014-11-15

    Objective: the offering of high-technology radiotherapy to the population assisted by the Brazilian unified health system (SUS) is limited since it is not included in the system’s list of procedures and, many times, because of the insufficient installed capacity and lack of specialized human resources. Thus the access to intensity-modulated radiotherapy (IMRT) is restricted to few centers in Brazil. The present study is aimed at presenting the characteristics of the first 508 cases treated with IMRT during the first years after the technique implementation in a university hospital. Materials and methods: the first consecutive 508 cases of IMRT treatment completed in the period from May/2011 to September/2013 were reviewed. Static multi leaf was the technique employed. Results: amongst 4,233 treated patients, 12.5% were submitted to IMRT. Main indications for the treatment included cancers located in the skull, head and neck and prostate. Intensity modulated radiotherapy was utilized in about 30% of cranial and 50% of prostate treatments. Treatment toxicity was observed in 4% of the patients. Conclusion: because of restricted access to radiotherapy in addition to lack of coverage for the procedure, IMRT indications for SUS patients should be based on institutional clinical protocols, with special attention to the reduction of toxicity. (author)

  18. Prognostic value and staging classification of retropharyngeal lymph node metastasis in nasopharyngeal carcinoma patients treated with intensity-modulated radiotherapy.

    Directory of Open Access Journals (Sweden)

    Ling-Long Tang

    Full Text Available BACKGROUND: The development of intensity-modulated radiotherapy (IMRT has revolutionized the management of nasopharyngeal carcinoma (NPC. The purpose of this study was to evaluate the prognostic value and classification of TNM stage system for retropharyngeal lymph node (RLN metastasis in NPC in the IMRT era. MATERIAL AND METHODS: We retrospectively reviewed data from 749 patients with biopsy-proven, non-metastatic NPC. All patients received IMRT as the primary treatment. Chemotherapy was administered to 86.2% (424/492 of the patients with stage III or IV disease. RESULTS: The incidence of RLN metastasis was 64.2% (481/749. Significant differences were observed in the 5-year disease-free survival (DFS; 70.6% vs. 85.4%, P<0.001 and distant metastasis-free survival (DMFS; 79.2% vs. 90.1%, P<0.001 rates of patients with and without RLN metastasis. In multivariate analysis, RLN metastasis was an independent prognostic factor for disease failure and distant failure (P = 0.005 and P = 0.026, respectively, but not for locoregional recurrence. Necrotic RLN metastases have a negative effect on disease failure, distant failure and locoregional recurrence in NPC with RLN metastasis (P = 0.003, P = 0.018 and P = 0.005, respectively. Survival curves demonstrated a significant difference in DFS between patients with N0 disease and N1 disease with only RLN metastasis (P = 0.020, and marginally statistically significant differences in DMFS and DFS between N1 disease with only RLN metastasis and other N1 disease (P = 0.058 and P = 0.091, respectively. In N1 disease, no significant differences in DFS were observed between unilateral and bilateral RLN metastasis (P = 0.994. CONCLUSIONS: In the IMRT era, RLN metastasis remains an independent prognostic factor for DFS and DMFS in NPC. It is still reasonable for RLN metastasis to be classified in the N1 disease, regardless of laterality. However, there is a need to investigate the feasibility of classifying RLN

  19. Long-Term Outcomes of Early-Stage Nasopharyngeal Carcinoma Patients Treated With Intensity-Modulated Radiotherapy Alone

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    Su Shengfa [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Department of Radiation Oncology, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Department of Oncology, GuiYang Medical College Hospital, Guiyang, Guizhou (China); Han Fei; Zhao Chong; Chen Chunyan; Xiao Weiwei; Li Jiaxin [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Department of Radiation Oncology, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Lu Taixiang, E-mail: ssf2010@sina.cn [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Department of Radiation Oncology, Cancer Center, Sun Yat-Sen University, Guangzhou (China)

    2012-01-01

    Purpose: Reports of intensity-modulated radiotherapy (IMRT) for early-stage nasopharyngeal carcinoma (NPC) have been limited. The present study evaluated the long-term survival outcomes and toxicity of early-stage NPC patients treated with IMRT alone. Methods and Materials: Between February 2001 and January 2008, 198 early-stage (T1-T2bN0-N1M0) NPC patients had undergone IMRT alone. The data from these patients were retrospectively analyzed. The patients were treated to 68 Gy at 2.27 Gy/fraction prescribed to the planning target volume of the primary nasopharygeal gross tumor volume. The Radiation Therapy Oncology Group scoring system was used to assess the toxicity. Results: At a median follow-up of 50.9 months (range, 12-104), the 5-year estimated disease-specific survival, local recurrence-free survival, and distant metastasis-free survival rate was 97.3%, 97.7%, and 97.8%, respectively. The 5-year local recurrence-free survival rate was 100% for those with Stage T1 and T2a and 94.2% for those with Stage T2b lesions (p = 0.252). The 5-year distant metastasis-free survival rate for Stage T1N0, T2N0, T1N1, and T2N1 patients was 100%, 98.8%, 100%, and 93.8%, respectively (p = .073). All local recurrence occurred in patients with T2b lesions. Five patients developed distant metastasis. Of these 5 patients, 4 had had Stage T2bN1 disease and 1 had had Stage T2bN0 disease with retropharyngeal lymph node involvement. The most common acute toxicities were mainly Grade 1 or 2. At 24 months after IMRT, no Grade 3 or 4 xerostomia had developed, and 62 (96.9%) of 64 evaluated patients were free of trismus; only 2 patients (3.1%) had Grade 1 trismus. Radiation encephalopathy and cranial nerve injury were not observed. Conclusions: IMRT alone for Stage T1N0, T2N0, T1N1, and T2N1 yielded satisfactory survival outcomes with acceptable toxicity, and no differences were found in survival outcomes among these four subgroups. Patients with Stage T2b lesions might have relatively

  20. Clinical outcomes for gastric cancer following adjuvant chemoradiation utilizing intensity modulated versus three-dimensional conformal radiotherapy.

    Directory of Open Access Journals (Sweden)

    Gene-Fu F Liu

    Full Text Available PURPOSE/OBJECTIVES: To determine if intensity modulated radiation therapy (IMRT in the post-operative setting for gastric cancer was associated with reduced toxicity compared to 3D conformal radiation therapy (3DCRT. MATERIALS/METHODS: This retrospective study includes 24 patients with stage IB-IIIB gastric cancer consecutively treated from 2001-2010. All underwent surgery followed by adjuvant chemoradiation. Concurrent chemotherapy consisted of 5-FU/leucovorin (n = 21, epirubicin/cisplatin/5FU (n = 1, or none (n = 2. IMRT was utilized in 12 patients and 3DCRT in 12 patients. For both groups, the target volume included the tumor bed, anastomosis, gastric stump, and regional lymphatics. RESULTS: Median follow-up for the entire cohort was 19 months (range 0.4-8.5 years, and 49 months (0.5-8.5 years in surviving patients. The 3DCRT group received a median dose of 45 Gy, and the IMRT group received a median dose of 50.4 Gy (p = 0.0004. For the entire cohort, 3-year overall survival (OS was 40% and 3-year disease free survival (DFS was 41%. OS and DFS did not differ significantly between the groups. Acute toxicity was similar. Between 3DCRT and IMRT groups, during radiotherapy, median weight lost (3.2 vs. 3.3 kg, respectively; p = 0.47 and median percent weight loss were similar (5.0% vs. 4.3%, respectively; p = 0.43. Acute grade 2 toxicity was experienced by 8 patients receiving 3DCRT and 11 receiving IMRT (p = 0.32; acute grade 3 toxicity occurred in 1 patient receiving 3DCRT and none receiving IMRT (p = 1.0. No patients in either cohort experienced late grade 3 toxicity, including renal or gastrointestinal toxicity. At last follow up, the median increase in creatinine was 0.1 mg/dL in the IMRT group and 0.1 mg/dL in the 3DCRT group (p = 0.78. CONCLUSION: This study demonstrates that adjuvant chemoradiation for gastric cancer with IMRT to 50.4 Gy was well-tolerated and compared similarly in toxicity with 3DCRT to

  1. 3D-conformal-intensity modulated radiotherapy with compensators for head and neck cancer: clinical results of normal tissue sparing

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    Koscielny Sven

    2006-06-01

    Full Text Available Abstract Background To investigate the potential of parotic gland sparing of intensity modulated radiotherapy (3D-c-IMRT performed with metallic compensators for head and neck cancer in a clinical series by analysis of dose distributions and clinical measures. Materials and methods 39 patients with squamous cell cancer of the head and neck irradiated using 3D-c-IMRT were evaluable for dose distribution within PTVs and at one parotid gland and 38 patients for toxicity analysis. 10 patients were treated primarily, 29 postoperatively, 19 received concomittant cis-platin based chemotherapy, 20 3D-c-IMRT alone. Initially the dose distribution was calculated with Helax ® and photon fluence was modulated using metallic compensators made of tin-granulate (n = 22. Later the dose distribution was calculated with KonRad ® and fluence was modified by MCP 96 alloy compensators (n = 17. Gross tumor/tumor bed (PTV 1 was irradiated up to 60–70 Gy, [5 fractions/week, single fraction dose: 2.0–2.2 (simultaneously integrated boost], adjuvantly irradiated bilateral cervical lymph nodes (PTV 2 with 48–54 Gy [single dose: 1.5–1.8]. Toxicity was scored according the RTOG scale and patient-reported xerostomia questionnaire (XQ. Results Mean of the median doses at the parotid glands to be spared was 25.9 (16.3–46.8 Gy, for tin graulate 26 Gy, for MCP alloy 24.2 Gy. Tin-granulate compensators resulted in a median parotid dose above 26 Gy in 10/22, MCP 96 alloy in 0/17 patients. Following acute toxicities were seen (°0–2/3: xerostomia: 87%/13%, dysphagia: 84%/16%, mucositis: 89%/11%, dermatitis: 100%/0%. No grade 4 reaction was encountered. During therapy the XQ forms showed °0–2/3: 88%/12%. 6 months postRT chronic xerostomia °0–2/3 was observed in 85%/15% of patients, none with °4 xerostomia. Conclusion 3D-c-IMRT using metallic compensators along with inverse calculation algorithm achieves sufficient parotid gland sparing in virtually all advanced

  2. SU-E-T-379: Concave Approximations of Target Volume Dose Metrics for Intensity- Modulated Radiotherapy Treatment Planning

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    Xie, Y; Chen, Y; Wickerhauser, M [Washington University in St. Louis, St. Louis, MO (United States); Deasy, J [Memorial Sloan Kettering Cancer Center, NY, NY (United States)

    2014-06-01

    Purpose: The widely used treatment plan metric Dx (mimimum dose to the hottest x% by volume of the target volume) is simple to interpret and use, but is computationally poorly behaved (non-convex), this impedes its use in computationally efficient intensity-modulated radiotherapy (IMRT) treatment planning algorithms. We therefore searched for surrogate metrics that are concave, computationally efficient, and accurately correlated to Dx values in IMRT treatment plans. Methods: To find concave surrogates of D95—and more generally, Dx values with variable x values—we tested equations containing one or two generalized equivalent uniform dose (gEUD) functions. Fits were obtained by varying gEUD ‘a’ parameter values, as well as the linear equation coefficients. Fitting was performed using a dataset of dose-volume histograms from 498 de-identified head and neck IMRT treatment plans. Fit characteristics were tested using a crossvalidation process. Reported root-mean-square error values were averaged over the cross-validation shuffles. Results: As expected, the two-gEUD formula provided a superior fit, compared to the single-gEUD formula. The best approximation uses two gEUD terms: 16.25 x gEUD[a=0.45] – 15.30 x gEUD[a=1.75] – 0.69. The average root-mean-square error on repeated (70/30) cross validation was 0.94 Gy. In addition, a formula was found that reasonably approximates Dx for x between 80% and 96%. Conclusion: A simple concave function using two gEUD terms was found that correlates well with PTV D95s for these head and neck treatment plans. More generally, a formula was found that represents well the Dx for x values from 80% to 96%, thus providing a computationally efficient formula for use in treatment planning optimization. The formula may need to be adjusted for other institutions with different treatment planning protocols. We conclude that the strategy of replacing Dx values with gEUD-based formulas is promising.

  3. Dosimetric study of volumetric arc modulation with RapidArc and intensity-modulated radiotherapy in patients with cervical cancer and comparison with 3-dimensional conformal technique for definitive radiotherapy in patients with cervical cancer

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    Guy, Jean-Baptiste [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Falk, Alexander T. [Department of Radiation Oncology, Centre Antoine Lacassagne, Nice (France); Auberdiac, Pierre [Department of Radiation Oncology, Clinique Claude Bernard, Albi (France); Cartier, Lysian; Vallard, Alexis [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Ollier, Edouard [Department of Pharmacology-Toxicology, Centre Hospitalier Universitaire de Saint-Etienne, Saint-Priest en Jarez (France); Trone, Jane-Chloé; Khodri, Moustapha [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Chargari, Cyrus [Department of Radiation Oncology, Hôpital d’instruction de Armées du Val-de-Grâce, Paris (France); Magné, Nicolas, E-mail: nicolas.magne@icloire.fr [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France)

    2016-04-01

    Introduction: For patients with cervical cancer, intensity-modulated radiation therapy (IMRT) improves target coverage and allows dose escalation while reducing the radiation dose to organs at risk (OARs). In this study, we compared dosimetric parameters among 3-dimensional conformal radiotherapy (3D-CRT), “step-and-shoot” IMRT, and volumetric intensity-modulated arc radiotherapy (VMAT) in a series of patients with cervical cancer receiving definitive radiotherapy. Computed tomography (CT) scans of 10 patients with histologically proven cervical cancer treated with definitive radiation therapy (RT) from December 2008 to March 2010 at our department were selected for this study. The gross tumor volume (GTV) and clinical target volume (CTV) were delineated following the guidelines of the Gyn IMRT consortium that included cervix, uterus, parametrial tissues, and the pelvic nodes including presacral. The median age was 57 years (range: 30 to 85 years). All 10 patients had squamous cell carcinoma with Federation of Gynecology and Obstetrics (FIGO) stage IB-IIIB. All patients were treated by VMAT. OAR doses were significantly reduced for plans with intensity-modulated technique compared with 3D-CRT except for the dose to the vagina. Between the 2 intensity-modulated techniques, significant difference was observed for the mean dose to the small intestine, to the benefit of VMAT (p < 0.001). There was no improvement in terms of OARs sparing for VMAT although there was a tendency for a slightly decreased average dose to the rectum: − 0.65 Gy but not significant (p = 0.07). The intensity modulation techniques have many advantages in terms of quality indexes, and particularly OAR sparing, compared with 3D-CRT. Following the ongoing technologic developments in modern radiotherapy, it is essential to evaluate the intensity-modulated techniques on prospective studies of a larger scale.

  4. Superiority of helical tomotherapy on liver sparing and dose escalation in hepatocellular carcinoma: a comparison study of three-dimensional conformal radiotherapy and intensity-modulated radiotherapy

    Directory of Open Access Journals (Sweden)

    Zhao QQ

    2016-06-01

    Full Text Available Qianqian Zhao,1,2 Renben Wang,2 Jian Zhu,2 Linzhi Jin,1,2 Kunli Zhu,2 Xiaoqing Xu,2 Rui Feng,2 Shumei Jiang,2 Zhonghua Qi,1,2 Yong Yin2 1School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, 2Department of Radiation Oncology, Shandong Cancer Hospital affiliated to Shandong University, Jinan, People’s Republic of China Background and purpose: To compare the difference of liver sparing and dose escalation between three-dimensional conformal radiotherapy (3DCRT, intensity-modulated radiotherapy (IMRT, and helical tomotherapy (HT for hepatocellular carcinoma.Patients and methods: Sixteen unresectable HCC patients were enrolled in this study. First, some evaluation factors of 3DCRT, IMRT, and HT plans were calculated with prescription dose at 50 Gy/25 fractions. Then, the doses were increased using HT or IMRT independently until either the plans reached 70 Gy or any normal tissue reached the dose limit according to quantitative analysis of normal tissue effects in the clinic criteria.Results: The conformal index of 3DCRT was lower than that of IMRT (P<0.001 or HT (P<0.001, and the homogeneity index of 3DCRT was higher than that of IMRT (P<0.001 or HT (P<0.001. HT took the longest treatment time (P<0.001. For V50% (fraction of normal liver treated to at least 50% of the isocenter dose of the normal liver, there was a significant difference: 3DCRT > IMRT > HT (P<0.001. HT had a lower Dmean (mean dose and V20 (Vn, the percentage of organ volume receiving ≥n Gy of liver compared with 3DCRT (P=0.005 and P=0.005, respectively or IMRT (P=0.508 and P=0.007, respectively. Dmean of nontarget normal liver and V30 of liver were higher for 3DCRT than IMRT (P=0.005 and P=0.005, respectively or HT (P=0.005 and P=0.005, respectively. Seven patients in IMRT (43.75% and nine patients in HT (56.25% reached the isodose 70 Gy, meeting the dose limit of the organs at risk.Conclusion: HT may provide significantly better

  5. Functional Image-Guided Radiotherapy Planning in Respiratory-Gated Intensity-Modulated Radiotherapy for Lung Cancer Patients With Chronic Obstructive Pulmonary Disease

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    Kimura, Tomoki, E-mail: tkkimura@hiroshima-u.ac.jp [Department of Radiation Oncology, Hiroshima University, Graduate School of Biomedical Sciences, Hiroshima City (Japan); Nishibuchi, Ikuno; Murakami, Yuji; Kenjo, Masahiro; Kaneyasu, Yuko; Nagata, Yasushi [Department of Radiation Oncology, Hiroshima University, Graduate School of Biomedical Sciences, Hiroshima City (Japan)

    2012-03-15

    Purpose: To investigate the incorporation of functional lung image-derived low attenuation area (LAA) based on four-dimensional computed tomography (4D-CT) into respiratory-gated intensity-modulated radiotherapy (IMRT) or volumetric modulated arc therapy (VMAT) in treatment planning for lung cancer patients with chronic obstructive pulmonary disease (COPD). Methods and Materials: Eight lung cancer patients with COPD were the subjects of this study. LAA was generated from 4D-CT data sets according to CT values of less than than -860 Hounsfield units (HU) as a threshold. The functional lung image was defined as the area where LAA was excluded from the image of the total lung. Two respiratory-gated radiotherapy plans (70 Gy/35 fractions) were designed and compared in each patient as follows: Plan A was an anatomical IMRT or VMAT plan based on the total lung; Plan F was a functional IMRT or VMAT plan based on the functional lung. Dosimetric parameters (percentage of total lung volume irradiated with {>=}20 Gy [V20], and mean dose of total lung [MLD]) of the two plans were compared. Results: V20 was lower in Plan F than in Plan A (mean 1.5%, p = 0.025 in IMRT, mean 1.6%, p = 0.044 in VMAT) achieved by a reduction in MLD (mean 0.23 Gy, p = 0.083 in IMRT, mean 0.5 Gy, p = 0.042 in VMAT). No differences were noted in target volume coverage and organ-at-risk doses. Conclusions: Functional IGRT planning based on LAA in respiratory-guided IMRT or VMAT appears to be effective in preserving a functional lung in lung cancer patients with COPD.

  6. SU-E-T-808: Volumetric Modulated Arc Radiotherapy Vs. Intensity-Modulated Radiotherapy for Early-Stage Nasopharyngeal Carcinoma: A Dosimetric Study

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

    2015-06-15

    Purpose: To compare volumetric modulated arc radiotherapy (VMAT) technique with fixed-gantry intensity-modulated radiotherapy (IMRT) technique for early-stage nasopharyngeal carcinoma. Methods: CT datasets of ten patients with early-stage nasopharyngeal carcinoma were included. Dual-arc VMAT and nine-field IMRT plans were generated for each case, and were then compared in terms of planning-target-volume (PTV) coverage, conformity index (CI) and homogeneity index (HI), as well as organ-at-risk (OAR) sparing, planning time, monitor units (MUs) and delivery time. Results: Compared with the IMRT plans, the VMAT plans provided comparable HI and CI of PTVnx (PTV of primary tumor of nasopharynx), superior CI and inferior HI of PTVnd (PTV of lymph nodes), as well as superior CI and comparable HI of PTV60 (high-risk PTV). The VMAT plans provided better sparing of the spinal cord, oral cavity and normal tissue, but inferior sparing of the brainstem planning OAR volume (PRV), larynx and parotids, as well as comparable sparing of the spinal cord PRV, brainstem, lenses, optic nerves, optic chiasm. Moreover, the average planning time (181.6 ± 36.0 min) for the VMAT plans was 171% more than that of the IMRT plans (68.1 ± 7.6 min). The MUs of the VMAT plans (609 ± 43) were 70% lower than those of the IMRT plans (2071 ± 262), while the average delivery time (2.2 ± 0.1 min) was 66% less than that of the IMRT plans (6.6 ± 0.4 min). Conclusion: Compared with the IMRT technique, the VMAT technique can achieve similar or slightly superior target dose distribution, with no significant advantages on OAR sparing, and it can achieve significant reductions of MUs and delivery time.

  7. A dosimetric analysis of volumetric-modulated arc radiotherapy with jaw width restriction vs 7 field intensity-modulated radiotherapy for definitive treatment of cervical cancer.

    Science.gov (United States)

    Huang, B; Fang, Z; Huang, Y; Lin, P; Chen, Z

    2014-07-01

    Radiation therapy treatment planning was performed to compare the dosimetric difference between volumetric-modulated arc radiotherapy (RapidArc™ v. 10; Varian® Medical Systems, Palo Alto, CA) and 7-field intensity-modulated radiotherapy (7f-IMRT) in the definitive treatment of cervical cancer. 13 patients with cervical cancer were enrolled in this study. Planning target volume (PTV) 50 and PTV60 were prescribed at a dose of 50 and 60 Gy in 28 fractions, respectively. The dose to the PTV60 was delivered as a simultaneous integrated boost to the pelvic lymph nodes. Owing to the mechanical limitation of the multileaf collimator in which the maximum displacement was limited to 15 cm, two types of RapidArc with different jaw width restrictions (15 and 20-23 cm) were investigated to evaluate their dosimetric differences. The RapidArc plan type with dosimetric superiority was then compared against the 7f-IMRT on the target coverage, sparing of the organs at risk (OARs), monitor units, treatment time and delivery accuracy to determine whether RapidArc is beneficial for the treatment of cervical cancer. The 15-cm jaw width restriction had better performance compared with the restrictions that were longer than 15 cm in the sparing of the OARs. The 15-cm RapidArc spared the OARs, that is, the bladder, rectum, small intestine, femoral heads and bones, and improved treatment efficiency compared with 7f-IMRT. Both techniques delivered a high quality-assurance passing rate (>90%) according to the Γ3mm,3% criterion. RapidArc with a 15-cm jaw width restriction spares the OARs and improves treatment efficiency in cervical cancer compared with 7f-IMRT. This study describes the dosimetric superiority of RapidArc with a 15-cm jaw width restriction and explores the feasibility of using RapidArc for the definitive treatment of cervical cancer.

  8. SU-E-T-302: Dosimetric Comparison Between Volumetric Modulated Arc Radiotherapy and Intensity-Modulated Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma

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

    2015-06-15

    Purpose: To compare volumetric modulated arc radiotherapy (VMAT) technique with fixed-gantry intensity-modulated radiotherapy (IMRT) technique for locally recurrent nasopharyngeal carcinoma. Methods: CT datasets of eleven nasopharyngeal-carcinoma patients were included. Dual-arc VMAT and seven-field IMRT plans were created for each case, and were then compared in terms of conformity index (CI), homogeneity index (HI) of the planning target volume (PTV), organ-at-risk (OAR) sparing, monitor unit (MU) and delivery time. Results: The D98% (near-minimal dose) of PTV in the VMAT plans was slightly lower than that of the IMRT plans (P < 0.05), while the CI was higher than that of the IMRT plans (P < 0.05). No significant difference was found in the HI between the two plans (P > 0.05). Compared with the IMRT plans, the VMAT plans demonstrated lower Dmean (mean dose) of the bilateral temporal lobes and the whole surrounding normal tissue (P < 0.05), but slightly higher Dmean of brainstem (P < 0.05). In terms of the other OARs, no significant differences were found (P > 0.05). The MUs of the VMAT plans (672 ± 112) was significantly lower than that of the IMRT plans (917 ± 206), by 25 ± 13% (P < 0.05). The average delivery time of the VMAT plans (2.3 ± 0.1 min) was less than that of the IMRT plans (5.1 ± 0.4 min), by 54 ± 3%. Conclusion: For locally recurrent nasopharyngeal carcinoma, the VMAT technique could achieve equivalent or superior dose distribution of the target and better protect the bilateral temporal lobes, compared with the IMRT technique. Moreover, it could reduce the MU and delivery time effectively.

  9. Intensity-modulated radiotherapy for laryngeal and hypopharyngeal cancer. Minimization of late dysphagia without jeopardizing tumor control

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    Modesto, Anouchka; Laprie, Anne; Graff, Pierre; Rives, Michel [Institut Universitaire du Cancer, Department of Radiation Oncology, Institut Claudius Regaud, Toulouse (France); Vieillevigne, Laure [Institut Universitaire du Cancer, Department of Medical Physics, Toulouse (France); Sarini, Jerome; Vergez, Sebastien; Farenc, Jean-Claude [Institut Universitaire du Cancer, Department of Head and Neck Surgery, Toulouse (France); Delord, Jean-Pierre [Institut Universitaire du Cancer, Department of Medical Oncology, Toulouse (France); Vigarios, Emmanuelle [Centre Hospitalo Universitaire de Rangueil, Dental Surgery Department, Toulouse (France); Filleron, Thomas [Institut Universitaire du Cancer, Department of Biostatistics, Toulouse (France)

    2014-11-01

    The purpose of this work was to retrospectively determine the value of intensity-modulated radiotherapy (IMRT) in patients with laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC), on outcome and treatment-related toxicity compared to 3-dimensional conformal radiotherapy (3D-CRT). A total of 175 consecutive patients were treated between 2007 and 2012 at our institution with curative intent RT and were included in this study: 90 were treated with 3D-CRT and 85 with IMRT. Oncologic outcomes were estimated using Kaplan-Meier statistics; acute and late toxicities were scored according to the Common Toxicity Criteria for Adverse Events scale v 3.0. Median follow-up was 35 months (range 32-42 months; 95% confidence interval 95 %). Two-year disease-free survival did not vary, regardless of the technique used (69 % for 3D-CRT vs. 72 %; for IMRT, p = 0.16). Variables evaluated as severe late toxicities were all statistically lower with IMRT compared with 3D-CRT: xerostomia (0 vs. 12 %; p < 0.0001), dysphagia (4 vs. 26 %; p < 0.0001), and feeding-tube dependency (1 vs 13 %; p = 0.0044). The rates of overall grade ≥ 3 late toxicities for the IMRT and 3D-CRT groups were 4.1 vs. 41.4 %, respectively (p < 0.0001). IMRT for laryngeal and hypopharyngeal cancer minimizes late dysphagia without jeopardizing tumor control and outcome. (orig.) [German] Das Ziel dieser Studie war es, retrospektiv den Nutzen der intensitaetsmodulierten Strahlentherapie (IMRT) in der Behandlung von Patienten mit Plattenepithelkarzinom von Kehlkopf und Hypopharynx (LHSCC) zu bewerten und mit dem Outcome und den Spaetfolgen der 3-D-konformalen Strahlentherapie (3D-CRT) zu vergleichen. Insgesamt wurden zwischen Januar 2007 und Dezember 2012175 LHSCC-Patienten mit einer RT behandelt und in die Studie aufgenommen: 85 Patienten wurden mit 3D-CRT und 90 Patienten mit IMRT behandelt.Das onkologische Outcome wurde mittels Kaplan-Meier-Statistik ermittelt und Akut- und Spaettoxizitaeten anhand der CTCAE

  10. The benefit of using bladder sub-volume equivalent uniform dose constraints in prostate intensity-modulated radiotherapy planning

    Directory of Open Access Journals (Sweden)

    Zhu J

    2016-12-01

    Full Text Available Jian Zhu,1–3 Antoine Simon,3–5 Pascal Haigron,3–5 Caroline Lafond,4–6 Oscar Acosta,4,5 Huazhong Shu,1,3 Joel Castelli,4–6 Baosheng Li,1–3 Renaud De Crevoisier3–6 1Laboratory of Image Science and Technology, Southeast University, Nanjing, Jiangsu, 2Department of Radiation Oncology, Shandong Cancer Hospital & Institute, Jinan, 3Centre de Recherche en Information Biomédicale Sino-français, Nanjing, People’s Republic of China; 4Institut National de la Sante et de la Recherche Medicale, U1099, 5Laboratory of Signal and Image Processing (LTSI, University of Rennes 1, 6Department of Radiotherapy, Centre Eugène Marquis, Rennes, France Background: To assess the benefits of bladder wall sub-volume equivalent uniform dose (EUD constraints in prostate cancer intensity-modulated radiotherapy (IMRT planning. Methods: Two IMRT plans, with and without EUD constraints on the bladder wall, were generated using beams that deliver 80 Gy to the prostate and 46 Gy to the seminal vesicles and were compared in 53 prostate cancer patients. The bladder wall was defined as the volume between the external manually delineated wall and a contraction of 7 mm apart from it. The bladder wall was then separated into two parts: the internal-bladder wall (bla-in represented by the portion of the bladder wall that intersected with the planning target volume (PTV plus 5 mm extension; the external-bladder wall (bla-ex represented by the remaining part of the bladder wall. In the IMRT plan with EUD constraints, the values of “a” parameter for the EUD models were 10.0 for bla-in and 2.3 for bla-ex. The plans with and without EUD constraints were compared in terms of dose–volume histograms, 5-year bladder and rectum normal tissue complication probability values, as well as tumor control probability (TCP values. Results: The use of bladder sub-volume EUD constraints decreased both the doses to the bladder wall (V70: 22.76% vs 19.65%, Dmean: 39.82 Gy vs 35

  11. Image-guided intensity-modulated radiotherapy of prostate cancer. Analysis of interfractional errors and acute toxicity

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    Rudat, Volker; Nour, A.; Hammoud, M.; Alaradi, A.; Mohammed, A. [Saad Specialist Hospital, Department of Radiation Oncology, Al Khobar (Saudi Arabia)

    2016-02-15

    The aim of the study was to estimate interfractional deviations in patient and prostate position, the impact of the frequency of online verification on the treatment margins, and to assess acute radiation reactions of high-dose external beam image-guided intensity-modulated radiotherapy (IG-IMRT) of localized prostate cancer. IG-IMRT was performed by daily online verification of implanted fiducial prostate markers using a megavoltage electronic portal imaging device (EPID). A total of 1011 image-guided treatment fractions from 23 consecutive unselected prostate cancer patients were analyzed. The median total dose was 79.2 Gy (range 77.4-81.0 Gy). Acute radiation reactions were assessed weekly during radiotherapy using the Common Terminology Criteria for Adverse Events (CTCAE) v.4.03. A relevant combined patient set-up and prostate motion population random error of 4-5 mm was observed. Compared to daily IGRT, image guidance every other day required an expansion of the CTV-PTV (clinical target volume-planning target volume) margin of 8.1, 6.6, and 4.1 mm in the longitudinal, vertical, and lateral directions, thereby, increasing the PTV by approximately 30-40 %. No grade 3 or 4 acute radiation reactions were observed with daily IG-IMRT. A high dose with surprisingly low acute toxicity can be applied with daily IG-IMRT using implanted fiducial prostate markers. Daily image guidance is clearly superior to image guidance every other fraction concerning adequate target coverage with minimal margins. (orig.) [German] Ziel der Studie war es, die interfraktionelle Variabilitaet der Patientenlagerung und Prostataposition, den Einfluss der Bildgebungsfrequenz und die akuten Strahlenreaktionen bei einer hochdosierten bildgesteuerten intensitaetsmodulierten Strahlentherapie (IG-IMRT) des Prostatakarzinoms zu untersuchen. IG-IMRT wurde durch taegliche Verifikation von implantierten roentgendichten Prostatamarkern mittels Megavolt-Bildgebung (''electronic portal imaging

  12. 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.

  13. Comparative analysis of volumetric-modulated arc therapy and intensity-modulated radiotherapy for base of tongue cancer

    Directory of Open Access Journals (Sweden)

    L Nithya

    2014-01-01

    Full Text Available The aim of this study was to compare the various dosimetric parameters of dynamic multileaf collimator (MLC intensity modulated radiation therapy (IMRT plans with volumetric modulated arc therapy (VMAT plans for base of tongue cases. All plans were done in Monaco planning system for Elekta synergy linear accelerator with 80 MLC. IMRT plans were planned with nine stationary beams, and VMAT plans were done for 360° arc with single arc or dual arc. The dose to the planning target volumes (PTV for 70, 63, and 56 Gy was compared. The dose to 95, 98, and 50% volume of PTV were analyzed. The homogeneity index (HI and the conformity index (CI of the PTV 70 were also analyzed. IMRT and VMAT plan showed similar dose coverage, HI, and CI. Maximum dose and dose to 1-cc volume of spinal cord, planning risk volume (PRV cord, and brain stem were compared. IMRT plan and VMAT plan showed similar results except for the 1 cc of PRV cord that received slightly higher dose in VMAT plan. Mean dose and dose to 50% volume of right and left parotid glands were analyzed. VMAT plan gave better sparing of parotid glands than IMRT. In normal tissue dose analyses VMAT was better than IMRT. The number of monitor units (MU required for delivering the good quality of the plan and the time required to deliver the plan for IMRT and VMAT were compared. The number of MUs for VMAT was higher than that of IMRT plans. However, the delivery time was reduced by a factor of two for VMAT compared with IMRT. VMAT plans yielded good quality of the plan compared with IMRT, resulting in reduced treatment time and improved efficiency for base of tongue cases.

  14. 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

  15. Intensity modulated radiotherapy as adjuvant post-operative treatment for retroperitoneal sarcoma: Acute toxicity; Radiotherapie avec modulation d'intensite dans le traitement postoperatoire des sarcomes retroperitoneaux: profil de toxicite aigue

    Energy Technology Data Exchange (ETDEWEB)

    Paumier, A.; Roberti, E.; Le Pechoux, C. [Departement de radiotherapie, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Bonvalot, S.; Rimareix, F. [Departement de chirurgie generale, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Beaudre, A.; Lefkopoulos, D. [Unite de physique, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Terrier, P. [Departement de biologie et de pathologie medicales, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Domont, J.; Le Cesne, A. [Departement de medecine oncologique, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France)

    2011-08-15

    Purpose. - To assess the acute toxicity of intensity modulated radiotherapy as post-operative adjuvant treatment for retroperitoneal sarcoma. Patients and methods. - Patients who received adjuvant intensity modulated radiotherapy from January 2009 to September 2010 were retrospectively reviewed. Results. - Fourteen patients entered the study (seven primary tumours and seven relapses). All tumours were liposarcoma and had macroscopically complete resection, epiploplasty was systematically realized. Median tumour size was 21 cm (range: 15-45), median planning target volume was 580 cm{sup 3} (range: 329-1172) and median prescribed dose was 50.4 Gy (range: 45-54). Median follow-up was 11.5 months (range: 2-21.4). Acute toxicity was mild: acute digestive toxicity grade 1-2 occurred in 12/14 patients (86%). However, there was no weight loss of more than 5% during radiotherapy and no treatment interruption was required. Two months after completion of radiotherapy, digestive toxicity grade 1 remained present in 1/14 patients (7%). One case of grade 3 toxicity occurred during follow-up (transient abdominal pain). Three relapses occurred: two were outside treaded volume and one was both in and outside treated volume. Conclusions. - Intensity modulated radiotherapy in the postoperative setting of retroperitoneal sarcoma provides low acute toxicity. Longer follow-up is needed to assess late toxicity, especially for bowel, kidney and radio-induced malignancies. (authors)

  16. Consensus guidelines for delineation of clinical target volume for intensity-modulated pelvic radiotherapy in postoperative treatment of endometrial and cervical cancer.

    Science.gov (United States)

    Small, William; Mell, Loren K; Anderson, Penny; Creutzberg, Carien; De Los Santos, Jennifer; Gaffney, David; Jhingran, Anuja; Portelance, Lorraine; Schefter, Tracey; Iyer, Revathy; Varia, Mahesh; Winter, Kathryn; Mundt, Arno J

    2008-06-01

    To develop an atlas of the clinical target volume (CTV) definitions for postoperative radiotherapy of endometrial and cervical cancer to be used for planning pelvic intensity-modulated radiotherapy. The Radiation Therapy Oncology Group led an international collaboration of cooperative groups in the development of the atlas. The groups included the Radiation Therapy Oncology Group, Gynecologic Oncology Group, National Cancer Institute of Canada, European Society of Therapeutic Radiology and Oncology, and American College of Radiology Imaging Network. The members of the group were asked by questionnaire to define the areas that were to be included in the CTV and to outline theses areas on individual computed tomography images. The initial formulation of the group began in late 2004 and culminated with a formal consensus conference in June 2005. The committee achieved a consensus CTV definition for postoperative therapy for endometrial and cervical cancer. The CTV should include the common, external, and internal iliac lymph node regions. The upper 3.0 cm of the vagina and paravaginal soft tissue lateral to the vagina should also be included. For patients with cervical cancer, or endometrial cancer with cervical stromal invasion, it is also recommended that the CTV include the presacral lymph node region. This report serves as an international template for the definition of the CTV for postoperative intensity-modulated radiotherapy for endometrial and cervical cancer.

  17. Monte Carlo calculations support organ sparing in Deep-Inspiration Breath-Hold intensity-modulated radiotherapy for locally advanced lung cancer

    DEFF Research Database (Denmark)

    Ottosson, Wiviann; Sibolt, Patrik; Larsen, Christina

    2015-01-01

    Background and purpose: Studies indicate that Deep-Inspiration Breath-Hold (DIBH) is advantageous over Free-Breathing (FB) for locally advanced lung cancer radiotherapy. However, these studies were based on simplified dose calculation algorithms, potentially critical due to the heterogeneous nature......) for intensity-modulated-radio therapy or volumetric-modulated-arc-therapy using 66 Gy in 33 fractions. All plans were re-calculated with MC. Results: Relative to FB, the total lung volume increased 86.8% in DIBH, while the gross tumor volume decreased 14.8%. MC revealed equally under- and over...

  18. Dosimetric and efficiency comparison of high-dose radiotherapy for esophageal cancer: volumetric modulated arc therapy versus fixed-field intensity-modulated radiotherapy.

    Science.gov (United States)

    Lin, C-Y; Huang, W-Y; Jen, Y-M; Chen, C-M; Su, Y-F; Chao, H-L; Lin, C-S

    2014-08-01

    The aim of this study was to compare high-dose volumetric modulated arc therapy (VMAT) and fixed-field intensity-modulated radiotherapy (ff-IMRT) plans for the treatment of patients with middle-thoracic esophageal cancer. Eight patients with cT2-3N0M0 middle-thoracic esophageal cancer were enrolled. The treatment planning system was the version 9 of the Pinnacle(3) with SmartArc (Philips Healthcare, Fitchburg, WI, USA). VMAT and ff-IMRT treatment plans were generated for each case, and both techniques were used to deliver 50 Gy to the planning target volume (PTV(50)) and then provided a 16-Gy boost (PTV(66)). The VMAT plans provided superior PTV(66) coverage compared with the ff-IMRT plans (P = 0.034), whereas the ff-IMRT plans provided more appropriate dose homogeneity to the PTV(50) (P = 0.017). In the lung, the V(5) and V(10) were lower for the ff-IMRT plans than for the VMAT plans, whereas the V(20) was lower for the VMAT plans. The delivery time was significantly shorter for the VMAT plans than for the ff-IMRT plans (P = 0.012). In addition, the VMAT plans delivered fewer monitor units. The VMAT technique required a shorter planning time than the ff-IMRT technique (3.8 ± 0.8 hours vs. 5.4 ± 0.6 hours, P = 0.011). The major advantages of VMAT plans are higher efficiency and an approximately 50% reduction in delivery time compared with the ff-IMRT plans, with comparable plan quality. Further clinical investigations to evaluate the use of high-dose VMAT for the treatment of esophageal cancer are warranted. © 2013 Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

  19. Propensity Score-based Comparison of Long-term Outcomes With 3-Dimensional Conformal Radiotherapy vs Intensity-Modulated Radiotherapy for Esophageal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Steven H., E-mail: SHLin@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wang Lu [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Myles, Bevan [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Thall, Peter F. [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hofstetter, Wayne L.; Swisher, Stephen G. [Department of Thoracic Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ajani, Jaffer A. [Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Cox, James D.; Komaki, Ritsuko; Liao Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-12-01

    Purpose: Although 3-dimensional conformal radiotherapy (3D-CRT) is the worldwide standard for the treatment of esophageal cancer, intensity modulated radiotherapy (IMRT) improves dose conformality and reduces the radiation exposure to normal tissues. We hypothesized that the dosimetric advantages of IMRT should translate to substantive benefits in clinical outcomes compared with 3D-CRT. Methods and Materials: An analysis was performed of 676 nonrandomized patients (3D-CRT, n=413; IMRT, n=263) with stage Ib-IVa (American Joint Committee on Cancer 2002) esophageal cancers treated with chemoradiotherapy at a single institution from 1998-2008. An inverse probability of treatment weighting and inclusion of propensity score (treatment probability) as a covariate were used to compare overall survival time, interval to local failure, and interval to distant metastasis, while accounting for the effects of other clinically relevant covariates. The propensity scores were estimated using logistic regression analysis. Results: A fitted multivariate inverse probability weighted-adjusted Cox model showed that the overall survival time was significantly associated with several well-known prognostic factors, along with the treatment modality (IMRT vs 3D-CRT, hazard ratio 0.72, P<.001). Compared with IMRT, 3D-CRT patients had a significantly greater risk of dying (72.6% vs 52.9%, inverse probability of treatment weighting, log-rank test, P<.0001) and of locoregional recurrence (P=.0038). No difference was seen in cancer-specific mortality (Gray's test, P=.86) or distant metastasis (P=.99) between the 2 groups. An increased cumulative incidence of cardiac death was seen in the 3D-CRT group (P=.049), but most deaths were undocumented (5-year estimate, 11.7% in 3D-CRT vs 5.4% in IMRT group, Gray's test, P=.0029). Conclusions: Overall survival, locoregional control, and noncancer-related death were significantly better after IMRT than after 3D-CRT. Although these results need

  20. Dosimetric benefit of DMLC tracking for conventional and sub-volume boosted prostate intensity-modulated arc radiotherapy

    Science.gov (United States)

    Pommer, Tobias; Falk, Marianne; Poulsen, Per R.; Keall, Paul J.; O’Brien, Ricky T.; Petersen, Peter Meidahl; Rosenschöld, Per Munck af

    2013-01-01

    This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose to the target volume and an intraprostatic lesion (IPL) boosted approach with an increased dose to a subvolume of the prostate. The impact on plan quality of optimizations with a leaf position constraint, which limited the distance between neighbouring adjacent MLC leaves, was also investigated. Deliveries were done with and without DMLC tracking on a linear acceleration with a high-resolution MLC. A cylindrical phantom containing two orthogonal diode arrays was used for dosimetry. A motion platform reproduced six patient-derived prostate motion traces, with the average displacement ranging from 1.0 to 8.9 mm during the first 75 seconds. A research DMLC tracking system was used for real-time motion compensation with optical monitoring for position input. The gamma index was used for evaluation, with measurements with a static phantom or the planned dose as reference, using 2% and 2 mm gamma criteria. The average pass rate with DMLC tracking was 99.9% (range 98.7–100%, measurement as reference), whereas the pass rate for untracked deliveries decreased distinctly as the average displacement increased, with an average pass rate of 61.3% (range 32.7–99.3%). Dose-volume histograms showed that DMLC tracking maintained the planned dose distributions in the presence of motion whereas traces with > 3 mm average displacement caused clear plan degradation for untracked deliveries. The dose to the rectum and bladder had an evident dependence on the motion direction and amplitude for untracked deliveries, and the dose to the rectum was slightly increased for IPL boosted plans compared to conventional plans for anterior motion with large amplitude. In conclusion, optimization using a leaf

  1. HybridArc: A novel radiation therapy technique combining optimized dynamic arcs and intensity modulation

    Energy Technology Data Exchange (ETDEWEB)

    Robar, James L., E-mail: james.robar@cdha.nshealth.ca [Department of Radiation Oncology, Dalhousie University, Halifax (Canada); Department of Physics and Atmospheric Science, Dalhousie University, Halifax (Canada); Thomas, Christopher [Department of Radiation Oncology, Dalhousie University, Halifax (Canada)

    2012-01-01

    This investigation focuses on possible dosimetric and efficiency advantages of HybridArc-a novel treatment planning approach combining optimized dynamic arcs with intensity-modulated radiation therapy (IMRT) beams. Application of this technique to two disparate sites, complex cranial tumors, and prostate was examined. HybridArc plans were compared with either dynamic conformal arc (DCA) or IMRT plans to determine whether HybridArc offers a synergy through combination of these 2 techniques. Plans were compared with regard to target volume dose conformity, target volume dose homogeneity, sparing of proximal organs at risk, normal tissue sparing, and monitor unit (MU) efficiency. For cranial cases, HybridArc produced significantly improved dose conformity compared with both DCA and IMRT but did not improve sparing of the brainstem or optic chiasm. For prostate cases, conformity was improved compared with DCA but not IMRT. Compared with IMRT, the dose homogeneity in the planning target volume was improved, and the maximum doses received by the bladder and rectum were reduced. Both arc-based techniques distribute peripheral dose over larger volumes of normal tissue compared with IMRT, whereas HybridArc involved slightly greater volumes of normal tissues compared with DCA. Compared with IMRT, cranial cases required 38% more MUs, whereas for prostate cases, MUs were reduced by 7%. For cranial cases, HybridArc improves dose conformity to the target. For prostate cases, dose conformity and homogeneity are improved compared with DCA and IMRT, respectively. Compared with IMRT, whether required MUs increase or decrease with HybridArc was site-dependent.

  2. Virtual bolus for inversely planned intensity modulated radiotherapy in adjuvant breast cancer treatment; Virtueller Bolus zur inversen Bestrahlungsplanung bei intensitaetsmodulierter Radiotherapie des Mammakarzinoms im Rahmen der adjuvanten Therapie

    Energy Technology Data Exchange (ETDEWEB)

    Thilmann, C.; Grosser, K.H.; Rhein, B.; Zabel, A. [Deutsches Krebsforschungszentrum Heidelberg (Germany). Klinische Kooperationseinheit Strahlentherapie; Wannenmacher, M. [Heidelberg Univ. (Germany). Klinische Radiologie; Debus, J. [Deutsches Krebsforschungszentrum Heidelberg (Germany). Klinische Kooperationseinheit Strahlentherapie; Heidelberg Univ. (Germany). Klinische Radiologie

    2002-03-01

    Background: Intensity modulated radiotherapy (IMRT) provides better sparing of normal tissue. We investigated the feasibility of inverse treatment planning for IMRT in adjuvant radiotherapy for breast cancer. Material and Methods: In addition to radiotherapy planning in conventional technique with tangential wedged 6-MV-photon beams we performed inversely planned IMRT (KonRad trademark). In the CT scans for treatment planning we defined a 10-mm bolus of -60 HE density. The influence of this bolus on planning optimization was determined by optimization without and dose calculation with and without bolus. Dose calculation after dose optimization with bolus was performed using different bolus thickness to determine the influence of the bolus on dose calculation. The results were compared with dose distribution in conventional technique. Results: Inverse optimization with a dose algorithm which considers tissue inhomogeneity results in unintended dose increase at the patient surface. With a virtual 10-mm bolus used for inverse optimization the dose increase was reduced. Thus, skin sparing was identical to conventional planning. The relative dose distribution was negligibly affected by the use of a 10-mm bolus. Difference in absolute dose was 3.4% compared to calculation without bolus. Therefore, the bolus must be removed before final dose calculation. (orig.) [German] Fragestellung: Die intensitaetsmodulierte Strahlenbehandlung (IMRT) verspricht eine verbesserte Schonung von Risikostrukturen. Wir untersuchten, in welcher Form eine inverse Bestrahlungsplanung zur IMRT der Restbrust beim Mammakarzinom durchfuehrbar ist. Methodik: Neben einer Bestrahlungsplanung in konventioneller Technik mit tangentialen 6-MB-Keilfilter-Feldern wurde eine IMRT-Bestrahlungsplanung mit inverser Planoptimierung (KonRad trademark) durchgefuehrt. Im Planungs-CT wurde ein Bolus von 10 mm Dicke und einer Dichte von -60 HE definiert. Der Einfluss des Bolus auf die Planoptimierung wurde bestimmt

  3. Development of a quality control system in intensity modulated radiotherapy (IMRT); Desenvolvimento de um sistema para controle de qualidade em radioterapia de intensidade modulada (IMRT)

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Roberto Salomon de, E-mail: salomon@inca.gov.br [Instituto Nacional de Cancer (PQRT/INCA), Rio de Janeiro, RJ (Brazil). Programa de Qualidade em Radioterapia; Rosa, Luiz A.R. da, E-mail: lrosa@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Braz, Delson, E-mail: delson@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), RJ (Brazil)

    2013-11-01

    The more complex the technique of radiotherapy is, the more refined the quality control must be. The technique of Intensity Modulated Radiotherapy (IMRT) is one of the technological innovations that gained space in the whole worlds in the last decade whose parameters of quality control are not fully established yet. The present work developed a phantom for quality control in IMRT to be implemented in the routine of the Radiotherapy Quality Control Program (PQRT) of the Brazilian National Cancer Institute (INCa). The device consists of a block formed by several polystyrene slice with TDLs and radiochromic film inserted. It should be sent (or taken) to the Program participating institutions to be irradiated under certain conditions and then be returned to the PQRT., where the discrepancy degree between the planned treatment and those effectively delivered will be evaluated. The system was validated through the test cases and the pilot program preformed in nine radiotherapy centers that perform IMRT in the southeast region of Brazil. (author)

  4. Volumetric modulated arc therapy is superior to conventional intensity modulated radiotherapy - a comparison among prostate cancer patients treated in an Australian centre

    Directory of Open Access Journals (Sweden)

    Haydu Lauren E

    2011-09-01

    Full Text Available Abstract Background Radiotherapy technology is expanding rapidly. Volumetric Modulated Arc Therapy (VMAT technologies such as RapidArc® (RA may be a more efficient way of delivering intensity-modulated radiotherapy-like (IM treatments. This study is an audit of the RA experience in an Australian department with a planning and economic comparison to IM. Methods 30 consecutive prostate cancer patients treated radically with RA were analyzed. Eight RA patients treated definitively were then completely re-planned with 3D conformal radiotherapy (3D; and a conventional sliding window IM technique; and a new RA plan. The acceptable plans and their treatment times were compared and analyzed for any significant difference. Differences in staff costs of treatment were computed and analyzed. Results Thirty patients had been treated to date with eight being treated definitely to at least 74 Gy, nine post high dose brachytherapy (HDR to 50.4Gy and 13 post prostatectomy to at least 64Gy. All radiotherapy courses were completed with no breaks. Acute rectal toxicity by the RTOG criteria was acceptable with 22 having no toxicity, seven with grade 1 and one had grade 2. Of the eight re-planned patients, none of the 3D (three-dimensional conformal radiotherapy plans were acceptable based on local guidelines for dose to organs at risk. There was no statistically significant difference in planning times between IM and RA (p = 0.792. IM had significantly greater MUs per fraction (1813.9 vs 590.2 p Conclusions 3D was incapable of covering a modern radiotherapy volume for the radical treatment of prostate cancer. These volumes can be treated via conventional IM and RA. RA was significantly more efficient, safe and cost effective than IM. VMAT technologies are a superior way of delivering IM-like treatments.

  5. 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)

  6. The Treatment of Pelvic Locoregional Recurrence of Cervical Cancer After Radical Surgery With Intensity-Modulated Radiation Therapy Compared With Conventional Radiotherapy: A Retrospective Study.

    Science.gov (United States)

    Yin, Yue-ju; Li, Hui-qin; Sheng, Xiu-gui; Du, Xue-lian; Wang, Cong; Lu, Chun-hua; Pan, Chun-xia

    2015-07-01

    The aim of this study was to investigate the therapeutic response and toxicity of intensity-modulated radiation therapy (IMRT) or conventional radiotherapy (c-RT) as adjuvant therapy in patients with pelvic locoregional recurrence of cervical cancer after radical surgery. This retrospective study included 161 patients with unresectable pelvic locoregional recurrence of cervical cancer after radical surgery between March 2003 and May 2012. All patients were initially diagnosed with International Federation of Gynecology and Obstetrics stage IB-IIA cervical cancer and received radical hysterectomy and pelvic lymphadenectomy. A total of 82 patients were treated with c-RT, whereas the remaining 79 patients underwent IMRT. Intracavitary brachytherapy and concurrent chemotherapy were performed during external irradiation. The mean dose delivered to the planning target volume was significantly higher in the IMRT group than in the c-RT group (61.8 vs 50.3 Gy, P = 0.029). Intensity-modulated radiation therapy plans yielded better dose sparing of small bowel, bladder, and rectum than did c-RT (P cervical cancer after radical surgery. The acute and chronic toxicities were acceptable, and the adjacent organs at risk were well protected.

  7. Dosimetric comparison of intensity-modulated, conformal, and four-field pelvic radiotherapy boost plans for gynecologic cancer: a retrospective planning study

    Directory of Open Access Journals (Sweden)

    Perkins Gregory

    2006-05-01

    Full Text Available Abstract Purpose To evaluate intensity-modulated radiation therapy (IMRT as an alternative to conformal radiotherapy (CRT or 4-field box boost (4FB in women with gynecologic malignancies who are unsuitable for brachytherapy for technical or medical reasons. Methods Dosimetric and toxicity information was analyzed for 12 patients with cervical (8, endometrial (2 or vaginal (2 cancer previously treated with external beam pelvic radiotherapy and a CRT boost. Optimized IMRT boost treatment plans were then developed for each of the 12 patients and compared to CRT and 4FB plans. The plans were compared in terms of dose conformality and critical normal tissue avoidance. Results The median planning target volume (PTV was 151 cm3 (range 58–512 cm3. The median overlap of the contoured rectum with the PTV was 15 (1–56 %, and 11 (4–35 % for the bladder. Two of the 12 patients, both with large PTVs and large overlap of the contoured rectum and PTV, developed grade 3 rectal bleeding. The dose conformity was significantly improved with IMRT over CRT and 4FB (p ≤ 0.001 for both. IMRT also yielded an overall improvement in the rectal and bladder dose-volume distributions relative to CRT and 4FB. The volume of rectum that received the highest doses (>66% of the prescription was reduced by 22% (p Conclusion These results indicate that IMRT can improve target coverage and reduce dose to critical structures in gynecologic patients receiving an external beam radiotherapy boost. This dosimetric advantage will be integrated with other patient and treatment-specific factors, particularly internal tumor movement during fractionated radiotherapy, in the context of a future image-guided radiation therapy study.

  8. Re-irradiation of unresectable recurrent head and neck cancer: using Helical Tomotherapy as image-guided intensity-modulated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Songmi; Yoo, Eun Jung; Kim, Ji Yoon; Han, Chi Wha; Kim, Ki Jun; Kay, Chul Seung [The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

    2013-12-15

    Re-irradiation (re-RT) is considered a treatment option for inoperable locoregionally recurrent head and neck cancer (HNC) after prior radiotherapy. We evaluated the efficacy and safety of re-RT using Helical Tomotherapy as image-guided intensity-modulated radiotherapy in recurrent HNC. Patients diagnosed with recurrent HNC and received re-RT were retrospectively reviewed. Primary endpoint was overall survival (OS) and secondary endpoints were locoregional control and toxicities. The median follow-up period of total 9 patients was 18.7 months (range, 4.1 to 76 months) and that of 3 alive patients was 49 months (range, 47 to 76 months). Median dose of first radiotherapy and re-RT was 64.8 and 47.5 Gy10. Median cumulative dose of the two courses of radiotherapy was 116.3 Gy10 (range, 91.8 to 128.9 Gy10) while the median interval between the two courses of radiation was 25 months (range, 4 to 137 months). The response rate after re-RT of the evaluated 8 patients was 75% (complete response, 4; partial response, 2). Median locoregional relapse-free survival after re-RT was 11.9 months (range, 3.4 to 75.1 months) and 5 patients eventually presented with treatment failure (in-field failure, 2; in- and out-field failure, 2; out-field failure, 1). Median OS of the 8 patients was 20.3 months (range, 4.1 to 75.1 months). One- and two-year OS rates were 62.5% and 50%, respectively. Grade 3 leucopenia developed in one patient as acute toxicity, and grade 2 osteonecrosis and trismus as chronic toxicity in another patient. Re-RT using Helical Tomotherapy for previously irradiated patients with unresectable locoregionally recurrent HNC may be a feasible treatment option with long-term survival and acceptable toxicities.

  9. SU-E-P-58: Dosimetric Study of Conventional Intensity-Modulated Radiotherapy and Knowledge-Based Radiation Therapy for Postoperation of Cervix Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C; Yin, Y [Shandong Tumor Hospital, Jinan, Shandong Provice (China)

    2015-06-15

    Purpose: To compare the dosimetric difference of the target volume and organs at risk(OARs) between conventional intensity-modulated radiotherapy(C-IMRT) and knowledge-based radiation therapy (KBRT) plans for cervix cancer. Methods: 39 patients with cervical cancer after surgery were randomly selected, 20 patient plans were used to create the model, the other 19 cases used for comparative evaluation. All plans were designed in Eclipse system. The prescription dose was 30.6Gy, 17 fractions, OARs dose satisfied to the clinical requirement. A paired t test was used to evaluate the differences of dose-volume histograms (DVH). Results: Comparaed to C-IMRT plan, the KBRT plan target can achieve the similar target dose coverage, D98,D95,D2,HI and CI had no difference (P≥0.05). The dose of rectum, bladder and femoral heads had no significant differences(P≥0.05). The time was used to design treatment plan was significant reduced. Conclusion: This study shows that postoperative radiotherapy of cervical KBRT plans can achieve the similar target and OARs dose, but the shorter designing time.

  10. Feasibility of a 3D-printed anthropomorphic patient-specific head phantom for patient-specific quality assurance of intensity-modulated radiotherapy

    Science.gov (United States)

    Yea, Ji Woon; Park, Jae Won; Kim, Sung Kyu; Kim, Dong Youn; Kim, Jae Gu; Seo, Chan Young; Jeong, Won Hyo; Jeong, Man Youl

    2017-01-01

    This study evaluated the feasibility of utilizing a 3D-printed anthropomorphic patient-specific head phantom for patient-specific quality assurance (QA) in intensity-modulated radiotherapy (IMRT). Contoured left and right head phantoms were converted from DICOM to STL format. Fused deposition modeling (FDM) was used to construct an anthropomorphic patient-specific head phantom with a 3D printer. An established QA technique and the patient-specific head phantom were used to compare the calculated and measured doses. When the established technique was used to compare the calculated and measured doses, the gamma passing rate for γ ≤ 1 was 97.28%, while the gamma failure rate for γ > 1 was 2.72%. When the 3D-printed patient-specific head phantom was used, the gamma passing rate for γ ≤ 1 was 95.97%, and the gamma failure rate for γ > 1 was 4.03%. The 3D printed patient-specific head phantom was concluded to be highly feasible for patient-specific QA prior to complicated radiotherapy procedures such as IMRT. PMID:28727787

  11. Impact of gantry rotation time on plan quality and dosimetric verification--volumetric modulated arc therapy (VMAT) vs. intensity modulated radiotherapy (IMRT).

    Science.gov (United States)

    Pasler, Marlies; Wirtz, Holger; Lutterbach, Johannes

    2011-12-01

    To compare plan quality criteria and dosimetric accuracy of step-and-shoot intensity-modulated radiotherapy (ss-IMRT) and volumetric modulated arc radiotherapy (VMAT) using two different gantry rotation times. This retrospective planning study based on 20 patients was comprised of 10 prostate cancer (PC) and 10 head and neck (HN) cancer cases. Each plan contained two target volumes: a primary planning target volume (PTV) and a boost volume. For each patient, one ss-IMRT plan and two VMAT plans at 90 s (VMAT90) and 120 s (VMAT120) per arc were generated with the Pinnacle© planning system. Two arcs were provided for the PTV plans and a single arc for boost volumes. Dosimetric verification of the plans was performed using a 2D ionization chamber array placed in a full scatter phantom. VMAT reduced delivery time and monitor units for both treatment sites compared to IMRT. VMAT120 vs. VMAT90 increased delivery time and monitor units in PC plans without improving plan quality. For HN cases, VMAT120 provided comparable organs at risk sparing and better target coverage and conformity than VMAT90. In the VMAT plan verification, an average of 97.1% of the detector points passed the 3 mm, 3% γ criterion, while in IMRT verification it was 98.8%. VMAT90, VMAT120, and IMRT achieved comparable treatment plans. Slower gantry movement in VMAT120 plans only improves dosimetric quality for highly complex targets.

  12. SU-E-T-175: Clinical Evaluations of Monte Carlo-Based Inverse Treatment Plan Optimization for Intensity Modulated Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Y; Li, Y; Tian, Z; Gu, X; Jiang, S; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2015-06-15

    Purpose: Pencil-beam or superposition-convolution type dose calculation algorithms are routinely used in inverse plan optimization for intensity modulated radiation therapy (IMRT). However, due to their limited accuracy in some challenging cases, e.g. lung, the resulting dose may lose its optimality after being recomputed using an accurate algorithm, e.g. Monte Carlo (MC). It is the objective of this study to evaluate the feasibility and advantages of a new method to include MC in the treatment planning process. Methods: We developed a scheme to iteratively perform MC-based beamlet dose calculations and plan optimization. In the MC stage, a GPU-based dose engine was used and the particle number sampled from a beamlet was proportional to its optimized fluence from the previous step. We tested this scheme in four lung cancer IMRT cases. For each case, the original plan dose, plan dose re-computed by MC, and dose optimized by our scheme were obtained. Clinically relevant dosimetric quantities in these three plans were compared. Results: Although the original plan achieved a satisfactory PDV dose coverage, after re-computing doses using MC method, it was found that the PTV D95% were reduced by 4.60%–6.67%. After re-optimizing these cases with our scheme, the PTV coverage was improved to the same level as in the original plan, while the critical OAR coverages were maintained to clinically acceptable levels. Regarding the computation time, it took on average 144 sec per case using only one GPU card, including both MC-based beamlet dose calculation and treatment plan optimization. Conclusion: The achieved dosimetric gains and high computational efficiency indicate the feasibility and advantages of the proposed MC-based IMRT optimization method. Comprehensive validations in more patient cases are in progress.

  13. Investigation of intensity-modulated radiotherapy optimization with gEUD-based objectives by means of simulated annealing.

    Science.gov (United States)

    Hartmann, Matthias; Bogner, Ludwig

    2008-05-01

    Inverse treatment planning of intensity-modulated radiation therapy (IMRT) is complicated by several sources of error, which can cause deviations of optimized plans from the true optimal solution. These errors include the systematic and convergence error, the local minima error, and the optimizer convergence error. We minimize these errors by developing an inverse IMRT treatment planning system with a Monte Carlo based dose engine and a simulated annealing search engine as well as a deterministic search engine. In addition, different generalized equivalent uniform dose (gEUD)-based and hybrid objective functions were implemented and investigated with simulated annealing. By means of a head-and-neck IMRT case we have analyzed the properties of these gEUD-based objective functions, including its search space and the existence of local optima errors. We found evidence that the use of a previously published investigation of a gEUD-based objective function results in an uncommon search space with a golf hole structure. This special search space structure leads to trapping in local minima, making it extremely difficult to identify the true global minimum, even when using stochastic search engines. Moreover, for the same IMRT case several local optima have been detected by comparing the solutions of 100 different trials using a gradient optimization algorithm with the global optimum computed by simulated annealing. We have demonstrated that the hybrid objective function, which includes dose-based objectives for the target and gEUD-based objectives for normal tissue, results in equally good sparing of the critical structures as for the pure gEUD objective function and lower target dose maxima.

  14. Prospective assessment of the quality of life before, during and after image guided intensity modulated radiotherapy for prostate cancer

    DEFF Research Database (Denmark)

    Sveistrup, Joen; Mortensen, Ole Steen; Bjørner, Jakob B.

    2016-01-01

    BACKGROUND: Radiotherapy (RT) in combination with androgen deprivation therapy (ADT) for prostate cancer (PCa) carries a risk of gastrointestinal (GI) and genitourinary toxicity, which might affect the quality of life (QoL). The purpose of this study was to assess the QoL in patients with PCa...... before, during and after radiotherapy (RT) and to compare the QoL 1 year after RT to a normal population. METHODS: The QoL was evaluated prospectively by the self-administered questionnaire SF-36 in 87 patients with PCa. The SF-36 was completed before RT (baseline), at start of RT, at end of RT and 1...... year after RT. A mixed model analysis was used to determine the changes in QoL at each time point compared to baseline. The patients' QoL 1 year after RT was compared to a normal population consisting of 462 reference subjects matched on age and education. RESULTS: One year after RT, patients reported...

  15. Three-dimensional customized bolus for intensity-modulated radiotherapy in a patient with Kimura's disease involving the auricle.

    Science.gov (United States)

    Park, J W; Yea, J W

    2016-05-01

    In radiotherapy, a commercial bolus often does not provide a suitable fit over irregular surfaces. To address this issue, we fabricated a customized bolus using 3D printing technology. The aim of our study was to evaluate the application of this 3D-printed bolus in a clinical setting. The patient was a 45-year-old man with recurrent Kimura's disease involving the auricle, receiving radiotherapy in our oncology department. A customized bolus, 5mm in thickness, was fabricated based on reconstruction of computed tomography (CT) images. The bolus was printed on a Dimension 1200 series SST 3D printer. Repeat CT-based simulation indicated an acceptable fit of the 3D-printed bolus to the target region, with a maximum air gap of less than 5mm at the tragus. Most of the surface area of the target region was covered by the 95% isodose line. The plan with the 3D-printed bolus improved target coverage compared to that without a bolus. And the plan with the 3D-printed bolus yielded comparable results to those with the paraffin wax bolus. In conclusion, a customized bolus using a 3D printer was successfully applied to an irregular surface.

  16. Dosimetric effects of multileaf collimator leaf width on intensity-modulated radiotherapy for head and neck cancer.

    Science.gov (United States)

    Hong, Chae-Seon; Ju, Sang Gyu; Kim, Minkyu; Kim, Jung-In; Kim, Jin Man; Suh, Tae-Suk; Han, Youngyih; Ahn, Yong Chan; Choi, Doo Ho; Nam, Heerim; Park, Hee Chul

    2014-02-01

    The authors evaluated the effects of multileaf collimator (MLC) leaf width (2.5 vs. 5 mm) on dosimetric parameters and delivery efficiencies of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) for head and neck (H&N) cancers. The authors employed two types of mock phantoms: large-sized head and neck (LH&N) and small-sized C-shape (C-shape) phantoms. Step-and-shoot IMRT (S&S_IMRT) and VMAT treatment plans were designed with 2.5- and 5.0-mm MLC for both C-shape and LH&N phantoms. Their dosimetric characteristics were compared in terms of the conformity index (CI) and homogeneity index (HI) for the planning target volume (PTV), the dose to organs at risk (OARs), and the dose-spillage volume. To analyze the effects of the field and arc numbers, 9-field IMRT (9F-IMRT) and 13-field IMRT (13F-IMRT) plans were established for S&S_IMRT. For VMAT, single arc (VMAT1) and double arc (VMAT2) plans were established. For all plans, dosimetric verification was performed using the phantom to examine the relationship between dosimetric errors and the two leaf widths. Delivery efficiency of the two MLCs was compared in terms of beam delivery times, monitor units (MUs) per fraction, and the number of segments for each plan. 2.5-mm MLC showed better dosimetric characteristics in S&S_IMRT and VMAT for C-shape, providing better CI for PTV and lower spinal cord dose and high and intermediate dose-spillage volume as compared with the 5-mm MLC (p 0.05). Further, beam delivery efficiency was not observed to be significantly associated with leaf width for either C-shape or LH&N. However, MUs per fraction were significantly reduced for the 2.5-mm MLC for the LH&N. In dosimetric error analysis, absolute dose evaluations had errors of less than 3%, while the Gamma passing rate was greater than 95% according to the 3%/3 mm criteria. There were no significant differences in dosimetric error between the 2.5- and 5-mm MLCs. As compared with MLC of 5-mm leaf

  17. SU-E-T-483: In Vivo Dosimetry of Conventional and Rotational Intensity Modulated Radiotherapy Using Integral Quality Monitor (IQM)

    Energy Technology Data Exchange (ETDEWEB)

    Lin, L; Qian, J; Gonzales, R; Keck, J; Armour, E; Wong, J [Johns Hopkins University, Baltimore, MD (United States)

    2015-06-15

    Purpose: To investigate the accuracy, sensitivity and constancy of integral quality monitor (IQM), a new system for in vivo dosimetry of conventional intensity modulated radiation therapy (IMRT) or rotational volumetric modulated arc therapy (VMAT) Methods: A beta-version IQM system was commissioned on an Elekta Infinity LINAC equipped with 160-MLCs Agility head. The stationary and rotational dosimetric constancy of IQM was evaluated, using five-field IMRT and single-or double-arc VMAT plans for prostate and head-and-neck (H&N) patients. The plans were delivered three times over three days to assess the constancy of IQM response. Picket fence (PF) fields were used to evaluate the sensitivity of detecting MLC leaf errors. A single leaf offset was intentionally introduced during delivery of various PF fields with segment apertures of 3×1, 5×1, 10×1, and 24×1cm2. Both 2mm and 5mm decrease in the field width were used. Results: Repeated IQM measurements of prostate and H&N IMRT deliveries showed 0.4 and 0.5% average standard deviation (SD) for segment-by-segment comparison and 0.1 and 0.2% for cumulative comparison. The corresponding SDs for VMAT deliveries were 6.5, 9.4% and 0.7, 1.3%, respectively. Statistical analysis indicates that the dosimetric differences detected by IQM were significant (p < 0.05) in all PF test deliveries. The largest average IQM signal response of a 2 mm leaf error was found to be 2.1% and 5.1% by a 5mm leaf error for 3×1 cm2 field size. The same error in 24×1 cm2 generates a 0.7% and 1.4% difference in the signal. Conclusion: IQM provides an effective means for real-time dosimetric verification of IMRT/ VMAT treatment delivery. For VMAT delivery, the cumulative dosimetry of IQM needs to be used in clinical practice.

  18. Therapeutic effect and prognostic analysis of intensity-modulated radiotherapy for primary hepatocellular carcinoma with portal vein and/or inferior vena cava tumor thrombus

    Directory of Open Access Journals (Sweden)

    HUANG Long

    2015-06-01

    Full Text Available ObjectiveTo determine the efficacy and prognostic factors of intensity-modulated radiotherapy (IMRT for primary hepatocellular carcinoma (HCC with portal vein and/or inferior vena cava tumor thrombus. MethodsTwenty-three HCC patients with portal vein and/or inferior vena cava tumor thrombus received IMRT with an 8 MV linear accelerator at the Cancer Center of General Hospital of Armed Police Forces, Anhui Medical University, from April 2008 to August 2011. A single dose of 3 to 6 Gy was delivered at five fractions per week, with a total dose of 56 to 96 Gy and a median dose of 60 Gy. Survival time was recorded, and adverse reactions were evaluated. Survival rate calculation and survival analysis were performed using the Kaplan-Meier method. Comparison of categorical between two groups was made by chi-square test. ResultsOne patient did not complete radiotherapy due to upper gastrointestinal bleeding. Of 22 patients who completed IMRT, 4 achieved complete remission and 10 achieved partial remission, with an overall response rate of 63.7%. Our analysis showed that the type of tumor thrombus and tumor size were associated with tumor response rate and were significant prognostic factors (P<0.05. The median survival time was 13.4 months. The 1-, 2-, and 3-year survival rates were 59%, 27%, and 18%, respectively. The 22 patients who completed radiotherapy did not experience acute radiation injury or late adverse outcomes such as radiation-induced liver disease. ConclusionThis study suggests IMRT is a safe and effective treatment option for HCC patients with portal vein and/or inferior vena cava tumor thrombus.

  19. Dosimetric analysis of tomotherapy-based intensity-modulated radiotherapy with and without bone marrow sparing for the treatment of cervical cancer

    Institute of Scientific and Technical Information of China (English)

    Fuli Zhang; Jianping Chen; Heliang He; Weidong Xu; Huayong Jiang; Yadi Wang ; Junmao Gao; Qingzhi Liu; Na Lu; Diandian Chen; Bo Yao

    2015-01-01

    Objective The aim of the study was to compare tomotherapy-based bone marrow-sparing intensity-mod-ulated radiotherapy (BMS-IMRT) with intensity-modulated radiotherapy (IMRT) without entering the pelvic bone marrow as a planning constraint in the treatment of cervical cancer after hysterectomy. Methods BMS-IMRT and IMRT plans were designed for a cohort of nine patients. The prescribed dose was 45 Gy in 1.8 Gy daily fractions, and 95% of the planned target volume received this dose. The doses were computed using a commercial y available treatment planning system with the convolution/superposi-tion algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices (HI and CI) as wel as organ at risk dose and volume parameters. Results BMS-IMRT had advantages over IMRT in terms of CI, but was equivalent to the latter in HI. V5, V10, V20, V30, and V40 of pelvic bone marrow in BMS-IMRT decreased by 0.06%, 17.33%, 22.19%, 13.85%, and 16.46%, respectively, compared with IMRT. Except for V30 of the smal bowel and V30 and V40 of the bladder, no statistical y significant dif erences were found between BMS-IMRT and IMRT in the smal bowel, bladder, and rectum. Conclusion For cervical cancer patients receiving tomotherapy-based radiotherapy after hysterectomy, BMS-IMRT reduced pelvic bone marrow volume receiving low-dose radiation, and it may be conducive to preventing acute hematologic toxicity.

  20. Intensity modulated radiotherapy as neoadjuvant chemoradiation for the treatment of patients with locally advanced pancreatic cancer. Outcome analysis and comparison with a 3D-treated patient cohort

    Energy Technology Data Exchange (ETDEWEB)

    Combs, S.E.; Habermehl, D.; Kessel, K.; Brecht, I. [Univ. Hospital of Heidelberg (Germany). Dept. of Radiation Oncology; Bergmann, F.; Schirmacher, P. [Univ. Hospital of Heidelberg (Germany). Dept. of Pathology; Werner, J.; Buechler, M.W. [Univ. Hospital of Heidelberg (Germany). Dept. of Surgery; Jaeger, D. [National Center for Tumor Diseases (NCT), Heidelberg (Germany); Debus, J. [Univ. Hospital of Heidelberg (Germany). Dept. of Radiation Oncology; Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Clinical Cooperation Unit Radiation Oncology

    2013-09-15

    Background: To evaluate outcome after intensity modulated radiotherapy (IMRT) compared to 3D conformal radiotherapy (3D-RT) as neoadjuvant treatment in patients with locally advanced pancreatic cancer (LAPC). Materials and methods: In total, 57 patients with LAPC were treated with IMRT and chemotherapy. A median total dose of 45 Gy to the PTV {sub baseplan} and 54 Gy to the PTV {sub boost} in single doses of 1.8 Gy for the PTV {sub baseplan} and median single doses of 2.2 Gy in the PTV {sub boost} were applied. Outcomes were evaluated and compared to a large cohort of patients treated with 3D-RT. Results: Overall treatment was well tolerated in all patients and IMRT could be completed without interruptions. Median overall survival was 11 months (range 5-37.5 months). Actuarial overall survival at 12 and 24 months was 36 % and 8 %, respectively. A significant impact on overall survival could only be observed for a decrease in CA 19-9 during treatment, patients with less pre-treatment CA 19-9 than the median, as well as weight loss during treatment. Local progression-free survival was 79 % after 6 months, 39 % after 12 months, and 13 % after 24 months. No factors significantly influencing local progression-free survival could be identified. There was no difference in overall and progression-free survival between 3D-RT and IMRT. Secondary resectability was similar in both groups (26 % vs. 28 %). Toxicity was comparable and consisted mainly of hematological toxicity due to chemotherapy. Conclusion: IMRT leads to a comparable outcome compared to 3D-RT in patients with LAPC. In the future, the improved dose distribution, as well as advances in image-guided radiotherapy (IGRT) techniques, may improve the use of IMRT in local dose escalation strategies to potentially improve outcome. (orig.)

  1. Dose-Escalated Hypofractionated Intensity-Modulated Radiotherapy in High-Risk Carcinoma of the Prostate: Outcome and Late Toxicity

    Directory of Open Access Journals (Sweden)

    David Thomson

    2012-01-01

    Results. Median followup was 84 months. Five-year overall survival (OS was 83% and biochemical progression-free survival (bPFS was 50% for 57 Gy. Five-year OS was 75% and bPFS 58% for 60 Gy. At 7 years, toxicity by RTOG criteria was acceptable with no grade 3 or above toxicity. Compared with baseline, there was no significant change in urinary symptoms at 2 or 7 years. Bowel symptoms were stable between 2 and 7 years. All patients continued to have significant sexual dysfunction. Conclusion. In high-risk prostate cancer, dose-escalated hypofractionated radiotherapy using IMRT results in encouraging outcomes and acceptable late toxicity.

  2. Dosimetric comparison between volumetric modulated arc therapy and fixed-gantry dynamic intensity modulated radiation therapy for rectal cancer radiotherapy%直肠癌旋转容积调强与固定野动态调强的剂量学比较

    Institute of Scientific and Technical Information of China (English)

    花威; 李军; 谭飞; 陈婷婷; 汪步海

    2012-01-01

    目的:比较旋转容积调强(VMAT)与固定野动态调强(dIMRT)在直肠癌放疗计划中的剂量学差异.方法:8例直肠癌患者利用瓦里安计划系统(Eclipse 8.6)分别进行VMAT和dIMRT放射治疗计划设计.利用剂量体积直方图来比较两种计划中靶区和危及器官的剂量学差异.结果:与dIMRT相比,VMAT靶区适合度指数(CI)、靶区剂量均匀性指数(HI)均更接近1,Dmin为(43.403±0.486)Gy,更接近处方剂量,差异有统计学意义,P<0.05.在VMAT计划中小肠的D30%、D50%和Dmean分别为(25.918±1.216)、(22.340士3.784)和(23.547±2.863) Gy,低于dIMRT计划的(28.073±3.114)、(24.172±2.540)和(25.257±1.374) Gy,P值分别为0.00、0.01和0.00;膀胱的D30%为(35.380±2.734) Gy,较dIMRT的(30.123±2.209) Gy偏高,P=0.00,但仍远低于剂量限值;股骨头的D5%和Dmean分别为(31.344±3.556)和(20.179±3.017) Gy,显著高于dIMRT计划的(26.731±2.828)和(17.459±3.279) Gy,P值均为0.00.VMAT总MU减少52.7%,治疗时间仅为dIMRT的1/4.结论:VMAT计划可以达到或优于dIMRT计划的靶区剂量分布,能更好地降低部分危及器官的受照剂量,并且具有较少总MU、总治疗时间的优势,减少了治疗中不确定性因素的影响及患者不适感.%OBJECTIVE: To compare the dosimetric difference between volumetric modulated arc therapy(VMAT) and fixed-gantry dynamic intensity modulated radiation therapy(dIMRT) for rectal cancer. METHODS: VMAT and dlM-RT treatment plans of 8 rectal cancer cases were generated by Vrian Eclipse ver8. 6 treatment planning systerm. Dose volume histograms were used to compare the target volume and organs at risks. RESULTS: Compared to dIMRT,conformity index(CI) and homogeneity index(HI) of VMAT closer to one. Dmin of VMAT was (43. 403 ± 0. 486) Gy,closer to prescription dose. There were significant differences in CI,HI and Dmin(P<0. 05). The small intestinal's D30% ,D50% and Dmean were larger in dIMRT than those in VAMT(P values were

  3. Definition and visualisation of regions of interest in post-prostatectomy image-guided intensity modulated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Linda J, E-mail: linda.bell1@health.nsw.gov.au; Cox, Jennifer [Radiation Oncology Department, Northern Sydney Cancer Centre, Royal North Shore Hospital, St Leonards, New South Wales (Australia); Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales (Australia); Eade, Thomas; Rinks, Marianne; Kneebone, Andrew [Radiation Oncology Department, Northern Sydney Cancer Centre, Royal North Shore Hospital, St Leonards, New South Wales (Australia)

    2014-09-15

    Standard post-prostatectomy radiotherapy (PPRT) image verification uses bony anatomy alignment. However, the prostate bed (PB) moves independently of bony anatomy. Cone beam computed tomography (CBCT) can be used to soft tissue match, so radiation therapists (RTs) must understand pelvic anatomy and PPRT clinical target volumes (CTV). The aims of this study are to define regions of interest (ROI) to be used in soft tissue matching image guidance and determine their visibility on planning CT (PCT) and CBCT. Published CTV guidelines were used to select ROIs. The PCT scans (n = 23) and CBCT scans (n = 105) of 23 post-prostatectomy patients were reviewed. Details on ROI identification were recorded. Eighteen patients had surgical clips. All ROIs were identified on PCTs at least 90% of the time apart from mesorectal fascia (MF) (87%) due to superior image quality. When surgical clips are present, the seminal vesicle bed (SVB) was only seen in 2.3% of CBCTs and MF was unidentifiable. Most other structures were well identified on CBCT. The anterior rectal wall (ARW) was identified in 81.4% of images and penile bulb (PB) in 68.6%. In the absence of surgical clips, the MF and SVB were always identified; the ARW was identified in 89.5% of CBCTs and PB in 73.7%. Surgical clips should be used as ROIs when present to define SVB and MF. In the absence of clips, SVB, MF and ARW can be used. RTs must have a strong knowledge of soft tissue anatomy and PPRT CTV to ensure coverage and enable soft tissue matching.

  4. Differences between ceryical cancer radical radiotherapy dose intensity modulated rotary positiye displacement technology and dynamic fixed field IMRT technology%宫颈癌根治性放疗旋转容积调强技术及固定野动态调强放疗技术的剂量学差异

    Institute of Scientific and Technical Information of China (English)

    徐洋; 刘东丽; 张佩娟; 齐华; 陈菁

    2016-01-01

    Objectiye To analysis the metrology differences of cervical cancer radical radiotherapy IMRT technology transfer volume (VMAT)and the fixed field IMRT dynamic technology(9 - IMRT)and compare the threaten to the organs at risk and the accelerator hops. Methods 15 cases of cervical cancer author Radiology radical radiotherapy on CT images with a 2 and 9 arc VMAAT field IMRT plan were col-lected. Target volume dose differences,target dose conformal and uniform organ dosimetry differences in degree of the two radiotherapy planning were compared. The threaten to the organs at risk and the accelerator hops between the two groups were compared. Results Compared with 9 -IMRT,VMAT dose distribution uniformity(HI)and conformal(CI)was more preferably( P 0. 05). The average number of machine hop between VMAT plan(756. 85 ± 134. 62)and 9 - IM-RT plan(1 104. 12 ± 186. 97)had significant difference( P < 0. 05). Conclusion ①VMRI and 9 - IMRT planning target volume dose can meet metrological requirements. ②VMAT planning target volume dose conformal degree and uniformity is better than the 9 - IMRT. ③VMAT can reduce the dose of organs at risk,lower the number of machine hop. Therefore,it can provide better treatment and has a better organ protection.%目的:对比分析宫颈癌根治性放疗中旋转容积调强技术( VMAT)与固定野动态调强技术(9- IMRT)计量学差异,以及危及的器官剂量学差异和加速器跳数。方法选取放射科行根治性放疗的宫颈癌患者15例,对同个 CT图像进行2弧 VMAT 以及9野 IMRT 计划,对比两种放疗计划靶区剂量差异、靶区剂量适形度及均匀度,对比两种方法危及的器官剂量学差异、加速器跳数。结果 与 9- IMRT 相比,VMAT 的剂量分布均匀度(HI)及适形度(CI)更优( P<0.05)。股骨头 VMAT 的 V20 较 9- IMRT 低;直肠 VMAT 计划的直肠接受30 Gy 剂量较9野计划低;膀胱 VMAT 计划膀胱 V30明显低于 9- IMRT

  5. Testing of the stability of intensity modulated beams generated with dynamic multileaf collimation, applied to the MM50 racetrack microtron.

    Science.gov (United States)

    Dirkx, M L; Heijmen, B J

    2000-12-01

    Recently, we have published a method for the calculation of required leaf trajectories to generate optimized intensity modulated x-ray beams by means of dynamic multileaf collimation [Phys. Med. Biol. 43, 1171-1184 (1998)]. For the MM50 Racetrack Microtron it has been demonstrated that the dosimetric accuracy of this method, in combination with the dose calculation algorithm of the Cadplan 3D treatment planning system, is adequate for a clinical application (within 2% or 0.2 cm). Prior to initiating patient treatment with dynamic multileaf collimation (DMLC), tests have been performed to investigate the stability of DMLC fields generated at the MM50, (i) in time, (ii) subject to gantry rotation and (iii) in case of treatment interrupts, e.g., caused by an error detected by the treatment machine. The stability of relative dose profiles, normalized to a reference point in a relatively flat part of the modulated beam profile, was assessed from measurements with an electronic portal imaging device (EPID), with a linear diode array attached to the collimator and with film. The dose in the reference point was monitored using an ionization chamber. Tests were performed for several intensity modulated fields using 10 and 25 MV photon beams. Based on film measurements for sweeping 0.1 cm leaf gaps it was concluded that in an 80 days period the variation in leaf positioning was within 0.05 cm, without requiring any recalibration. For a uniform 10x10 cm2 field, realized dynamically by a scanning 0.4x10 cm2 slit beam, a maximum variation in slit width of 0.01 cm was derived from ionization chamber measurements, both in time and for gantry rotation. For a clinical example, the dose in the reference point reproduced within 0.2% (1 SD) over a period of 100 days. Apart from regions with very large dose gradients, variations in the relative beam profiles measured with the EPID were generally less than 1% (1 SD). For different gantry angles the dose profiles also reproduced within 1

  6. Dosimetric comparison of intensity modulated radiotherapy isocentric field plans and field in field (FIF) forward plans in the treatment of breast cancer.

    Science.gov (United States)

    Al-Rahbi, Zakiya Salem; Al Mandhari, Zahid; Ravichandran, Ramamoorthy; Al-Kindi, Fatma; Davis, Cheriyathmanjiyil Anthony; Bhasi, Saju; Satyapal, Namrata; Rajan, Balakrishnan

    2013-01-01

    The present study is aimed at comparing the planning and delivery efficiency between three-dimensional conformal radiotherapy (3D-CRT), field-in-field, forward planned, intensity modulated radiotherapy (FIF-FP-IMRT), and inverse planned intensity modulated radiotherapy (IP-IMRT). Treatment plans of 20 patients with left-sided breast cancer, 10 post-mastectomy treated to a prescribed dose of 45 Gy to the chest wall in 20 fractions, and 10 post-breast-conserving surgery to a prescribed dose of 50 Gy to the whole breast in 25 fractions, with 3D-CRT were selected. The FiF-FP-IMRT plans were created by combining two open fields with three to four segments in two tangential beam directions. Eight different beam directions were chosen to create IP-IMRT plans and were inversely optimized. The homogeneity of dose to planning target volume (PTV) and the dose delivered to heart and contralateral breast were compared among the techniques in all the 20 patients. All the three radiotherapy techniques achieved comparable radiation dose delivery to PTV-95% of the prescribed dose covering > 95% of the breast PTV. The mean volume of PTV receiving 105% (V105) of the prescribed dose was 1.7% (range 0-6.8%) for IP-IMRT, 1.9% for FP-IMRT, and 3.7% for 3D-CRT. The homogeneity and conformity indices (HI and CI) were similar for 3D-CRT and FP-IMRT, whereas the IP-IMRT plans had better conformity index at the cost of less homogeneity. The 3D-CRT and FiF-FP-IMRT plans achieved similar sparing of critical organs. The low-dose volumes (V5Gy) in the heart and lungs were larger in IP-IMRT than in the other techniques. The value of the mean dose to the ipsilateral lung was higher for IP-IMRT than the values for with FiF-FP-IMRT and 3D-CRT. In the current study, the relative volume of contralateral breast receiving low doses (0.01, 0.6, 1, and 2Gy) was significantly lower for the FiF-FP-IMRT and 3D-CRT plans than for the IP-IMRT plan. Compared with 3D-CRT and IP-IMRT, FiF-FP-IMRT proved to be a

  7. Can a peri-rectal hydrogel spaceOAR programme for prostate cancer intensity-modulated radiotherapy be successfully implemented in a regional setting?

    Science.gov (United States)

    Te Velde, Bridget L; Westhuyzen, Justin; Awad, Nader; Wood, Maree; Shakespeare, Thomas P

    2017-08-01

    The aim of this study was to investigate whether the implementation of a hydrogel spacer (SpaceOAR) programme for patients treated with 81 Gy prostate intensity-modulated radiotherapy (IMRT) in a regional setting can reduce rectal doses and toxicity. In this retrospective study, 125 patients with localised prostate cancer treated between April 2014 (programme commencement) and June 2015 were compared: 65 with SpaceOAR (inserted by five different urologists) and 60 patients treated over the same time period without SpaceOAR. Patients were treated with 81 Gy in 45Fx of IMRT over 9 weeks. Planning aims included restricting rectal doses to V40 Gy < 35%, V65 Gy < 17%, V75 Gy < 10%. Acute toxicity was assessed weekly during radiotherapy and at 12 weeks. Rectal volume parameters were all significantly lower in the SpaceOAR group, with an associated reduction in acute diarrhoea (13.8% vs 31.7%). There were no significant differences in the very low rates of acute and late faecal incontinence or proctitis, however, there was a trend towards increased haemorrhoid rate in the SpaceOAR group (11.7% vs 3.1%, P = 0.09). A SpaceOAR programme in a regional setting with urologists performing low volumes of insertions (<1 per month on average) is of clinical benefit, and was associated with significantly lower radiation doses to the rectum and lower rates of acute diarrhoea. © 2017 The Royal Australian and New Zealand College of Radiologists.

  8. SU-E-T-275: Radiobiological Evaluation of Intensity Modulated Radiotherapy Treatment for Locally Advanced Head and Neck Squamous Cell Carcinomas

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    Rekha Reddy, B.; Ravikumar, M.; Tanvir Pasha, C.R; Anil Kumar, M.R; Varatharaj, C. [Kidwai Memorial Institute of Oncology Bangalore, Karnataka (India); Pyakuryal, A [University Illinois at Chicago, Chicago, IL (United States); Narayanasamy, Ganesh [UTHSCSA, San Antonio, TX (United States)

    2014-06-01

    Purpose: To evaluate the radiobiological outcome of Intensity Modulated Radiotherapy Treatment (IMRT) for locally advanced head and neck squamous cell carcinomas using HART (Histogram Analysis in Radiation Therapy; J Appl Clin Med Phys 11(1): 137–157, 2010) program and compare with the clinical outcomes. Methods: We have treated 20 patients of stage III and IV HNSCC Oropharynx and hypopharynx with accelerated IMRT technique and concurrent chemotherapy. Delineation of tumor and normal tissues were done using Danish Head and Neck Cancer Group (DAHANCA) contouring guidelines and radiotherapy was delivered to a dose of 70Gy in 35 fractions to the primary and involved lymph nodes, 63Gy to intermediate risk areas and 56 Gy to lower risk areas, Monday to Saturday, 6 Days/week using 6 MV Photons with an expected overall treatment time of 6 weeks. The TCP and NTCP's were calculated from the dose-volume histogram (DVH) statistics using the Poisson Statistics (PS) and JT Lyman models respectively and the Resultwas correlated with clinical outcomes of the patients with mean follow up of 24 months. Results: Using HART program, the TCP (0.89± 0.01) of primary tumor and the NTCP for parotids (0.20±0.12), spinal cord (0.05±0.01), esophagus (0.30±0.2), mandible (0.35±0.21), Oral cavity (0.37±0.18), Larynx (0.30±0.15) were estimated and correlated with clinical outcome of the patients. Conclusion: Accelerated IMRT with Chemotherapy is a clinical feasible option in the treatment of locally advanced HNSCC with encouraging initial tumour response and acceptable acute toxicities. The correlation between the clinical outcomes and radiobiological model estimated parameters using HART programs are found to be satisfactory.

  9. Comparison of clinical outcomes and toxicity in endometrial cancer patients treated with adjuvant intensity-modulated radiation therapy or conventional radiotherapy.

    Science.gov (United States)

    Chen, Chien-Chih; Wang, Lily; Lu, Chien-Hsing; Lin, Jin-Ching; Jan, Jian-Sheng

    2014-12-01

    To evaluate the treatment outcomes and toxicity in endometrial cancer patients treated with hysterectomy and adjuvant intensity-modulated radiation therapy (IMRT) or conventional radiotherapy (CRT). There were 101 patients with stage IA-IIIC2 endometrial carcinoma treated with hysterectomy and adjuvant radiotherapy. In total, 36 patients received adjuvant CRT and 65 were treated with adjuvant IMRT. The endpoints were overall survival, local failure-free survival, and disease-free survival. Patients were assessed for acute toxicity weekly according to the Common Terminology Criteria for Adverse Events version 3.0. Late toxicity was evaluated according to the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. The 5-year overall survival, local failure-free survival, and disease-free survival for the CRT group and the IMRT group were 82.9% versus 93.5% (p = 0.26), 93.7% versus 89.3% (p = 0.68), and 88.0% versus 82.8% (p = 0.83), respectively. Four (11.1%) patients had Grade 3 or greater acute gastrointestinal (GI) toxicity and three (8.3%) patients had Grade 3 or greater acute genitourinary (GU) toxicity in the CRT group, whereas four (6.2%) patients had Grade 3 or greater acute GI toxicity in the IMRT group and no patient had severe GU toxicity. There was one (2.8%) patient who had Grade 3 or greater late GI toxicity and one (2.8%) patient had Grade 3 or greater late GU toxicity in the CRT group, whereas no patient had severe GI or GU toxicity in the IMRT group. Adjuvant IMRT for endometrial cancer patients had comparable clinical outcomes with CRT and had less acute and late toxicity. Copyright © 2013. Published by Elsevier B.V.

  10. Is Hemoglobin Level in Patients with Nasopharyngeal Carcinoma Still a Significant Prognostic Factor in the Era of Intensity-Modulated Radiotherapy Technology?

    Science.gov (United States)

    Guo, Shan-Shan; Tang, Lin-Quan; Chen, Qiu-Yan; Zhang, Lu; Liu, Li-Ting; Huang, Pei-Yu; Cao, Ka-Jia; Guo, Ling; Mo, Hao-Yuan; Guo, Xiang; Hong, Ming-Huang; Zeng, Mu-Sheng; Qian, Chao-Nan; Mai, Hai-Qiang

    2015-01-01

    Hemoglobin (Hb) levels are regarded as an important determinant of outcome in a number of cancers treated with radiotherapy. However, for patients treated with intensity modulated radiotherapy (IMRT), information regarding the prognostic value of hemoglobin level is scarce. A total of 650 patients with nasopharyngeal carcinoma (NPC), enrolled between May, 2005, and November, 2012, were included in this study. The prognostic significance of hemoglobin level (anemia or no-anemia) at three different time points was investigated, including before treatment, during treatment and at the last week of treatment. Univariate and multivariate analyses were conducted using the log-rank test and the Cox proportional hazards model, respectively. The 5-year OS (overall survival) rate of patients who were anemia and no-anemia before treatment were 89.1%, and 80.7% (P = 0.01), respectively. The 5-year DMFS (distant metastasis-free survival) rate of patients who were anemia and no-anemia before treatment were 88.9%, and 78.2% (P = 0.01), respectively. The 5-year OS rate of patients who were anemia and no-anemia during treatment were 91.7% and 83.3% (P = 0.004). According to multivariate analysis, the pre-treatment Hb level predicted a decreased DMFS (P = 0.007, HR = 2.555, 95% CI1.294-5.046). Besides, the mid-treatment Hb level predicted a decreased OS (P = 0.013, HR = 2.333, 95% CI1.199-4.541). Hemoglobin level is a useful prognostic factor in NPC patients receiving IMRT. It is important to control the level of hemoglobin both before and during chemoradiotherapy.

  11. Analysis of Intensity-Modulated Radiation Therapy (IMRT), Proton and 3D Conformal Radiotherapy (3D-CRT) for Reducing Perioperative Cardiopulmonary Complications in Esophageal Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Ted C.; Slater, Jerry M.; Nookala, Prashanth; Mifflin, Rachel; Grove, Roger; Ly, Anh M.; Patyal, Baldev; Slater, Jerry D.; Yang, Gary Y., E-mail: gyang@llu.edu [Department of Radiation Medicine, Loma Linda University Medical Center, 11234 Anderson Street, A875, Loma Linda, CA 92354 (United States)

    2014-12-05

    Background. While neoadjuvant concurrent chemoradiotherapy has improved outcomes for esophageal cancer patients, surgical complication rates remain high. The most frequent perioperative complications after trimodality therapy were cardiopulmonary in nature. The radiation modality utilized can be a strong mitigating factor of perioperative complications given the location of the esophagus and its proximity to the heart and lungs. The purpose of this study is to make a dosimetric comparison of Intensity-Modulated Radiation Therapy (IMRT), proton and 3D conformal radiotherapy (3D-CRT) with regard to reducing perioperative cardiopulmonary complications in esophageal cancer patients. Materials. Ten patients with esophageal cancer treated between 2010 and 2013 were evaluated in this study. All patients were simulated with contrast-enhanced CT imaging. Separate treatment plans using proton radiotherapy, IMRT, and 3D-CRT modalities were created for each patient. Dose-volume histograms were calculated and analyzed to compare plans between the three modalities. The organs at risk (OAR) being evaluated in this study are the heart, lungs, and spinal cord. To determine statistical significance, ANOVA and two-tailed paired t-tests were performed for all data parameters. Results. The proton plans showed decreased dose to various volumes of the heart and lungs in comparison to both the IMRT and 3D-CRT plans. There was no difference between the IMRT and 3D-CRT plans in dose delivered to the lung or heart. This finding was seen consistently across the parameters analyzed in this study. Conclusions. In patients receiving radiation therapy for esophageal cancer, proton plans are technically feasible while achieving adequate coverage with lower doses delivered to the lungs and cardiac structures. This may result in decreased cardiopulmonary toxicity and less morbidity to esophageal cancer patients.

  12. Baseline Serum Lactate Dehydrogenase Levels for Patients Treated With Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma: A Predictor of Poor Prognosis and Subsequent Liver Metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Guanqun; Tang Linglong; Mao Yanping; Chen Lei; Li Wenfei; Sun Ying [Department of Radiation Oncology, Cancer Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University, Guangzhou (China); Liu Lizhi; Li Li [Imaging Diagnosis and Interventional Center, Cancer Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University, Guangzhou (China); Lin Aihua [Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou (China); Ma Jun, E-mail: drjunma@hotmail.com [Department of Radiation Oncology, Cancer Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University, Guangzhou (China)

    2012-03-01

    Purpose: To evaluate the prognostic value of baseline serum lactate dehydrogenase (LDH) levels in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT). Methods and Materials: Cases of NPC (n = 465) that involved treatment with IMRT with or without chemotherapy were retrospectively analyzed. Results: The mean ({+-}SD) and median baseline serum LDH levels for this cohort were 172.77 {+-} 2.28 and 164.00 IU/L, respectively. Levels of LDH were significantly elevated in patients with locoregionally advanced disease (p = 0.016). Elevated LDH levels were identified as a prognostic factor for rates of overall survival (OS), disease-free survival (DFS), and distant metastasis-free survival (DMFS), with p values <0.001 in the univariate analysis and p < 0.001, p = 0.004, and p = 0.003, respectively, in the multivariate analysis. Correspondingly, the prognostic impact of patient LDH levels was found to be statistically significant for rates of OS, DFS, and DMFS (p = 0.028, 0.024, and 0.020, respectively). For patients who experienced subsequent liver failure after treatment, markedly higher pretreatment serum LDH levels were detected compared with patients experiencing distant metastasis events at other sites (p = 0.032). Conclusions: Elevated baseline LDH levels are associated with clinically advanced disease and are a poor prognosticator for OS, DFS, and DMFS for NPC patients. These results suggest that elevated serum levels of LDH should be considered when evaluating treatment options.

  13. CONSENSUS GUIDELINES FOR THE DELINEATION OF THE CLINICAL TARGET VOLUME FOR INTENSITY MODULATED PELVIC RADIOTHERAPY IN THE POSTOPERATIVE TREATMENT OF ENDOMETRIAL AND CERVICAL CANCER

    Science.gov (United States)

    Small, William; Mell, Loren K.; Anderson, Penny; Creutzberg, Carien; De Los Santos, Jennifer; Gaffney, David; Jhingran, Anuja; Portelance, Lorraine; Schefter, Tracey; Iyer, Revathy; Varia, Mahesh; Winter, Kathryn; Mundt, Arno J.

    2009-01-01

    PURPOSE To develop an atlas of the clinical target volumes (CTV) definitions for the post-operative radiotherapy of endometrial and cervical cancer to be utilized for planning pelvic Intensity Modulated Radiation Therapy (IMRT). METHODS AND MATERIALS The Radiation Therapy Oncology Group (RTOG) led an international collaberation of cooperative groups in development of the atlas. The groups included RTOG the Gynecologic Oncology Group (GOG), the National Cancer Institute of Canada (NCIC), the European Society of Therapeutic Radiology and Oncology (ESTRO), and the American College of Radiology Imaging Network (ACRIN). Members of the group were asked by questionnaire to define areas that were to be included in the CTV and were asked to outline theses areas on individual Computed Tomography (CT) images. The initial formulation of the group began in late 2004 and culminated with a formal consensus conference in June of 2005. RESULTS The committee achieved a consensus CTV definition for the post-operative therapy of endometrial and cervical cancer. The CTV should include the common, external, and internal iliac lymph node regions. The upper 3.0 cm of vagina and paravaginal soft tissue lateral to the vagina should also be included. For patients with cervical cancer, or endometrial cancer with cervical stromal invasion, it is also recommended that the CTV include the presacral lymph node-region. CONCLUSIONS This manuscript serves as an international template for the definition of the CTV for the post-operative IMRT of endometrial and cervical cancer. PMID:18037584

  14. Dental extractions for preradiation dental clearance and incidence of osteoradionecrosis in patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy.

    Science.gov (United States)

    See Toh, Yoong L; Soong, Yoke L; Chim, Yi X; Tan, Li T; Lye, Weng K; Teoh, Khim H

    2017-09-01

    The aims of the present retrospective study were to evaluate the outcomes of dental extractions in nasopharyngeal carcinoma patients who had undergone dental clearance pre- and post-radiotherapy (RT) with intensity-modulated RT, and to report on the incidence and timing of osteoradionecrosis (ORN) in these patients. A total of 231 patients were seen pre-, mid-, and postradiation therapy. Information on patient demographics, smoking history, staging, treatment modalities, dental extraction indications, and number and site of dental extractions was gathered. Wilcoxon two-sample tests and Fisher's exact test were used to test the association between groups for patient variables. The mean number of teeth removed was 4.1 teeth per patient. A total of 334 (35.2%) teeth were removed for periodontal reasons, 322 (34.03%) were removed prophylactically, and the remaining teeth were removed because of deep caries, retained roots, partial impaction, endodontic lesions, and prosthodontic reasons. Patients had an average of 19.6 teeth remaining after dental clearance, and only 97 (42%) required prosthetic intervention. The statistical analysis showed that there was no correlation between dental extractions pre- or post-RT and the development of ORN. No specific parameter was directly associated with dental extractions, although smoking and increased number of teeth removed preradiation seemed to be prevalent in patients who developed ORN. © 2017 John Wiley & Sons Australia, Ltd.

  15. Outcomes of Induction Chemotherapy Plus Intensity-Modulated Radiotherapy (IMRT Versus IMRT Plus Concurrent Chemotherapy for Locoregionally Advanced Nasopharyngeal Carcinoma: A Propensity Matched Study

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    Pu-Yun OuYang

    2016-08-01

    Full Text Available PURPOSE: It deserves investigation whether induction chemotherapy (IC followed by intensity-modulated radiotherapy (IMRT is inferior to the current standard of IMRT plus concurrent chemotherapy (CC in locoregionally advanced nasopharyngeal carcinoma. METHODS: Patients who received IC (94 patients or CC (302 patients plus IMRT at our center between March 2003 and November 2012 were retrospectively analyzed. Propensity-score matching method was used to match patients in both arms at equal ratio. Failure-free survival (FFS, overall survival (OS, distant metastasis–free survival (DMFS, and locoregional relapse–free survival (LRFS were assessed with Kaplan-Meier method, log-rank test, and Cox regression. RESULTS: In the original cohort of 396 patients, IC plus IMRT resulted in similar FFS (P = .565, OS (P = .334, DMFS (P = .854, and LRFS (P = .999 to IMRT plus CC. In the propensity-matched cohort of 188 patients, no significant survival differences were observed between the two treatment approaches (3-year FFS 80.3% vs 81.0%, P = .590; OS 93.4% vs 92.1%, P = .808; DMFS 85.9% vs 87.7%, P = .275; and LRFS 93.1% vs 92.0%, P = .763. Adjusting for the known prognostic factors in multivariate analysis, IC plus IMRT did not cause higher risk of treatment failure, death, distant metastasis, or locoregional relapse. CONCLUSIONS: IC plus IMRT appeared to achieve comparable survival to IMRT plus CC in locoregionally advanced nasopharyngeal carcinoma. Further investigations were warranted.

  16. Investigation of the feasibility of elective irradiation to neck level Ib using intensity-modulated radiotherapy for patients with nasopharyngeal carcinoma: a retrospective analysis.

    Science.gov (United States)

    Zhang, Fan; Cheng, Yi-Kan; Li, Wen-Fei; Guo, Rui; Chen, Lei; Sun, Ying; Mao, Yan-Ping; Zhou, Guan-Qun; Liu, Xu; Liu, Li-Zhi; Lin, Ai-Hua; Tang, Ling-Long; Ma, Jun

    2015-10-15

    To assess the feasibility of elective neck irradiation to level Ib in nasopharyngeal carcinoma (NPC) using intensity-modulated radiation therapy (IMRT). We retrospectively analyzed 1438 patients with newly-diagnosed, non-metastatic and biopsy-proven NPC treated with IMRT. Greatest dimension of level IIa LNs (DLN-IIa) ≥ 20 mm and/or level IIa LNs with extracapsular spread (ES), oropharynx involvement and positive bilateral cervical lymph nodes (CLNs) were independently significantly associated with metastasis to level Ib LN at diagnosis. No recurrence at level Ib was observed in the 904 patients without these characteristics (median follow-up, 38.7 months; range, 1.3-57.8 months), these patients were classified as low risk. Level Ib irradiation was not an independent risk factor for locoregional failure-free survival, distant failure-free survival, failure-free survival or overall survival in low risk patients. The frequency of grade ≥ 2 subjective xerostomia at 12 months after radiotherapy was not significantly different between low risk patients who received level Ib-sparing, unilateral level Ib-covering or bilateral level Ib-covering IMRT. Level Ib-sparing IMRT should be safe and feasible for patients without a DLN-IIa ≥ 20 mm and/or level IIa LNs with ES, positive bilateral CLNs or oropharynx involvement at diagnosis. Further investigations based on specific criteria for dose constraints for the submandibular glands are warranted to confirm the benefit of elective level Ib irradiation.

  17. Selective omission of level V nodal coverage for patients with oropharyngeal cancer: Clinical validation of intensity-modulated radiotherapy experience and dosimetric significance.

    Science.gov (United States)

    Mohindra, Pranshu; Urban, Erich; Pagan, Jonathan D; Geye, Heather M; Patel, Vatsal B; Bayliss, R Adam A; Bender, Edward T; Harari, Paul M

    2016-04-01

    We sought to validate the consensus recommendation and assess dosimetric significance of selective omission of nodal level V from intensity-modulated radiotherapy (IMRT) clinical target volume (CTV) for oropharyngeal cancer. IMRT plans and clinical outcomes for 112 patients with oropharyngeal cancer (nodal classification N0-N2b) were analyzed for coverage of ipsilateral and contralateral nodal level V. Additionally, new IMRT plans were generated in 6 randomly selected patients to assess its dosimetric impact. With median follow-up of 3.4 years, there were no failures identified in nodal level V with or without nodal level V omission. Upon dosimetric evaluation, significant reduction in integral dose, V10 Gy , V20 Gy , V30 Gy , V40 Gy , and V50 Gy was observed by excluding unilateral and bilateral level V from the CTV. We clinically validate the consensus recommendation for selective omission of level V nodal coverage in IMRT planning of patients with oropharyngeal cancer and demonstrate significant dosimetric advantages. © 2016 Wiley Periodicals, Inc.

  18. Reirradiation of head and neck cancer in the era of intensity-modulated radiotherapy: Patient selection, practical aspects, and current evidence

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    Kim, Yeon Sil [Dept. of Radiation Oncology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul(Korea, Republic of)

    2017-03-15

    Locoregional failure is the most frequent pattern of failure in locally advanced head and neck cancer patients and it leads to death in most of the patients. Second primary tumors occurring in the other head and neck region reach up to almost 40% of long-term survivors. Recommended and preferred retreatment option in operable patients is salvage surgical resection, reporting a 5-year overall survival of up to 40%. However, because of tumor location, extent, and underlying comorbidities, salvage surgery is often limited and compromised by incomplete resection. Reirradiation with or without combined chemotherapy is an appropriate option for unresectable recurrence. Reirradiation is carefully considered with a case-by-case basis. Reirradiation protocol enrollment is highly encouraged prior to committing patient to an aggressive therapy. Radiation doses greater than 60 Gy are usually recommended for successful salvage. Despite recent technical improvement in intensity-modulated radiotherapy (IMRT), the use of concurrent chemotherapy, and the emergence of molecularly targeted agents, careful patient selection remain as the most paramount factor in reirradiation. Tumors that recur or persist despite aggressive prior chemoradiation therapy imply the presence of chemoradio-resistant clonogens. Treatment protocols that combine novel targeted radiosensitizing agents with conformal high precision radiation are required to overcome the resistance while minimizing toxicity. Recent large number of data showed that IMRT may provide better locoregional control with acceptable acute or chronic morbidities. However, additional prospective studies are required before a definitive conclusion can be drawn on safety and effectiveness of IMRT.

  19. Dose-volume relationships for moderate or severe neck muscle atrophy after intensity-modulated radiotherapy in patients with nasopharyngeal carcinoma

    Science.gov (United States)

    Zhang, Lu-Lu; Wang, Xiao-Ju; Zhou, Guan-Qun; Tang, Ling-Long; Lin, Ai-Hua; Ma, Jun; Sun, Ying

    2015-01-01

    This study aimed to identify the dosimetric parameters and radiation dose tolerances associated with moderate or severe sternocleidomastoid muscle (SCM) atrophy after intensity-modulated radiotherapy (IMRT) in nasopharyngeal carcinoma (NPC). We retrospectively analysed 138 patients treated with IMRT between 2011 and 2012 for whom IMRT treatment plans and pretreatment and 3-year post-IMRT MRI scans were available. The association between mean dose (Dmean), maximum dose (Dmax), VX (% SCM volume that received more than X Gy), DX (dose to X% of the SCM volume) at X values of 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 and SCM atrophy at 3 years after IMRT were analyzed. All dosimetric parameters, except V40, V50 and V80, were significantly associated with moderate or severe SCM atrophy. Multivariate analysis showed that V65 was an independent predictor of moderate or severe SCM atrophy (P < 0.001). Receiver operating characteristic (ROC) curve indicated a V65 of 21.47% (area under ROC curves, 0.732; P < 0.001) was the tolerated dose for moderate or severe SCM atrophy. We suggest a limit of 21.47% for V65 to optimize NPC treatment planning, whilst minimizing the risk of moderate or severe SCM atrophy. PMID:26678599

  20. Intensity-modulated radiation therapy for anal carcinoma; Radiotherapie conformationnelle avec modulation d'intensite des cancers de l'anus

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    Peiffert, D.; Moreau-Claeys, M.V.; Tournier-Rangeard, L.; Huger, S.; Marchesi, V. [Departement de radiotherapie, centre Alexis-Vautrin, 6, avenue de Bourgogne, 54511 Vandoeuvre-les-Nancy cedex (France)

    2011-10-15

    Anal canal carcinoma are highly curable by irradiation, combined with chemotherapy in locally advanced disease, with preservation of sphincter function. The clinical target volume for the nodes is extended, often including the inguinal nodes, which is not usual for other pelvic tumours. Acute and late effects are correlated with the volume and dose delivered to organs at risk, i. e. small bowel, bladder and increased by concomitant chemotherapy. Intensity modulated irradiation (IMRT) makes it possible to optimize the dose distribution in this 'complex U shaped' volume, while maintaining the dose distribution for the target volumes. The conversion from conformal irradiation to IMRT necessitates good knowledge of the definition and skills to delineate target volumes and organs at risk, including new volumes needed to optimize the dose distribution. Dosimetric and clinical benefits of IMRT are described, based on early descriptions and evidence-based publication. The growing development of IMRT in anal canal radiotherapy must be encouraged, and long-term benefits should be soon published. Radiation oncologists should precisely learn IMRT recommendations before starting the technique, and evaluate its early and late results for adverse effects, but also for long-term tumour control. (authors)

  1. The Evolution of and Risk Factors for Neck Muscle Atrophy and Weakness in Nasopharyngeal Carcinoma Treated With Intensity-Modulated Radiotherapy

    Science.gov (United States)

    Zhang, Lu-Lu; Mao, Yan-Ping; Zhou, Guan-Qun; Tang, Ling-Long; Qi, Zhen-Yu; Lin, Li; Yao, Ji-Jin; Ma, Jun; Lin, Ai-Hua; Sun, Ying

    2015-01-01

    Abstract The aim of this study was to investigate the evolution of sternocleidomastoid muscle (SCM) atrophy in nasopharyngeal carcinoma (NPC) patients following intensity-modulated radiotherapy (IMRT), and the relationship between SCM atrophy and neck weakness. Data were retrospectively analyzed from 223 biopsy-proven NPC patients with no distant metastasis who underwent IMRT with or without chemotherapy. The volume of SCM was measured on pretreatment magnetic resonance imaging (MRI), and MRIs were conducted 1, 2, and 3 years after the completion of IMRT. Change in SCM volume was calculated and classified using the late effects of normal tissues–subjective, objective, management, and analytic system. The grade of neck muscle weakness, classified by the Common Terminology Criteria for Adverse Events V 3.0, was measured 3 years after the completion of IMRT. The average SCM atrophy ratio was −10.97%, −18.65%, and −22.25% at 1, 2, and 3 years postirradiation, respectively. Multivariate analysis indicated N stage and the length of time after IMRT were independent prognostic variables. There were significant associations between the degree of SCM atrophy and neck weakness. Radical IMRT can cause significant SCM atrophy in NPC patients. A more advanced N stage was associated with more severe SCM atrophy, but no difference was observed between N2 and N3. SCM atrophy progresses over time during the 3 years following IMRT. Grade of SCM atrophy is significantly associated with neck weakness. PMID:26252307

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

    Science.gov (United States)

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

    2013-11-04

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

  3. The Evolution of and Risk Factors for Neck Muscle Atrophy and Weakness in Nasopharyngeal Carcinoma Treated With Intensity-Modulated Radiotherapy: A Retrospective Study in an Endemic Area.

    Science.gov (United States)

    Zhang, Lu-Lu; Mao, Yan-Ping; Zhou, Guan-Qun; Tang, Ling-Long; Qi, Zhen-Yu; Lin, Li; Yao, Ji-Jin; Ma, Jun; Lin, Ai-Hua; Sun, Ying

    2015-08-01

    The aim of this study was to investigate the evolution of sternocleidomastoid muscle (SCM) atrophy in nasopharyngeal carcinoma (NPC) patients following intensity-modulated radiotherapy (IMRT), and the relationship between SCM atrophy and neck weakness.Data were retrospectively analyzed from 223 biopsy-proven NPC patients with no distant metastasis who underwent IMRT with or without chemotherapy. The volume of SCM was measured on pretreatment magnetic resonance imaging (MRI), and MRIs were conducted 1, 2, and 3 years after the completion of IMRT. Change in SCM volume was calculated and classified using the late effects of normal tissues-subjective, objective, management, and analytic system. The grade of neck muscle weakness, classified by the Common Terminology Criteria for Adverse Events V 3.0, was measured 3 years after the completion of IMRT.The average SCM atrophy ratio was -10.97%, -18.65%, and -22.25% at 1, 2, and 3 years postirradiation, respectively. Multivariate analysis indicated N stage and the length of time after IMRT were independent prognostic variables. There were significant associations between the degree of SCM atrophy and neck weakness.Radical IMRT can cause significant SCM atrophy in NPC patients. A more advanced N stage was associated with more severe SCM atrophy, but no difference was observed between N2 and N3. SCM atrophy progresses over time during the 3 years following IMRT. Grade of SCM atrophy is significantly associated with neck weakness.

  4. Rapid Arc, helical tomotherapy, sliding window intensity modulated radiotherapy and three dimensional conformal radiation for localized prostate cancer: A dosimetric comparison

    Directory of Open Access Journals (Sweden)

    Rajesh A Kinhikar

    2014-01-01

    Full Text Available Objective: The objective of this study was to investigate the potential role of RapidArc (RA compared with helical tomotherapy (HT, sliding window intensity modulated radiotherapy (SW IMRT and three-dimensional conformal radiation therapy (3D CRT for localized prostate cancer. Materials and Methods: Prescription doses ranged from 60 Gy to planning target volume (PTV and 66.25 Gy for clinical target volume prostate (CTV-P over 25-30 fractions. PTV and CTV-P coverage were evaluated by conformity index (CI and homogeneity index (HI. Organ sparing comparison was done with mean doses to rectum and bladder. Results: CI 95 were 1.0 ± 0.01 (RA, 0.99 ± 0.01 (HT, 0.97 ± 0.02 (IMRT, 0.98 ± 0.02 (3D CRT for PTV and 1.0 ± 0.00 (RA, HT, SW IMRT and 3D CRT for CTV-P. HI was 0.11 ± 0.03 (RA, 0.16 ± 0.08 (HT, 0.12 ± 0.03 (IMRT, 0.06 ± 0.01 (3D CRT for PTV and 0.03 ± 0.00 (RA, 0.05 ± 0.01 (HT, 0.03 ± 0.01 (SW IMRT and 3D CRT for CTV-P. Mean dose to bladder were 23.68 ± 13.23 Gy (RA, 24.55 ± 12.51 Gy (HT, 19.82 ± 11.61 Gy (IMRT and 23.56 ± 12.81 Gy (3D CRT, whereas mean dose to rectum was 36.85 ± 12.92 Gy (RA, 33.18 ± 11.12 Gy (HT, IMRT and 38.67 ± 12.84 Gy (3D CRT. Conclusion: All studied intensity-modulated techniques yield treatment plans of significantly improved quality when compared with 3D CRT, with HT providing best organs at risk sparing and RA being the most efficient treatment option, reducing treatment time to 1.45-3.7 min and monitor unit to <400 for a 2 Gy fraction.

  5. Comparison of Three-Dimensional (3D) Conformal Proton Radiotherapy (RT), 3D Conformal Photon RT, and Intensity-Modulated RT for Retroperitoneal and Intra-Abdominal Sarcomas

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, Erika L. [Department of Radiation Oncology, University of Florida, Gainesville, Florida (United States); Indelicato, Daniel J., E-mail: dindelicato@floridaproton.org [Department of Radiation Oncology, University of Florida, Gainesville, Florida (United States); University of Florida Proton Therapy Institute, Jacksonville, Florida (United States); Louis, Debbie; Flampouri, Stella; Li, Zuofeng [University of Florida Proton Therapy Institute, Jacksonville, Florida (United States); Morris, Christopher G.; Paryani, Nitesh [Department of Radiation Oncology, University of Florida, Gainesville, Florida (United States); Slopsema, Roelf [University of Florida Proton Therapy Institute, Jacksonville, Florida (United States)

    2012-08-01

    Purpose: To compare three-dimensional conformal proton radiotherapy (3DCPT), intensity-modulated photon radiotherapy (IMRT), and 3D conformal photon radiotherapy (3DCRT) to predict the optimal RT technique for retroperitoneal sarcomas. Methods and Materials: 3DCRT, IMRT, and 3DCPT plans were created for treating eight patients with retroperitoneal or intra-abdominal sarcomas. The clinical target volume (CTV) included the gross tumor plus a 2-cm margin, limited by bone and intact fascial planes. For photon plans, the planning target volume (PTV) included a uniform expansion of 5 mm. For the proton plans, the PTV was nonuniform and beam-specific. The prescription dose was 50.4 Gy/Cobalt gray equivalent CGE. Plans were normalized so that >95% of the CTV received 100% of the dose. Results: The CTV was covered adequately by all techniques. The median conformity index was 0.69 for 3DCPT, 0.75 for IMRT, and 0.51 for 3DCRT. The median inhomogeneity coefficient was 0.062 for 3DCPT, 0.066 for IMRT, and 0.073 for 3DCRT. The bowel median volume receiving 15 Gy (V15) was 16.4% for 3DCPT, 52.2% for IMRT, and 66.1% for 3DCRT. The bowel median V45 was 6.3% for 3DCPT, 4.7% for IMRT, and 15.6% for 3DCRT. The median ipsilateral mean kidney dose was 22.5 CGE for 3DCPT, 34.1 Gy for IMRT, and 37.8 Gy for 3DCRT. The median contralateral mean kidney dose was 0 CGE for 3DCPT, 6.4 Gy for IMRT, and 11 Gy for 3DCRT. The median contralateral kidney V5 was 0% for 3DCPT, 49.9% for IMRT, and 99.7% for 3DCRT. Regardless of technique, the median mean liver dose was <30 Gy, and the median cord V50 was 0%. The median integral dose was 126 J for 3DCPT, 400 J for IMRT, and 432 J for 3DCRT. Conclusions: IMRT and 3DCPT result in plans that are more conformal and homogenous than 3DCRT. Based on Quantitative Analysis of Normal Tissue Effects in Clinic benchmarks, the dosimetric advantage of proton therapy may be less gastrointestinal and genitourinary toxicity.

  6. Long-term outcomes from dose-escalated image-guided intensity-modulated radiotherapy with androgen deprivation: encouraging results for intermediate- and high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Wilcox SW

    2014-08-01

    Full Text Available Shea W Wilcox,1,4 Noel J Aherne,2,4 Linus C Benjamin,1 Bosco Wu,1 Thomaz de Campos Silva,3 Craig S McLachlan,4 Michael J McKay,3,5 Andrew J Last,1 Thomas P Shakespeare1–4 1North Coast Cancer Institute, Port Macquarie, NSW, Australia; 2North Coast Cancer Institute, Coffs Harbour, NSW, Australia; 3North Coast Cancer Institute, Lismore, NSW, Australia; 4The University of New South Wales, Rural Clinical School, Sydney, NSW, Australia; 5The University of Sydney, Sydney, NSW, Australia Purpose: Dose-escalated (DE radiotherapy in the setting of localized prostate cancer has been shown to improve biochemical disease-free survival (bDFS in several studies. In the same group of patients, androgen deprivation therapy (ADT has been shown to confer a survival benefit when combined with radiotherapy doses of up to 70 Gy; however, there is currently little long-term data on patients who have received high-dose intensity-modulated radiotherapy (IMRT with ADT. We report the long-term outcomes in a large cohort of patients treated with the combination of DE image-guided IMRT (IG-IMRT and ADT. Methods and materials: Patients with localized prostate cancer were identified from a centralized database across an integrated cancer center. All patients received DE IG-IMRT, combined with ADT, and had a minimum follow up of 12 months post-radiotherapy. All relapse and toxicity data were collected prospectively. Actuarial bDFS, metastasis-free survival, prostate cancer-specific survival, and multivariate analyses were calculated using the SPSS v20.0 statistical package. Results: Seven hundred and eighty-two eligible patients were identified with a median follow up of 46 months. Overall, 4.3% of patients relapsed, 2.0% developed distant metastases, and 0.6% died from metastatic prostate cancer. At 5-years, bDFS was 88%, metastasis-free survival was 95%, and prostate cancer-specific survival was 98%. Five-year grade 2 genitourinary and gastrointestinal toxicity was 2

  7. Volumetric intensity-modulated arc therapy vs. 3-dimensional conformal radiotherapy for primary chemoradiotherapy of anal carcinoma. Effects on treatment-related side effects and survival

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Hanne Elisabeth; Droege, Leif Hendrik; Hennies, Steffen; Herrmann, Markus Karl; Wolff, Hendrik Andreas [University Medical Center Goettingen, Dept. of Radiotherapy and Radiooncology, Goettingen (Germany); Gaedcke, Jochen [University Medical Center Goettingen, Dept. of General Surgery, Goettingen (Germany)

    2015-11-15

    Primary chemoradiotherapy (CRT) is the standard treatment for locally advanced anal carcinoma. This study compared volumetric intensity-modulated arc therapy (VMAT) to 3-dimensional conformal radiotherapy (3DCRT) in terms of treatment-related side effects and survival. From 1992-2014, 103 consecutive patients with anal carcinoma UICC stage I-III were treated. Concomitant CRT consisted of whole pelvic irradiation, including the iliac and inguinal lymph nodes, with 50.4 Gy (1.8 Gy per fractions) by VMAT (n = 17) or 3DCRT (n = 86) as well as two cycles of 5-fluorouracil and mitomycin C. Acute organ and hematological toxicity were assessed according to the Common Terminology Criteria (CTC) for Adverse Events version 3.0. Side effects ≥ grade 3 were scored as high-grade toxicity. High-grade acute organ toxicity CTC ≥ 3 (P < 0.05), especially proctitis (P = 0.03), was significantly reduced in VMAT patients. The 2-year locoregional control (LRC) and disease-free survival (DFS) were both 100 % for VMAT patients compared with 80 and 73 % for 3DCRT patients. VMAT was shown to be a feasible technique, achieving significantly lower rates of acute organ toxicity and promising results for LRC and DFS. Future investigations will aim at assessing the advantages of VMAT with respect to late toxicity and survival after a prolonged follow-up time. (orig.) [German] Die primaere Radiochemotherapie (RCT) gilt als Standardtherapie fuer lokal fortgeschrittene Analkarzinome. In dieser Studie wurde die volumetrisch modulierte Rotationstherapie (''volumetric intensity-modulated arc therapy'', VMAT) mit der klassischen dreidimensionalen konformalen Radiotherapie (3DCRT) hinsichtlich therapieassoziierter Nebenwirkungen und Ueberleben verglichen. Von 1992-2014 wurden 103 aufeinanderfolgende Patienten mit einem Analkarzinom im UICC-Stadium I-III behandelt. Die kombinierte RCT bestand aus der Bestrahlung des gesamten Beckens inklusive der iliakalen und der inguinalen

  8. 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.

  9. Dosimetric comparison of intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in total scalp irradiation: a single institutional experience

    Energy Technology Data Exchange (ETDEWEB)

    Ostheimer, Christian; Huebsch, Patrick; Janich, Martin; Gerlach, Reinhard; Vordermark, Dirk [Dept. of Radiation Oncology, Faculty of Medicine, Martin Luther University Halle-Wittenberg, Halle (Germany)

    2016-12-15

    Total scalp irradiation (TSI) is a rare but challenging indication. We previously reported that non-coplanar intensity-modulated radiotherapy (IMRT) was superior to coplanar IMRT in organ-at-risk (OAR) protection and target dose distribution. This consecutive treatment planning study compared IMRT with volumetric-modulated arc therapy (VMAT). A retrospective treatment plan databank search was performed and 5 patient cases were randomly selected. Cranial imaging was restored from the initial planning computed tomography (CT) and target volumes and OAR were redelineated. For each patients, three treatment plans were calculated (coplanar/non-coplanar IMRT, VMAT; prescribed dose 50 Gy, single dose 2 Gy). Conformity, homogeneity and dose volume histograms were used for plan. VMAT featured the lowest monitor units and the sharpest dose gradient (1.6 Gy/mm). Planning target volume (PTV) coverage and homogeneity was better in VMAT (coverage, 0.95; homogeneity index [HI], 0.118) compared to IMRT (coverage, 0.94; HI, 0.119) but coplanar IMRT produced the most conformal plans (conformity index [CI], 0.43). Minimum PTV dose range was 66.8% –88.4% in coplanar, 77.5%–88.2% in non-coplanar IMRT and 82.8%–90.3% in VMAT. Mean dose to the brain, brain stem, optic system (maximum dose) and lenses were 18.6, 13.2, 9.1, and 5.2 Gy for VMAT, 21.9, 13.4, 14.5, and 6.3 Gy for non-coplanar and 22.8, 16.5, 11.5, and 5.9 Gy for coplanar IMRT. Maximum optic chiasm dose was 7.7, 8.4, and 11.1 Gy (non-coplanar IMRT, VMAT, and coplanar IMRT). Target coverage, homogeneity and OAR protection, was slightly superior in VMAT plans which also produced the sharpest dose gradient towards healthy tissue.

  10. Intensity modulated radiotherapy (IMRT in the treatment of children and Adolescents - a single institution's experience and a review of the literature

    Directory of Open Access Journals (Sweden)

    Huber Peter

    2009-09-01

    Full Text Available Abstract Background While IMRT is widely used in treating complex oncological cases in adults, it is not commonly used in pediatric radiation oncology for a variety of reasons. This report evaluates our 9 year experience using stereotactic-guided, inverse planned intensity-modulated radiotherapy (IMRT in children and adolescents in the context of the current literature. Methods Between 1999 and 2008 thirty-one children and adolescents with a mean age of 14.2 years (1.5 - 20.5 were treated with IMRT in our department. This heterogeneous group of patients consisted of 20 different tumor entities, with Ewing's sarcoma being the largest (5 patients, followed by juvenile nasopharyngeal fibroma, esthesioneuroblastoma and rhabdomyosarcoma (3 patients each. In addition a review of the available literature reporting on technology, quality, toxicity, outcome and concerns of IMRT was performed. Results With IMRT individualized dose distributions and excellent sparing of organs at risk were obtained in the most challenging cases. This was achieved at the cost of an increased volume of normal tissue receiving low radiation doses. Local control was achieved in 21 patients. 5 patients died due to progressive distant metastases. No severe acute or chronic toxicity was observed. Conclusion IMRT in the treatment of children and adolescents is feasible and was applied safely within the last 9 years at our institution. Several reports in literature show the excellent possibilities of IMRT in selective sparing of organs at risk and achieving local control. In selected cases the quality of IMRT plans increases the therapeutic ratio and outweighs the risk of potentially increased rates of secondary malignancies by the augmented low dose exposure.

  11. 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.

  12. Prospective Preference Assessment of Patients' Willingness to Participate in a Randomized Controlled Trial of Intensity-Modulated Radiotherapy Versus Proton Therapy for Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Anand [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Efstathiou, Jason A.; Paly, Jonathan J. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Halpern, Scott D. [Department of Medicine, University of Pennsylvania, Philadelphia, PA (United States); Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA (United States); Center for Bioethics, University of Pennsylvania, Philadelphia, PA (United States); Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA (United States); Bruner, Deborah W. [Winship Cancer Institute, Emory University, Atlanta, GA (United States); Christodouleas, John P. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Coen, John J. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Deville, Curtiland; Vapiwala, Neha [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Shipley, William U.; Zietman, Anthony L. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Hahn, Stephen M. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Bekelman, Justin E., E-mail: bekelman@uphs.upenn.edu [Department of Radiation Oncology, 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 investigate patients' willingness to participate (WTP) in a randomized controlled trial (RCT) comparing intensity-modulated radiotherapy (IMRT) with proton beam therapy (PBT) for prostate cancer (PCa). Methods and Materials: We undertook a qualitative research study in which we prospectively enrolled patients with clinically localized PCa. We used purposive sampling to ensure a diverse sample based on age, race, travel distance, and physician. Patients participated in a semi-structured interview in which they reviewed a description of a hypothetical RCT, were asked open-ended and focused follow-up questions regarding their motivations for and concerns about enrollment, and completed a questionnaire assessing characteristics such as demographics and prior knowledge of IMRT or PBT. Patients' stated WTP was assessed using a 6-point Likert scale. Results: Forty-six eligible patients (33 white, 13 black) were enrolled from the practices of eight physicians. We identified 21 factors that impacted patients' WTP, which largely centered on five major themes: altruism/desire to compare treatments, randomization, deference to physician opinion, financial incentives, and time demands/scheduling. Most patients (27 of 46, 59%) stated they would either 'definitely' or 'probably' participate. Seventeen percent (8 of 46) stated they would 'definitely not' or 'probably not' enroll, most of whom (6 of 8) preferred PBT before their physician visit. Conclusions: A substantial proportion of patients indicated high WTP in a RCT comparing IMRT and PBT for PCa.

  13. Postoperative Intensity-Modulated Radiotherapy for Squamous Cell Carcinoma of the External Auditory Canal and Middle Ear: Treatment Outcomes, Marginal Misses, and Perspective on Target Delineation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wan-Yu [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Kuo, Sung-Hsin [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan (China); Chen, Yu-Hsuan; Lu, Szu-Huai; Tsai, Chiao-Ling [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chia-Hsien Cheng, Jason [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan (China); Graduate Institute of Oncology, National Taiwan University College of Medicine, Taipei, Taiwan (China); Hong, Ruey-Long [Division of Medical Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Ya-Fang [Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan (China); Hsu, Chuan-Jen; Lin, Kai-Nan; Ko, Jenq-Yuh; Lou, Pei-Jen; Wang, Cheng-Ping [Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan (China); Chong, Fok-Ching [Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Wang, Chun-Wei, E-mail: cwwang@ntuh.gov.tw [Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China)

    2012-03-15

    Purpose: To report outcomes of the rare disease of squamous cell carcinoma (SCC) of the external auditory canal (EAC) and middle ear treated with surgery and postoperative intensity-modulated radiotherapy (IMRT). Failure patterns related to spatial dose distribution were also analyzed to provide insight into target delineation. Methods and Materials: A retrospective review was conducted of the records of 11 consecutive patients with SCC of the EAC and middle ear who were treated with curative surgery and postoperative IMRT at one institution between January 2007 and February 2010. The prescribed IMRT dose was 60 to 66 Gy at 2 Gy per fraction. Three patients also received concurrent cisplatin-based chemotherapy, and 1 patient received concurrent oral tegafur/uracil. The median follow-up time was 19 months (range, 6-33 months). Results: Four patients had locoregional recurrence, yielding an estimated 2-year locoregional control rate of 70.7%. Among them, 1 patient had persistent disease after treatment, and 3 had marginal recurrence. Distant metastasis occurred in 1 patient after extensive locoregional recurrence, yielding an estimated 2-year distant control rate of 85.7%. The estimated 2-year overall survival was 67.5%. The three cases of marginal recurrence were near the preauricular space and glenoid fossa of the temporomandibular joint, adjacent to the apex of the ear canal and glenoid fossa of the temporomandibular joint, and in the postauricular subcutaneous area and ipsilateral parotid nodes, respectively. Conclusions: Marginal misses should be recognized to improve target delineation. When treating SCC of the EAC and middle ear, care should be taken to cover the glenoid fossa of the temporomandibular joint and periauricular soft tissue. Elective ipsilateral parotid irradiation should be considered. The treatment planning procedure should also be refined to balance subcutaneous soft-tissue dosimetry and toxicity.

  14. Long-term outcome and late toxicities of simultaneous integrated boost-intensity modulated radiotherapy in pediatric and adolescent nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Chang-Juan Tao; Ai-Hua Lin; Jun Ma; Ying Sun; Xu Liu; Ling-Long Tang; Yan-Ping Mao; Lei Chen; Wen-Fei Li; Xiao-Li Yu; Li-Zhi Liu; Rong Zhang

    2013-01-01

    The application of simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) in pediatric and adolescent nasopharyngeal carcinoma (NPC) is underevaluated. This study aimed to evaluate long-term outcome and late toxicities in pediatric and adolescent NPC after SIB-IMRT combined with chemotherapy. Thirty-four patients (aged 8-20 years) with histologically proven, non-disseminated NPC treated with SIB-IMRT were enrol ed in this retrospective study. The disease stage distribution was as fol ows:stage I, 1 (2.9%);stage III, 14 (41.2%);and stage IV, 19 (55.9%). Al patients underwent SIB-IMRT and 30 patients also underwent cisplatin-based chemotherapy. The prescribed dose of IMRT was 64-68 Gy in 29-31 fractions to the nasopharyngeal gross target volume. Within the median fol ow-up of 52 months (range, 9-111 months), 1 patient (2.9%) experienced local recurrence and 4 (11.8%) developed distant metastasis (to the lung in 3 cases and to multiple organs in 1 case). Four patients (11.8%) died due to recurrence or metastasis. The 5-year locoregional relapse-free survival, distant metastasis-free survival, disease-free survival, and overal survival rates were 97.1%, 88.2%, 85.3%, and 88.2%, respectively. The most common acute toxicities were grades 3-4 hematologic toxicities and stomatitis. Of the 24 patients who survived for more than 2 years, 16 (66.7%) and 15 (62.5%) developed grades 1-2 xerostomia and ototoxicity, respectively. Two patients (8.3%) developed grade 3 ototoxicity; no grade 4 toxicities were observed. SIB-IMRT combined with chemotherapy achieves excellent long-term locoregional control in pediatric and adolescent NPC, with mild incidence of late toxicities. Distant metastasis is the predominant mode of failure.

  15. Changes of plasma cytokines and chemokines expression level in nasopharyngeal carcinoma patients after treatment with definitive intensity-modulated radiotherapy (IMRT).

    Science.gov (United States)

    Jin, Ya-Bin; Zhang, Guo-Yi; Lin, Kai-Rong; Chen, Xiang-Ping; Cui, Jin-Huan; Wang, Yue-Jian; Luo, Wei

    2017-01-01

    Potential clinical application values of certain cytokines and chemokines that participate in the process of tumor growth, invasion, and metastasis have been reported. However, there still lack of biomarkers for a great many of malignancy. This study identified cytokines or chemokines involved in the occurrence and development of nasopharyngeal carcinoma (NPC), which might be a biomarker for noninvasive early diagnosis. The plasma levels of 19 cytokines and chemokines were detected by the luminex liquid array-based multiplexed immunoassays in 39 NPC patients before and after treatment by definitive intensity-modulated radiotherapy (IMRT). Plasma levels of almost all of the 19 cytokines and chemokines in NPC patients were higher than healthy controls, while only IFN-γ, IL-1b IL-6, MCP-1, TNF-α, FKN, IL-12P70, IL-2, IL-5 and IP-10 showed significant differences. However, expression levels of most of the 19 cytokines and chemokines decreased after therapy, especially IFN-γ, IL-10, IL-1b, IL-6, IL-8, MCP-1, TNF-α, VEGF, IL-17A, IL-2, IL-5 and MIP-1b, have a dramatic decline. Taking together, plasma levels of IFN-γ, IL-1b, IL-6, MCP-1, TNF-α, IL-2 and IL-5 are significantly increased in NPC patients and dramatically decreased after treatment, suggesting these cytokines and chemokines might play important roles in the progress of NPC. More interestingly, the expression level of MPC-1 is significantly associated with clinical stage. MCP-1 might involve in the genesis and development process of NPC, which might serve as a noninvasive biomarker for early diagnosis.

  16. Comparison of Rapid Arc and Intensity-modulated Radiotherapy Plans Using Unified Dosimetry Index and the Impact of Conformity Index on Unified Dosimetry Index Evaluation.

    Science.gov (United States)

    Krishnan, Jayapalan; Shetty, Jayarama; Rao, Suresh; Hegde, Sanath; Shambhavi, C

    2017-01-01

    The aim of this study was to evaluate the impact of conformity index in the unified dosimetry index (UDI) score for two different planning techniques namely intensity-modulated radiotherapy (IMRT) and Rapid Arc. Rapid Arc and IMRT plans of 57 patients were evaluated and compared using UDI score which incorporates four indices. To determine the impact of conformity index on the IMRT and Rapid Arc plans, UDI at conformity index one of all plan (UDIunit_CI) score was calculated by assuming conformity index is equal to one. Mean and standard deviations of all indices were calculated. Rapid Arc technique plans of different treatment sites of all patients scored lesser UDI than IMRT plans, and the conformity index of Rapid Arc plan was significantly better than IMRT plan. The average dose gradient, homogeneity, coverage, and conformity index of all sites with Rapid Arc plans were 0.212 ± 0.05, 1.123 ± 0.03, 0.959 ± 0.03, and 1.056 ± 0.09; with IMRT plans were 0.190 ± 0.05, 1.113 ± 0.04, 0.950 ± 0.04, and 1.172 ± 0.16, respectively. UDI score value with actual conformity index of Rapid Arc and IMRT plans differed significantly (P conformity index equal to one did not differ significantly (P = 0.528). In the comparison of IMRT and Rapid Arc plans using the UDI score, the impact of conformity index was significant.

  17. Improving Target Coverage and Organ-at-Risk Sparing in Intensity-Modulated Radiotherapy for Cervical Oesophageal Cancer Using a Simple Optimisation Method

    Science.gov (United States)

    Huang, Bao-Tian; Wu, Li-Li; Xie, Wen-Jia; Chen, Zhi-Jian; Li, De-Rui; Xie, Liang-Xi

    2015-01-01

    Purpose To assess the performance of a simple optimisation method for improving target coverage and organ-at-risk (OAR) sparing in intensity-modulated radiotherapy (IMRT) for cervical oesophageal cancer. Methods For 20 selected patients, clinically acceptable original IMRT plans (Original plans) were created, and two optimisation methods were adopted to improve the plans: 1) a base dose function (BDF)-based method, in which the treatment plans were re-optimised based on the original plans, and 2) a dose-controlling structure (DCS)-based method, in which the original plans were re-optimised by assigning additional constraints for hot and cold spots. The Original, BDF-based and DCS-based plans were compared with regard to target dose homogeneity, conformity, OAR sparing, planning time and monitor units (MUs). Dosimetric verifications were performed and delivery times were recorded for the BDF-based and DCS-based plans. Results The BDF-based plans provided significantly superior dose homogeneity and conformity compared with both the DCS-based and Original plans. The BDF-based method further reduced the doses delivered to the OARs by approximately 1–3%. The re-optimisation time was reduced by approximately 28%, but the MUs and delivery time were slightly increased. All verification tests were passed and no significant differences were found. Conclusion The BDF-based method for the optimisation of IMRT for cervical oesophageal cancer can achieve significantly better dose distributions with better planning efficiency at the expense of slightly more MUs. PMID:25768733

  18. Intensity-Modulated Radiotherapy in the Treatment of Oropharyngeal Cancer: An Update of the Memorial Sloan-Kettering Cancer Center Experience

    Energy Technology Data Exchange (ETDEWEB)

    Setton, Jeremy; Caria, Nicola; Romanyshyn, Jonathan; Koutcher, Lawrence; Wolden, Suzanne L.; Zelefsky, Michael J.; Rowan, Nicholas [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Sherman, Eric J.; Fury, Matthew G.; Pfister, David G. [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Wong, Richard J.; Shah, Jatin P.; Kraus, Dennis H. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Shi Weiji; Zhang Zhigang [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Schupak, Karen D.; Gelblum, Daphna Y.; Rao, Shyam D. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Lee, Nancy Y., E-mail: Leen2@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2012-01-01

    Purpose: To update the Memorial Sloan-Kettering Cancer Center's experience with intensity-modulated radiotherapy (IMRT) in the treatment of oropharyngeal cancer (OPC). Methods and Materials: Between September 1998 and April 2009, 442 patients with histologically confirmed OPC underwent IMRT at our center. There were 379 men and 63 women with a median age of 57 years (range, 27-91). The disease was Stage I in 2%, Stage II in 4%, Stage III in 21%, and Stage IV in 73% of patients. The primary tumor subsite was tonsil in 50%, base of tongue in 46%, pharyngeal wall in 3%, and soft palate in 2%. The median prescription dose to the planning target volume of the gross tumor was 70 Gy for definitive (n = 412) cases and 66 Gy for postoperative cases (n = 30). A total 404 patients (91%) received chemotherapy, including 389 (88%) who received concurrent chemotherapy, the majority of which was platinum-based. Results: Median follow-up among surviving patients was 36.8 months (range, 3-135). The 3-year cumulative incidence of local failure, regional failure, and distant metastasis was 5.4%, 5.6%, and 12.5%, respectively. The 3-year OS rate was 84.9%. The incidence of late dysphagia and late xerostomia {>=}Grade 2 was 11% and 29%, respectively. Conclusions: Our results confirm the feasibility of IMRT in achieving excellent locoregional control and low rates of xerostomia. According to our knowledge, this study is the largest report of patients treated with IMRT for OPC.

  19. Development and verification of a time delivery model for prostate intensity modulated radiotherapy using a Siemens(®) Artiste™ 160 Multi-leaf Collimator Linac.

    Science.gov (United States)

    Fourie, Nicola; Ali, Omer A; Rae, William I D

    2017-03-01

    Time delivery models thus far proposed for prediction of radiotherapy delivery times are not applicable to all makes of Linac. Our purpose was to develop a time delivery model, which would also be applicable for a Siemens(®) ARTISTE™ 160 Multi-leaf Collimator (MLC) linear accelerator (Linac) and validate the model using prostate Intensity Modulated Radiation Therapy (IMRT) treatment plans. To our knowledge, a time delivery model has not yet been proposed for a Siemens(®) ARTISTE™ 160 MLC Linac. We used the principles of the time delivery model created for a Varian(®) Linac and added the radio frequency (RF) wave component, and the MLC delay time to the MLC travel time component. Machine input parameters were confirmed using a WIN(®) stopwatch. We tested our derived model by selecting ten random 15 MV prostate IMRT treatment plans from our clinic. The delivery time was measured three times, once per day on three different days. The calculated and measured times were compared by means of correlation. The time delivery ranged between 314 and 480 s. The largest percentage difference was 3.3% (16 s) and the smallest 0.2% (1 s); the mean percentage difference was 1.9%. MLC delay and MLC speed, representing segment delivery, had the greatest uncertainties. From the successfully verified time delivery model created, it is concluded that the inter-segmental component of the process is most time-consuming. In order to decrease delivery time it is proposed that the total segments of a treatment plan be decreased.

  20. Long-Term Clinical Outcome of Intensity-Modulated Radiotherapy for Inoperable Non-Small Cell Lung Cancer: The MD Anderson Experience

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Zhiqin [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai (China); Yang Kunyu [Cancer Centre, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Komaki, Ritsuko; Wei Xiong [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Tucker, Susan L. [Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Zhuang Yan; Martel, Mary K.; Vedam, Sastray; Balter, Peter [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Zhu Guangying [Department of Radiation Oncology, Peking University School of Oncology, Beiijng Cancer Hospital and Institute, Beijing (China); Gomez, Daniel [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Lu, Charles [Department of Thoracic Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Mohan, Radhe [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Cox, James D. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Liao Zhongxing, E-mail: zliao@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2012-05-01

    Purpose: In 2007, we published our initial experience in treating inoperable non-small-cell lung cancer (NSCLC) with intensity-modulated radiation therapy (IMRT). The current report is an update of that experience with long-term follow-up. Methods and Materials: Patients in this retrospective review were 165 patients who began definitive radiotherapy, with or without chemotherapy, for newly diagnosed, pathologically confirmed NSCLC to a dose of {>=}60 Gy from 2005 to 2006. Early and late toxicities assessed included treatment-related pneumonitis (TRP), pulmonary fibrosis, esophagitis, and esophageal stricture, scored mainly according to the Common Terminology Criteria for Adverse Events 3.0. Other variables monitored were radiation-associated dermatitis and changes in body weight and Karnofsky performance status. The Kaplan-Meier method was used to compute survival and freedom from radiation-related acute and late toxicities as a function of time. Results: Most patients (89%) had Stage III to IV disease. The median radiation dose was 66 Gy given in 33 fractions (range, 60-76 Gy, 1.8-2.3 Gy per fraction). Median overall survival time was 1.8 years; the 2-year and 3-year overall survival rates were 46% and 30%. Rates of Grade {>=}3 maximum TRP (TRP{sub max}) were 11% at 6 months and 14% at 12 months. At 18 months, 86% of patients had developed Grade {>=}1 maximum pulmonary fibrosis (pulmonary fibrosis{sub max}) and 7% Grade {>=}2 pulmonary fibrosis{sub max}. The median times to maximum esophagitis (esophagitis{sub max}) were 3 weeks (range, 1-13 weeks) for Grade 2 and 6 weeks (range, 3-13 weeks) for Grade 3. A higher percentage of patients who experienced Grade 3 esophagitis{sub max} later developed Grade 2 to 3 esophageal stricture. Conclusions: In our experience, using IMRT to treat NSCLC leads to low rates of pulmonary and esophageal toxicity, and favorable clinical outcomes in terms of survival.

  1. Influence of jaw tracking in intensity-modulated and volumetric-modulated arc radiotherapy for head and neck cancers: a dosimetric study

    Energy Technology Data Exchange (ETDEWEB)

    Mani, Karthick Raj [Research and Development Centre, Bharathiar University, Tamilnadu (India); Upadhayay, Sagar [Radiation Oncology, Kathmandu Cancer Center, Bhaktapur (Nepal); Das, K. J. Maria [Dept. of Radiotherapy, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Uttar Pradesh (India)

    2017-03-15

    To Study the dosimetric advantage of the Jaw tracking technique in intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for Head and Neck Cancers. We retrospectively selected 10 previously treated head and neck cancer patients stage (T1/T2, N1, M0) in this study. All the patients were planned for IMRT and VMAT with simultaneous integrated boost technique. IMRT and VMAT plans were performed with jaw tracking (JT) and with static jaw (SJ) technique by keeping the same constraints and priorities for a particular patient. Target conformity, dose to the critical structures and low dose volumes were recorded and analyzed for IMRT and VMAT plans with and without JT for all the patients. The conformity index average of all patients followed by standard deviation (x¯x¯ ± σx¯σx¯) of the JT-IMRT, SJ-IMRT, JT-VMAT, and SJ-VMAT were 1.72 ± 0.56, 1.67 ± 0.57, 1.83 ± 0.65, and 1.85 ± 0.64, and homogeneity index were 0.059 ± 0.05, 0.064 ± 0.05, 0.064 ± 0.04, and 0.064 ± 0.05. JT-IMRT shows significant mean reduction in right parotid and left parotid shows of 7.64% (p < 0.001) and 7.45% (p < 0.001) compare to SJ-IMRT. JT-IMRT plans also shows considerable dose reduction to thyroid, inferior constrictors, spinal cord and brainstem compared to the SJ-IMRT plans. Significant dose reductions were observed for critical structure in the JT-IMRT compared to SJ-IMRT technique. In JT-VMAT plans dose reduction to the critical structure were not significant compared to the SJ-IMRT due to relatively lesser monitor units.

  2. Simulational study of a dosimetric comparison between a Gamma Knife treatment plan and an intensity-modulated radiotherapy plan for skull base tumors.

    Science.gov (United States)

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

    2014-05-01

    Fractionated stereotactic radiotherapy (SRT) is performed with a linear accelerator-based system such as Novalis. Recently, Gamma Knife Perfexion (PFX) featured the Extend system with relocatable fixation devices available for SRT. In this study, the dosimetric results of these two modalities were compared from the viewpoint of conformity, heterogeneity and gradient in target covering. A total of 14 patients with skull base tumors were treated with Novalis intensity-modulated (IM)-SRT. Treatment was planned on an iPlan workstation. Five- to seven-beam IM-SRT was performed in 14-18 fractions with a fraction dose of 2.5 or 3 Gy. With these patients' data, additional treatment planning was simulated using a GammaPlan workstation for PFX-SRT. Reference CT images with planning structure contour sets on iPlan, including the planning target volume (PTV, 1.1-102.2 ml) and organs at risk, were exported to GammaPlan in DICOM-RT format. Dosimetric results for Novalis IM-SRT and PFX-SRT were evaluated in the same prescription doses. The isocenter number of PFX was between 12 and 50 at the isodose contour of 50-60%. The PTV coverage was 95-99% for Novalis and 94-98% for PFX. The conformity index (CI) was 1.11-1.61 and 1.04-1.15, the homogeneity index (HI) was 1.1-3.62 and 2.3-3.25, and the gradient index (GI) was 3.72-7.97 and 2.54-3.39 for Novalis and PFX, respectively. PTV coverage by Novalis and PFX was almost equivalent. PFX was superior in CI and GI, and Novalis was better in HI. Better conformality would be achieved by PFX, when the homogeneity inside tumors is less important.

  3. Prognostic Correlations between ABO Blood Group and Pre-Treatment Plasma Epstein-Barr Virus DNA in Patients with Nasopharyngeal Carcinoma Receiving Intensity-Modulated Radiotherapy.

    Science.gov (United States)

    Peng, Hao; Chen, Lei; Li, Wen-Fei; Zhang, Yuan; Liu, Li-Zhi; Tian, Li; Lin, Ai-Hua; Sun, Ying; Ma, Jun

    2016-01-01

    The objective of this study is to assess the prognostic value of ABO blood group in nasopharyngeal carcinoma (NPC) treated by intensity-modulated radiotherapy (IMRT). We retrospectively reviewed the data on 1397 patients with non-metastatic, newly diagnosed NPC treated using IMRT. Patient survival between different ABO blood groups were compared using log-rank test. Cox hazards model was adopted to establish independent prognostic factors. In our study, the distribution of the A, B, AB and O blood groups was 26.6% (372/1397), 26.2% (366/1397), 5.2% (73/1397) and 42.0% (586/1397), respectively. The cut-off value of pre-treatment Epstein-Barr virus (EBV) DNA based on disease-free survival (DFS) was 1355 copies/ml (area under curve [AUC], 0.649; sensitivity, 0.76; specificity, 0.496) for the whole cohort. Estimated four-year DFS, overall survival (OS), distant metastasis-free survival (DMFS) and locoregional relapse-free survival (LRRFS) rates were 81.7%, 89.2%, 89.4% and 92.3% for blood group A; 82.1%, 89.3%, 89.0% and 92.0% for group B; 83.3%, 88.1%, 86.2% and 95.5% for group AB, 80.9%, 90.7%, 88.4% and 90.2% for group O (P > 0.05 for all rates). Multivariate analysis revealed ABO blood group was not an independent prognostic factor for DFS, OS, DMFS or LRRFS (P > 0.05 for all rates) after adjusting for plasma EBV DNA in either the whole cohort or subgroup analysis by gender. The prognostic value of ABO blood group may be limited for patients with NPC in the era of IMRT, and no substantial correlation between ABO blood group and plasma EBV DNA was observed.

  4. Outcome and patterns of failure after postoperative intensity modulated radiotherapy for locally advanced or high-risk oral cavity squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Geretschläger Andreas

    2012-10-01

    Full Text Available Abstract Background To determine the outcome and patterns of failure in oral cavity cancer (OCC patients after postoperative intensity modulated radiotherapy (IMRT with concomitant systemic therapy. Methods All patients with locally advanced (AJCC stage III/IV or high-risk OCC (AJCC stage II who underwent postoperative IMRT at our institution between December 2006 and July 2010 were retrospectively analyzed. The primary endpoint was locoregional recurrence-free survival (LRRFS. Secondary endpoints included distant metastasis-free survival (DMFS, overall survival (OS, acute and late toxicities. Results Overall 53 patients were analyzed. Twenty-three patients (43% underwent concomitant chemotherapy with cisplatin, two patients with carboplatin (4% and four patients were treated with the monoclonal antibody cetuximab (8%. At a median follow-up of 2.3 (range, 1.1–4.6 years the 3-year LRRFS, DMFS and OS estimates were 79%, 90%, and 73% respectively. Twelve patients experienced a locoregional recurrence. Eight patients, 5 of which had both a flap reconstruction and extracapsular extension (ECE, showed an unusual multifocal pattern of recurrence. Ten locoregional recurrences occurred marginally or outside of the high-risk target volumes. Acute toxicity grades of 2 (27% and 3 (66% and late toxicity grades of 2 (34% and 3 (11% were observed. Conclusion LRRFS after postoperative IMRT is satisfying and toxicity is acceptable. The majority of locoregional recurrences occurred marginally or outside of the high-risk target volumes. Improvement of high-risk target volume definition especially in patients with flap reconstruction and ECE might transfer into better locoregional control.

  5. Intensity-Modulated Radiotherapy with a Simultaneous Integrated Boost Combined with Chemotherapy in Stages III-IV Hypopharynx-Larynx Cancer: Treatment Compliance and Clinical Outcomes

    Directory of Open Access Journals (Sweden)

    Giovanni Franchin

    2014-01-01

    Full Text Available Objectives. Retrospective review of our experience using intensity-modulated radiotherapy with simultaneous integrated boost (SIB-IMRT combined with chemotherapy as the primary treatment of locoregionally advanced larynx and hypopharynx cancers. Materials and Methods. Between September 2008 and June 2012, 60 patients (26 with larynx and 34 hypopharynx cancers were treated. Our policy was to offer SIB-IMRT plus concurrent cisplatin to patients affected by larynx cancer stage T3N0-N1 and NCT with TPF (docetaxel/cisplatin/fluorouracil followed by SIB-IMRT to patients with larynx cancer stage T2-4N2-3 or hypopharynx cancer T2-4N0-3. SIB-IMRT consisted in a total dose of 70.95 Gy (2.15 Gy/fraction, 5 fractions/week to the gross primary and nodal disease and differentiated dosages for high risk and low risk nodal regions. Results. Complete remission was achieved in 53/60 (88% of patients. At a median follow up of 31 months (range 9–67, the rate of overall survival and locoregional control with functional larynx at 3 years were 68% and 60%, respectively. T stage (T1–3 versus T4 resulted in being significant for predicting 3-year freedom from relapse (it was 69% and 35%, resp., for T1–T3 and T4 tumors; P=0.04, while site of primary disease (larynx versus hypopharynx was not significant (P=0.35. Conclusion. Our results indicated that combining SIB-IMRT with induction chemotherapy or concurrent chemotherapy is an effective treatment strategy for organ preservation in advanced larynx/hypopharynx cancer.

  6. The Impact of Clinical Stage on Radiation Doses to Organs at Risk Following Intensity-modulated Radiotherapy in Nasopharyngeal Carcinoma: A Prospective Analysis.

    Science.gov (United States)

    Xu, Lin; Yao, Ji-Jin; Zhou, Guan-Qun; Zhang, Wang-Jian; Liu, Guo-Long; Liu, Li-Zhi; Ma, Jun; Sun, Ying

    2016-01-01

    Background: The development of intensity-modulated radiotherapy (IMRT) has revolutionized the management of nasopharyngeal carcinoma (NPC). The purpose of this study was to investigate the impact of clinical stage on radiation doses to organs at risk (OARs) in NPC. Material and Methods: One hundred and forty-eight patients with newly diagnosed and untreated NPC were prospectively enrolled. Based on the anatomic definition and pathogenesis of radiation induced injury, a total of 28 OARs surrounding the nasopharynx were contoured on axial computed tomography (CT) planning images in each patient. Dose-volume histograms, as well as the mean and maximal doses for each structure, were calculated. Results: Radiation doses to 15 OARs (including the brain stem, temporal lobe and eye) were positively correlated with T stage, the radiation doses to 13 OARs (including the brachial plexus, parotid and thyroid) increased significantly with N stage, and the radiation doses to the spinal cord and mandible had no association with T or N stage. Based on the characteristic of excess rates, 9 OARs (e.g. spinal cord, eye, trachea, and et al.) met tolerance doses easily in all stages, 9 OARs (e.g. brain stem, temporal lobe, brachial plexus, and et al.) easily in early stages but with difficulty in advanced stages, and 10 OARs (e.g. cochlea, parotid, thyroid, and et al.) with difficulty in all stages. Conclusions: The radiation doses to most of OARs are associated with T or N stage, and there are three kinds of patterns for them: 1) meet tolerance doses easily in all stages; 2) meet tolerance doses easily in early stages but with difficulty in advanced stages; and 3) meet tolerance doses with difficulty in all stages.

  7. Intensity-modulated radiotherapy for stage IVA/IVB nasopharyngeal carcinoma: clinical outcomes and patterns of failure in an endemic area in China.

    Science.gov (United States)

    Zeng, Lei; Tian, Yun-Ming; Sun, Xue-Ming; Huang, Ying; Chen, Chun-Yan; Han, Fei; Liu, Shuai; Lan, Mei; Guan, Ying; Deng, Xiao-Wu; Lu, Tai-Xiang

    2014-10-01

    The purpose of this study was to analyze the mode of relapse patterns and survival of 209 patients with stage IVA and IVB nasopharyngeal carcinoma (NPC). A total of 209 patients who underwent magnetic resonance imaging (MRI) and were subsequently histologically diagnosed with nondisseminated stage IV NPC received intensity-modulated radiotherapy (IMRT) as their primary treatment and were included in this retrospective study. Median follow-up time was 65 months (range, 3-108 months). The 5-year overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) rates for patients with stage IVA and stage IVB NPC were 72.7 vs. 60.0 % (p = 0.319), 62.9 vs. 51.3 % (p = 0.070), 82.9 vs. 93.1 % (p = 0.070), 82.9 vs. 82.9 % (p = 0.897), 76.4 vs. 58.5 % (p = 0.003), respectively. Age older than 44 years was found to be a statistically significant adverse independent prognostic factor for OS. Patients with advanced N status had worse OS, DFS, and DMFS rates. Patients with a primary gross tumor volume (GTV-P) ≥ 55.11 ml had worse OS, DFS, and LRRFS rates. The results of treating stage IVA NPC with IMRT were excellent. Distant metastasis remains the most difficult treatment challenge for patients with stage IVA and IVB NPC, and more effective systemic chemotherapy should be explored.

  8. Ballistic optimisation with intensity modulation with integration of a concomitant boost for the radiotherapy of glioblastomas; Optimisation de la balistique en modulation d'intensite avec integration d'un boost concomitant pour la radiotherapie des glioblastomes

    Energy Technology Data Exchange (ETDEWEB)

    Supper, C.; Franceries, X. [Universite Paul-Sabatier, 31 - Toulouse (France); Supper, C.; Vieillevigne, L.; Ken, S.; Simon, L.; Rives, M.; Moyal, E.; Delannes, M.; Noel, A.; Laprie, A. [Deparement de radiotherapie, Institut Claudius-Regaud, 31 - Toulouse (France); Franceries, X.; Ken, S.; Laprie, A. [Inserm UMR 825 Imagerie cerebrale et handicapes neurologiques, 31 - Toulouse (France); Noel, A. [Departement de radiotherapie, Centre Alexis-Vautrin, 54 - Nancy (France)

    2010-10-15

    The authors report a study aimed at the optimisation of the ballistics of intensity-modulated conformation radiotherapy (IMRT) treatment with a boost for the preparation of a multi-centric prospective trial financed by a program on glioblastoma treatment. This treatment consists in using the boost technique to obtain an increase of the dose delivered by the IMRT in sites presenting a strong predictive value for relapse. These sites are defined by means of magnetic resonance spectrometric imagery. Conformation indexes, planning target volumes, doses delivered to organs at risk are analysed. The proximity of organs at risk was the main difficulty, but a good dosimetry has been obtained with the use of five coplanar beams. Short communication

  9. Treatment of left sided breast cancer for a patient with funnel chest: Volumetric-modulated arc therapy vs. 3D-CRT and intensity-modulated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Haertl, Petra M., E-mail: petra.haertl@klinik.uni-regensburg.de [Department of Radiotherapy, Regensburg University Medical Center, Regensburg (Germany); Pohl, Fabian; Weidner, Karin; Groeger, Christian; Koelbl, Oliver; Dobler, Barbara [Department of Radiotherapy, Regensburg University Medical Center, Regensburg (Germany)

    2013-04-01

    This case study presents a rare case of left-sided breast cancer in a patient with funnel chest, which is a technical challenge for radiation therapy planning. To identify the best treatment technique for this case, 3 techniques were compared: conventional tangential fields (3D conformal radiotherapy [3D-CRT]), intensity-modulated radiotherapy (IMRT), and volumetric-modulated arc therapy (VMAT). The plans were created for a SynergyS® (Elekta, Ltd, Crawley, UK) linear accelerator with a BeamModulator™ head and 6-MV photons. The planning system was Oncentra Masterplan® v3.3 SP1 (Nucletron BV, Veenendal, Netherlands). Calculations were performed with collapsed cone algorithm. Dose prescription was 50.4 Gy to the average of the planning target volume (PTV). PTV coverage and homogeneity was comparable for all techniques. VMAT allowed reducing dose to the ipsilateral organs at risk (OAR) and the contralateral breast compared with IMRT and 3D-CRT: The volume of the left lung receiving 20 Gy was 19.3% for VMAT, 26.1% for IMRT, and 32.4% for 3D-CRT. In the heart, a D{sub 15%} of 9.7 Gy could be achieved with VMAT compared with 14 Gy for IMRT and 46 Gy for 3D-CRT. In the contralateral breast, D{sub 15%} was 6.4 Gy for VMAT, 8.8 Gy for IMRT, and 10.2 Gy for 3D-CRT. In the contralateral lung, however, the lowest dose was achieved with 3D-CRT with D{sub 10%} of 1.7 Gy for 3D-CRT, and 6.7 Gy for both IMRT and VMAT. The lowest number of monitor units (MU) per 1.8-Gy fraction was required by 3D-CRT (192 MU) followed by VMAT (518 MU) and IMRT (727 MU). Treatment time was similar for 3D-CRT (3 min) and VMAT (4 min) but substantially increased for IMRT (13 min). VMAT is considered the best treatment option for the presented case of a patient with funnel chest. It allows reducing dose in most OAR without compromising target coverage, keeping delivery time well below 5 minutes.

  10. Treatment of left sided breast cancer for a patient with funnel chest: volumetric-modulated arc therapy vs. 3D-CRT and intensity-modulated radiotherapy.

    Science.gov (United States)

    Haertl, Petra M; Pohl, Fabian; Weidner, Karin; Groeger, Christian; Koelbl, Oliver; Dobler, Barbara

    2013-01-01

    This case study presents a rare case of left-sided breast cancer in a patient with funnel chest, which is a technical challenge for radiation therapy planning. To identify the best treatment technique for this case, 3 techniques were compared: conventional tangential fields (3D conformal radiotherapy [3D-CRT]), intensity-modulated radiotherapy (IMRT), and volumetric-modulated arc therapy (VMAT). The plans were created for a SynergyS® (Elekta, Ltd, Crawley, UK) linear accelerator with a BeamModulator™ head and 6-MV photons. The planning system was Oncentra Masterplan® v3.3 SP1 (Nucletron BV, Veenendal, Netherlands). Calculations were performed with collapsed cone algorithm. Dose prescription was 50.4 Gy to the average of the planning target volume (PTV). PTV coverage and homogeneity was comparable for all techniques. VMAT allowed reducing dose to the ipsilateral organs at risk (OAR) and the contralateral breast compared with IMRT and 3D-CRT: The volume of the left lung receiving 20 Gy was 19.3% for VMAT, 26.1% for IMRT, and 32.4% for 3D-CRT. In the heart, a D(15%) of 9.7 Gy could be achieved with VMAT compared with 14 Gy for IMRT and 46 Gy for 3D-CRT. In the contralateral breast, D(15%) was 6.4 Gy for VMAT, 8.8 Gy for IMRT, and 10.2 Gy for 3D-CRT. In the contralateral lung, however, the lowest dose was achieved with 3D-CRT with D(10%) of 1.7 Gy for 3D-CRT, and 6.7 Gy for both IMRT and VMAT. The lowest number of monitor units (MU) per 1.8-Gy fraction was required by 3D-CRT (192 MU) followed by VMAT (518 MU) and IMRT (727 MU). Treatment time was similar for 3D-CRT (3 min) and VMAT (4 min) but substantially increased for IMRT (13 min). VMAT is considered the best treatment option for the presented case of a patient with funnel chest. It allows reducing dose in most OAR without compromising target coverage, keeping delivery time well below 5 minutes.

  11. Cervix carcinomas: place of intensity-modulated radiotherapy; Les cancers du col uterin: place de la radiotherapie avec modulation d'intensite

    Energy Technology Data Exchange (ETDEWEB)

    Barillot, I. [Centre Regional Universitaire de Cancerologie H.S.-Kaplan, Hopital Bretonneau, CHU de Tours, 37 - Tours (France); Universite Francois-Rabelais, 37 - Tours (France)

    2009-10-15

    While indications of modulated intensity radiation therapy (I.M.R.T.) are perfectly defined in head and neck and prostate cancer patients, this technique remains under evaluation for gynecologic tumours. The implementation of conformal three dimensional radiotherapy in the late 1990 has been the first important step for optimisation of treatment of cervix carcinomas, as it permitted a better target coverage with a significant reduction of the bladder dose. However, this technique often leads to an irradiation of a larger volume of rectum in locally advanced stages and could only spare a limited amount of intestine. I.R.M.T. is one of the optimisation methods potentially efficient for a better sparing of digestive tract during irradiation of cervix carcinomas. The aim of this literature review is to provide the arguments supporting this hypothesis, and to define the place of this technique for dose escalation. (authors)

  12. The reoxygenation of hypoxia and the reduction of glucose metabolism in head and neck cancer by fractionated radiotherapy with intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Shozo; Shiga, Tohru; Watanabe, Shiro; Hirata, Kenji; Magota, Keiichi; Kasai, Katsuhiko; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Hokkaido (Japan); Yasuda, Koichi; Onimaru, Rikiya; Tuchiya, Kazuhiko; Shirato, Hiroki [Hokkaido University Graduate School of Medicine, Department of Radiology, Hokkaido (Japan); Nishijima, Ken-ichi; Kuge, Yuji [Hokkaido University, Central Institute of Isotope Science, Hokkaido (Japan)

    2016-11-15

    The purpose of this study was to prospectively investigate reoxygenation in the early phase of fractionated radiotherapy and serial changes of tumoricidal effects associated with intensity-modulated radiation therapy (IMRT) in patients with head and neck cancer (HNC) using F-18 fluoromisonidazole (FMISO) PET and F-18 fluorodeoxyglucose (FDG) PET. Patients with untreated HNC underwent FMISO-PET and FDG-PET studies prospectively. A PET evaluation was conducted before each IMRT (Pre-IMRT), during IMRT (at 30 Gy/15 fr) (Inter-IMRT), and after completion of IMRT (70 Gy/35 fr) (Post-IMRT). FMISO-PET images were scanned by a PET/CT scanner at 4 h after the FMISO injection. We quantitatively analyzed the FMISO-PET images of the primary lesion using the maximum standardized uptake (SUVmax) and tumor-to-muscle ratio (TMR). The hypoxic volume (HV) was calculated as an index of tumor hypoxia, and was defined as the volume when the TMR was ≥ 1.25. Each FDG-PET scan was started 1 h after injection. The SUVmax and metabolic tumor volume (MTV) values obtained by FDG-PET were analyzed. Twenty patients finished the complete PET study protocol. At Pre-IMRT, 19 patients had tumor hypoxia in the primary tumor. In ten patients, the tumor hypoxia disappeared at Inter-IMRT. Another seven patients showed the disappearance of tumor hypoxia at Post-IMRT. Two patients showed tumor hypoxia at Post-IMRT. The FMISO-PET results showed that the reduction rates of both SUVmax and TMR from Pre-IMRT to Inter-IMRT were significantly higher than the corresponding reductions from Inter-IMRT to Post-IMRT (SUVmax: 27 % vs. 10 %, p = 0.025; TMR: 26 % vs. 12 %, p = 0.048). The reduction rate of SUVmax in FDG-PET from Pre-IMRT to Inter-IMRT was similar to that from Inter-IMRT to Post-IMRT (47 % vs. 48 %, p = 0.778). The reduction rate of the HV in FMISO-PET from Pre-IMRT to Inter-IMRT tended to be larger than that from Inter-IMRT to Post-IMRT (63 % vs. 40 %, p = 0.490). Conversely, the reduction rate of

  13. Benefit of intensity modulated and image-guided radiotherapy in prostate cancer; Apports de la radiotherapie avec modulation d'intensite guidee par l'image dans les cancers prostatiques

    Energy Technology Data Exchange (ETDEWEB)

    Latorzeff, I.; Mazurier, J. [Service de radiotherapie, groupe Oncorad-Garonne, clinique Pasteur, -L' Atrium-, 31 - Toulouse (France); Boutry, C.; Dudouet, P. [Service d' oncologie, groupe Oncorad-Garonne, clinique du Pont-de-Chaume, 82 - Montauban (France); Richaud, P. [Departement de radiotherapie, institut Bergonie, 33 - Bordeaux (France); Crevoisier, R. de [Departement de radiotherapie, centre Eugene-Marquis, 35 - Rennes (France)

    2010-10-15

    External beam radiotherapy (RT) is used to treat all stages of localized prostate cancer. Using a 3D conformal RT (3DCRT) without any androgen deprivation, a clear dose-effect relationship has been shown in terms of both biochemical control and also unfortunately of rectal and urinary toxicity. Compared to a 'standard' 3DCRT, intensity modulated RT (IMRT) improves the dose distribution by mainly providing concave dose distribution and tight dose gradients. Based on large clinical experiences for at least one decade, IMRT is widely used to increase the dose in the prostate and therefore local control, without increasing toxicity. Indeed, toxicity rates observed after high dose delivered in the prostate (80 Gy) with IMRT appear no different than those observed after a standard dose (70 Gy) delivered by a standard 3DCRT. Arc IMRT appears a new promising IMRT modality, decreasing dramatically treatment duration. However, this IMRT-based dosimetric benefit may not be translated into a full clinical benefit, if intra-pelvic prostate motion is not taken in account. Image-guided radiotherapy (IGRT) should be therefore associated with IMRT for a maximal clinical benefit. This article is a literature review showing the interest of both combined approaches. (authors)

  14. Dosimetric difference amongst 3 techniques: TomoTherapy, sliding-window intensity-modulated radiotherapy (IMRT), and RapidArc radiotherapy in the treatment of late-stage nasopharyngeal carcinoma (NPC).

    Science.gov (United States)

    Lee, Francis Kar-ho; Yip, Celia Wai-yi; Cheung, Frankie Chun-hung; Leung, Alex Kwok-cheung; Chau, Ricky Ming-chun; Ngan, Roger Kai-cheong

    2014-01-01

    To investigate the dosimetric difference amongst TomoTherapy, sliding-window intensity-modulated radiotherapy (IMRT), and RapidArc radiotherapy in the treatment of late-stage nasopharyngeal carcinoma (NPC). Ten patients with late-stage (Stage III or IV) NPC treated with TomoTherapy or IMRT were selected for the study. Treatment plans with these 3 techniques were devised according to departmental protocol. Dosimetric parameters for organ at risk and treatment targets were compared between TomoTherapy and IMRT, TomoTherapy and RapidArc, and IMRT and RapidArc. Comparison amongst the techniques was done by statistical tests on the dosimetric parameters, total monitor unit (MU), and expected delivery time. All 3 techniques achieved similar target dose coverage. TomoTherapy achieved significantly lower doses in lens and mandible amongst the techniques. It also achieved significantly better dose conformity to the treatment targets. RapidArc achieved significantly lower dose to the eye and normal tissue, lower total MU, and less delivery time. The dosimetric advantages of the 3 techniques were identified in the treatment of late-stage NPC. This may serve as a guideline for selection of the proper technique for different clinical cases. © 2013 American Association of Medical Dosimetrists Published by American Association of Medical Dosimetrists All rights reserved.

  15. Comparison of 3D conformal radiotherapy vs. intensity modulated radiation therapy (IMRT) of a stomach cancer treatment;Comparacion dosimetrica de radioterapia conformal 3D versus radioterapia de intensidad modulada (IMRT) de un tratamiento de cancer de estomago

    Energy Technology Data Exchange (ETDEWEB)

    Bernui de V, Maria Giselle; Cardenas, Augusto; Vargas, Carlos [Hospital Nacional Carlos Alberto Seguin Escobedo (ESSALUD), Arequipa (Peru). Servicio de Radioterapia

    2009-07-01

    The purpose of this work was to compare the dosimetry in 3D Conformal Radiotherapy with Intensity Modulated Radiation Therapy (IMRT) in a treatment of stomach cancer. For this comparison we selected a patient who underwent subtotal gastrectomy and D2 dissection for a T3N3 adenocarcinoma Mx ECIIIB receiving treatment under the scheme Quimio INT 0116 - in adjuvant radiotherapy. In the treatment plan was contouring the Clinical Target Volume (CTV) and the Planning Target Volume (PTV) was generated from the expansion of 1cm of the CTV, the risky organs contouring were: the liver, kidneys and spinal cord, according to the consensus definition of volumes in gastric cancer. The 3D Conformal Radiotherapy planning is carried out using 6 half beams following the Leong Trevol technique; for the IMRT plan was used 8 fields, the delivery technique is step-and-shoot. In both cases the fields were coplanar, isocentric and the energy used was 18 MV. Intensity Modulated Radiation Therapy (IMRT), in this case has proved to be a good treatment alternative to the technique of 3D Conformal Radiotherapy; the dose distributions with IMRT have better coverage of PTV and positions of the hot spots, as well as the kidneys volume that received higher doses to 2000 cGy is lower, but the decrease in dose to the kidneys is at the expense of increased dose in other organs like the liver. (author)

  16. Prognoses and long-term outcomes of nasopharyngeal carcinoma in Han and Uyghur patients treated with intensity-modulated radiotherapy in the Xinjiang Autonomous Region of China.

    Directory of Open Access Journals (Sweden)

    Ruozheng Wang

    Full Text Available OBJECTIVES: The objective of this study was to investigate the long-term outcomes and prognostic factors for nasopharyngeal carcinoma (NPC in Han and Uyghur patients treated with intensity-modulated radiotherapy (IMRT in the Xinjiang region of China. MATERIALS AND METHODS: One hundred twenty-one Han and 60 Uyghur patients with newly diagnosed NPC without distant metastasis received IMRT at the Affiliated Tumor Hospital of Xinjiang Medical University between 2005 and 2008. The Kaplan-Meier method was used to estimate survival rates, and the log-rank test was used to evaluate differences in survival. RESULTS: Comparing Han and Uyghur patients, the 5-year overall survival (OS, disease-free survival (DFS, local control (LC, regional control (RC, and distant metastasis-free survival (DMFS rates were 81.9% vs 77.6% (P = 0.297, 72.1% vs 65.6% (P = 0.493, 88.3% vs 86.5% (P = 0.759, 95.0% vs 94.6% (P = 0.929, and 79.1% vs 75.2% (P = 0.613, respectively. Multivariate Cox proportional hazards regression identified the following independent prognostic factors in Han patients: N stage (P = 0.007 and age (P = 0.028 for OS, and age (P = 0.028 for DFS. OS differed significantly between Han and Uyghur patients >60 years old group (P = 0.036. Among Uyghur patients, the independent prognostic factors were age for OS (P = 0.033, as well as N stage (P = 0.037 and age (P = 0.021 for DFS. Additionally, Uyghur patients were less likely to experience mucositis and dermatitis than Han patients. CONCLUSION: Han and Uyghur patients with NPC had statistically significant differences in age, smoking history, and N staging. There was no significant difference in overall treatment outcomes with IMRT between these 2 ethnic populations in Xinjiang, China.

  17. Dose-Escalated Intensity-Modulated Radiotherapy Is Feasible and May Improve Locoregional Control and Laryngeal Preservation in Laryngo-Hypopharyngeal Cancers

    Energy Technology Data Exchange (ETDEWEB)

    Miah, Aisha B.; Bhide, Shreerang A.; Guerrero-Urbano, M. Teresa [Head and Neck Unit, The Royal Marsden National Health Service (NHS) Foundation Trust, London (United Kingdom); Institute of Cancer Research, London (United Kingdom); Clark, Catharine; Bidmead, A. Margaret [Institute of Cancer Research, London (United Kingdom); Department of Physics, The Royal Marsden NHS Foundation Trust, London (United Kingdom); St Rose, Suzanne; Barbachano, Yolanda; A' Hern, Roger [Department of Statistics, The Royal Marsden NHS Foundation Trust, London (United Kingdom); Tanay, Mary; Hickey, Jennifer; Nicol, Robyn; Newbold, Kate L. [Head and Neck Unit, The Royal Marsden National Health Service (NHS) Foundation Trust, London (United Kingdom); Harrington, Kevin J. [Head and Neck Unit, The Royal Marsden National Health Service (NHS) Foundation Trust, London (United Kingdom); Institute of Cancer Research, London (United Kingdom); Nutting, Christopher M., E-mail: chris.nutting@rmh.nhs.uk [Head and Neck Unit, The Royal Marsden National Health Service (NHS) Foundation Trust, London (United Kingdom); Institute of Cancer Research, London (United Kingdom)

    2012-02-01

    Purpose: To determine the safety and outcomes of induction chemotherapy followed by dose-escalated intensity-modulated radiotherapy (IMRT) with concomitant chemotherapy in locally advanced squamous cell cancer of the larynx and hypopharynx (LA-SCCL/H). Methods and Materials: A sequential cohort Phase I/II trial design was used to evaluate moderate acceleration and dose escalation. Patients with LA-SCCL/H received IMRT at two dose levels (DL): DL1, 63 Gy/28 fractions (Fx) to planning target volume 1 (PTV1) and 51.8 Gy/28 Fx to PTV2; DL2, 67.2 Gy/28 Fx and 56 Gy/28 Fx to PTV1 and PTV2, respectively. Patients received induction cisplatin/5-fluorouracil and concomitant cisplatin. Acute and late toxicities and tumor control rates were recorded. Results: Between September 2002 and January 2008, 60 patients (29 DL1, 31 DL2) with Stage III (41% DL1, 52% DL2) and Stage IV (52% DL1, 48% DL2) disease were recruited. Median (range) follow-up for DL1 was 51.2 (12.1-77.3) months and for DL2 was 36.2 (4.2-63.3) months. Acute Grade 3 (G3) dysphagia was higher in DL2 (87% DL2 vs. 59% DL1), but other toxicities were equivalent. One patient in DL1 required dilatation of a pharyngeal stricture (G3 dysphagia). In DL2, 2 patients developed benign pharyngeal strictures at 1 year. One underwent a laryngo-pharyngectomy and the other a dilatation. No other G3/G4 toxicities were reported. Overall complete response was 79% (DL1) and 84% (DL2). Two-year locoregional progression-free survival rates were 64.2% (95% confidence interval, 43.5-78.9%) in DL1 and 78.4% (58.1-89.7%) in DL2. Two-year laryngeal preservation rates were 88.7% (68.5-96.3%) in DL1 and 96.4% (77.7-99.5%) in DL2. Conclusions: At a mean follow-up of 36 months, dose-escalated chemotherapy-IMRT at DL2 has so far been safe to deliver. In this study, DL2 delivered high rates of locoregional control, progression-free survival, and organ preservation and has been selected as the experimental arm in a Cancer Research UK Phase III

  18. Dosimetric study of RapidArc plans and conventional intensity modulated radiotherapy for prostate cancer involving seminal vesicles and pelvis lymph nodes

    Directory of Open Access Journals (Sweden)

    Birendra Rout

    2016-03-01

    Full Text Available Purpose: The main purpose of this study is to (1 identify the continual diversity between conventional fixed field intensity modulation radiotherapy (IMRT and RapidArc (RA for high-risk prostate cancer; and (2 determine potential benefits and drawbacks of using for this type of treatment.Methods: A cohort of 20 prostate cases including prostate, seminal vesicles and pelvic lymph nodes was selected for this study. The primary planning target volume (PTVP and boost planning target volume (PTVB were contoured. The total prescription dose was 75.6 Gy (45 Gy to PTVP and an additional 21.6 Gy to PTVB. Two plans were generated for each PTV: multiple 7-fields for IMRT and two arcs for RA.Results: A Sigma index (IMRT: 2.75 ± 0.581; RA: 2.8 ± 0.738 for PTVP and (IMRT: 2.0 ± 0.484; RA: 2.1 ± 0.464 for PTVB indicated similar dose homogeneity inside the PTV. Conformity index (IMRT: 0.96 ± 0.047; RA: 0.95 ± 0.059 for PTVP and (IMRT: 0.97 ± 0.015; RA: 0.96 ± 0.014 for PTVB was comparable for both the techniques. IMRT offered lower mean dose to organ at risks (OARs compared to RA plans. Normal tissue integral dose in IMRT plan resulted 0.87% lower than RA plans. All the plans displayed significant increase (2.50 times for PTVP and 1.72 for PTBB in the average number of necessary monitor units (MUs with IMRT beam. Treatment delivery time of RA was 2 ‒ 6 minutes shorter than IMRT treatment.Conclusion: For PTV including pelvic lymph nodes, seminal vesicles and prostate, IMRT offered a greater degree of OARs sparing. For PTV including seminal vesicles and prostate, RA with two arcs provided comparable plan with IMRT. RA also improved the treatment efficiency due to smaller number of MUs required.

  19. Volumetric-modulated arc therapy vs conventional fixed-field intensity-modulated radiotherapy in a whole-ventricular irradiation: A planning comparison study

    Energy Technology Data Exchange (ETDEWEB)

    Sakanaka, Katsuyuki [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto (Japan); Mizowaki, Takashi, E-mail: mizo@kuhp.kyoto-u.ac.jp [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto (Japan); Sato, Sayaka; Ogura, Kengo; Hiraoka, Masahiro [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto (Japan)

    2013-07-01

    This study evaluated the dosimetric difference between volumetric-modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (cIMRT) in whole-ventricular irradiation. Computed tomography simulation data for 13 patients were acquired to create plans for VMAT and cIMRT. In both plans, the same median dose (100% = 24 Gy) was prescribed to the planning target volume (PTV), which comprised a tumor bed and whole ventricles. During optimization, doses to the normal brain and body were reduced, provided that the dose constraints of the target coverage were satisfied. The dose-volume indices of the PTV, normal brain, and body as well as monitor units were compared between the 2 techniques by using paired t-tests. The results showed no significant difference in the homogeneity index (0.064 vs 0.065; p = 0.824) of the PTV and conformation number (0.78 vs 0.77; p = 0.065) between the 2 techniques. In the normal brain and body, the dose-volume indices showed no significant difference between the 2 techniques, except for an increase in the volume receiving a low dose in VMAT; the absolute volume of the normal brain and body receiving 1 Gy of radiation significantly increased in VMAT by 1.6% and 8.3%, respectively, compared with that in cIMRT (1044 vs 1028 mL for the normal brain and 3079.2 vs 2823.3 mL for the body; p<0.001). The number of monitor units to deliver a 2.0-Gy fraction was significantly reduced in VMAT compared with that in cIMRT (354 vs 873, respectively; p<0.001). In conclusion, VMAT delivers IMRT to complex target volumes such as whole ventricles with fewer monitor units, while maintaining target coverage and conformal isodose distribution comparable to cIMRT; however, in addition to those characteristics, the fact that the volume of the normal brain and body receiving a low dose would increase in VMAT should be considered.

  20. SU-F-BRB-12: A Novel Haar Wavelet Based Approach to Deliver Non-Coplanar Intensity Modulated Radiotherapy Using Sparse Orthogonal Collimators

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, D; Ruan, D; Low, D; Sheng, K [Deparment of Radiation Oncology, University of California Los Angeles, Los Angeles, CA (United States); O’Connor, D [Deparment of Mathematics, University of California Los Angeles, Los Angeles, CA (United States); Boucher, S [RadiaBeam Technologies, Santa Monica, CA (United States)

    2015-06-15

    Purpose: Existing efforts to replace complex multileaf collimator (MLC) by simple jaws for intensity modulated radiation therapy (IMRT) resulted in unacceptable compromise in plan quality and delivery efficiency. We introduce a novel fluence map segmentation method based on compressed sensing for plan delivery using a simplified sparse orthogonal collimator (SOC) on the 4π non-coplanar radiotherapy platform. Methods: 4π plans with varying prescription doses were first created by automatically selecting and optimizing 20 non-coplanar beams for 2 GBM, 2 head & neck, and 2 lung patients. To create deliverable 4π plans using SOC, which are two pairs of orthogonal collimators with 1 to 4 leaves in each collimator bank, a Haar Fluence Optimization (HFO) method was used to regulate the number of Haar wavelet coefficients while maximizing the dose fidelity to the ideal prescription. The plans were directly stratified utilizing the optimized Haar wavelet rectangular basis. A matching number of deliverable segments were stratified for the MLC-based plans. Results: Compared to the MLC-based 4π plans, the SOC-based 4π plans increased the average PTV dose homogeneity from 0.811 to 0.913. PTV D98 and D99 were improved by 3.53% and 5.60% of the corresponding prescription doses. The average mean and maximal OAR doses slightly increased by 0.57% and 2.57% of the prescription doses. The average number of segments ranged between 5 and 30 per beam. The collimator travel time to create the segments decreased with increasing leaf numbers in the SOC. The two and four leaf designs were 1.71 and 1.93 times more efficient, on average, than the single leaf design. Conclusion: The innovative dose domain optimization based on compressed sensing enables uncompromised 4π non-coplanar IMRT dose delivery using simple rectangular segments that are deliverable using a sparse orthogonal collimator, which only requires 8 to 16 leaves yet is unlimited in modulation resolution. This work is

  1. Effect of intrafractional prostate motion on simultaneous boost intensity-modulated radiotherapy to the prostate: a simulation study based on intrafractional motion in the prone position.

    Science.gov (United States)

    Ikeda, Itaru; Mizowaki, Takashi; Ono, Tomohiro; Yamada, Masahiro; Nakamura, Mitsuhiro; Monzen, Hajime; Yano, Shinsuke; Hiraoka, Masahiro

    2015-01-01

    Although the prostate displacement of patients in the prone position is affected by respiration-induced motion, the effect of intrafractional prostate motion in the prone position during "simultaneous integrated boost intensity-modulated radiotherapy" (SIB-IMRT) is unclear. The purpose of this study was to evaluate the dosimetric effects of intrafractional motion on SIB-IMRT to a dominant intraprostatic lesion (IPL) using measured motion data of patients in a prone position, fixed with a thermoplastic shell. We obtained 2 orthogonal x-ray fluoroscopic images at the same moment every 0.2 seconds for 30 seconds before and after treatment, once weekly, from 7 patients with localized prostate cancer with detectable prostatic calcification. Prostate displacements in the left-right (LR), anteroposterior (AP), and superoinferior (SI) directions were calculated using the prostatic calcification as a fiducial marker. We defined the displacement between pretreatment and posttreatment as baseline drift (BD). An SIB-IMRT plan was generated in which each IPL + 3mm received a dose of 94.5Gy, whereas the remainder of the prostate + 7mm received a dose of 75.6Gy in 9 fields. A simulated plan of dose blurring was generated by the convolution of isocenter-shifted plans using measured motion data in 30 seconds and motion in 30 seconds + distance between pretreatment and posttreatment position (BD) for each of the 7 patients. The motion in 30 seconds mainly reflected respiration-induced motion. The mean displacements of BD were 1.4mm (- 3.1 to 8.2mm), - 2.2mm (- 9.1 to 1.5mm), and - 0.3mm (- 5.0 to 1.8mm) in the AP, SI, and LR directions, respectively. The differences in the target coverage with V90% of the IPL and V100% of the prostate between the simulated plan and original plan were - 3.9% to - 0.3% and - 0.6% to 1.1% for respiration-induced motion and 3.1% to - 67.8% and 3.6% to - 13.3% for BD with respiration-induced motion, respectively. The large motion of BD resulted in an

  2. SU-E-P-48: Evaluation of Intensity Modulated Radiotherapy (IMRT) with Three Different Commercial Planning Systems for the Treatment of Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D; Chi, Z; Yang, H; Miao, M; Jing, Z [The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei (China)

    2015-06-15

    Purpose: To investigate the performances of three commercial treatment planning systems (TPS) for intensity modulated radiotherapy (IMRT) optimization regarding cervical cancer. Methods: For twenty cervical cancer patients, three IMRT plans were retrospectively re-planned: one with Pinnacle TPS,one with Oncentra TPS and on with Eclipse TPS. The total prescribed dose was 50.4 Gy delivered for PTV and 58.8 Gy for PTVnd by simultaneous integrated boost technique. The treatments were delivered using the Varian 23EX accelerator. All optimization schemes generated clinically acceptable plans. They were evaluated based on target coverage, homogeneity (HI) and conformity (CI). The organs at risk (OARs) were analyzed according to the percent volume under some doses and the maximum doses. The statistical method of the collected data of variance analysis was used to compare the difference among the quality of plans. Results: IMRT with Eclipse provided significant better HI, CI and all the parameters of PTV. However, the trend was not extension to the PTVnd, it was still significant better at mean dose, D50% and D98%, but plans with Oncentra showed significant better in the hight dosage volume, such as maximum dose and D2%. For the bladder wall, there were not notable difference among three groups, although Pinnacle and Oncentra systems provided a little lower dose sparing at V50Gy of bladder and rectal wall and V40Gy of bladder wall, respectively. V40Gy of rectal wall (p=0.037), small intestine (p=0.001 for V30Gy, p=0.010 for maximum dose) and V50Gy of right-femoral head (p=0.019) from Eclipse plans showed significant better than other groups. Conclusion: All SIB-IMRT plans were clinically acceptable which were generated by three commercial TPSs. The plans with Eclipse system showed advantages over the plans with Oncentra and Pinnacle system in the overwhelming majority of the dose coverage for targets and dose sparing of OARs in cervical cancer.

  3. Accelerated partial breast irradiation using intensity-modulated radiotherapy versus whole breast irradiation: 5-year survival analysis of a phase 3 randomised controlled trial.

    Science.gov (United States)

    Livi, Lorenzo; Meattini, Icro; Marrazzo, Livia; Simontacchi, Gabriele; Pallotta, Stefania; Saieva, Calogero; Paiar, Fabiola; Scotti, Vieri; De Luca Cardillo, Carla; Bastiani, Paolo; Orzalesi, Lorenzo; Casella, Donato; Sanchez, Luis; Nori, Jacopo; Fambrini, Massimiliano; Bianchi, Simonetta

    2015-03-01

    Accelerated partial breast irradiation (APBI) has been introduced as an alternative treatment method for selected patients with early stage breast cancer (BC). Intensity-modulated radiotherapy (IMRT) has the theoretical advantage of a further increase in dose conformity compared with three-dimensional techniques, with more normal tissue sparing. The aim of this randomised trial is to compare the local recurrence and survival of APBI using the IMRT technique after breast-conserving surgery to conventional whole-breast irradiation (WBI) in early stage BC. This study was performed at the University of Florence (Florence, Italy). Women aged more than 40years affected by early BC, with a maximum pathological tumour size of 25mm, were randomly assigned in a 1:1 ratio to receive either WBI or APBI using IMRT. Patients in the APBI arm received a total dose of 30 Gy to the tumour bed in five daily fractions. The WBI arm received 50Gy in 25 fractions, followed by a boost on the tumour bed of 10Gy in five fractions. The primary end-point was occurrence of ipsilateral breast tumour recurrences (IBTRs); the main analysis was by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT02104895. A total of 520 patients were randomised (260 to external WBI and 260 to APBI with IMRT) between March 2005 and June 2013. At a median follow-up of 5.0 years (Interquartile Range (IQR) 3.4-7.0), the IBTR rate was 1.5% (three cases) in the APBI group (95% confidence interval (CI) 0.1-3.0) and in the WBI group (three cases; 95% CI 0.0-2.8). No significant difference emerged between the two groups (log rank test p=0.86). We identified seven deaths in the WBI group and only one in the APBI group (p=0.057). The 5-year overall survival was 96.6% for the WBI group and 99.4% for the APBI group. The APBI group presented significantly better results considering acute (p=0.0001), late (p=0.004), and cosmetic outcome (p=0.045). To our knowledge, this is the first randomised

  4. Treatment Plan Technique and Quality for Single-Isocenter Stereotactic Ablative Radiotherapy of Multiple Lung Lesions with Volumetric-Modulated Arc Therapy or Intensity-Modulated Radiosurgery.

    Science.gov (United States)

    Quan, Kimmen; Xu, Karen M; Lalonde, Ron; Horne, Zachary D; Bernard, Mark E; McCoy, Chuck; Clump, David A; Burton, Steven A; Heron, Dwight E

    2015-01-01

    The aim of this study is to provide a practical approach to the planning technique and evaluation of plan quality for the multi-lesion, single-isocenter stereotactic ablative radiotherapy (SABR) of the lung. Eleven patients with two or more lung lesions underwent single-isocenter volumetric-modulated arc therapy (VMAT) radiosurgery or IMRS. All plans were normalized to the target maximum dose. For each plan, all targets were treated to the same dose. Plan conformity and dose gradient were maximized with dose-control tuning structures surrounding targets. For comparison, multi-isocenter plans were retrospectively created for four patients. Conformity index (CI), homogeneity index (HI), gradient index (GI), and gradient distance (GD) were calculated for each plan. V5, V10, and V20 of the lung and organs at risk (OARs) were collected. Treatment time and total monitor units (MUs) were also recorded. One patient had four lesions and the remainder had two lesions. Six patients received VMAT and five patients received intensity-modulated radiosurgery (IMRS). For those treated with VMAT, two patients received 3-arc VMAT and four received 2-arc VMAT. For those treated with IMRS, two patients were treated with 10 and 11 beams, respectively, and the rest received 12 beams. Prescription doses ranged from 30 to 54 Gy in three to five fractions. The median prescribed isodose line was 84% (range: 80-86%). The median maximum dose was 57.1 Gy (range: 35.7-65.1 Gy). The mean combined PTV was 49.57 cm(3) (range: 14.90-87.38 cm(3)). For single-isocenter plans, the median CI was 1.15 (range: 0.97-1.53). The median HI was 1.19 (range: 1.16-1.28). The median GI was 4.60 (range: 4.16-7.37). The median maximum radiation dose (Dmax) to total lung was 55.6 Gy (range: 35.7-62.0 Gy). The median mean radiation dose to the lung (Dmean) was 4.2 Gy (range: 1.1-9.3 Gy). The median lung V5 was 18.7% (range: 3.8-41.3%). There was no significant difference in CI, HI, GI, GD, V5, V10

  5. Dosimetric comparison between intensity-modulated radiotherapy and RapidArc with single arc and dual arc for malignant glioma involving the parietal lobe.

    Science.gov (United States)

    Yuan, Jun; Lei, Mingjun; Yang, Zhen; Fu, Jun; Huo, Lei; Hong, Jidong

    2016-07-01

    The aim of the present study was to evaluate the difference in treatment plan quality, monitor units (MUs) per fraction and dosimetric parameters between IMRT (intensity-modulated radiotherapy) and RapidArc with single arc (RA1) and dual arc (RA2) for malignant glioma involving the parietal lobe. Treatment plans for IMRT and RA1 and RA2 were prepared for 10 patients with malignant gliomas involving the parietal lobe. The Wilcoxon matched-pair signed-rank test was used to compare the plan quality, monitor units and dosimetric parameters between IMRT and RA1 and RA2 through dose-volume histograms. Dnear-max (D2%) to the left lens, right lens and left optical nerve in RA1 were less compared with those in IMRT; D2% to the right lens and right optic nerve in RA2 were less compared with those in IMRT. D2% to the optic chiasma in RA2 was small compared with that in RA1. The median dose (D50%) to the right lens and right optic nerve in RA1 and RA2 was less compared with the identical parameters in IMRT, and D50% to the brain stem in RA2 was less compared with that in RA1. The volume receiving at least 45 Gy (V45) or V50 in normal brain tissue (whole brain minus the planning target volume 2; B-P) in RA1 was less compared with that in IMRT. V30, V35, V40, V45, or V50 in B-P in RA2 was less compared with that in IMRT. The MUs per fraction in RA1 and RA2 were significantly less compared with those in IMRT. All differences with a P-value<0.05 were considered to be significantly different. In conclusion, RA1 and RA2 markedly reduced the MUs per fraction, and spared partial organs at risk and B-P compared with IMRT.

  6. A Treatment Planning and Acute Toxicity Comparison of Two Pelvic Nodal Volume Delineation Techniques and Delivery Comparison of Intensity-Modulated Radiotherapy Versus Volumetric Modulated Arc Therapy for Hypofractionated High-Risk Prostate Cancer Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Myrehaug, Sten [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Chan, Gordon [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Craig, Tim [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Weinberg, Vivian [Biostatistics Core, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA (United States); Cheng, Chun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Roach, Mack [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States); Cheung, Patrick [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Sahgal, Arjun, E-mail: arjun.sahgal@sunnybrook.ca [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada)

    2012-03-15

    Purpose: To perform a comparison of two pelvic lymph node volume delineation strategies used in intensity-modulated radiotherapy (IMRT) for high risk prostate cancer and to determine the role of volumetric modulated arc therapy (VMAT). Methods and Materials: Eighteen consecutive patients accrued to an ongoing clinical trial were identified according to either the nodal contouring strategy as described based on lymphotropic nanoparticle-enhanced magnetic resonance imaging technology (9 patients) or the current Radiation Therapy Oncology Group (RTOG) consensus guidelines (9 patients). Radiation consisted of 45 Gy to prostate, seminal vesicles, and lymph nodes, with a simultaneous integrated boost to the prostate alone, to a total dose of 67.5 Gy delivered in 25 fractions. Prospective acute genitourinary and gastrointestinal toxicities were compared at baseline, during radiotherapy, and 3 months after radiotherapy. Each patient was retrospectively replanned using the opposite method of nodal contouring, and plans were normalized for dosimetric comparison. VMAT plans were also generated according to the RTOG method for comparison. Results: RTOG plans resulted in a significantly lower rate of genitourinary frequency 3 months after treatment. The dosimetric comparison showed that the RTOG plans resulted in both favorable planning target volume (PTV) coverage and lower organs at risk (OARs) and integral (ID) doses. VMAT required two to three arcs to achieve adequate treatment plans, we did not observe consistent dosimetric benefits to either the PTV or the OARs, and a higher ID was observed. However, treatment times were significantly shorter with VMAT. Conclusion: The RTOG guidelines for pelvic nodal volume delineation results in favorable dosimetry and acceptable acute toxicities for both the target and OARs. We are unable to conclude that VMAT provides a benefit compared with IMRT.

  7. MRI-detected skull-base invasion. Prognostic value and therapeutic implication in intensity-modulated radiotherapy treatment for nasopharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yi-Kan; Jiang, Ning; Yue, Dan; Tang, Ling-Long; Zhang, Fan; Lin, Li; Liu, Xu; Chen, Lei; Ma, Jun [Sun Yat-sen University Cancer Center, Department of Radiation Oncology, Guangzhou (China); Liu, Li-Zhi [Sun Yat-sen University Cancer Center, Department of Radiology, Guangzhou (China)

    2014-10-15

    With advances in imaging and radiotherapy, the prognostic value of skull-base invasion in nasopharyngeal carcinoma (NPC) needs to be reassessed. We aimed to define a classification system and evaluate the prognostic value of the classification of magnetic resonance imaging (MRI)-detected skull-base invasion in NPC treated with intensity-modulated radiotherapy (IMRT). We retrospectively reviewed 749 patients who underwent MRI and were subsequently histologically diagnosed with nondisseminated NPC and treated with IMRT. MRI-detected skull-base invasion was not found to be an independent prognostic factor for overall survival (OS), distant metastasis-free survival (DMFS), local relapse-free survival (LRFS), or disease-free survival (DFS; p > 0.05 for all). Skull-base invasion was classified according to the incidence of each site (type I sites inside pharyngobasilar fascia and clivus vs. type II sites outside pharyngobasilar fascia). The 5-year OS, DMFS, LRFS, and DFS rates in the classification of skull-base invasion in NPC were 83 vs. 67 %, 85 vs.75 %, 95 vs. 88 %, and 76 vs. 62 %, respectively (p < 0.05 for all). Multivariate analysis indicated the classification of skull-base invasion was an independent prognostic factor. MRI-detected skull-base invasion is not an independent prognostic factor in patients with NPC treated with IMRT. However, classification according to the site of invasion has prognostic value. Therefore, patients with various subclassifications of stage T3 disease may receive treatment with different intensities; however, further studies are warranted to prove this. (orig.) [German] Aufgrund der Fortschritte der bildgebenden Verfahren und der Strahlentherapie muss der prognostische Wert der Invasion des nasopharyngealen Karzinoms (NPC) in die Schaedelbasis erneut bewertet werden. Unser Ziel ist die Definition eines Klassifikationssystems und die Untersuchung des prognostischen Werts der Klassifikation der MRT-ermittelten Invasion des mit

  8. Late xerostomia after intensity-modulated conformational radiotherapy of upper aero-digestive tract cancers: study 2004-03 by the head and neck oncology and radiotherapy Group (Gortec); Xerostomie tardive apres radiotherapie conformationnelle avec modulation d'intensite des cancers des voies aero-digestives superieures: etude 2004-03 du Groupe oncologie et radiotherapie de la tete et du cou (Gortec)

    Energy Technology Data Exchange (ETDEWEB)

    Toledano, I.; Lapeyre, M. [Centre Jean-Perrin, 63 - Clermont-Ferrand (France); Graff, P. [Centre Alexis-Vautrin, 54 - Vandoeuvre-les-Nancy (France); Serre, C. [Centre Val d' Aurelle, 34 - Montpellier (France); Bensadoun, R.J. [CHU La Miletrie, 86 - Poitiers (France); Bensadoun, R.J.; Ortholan, C. [Centre Antoine-Lacassagne, 06 - Nice (France); Calais, G. [CHU Bretonneau, 37 - Tours (France); Alfonsi, M. [Institut Sainte-Catherine, 84 - Avignon (France); Giraud, P. [Institut Curie, 75 - Paris (France); Hopital europeen Georges-Pompidou, 75 - Paris (France); Racadot, S. [Centre Leon-Berrard, 69 - Lyon (France)

    2010-10-15

    The authors report a retrospective assessment of late xerostomia according to the RTOG (Radiation Therapy Oncology Group) classification of the European Organization for Research and Treatment of Cancer (EORTC) among patients treated by intensity-modulated conformational radiotherapy (IMRT) and suffering from upper aero-digestive tract carcinomas of different stages. Some of these patients have bee operated, and some have been treated by chemotherapy. It appears that the IMRT results in a reduction of late xerostomia, and even in an absence of salivary toxicity. Short communication

  9. Lossless intensity modulation in integrated photonics.

    Science.gov (United States)

    Sandhu, Sunil; Fan, Shanhui

    2012-02-13

    We present a dynamical analysis of lossless intensity modulation in two different ring resonator geometries. In both geometries, we demonstrate modulation schemes that result in a symmetrical output with an infinite on/off ratio. The systems behave as lossless intensity modulators where the time-averaged output optical power is equal to the time-averaged input optical power.

  10. Radiotherapy of intensity modulated VS conformational in the treatment of carcinoma of the prostate. A dosimetric comparison; Radioterapia de intensidad modulada VS conformacional en el tratamiento de carcinoma de prostata. Una camparacion dosimetrica

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Martin, G.; Garcia Vicente, F.; Zapatero Laborda, A.; Bermudez Luna, R.; Roch Gonzalez, M.; Perez Gonzalez, L.; Torres Escobar, J. J.

    2013-07-01

    The intensity modulated (IMRT) radiation therapy is a technique of high conformation which, by its nature, has as one of its main directions prostate cancer radiotherapy treatment. The purpose of this work is presents results of the dosimetric indicators collected in our hospital a number of patients of carcinoma of the prostate with standard three-dimensional Conformal technique (3D-CRT) and IMRT. Aims to demonstrate and quantify with a statistical methodology that, establishing an adequate Protocol of IMRT, significant reductions in risk organ doses can be obtained by keeping the same prescription to the white volume. (Author)

  11. Nasopharynx carcinoma treatment: from the conventional radiotherapy to the conformal radiotherapy with intensity modulation; Traitement du carcinome du nasopharynx: de la radiotherapie conventionnelle a la radiotherapie conformationnelle avec modulation d'intensite

    Energy Technology Data Exchange (ETDEWEB)

    Mokaouim, K.; Grehange, G.; Truc, G.; Peingnaux, K.; Martin, E.; Zanetta, S.; Bruchon, Y.; Bonnetain, F.; Maingon, P. [Centre Georges-Francois Leclerc, 21 - Dijon (France)

    2009-10-15

    The objective of this study was to evaluate retrospectively the impact of factors linked to the radiotherapy realisation on the local and locoregional control, the global survival, the survival without disease of patients suffering of naso-pharynx carcinoma. Conclusion: the patients suffering of a nasopharynx carcinoma treated by irradiation associated to chemotherapy have an improved global survival and an improved survival without disease. The conformal radiotherapy with or without modulated intensity reduce the risk of serous otitis, trismus and xerostomia at long term. It seems necessary to realize multi centric studies with a longer period of follow up before asserting the advantages of the I.M.R.T. in comparison to the classical and conformal technique in the treatment of naso-pharynx carcinomas. (N.C.)

  12. Residual deficits in quality of life one year after intensity-modulated radiotherapy for patients with locally advanced head and neck cancer. Results of a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Tribius, Silke; Raguse, Marieclaire; Voigt, Christian; Petersen, Cordula; Kruell, Andreas [University Medical Center Hamburg-Eppendorf, Department of Radiation Oncology, Hamburg (Germany); Muenscher, Adrian [University Medical Center Hamburg-Eppendorf, Department of Otorhinolaryngology and Head and Neck Surgery, Hamburg (Germany); Groebe, Alexander [University Medical Center Hamburg-Eppendorf, Department of Maxillofacial Surgery, Hamburg (Germany); Bergelt, Corinna [University Medical Center Hamburg-Eppendorf, Department of Medical Psychology, Hamburg (Germany); Singer, Susanne [University Medical Center Mainz, Institute of Medical Biostatistics, Epidemiology and Informatics (IMBEI), Mainz (Germany)

    2015-03-08

    Patients with locally advanced head and neck cancer (LAHNC) undergo life-changing treatments that can seriously affect quality of life (QoL). This prospective study examined the key QoL domains during the first year after intensity-modulated radiotherapy (IMRT) and identified predictors of these changes in order to improve patient outcomes. A consecutive series of patients with LAHNC completed the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core module (QLQ-C30) and the HNC-specific QLQ-HN35 before (t0) and at the end (t1) of definitive or adjuvant IMRT, then at 6-8 weeks (t2), 6 months (t3), and 1 year (t4) after IMRT. Patients (n = 111) completing questionnaires at all five time points were included (baseline response rate: 99 %; dropout rate between t0 and t4: 5 %). QoL deteriorated in all domains during IMRT and improved slowly during the first year thereafter. Many domains recovered to baseline values after 1 year but problems with smelling and tasting, dry mouth, and sticky saliva remained issues at this time. Increases in problems with sticky saliva were greater after 1 year in patients with definitive versus adjuvant IMRT (F = 3.5, P = 0.05). QoL in patients with LAHNC receiving IMRT takes approximately 1 year to return to baseline; some domains remain compromised after 1 year. Although IMRT aims to maintain function and QoL, patients experience long-term dry mouth and sticky saliva, particularly following definitive IMRT. Patients should be counseled at the start of therapy to reduce disappointment with the pace of recovery. (orig.) [German] Die Therapie von Patienten mit lokal fortgeschrittenen Kopf-Hals-Tumoren (LFKHT) geht mit einschneidenden Veraenderungen einher und beeinflusst die Lebensqualitaet (LQ) erheblich. Diese prospektive Studie untersucht die LQ waehrend des ersten Jahres nach intensitaetsmodulierter Strahlentherapie (IMRT) und hat Praediktoren dieser Veraenderungen herausgearbeitet, um

  13. SU-E-T-592: Relationship Between Dose of Distribution and Area of Segment Fields Among Different Intensity-Modulated Radiotherapy Planning in Cervix Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, R; Wang, Y; Cao, Y; Zhang, R; Shang, K; Chi, Z [Hebei Medical University Fourth Hospital, Shijiazhuang, Hebei (China)

    2014-06-01

    Purpose: In premise of uninfluenced to dose distribution of tumor target and organ at risk(OAR) in cervical cancer,area of segment fields was changed to increase efficacy and optimize treatment method by designing different plan of intensity modulated radiotherapy(IMRT). Methods: 12 cases of cervical cancer were confirmed in pathology and treated with step and shoot IMRT. Dose of PTV was 50Gy/25fractions. Every patient was designed 9 treatment plans of IMRT by Pinnacle 8.0m planning system,each plan was used with 9 beams of uniform distribution and fixing incidence direction(200°,240°,280°,320°,0°,40°,80°,120°and 160°respectively),and designed for delivery on Elekta Synergy linear accelerator. All plans were optimized with the direct machine parameter optimization(DMPO) algorithm using the same set of optimization objectives. Number of maximum segment field was defined at 80 and minimum MU in each segment was 5MU,and minimal segment area was 2*1cm{sup 2},2*2cm{sup 2},3*3cm{sup 2},4*4cm{sup 2},5*5cm{sup 2},6*6cm{sup 2},7*7cm{sup 2},8*8cm{sup 2}and 9*9cm{sup 2},respectively.Coverage,homogeneity and conformity of PTV,sparing of OAR, MU and number of segment were compared. Results: In this group, mean volume of PTV was 916.8±228.7 cm{sup 3}. Compared with the area of minimal segment field increased from 2*1cm{sup 2} to 9*9 cm{sup 2},the number of mean MU was decreased from 1405±170 to 490±47 and the number of segment field was reduced from 76±4 to 39±7 respectively(p<0.05). When the limit of minimal segment area was increased from 2*1cm{sup 2} to 7*7 cm{sup 2},dose distribution of PTV,OAR,CI,HI and V{sub 2} {sub 3} were not different (p>0.05),but when the minimal segment area was 8*8 cm{sup 2} and 9*9 cm{sup 2},they were changed compared with 7*7 cm{sup 2} and below(p<0.05). Conclusion: The minimal segment field of IMRT plan designed by Pinnacle 8.0m planning system in cervical carcinoma should be enlarge reasonably and minimal segment area of 7*7 cm

  14. Intensity-modulated radiotherapy for stage IVA/IVB nasopharyngeal carcinoma. Clinical outcomes and patterns of failure in an endemic area in China

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Lei; Tian, Yun-Ming; Sun, Xue-Ming; Huang, Ying; Chen, Chun-Yan; Han, Fei; Liu, Shuai; Lan, Mei; Guan, Ying [Collaborative Innovation Center of Cancer Medicine, State Key Laboratory Oncology in South China, Guangzhou (China); Sun Yat-Sen University Cancer Center, Department of Radiation Oncology, Guangzhou (China); Deng, Xiao-Wu; Lu, Tai-Xiang [Sun Yat-Sen University Cancer Center, Department of Radiation Oncology, Guangzhou (China); Collaborative Innovation Center of Cancer Medicine, State Key Laboratory Oncology in South China, Guangzhou (China)

    2014-11-15

    The purpose of this study was to analyze the mode of relapse patterns and survival of 209 patients with stage IVA and IVB nasopharyngeal carcinoma (NPC). A total of 209 patients who underwent magnetic resonance imaging (MRI) and were subsequently histologically diagnosed with nondisseminated stage IV NPC received intensity-modulated radiotherapy (IMRT) as their primary treatment and were included in this retrospective study. Median follow-up time was 65 months (range, 3-108 months). The 5-year overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) rates for patients with stage IVA and stage IVB NPC were 72.7 vs. 60.0 % (p = 0.319), 62.9 vs. 51.3 % (p = 0.070), 82.9 vs. 93.1 % (p = 0.070), 82.9 vs. 82.9 % (p = 0.897), 76.4 vs. 58.5 % (p = 0.003), respectively. Age older than 44 years was found to be a statistically significant adverse independent prognostic factor for OS. Patients with advanced N status had worse OS, DFS, and DMFS rates. Patients with a primary gross tumor volume (GTV-P) ≥ 55.11 ml had worse OS, DFS, and LRRFS rates. The results of treating stage IVA NPC with IMRT were excellent. Distant metastasis remains the most difficult treatment challenge for patients with stage IVA and IVB NPC, and more effective systemic chemotherapy should be explored. (orig.) [German] Ziel dieser Studie war die Analyse der Rezidivmuster und des Ueberlebens von 209 Patienten mit nasopharyngealem Karzinom (NPC) im Stadium IVA und IVB. Insgesamt 209 Patienten, die mittels MRT und anschliessender histologischer Untersuchung mit nichtdisseminiertem NPC im Stadium IV diagnostiziert worden waren, erhielten eine intensitaetsmodulierte Strahlentherapie (IMRT) als Primaerbehandlung und wurden in diese retrospektive Studie aufgenommen. Die mediane Follow-up-Dauer betrug 65 Monate (Bereich 3-108 Monate). Das 5-Jahres-Gesamtueberleben (OS), das

  15. Intensity-modulated proton therapy, volumetric-modulated arc therapy, and 3D conformal radiotherapy in anaplastic astrocytoma and glioblastoma. A dosimetric comparison

    Energy Technology Data Exchange (ETDEWEB)

    Adeberg, S.; Debus, J. [Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); German Cancer Research Center (DKFZ), Clinical Cooperation Unit Radiation Oncology, Heidelberg (Germany); Harrabi, S.B.; Bougatf, N.; Rieber, J.; Koerber, S.A.; Herfarth, K.; Rieken, S. [Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Bernhardt, D.; Syed, M.; Sprave, T.; Mohr, A. [Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Abdollahi, A. [University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Haberer, T. [Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg (Germany); Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); Combs, S.E. [Technische Universitaet Muenchen, Department of Radiation Oncology, Muenchen (Germany); Helmholtz Zentrum Muenchen, Institut fuer Innovative Radiotherapie (iRT), Department of Radiation Sciences (DRS), Neuherberg (Germany)

    2016-11-15

    The prognosis for high-grade glioma (HGG) patients is poor; thus, treatment-related side effects need to be minimized to conserve quality of life and functionality. Advanced techniques such as proton radiation therapy (PRT) and volumetric-modulated arc therapy (VMAT) may potentially further reduce the frequency and severity of radiogenic impairment. We retrospectively assessed 12 HGG patients who had undergone postoperative intensity-modulated proton therapy (IMPT). VMAT and 3D conformal radiotherapy (3D-CRT) plans were generated and optimized for comparison after contouring crucial neuronal structures important for neurogenesis and neurocognitive function. Integral dose (ID), homogeneity index (HI), and inhomogeneity coefficient (IC) were calculated from dose statistics. Toxicity data were evaluated. Target volume coverage was comparable for all three modalities. Compared to 3D-CRT and VMAT, PRT showed statistically significant reductions (p < 0.05) in mean dose to whole brain (-20.2 %, -22.7 %); supratentorial (-14.2 %, -20,8 %) and infratentorial (-91.0 %, -77.0 %) regions; brainstem (-67.6 %, -28.1 %); pituitary gland (-52.9 %, -52.5 %); contralateral hippocampus (-98.9 %, -98.7 %); and contralateral subventricular zone (-62.7 %, -66.7 %, respectively). Fatigue (91.7 %), radiation dermatitis (75.0 %), focal alopecia (100.0 %), nausea (41.7 %), cephalgia (58.3 %), and transient cerebral edema (16.7 %) were the most common acute toxicities. Essential dose reduction while maintaining equal target volume coverage was observed using PRT, particularly in contralaterally located critical neuronal structures, areas of neurogenesis, and structures of neurocognitive functions. These findings were supported by preliminary clinical results confirming the safety and feasibility of PRT in HGG. (orig.) [German] Die Prognose bei ''High-grade''-Gliomen (HGG) ist infaust. Gerade bei diesen Patienten sollten therapieassoziierte Nebenwirkungen minimiert werden

  16. Potential for reduced radiation-induced toxicity using intensity-modulated arc therapy for whole-brain radiotherapy with hippocampal sparing.

    Science.gov (United States)

    Pokhrel, Damodar; Sood, Sumit; Lominska, Christopher; Kumar, Pravesh; Badkul, Rajeev; Jiang, Hongyu; Wang, Fen

    2015-09-08

    The purpose of this study was to retrospectively investigate the accuracy, plan quality, and efficiency of using intensity-modulated arc therapy (IMAT) for whole brain radiotherapy (WBRT) patients with sparing not only the hippocampus (following RTOG 0933 compliance criteria) but also other organs at risk (OARs). A total of 10 patients previously treated with nonconformal opposed laterals whole-brain radiotherapy (NC-WBRT) were retrospectively replanned for hippocampal sparing using IMAT treatment planning. The hippocampus was volumetrically contoured on fused diagnostic T1-weighted MRI with planning CT images and hippocampus avoidance zone (HAZ) was generated using a 5 mm uniform margin around the hippocampus. Both hippocampi were defined as one paired organ. Whole brain tissue minus HAZ was defined as the whole-brain planning target volume (WB-PTV). Highly conformal IMAT plans were generated in the Eclipse treatment planning system for Novalis TX linear accelerator consisting of high-definition multileaf collimators (HD-MLCs: 2.5 mm leaf width at isocenter) and 6 MV beam for a prescription dose of 30 Gy in 10 fractions following RTOG 0933 dosimetric criteria. Two full coplanar arcs with orbits avoidance sectors were used. In addition to RTOG criteria, doses to other organs at risk (OARs), such as parotid glands, cochlea, external/middle ear canals, skin, scalp, optic pathways, brainstem, and eyes/lens, were also evaluated. Subsequently, dose delivery efficiency and accuracy of each IMAT plan was assessed by delivering quality assurance (QA) plans with a MapCHECK device, recording actual beam-on time and measuring planed vs. measured dose agreement using a gamma index. On IMAT plans, following RTOG 0933 dosimetric criteria, the maximum dose to WB-PTV, mean WB-PTV D2%, and mean WB-PTV D98% were 34.9 ± 0.3 Gy, 33.2 ± 0.4 Gy, and 26.0± 0.4Gy, respectively. Accordingly, WB-PTV received the prescription dose of 30Gy and mean V30 was 90.5% ± 0.5%. The D100%, and

  17. First Clinical Release of an Online, Adaptive, Aperture-Based Image-Guided Radiotherapy Strategy in Intensity-Modulated Radiotherapy to Correct for Inter- and Intrafractional Rotations of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Deutschmann, Heinz, E-mail: h.deutschmann@salk.at [University Clinic for Radiotherapy and Radio-Oncology, Salzburg (Austria); radART Institute for Research and Development of Advanced Radiation Technologies, Paracelsus Medical University, Salzburg (Austria); Kametriser, Gerhard [University Clinic for Radiotherapy and Radio-Oncology, Salzburg (Austria); Steininger, Philipp [radART Institute for Research and Development of Advanced Radiation Technologies, Paracelsus Medical University, Salzburg (Austria); Scherer, Philipp; Schoeller, Helmut [University Clinic for Radiotherapy and Radio-Oncology, Salzburg (Austria); Gaisberger, Christoph [University Clinic for Radiotherapy and Radio-Oncology, Salzburg (Austria); radART Institute for Research and Development of Advanced Radiation Technologies, Paracelsus Medical University, Salzburg (Austria); Mooslechner, Michaela [radART Institute for Research and Development of Advanced Radiation Technologies, Paracelsus Medical University, Salzburg (Austria); Mitterlechner, Bernhard; Weichenberger, Harald [University Clinic for Radiotherapy and Radio-Oncology, Salzburg (Austria); radART Institute for Research and Development of Advanced Radiation Technologies, Paracelsus Medical University, Salzburg (Austria); Fastner, Gert; Wurstbauer, Karl [University Clinic for Radiotherapy and Radio-Oncology, Salzburg (Austria); Jeschke, Stephan [University Clinic for Urology and Andrology, Salzburg (Austria); Forstner, Rosemarie [University Clinic for Radiology, Salzburg (Austria); Sedlmayer, Felix [University Clinic for Radiotherapy and Radio-Oncology, Salzburg (Austria); radART Institute for Research and Development of Advanced Radiation Technologies, Paracelsus Medical University, Salzburg (Austria)

    2012-08-01

    Purpose: We developed and evaluated a correction strategy for prostate rotations using direct adaptation of segments in intensity-modulated radiotherapy (IMRT). Method and Materials: Implanted fiducials (four gold markers) were used to determine interfractional translations, rotations, and dilations of the prostate. We used hybrid imaging: The markers were automatically detected in two pretreatment planar X-ray projections; their actual position in three-dimensional space was reconstructed from these images at first. The structure set comprising prostate, seminal vesicles, and adjacent rectum wall was transformed accordingly in 6 degrees of freedom. Shapes of IMRT segments were geometrically adapted in a class solution forward-planning approach, derived within seconds on-site and treated immediately. Intrafractional movements were followed in MV electronic portal images captured on the fly. Results: In 31 of 39 patients, for 833 of 1013 fractions (supine, flat couch, knee support, comfortably full bladder, empty rectum, no intraprostatic marker migrations >2 mm of more than one marker), the online aperture adaptation allowed safe reduction of margins clinical target volume-planning target volume (prostate) down to 5 mm when only interfractional corrections were applied: Dominant L-R rotations were found to be 5.3 Degree-Sign (mean of means), standard deviation of means {+-}4.9 Degree-Sign , maximum at 30.7 Degree-Sign . Three-dimensional vector translations relative to skin markings were 9.3 {+-} 4.4 mm (maximum, 23.6 mm). Intrafractional movements in 7.7 {+-} 1.5 min (maximum, 15.1 min) between kV imaging and last beam's electronic portal images showed further L-R rotations of 2.5 Degree-Sign {+-} 2.3 Degree-Sign (maximum, 26.9 Degree-Sign ), and three-dimensional vector translations of 3.0 {+-}3.7 mm (maximum, 10.2 mm). Addressing intrafractional errors could further reduce margins to 3 mm. Conclusion: We demonstrated the clinical feasibility of an online

  18. Comparing morbidity and cancer control after 3D-conformal (70/74 Gy) and intensity modulated radiotherapy (78/82 Gy) for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dolezel, Martin [Multiscan Alpha Pardubice Regional Hospital, Oncology Centre, Pardubice (Czech Republic); Charles University in Prague, First Faculty of Medicine, Prague (Czech Republic); Faculty of Medicine and Dentistry, Department of Oncology, Olomouc (Czech Republic); Odrazka, Karel [Multiscan Alpha Pardubice Regional Hospital, Oncology Centre, Pardubice (Czech Republic); Charles University in Prague, First Faculty of Medicine, Prague (Czech Republic); Charles University in Prague, Third Faculty of Medicine, Prague (Czech Republic); Zouhar, Milan; Jansa, Jan; Paluska, Petr [University Hospital Hradec Kralove, Department of Oncology and Radiotherapy, Hradec Kralove (Czech Republic); Vaculikova, Miloslava [Hospital Trutnov, Department of Oncology, Trutnov (Czech Republic); Sefrova, Jana [Hospital Prachatice, Department of Oncology, Prachatice (Czech Republic); Kohlova, Tereza [Proton Therapy Center, Prague (Czech Republic); Vanasek, Jaroslav [Multiscan Alpha Pardubice Regional Hospital, Oncology Centre, Pardubice (Czech Republic); Kovarik, Josef [The Freeman Hospital, Northern Centre for Cancer Care, Newcastle upon Tyne (United Kingdom)

    2015-04-01

    The purpose of this work was to compare toxicity and cancer control between patients with prostate cancer treated using three-dimensional conformal radiotherapy (3D-CRT) and those treated using intensity-modulated radiation therapy (IMRT). A total of 553 patients with prostate cancer were treated with 3D-CRT 70-74 Gy (3D-CRT 70, 3D-CRT 74) or IMRT 78-82 Gy (IMRT 78, IMRT/SIB 82). Late toxicity was scored according to FC-RTOG/LENT criteria. Biochemical failure was defined using the Phoenix and ASTRO definitions. The 5-year risk of grade 2-4 genitourinary toxicity was 26.3 % (3D-CRT 70), 27.2 % (3D-CRT 74), 17.3 % (IMRT 78), and 25.1 % (IMRT/SIB 82) without statistical differences. The 5-year risk of grade 2-4 gastrointestinal toxicity was 19.4 % (3D-CRT 70), 42.1 % (3D-CRT 74), 20.5 % (IMRT 78), and 26.6 % (IMRT/SIB 82). The differences between 3D-CRT 74 and 3D-CRT 70 and between 3D-CRT 74 and IMRT 78 were statistically significant (log rank p = 0.03). The 5-year Phoenix PSA relapse-free survival (PSA-RFS) in low-risk, intermediate-risk, and high-risk patients treated using 3D-CRT were 89.4, 65.5, and 57.8 %, respectively. Patients treated with IMRT achieved the following results: 90.9, 89.4, and 83.9 %. Clinical relapse-free survival (C-RFS) in patients treated using 3D-CRT vs. IMRT for the aforementioned groups were 94.7 vs. 100 %, 86.8 vs. 98.6 %, and 84.4 vs. 94.5 %. Disease-free survival (DFS) for patients treated using 3D-CRT were 83.1, 70.9, and 71.5 %. The IMRT group reached 95.8, 89.1, and 87.6 %. The PSA-RFS for intermediate- and high-risk patients were statistically significant, while C-RFS and DFS were marginally better. Dose escalation with IMRT was associated with improved cancer control in intermediate- and high-risk patients in comparison with 3D-CRT, without compromising toxicity. (orig.) [German] Es erfolgte ein Vergleich von Toxizitaet und Tumorkontrolle bei Patienten mit Prostatakarzinom nach der Behandlung mit dreidimensionaler konformaler

  19. SU-E-P-51: Dosimetric Comparison to Organs at Risk Sparing Using Volumetric-Modulated Arc Therapy Versus Intensity-Modulated Radiotherapy in Postoperative Radiotherapy of Left-Sided Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, L; Deng, G [Department of Oncology, Shandong University School of Medicine, Jinan, Shandong (China); Xie, J; Cheng, J; Liang, N; Zhang, J [Department of Radiation Oncology, Qianfoshan Hospital Affiliated to Shandon, Jinan, Shandong (China); Zhang, J; Luo, H [Division of Oncology, Department of Graduate, Weifang Medical College, 2610, Jinan, Shandong (China)

    2015-06-15

    Purpose: To compare the dosimetric characteristics of volumetric-modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) techniques in treatment planning for left-sided breast cancer patients with modified radical mastectomy. Methods: Twenty-four left-sided breast cancer patients treated with modified radical mastectomy were selected in this study. The planning target volume (PTV) was generated by using 7-mm uniform expansion of the clinical target volume (CTV) in all direction except the skin surface. The organs at risk (OARs) included heart, left lung, right lung, and right breast. Dose volume histograms (DVHs) were utilized to evaluate the dose distribution in PTV and OARs. Results: Both VMAT and IMRT plans met the requirement of PTV coverage. VMAT was superior to IMRT in terms of conformity, with a statistically significant difference (p=0.024). Mean doses, V5 and V10 of heart and both lungs in VMAT plans were significantly decreased compared to IMRT plans (P<0.05), but in terms of heart volume irradiated by high doses (V30 and V45), no significant differences were observed (P>0.05). For right breast, VMAT showed the reduction of V5 in comparison with IMRT (P<0.05). Additionally, the mean number of monitor units (MU) and treatment time in VMAT (357.21, 3.62 min) were significantly less than those in IMRT (1132.85, 8.74 min). Conclusion: VMAT showed similar PTV coverage and significant advantage in OARs sparing compared with IMRT, especially in terms of decreased volumes irradiated by low doses, while significantly reducing the treatment time and MU number.

  20. 宫颈癌术后常规与旋转容积调强放疗计划剂量学研究%Dosimetric study of conventional intensity-modulated radiotherapy and volumetric intensity-modulated arc radiotherapy for postoperation of cervix cancer

    Institute of Scientific and Technical Information of China (English)

    李军; 陈雪梅; 张西志; 张先稳; 花威; 汤晓斌; 柴磊; 陈达

    2014-01-01

    目的:比较研究宫颈癌常规调强放疗(conventional intensity-modulated radiotherapy,C-IMRT)与旋转容积调强放疗(volumetric intensity-modulated arc therapy,VMAT)计划对靶区及其周围危及器官受照剂量的差异.方法:随机选择2012-08-01-2013-05-31苏北人民医院收治的12例宫颈癌术后患者,进行CT模拟定位、靶区和危及器官的勾画,在同一CT图像上用治疗计划系统进行C-IMRT和VMAT计划设计,处方剂量均为CTV 50 Gy,分25次,危及器官限量参考临床要求.在95%体积的PTV达到处方剂量的条件下,比较2种计划的剂量体积直方图,靶区、危及器官、靶区剂量适形度、剂量分布均匀性、机器跳数(monitor unit,MU)和治疗时间.对治疗计划结果采用配对t检验分析方法评价各指标的差异性.结果:VMAT计划与C-IMRT计划相比,膀胱的Dmean和V20两者差异无统计学意义,P>0.05;D50、V30和V40均明显降低(P<0.05),且直肠的D5和小肠的D1也明显降低(P<0.05),其他的危及器官的剂量学参数均没有明显降低.正常组织V10 VMAT计划明显高于C-IMRT计划(P<0.05),而V30VMAT计划明显低于C-IMRT计划,P<0.05.VMAT计划相比于C-IMRT计划MU平均减少了50.7%;出束时间T减少了47.2%.结论:在宫颈癌术后放疗中,VMAT技术较C-IMRT技术有剂量学方面的优势,患者的治疗时间和机器跳数MU显著降低,在综合条件允许的情况下可推荐使用VMAT技术.

  1. Prospective evaluation of a hydrogel spacer for rectal separation in dose-escalated intensity-modulated radiotherapy for clinically localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Eckert Franziska

    2013-01-01

    Full Text Available Abstract Background As dose-escalation in prostate cancer radiotherapy improves cure rates, a major concern is rectal toxicity. We prospectively assessed an innovative approach of hydrogel injection between prostate and rectum to reduce the radiation dose to the rectum and thus side effects in dose-escalated prostate radiotherapy. Methods Acute toxicity and planning parameters were prospectively evaluated in patients with T1-2 N0 M0 prostate cancer receiving dose-escalated radiotherapy after injection of a hydrogel spacer. Before and after hydrogel injection, we performed MRI scans for anatomical assessment of rectal separation. Radiotherapy was planned and administered to 78 Gy in 39 fractions. Results From eleven patients scheduled for spacer injection the procedure could be performed in ten. In one patient hydrodissection of the Denonvillier space was not possible. Radiation treatment planning showed low rectal doses despite dose-escalation to the target. In accordance with this, acute rectal toxicity was mild without grade 2 events and there was complete resolution within four to twelve weeks. Conclusions This prospective study suggests that hydrogel injection is feasible and may prevent rectal toxicity in dose-escalated radiotherapy of prostate cancer. Further evaluation is necessary including the definition of patients who might benefit from this approach. Trial registration: German Clinical Trials Register DRKS00003273.

  2. Comparison of the dose distribution obtained from dosimetric systems with intensity modulated radiotherapy planning system in the treatment of prostate cancer

    Science.gov (United States)

    Gökçe, M.; Uslu, D. Koçyiǧit; Ertunç, C.; Karalı, T.

    2016-03-01

    The aim of this study is to compare Intensity Modulated Radiation Therapy (IMRT) plan of prostate cancer patients with different dose verification systems in dosimetric aspects and to compare these systems with each other in terms of reliability, applicability and application time. Dosimetric control processes of IMRT plan of three prostate cancer patients were carried out using thermoluminescent dosimeter (TLD), ion chamber (IC) and 2D Array detector systems. The difference between the dose values obtained from the dosimetric systems and treatment planning system (TPS) were found to be about % 5. For the measured (TLD) and calculated (TPS) doses %3 percentage differences were obtained for the points close to center while percentage differences increased at the field edges. It was found that TLD and IC measurements will increase the precision and reliability of the results of 2D Array.

  3. SU-E-T-810: Volumetric Modulated Arc Therapy and Conventional Intensity-Modulated Radiotherapy for Non-Small-Cell Lung Cancer with Simultaneously Integrated Boost Radiation Therapy: A Planning Comparison Study

    Energy Technology Data Exchange (ETDEWEB)

    Liu, T; Chen, J; Zhang, G; Sun, T [Shandong Tumor Hospital, Jinan, Shandong (China)

    2015-06-15

    Purpose: To compare and analyze the characteristics of intensity-modulated arc therapy(IMAT) versus fixed-gantry intensity-modulated radiotherapy(IMRT) in treatment of non-small-cell lung cancer. Methods: Twelve patients treated in our radiotherapy center were selected for this study. The patient subsequently underwent 4D-CT simulation.Margins of 5mm and 10mm were added to the ITV to generate the CTV and PTV respectively. Three treatment plans (IMRT,one single arc (RA1),double arcs (RA2))were generated with Eclipse ver.8.6 planning systems. Using a dose level of 75Gy in 15fractions to the ITV,60Gy in 15fractions to the CTV and 45Gy in 15fractions to the PTV respectively. The target and normol tissue volumes were compared,as were the dosimetry parameters. Results: There were no significant differences in CI of ITV,PTV,HI of ITV,CTV and PTV, V5,V10,V15,V20,V25,V30,V45,V50 of total-lung and mean lung dose (all p>0.05). However, the differences were significant in terms of CI of CTV,V5 of B-P (all p<0.05). On the MU, IMRT=1540MU,RA1=1006 MU and RA2=1096 MU. (F=12.00,P=0.000).On the treatment time, IMRT= 13.5min,RA1= 1.5min,and RA2=2.5 min (F= 30.11,P=0.000 ). Conclusion: IMAT is equal to IMRT in dosimetril evaluation. Due to much less Mu and delivery time,IMAT is an ideal technique in treating patients by reduceing the uncomfortable influnce which could effect the treatment.

  4. Swallowing sparing intensity modulated radiotherapy (SW-IMRT) in head and neck cancer : Clinical validation according to the model-based approach

    NARCIS (Netherlands)

    Christianen, Miranda E. M. C.; van der Schaaf, Arjen; van der Laan, Hans Paul; Verdonck-de Leeuw, Irma M.; Doornaert, Patricia; Chouvalova, Olga; Steenbakkers, Roel J. H. M.; Leemans, Charles Rene; Oosting, Sjoukje F.; van der Laan, Bernard F. A. M.; Roodenburg, Jan L. N.; Slotman, Ben J.; Bijl, Hendrik P.; Langendijk, Johannes A.

    2016-01-01

    Purpose: The aim of this study was to clinically validate a multivariable normal tissue complication probability (NTCP) model for grade 2-4 swallowing dysfunction at 6 months after radiotherapy or chemoradiation (SWAL(M6)) in head and neck cancer patients treated with swallowing sparing intensity mo

  5. Recurrences after intensity modulated radiotherapy for head and neck squamous cell carcinoma more likely to originate from regions with high baseline [18F]-FDG uptake

    DEFF Research Database (Denmark)

    Due, Anne Kirkebjerg; Vogelius, Ivan Richter; Aznar, Marianne;

    2014-01-01

    received radiotherapy for HNSCC from 2005 to 2009. Among 100 patients achieving complete clinical response and a later recurrence, 39 patients with 48 loco-regional failures had a recurrence CT scan before any salvage therapy. The estimated point of origin of each recurrence was transferred to the planning...

  6. Early injure of intensity-modulated radiotherapy in middle or lower esophageal carcinoma on heart%中下段食管癌适形调强放疗对心脏的早期损害

    Institute of Scientific and Technical Information of China (English)

    郭兆娇; 杨林

    2015-01-01

    目的:探讨中下段食管癌适形调强放射治疗(IMRT)对心脏的近期损害。方法选择20例经病理证实的中下段食管癌患者进行根治性适形调强放疗,分别于放疗前1周和放疗后1周行心电图、心肌酶谱、肌钙蛋白、超声心动图检查。结果放疗前后血清乳酸脱氢酶(LDH)、谷丙转氨酶(ALT)、谷草转氨酶(AST)、磷酸激酶(CK)、磷酸激酶同工酶(CK-MB)、超敏肌钙蛋白(cTnI)变化不明显(P>0.05);放疗后心电图异常率大于放疗前,差异有统计学意义(P<0.05);放疗前后LA、LVD、LVEF变化不明显(P>0.05)。结论中下段食管癌放疗引起或诱发的早期心肌损伤不明显,主要表现在心电图的改变,而心肌酶谱、肌钙蛋白、超声心动图等相关指标改变不明显。%ObjectiveTo investigate the recent influence of intensity-modulated radiotherapy (IMRT) in middle or lower esophageal carcinoma on heart. Methods20 patients confirmed esophageal carcinoma under paragraph radical conformal IMRT were selected, respectively, received electrocardiogram, myocardial enzymes, troponin, echocardiography in the week before radiotherapy and radiotherapy week. Results The serum lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), kinase (CK), kinase isoenzyme (CK-MB), high-sensitivity troponin (cTnI) before and after radiotherapy was not changed significantly (P>0.05); the former was greater than the rate of ECG abnormalities after radiotherapy radiotherapy, the difference was statistically significant (P0.05). ConclusionLower esophageal radiotherapy-induced or induced myocardial injury early is not obvious, mainly in the ECG changes, and myocardial enzymes, troponin, echocardiography and other related indicators change is not obvious.

  7. Treatment Plan Technique and Quality for Single-Isocenter Stereotactic Ablative Radiotherapy of Multiple Lung Lesions with Volumetric-Modulated Arc Therapy or Intensity-Modulated Radiosurgery

    OpenAIRE

    Quan, Kimmen; Xu, Karen M.; Lalonde, Ron; Horne, Zachary D.; BERNARD, MARK E.; McCoy, Chuck; Clump, David A.; Steven A Burton; Dwight E Heron

    2015-01-01

    The aim of this study is to provide a practical approach to the planning technique and evaluation of plan quality for the multi-lesion, single-isocenter stereotactic ablative radiotherapy (SABR) of the lung. Eleven patients with two or more lung lesions underwent single-isocenter volumetric-modulated arc therapy (VMAT) radiosurgery or IMRS. All plans were normalized to the target maximum dose. For each plan, all targets were treated to the same dose. Plan conformity and dose gradient were max...

  8. Treatment plan technique and quality for single-isocenter stereotactic ablative radiotherapy of multiple lung lesions with volumetric modulated arc therapy or intensity-modulated radiosurgery

    OpenAIRE

    Kimmen eQuan; Karen Mann Xu; Ron eLalonde; Horne, Zachary D.; BERNARD, MARK E.; Chuck eMcCoy; David Anthony Clump; Steven eBurton; Dwight E Heron

    2015-01-01

    Purpose: The aim is to provide a practical approach to the planning technique and evaluation of plan quality for the multi-lesion, single-isocenter stereotactic ablative radiotherapy (SABR) of the lung. Methods and Materials: Eleven patients with 2 or more lung lesions underwent single-isocenter VMAT radiosurgery or IMRS. All plans were normalized to the target maximum dose. For each plan, all targets were treated to the same dose. Plan conformity and dose gradient were maximized with dose...

  9. Hypofractionated helical intensity-modulated radiotherapy of the prostate bed after prostatectomy with or without the pelvic lymph nodes - the PRIAMOS trial

    Directory of Open Access Journals (Sweden)

    Krause Sonja

    2012-10-01

    Full Text Available Abstract Background While evidence on safety and efficacy of primary hypofractionated radiotherapy in prostate cancer is accumulating, data on postoperative hypofractionated treatment of the prostate bed and of the pelvic lymph nodes is still scarce. This phase II trial was initiated to investigate safety and feasibility of hypofractionated treatment of the prostate bed alone or with the pelvic lymph nodes. Methods/design A total of 80 prostate cancer patients with the indication for adjuvant radiotherapy will be enrolled, where 40 patients with a low risk of lymph node involvement (arm 1 and another 40 patients with a high risk of lymph node involvement (arm 2 will each receive 54 Gy in 18 fractions to the prostate bed. Arm 2 will be given 45 Gy to the pelvic lymph nodes additionally. Helical Tomotherapy and daily image guidance will be used. Discussion This trial was initiated to substantiate data on hypofractionated treatment of the prostate bed and generate first data on adjuvant hypofractionated radiotherapy of the pelvic lymph nodes. Trial registration ClinicalTrials.gov; NCT01620710

  10. Breath-hold technique in conventional APPA or intensity-modulated radiotherapy for Hodgkin's lymphoma. Comparison of ILROG IS-RT and the GHSG IF-RT

    Energy Technology Data Exchange (ETDEWEB)

    Kriz, Jan; Spickermann, Max; Lehrich, Philipp; Reinartz, Gabriele; Eich, Hans; Haverkamp, Uwe [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Schmidberger, Heinz [University Mainz, Department of Radiation Oncology, Mainz (Germany)

    2015-09-15

    The present study addresses the role of intensity-modulated radiotherapy (IMRT) in contrast to standard RT (APPA) for patients with Hodgkin's lymphoma (HL) with a focus on deep inspiration breath-hold (DIBH) technique and a comparison between the International Lymphoma Radiation Oncology Group (ILROG) Involved Site Radiotherapy (IS-RT) versus the German Hodgkin Study Group (GHSG) Involved Field Radiotherapy (IF-RT). APPA treatment and 2 IMRT plans were compared for 11 patients with HL. Furthermore, treatment with DIBH versus free breathing (FB) and two different treatment volumes, i.e. IF-RT versus IS-RT, were compared. IMRT was planned as a sliding-window technique with 5 and 7 beam angles. For each patient 12 different treatment plans were calculated (132 plans). Following organs at risk (OAR) were analysed: lung, heart, spinal cord, oesophagus, female breast and skin. Comparisons of the different values with regard to dose-volume histograms (DVH), conformity and homogeneity indices were made. IS-RT reduces treatment volumes. With respect to the planning target volume (PTV), IMRT achieves better conformity but the same homogeneity. Regarding the D{sub mean} for the lung, IMRT shows increased doses, while RT in DIBH reduces doses. The IMRT shows improved values for D{sub max} concerning the spinal cord, whereas the APPA shows an improved D{sub mean} of the lung and the female breast. IS-RT reduces treatment volumes. Intensity-modulated radiotherapy shows advantages in the conformity. Treatment in DIBH also reduces the dose applied to the lungs and the heart. (orig.) [German] Ziel dieser Auswertung ist es, die konventionelle APPA-Feldanordnung mit der Intensitaetsmodulierten Radiotherapie (IMRT) bei Patienten mit Hodgkin-Lymphom (HL) zu vergleichen. Ein besonderer Fokus liegt hierbei auf der Bestrahlung in tiefer Inspiration und Atemanhaltetechnik (DIBH). Des Weiteren wurde die ''Involved-site''-Radiotherapie (IS-RT) der International

  11. The correlation between the comprehensive nutrition index and quality of life of patients with nasopharyngeal carcinoma treated by intensity-modulated radiotherapy.

    Science.gov (United States)

    Ma, Liqin; Wu, Tingting; Pan, Jianji; Kong, Xiangquan; Guo, Qiaojuan; Yang, Ling; Zhang, Yu; Lin, Shaojun; Chen, Chuanben; Huang, Chaobin

    2014-01-01

    The purpose of this study was to compare the changing tendency of nutrition with 54 nasopharyngeal carcinoma patients during intensity-modulated radiation therapy (IMRT), and to investigate the correlation between comprehensive nutritional status and quality of life (QoL), which was assessed by the European Organization for Research and Treatment of Cancer Core Quality-of-Life Questionnaire. The nutritional index, including body mass index, ideal body weight percentage, usual body weight percentage, albumin, hemoglobin, and total lymphocyte count (TLC), was evaluated at 2 time points: within 48 h after admission (T1) and at the end of treatment with IMRT (T2). A statistically significant downgrade of every index was observed during IMRT. A comprehensive nutritional model was established by principal components analysis at T2. QoL scores of functional (P = 0.002) and the global QoL scales (P = 0.001) existed a positive correlation with comprehensive nutritional status. QoL scores of symptom scales (P = 0.002) and 6 single items (P = 0.005) had a negative correlation with it. The scores of global QoL scales in comprehensive nutrition of normal (20.4%), moderate (55.6%), and severe malnutrition (24.1%) were 69.70 ± 17.98, 48.33 ± 19.25, and 37.18 ± 24.67, respectively. Patients with different nutritional status had different QoL (B = 10.405, SE = 2.828, t = 3.680, P = 0.001). Multiaspect nutritional supports should be enhanced to improve patients' comprehensive nutritional status during treatment.

  12. Simultaneous integrated boost radiotherapy for bilateral breast: a treatment planning and dosimetric comparison for volumetric modulated arc and fixed field intensity modulated therapy

    Directory of Open Access Journals (Sweden)

    Vanetti Eugenio

    2009-07-01

    Full Text Available Abstract Purpose A study was performed comparing dosimetric characteristics of volumetric modulated arcs (RapidArc, RA and fixed field intensity modulated therapy (IMRT on patients with bilateral breast carcinoma. Materials and methods Plans for IMRT and RA, were optimised for 10 patients prescribing 50 Gy to the breast (PTVII, 2.0 Gy/fraction and 60 Gy to the tumour bed (PTVI, 2.4 Gy/fraction. Objectives were: for PTVs V90%>95%, Dmax20 Gy Results For PTVII minus PTVI, V90% was 97.8 ± 3.4% for RA and 94.0 ± 3.5% for IMRT (findings are reported as mean ± 1 standard deviation; D5%-D95% (homogeneity was 7.3 ± 1.4 Gy (RA and 11.0 ± 1.1 Gy (IMRT. Conformity index (V95%/VPTVII was 1.10 ± 0.06 (RA and 1.14 ± 0.09 (IMRT. MLD was 20 Gy was 9.7 ± 1.3% (RA and 12.8 ± 2.5% (IMRT on left lung, similar for right lung. Mean dose to heart was 6.0 ± 2.7 Gy (RA and 7.4 ± 2.5 Gy (IMRT. MU resulted in 796 ± 121 (RA and 1398 ± 301 (IMRT; the average measured treatment time was 3.0 ± 0.1 minutes (RA and 11.5 ± 2.0 (IMRT. From pre-treatment dosimetry, % of field area with γ Conclusion RapidArc showed dosimetric improvements with respect to IMRT, delivery parameters confirmed its logistical advantages, pre-treatment dosimetry proved its reliability.

  13. Simultaneous integrated boost radiotherapy for bilateral breast: a treatment planning and dosimetric comparison for volumetric modulated arc and fixed field intensity modulated therapy

    Science.gov (United States)

    Nicolini, Giorgia; Clivio, Alessandro; Fogliata, Antonella; Vanetti, Eugenio; Cozzi, Luca

    2009-01-01

    Purpose A study was performed comparing dosimetric characteristics of volumetric modulated arcs (RapidArc, RA) and fixed field intensity modulated therapy (IMRT) on patients with bilateral breast carcinoma. Materials and methods Plans for IMRT and RA, were optimised for 10 patients prescribing 50 Gy to the breast (PTVII, 2.0 Gy/fraction) and 60 Gy to the tumour bed (PTVI, 2.4 Gy/fraction). Objectives were: for PTVs V90%>95%, Dmax<107%; Mean lung dose MLD<15 Gy, V20 Gy<22%; heart involvement was to be minimised. The MU and delivery time measured treatment efficiency. Pre-treatment dosimetry was performed using EPID and a 2D-array based methods. Results For PTVII minus PTVI, V90% was 97.8 ± 3.4% for RA and 94.0 ± 3.5% for IMRT (findings are reported as mean ± 1 standard deviation); D5%-D95% (homogeneity) was 7.3 ± 1.4 Gy (RA) and 11.0 ± 1.1 Gy (IMRT). Conformity index (V95%/VPTVII) was 1.10 ± 0.06 (RA) and 1.14 ± 0.09 (IMRT). MLD was <9.5 Gy for all cases on each lung, V20 Gy was 9.7 ± 1.3% (RA) and 12.8 ± 2.5% (IMRT) on left lung, similar for right lung. Mean dose to heart was 6.0 ± 2.7 Gy (RA) and 7.4 ± 2.5 Gy (IMRT). MU resulted in 796 ± 121 (RA) and 1398 ± 301 (IMRT); the average measured treatment time was 3.0 ± 0.1 minutes (RA) and 11.5 ± 2.0 (IMRT). From pre-treatment dosimetry, % of field area with γ <1 resulted 98.8 ± 1.3% and 99.1 ± 1.5% for RA and IMRT respectively with EPID and 99.1 ± 1.8% and 99.5 ± 1.3% with 2D-array (ΔD = 3% and DTA = 3 mm). Conclusion RapidArc showed dosimetric improvements with respect to IMRT, delivery parameters confirmed its logistical advantages, pre-treatment dosimetry proved its reliability. PMID:19630947

  14. Phase II study of induction chemotherapy with TPF followed by radioimmunotherapy with Cetuximab and intensity-modulated radiotherapy (IMRT in combination with a carbon ion boost for locally advanced tumours of the oro-, hypopharynx and larynx - TPF-C-HIT

    Directory of Open Access Journals (Sweden)

    Mavtratzas Athanasios

    2011-05-01

    Full Text Available Abstract Background Long-term locoregional control in locally advanced squamous cell carcinoma of the head and neck (SCCHN remains challenging. While recent years have seen various approaches to improve outcome by intensification of treatment schedules through introduction of novel induction and combination chemotherapy regimen and altered fractionation regimen, patient tolerance to higher treatment intensities is limited by accompanying side-effects. Combined radioimmunotherapy with cetuximab as well as modern radiotherapy techniques such as intensity-modulated radiotherapy (IMRT and carbon ion therapy (C12 are able to limit toxicity while maintaining treatment effects. In order to achieve maximum efficacy with yet acceptable toxicity, this sequential phase II trial combines induction chemotherapy with docetaxel, cisplatin, and 5-FU (TPF followed by radioimmunotherapy with cetuximab as IMRT plus carbon ion boost. We expect this approach to result in increased cure rates with yet manageable accompanying toxicity. Methods/design The TPF-C-HIT trial is a prospective, mono-centric, open-label, non-randomized phase II trial evaluating efficacy and toxicity of the combined treatment with IMRT/carbon ion boost and weekly cetuximab in 50 patients with histologically proven locally advanced SCCHN following TPF induction chemotherapy. Patients receive 24 GyE carbon ions (8 fractions and 50 Gy IMRT (2.0 Gy/fraction in combination with weekly cetuximab throughout radiotherapy. Primary endpoint is locoregional control at 12 months, secondary endpoints are disease-free survival, progression-free survival, overall survival, acute and late radiation effects as well as any adverse events of the treatment as well as quality of life (QoL analyses. Discussion The primary objective of TPF-C-HIT is to evaluate efficacy and toxicity of cetuximab in combination with combined IMRT/carbon ion therapy following TPF induction in locally advanced SCCHN. Trial Registration

  15. Dosimetric comparison of intensity modulated radiotherapy, volumetric-modulated arc therapy and tomotherapy in patients with gastric adenocarcinoma after curative surgery

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Objective:To compare the dosimetric differences between IMRT, VMAT and TOMO planning for gastric cancer patients.Methods: A total of 14 patients with gastric cancer after curative surgery were prospectively enrolled. In each case, IMRT, VMAT and TOMO plans were created (45Gy/25f). Dose distributions and dose–volume histograms for PTV and normal tissue were compared. A paired t test or signed-rank test was applied to compare the averages between techniques.Results:Comparison of the PTV revealed satisfactory coverage by the 95% isodose envelope in three plans. However, significantly higher conformity index (CI) and lower V20 of bone marrow were observed in TOMO plan. Moreover, IMRT and TOMO techniques both showed signiifcant reduced mean dose of the bilateral lungs compared to the VMAT. Not much difference was found in parameters of the kidney, intestine, spine, liver and heart.Conclusion:The IMRT, VMAT and TOMO plans all achieved favorable target coverage and dose sparing of the critical organs in adjuvant radiotherapy for gastric cancer. However, the TOMO technique displayed the best target dose conformity and superior sparing of the bone marrow and lungs.

  16. CIM—Compact intensity modulation

    Science.gov (United States)

    Bleuel, M.; Lang, E.; Gähler, R.; Lal, J.

    2008-07-01

    Compact intensity modulation (CIM), a new method to modulate the intensity of a neutron beam is demonstrated. CIM allows the production of arbitrary signals where the focus point can be chosen and changed without any constraints. A novel feature in this technique compared to spin echo techniques is that the neutron polarization is kept parallel or anti-parallel to the static fields during the passage through the magnetic fields and the beating pattern at the detector is produced by an amplitude modulation (AM) of the adiabatic RF-spin flippers rather than Larmor precession like in neutron spin echo (NSE) instruments; thus, the achievable contrast is very high and the instrument resolution can be changed very quickly. This gives the fascinating possibility at pulsed neutron sources to sweep the modulation frequency of the flippers in order to increase dynamic resolution range during the same neutron pulse.

  17. Comparison of intensity-modulated radiotherapy with conventional conformal radiotherapy for postoperative retroperitoneal soft tissue; Etude theorique d'une radiotherapie postoperatoire avec modulation d'intensite d'un sarcome retroperitoneal

    Energy Technology Data Exchange (ETDEWEB)

    Musat, E.; Kantor, G.; Caron, J.; Lagarde, P.; Laharie, H.; Angles, J.; Gilbeau, L. [Centre Regional de Lutte Contre le Cancer, Institut Bergonie, Dept. de Radiotherapie, 33 - Bordeaux (France); Stoeckle, E. [Centre Regional de Lutte Contre le Cancer, Institut Bergonie, Dept. de Chirurgie, 33 - Bordeaux (France); Bui, B.N. [Centre Regional de Lutte Contre le Cancer, Institut Bergonie, Dept. de Medecine, 33 - Bordeaux (France)

    2004-08-01

    External postoperative radiation therapy for retroperitoneal sarcoma is an example of treatment using large fields for complex shaped volumes of irradiation, Prescribed dose is limited by tolerance of adjacent organs at risk (OAR). From a recent case treated by conventional conformal radiotherapy (3D-CRT), we evaluate the benefit of five theoretical IMRT plans. Criteria used are calculated from DVH related to delineated PTV and OAR, IMRT should permit to enhance the prescribed dose without increasing dose in the OAR (especially residual kidney, spinal cord and small bowel). This theoretical study show the feasibility of a dose escalation from a treatment dose of 45 Gy delivered by 3D-CRT up to a planning dose of 54 Gy calculated by IMRT with: - for the PTV: an improvement of the dose homogeneity about 5% (range 2 %) and moreover the coverage factor (CF) about 13% (range 9 6%); - for the OAR: an improvement of the protection factor (PF) about 20% (range 11-24%); - and thus an improved conformity index (CI = CF x PF) about 25% (range 15-32%). (author)

  18. 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.

  19. 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.

  20. 调强适形放疗在乳腺癌保乳术后应用的系统评价%Intensity-modulated radiotherapy for breast cancer: a systematic review

    Institute of Scientific and Technical Information of China (English)

    Xiupeng Ye; Liyun Guo; Ruifeng Liu; Shifang Feng; Ling Su; Xiaohu Wang; Kehu Yang; Jinhui Tian; Qiuning Zhang; Qiang Wang; Xiaojun Li; Yuqing Kang

    2010-01-01

    Objective: The aim of this study was to assess the long-term effect of breast conservation with breast intensity-modulated radiotherapy (IMRT) for early-stage breast cancers. Methods: Pub Med, EMBASE, Cochrane Library, Chinese Biomedical Literature Database were searched to identify relevant original published trails, and the references of eligible studies were manually screened. Randomized controlled trails reported in any language, comparing breast IMRT with conventional radiotherapy (RT) in patients with early-stage breast cancer were eligible for inclusion. Two investigators independently assessed the quality of included trials and extracted data. The RevMan 5.0 software was used for statistical analysis. Results: Four trials involving 1440 patients were included. The results showed that in the IMRT group, the occurrence of acute moist dermatitis, the edema of the mammary gland and the occurrence of hyperpigmentation were lower than those of RT group, the pooled risk ratio value and 95% confidence interval were 0.28 (0.17-0.48), 0.03 (0.00-0.21) and 0.06 (0.02-0.15) respectively. The use of IMRT did not correlate with pain and quality of life, but the presence of moist desquamation did significantly correlate with pain and reduced quality of life. Conclusion: The currently available evidence showed that IMRT significantly reduces the occurrence of moist acute dermatitis anywhere in the breast and alleviates the suffering of patients and improves the quality of life of patients. Future large-scale, high-quality, double-blind trials are needed.

  1. SU-E-T-198: Hippocampal-Sparing Radiotherapy (HSRT) for Patients with Head and Neck Cancer (HNC) Using Intensity-Modulated Radiation Therapy (IMRT)

    Energy Technology Data Exchange (ETDEWEB)

    Dunlop, A; Welsh, L; Nutting, C; Harrington, K; Bhide, S; Newbold, K

    2014-06-01

    Purpose: There is increasing evidence that decline in cognitive function following brain radiotherapy (RT) is related to the radiation dose delivered to the hippocampi. In this work we evaluate the feasibility of using IMRT to generate HSRT plans in HNC. Methods: A planning study was undertaken for ten representative patients with HNC previously treated with radical (chemo)-RT using standard IMRT techniques. The hippocampi were delineated according to the RTOG hippocampal contouring atlas, on a T1w- MRI scan that was registered with the RT planning CT. LINAC-based, clinically acceptable, HSRT plans were generated and assessed using the Pinnacle3 treatment planning system. Results: Using a VMAT technique, a reduction in hippocampal dose was achievable in six cases. For these cases, the EQD2-D40% of the bilateral hippocampi was significantly reduced by HSRT (p = 0.006) from a median of 18.8Gy (range 14.4–34.6) to 6.5 Gy (4.2–9.5) for the delivered and HSRT plans respectively. Plans were also generated using a fixed-field IMRT technique with non-coplanar beams that were designed to avoid the bilateral hippocampi, resulting in a median EQD2-D40% of 11.2Gy (8.0–14.5). Both HSRT techniques also resulted in lower doses to the whole brain, brain stem, and cerebellum. The HSRT plans resulted in higher doses to some regions of non-contoured normaltissue, but the magnitude of these dose differences is unlikely to be of clinical significance in terms of acute and late toxicity. Conclusion: This study has demonstrated that it is possible, in many cases, to adapt treatment plans for HNC to significantly reduce dose to the hippocampi. This reduction in dose would be predicted to Resultin a significant reduction in the probability of subsequent decline in cognitive function following RT. Our results point towards the need for the collection of prospective data on cognitive outcomes for the HNC patient population treated with radical (chemo)-RT.

  2. Comparison between nedaplatin and cisplatin plus docetaxel combined with intensity-modulated radiotherapy for locoregionally advanced nasopharyngeal carcinoma: a multicenter randomized phase II clinical trial

    Science.gov (United States)

    Tang, Chunyuan; Wu, Fang; Wang, Rensheng; Lu, Heming; Li, Guisheng; Liu, Meilian; Zhu, Haisheng; Zhu, Jinxian; Zhang, Yong; Hu, Kai

    2016-01-01

    Nasopharyngeal carcinoma (NPC) is highly incident in southern China. Metastasis is the major cause of death in NPC patients. Concurrent chemoradiotherapy (CCRT) has been accepted as standard in the treatment of patients with locoregionally advanced nasopharyngeal carcinoma (NPC). However, induction chemotherapy (IC) also has benefits in this disease, especially in the patients with certain high-risk factors such as bulky and/or extensive nodal disease. It has been presented that adding IC to CCRT might be a reasonable approach and need more work to confirm. The optimal chemotherapeutic regimen combined with radiotherapy has not been determined so far. It is important to explore high effective and low toxic chemotherapy for the patients. In the multicenter prospective study, 223 patients with locoregionally advanced untreated NPC were randomized into experimental group and control group. The patients received two cycles of induction chemotherapy (IC) with docetaxel (DOC) plus nedaplatin (NDP) in experimental group every 3 weeks, followed by IMRT concurrent with weekly NDP for six cycles, and NDP was replaced by cisplatin (CDDP) in control group. More patients in experimental group could receive full courses of IC and concurrent chemoradiotherapy (CCRT) (P=0.013). There was no significant difference between the two groups in the percentage of reduction of GTVnx and GTVnd after IC (P=0.207 and P=0.107) and CR rate three months after completion of chemoradiotherapy (P=0.565 and P=0.738). With a mean follow-up of 35.1 months, no statistically significant difference in the 3-year OS, LRFS, RRFS, DMFS, and PFS was found. During IC, more patients suffered vomiting in control group (P=0.001). During CCRT, grade 3/4 neutropenia/thrombocytopenia were more common in experimental group (P=0.028 and P=0.035); whereas, severe anemia and vomiting were more common in control group (P=0.0001 and P=0.023). In conclusions, patients with locoregionally advanced NPC showed good

  3. Treatment plan technique and quality for single-isocenter stereotactic ablative radiotherapy of multiple lung lesions with volumetric modulated arc therapy or intensity-modulated radiosurgery

    Directory of Open Access Journals (Sweden)

    Kimmen eQuan

    2015-10-01

    Full Text Available Purpose: The aim is to provide a practical approach to the planning technique and evaluation of plan quality for the multi-lesion, single-isocenter stereotactic ablative radiotherapy (SABR of the lung. Methods and Materials: Eleven patients with 2 or more lung lesions underwent single-isocenter VMAT radiosurgery or IMRS. All plans were normalized to the target maximum dose. For each plan, all targets were treated to the same dose. Plan conformity and dose gradient were maximized with dose control tuning structures surrounding targets. For comparison, multi-isocenter plans were retrospectively created for 4 patients. Conformity index (CI, homogeneity index (HI, gradient index (GI and gradient distance (GD were calculated for each plan. V5, V10, and V20 of the lung and organs at risk (OARs were collected. Treatment time and total monitor units (MUs were also recorded. Results: One patient had 4 lesions and the remainder had 2 lesions. Six patients received VMAT and 5 patients received IMRS. For those treated with VMAT, two patients received 3-arc VMAT and four received 2-arc VMAT. For those treated with IMRS, two patients were treated with 10 and 11 beams, respectively, and the rest received 12 beams. Prescription doses ranged from 30 to 54 Gy in 3 to 5 fractions. The median prescribed isodose line was 84% (range: 80-86%. The median maximum dose was 57.1 Gy (range: 35.7-65.1 Gy. The mean combined PTV was 49.57 cm3 (range: 14.90 - 87.38 cm3. For single-isocenter plans, the median CI was 1.15 (range: 0.97-1.53. The median HI was 1.19 (range: 1.16-1.28. The median GI was 4.60 (range: 4.16-7.37. The median maximum radiation dose (Dmax to total lung was 55.6 Gy (range: 35.7-62.0 Gy. The median mean radiation dose to the lung (Dmean was 4.2 Gy (range: 1.1-9.3 Gy. The median lung V5 was 18.7% (range: 3.8-41.3%. There was no significant difference in CI, HI, GI, GD, V5, V10 and V20 (lung, heart, trachea, esophagus, and spinal cord between single

  4. SU-E-T-272: Radiation Damage Comparison Between Intensity Modulated Radiotherapy and Field-In-Field Technique in Breast Cancer Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Ai, H [IU School of Medicine, Indianapolis, IN (United States); Zhang, H [Northwestern Memorial Hospital, Chicago, IL (United States)

    2014-06-01

    Purpose: To compare normal tissue complications between IMRT and FIF treatment in breast cancer. Methods: 16 patients treated with IMRT plan and 20 patients treated with FIF plan were evaluated in this study. Both kinds of plans were generated using Eclipse treatment planning system by dosimetrist following clinical radiotherapy treatment guidelines. The plans were reviewed and approved by radiation oncologist. The average survival fraction (SF) for three different normal tissue cells of each concerned structure can be calculated from differential dose volume histogram (DVH) using linear quadratic model. The three types of normal tissues include radiosensitive, moderately radiosensitive and radio-resistant that represents 70%, 50% and 30% survival fractions, respectively, for a 2-Gy open field. Equivalent uniform doses (EUD) for corresponding normal tissues of each structure were calculated. Results: The EUDs of the lungs, heart, healthy breast and spinal cord with both IMRT and FIF treatments were calculated. Considering the average value of all IMRT plans, the lung of treated side absorbed 16.0% of dosage prescribed to the tumor if the radiosensitivity of the lung is similar to the radiosensitive cell line. For moderately radiosensitive and radio-resistant lung tissue, the average EUDs can be 18.9% and 22.4% of prescription. In contrast, patients treated with FIF plans were delivered 6.0%, 7.5% and 10.3% of prescribed dose for radiosensitive, moderately radiosensitive and radio-resistant lung tissue, respectively. Comparing heart EUDs between IMRT and FIF plans, average absorbed doses in IMRT treatment were 7.7%, 8.7% and 9.7% of prescription for three types of heart normal tissue cell lines while FIF treatments delivered only 1.3%, 1.5% and 1.6% of prescription dose. For the other organs, the results were similar. Conclusion: The results indicated that breast cancer treatment using IMRT technique had more normal tissue damage than FIF treatment. FIF demonstrated

  5. Image-guided intensity-modulated radiotherapy for refractory bilateral breast cancer in a patient with extensive cutaneous metastasis in the chest and abdominal walls

    Directory of Open Access Journals (Sweden)

    Lu YF

    2016-05-01

    Full Text Available Yueh-Feng Lu,1 Yu-Chin Lin,2 Kuo-Hsin Chen,3,4 Pei-Wei Shueng,1 Hsin-Pei Yeh,1 Chen-Hsi Hsieh1,5,6 1Division of Radiation Oncology, Department of Radiology, 2Division of Oncology and Hematology, Department of Medicine, 3Department of Surgery, Far Eastern Memorial Hospital, New Taipei City, 4Department of Electrical Engineering, Yuan-Ze University, Taoyuan, 5Department of Medicine, 6Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan Abstract: Treatment for bilateral breast cancer with chest wall and abdominal skin invasion normally involves conventional radiotherapy (RT; however, conventional RT provides inadequate target volume coverage and excessive treatment of large volumes of normal tissue. Helical tomotherapy (HT has the ability to deliver continuous craniocaudal irradiation that suppresses junction problems and provides good conformity of dose distribution. A 47-year-old female with stage IV bilateral breast cancer with chest wall and pectoralis major muscle invasion, lymphadenopathy, bilateral pleural effusion, and multiple bone metastases received chemotherapy and target therapy beginning in January 2014; 4 months after the initiation of chemotherapy, computed tomography revealed progression of chest and abdominal wall invasion. A total dose of 70.2 Gy was delivered to both breasts, the chest wall, the abdominal wall, and the bilateral supraclavicular nodal areas in 39 fractions via HT. The total planning target volume was 4,533.29 cm3. The percent of lung volume receiving at least 20 Gy (V20 was 28%, 22%, and 25% for the right lung, left lung, and whole lung, respectively. The mean dose to the heart was 8.6 Gy. Follow-up computed tomography revealed complete response after the RT course. Grade 1 dysphagia, weight loss, grade 2 neutropenia, and grade 3 dermatitis were noted during the RT course. Pain score decreased from 6 to 1. No cardiac, pulmonary, liver, or intestinal toxicity

  6. Individualized Nonadaptive and Online-Adaptive Intensity-Modulated Radiotherapy Treatment Strategies for Cervical Cancer Patients Based on Pretreatment Acquired Variable Bladder Filling Computed Tomography Scans

    Energy Technology Data Exchange (ETDEWEB)

    Bondar, M.L., E-mail: m.bondar@erasmusmc.nl [Department of Radiation Oncology, Erasmus-MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Hoogeman, M.S.; Mens, J.W.; Quint, S. [Department of Radiation Oncology, Erasmus-MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Ahmad, R. [Department of Radiation Oncology, Erasmus-MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Programme of Diagnostic Imaging and Radiotherapy, University Kebangsaan Malaysia (Malaysia); Dhawtal, G.; Heijmen, B.J. [Department of Radiation Oncology, Erasmus-MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2012-08-01

    bladder and rectum inside the PTV (0% to 10% and -1% to 9%; p < 0.004) and the CTV-to-PTV volume (4-96 ml). Conclusions: Compared with population-based margins, an individualized PTV results in better organ-at-risk sparing. Online-adaptive radiotherapy further improves organ-at-risk sparing.

  7. Interfraction rotation of the prostate as evaluated by kilovoltage X-ray fiducial marker imaging in intensity-modulated radiotherapy of localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Graf, Reinhold; Boehmer, Dirk; Budach, Volker [Charite Universitaetsmedizin Berlin, Department of Radiation Oncology, Campus Virchow-Klinikum, Berlin (Germany); Wust, Peter, E-mail: peter.wust@charite.de [Charite Universitaetsmedizin Berlin, Department of Radiation Oncology, Campus Virchow-Klinikum, Berlin (Germany)

    2012-01-01

    To quantify the daily rotation of the prostate during a radiotherapy course using stereoscopic kilovoltage (kV) x-ray imaging and intraprostatic fiducials for localization and positioning correction. From 2005 to 2009, radio-opaque fiducial markers were inserted into 38 patients via perineum into the prostate. The ExacTrac/Novalis Body X-ray 6-day image acquisition system (ET/NB; BrainLab AG, Feldkirchen, Germany) was used to determine and correct the target position. During the first period in 10 patients we recorded all rotation errors but used only Y (table) for correction. For the next 28 patients we used for correction all rotational coordinates, i.e., in addition Z (superior-inferior [SI] or roll) and X (left-right [LR] or tilt/pitch) according to the fiducial marker position by use of the Robotic Tilt Module and Varian Exact Couch. Rotation correction was applied above a threshold of 1 Degree-Sign displacement. The systematic and random errors were specified. Overall, 993 software-assisted rotational corrections were performed. The interfraction rotation errors of the prostate as assessed from the radiodense surrogate markers around the three axes Y, Z, and X were on average 0.09, -0.52, and -0.01 Degree-Sign with standard deviations of 2.01, 2.30, and 3.95 Degree-Sign , respectively. The systematic uncertainty per patient for prostate rotation was estimated with 2.30, 1.56, and 4.13 Degree-Sign and the mean random components with 1.81, 2.02, and 3.09 Degree-Sign . The largest rotational errors occurred around the X-axis (pitch), but without preferring a certain orientation. Although the error around Z (roll) can be compensated on average by a transformation with 4 coordinates, a significant error around X remains and advocates the full correction with 6 coordinates. Rotational errors as assessed via daily stereoscopic online imaging are significant and dominate around X. Rotation possibly degrades the dosimetric coverage of the target volume and may require

  8. 宫颈癌术后骨髓保护调强放疗研究%Bone marrow-sparing intensity-modulated radiotherapy for postoperative treatment of cervical cancer

    Institute of Scientific and Technical Information of China (English)

    Fuli Zhang; Mingmin Zheng; Junmao Gao; Weidong Xu

    2011-01-01

    Objective: The aim of this study was to compare bone marrow-sparing intensity-modulated radiotherapy (IMRT)with IMRT without entering pelvic bone marrow as a planning constraint in the treatment of cervical cancer after hysterectomy. Methods: For a cohort of 10 patients, bone marrow-sparing IMRT and routine IMRT planning were designed. Theproscribed dose was 45 Gy/1.8 Gy/25f, 95% of the planning target volume received this dose. Doses were computed with a commercially available treatment planning system (TPS) using convolution/superimposition (CS) algorithm. Plans were compared according to dose-volume histogram (DVH) analysis in terms of planning target volume (PTV) homogeneity and conformity indices (HI and CI) as well as organs at risk (OARs) dose and volume parameters. Results: Bone marrow-sparing IMRT had an vantages over routine IMRT in terms of CI, but inferior to the latter for HI. Compared with routine IMRT, V5,V10, V20, V30, V40 of pelvic bone marrow of bone marrow-sparing IMRT reduced by 1.81%, 8.61%, 31.81%, 29.50%, 28.29%,respectively. No statistically significant differences were observed between bone marrow-sparing IMRT and routine IMRT in terms of small bowel, bladder and rectum. Conclusion: For patients with cervical cancer after hysterectomy, bone marrowsparing IMRT reduced the pelvic bone marrow volume irradiated at all dose levels and might be conducive to preventing the occurrence of acute bone marrow toxicity.

  9. 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.

  10. Elevated plasma fibrinogen level shows superior prognostic value than Epstein-Barr virus DNA load for stage IVA/B nasopharyngeal carcinoma patients in the intensity-modulated radiotherapy era.

    Science.gov (United States)

    Lan, Mei; Chen, Chunyan; Huang, Ying; Mao, Minjie; Han, Fei; Liao, Junfang; Deng, Meiling; Duan, Zhijun; Zheng, Lie; Wu, Shaoxiong; Lu, Taixiang; Jian, Yutao

    2016-07-19

    Effective prognostic factors for patients with stage IVA/B nasopharyngeal carcinoma (NPC) who are susceptible to distant metastases are limited. We aim to investigate the prognostic value of pretreatment plasma fibrinogen (FIB) level and Epstein-Barr virus DNA (EBV-DNA) load in these patients in the era of intensity-modulated radiotherapy (IMRT). The 5-year DSS, DFS and DMFS rates of the entire cohort were 72.7%, 66.8%, 80.0%, respectively. High FIB level was identified as a negative prognostic factor for survival: the 5-year DSS, DFS and DMFS rates for patients with high FIB (> 4.0 g/L) and normal FIB (≤ 4.0 g/L) were 60.3% vs. 76.0%, 56.0% vs. 69.9%, and 59.4% vs. 85.5%, respectively (all P level shows superior prognostic value than EBV-DNA load for stage IVA/B NPC patients in the era of IMRT. A total of 755 patients with newly-diagnosed stage IVA/B NPC treated with definitive IMRT between January 2007 and December 2011 were enrolled. Plasma FIB and EBV-DNA were measured before treatment. Disease-specific survival (DSS), disease-free survival (DFS) and distant metastasis-free survival (DMFS) were calculated using the Kaplan-Meier method; differences were compared using the log-rank test.

  11. A comparison of volumetric modulated arc therapy and sliding-window intensity-modulated radiotherapy in the treatment of Stage I-II nasal natural killer/T-cell lymphoma.

    Science.gov (United States)

    Liu, Xianfeng; Yang, Yong; Jin, Fu; He, Yanan; Zhong, Mingsong; Luo, Huanli; Qiu, Da; Li, Chao; Yang, Han; He, Guanglei; Wang, Ying

    2016-01-01

    This article is aimed to compare the dosimetric differences between volumetric modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for Stage I-II nasal natural killer/T-cell lymphoma (NNKTL). Ten patients with Stage I-II NNKTL treated with IMRT were replanned with VMAT (2 arcs). The prescribed dose of the planning target volume (PTV) was 50Gy in 25 fractions. The VMAT plans with the Anisotropic Analytical Algorithm (Version 8.6.15) were based on an Eclipse treatment planning system; the monitor units (MUs) and treatment time (T) were scored to measure the expected treatment efficiency. All the 10 patients under the study were subject to comparisons regarding the quality of target coverage, the efficiency of delivery, and the exposure of normal adjacent organs at risk (OARs). The study shows that VMAT was associated with a better conformal index (CI) and homogeneity index (HI) (both p delivery time. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  12. Hypoxia imaging with [18F]-FMISO-PET for guided dose escalation with intensity-modulated radiotherapy in head-and-neck cancers

    Energy Technology Data Exchange (ETDEWEB)

    Henriques de Figueiredo, B. [Institut Bergonie, Department of Radiotherapy, Bordeaux (France); INCIA UMR-CNRS 5287, Bordeaux (France); Zacharatou, C. [Institut Bergonie, Department of Radiotherapy, Bordeaux (France); Galland-Girodet, S.; Benech, J. [Hospital Haut-Leveque, Department of Radiotherapy, CHRU Bordeaux (France); Clermont-Gallerande, H. de [Hospital Pellegrin, Department of Nuclear Medicine, CHRU Bordeaux (France); Lamare, F. [INCIA UMR-CNRS 5287, Bordeaux (France); Hospital Haut-Leveque, Department of Radiotherapy, CHRU Bordeaux (France); Hatt, M. [LaTIM INSERM U1101, Brest (France); Digue, L. [Hospital Saint-Andre, Department of Clinical Oncology, CHRU Bordeaux (France); Mones del Pujol, E. de [Department of Oto-rhino-laryngology, CHRU Bordeaux (France); Fernandez, P. [INCIA UMR-CNRS 5287, Bordeaux (France); Hospital Pellegrin, Department of Nuclear Medicine, CHRU Bordeaux (France); University Bordeaux 2, Bordeaux (France)

    2014-09-23

    Positron emission tomography (PET) with [{sup 18}F]-fluoromisonidazole ([{sup 18}F]-FMISO) provides a non-invasive assessment of hypoxia. The aim of this study is to assess the feasibility of a dose escalation with volumetric modulated arc therapy (VMAT) guided by [{sup 18}F]-FMISO-PET for head-and-neck cancers (HNC). Ten patients with inoperable stages III-IV HNC underwent [{sup 18}F]-FMISO-PET before radiotherapy. Hypoxic target volumes (HTV) were segmented automatically by using the fuzzy locally adaptive Bayesian method. Retrospectively, two VMAT plans were generated delivering 70 Gy to the gross tumour volume (GTV) defined on computed tomography simulation or 79.8 Gy to the HTV. A dosimetric comparison was performed, based on calculations of tumour control probability (TCP), normal tissue complication probability (NTCP) for the parotid glands and uncomplicated tumour control probability (UTCP). The mean hypoxic fraction, defined as the ratio between the HTV and the GTV, was 0.18. The mean average dose for both parotids was 22.7 Gy and 25.5 Gy without and with dose escalation respectively. FMISO-guided dose escalation led to a mean increase of TCP, NTCP for both parotids and UTCP by 18.1, 4.6 and 8 % respectively. A dose escalation up to 79.8 Gy guided by [{sup 18}F]-FMISO-PET with VMAT seems feasible with improvement of TCP and without excessive increase of NTCP for parotids. (orig.) [German] Die Positronenemissionstomographie (PET) mit [{sup 18}F]-Fluoromisonidazol ([{sup 18}F]-FMISO) ermoeglicht eine nichtinvasive Beurteilung der Hypoxie. Ziel dieser Studie ist es, die Durchfuehrbarkeit einer [{sup 18}F]-FMISO-PET-gefuehrten Dosissteigerung bei volumetrisch modulierter Arc-Therapie (VMAT) von Kopf-Hals-Tumoren (KHT) zu bewerten. Zehn Patienten mit inoperablen KHT der Stadien III-IV erhielten vor der Strahlentherapie eine [{sup 18}F]-FMISO-PET. Hypoxische Zielvolumina (HV) wurden automatisch mit Hilfe des FLAB(Fuzzy Locally Adaptive Bayesian

  13. 早期乳腺癌保乳术后大分割调强放疗美容效果的临床研究%Results of Clinical Studies on Hypofractionation Intensity-Modulated Radiotherapy in Patients with Early-Stage Breast Cancer after Breast-Conserving Surgery

    Institute of Scientific and Technical Information of China (English)

    吕春燕; 郝福荣; 刘杰; 姜迎宵; 马瑞忠; 王明臣

    2013-01-01

    目的:观察早期乳腺癌保乳术后大分割调强放疗( h-IMRT)的美容效果。方法收集潍坊市人民医院2009年2月~2013年1月67例女性早期乳腺癌保乳术后患者,根据患者意愿入组三维适形放疗(3DCRT)、常规分割调强放疗(IMRT)或h-IMRT组。3DCRT组:采用6MV-X线切线野照射,全乳腺50Gy/25次/5周,然后行瘤床区9/12 MeV电子线补量10 Gy/5 F/1周;IMRT组:采用逆向动态调强技术,全乳腺50 Gy/25次/5周,瘤床区用X线同步加量60Gy/25次/5周,或全乳腺放疗结束后行电子线补量(方式及剂量同3DCRT);h-IM-RT组:全乳腺42.5Gy/16F/22d,瘤床区同步加量48Gy/16F/22d。结果短期随访结果示,早期乳腺癌保乳术后患者大分割调强放疗组可以明显缩短放疗时间,未降低美容效果,未增加局部复发风险。结论大分割IMRT很有可能成为中国女性早期乳腺癌保乳术后安全有效的放疗模式。%Objective To observe short-term cosmetic outcome of hypofractionated intensity-modulated ra-diotherapy ( h-IMRT) in patients with early-stage breast cancer after breast-conserving surgery .Methods Sixty-seven women cases with early-stage breast cancer after breast-conserving were collected in Weifang People's Hospital from Feb-ruary 2009 to January 2013,and divided into three group:three-dimensional conformal radiotherapy (3DCRT),the con-ventional fractioned intensity modulated radiotherapy ( IMRT) ,and the hypofractionated intensity-modulated radiotherapy (h-IMRT) according to the patient's attention.For 3DCRT and IMRT group,the whole affected-side breast was delivered 5 days a week to a dose of 50 Gy in 25 fractions using 6 MV photons adopting tangential field irradiation or reverse dy-namic intensity modulated technology respectively , then tumor bed ( the lumpectomy site with a 1 ~2 cm margin or the breast scars with a 2~3cm margin) was boosted by 9/12MeV electron beam to a dose of 10Gy 5 days a

  14. How diffusivity, thermocline and incident light intensity modulate the dynamics of deep chlorophyll maximum in Tyrrhenian Sea.

    Science.gov (United States)

    Valenti, Davide; Denaro, Giovanni; Spagnolo, Bernardo; Conversano, Fabio; Brunet, Christophe

    2015-01-01

    During the last few years theoretical works have shed new light and proposed new hypotheses on the mechanisms which regulate the spatio-temporal behaviour of phytoplankton communities in marine pelagic ecosystems. Despite this, relevant physical and biological issues, such as effects of the time-dependent mixing in the upper layer, competition between groups, and dynamics of non-stationary deep chlorophyll maxima, are still open questions. In this work, we analyze the spatio-temporal behaviour of five phytoplankton populations in a real marine ecosystem by using a one-dimensional reaction-diffusion-taxis model. The study is performed, taking into account the seasonal variations of environmental variables, such as light intensity, thickness of upper mixed layer and profiles of vertical turbulent diffusivity, obtained starting from experimental findings. Theoretical distributions of phytoplankton cell concentration was converted in chlorophyll concentration, and compared with the experimental profiles measured in a site of the Tyrrhenian Sea at four different times (seasons) of the year, during four different oceanographic cruises. As a result we find a good agreement between theoretical and experimental distributions of chlorophyll concentration. In particular, theoretical results reveal that the seasonal changes of environmental variables play a key role in the phytoplankton distribution and determine the properties of the deep chlorophyll maximum. This study could be extended to other marine ecosystems to predict future changes in the phytoplankton biomass due to global warming, in view of devising strategies to prevent the decline of the primary production and the consequent decrease of fish species.

  15. 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.

  16. NRG Oncology/RTOG 0921: A phase 2 study of postoperative intensity-modulated radiotherapy with concurrent cisplatin and bevacizumab followed by carboplatin and paclitaxel for patients with endometrial cancer.

    Science.gov (United States)

    Viswanathan, Akila N; Moughan, Jennifer; Miller, Brigitte E; Xiao, Ying; Jhingran, Anuja; Portelance, Lorraine; Bosch, Walter R; Matulonis, Ursula A; Horowitz, Neil S; Mannel, Robert S; Souhami, Luis; Erickson, Beth A; Winter, Kathryn A; Small, William; Gaffney, David K

    2015-07-01

    The current study was conducted to assess acute and late adverse events (AEs), overall survival (OS), pelvic failure, regional failure, distant failure, and disease-free survival in a prospective phase 2 clinical trial of bevacizumab and pelvic intensity-modulated radiotherapy (IMRT) with chemotherapy in patients with high-risk endometrial cancer. Patients underwent a hysterectomy and lymph node removal, and had ≥1 of the following high-risk factors: grade 3 carcinoma with >50% myometrial invasion, grade 2 or 3 disease with any cervical stromal invasion, or known extrauterine extension confined to the pelvis. Treatment included pelvic IMRT and concurrent cisplatin on days 1 and 29 of radiation and bevacizumab (at a dose of 5 mg/kg on days 1, 15, and 29 of radiation) followed by adjuvant carboplatin and paclitaxel for 4 cycles. The primary endpoint was grade ≥3 AEs occurring within the first 90 days (toxicity was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]). A total of 34 patients were accrued from November 2009 through December 2011, 30 of whom were eligible and received study treatment. Seven of 30 patients (23.3%; 1-sided 95% confidence interval, 10.6%-36.0%) developed grade ≥3 treatment-related nonhematologic toxicities within 90 days; an additional 6 patients experienced grade ≥3 toxicities between 90 and 365 days after treatment. The 2-year OS rate was 96.7% and the disease-free survival rate was 79.1%. No patient developed a within-field pelvic failure and no patients with International Federation of Gynecology and Obstetrics stage I to IIIA disease developed disease recurrence after a median follow-up of 26 months. Postoperative bevacizumab added to chemotherapy and pelvic IMRT appears to be well tolerated and results in high OS rates at 2 years for patients with high-risk endometrial carcinoma. © 2015 American Cancer Society.

  17. Impact of different leaf velocities and dose rates on the number of monitor units and the dose-volume-histograms using intensity modulated radiotherapy with sliding-window technique

    Directory of Open Access Journals (Sweden)

    Hess Clemens F

    2008-09-01

    Full Text Available Abstract Background Intensity modulated radiotherapy (IMRT using sliding window technique utilises a leaf sequencing algorithm, which takes some control system limitations like dose rates (DR and velocity of the leafs (LV into account. The effect of altering these limitations on the number of monitor units and radiation dose to the organs at risk (OAR were analysed. Methods IMRT plans for different LVs from 1.0 cm/sec to 10.0 cm/sec and different DRs from 100 MU/min to 600 MU/min for two patients with prostate cancer and two patients with squamous cell cancer of the scalp (SCCscalp were calculated using the same "optimal fluence map". For each field the number of monitor units, the dose volume histograms and the differences in the "actual fluence maps" of the fields were analysed. Results With increase of the DR and decrease of the LV the number of monitor units increased and consequentially the radiation dose given to the OAR. In particular the serial OARs of patients with SCCscalp, which are located outside the end position of the leafs and inside the open field, received an additional dose of a higher DR and lower LV is used. Conclusion For best protection of organs at risk, a low DR and high LV should be applied. But the consequence of a low DR is both a long treatment time and also that a LV of higher than 3.0 cm/sec is mechanically not applicable. Our recommendation for an optimisation of the discussed parameters is a leaf velocity of 2.5 cm/sec and a dose rate of 300–400 MU/min (prostate cancer and 100–200 MU/min (SCCscalp for best protection of organs at risk, short treatment time and number of monitor units.

  18. Effects of omitting elective neck irradiation to nodal Level IB in nasopharyngeal carcinoma patients with negative Level IB lymph nodes treated by intensity-modulated radiotherapy: a Phase 2 study.

    Science.gov (United States)

    Li, Mei; Huang, Xiao-Guang; Yang, Zhi-Ning; Lu, Jia-Yang; Zhan, Yi-Zhou; Xie, Wen-Jia; Zhou, Dong-Jie; Wang, Li; Zhu, Di-Xia; Lin, Zhi-Xiong

    2016-09-01

    To investigate the need for elective neck irradiation (ENI) to nodal Level IB in patients with nasopharyngeal carcinoma (NPC) with negative Level IB lymph nodes (IB-negative) treated by intensity-modulated radiotherapy (IMRT). We conducted a Phase 2 prospective study in 123 newly diagnosed IB-negative patients with NPC treated by IMRT, who met at least 1 of the following criteria: (1) unilateral or bilateral Level II involvement with 1 of the following: Level IIA involvement or any Level II node ≥2 cm/with extracapsular spread; (2) ≥2 unilateral node-positive regions. Bilateral Level IB nodes were not contoured as part of the treatment target and treated electively. Level IB regional recurrence rate; pattern of treatment failure; 3-year overall survival (3y-OS), 3-year local control (3y-LC) and 3-year regional control (3y-RC) rates; toxicities; and dosimetric data for planning target volumes, organs at risk, Level IB and submandibular glands (SMGs) were evaluated. Two patients developed failures at Level IB (1.6%). The 3y-LC, 3y-RC and 3y-OS rates were 93.5%, 93.5% and 78.0%, respectively. Bilateral Level IB received unplanned high-dose irradiation with a mean dose (Dmean) ≥50 Gy in 60% of patients. The average Dmean of bilateral SMGs was approximately 53 Gy. ENI to Level IB may be unnecessary in IB-negative patients with NPC treated by IMRT. A further Phase 3 study is warranted. Based on the results of this first Phase 2 study, we suggest omitting ENI to Level IB in Ib-negative patients with NPC with extensive nodal disease treated by IMRT.

  19. Planning analysis for locally advanced lung cancer: dosimetric and efficiency comparisons between intensity-modulated radiotherapy (IMRT, single-arc/partial-arc volumetric modulated arc therapy (SA/PA-VMAT

    Directory of Open Access Journals (Sweden)

    Zhou Xiaojuan

    2011-10-01

    Full Text Available Abstract Purpose To analyze the differences between the intensity-modulated radiotherapy (IMRT, single/partial-arc volumetric modulated arc therapy (SA/PA-VMAT techniques in treatment planning for locally advanced lung cancer. Materials and methods 12 patients were retrospectively studied. In each patient's case, several parameters were analyzed based on the dose-volume histograms (DVH of the IMRT, SA/PA-VMAT plans respectively. Also, each plan was delivered to a phantom for time comparison. Results The SA-VMAT plans showed the superior target dose coverage, although the minimum/mean/maximum doses to the target were similar. For the total and contralateral lungs, the higher V5/10, lower V20/30 and mean lung dose (MLD were observed in the SA/PA-VMAT plans (p 20, V30 and MLD of the controlateral lung more notably, comparing to those parameters of the IMRT and SA-VMAT plans respectively. The delivered monitor units (MUs and treatment times were reduced significantly with VMAT plans, especially PA-VMAT plans (for MUs: mean 458.3 vs. 439.2 vs. 435.7 MUs, p vs. 10.6 vs. 6.4 minutes, p Conclusions The SA-VMAT technique achieves highly conformal dose distribution to the target. Comparing to the IMRT plans, the higher V5/10, lower V20/30 and MLD were observed in the total and contralateral lungs in the VMAT plans, especially in the PA-VMAT plans. The SA/PA-VMAT plans also reduced treatment time with more efficient dose delivering. But the clinical benefit of the VMAT technique for locally advanced lung cancer needs further investigations.

  20. Prognostic Value of Plasma Epstein-Barr Virus DNA for Local and Regionally Advanced Nasopharyngeal Carcinoma Treated With Cisplatin-Based Concurrent Chemoradiotherapy in Intensity-Modulated Radiotherapy Era.

    Science.gov (United States)

    Chen, Wen-Hui; Tang, Lin-Quan; Guo, Shan-Shan; Chen, Qiu-Yan; Zhang, Lu; Liu, Li-Ting; Qian, Chao-Nan; Guo, Xiang; Xie, Dan; Zeng, Mu-Sheng; Mai, Hai-Qiang

    2016-02-01

    This study aimed to evaluate the prognostic value of plasma Epstein-Barr Virus DNA (EBV DNA) for local and regionally advanced nasopharyngeal carcinoma (NPC) patients treated with concurrent chemoradiotherapy in intensity-modulated radiotherapy (IMRT) era.In this observational study, 404 nonmetastatic local and regionally advanced NPC patients treated with IMRT and cisplatin-based concurrent chemotherapy were recruited. Blood samples were collected before treatment for examination of plasma EBV DNA levels. We evaluated the association of pretreatment plasma EBV DNA levels with progression-free survival rate (PFS), distant metastasis-free survival rate (DMFS), and overall survival rate (OS).Compared to patients with an EBV DNA level EBV DNA ≥ 4000  copies/mL had a lower rate of 3-year PFS (76%, 95% CI [68-84]) versus (93%, 95% CI [90-96], P EBV DNA levels (HR = 3.324, 95% CI, 1.80-6.138, P EBV DNA level was the only significant factor to predict DMFS (HR = 6.292, 95% CI, 2.647-14.956, P EBV DNA levels (HR = 3.753, 95% CI, 1.701-8.284, P EBV DNA levels still predicted a worse PFS, DMFS, and OS for the patients stage III or stage IVa-b, compared with those with low EBV DNA levels.Elevated plasma EBV DNA was still effective prognostic biomarker for local and regionally advanced NPC patients treated with IMRT and cisplatin-based concurrent chemotherapy. Future ramdomized clinical trials are needed to further evaluate whether plasma EBV DNA levels could be applied to guide concurrent chemotherapy regimen for local and regionally advanced NPC patients.

  1. SU-E-T-57: A Novel Method to Improve Dose Heterogeneity of Target and Organs at Risk Sparing in the Intensity-Modulated Radiotherapy for Stage III 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: Intensity-modulated radiotherapy (IMRT) treatment for lung cancer is difficult due to the heterogeneous dose distribution and excessive dose to the organs at risk (OARs). We introduce a simple method based on the base dose function (BDF) in Eclipse treatment planning system to overcome the difficulties. Methods: Thirteen patients suffered from stage III non-small cell lung cancer (NSCLC) were enrolled in the study. Three kinds of approaches were applied to obtain clinically acceptable treatment plans: 1) conventionally optimizing method with hot and cold spots re-optimization (CO); 2) target-divided optimizing method (TDO) in which the optimization objective in the lung density of planning target volume (PTV) was set to 2 to 4 Gy higher than in the soft tissue density; 3) base dose function (BDF) in which the treatment plan was produced based on the original plan for re-optimization. CO, TDO and BDF methods were then compared in terms of conformity index (CI), homogeneity index (HI), OARs sparing and monitor units (MUs). Additionally, delta4, portal dosimetry and IMSure were used to measure the dose delivering accuracy. Results: The BDF technique provided more superior CI and HI than the other two methods. Moreover, the new method also reduced the lung, esophagus, heart and spinal cord dose. However, the BDF plans needed extra 15% and 10% MUs than the CO and TDO methods. Dose verification results demonstrated good and comparable γ pass rates among the three methods. Conclusion: The proposed BDF method greatly improves the dose homogeneity and OARs sparing in the IMRT treatment for lung cancer.

  2. A comparison of volumetric modulated arc therapy and sliding-window intensity-modulated radiotherapy in the treatment of Stage I-II nasal natural killer/T-cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianfeng [Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing (China); Yang, Yong [Department of Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Jin, Fu; He, Yanan; Zhong, Mingsong; Luo, Huanli; Qiu, Da; Li, Chao; Yang, Han; He, Guanglei [Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing (China); Wang, Ying, E-mail: zjajf@126.com [Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing (China)

    2016-04-01

    This article is aimed to compare the dosimetric differences between volumetric modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for Stage I-II nasal natural killer/T-cell lymphoma (NNKTL). Ten patients with Stage I-II NNKTL treated with IMRT were replanned with VMAT (2 arcs). The prescribed dose of the planning target volume (PTV) was 50 Gy in 25 fractions. The VMAT plans with the Anisotropic Analytical Algorithm (Version 8.6.15) were based on an Eclipse treatment planning system; the monitor units (MUs) and treatment time (T) were scored to measure the expected treatment efficiency. All the 10 patients under the study were subject to comparisons regarding the quality of target coverage, the efficiency of delivery, and the exposure of normal adjacent organs at risk (OARs). The study shows that VMAT was associated with a better conformal index (CI) and homogeneity index (HI) (both p < 0.05) but slightly higher dose to OARs than IMRT. The MUs with VMAT (650.80 ± 24.59) were fewer than with IMRT (1300.10 ± 57.12) (relative reduction of 49.94%, p = 0.00) when using 2-Gy dose fractions. The treatment time with VMAT (3.20 ± 0.02 minutes) was shorter than with IMRT (7.38 ± 0.18 minutes) (relative reduction of 56.64%, p = 0.00). We found that VMAT and IMRT both provide satisfactory target dosimetric coverage and OARs sparing clinically. Likely to deliver a bit higher dose to OARs, VMAT in comparison with IMRT, is still a better choice for treatment of patients with Stage I-II NNKTL, thanks to better dose distribution, fewer MUs, and shorter delivery time.

  3. Comparison between Electronic Portal Imaging Devices and ion chamber matrix for intensity-modulated radiotherapy quality assurance; Comparacao entre Dispositivos Eletronicos de Imagens Portais e matriz de camaras de ionizacao para garantia da qualidade de radioterapia de intensidade modulada

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Thiago B.; Rosa, Luiz A.R., E-mail: thiago.fisimed@gmail.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Lima, Marilia B., E-mail: thiago.fisimed@gmail.com [Instituto Nacional do Cancer (INCA), Rio de Janeiro, RJ (Brazil). Departamento de Fisica Medica

    2012-08-15

    The treatment with intensity-modulated radiotherapy (IMRT) demands an individual and specific quality assurance procedure. The use of ion chamber matrix is a well establish method to dose distribution verifications, despite the lower spatial resolution. An alternative method arising is the use of the Electronic Portal Imaging Devices (EPIDs). The aim of this paper is to validate the EPID use for quality assurance of IMRT comparing it to the previous method employing an ion chamber matrix. We analyzed 10 treatment planning for different tumor sites and photons energies of the linac Trilogy (Varian Medical Systems). We used Sliding-window IMRT and the measurements were acquired in EPID and in Physikalisch-Technische Werkstaetten (PTW) 2D Array seven29. Two different software were used to analyze the data: Verisoft version 4.0, for Array data; and Eclipse 8.6 with Portal Dosimetry for EPID data. The evaluation of concordance levels between measured and predicted images used the Gamma Index tool with 3% of dose difference and 3 mm of distance to agreement. The EPID showed worse results for approval percentiles, in average 2.17%, and bigger values of average gamma index, although its analysis confirmed the approvals of all planning. This happens because of the better sensitivity generated by the higher spatial resolution of the EPID, 0,784 mm against 1,0 cm of the Array, so it has bigger capacity to identify small dose variations. The EPID, jointly with the Portal Dosimetry, proved to be excellent tools to perform pre-treatment IMRT verifications, providing significant gain in dose distribution analysis. Also, the EPID is easier for positioning, for images manipulation, for data acquisition and analysis and has detection area 60% bigger. (author)

  4. A quantitative comparison of gross tumor volumes delineated on [18F]-FDG-PET/CT scan and contrast-enhanced computed tomography scan in locally advanced head and neck carcinoma treated with Intensity Modulated Radiotherapy

    Directory of Open Access Journals (Sweden)

    Nagarjuna Burela

    2017-05-01

    Full Text Available Accurate tumor diagnosis is important in highly conformal techniques such as Intensity Modulated Radiotherapy (IMRT, which aims for high therapeutic ratio. We compared Gross Tumor Volume (GTV (primary and nodal delineated on 18F-fluorodeoxyglucose positron emission tomography ([18F]-FDG-PET scan to those delineated on contrast-enhanced computed tomography (CECT scan and its impact on staging treated by IMRT. A total of 30 consecutive patients with locally advanced squamous cell carcinoma of head and neck were included in this study. FDG-PET and CECT scans were performed with dedicated positron emission tomography–computed tomography (PET/CT scanner in a single session as part of radiotherapy treatment planning for IMRT. After treatment with concurrent chemoradiotherapy, all patients were followed for one year. Three out of 30 patients were excluded from the final analysis, as there was complete remission in PET/CT after neoadjuvant chemotherapy. For remaining 27 cases, the primary sites were 17 oropharynx, 2 hypopharynx, 7 larynx and 1 unknown primary with secondary neck node. PET–CT resulted in changes of CT-based staging in 25% patients (up-staged in 3 and down-staged in 4. GTV delineated on PET vs CT scan was GTV-PET (primary of 20.15 cm3 vs GTV-CT (primary of 18.75 cm3, p = 0.803; and GTV-PET (nodes of 28.45 cm3 vs GTV-CT (nodes of 21.56 cm3, p = 0.589. The mismatch between two target volumes was statistically insignificant (p = 0.635 for GTV primary, p = 0.187 for nodes. The mean GTV-PET outside CT for primary was 5.83 cm3, and for node was 8.47 cm3. Median follow-up was 12 months. One-year loco-regional control was 92%. The target delineation of GTV can be improved with functional imaging [18F]-FDG-PET/CT.

  5. 鼻咽癌调强放疗对甲状腺血流动力学改变及功能影响的研究%A study of the effects of intensity-modulated conformal radiotherapy for nasophryngeal carcinoma on thyroid haemodynamics and functions

    Institute of Scientific and Technical Information of China (English)

    戚正君; 吴伟莉; 金风; 陆方阳; 龙金华; 李媛媛

    2016-01-01

    inevitably involved. As a result, thyroid damage occurs. This study aimed to explore the effects of intensity modulated radiation therapy (IMRT) on dynamics of thyroid blood flow in patients with NPC.Methods:A total number of 68 patients with NPC were enrolled in the study who received primary treatment of radical radiation and chemotherapy from Jul. 2012 to Oct. 2013. And the TMN stage was fromⅡ toⅣc according to UICC 2010. The treatment method consisted of 2 cycles of TPF induction treatment, concurrent radiation therapy (IMRT) with 2 cycles of DDP and 2 cycles of adjuvant therapy sequentially. Before radiotherapy, at the end of radiotherapy, 3 and 6 months after radiotherapy, serum free triiodothyronine (FT3), free thyroxin (FT4) and thyroid-stimulating hormone (TSH) concentrations of all cases were detected by electrochemiluminescence. The highest systolic velocity, mean velocity, minimum diastolic velocity, resistance index, and the value of all thyroid diameter lines were measured by type-B ultrasound.Results:All the patients were followed up for 6 months. Hypothyroidism: the incidence of immediate clinical hypothyroidism after radiotherapy was 5.9%; 3 months later, the incidence was 13.2%; and 6 months later, the incidence was 26.5%. The difference in volume change between before radiotherapy and at the end of radiotherapy had no statistical signiifcance (P>0.05). The difference in volume change between 3 and 6 months after radiotherapy had statistical signiifcance (P0.05).Conclusion:The incidence of hypothyroidism may increase with time after radiotherapy. The volume may decrease with the increased dose of radiotherapy and the follow-up time. The patients with NPC after radiotherapy should be tested for thyroid lesions routinely. The thyroid dose-volume parameter V40 may be a predictor for acute radioactive thyroid lesions. The study did not reveal temporarily that hypothyroidism was associated with thyroid ultrasound blood lfow velocity.

  6. Comparison of acute and subacute genitourinary and gastrointestinal adverse events of radiotherapy for prostate cancer using intensity-modulated radiation therapy, three-dimensional conformal radiation therapy, permanent implant brachytherapy and high-dose-rate brachytherapy

    NARCIS (Netherlands)

    Morimoto, Masahiro; Yoshioka, Yasuo; Konishi, Koji; Isohashi, Fumiaki; Takahashi, Yutaka; Ogata, Toshiyuki; Koizumi, Masahiko; Teshima, Teruki; Bijl, Henk P; van der Schaaf, Arjen; Langendijk, Johannes A; Ogawa, Kazuhiko

    2014-01-01

    AIMS AND BACKGROUND: To examine acute and subacute urinary and rectal toxicity in patients with localized prostate cancer monotherapeutically treated with the following four radiotherapeutic techniques: intensity-modulated radiation therapy, three-dimensional conformal radiation therapy,

  7. 食管癌放疗后复发再程调强放疗的临床观察%Clinical efficacy of intensity modulated radiation therapy for loco-regionally recurrent e-sophageal cancer after initial radiotherapy

    Institute of Scientific and Technical Information of China (English)

    彭雷; 卢鑫; 朱兆峰

    2014-01-01

    目的:探讨调强放疗(intensity modulater radiation therapy,IMRT)在食管癌首程放疗后局部复发患者中的应用及临床观察。方法:37例首程放疗后局部复发的食管鳞癌患者,采用调强放疗技术进行二程放疗,处方剂量为(50-60)Gy/[2Gy·(25-30)f]。结果:37例患者中完全缓解(complete response,CR)7例,部分缓解(partial response,PR)20例,有效率(response rate,RR)为73.0%(27/37)。本组患者1、2、3年生存率分别为59.5%、32.4%、21.1%。放射性食管炎、骨髓抑制、胃肠道反应的发生率较高。全部病例随访资料完整。截止2012年12月,25例患者已经死亡,其中死于局部复发11例、远处转移8例、食管气管瘘2例、大出血2例、其他疾病1例、自杀1例。结论:调强放疗对于食管癌首程放疗后局部复发患者是一种较好的有效的治疗方法,能取得较好的局部控制率。%Objective:To evaluate the applications and clinical effect of intensity modulated radiation therapy (IMRT)for loco-regionally recurrent esophageal cancer after initial radiotherapy.Methods:All 37 patients with loco-regionally recurrent esophageal cancer after initial radiotherapy were treated with IMRT,with a total dose of (50-60)Gy/[2Gy·(25 -30)f].Results:Of 37 patients,7 patients achieved completed remission,20 patients achieved partial remission,the effective rate was 73.0%(27/37).The overall 1 -,2 -,3 -year survival rates were 59.5%, 32.4%,21.1%.In the radiation therapy,the incidence rates of radiation esophagitis and arrest of bone marrow were high.In followed up,until December 2012,25 patients died,1 1 from local recurrence,8 from distant metastases,2 from esophageal leak,2 from haemorrhage,1 from other disease,1 from suicide.Conclusion:To patients with loco-regionally recurrent esophageal cancer after initial radiotherapy,IMRT is an alternative effective method,can improve the local

  8. Dosimetric comparison for volumetric modulated arc therapy and intensity-modulated radiotherapy on the left-sided chest wall and internal mammary nodes irradiation in treating post-mastectomy breast cancer

    Science.gov (United States)

    Zhang, Qian; Yu, Xiao Li; Hu, Wei Gang; Chen, Jia Yi; Wang, Jia Zhou; Ye, Jin Song; Guo, Xiao Mao

    2015-01-01

    Background The aim of the study was to evaluate the dosimetric benefit of applying volumetric modulated arc therapy (VMAT) on the post-mastectomy left-sided breast cancer patients, with the involvement of internal mammary nodes (IMN). Patients and methods The prescription dose was 50 Gy delivered in 25 fractions, and the clinical target volume included the left chest wall (CW) and IMN. VMAT plans were created and compared with intensity-modulated radiotherapy (IMRT) plans on Pinnacle treatment planning system. Comparative endpoints were dose homogeneity within planning target volume (PTV), target dose coverage, doses to the critical structures including heart, lungs and the contralateral breast, number of monitor units and treatment delivery time. Results VMAT and IMRT plans showed similar PTV dose homogeneity, but, VMAT provided a better dose coverage for IMN than IMRT (p = 0.017). The mean dose (Gy), V30 (%) and V10 (%) for the heart were 13.5 ± 5.0 Gy, 9.9% ± 5.9% and 50.2% ± 29.0% by VMAT, and 14.0 ± 5.4 Gy, 10.6% ± 5.8% and 55.7% ± 29.6% by IMRT, respectively. The left lung mean dose (Gy), V20 (%), V10 (%) and the right lung V5 (%) were significantly reduced from 14.1 ± 2.3 Gy, 24.2% ± 5.9%, 42.4% ± 11.9% and 41.2% ± 12.3% with IMRT to 12.8 ± 1.9 Gy, 21.0% ± 3.8%, 37.1% ± 8.4% and 32.1% ± 18.2% with VMAT, respectively. The mean dose to the contralateral breast was 1.7 ± 1.2 Gy with VMAT and 2.3 ± 1.6 Gy with IMRT. Finally, VMAT reduced the number of monitor units by 24% and the treatment time by 53%, as compared to IMRT. Conclusions Compared to 5-be am step-and-shot IMRT, VMAT achieves similar or superior target coverage and a better normal tissue sparing, with fewer monitor units and shorter delivery time. PMID:25810708

  9. Induction Chemotherapy Improved Long-term Outcomes of Patients with Locoregionally Advanced Nasopharyngeal Carcinoma: A Propensity Matched Analysis of 5-year Survival Outcomes in the Era of Intensity-modulated Radiotherapy

    Science.gov (United States)

    Peng, Hao; Chen, Lei; Zhang, Jian; Li, Wen-Fei; Mao, Yan-Ping; Zhang, Yuan; Liu, Li-Zhi; Tian, Li; Lin, Ai-Hua; Sun, Ying; Ma, Jun

    2017-01-01

    Background: The aim of this study is to evaluate the long-term therapeutic gain of induction chemotherapy (IC) in locoregionally advanced nasopharyngeal carcinoma (NPC) in the era of intensity-modulated radiotherapy (IMRT). Methods: Data on 957 patients with stage T1-2N2-3 or T3-4N1-3 NPC treated with IMRT were retrospectively reviewed. Propensity score matching (PSM) method was adopted to balance influence of various covariates. Patient survival between IC and non-IC groups were compared. Results: For the 318 pairs selected from the original 957 patients by PSM, the median follow-up duration was 57.13 months (range, 1.27-78.1 months). The 5-year overall survival (OS), distant metastasis-free survival (DMFS), disease-free survival (DFS) and locoregional relapse-free survival (LRRFS) rates for IC group vs. non-IC group were 87.2% vs. 80.8% (P = 0.023), 88.1% vs. 83.2% (P = 0.071), 80.7% vs. 71.4% (P = 0.011) and 92.1% vs. 86.7% (P = 0.081), respectively. Multivariate analysis identify IC as an independent prognostic factor for OS (HR, 0.595; 95% CI, 0.397-0.891; P = 0.012) and DFS (HR, 0.627; 95% CI, 0.451-0.872; P = 0.006). After excluding the patients not receiving concurrent chemotherapy, IC was found to be an independent prognostic factor for OS (HR, 0.566; 95% CI, 0.368-0.872; P = 0.01), DMFS (HR, 0.580; 95% CI, 0.367-0.916; P = 0.02) and DFS (HR, 0.633; 95% CI, 0.444-0.903; P = 0.012). Conclusions: IC is an effective treatment modality for patients with stage T1-2N2-3 and T3-4N1-3 NPC, and the incorporation of IC with standard CCRT could achieve the best therapeutic gain. PMID:28261337

  10. Radioterapia de intensidad modulada en el tratamiento de tumores en pediatría, primeros casos en Cuba: first cases in Cuba Intensity Modulated Radiotherapy in treatment of tumors in children

    Directory of Open Access Journals (Sweden)

    José Alert Silva

    2011-06-01

    Full Text Available INTRODUCCIÓN. La radioterapia de intensidad modulada (IMRT constituye una técnica de alta precisión basada en la definición volumétrica tridimensional de la anatomía del tumor y de los órganos críticos o en riesgo. Con el objetivo de asegurar la posibilidad de aplicar la IMRT en Cuba, en casos seleccionados de tumores en niños y adolescentes, se instrumentó un proyecto de investigación cuyos resultados se documentan en este informe. MÉTODOS. Se realizaron las primeras irradiaciones con IMRT en niños y adolescentes cubanos, con edades entre 6 y 18 años. La técnica empleada es la basada en aperturas geométricas y optimización inversa. Las irradiaciones fueron realizadas con un acelerador lineal con fotones de 6 MV, con colimador multiláminas. Las dosis de radiaciones administradas variaron según el tipo de tumor, y de acuerdo con las normas de radioterapia y la presencia de órganos críticos. Todos los pacientes fueron evaluados semanalmente, con controles radiológicos mediante placas portales electrónicas. RESULTADOS. Los pacientes irradiados (5 tenían los tumores siguientes: linfoma no-Hodgking del seno maxilar (1, glioma del tallo cerebral (1, linfoma no-Hodgking abdominal (1, condrosarcoma mesenquimatoso parameníngeo (1 y hemangiopericitoma parameníngeo (1. Las dosis de irradiación recibidas variaron entre 24 y 62 Gy. Fueron empleados entre 5 y 8 campos, con variaciones entre 10 y 20 segmentos. CONCLUSIONES. Se realizaron en Cuba las primeras irradiaciones con IMRT en niños y adolescentes, y se debe continuar extendiendo su empleo en aquellos casos donde su utilidad sea mayor.INTRODUCTION. The intensity modulated radiotherapy (IMRT is a high performance technique based on the three-dimensional volumetric definition of tumor anatomy and of critical organs or at risk. To assure the possibility to apply the IMRT in Cuba in selected cases of tumors in children and adolescents, authors designed a research project whose

  11. Dosimetric comparison between volumetric modulated arc radiotherapy and intensity-modulated radiotherapy for locally recurrent naso-pharyngeal carcinoma%局部复发鼻咽癌旋转容积调强与固定野动态调强放疗技术的剂量学比较

    Institute of Scientific and Technical Information of China (English)

    陆佳扬; 张基永; 张武哲; 彭逊; 李梅; 吴丽丽; 谢文佳; 谢良喜

    2016-01-01

    目的:比较旋转容积调强放疗( VMAT)技术与固定野动态调强放疗( IMRT)技术在复发鼻咽癌应用中的剂量学差异。方法选取11例局部复发鼻咽癌患者,分别设计双弧VMAT与七野IMRT两组计划,比较两组计划的靶区( PTV)剂量参数、适形指数( CI)和均匀指数( HI),以及危及器官(OAR)剂量参数、机器监测跳数(MU)、投照时间。结果 VMAT的 PTV D98%略低于 IMRT(P<0.05),CI高于 IMRT(P<0.05),HI与IMRT无显著差异(P>0.05)。 VMAT 中双侧颞叶的 Dmean 与周围正常组织的 Dmean 均比 IMRT 低(P<0.05),脑干的 Dmean 略高于 IMRT(P<0.05),在其他危及器官两者无显著差异(P>0.05)。 VMAT的MV(672±112)明显少于IMRT(917±206),幅度约(25±13)%(P<0.05),VMAT投照时间〔(2.3±0.1)min〕比IMRT〔(5.1±0.4)min〕减少(54±3)%。结论局部复发鼻咽癌VMAT计划可以达到或略优于IMRT计划的靶区剂量分布,能更好地保护双侧颞叶,有效减少MU和投照时间。%Objective To compare volumetric modulated arc radiotherapy( VMAT) technique with fixed-gantry intensity-modulated ra-diotherapy( IMRT) technique based on dynamic multi-leaf collimator for locally recurrent nasopharyngeal carcinoma.Methods CT data from e-leven nasopharyngeal-carcinoma patients were included.Dual-arc VMAT and 7-field IMRT plans were created for each case and were compared in terms of conformity index(CI),homogeneity index(HI)of the planning target volume(PTV),organ-at-risk(OAR)sparing,monitor unit(MU) and delivery time.Results The D98%(near-minimal dose)of PTV in the VMAT plans was slightly lower than that of the IMRT plans(P0.05).Compared with the IMRT plans,the VMAT plans demonstrated lower mean doses of the bilateral temporal lobes and the whole surrounding normal tissue(P0.05).The MU of VMAT plans(672±112)was significantly less than that of the IMRT plans

  12. 胰腺癌不同调强方式的剂量学比较%Dosimetric Comparison of Different Pattern of Intensity-modulated Radiotherapy for Pancreatic Carcinoma

    Institute of Scientific and Technical Information of China (English)

    王伟平; 杨波; 庞廷田; 刘楠; 胡克; 邱杰; 张福泉

    2014-01-01

    目的:比较胰腺癌术后患者固定野调强放疗( fixed-field intensity-modulated radiotherapy, FF-IMRT)与容积调强放疗(volumetricmodulatedarctherapy,VMAT)的剂量学差异,为临床选择合适的照射技术提供参考。方法2011年6月至12月在北京协和医院行放疗的10例胰腺癌术后患者,分别根据其同一CT模拟定位图像设计FF-IMRT计划和VMAT计划,处方剂量50 Gy/25次。分析剂量体积直方图曲线,评估靶区、危及器官和正常组织的剂量分布,并比较二者机器跳数(monitor units, MU)和治疗时间的差别。结果 FF-IMRT计划和 VMAT 计划的靶区剂量分布差异无统计学意义(P>0.05)。与FF-IMRT计划相比, VMAT计划中肝脏、胃、小肠、全身的V5明显升高(P均<0.05),而肝脏的V10和V20,胃的V10,小肠的V10、 V20、 V50,左肾的V20,右肾的V20、 V30、 Dmean、 Dmax,以及全身的V10、 V20有不同程度下降(P均<0.05),脊髓的 Dmax升高1.85 Gy (P=0.04)。 FF-IMRT计划与 VMAT计划的 MU 分别为619.60±117.18和492.70±51.56(t =3.18, P =0.01)。 VMAT 计划的 MU 较 FF-IMRT 计划减少了20.48%。结论胰腺癌患者选择VMAT计划,可以在不降低计划水平上的剂量分布的前提下,大大减少MU,缩短治疗时间。%Objective To analyze the dosimetric differences between fixed-field intensity-modulated ra-diotherapy ( FF-IMRT) and volumetric modulated arc therapy ( VMAT) in treating pancreatic carcinoma , aiming to facilitate the clinical decision upon appropriate radiation technique .Methods From June to December 2011 , 10 postoperative patients of pancreatic carcinoma who received radiotherapy in Peking Union Medical College Hos -pital were selected for this comparison .FF-IMRT and VMAT plans were developed based on the same CT simula-tion image for each patient .The prescription dose was 50 Gy in 25 fractions.The doses distributions in planning

  13. Intensity modulated radiation therapy: Analysis of patient specific quality control results, experience of Rene-Gauducheau Centre; Radiotherapie conformationnelle avec modulation d'intensite: analyse des resultats des controles precliniques, experience du centre Rene-Gauducheau

    Energy Technology Data Exchange (ETDEWEB)

    Chiavassa, S.; Brunet, G.; Gaudaire, S.; Munos-Llagostera, C.; Delpon, G.; Lisbona, A. [Service de physique medicale, centre Rene-Gauducheau, CLCC Nantes Atlantique, site hospitalier Nord, boulevard Jacques-Monod, 44805 Nantes Saint-Herblain cedex (France)

    2011-07-15

    Purpose. - Systematic verifications of patient's specific intensity-modulated radiation treatments are usually performed with absolute and relative measurements. The results constitute a database which allows the identification of potential systematic errors. Material and methods. - We analyzed 1270 beams distributed in 232 treatment plans. Step-and-shoot intensity-modulated radiation treatments were performed with a Clinac (6 and 23 MV) and sliding window intensity-modulated radiation treatments with a Novalis (6 MV). Results. - The distributions obtained do not show systematic error and all the control meet specified tolerances. Conclusion. - These results allow us to reduce controls specific patients for treatments performed under identical conditions (location, optimization and segmentation parameters of treatment planning system, etc.). (authors)

  14. Prospective phase Ⅱ trial of hypofractionated intensity-modulated radiotherapy for localized prostate cancer%局限期前列腺癌大分割调强放疗临床Ⅱ期研究

    Institute of Scientific and Technical Information of China (English)

    刘跃平; 余子豪; 戴建荣; 李晔雄; 王维虎; 房辉; 金晶; 王淑莲; 宋永文; 任骅; 刘新帆

    2012-01-01

    目的 观察前列腺癌2.7Gy25次大分割调强适形放疗的疗效和不良反应.方法 2009-2011年52例局限于盆腔的前列腺癌接受前列腺加或不加精囊腺2.7 Gy 25次(总量67.5 Gy)调强放疗,其中20例仅为前列腺加或不加精囊腺照射,32例为前列腺加精囊腺和盆腔淋巴引流区预防照射,盆腔剂量50 Gy分25次照射.35例采用了图像引导放疗,48例同时接受内分泌治疗.结果 中位随诊13个月,平均前列腺特异抗原由疗前(40.3±36.6)ng/ml降至随诊时的(0.5±1.7)ng/ml.2例治疗失败,其中生化失败1例、盆腔淋巴结复发1例.放疗毒性反应:消化道急性反应2级为25%、3级为4%,泌尿道急性反应2级为15%、3级为2%.消化道晚期损伤2级为17%、3级为0%,泌尿道晚期损伤2级为8%、3级为2%.因大部份病例放疗同时接受了内分泌治疗故无法评价性功能影响.结论 局限期前列腺癌大分割调强放疗近期疗效较满意,严重不良反应少见,长期疗效和不良反应有待更长时间随诊评价.%Objective To prospectively evaluate the efficacy and toxicity of hypofractionated intensity-modulated radiotherapy (IMRT) for prostate cancer.Methods Fifty-two consecutive patients with localized prostate cancer were enrolled in this study between Feb.2009 and Mar.2011.All patients received hypofractionated IMRT (2.7 Gy/fx,25 fractions,total 67.5 Gy) to the prostate and seminal vesicles.32 high risk patients also received prophylactic irradiation to the pelvic lymph nodes concurrently (2 Gy/fx,25 fractions).Imaging-guided radiotherapy was employed in 35 patients.Androgen deprivation therapy was adopted in 48 of 52 patients.Results After a median follow-up of 13 months,the mean prostate specific antigen (PSA) was reduced from (40.3 ± 36.6) ng/ml before treatment to (0.5 ± 1.7)ng/ml at the last follow-up.By the time of last follow-up,2 patients (4%) failed.One had PSA failure and the other had both PSA failure and

  15. 前列腺癌大分割调强放疗副反应初步分析%Toxicity of hypofractionated intensity-modulated radiotherapy in patients with prostate cancer

    Institute of Scientific and Technical Information of China (English)

    房辉; 刘清峰; 戴建荣; 余子豪; 李晔雄; 刘跃平; 王维虎; 金晶; 王淑莲; 宋永文; 刘新帆; 亓姝楠

    2009-01-01

    目的 分析前列腺癌大分割照射患者的早期和晚期副反应,初步探讨副反应的影响因素.方法 2006-2008年间37例前列腺痛患者接受大分割调强放疗(IMRT).13例临床靶体积(CTV)包括前列腺±精囊或术后瘤床,24例包括前列腺、精囊(或术后瘤床)和盆腔淋巴引流区.分次照射剂量为2.3~2.8 Gy(2.7 Gy占26例).95%PTV处方剂量前列腺精囊为62.5~75.0 Gy,盆腔为50.0 Gy.结果 全组中位随访时间为14个月.早期胃肠反应发生率0级38%,1级2,4%,2级35%,3级3%;直肠V50>27%与V55>20%的≥1级早期直肠反应发生率不同(P10%的≥1级泌尿系统反应发生率也不同(X2=6.02,P=0.038).晚期直肠反应发生率0级70%,1级24%,2级5%,无3、4级反应;直肠V6510%的≥1级晚期胃肠反应发生率不同(X2=5.58,P=0.020).晚期泌尿系统反应发生率0级38%,1级49%,2级11%,3级3%,无4级反应;膀胱平均剂量>40Gy、V40>32%与V50>29%的≥2级晚期泌尿系统反应发生率均不同.结论 前列腺癌大分割IMRT初步研究结果 显示急件和晚期副反应均在可接受范围内.%Objective To analyze the acute and late toxicities in patients with prostate cancer trea-ted with hypofractionated intensity-modulated radiotherapy (IMRT). Methods Between June 2006 and June 2008, 37 patients with prostate cancer were treated with hypofractionated IMRT. The clinical target vol-ume (CTV) was the prostate, seminal vesicles and pelvic lymph nodes in 24 patients, the prostate and semi-hal vesicles in 12, and only the tumor bed in 1. The dose per fraction was 2.3 - 2.8 Gy, with 2.7 Gy in 26 patients. The minimal dose was 62.5-75.0 Gy to the prostate and seminal vesicles, and 50 Gy to the pelvic lymph nodes. Results The median follow-up was 14 months. None of the patients experienced grade 4 a-cute gastro-intestinal (GI) toxicity. Grade 1, 2 and 3 acute GI toxicity occurred in 24.3%, 35.1% and 2.7% of the patients, respectively. The rectal V50>27% and V55>20% were highly

  16. Nursing of Recurrent and Advanced Rectal Cancer Patients Receiving Concurrent XELOX Chemotherapy and Intensity Modulated Conformal Radiotherapy%XELOX方案同期化疗联合调强适形放疗治疗复发和局部晚期直肠癌的护理

    Institute of Scientific and Technical Information of China (English)

    陈世梅; 李莉

    2011-01-01

    Objective: To discuss the nursing methods of recurrent and locally advanced rectal cancer patients receiving concurrent XELOX regimen( Xeloda plus LOHP ) chemotherapy and intensity modulated conformal radiotherapy.Methods: Clinical records of 32 cases of recurrent and locally advanced rectal cancer accepting concurrent XELOX regimen chemotherapy and intensity modulated conformal radiotherapy were analyzed.Nursing procedures including pre-therapy psychological nursing was used before therapy,and suitable nursing measures were used during and after treatment.Results: The overall effective rate was 78.1% with 3 cases got CR and 22 PR.The main side-effects included nyelosuppression, neurotoxicity, hand-foot syndrome, nausea and vomiting, diarrhea,radiation proctitis, and cystitis.Conclusion: The concurrent XELOX regimen chemotherapy and intensity modulated conformal radiotherapy is proved effective in the treatment of recurrent and locally advanced rectal cancer.In order to accelerate the recovery of patients and improve their life qulities after chemoradiotherapy, appropriate nursing on the nutrition, skin, mouth, ostomy and psychological status of patients should be carried out to alleviate the side-effects.%目的:探讨卡培他滨(Xeloda,希罗达)联合奥沙利铂(LOHP)(XELOX方案)同期化疗联合调强适形放疗治疗复发和局部晚期直肠癌的临床护理.方法:对32例复发和局部晚期直肠癌患者XELOX方案同期化疗联合调强适形放疗的临床资料进行回顾性分析,治疗前采取心理护理,治疗期间及治疗后采取相应的护理措施.结果:本组32例患者中CR 3例,PR 22例,总有效率为78.1%.主要不良反应为骨髓抑制、神经系统毒性、手足综合征、恶心呕吐、腹泻、放射性直肠炎及膀胱炎等,但均无Ⅲ度-Ⅳ度毒副反应发生.结论:XELOX方案同期调强适形放疗治疗复发和局部晚期直肠癌配合有效的护理措施,能有效减轻放化疗的副反应,有

  17. Long-term outcomes of a phase II randomized controlled trial comparing intensity-modulated radiotherapy with or without weekly cisplatin for the treatment of locally recurrent nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ying Guan; Shuai Liu; HanYu Wang; Ying Guo; WeiWei Xiao; ChunYan Chen; Chong Zhao; TaiXiang Lu; Fei Han

    2016-01-01

    Background: Salvage treatment for locally recurrent nasopharyngeal carcinoma (NPC) is complicated and relatively limited. Radiotherapy, combined with effective concomitant chemotherapy, may improve clinical treatment out‑comes. We conducted a phase II randomized controlled trial to evaluate the efcacy of intensity‑modulated radio‑therapy with concomitant weekly cisplatin on locally recurrent NPC. Methods: Between April 2002 and January 2008, 69 patients diagnosed with non‑metastatic locally recurrent NPC were randomly assigned to either concomitant chemoradiotherapy group (n = 34) or radiotherapy alone group(n= 35). All patients received intensity‑modulated radiotherapy. The radiotherapy dose for both groups was 60 Gy in 27 fractions for 37 days (range 23–53 days). The concomitant chemotherapy schedule was cisplatin 30 mg/m2 by intravenous infusion weekly during radiotherapy. Results: The median follow‑up period of all patients was 35 months (range 2–112 months). Between concomitant chemoradiotherapy and radiotherapy groups, there was only significant difference in the 3‑year and 5‑year overall survival (OS) rates (68.7% vs. 42.2%, P = 0.016 and 41.8% vs. 27.5%, P = 0.049, respectively). Subgroup analysis showedthat concomitant chemoradiotherapy significantly improved the 5‑year OS rate especially for patients in stage rT3–4 (33.0% vs. 13.2%, P = 0.009), stages III–IV (34.3% vs. 13.2%, P = 0.006), recurrence interval >30 months (49.0% vs. 20.6%,P= 0.017), and tumor volume >26 cm3 (37.6% vs. 0%, P = 0.006). Conclusion: Compared with radiotherapy alone, concomitant chemoradiotherapy can improve OS of the patients with locally recurrent NPC, especially those with advanced T category (rT3–4) and stage (III–IV) diseases, recurrence intervals >30 months, and tumor volume >26 cm3.

  18. Intensity-Modulated Radiation Therapy for Primary Brain Tumors

    Institute of Scientific and Technical Information of China (English)

    Zhong-min Wang

    2004-01-01

    Radiation therapy has been used to treat primary brain tumors as standard primary and/or adjunctive therapies for decades. It is difficult for conventional radiotherapy to deliver a lethal dose of radiation to the tumors while sparing surrounding normal brain due to complicated structures and multifunction in human brain. With the understanding of radiation physics and computer technology, a number of novel and more precise radiotherapies have been developed in recent years. Intensity modulated radiotherapy (IMRT) is one of these strategies. The use of IMRT in the treatment of primary brain tumors is being increasing nowadays. It shows great promise for some of primary brain tumors and also presents some problems, This review highlights current IMRT in the treatment of mainly primary brain tumors.

  19. Study on the Optimization Algorithms for Intensity-Modulated Radiation Therapy

    Institute of Scientific and Technical Information of China (English)

    LI Yong-jie

    2005-01-01

    @@ Radiotherapy, together with the surgery and chemotherapy, are the three main means for tumor treatment. It is a historic advancement for tumor treatment that the classical three-dimensional (3D)conformal radiotherapy (3DCRT) evolved into the intensity-modulated radiotherapy (IMRT). Whereas,the advantages of IMRT have not yet been fully utilized, because of the complicated clinical conditions.The IMRT planning, one of the key issues of IMRT application, still has many problems open to be further studied.

  20. 宫颈癌术后盆腔容积调强弧形治疗与固定野调强放疗计划的剂量学研究%Dosimetric study of volumetric intensity-modulated arc therapy and fixed field intensity-modulated radiotherapy for cervix cancer

    Institute of Scientific and Technical Information of China (English)

    杨波; 庞廷田; 孙显松; 胡克; 邱杰; 张福泉

    2012-01-01

    Objective To compare the dosimetry characteristics of volumetric intensity-modulated arc therapy (VIMAT) and fixed field intensity-modulated radiation therapy (FF-IMRT) for cervix cancer.Methods CT images of 13 patients with cervix uteri cancer were transferred into Eclipse planning system.FF-IMRT and VIMAT plans were optimized on an Eclipse treatment planning system using beam data generated for Varian trilogy linear accelerator.Planning target volume (PTV) and organs at risk were evaluated with dose-volume histogram.To appraise the difference between the techniques,the paired t-test was applied.Results Compared with the FF-IMRT plans,PTV95% coverage of VIMAT plan group increased (t =9.84,P =0.000),PTV110% became lower (t =-3.72,P =0.003),Dmax decreased (t =-3.51,P=0.005),and CI became worser (t=5.39,P=0.000).PTV105%,Dmean,and HI had no difference (t =-0.02,-0.60,1.13,P =0.842,0.560,0.283).V30 of the bladder was reduced by about 10% (t =-4.99,P =0.000),and Dmean and Dmax were 1.4 Gy and 1.5 Gy lower respectively (t =-3.65,-18.03,P =0.004,0.000) ;V40 of the rectum was reduced by about 10% (t =-2.99,P =0.012),and Dmean and Dmax were reduced by 0.6 Gy,0.8 Gy respectively (t =-2.98,-4.05,P =0.013,0.002) ;V30,V40 and V50 of the small intestine were reduced by 16%,10% and 11% (t =-10.85,-4.74,-8.66,P =0.000,0.001,0.000),and Dmax was reduced by 0.8 Gy (t =-9.45,P =0.000) ; V30,V40 and V50 of the bone marrow were reduced by 26%,19% and 16% (t =-22.10,-10.19,-4.04,P =0.000,0.000,0.002),and Dmean reduced by 1.9 Gy (t =-16.21,P =0.000) ; D5 of the left and right femoral heads were reduced by 1.6 Gy and 2.7 Gy (t =-2.89,-6.22,P =0.015,0.000).Dmax of the caudate equine was reduced by 1.5 Gy (t=-4.80,P=0.001).V20,V30,V40 and V50 of the body were reduced by 18%,18%,4% and3%(t=-7.52,-11.75,-6.26,-6.94,P=0.000,0.000,0.000,0.000).Dmean and Dmax of the body decreased by 1.0 Gy and 0.4 Gy (t=-3.72,-3.51,P=0.000,0.005).Average machine unit (MU) decreased

  1. Definitive salvage for vaginal recurrence of endometrial cancer: the impact of modern intensity-modulated-radiotherapy with image-based HDR brachytherapy and the interplay of the PORTEC 1 risk stratification.

    Science.gov (United States)

    Vargo, John A; Kim, Hayeon; Houser, Christopher J; Berhane, Hebist; Sukumvanich, Paniti; Olawaiye, Alexander B; Kelley, Joseph L; Edwards, Robert P; Comerci, John T; Huang, Marilyn; Courtney-Brooks, Madeleine; Beriwal, Sushil

    2014-10-01

    Data for salvage radiotherapy for recurrent endometrial cancer are limited especially in the era of modern radiotherapy including IMRT and 3-dimensional image-based HDR brachytherapy. Theoretically, modern radiotherapy reduces the dose to critical organs-at-risk and maximizes dose to the target volume, possibly decreasing morbidity and increasing tumor control. Forty-one patients completing definitive salvage radiotherapy for vaginal recurrence of endometrial cancer from June 2004 to December 2013 were retrospectively reviewed. HDR Brachytherapy was completed using image-based planning with contouring/optimization with each fraction to a median dose of 23.75 Gy in 5 fractions. HDR brachytherapy was preceded by external beam radiotherapy predominately using an IMRT technique (90%) to a median dose of 45 Gy in 25 fractions. Toxicity was reported according to CTCAEv4. At a median follow-up of 18 months (range: 3-78), the clinical complete response rate was 95%. The 3-year local control, distant control, recurrence free survival, and overall survival were 95%, 61%, 68%, and 67%. Significant predictors of both distant failure and overall survival were primary prognostic factors of depth of myometrial invasion, FIGO stage, and FIGO grade. There was no grade 3+ acute toxicity; the 3-year rate of grade 3+ late toxicity was 8%. Salvage IMRT plus 3-dimensional image-based HDR brachytherapy shows excellent tumor control and minimal morbidity for vaginal recurrence of endometrial cancer. Anticipated salvage rates must be taken in the context of primary risk factors including depth of myometrial invasion, FIGO stage, and FIGO grade. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. 宫颈癌术后三维适形放疗和共面等分设野调强放疗计划的对比分析%Dosimetric study of postoperative 3-dimensional conformal radiotherapy and coplanar decile intensity-modulated radiotherapy for cervical cancer

    Institute of Scientific and Technical Information of China (English)

    蒋军; 张利文; 廖珊; 黄荣

    2012-01-01

    目的 探讨宫颈癌术后三维适形放射治疗(3D-CRT)和共面等分设野调强放射治疗(IMRT)计划靶区及其周围危及器官受照剂量的差异.方法 随机选择10例宫颈癌术后患者,进行CT扫描、靶区和危及器官的勾画,处方剂量50 Gy.分别进行3D-CRT和共面等分设野IMRT计划设计,计算靶区剂量均匀度指数(HI)、适形度指数(CI)、最大受照剂量、最小受照剂量、平均受照剂量和危及器官照射体积等并对结果进行比较分析.结果 5F-IMRT、7F-IMRT和9F-IMRT在靶区适形度方面明显优于3D-CRT;在危及器官(膀胱V30 、V40 、V50,小肠V50和直肠V30、V40、V50)保护方面,5F-IMRT、7F-IMRT和9F-IMRT明显优于3D-CRT,P<0.05.而各IMRT计划之间差异无统计学意义,P>0.05.结论 宫颈癌术后辅助放疗共面等分IMRT计划无论在靶区适形度还是正常组织保护方面均优于3D-CRT,同时也证实7野或9野IMRT未必较5野获益更多.5野与7、9野的IMRT相比、在治疗时间及费用方面有独特的优势,值得在临床上推广.%Objective To compare the difference of the dose distribution in clinical target volume and organ at risk (OAR) between coplanar decile field intensity-modulated radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy (3D-CRT) for postoperative radiotherapy of cervical cancer. Methods Ten postoperative patients with cervical cancer were selected randomly to undergo CT scan and planning target volume (PTV) and OAR contouring. 3D-CRT and coplanar decile IMRT planning was performed for each patient with a prescribed dose of 50 Gy. The homogeneity index (HI), conformity index (CI), maximum dose, minimum dose, mean dose of PTV, and irradiated volume of OARs were calculated and the results were compared. Results 5-field IMRT, 7-field IMRT and 9-field IMRT plans had a significant better conformity index (CI) of PTV compared with 3D-CRT (P0.05). Conclusion Coplanar decile IMRT plans is superior

  3. 中上段食管癌3D-CRT与IMRT肺损伤剂量学的对比研究%Dosimetric Comparison of Intensity-modulated Radiotherapy Versus 3D Conformal Radiotherapy in Treatment of Cancer of Upper/Mid Esophagus

    Institute of Scientific and Technical Information of China (English)

    张莉; 罗辉

    2011-01-01

    Objective To compared 3D-conformal radiotherapy (3D-CRT)-induced and intensity-modulated radiotherapy (IMRT)-induced pulmonary injury by using 3D treatment planning system,and to explore the optimum treatment strategy for upper/mid esophageal carcinoma.Methods Eight patients with upper/mid esophageal carcinoma were selected in this study. Four different radiotherapy plans were developed for each patient,including 5-field 3D-CRT(CRT5),7-field 3D-CRT(CRT7), 5-field IMRT (IMRT5) and 7-field IMRT (IMRT7). The planning target volume (PTV) received at least 95% of the prescription dose. The mean lung dose (MLD),V5,V10,V20 and V30 were evaluated using dose volume histogram(DVH). All statistics were analyzed using the SPSS version 11.5 software. Results CRT5 plan reduced lung V10 compared with CRT7 (P=0. 006), but V5, V20, V30 and MLD were not different between the two plans(P>0. 008 3). There were no significant differences in lung parameters between IMRT5 and IMRT7.Compared with IMRT plans, V20, V30 and MLD were increased by 3D-CRT, while V5 was decreased by 3D-CRT(P<0. 0083). Conclusion Compared with 3D-CRT, IMRT can reduce the MLD,V20 and V30 to achieve lung sparing in treatment of upper/mid esophageal carcinoma.There were no significant differences in the protection of lung tissues between 5-field and 7-field techniques for both 3D-CRT and IMRT plans.%目的 应用三维适形放疗(3D-CRT)计划比较中上段食管鳞癌3D-CRT和调强放疗(IMRT)的放射性肺损伤情况从而探讨理想的治疗计划模式.方法 8例患者每例分别设计4个放疗计划(CRT-5 、CRT-7、IMRT-5及 IMRT-7),规定PTV至少达到95%处方剂量前提下用DVH评价每个计划的V5 、V10 、V20 、V30及肺 MLD.采用SPSS 11.5软件包进行数据统计与分析.结果 采用3D-CRT技术时,5野的V10优于7野(P=0.006);5野与7野的肺Mean、肺V5、V20、V30(P>0.0083)之间无统计学意义;采用IMRT技术时,5野与7野之间各参数的对

  4. 多叶准直器叶片速度对滑窗调强放疗剂量分布的影响研究%The Effect of Speed of Multileaf Collimator on Dose Distribution With Sliding Windows Intensity-Modulated Radiotherapy

    Institute of Scientific and Technical Information of China (English)

    徐利明; 李长虎; 李承军; 王陆州; 姚颐

    2011-01-01

    Objective: To explore the effect of speed of multileaf colhmator (MLC) on the dose distribution of the dynamic intensity-modulated radiation therapy. Methods: A group of MLC files was designed with sliding window intensity-modulated (SW-IMRT) radiation fields and was run with different dose rate and different machine unit (MU), so that the speed of the leaf were modulated at 1.0 cm/s, 2.0 cm/s, 3.0 cm/s, 4.0 cm/s, 5.0 cm/s, 6.0 cm/s, 7.0 cm/s, 8.0 cm/s, 10.0 cm/s respectively. The dose distribution with Mapcheck was measured, and the dose distribution which calculated in planning system was compared. Ten cases of nasopharyngeal carcinoma intensity-modulated plan, with 100 MU/m 200 MU/m, 300 MU/m, 400 MU/m, 500 MU/m, 600 MU/m dose rate separatively on the accelerator and dose distribution was measured with Mapcheck, and compared the dose distribution planning system in passing; simultaneously recording ten patients under the condition of different dose rate run-time accelerator log files, will log file conversion into actual operation after DMLC MLC documents, will DMLC import plan system recalculate, comparing different dose rate in patients die under the condition of the dose distribution and primitive dose distribution difference. Results: The accelerator actual blade movement speed reached (2.78±1.45) cm/s, maximum speed 4.55 cm/s; for in not more than 5.00 set speed cm/s, accelerator in operation plan file, the way by lowering the dose rate can match the vane motion speed limit, to ensure the actual illuminate the accelerator output when shooting wild flux and plan the best shot when designing Mapcheck wild flux consistent and verified in above 99%, but pass in setting cm/s faster than 5.00 when planning document, the accelerator in operation by lowering the dose rate, already can't match the way blade movement speed limits, Mapcheck verification with the speed of the passing rate rise and set down; on the actual clinical case research does not appear afore

  5. Impact of rotational set-up error in dose veracity of intensity-modulated radiotherapy%旋转摆位误差对调强放疗剂量准确性的影响

    Institute of Scientific and Technical Information of China (English)

    李志聪; 向昭雄; 游雁; 李陆军; 余海坤

    2016-01-01

    目的:分析旋转摆位误差对调强放疗剂量准确性的影响.方法:随机选取10例鼻咽癌患者的适形调强放疗(intensity-modulated radiation therapy,IMRT)计划,以患者放疗计划做模板计划(template plan,TP),然后分别旋转治疗床角度为±0.5、±1、±1.5、±2、±2.5、±3、±3.5、±5°形成不同的模拟计划(simulate plan,SP),利用OmniPro-IMRT软件对SP与TP进行比较,观察不同旋转角度在3%/3 mm标准下对gamna值的影响.结果:在旋转误差≤1.5°时,gamma值之间无统计学意义(P>0.05);旋转角度≥2°时,gamma值之间有统计学意义(P<0.05).沿相反方向旋转相同角度后,gamma值之间无统计学意义(P>0.05).结论:旋转摆位误差对靶区剂量准确性的影响与靶区长度有关;旋转误差的校正阈值为1.5°可能更为合理.

  6. Comparison of dose distribution in body gamma knife,static intensity modulated radiotherapy and volumetric modulated arc radiotherapy for small mass in lung%肺部小肿瘤γ刀、静态 IMRT 及 VMAT 放疗剂量学比较

    Institute of Scientific and Technical Information of China (English)

    唐正中; 胡宗涛; 吴爱东; 牛振洋

    2016-01-01

    Objective To explore dose distribution difference in body gamma knife,static intensity modulated radiotherapy and volu-metric modulated arc radiotherapy for small mass in lung.Methods Sixteen patients with small mass in lung were enrolled in the study,gamma knife radiotherapy plan,sIMRT plan and VMAT plan made respectively for each mass.All plans were optimized to meet the requirement of 95% target volume (PTV)covered by prescribed dose.We compared multiple parameters such as dosimetric pa-rameters of PTV,organ at risk(OAR),homogeneity index(HI)and comfomity index(CI)of three radiotherapy plans.Results Six-teen cases with three plans of PTV dose distribution and dose parameters could meet the requirements of clinical treatment,and pre-scription dose to cover 95% of the PTV,OAR dose limit could also meet the requirements.The Homogeneity index (CI)and conform-ity index (HI)of Gamma knife plan were 1.67 ±0.13 and 0.70 ±0.06,respectively,which had the worst performance among three plans(P 0.05).Conclusions Compared with sIMRT and VMAT,gamma knife radiotherapy for the treatment of small mass in lung can obviously increase the target dose and better protect OAR,but is poor in homogeneity and conformity.%目的:比较体部γ刀、静态调强(sIMRT)与容积旋转调强(VMAT)的肺部小肿瘤中放疗计划的剂量学差异。方法选择16例肺部小肿瘤患者,分别设计γ刀、sIMRT(计划2)和 VMAT 计划,使得95%靶体积(PTV)达到处方剂量要求,比较三种计划的靶区剂量、危及器官剂量、均匀指数(HI)及适形指数(CI)的差异。结果16例患者三种计划的 PTV 剂量分布及剂量参数都能达到临床治疗要求,处方剂量覆盖95%的 PTV,危及器官的剂量限值也能满足要求。γ刀计划的适形性(CI)及均匀性(HI)分别为(1.67±0.13)和(0.70±0.06),在三种计划中表现为最差(P <0.05);而 sIMRT 和 VMAT 计划的 PTV 靶区

  7. Influence of optimizing protocol choice on the integral dose value in prostate radiotherapy planning by dynamic techniques - Pilot study.

    Science.gov (United States)

    Zaleska, Anna; Bogaczyk, Krzysztof; Piotrowski, Tomasz

    2017-01-01

    The purpose of this study was to compare the values of integral dose, calculated for treatment plans of dynamic radiotherapy techniques prepared with two different optimization protocols. Delivering radiation by IMRT, VMAT and also HT techniques has an influence on the low dose deposition of large areas of the patient body. Delivery of low dose can induce injury of healthy cells. In this situation, a good solution would be to reduce the area, which receives a low dose, but with appropriate dose level for the target volume. To calculate integral dose values of plans structures, we used 90 external beam radiotherapy plans prepared for three techniques (intensity modulated radiotherapy, volumetric modulated arc therapy and helical tomotherapy). One technique includes three different geometry combinations. 45 plans were prepared with classic optimization protocol and 45 with rings optimization protocol which should reduce the low doses in the normal tissue. Differences in values of the integral dose depend on the geometry and technique of irradiation, as well as optimization protocol used in preparing treatment plans. The application of the rings optimization caused the value of normal tissue integral dose (NTID) to decrease. It is possible to limit the area of low dose irradiation and reduce NTID in dynamic techniques with the same clinical constraints for OAR and PTV volumes by using an optimization protocol other than the classic one.

  8. Mixing intensity modulated electron and photon beams: combining a steep dose fall-off at depth with sharp and depth-independent penumbras and flat beam profiles.

    Science.gov (United States)

    Korevaar, E W; Heijmen, B J; Woudstra, E; Huizenga, H; Brahme, A

    1999-09-01

    For application in radiotherapy, intensity modulated high-energy electron and photon beams were mixed to create dose distributions that feature: (a) a steep dose fall-off at larger depths, similar to pure electron beams, (b) flat beam profiles and sharp and depth-independent beam penumbras, as in photon beams, and (c) a selectable skin dose that is lower than for pure electron beams. To determine the required electron and photon beam fluence profiles, an inverse treatment planning algorithm was used. Mixed beams were realized at a MM50 racetrack microtron (Scanditronix Medical AB, Sweden), and evaluated by the dose distributions measured in a water phantom. The multileaf collimator of the MM50 was used in a static mode to shape overlapping electron beam segments, and the dynamic multileaf collimation mode was used to realize the intensity modulated photon beam profiles. Examples of mixed beams were generated at electron energies of up to 40 MeV. The intensity modulated electron beam component consists of two overlapping concentric fields with optimized field sizes, yielding broad, fairly depth-independent overall beam penumbras. The matched intensity modulated photon beam component has high fluence peaks at the field edges to sharpen this penumbra. The combination of the electron and the photon beams yields dose distributions with the characteristics (a)-(c) mentioned above.

  9. A Comparison of Volumetric Modulated Arc Therapy and Intensity-Modulated Radiotherapy for Postoperative Glioma%脑胶质瘤术后VMAT与IMRT放疗技术间比较

    Institute of Scientific and Technical Information of China (English)

    张矛; 金海国; 卜明伟; 孙宝胜; 孙术全; 苏清秀; 李玉平

    2011-01-01

    Objective: This planning study compares IMRT with VMAT for discussing the dosimetric characteristics of VMAT in the intracranial tumor radiation therapy. Materials and Methods: Totally 10 treated patients of intracranial tumors were re-planned to 60 Gy in 30 fractions with VMAT and IMRT using Monaco treatment planning system.We compared DVH, confor-mal index, homogeneity index , treatment time, monitor units, and the dose of organs at risk between the two groups. Results: There was equivalent CI and HI {P >0.05), VMAT significantly reduced treatment time and monitor units (P<0.05). To the the dose of organs at risk, the mean of brainstem and optic chiasm were similar (P>0.05), while the men of optic nerve, retina, lens, and the normal brain ,VMAT significantly lower than the IMRT group (P<0.05). Conclusions: Compared with IMRT, VMAT achieves better OAR sparing while using fewer monitor units and less time to treat intracranial tumor.%目的:比较脑胶质瘤术后容积旋转调强(Volumetric Modulated Arc Therapy,VMAT)计划与静态调强(Intensity Modulated Radiation Therapy,IMRT)计划,讨论VMAT的剂量学特性,分析VMAT在脑胶质瘤术后放射治疗中的应用.材料与方法:选取10例颅内肿瘤患者,采用Monaco治疗计划系统,分别制作VMAT计划与IMRT计划,处方剂量全部为PTV:60 Gy/30f.比较两组计划的剂量分布图、DVH图、适形度指数(CI)、均匀指数(HI)、治疗时间、治疗跳数(MU)、危及器官受量.结果:两组计划靶区剂量分布及适形度均较好,CI、HI数相近(P>0.05),但VMAT组的治疗时间和MU均优于IMRT组(P<0.05).在危及器官受量方面,两组计划的脑干与视交叉的平均剂量相近(P>0.05),而视神经、视网膜、晶体和周围正常脑组织的平均剂量,VMAT组明显低于IMRT组(P<0.05).结论:在脑胶质瘤术后的放射治疗中,VMAT与IMRT的靶区剂量分布相近.VMAT的优势在于大大缩小缩短治疗时间、减少MU,同时减少了部分危及器官受量.

  10. Arc binary intensity modulated radiation therapy (AB IMRT)

    Science.gov (United States)

    Yang, Jun

    The state of the art Intensity Modulate Radiation Therapy (IMRT) has been one of the most significant breakthroughs in the cancer treatment in the past 30 years. There are two types of IMRT systems. The first system is the binary-based tomotherapy, represented by the Peacock (Nomos Corp) and Tomo unit (TomoTherapy Inc.), adopting specific binary collimator leafs to deliver intensity modulated radiation fields in a serial or helical fashion. The other uses the conventional dynamic multileaf collimator (MLC) to deliver intensity modulated fields through a number of gantry positions. The proposed Arc Binary IMRT attempts to deliver Tomo-like IMRT with conventional dynamic MLC and combines the advantages of the two types of IMRT techniques: (1) maximizing the number of pencil beams for better dose optimization, (2) enabling conventional linear accelerator with dynamic MLC to deliver Tomo-like IMRT. In order to deliver IMRT with conventional dynamic MLC in a binary fashion, the slice-by-slice treatment with limited slice thickness has been proposed in the thesis to accommodate the limited MLC traveling speed. Instead of moving the patient to subsequent treatment slices, the proposed method offsets MLC to carry out the whole treatment, slice by slice sequentially, thus avoid patient position error. By denoting one arc pencil beam set as a gene, genetic algorithm (GA) is used as the searching engine for the dose optimization process. The selection of GA parameters is a crucial step and has been studied in depth so that the optimization process will converge with reasonable speed. Several hypothetical and clinical cases have been tested with the proposed IMRT method. The comparison of the dose distribution with other commercially available IMRT systems demonstrates the clear advantage of the new method. The proposed Arc Binary Intensity Modulated Radiation Therapy is not only theoretically sound but practically feasible. The implementation of this method would expand the

  11. Study of Intensity-modulated Radiotherapy Planning Optimization Method in the Parallel Organs of Parotid Gland%探讨调强放疗计划中并行器官腮腺的优化方法

    Institute of Scientific and Technical Information of China (English)

    蒋明华; 高艳; 王静; 汪琪; 缪咏梅; 翟振宇

    2012-01-01

    目的:在鼻咽癌调强计划设计中,尝试克服物理约束的局限性,通过改变腮腺的优化条件,使腮腺受照量达到RTOG规定的要求且既不影响靶区剂量.方法:对12例已实施调强放疗的鼻咽癌患者的腮腺进行全部(包括被靶区包绕的深叶腮腺组织)和部分(指靶区外的腮腺组织)勾画,在30%、50%和75%腮腺体积处设置目标剂量和不同权重,对优化计算过的靶区和腮腺所产生的剂量分布,通过结构评估和DVH直方图,定量分析腮腺受照剂量及对靶区的影响.结果:同样的优化条件对部分腮腺体积和全部腮腺优化时,部分腮腺体积优化的D50、MD均大于按全部体积优化的结果.对全部腮腺按不同权重优化得出的结果显示,各靶区98%的体积基本达到98%的处方剂量,但在腮腺优化权重增加到2倍时,CTV2的剂量会降低2%左右,靶区外热点会转移至上颌骨处,靶区适形度略差.但可以使得腮腺MD≤26 Gy;而把权重增加到1.2和1.6倍优化时,都可以使腮腺D50<28 Gy,MD≤30 Gy,V20都大于70%以上.结论:要按全部腮腺体积优化,加大无重叠区腮腺的剂量权重1.2~1.6倍左右,既可保证靶区剂量符合要求又可使得腮腺D50≤28 Gy(符合RTOG一个标准),MD≤30 Gy.%Objective: In nasopharyngeal carcinoma (NPC) IMRT plan design.to try to overcome the physical constraints and limitations,by changingthe optimum conditions of the parotid gland,parotid amount reached RTOG requirements and does not affect the dose of the target area. Methods: 12 cases has been the implementation of intensity-modulated radiontherapy in pa-tiens with NPC ,The parotid gland contoured are all (including the target zone around the deep lobe of parotid gland tissue) and part (parotid gland outside target volume). Set target dose and different weights in 30%,50% and 75% with the parotid gland volume .After optimiztion and calculation,by structural assessment and DVH to target

  12. 食管癌两种旋转调强放疗技术剂量学对比研究%Dosimetric study of two intensity-modulated arc radiotherapy in esophageal cancer

    Institute of Scientific and Technical Information of China (English)

    张若辉; 樊晓妹; 白文文; 李润霄; 曹彦坤; 韩春; 迟子锋

    2014-01-01

    Objective Comparing the dosimetric characteristics of volumetric modulated arc therapy (VMAT) and constant dose rate intensity modulated arc therapy (IMAT) in esophagus cancer to evaluate the performance of the two different arc therapy delivery techniques.Methods 22 cases of esophageal cancer patients were selected for the planning comparison study.All plans were done for IMAT and VMAT treatment plans on Oncentra 4.1 treatment planning system,prescription dose of 2 Gy in total 30 fractions.Planning objectives for PTV were at least 95% reached the prescription dose and V110 no more than 10%.The maximum dose of spinalcord below 45 Gy and double lung dose V20 ≤ 28%,V30 ≤ 18% were constrained.Plans were evaluated based on the ability to meet the dose volume histogram.The dose homogeneity index (HI),radiation conformity index (CI),radiation delivery time,monitor units and γ pass rate were also compared.SPSS 19.0 software paired ttest analysis was carried out on the two sets of data.Results The results showed that the IMAT plans in terms of the PTV's CI (t =3.35,P=0.003),D2(t =-2.27,P=0.034) lung's V30(t =-2.46,P=0.023) were better than that of VMAT group.But the VMAT plans spinal's V40 (t =2.37,P =0.027),lung's V5 (t =2.43,P =0.024) were superior to that of IMAT plans.There were no significant differences between IMAT and VMAT plans in the average dose of PTV,CTV,GTV,heart,spinal cord,double lung and the γpass rate.Conclusion IMAT presents a slight improvement in the OAR sparing in high dose with shorter treatment time when compared to VMAT.While in terms of delivered MU and tissue of low dose irradiated area is higher than that of in VMAT.These two treatment methods all can meet the clinical demand,which should be selected according to the actual situation of the patient.%目的 通过比较食管癌容积旋转调强放疗(VMAT)与固定剂量率旋转调强放疗(IMAT)计划,分析VMAT与IMAT在剂量学方面的特点.方法 对入组的22例

  13. Sensitivity of passing rates of intensity-modulated radiotherapy plans in dose verification against gantry angle errors%IMRT计划剂量验证通过率对机架角度误差灵敏度分析

    Institute of Scientific and Technical Information of China (English)

    王宁; 王彬; 陈阿龙; 黄晓延

    2016-01-01

    Objective To analyze the sensitivity of passing rates of intensity modulated radiation therapy (IMRT) plans in dose verification against gantry angle errors. Methods Gantry angle errors ( ± 2. 0°, ±1. 0°, and ±0. 5°) were introduced into the clinical IMRT plans of 9 patients. There were 7 IMRT plans for each patient, containing 1 original IMRT plan and 6 IMRT plans with gantry angle errors. The dose distribution of the original and modified plans for each patient was measured by ArcCHECK array. Based on the dose distribution of the original plan, the passing rate of each plan was calculated using absolute distance to agreement ( DTA ) analysis and Gamma analysis with the criteria of 3%/3 mm and 2%/2 mm. The obtained passing rates were analyzed by non-parametric Wilcoxon rank test. Results Under the criteria of 3%/3 mm, the mean passing rate in 9 original IMRT plans was 95. 2% using DTA analysis and 96. 5%using Gamma analysis. According to Gamma analysis, the plans with gantry angle errors of-2. 0°,2. 0°, 1. 0° ,-0. 5° , and 0. 5° had the mean passing rates decreased by 12. 2%, 23. 5%, 6. 3%, 0. 9%, and 2. 9%, respectively ( P=0. 008,0. 008,0. 008,0. 036,0. 012) . According to DTA analysis, the above plans had the mean passing rates decreased by 16. 2%, 23. 8%, 1. 7%, 6. 8%, and 3%, respectively ( all P=0. 008) . The passing rates calculated by DTA method were more sensitive to the gantry angle errors than those by Gamma method, while the passing rates under the criterion of 2%/2 mm were more sensitive than those under the criterion of 3%/3 mm. Conclusions The greater the gantry angle errors, the larger the decrease in the mean passing rate. IMRT dose verification is even sensitive enough to detect the gantry angle errors within 0. 5° . Enhanced quality control and assurance of gantry angle is needed to guarantee the accuracy of IMRT delivery.%目的 分析患者IMRT计划剂量验证通过率对机架角度误差的灵敏度.方法 选取9例IMRT计

  14. Esophageal wall dose-surface maps do not improve the predictive performance of a multivariable NTCP model for acute esophageal toxicity in advanced stage NSCLC patients treated with intensity-modulated (chemo-)radiotherapy

    Science.gov (United States)

    Dankers, Frank; Wijsman, Robin; Troost, Esther G. C.; Monshouwer, René; Bussink, Johan; Hoffmann, Aswin L.

    2017-05-01

    In our previous work, a multivariable normal-tissue complication probability (NTCP) model for acute esophageal toxicity (AET) Grade  ⩾2 after highly conformal (chemo-)radiotherapy for non-small cell lung cancer (NSCLC) was developed using multivariable logistic regression analysis incorporating clinical parameters and mean esophageal dose (MED). Since the esophagus is a tubular organ, spatial information of the esophageal wall dose distribution may be important in predicting AET. We investigated whether the incorporation of esophageal wall dose-surface data with spatial information improves the predictive power of our established NTCP model. For 149 NSCLC patients treated with highly conformal radiation therapy esophageal wall dose-surface histograms (DSHs) and polar dose-surface maps (DSMs) were generated. DSMs were used to generate new DSHs and dose-length-histograms that incorporate spatial information of the dose-surface distribution. From these histograms dose parameters were derived and univariate logistic regression analysis showed that they correlated significantly with AET. Following our previous work, new multivariable NTCP models were developed using the most significant dose histogram parameters based on univariate analysis (19 in total). However, the 19 new models incorporating esophageal wall dose-surface data with spatial information did not show improved predictive performance (area under the curve, AUC range 0.79-0.84) over the established multivariable NTCP model based on conventional dose-volume data (AUC  =  0.84). For prediction of AET, based on the proposed multivariable statistical approach, spatial information of the esophageal wall dose distribution is of no added value and it is sufficient to only consider MED as a predictive dosimetric parameter.

  15. Tumour-host dynamics under radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Placeres Jimenez, Rolando, E-mail: rpjcu@yahoo.com [Departamento de Fi' sica, Universidade Federal de Sao Carlos, Sao Carlos - SP (Brazil); Ortiz Hernandez, Eloy [Centre of Medicine and Complexity, Medical University Carlos J. Finlay, Carretera Central s/n, Camagueey (Cuba)

    2011-09-15

    Highlight: > Tumour-host interaction is modelled by Lotka-Volterra equations. > A brief review of the motion integral and analysis of linear stability is presented. > Radiotherapy is introduced into the model, using a periodic Dirac delta function. > A two-dimensional logistic map is derived from the modified Lotka-Volterra model. > It is shown that tumour can be controlled by a correct selection of therapy strategy. - Abstract: Tumour-host interaction is modelled by the Lotka-Volterra equations. Qualitative analysis and simulations show that this model reproduces all known states of development for tumours. Radiotherapy effect is introduced into the model by means of the linear-quadratic model and the periodic Dirac delta function. The evolution of the system under the action of radiotherapy is simulated and parameter space is obtained, from which certain threshold of effectiveness values for the frequency and applied doses are derived. A two-dimensional logistic map is derived from the modified Lotka-Volterra model and used to simulate the effectiveness of radiotherapy in different regimens of tumour development. The results show the possibility of achieving a successful treatment in each individual case by employing the correct therapeutic strategy.

  16. Comparing two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the hypofractionated treatment of high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Yartsev Slav

    2008-01-01

    Full Text Available Abstract Background To compare two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the setting of hypofractionated high-risk prostate cancer treatment. Methods 3DCRT and dIMRT/Helical Tomotherapy(HT planning with 10 CT datasets was undertaken to deliver 68 Gy in 25 fractions (prostate and simultaneously delivering 45 Gy in 25 fractions (pelvic lymph node targets in a single phase. The paradigms of pelvic vessel targeting (iliac vessels with margin are used to target pelvic nodes and conformal normal tissue avoidance (treated soft tissues of the pelvis while limiting dose to identified pelvic critical structures were assessed compared to 3DCRT controls. Both dIMRT/HT and 3DCRT solutions were compared to each other using repeated measures ANOVA and post-hoc paired t-tests. Results When compared to conformal pelvic vessel targeting, conformal normal tissue avoidance delivered more homogenous PTV delivery (2/2 t-test comparisons; p dose, 1–3 Gy over 5/10 dose points; p Conclusion dIMRT/HT nodal and pelvic targeting is superior to 3DCRT in dose delivery and critical structure sparing in the setting of hypofractionation for high-risk prostate cancer. The pelvic targeting paradigm is a potential solution to deliver highly conformal pelvic radiation treatment in the setting of nodal location uncertainty in prostate cancer and other pelvic malignancies.

  17. T1-2 N0-1 M0期乳腺癌保乳术后大分割调强放疗近期临床观察%The retrospective study of hypofractionated intensity -modulated radiotherapy in breast cancer after breast conserving surgery with stage T1-2N0-1M0

    Institute of Scientific and Technical Information of China (English)

    景娜; 王玉; 杨君; 王仙玲; 马永强

    2015-01-01

    Objective:To observe the efficacy,cosmetic outcome and adverse reaction of hypofractionated intensity-modulated radiotherapy for T1 -2 N0 -1 M0 breast cancer after breast conserving surgery.Methods:From November 2011 to November 2012,41 patients with T1 -2 N0 -1 M0 breast cancer after breast conserving surgery in Shanxi Tumor Hospital were enrolled in the trial.The hypofractionated intensity -modulated radiotherapy was applied to each pa-tient.The hypofractionated intensity -modulated radiotherapy was 43.5Gy/(15f·3w)to the whole breast,with a boost of 8.7Gy/(3f·3d)to the tumor bed.The dose was 2.9Gy per fraction,the total course of treatment was 24 days.Locoregional control and overall survival were calculated by Kaplan -Meier method.Results:The follow -up rate was 100%,the 3 -year locoregional control and overall survival were both 100%.4 developed grade Ⅰ acute ra-diodermatitis,3 developed grade Ⅱ acute radiodermatitis,5 developed grade Ⅰ leukocyte reduction,3 developed grade Ⅱ leukocyte reduction,2 developed grade Ⅲ leukocyte reduction,2 developed grade Ⅰ acute radioactive pneu-monia,1 developed grade late radioactive pneumonia,2 developed grade Ⅰ limb edema.The excellent and good rates of cosmetic outcomes before and after radiotherapy were 95.1%,87.8%,The 1 -,3 -,6 -,12 -month excellent and good rates of cosmetic outcomes after radiotherapy were 90.2%.Conclusion:The hypofractionated intensity -modula-ted radiotherapy for the patients with early -stage breast cancer after breast -conserving surgery have good therapeu-tic effects and cosmetic results,acceptable toxicities,low adverse reaction,as well as can shorten the time of radiother-apy.%目的:观察 T1-2 N0-1 M0期乳腺癌保乳术后大分割调强放疗的疗效、美容效果及不良反应。方法:选择2011年11月-2012年11月间就诊于山西省肿瘤医院乳腺疾病诊治中心的乳腺癌保乳患者41例,予大分割调强放疗,全乳计划靶体积43.5Gy

  18. 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

  19. Upper bound of Ⅱb region in clinical target volume for intensity-modulated radiotherapy for nasopharyngeal carcinoma%鼻咽癌IMRT的CTV中Ⅱb区上界的探讨

    Institute of Scientific and Technical Information of China (English)

    王丽君; 郭业松; 张兰芳; 黄生富; 何侠; 张宜勤

    2016-01-01

    目的:探讨鼻咽癌IMRT的CTV中Ⅱb 区的上界,并寻找个体化缩减Ⅱb 区范围的标准。方法回顾分析2012—2014年收治的142例( AJCC 2010分期标准Ⅰ、Ⅱ、Ⅲ、Ⅳ期分别为8、37、41、56例)初治鼻咽癌患者采用IMRT情况。根据影像阅片研究鼻咽癌颈部淋巴结分布规律。比较缩减Ⅱb 区范围者与未缩减者腮腺剂量参数差异并t检验及t'检验。结果咽后外侧淋巴结和Ⅱb 区淋巴结是最常见受累淋巴结,转移率分别为75�4%和67�6%。在Ⅱb 区受累患者中51�0%出现了高位阳性淋巴结,6�3%阳性淋巴结上界超过了RTOG分区定义的Ⅱb 区上界。对符合拟定标准患者缩减Ⅱb 区范围是安全的,优化靶区后可显著降低腮腺D50、V26( P=0�000)。结论在勾画鼻咽癌颈部CTV时,原则上Ⅱb 区上界应至侧颅底,但对符合拟定标准者可个体化缩减Ⅱb 区上界,以更好地保护腮腺。%Objective To explore the upper bound of Ⅱb region in the clinical target volume ( CTV ) for intensity⁃modulated radiotherapy ( IMRT ) for nasopharyngeal carcinoma ( NPC ) , and to establish a standard for personalized reduction in the range ofⅡb region. Methods A retrospective analysis was performed on the IMRT results of 142 patients newly diagnosed with NPC who were admitted to our hospital from 2012 to 2014. According to the American Joint Committee on Cancer 2010 staging system, there were 8 patients with stageⅠ disease, 37 stage Ⅱ, 41 stage Ⅲ, and 56 stage Ⅳ. The distribution pattern of cervical lymph nodes in NPC was studied based on the imaging results. Comparison of the dose to parotid glands between patients with and without reduction in the range ofⅡb region was made by t test and t'test. Results The metastasis rates of the most common diseased lymph nodes, lateral retropharyngeal lymph node and Ⅱb lymph node, were 75�4% and 67�6%, respectively. In the patients

  20. Trajectory optimization for dynamic couch rotation during volumetric modulated arc radiotherapy

    Science.gov (United States)

    Smyth, Gregory; Bamber, Jeffrey C.; Evans, Philip M.; Bedford, James L.

    2013-11-01

    Non-coplanar radiation beams are often used in three-dimensional conformal and intensity modulated radiotherapy to reduce dose to organs at risk (OAR) by geometric avoidance. In volumetric modulated arc radiotherapy (VMAT) non-coplanar geometries are generally achieved by applying patient couch rotations to single or multiple full or partial arcs. This paper presents a trajectory optimization method for a non-coplanar technique, dynamic couch rotation during VMAT (DCR-VMAT), which combines ray tracing with a graph search algorithm. Four clinical test cases (partial breast, brain, prostate only, and prostate and pelvic nodes) were used to evaluate the potential OAR sparing for trajectory-optimized DCR-VMAT plans, compared with standard coplanar VMAT. In each case, ray tracing was performed and a cost map reflecting the number of OAR voxels intersected for each potential source position was generated. The least-cost path through the cost map, corresponding to an optimal DCR-VMAT trajectory, was determined using Dijkstra’s algorithm. Results show that trajectory optimization can reduce dose to specified OARs for plans otherwise comparable to conventional coplanar VMAT techniques. For the partial breast case, the mean heart dose was reduced by 53%. In the brain case, the maximum lens doses were reduced by 61% (left) and 77% (right) and the globes by 37% (left) and 40% (right). Bowel mean dose was reduced by 15% in the prostate only case. For the prostate and pelvic nodes case, the bowel V50 Gy and V60 Gy were reduced by 9% and 45% respectively. Future work will involve further development of the algorithm and assessment of its performance over a larger number of cases in site-specific cohorts.

  1. 图像引导大分割调强放疗同步化疗治疗局部晚期非小细胞肺癌的临床研究∗%An Analysis of Local Advanced Non-small Cell Lung Cancer Treated with Image-guided Hypofractionated Intensity Modulated Radiotherapy combined with Chemotherapy

    Institute of Scientific and Technical Information of China (English)

    吕家华; 李涛; 李昉; 王奇峰; 刘丽; 李厨荣; 宋宴琼

    2015-01-01

    Objective: To observe the efficacy and the toxicity of the image-guided intensity modulated hypofrac-tionated radiotherapy combined with chemotherapy for the treatment of local advanced non-small cell lung cancer (NSCLC). Methods: From August 2011 to April 2013, 44 patients with local advanced non-small cell lung cancer(Stage IIIA:20 pts,Stage IIIB:24 pts) were treated with image-guided intensity modulated hypofractionated radiotherapy combined with chemotherapy. A total dose of 60Gy ~ 72Gy was given to the planning target volume (PTV) of thoracic primary tumor. Hypofractionated radiotherapy scheme was 3Gy ~ 8Gy/ f/ d,3 ~ 5f/ w. All patients received at least 2 cycles of concurrent platinum-based double medicine combination chemotherapy. Results: The response rate was 81. 8% . A complete response was achieved in 7 patients (15. 9% ), and 29 patients (65. 9% ) achieved a partial response. The 1-, 2-year overall sur-vival rate (OS) and median survival time (MST) were 79. 5% , 51. 3% and 25 months, respectively. The 1-, 2-year local control rates (LCR) were 86. 4% and 59. 1% . The 1-, 2-year progression-free survival (PFS) and median progression-free survival were 61. 2% , 38. 7% and 18 months, respectively. The incidence rates of grade 3 + acute radiation pneumo-nitis and radiation esophagitis were 6. 8% and 9. 1% . The main chemotherapy-induced acute toxic reactions were bone marrow depression ( grade 3 + ) included 17 patients ( 38. 6% ) with leukopenia, 3 patients ( 6. 8% ) with anemia, 6 patients (13. 6% ) with thrombocytopenia. Con-clusion: Image-guided intensity modulated hypofractionated radiotherapy combined with chemotherapy is safe and results in excellent local control and survival for local advanced NSCLC with tolerable toxicity.%目的::探讨图像引导大分割调强放疗同步化疗治疗局部晚期非小细胞肺癌(NSCLC)的疗效和毒副反应。方法:2011年8月至2013年4月,44例局部晚期 NSCLC 患者(ⅢA 期20例,ⅢB 期24例)

  2. Multimodal hypoxia imaging and intensity modulated radiation therapy for unresectable non-small-cell lung cancer: the HIL trial

    Directory of Open Access Journals (Sweden)

    Askoxylakis Vasileios

    2012-09-01

    Full Text Available Abstract Background Radiotherapy, preferably combined with chemotherapy, is the treatment standard for locally advanced, unresectable non-small cell lung cancer (NSCLC. The tumor response to different therapy protocols is variable, with hypoxia known to be a major factor that negatively influences treatment effectiveness. Visualisation of tumor hypoxia prior to the use of modern radiation therapy strategies, such as intensity modulated radiation therapy (IMRT, might allow optimized dose applications to the target volume, leading to improvement of therapy outcome. 18 F-fluoromisonidazole dynamic positron emission tomography and computed tomography (18 F-FMISO dPET-CT and functional magnetic resonance imaging (functional MRI are attractive options for imaging tumor hypoxia. Methods/design The HIL trial is a single centre study combining multimodal hypoxia imaging with 18 F-FMISO dPET-CT and functional MRI, with intensity modulated radiation therapy (IMRT in patients with inoperable stage III NSCLC. 15 patients will be recruited in the study. All patients undergo initial FDG PET-CT and serial 18 F-FMISO dPET-CT and functional MRI before treatment, at week 5 of radiotherapy and 6 weeks post treatment. Radiation therapy is performed as inversely planned IMRT based on 4D-CT. Discussion Primary objectives of the trial are to characterize the correlation of 18 F-FMISO dPET-CT and functional MRI for tumor hypoxia imaging in NSCLC and evaluate possible effects of radiation therapy on tumor re-oxygenation. Further objectives include the generation of data regarding the prognostic value of 18 F-FMISO dPET-CT and functional MRI for locoregional control, progression free survival and overall survival of NSCLC treated with IMRT, which will form the basis for larger clinical trials focusing on possible interactions between tumor oxygenation and radiotherapy outcome. Trial registration The ClinicalTrials.gov protocol ID is NCT01617980

  3. Analysis and simulation of XPM intensity modulation

    Institute of Scientific and Technical Information of China (English)

    Jing Huang; Jianquan Yao

    2005-01-01

    Based on the split-step Fourier method and small signal analysis, an improved analytical solution which describes the cross-phase modulation (XPM) intensity is derived. It can suppress the spurious XPM intensity modulation efficiently in the whole transmission fiber. Thus it is more coincidence with the practical result. Furthermore, it is convenient, because it is independent of channel separation and the dispersion and nonlinear effects interact through the XPM intensity. A criterion of select the step size is described as the derived XPM intensity modulation being taken into account. It is non-uniform distribution method, the simulation accuracy is improved when the step size is determined by the improved XPM intensity.

  4. The Fix Effects and Accuracy of the Head, Neck and Shoulder Mask in Intensity-modulated Radiotherapy of Nasopharyngeal Carcinoma%头颈肩面罩在鼻咽癌调强放疗中的固定效果与精度比较

    Institute of Scientific and Technical Information of China (English)

    赵家成; 李多杰; 段诗苗; 沈学明

    2012-01-01

    Objective To study the fix effects and accuracy of the head, neck and shoulder mask in intensity-modulated radiotherapy of nasopharyngeal carcinoma in order to provide reference for reasonably using the head, neck and shoulder mask. Methods Head,neck and shoulder mask was applied in 18 cases of nasopharyngeal carcinoma in the intensity-modulated radiotherapy , the DRR diagram output from treatment planning system with symbol of osteoarthritis of simulation validation film in the second weekend, fourth and sixth weekend were compared. Results The overall set-up error in 18 patients in three directions were(1.03 ±0.69) mm in the left and right(X) direction, (1.09 ±0.65)mm in the head and foot(Y)direction, (0. 81 ±0:54) mm in the anterior and posterior(Z) direction. The difference between the sixth week and the second week was statistically significant (P <0. 05) . Conclusion The head,neck and shoulder mask may improve the precision of set-up,but the accuracy of the sixth week was down regulated.%目的 探讨头颈肩面罩在鼻咽癌调强放疗中的固定效果及前后期的固定精度的比较,为合理使用头颈肩面罩提供参考.方法 选取鼻咽癌调强放疗的患者18例,头颈肩面罩固定,分别在放疗的第2周末、第4周末和第6周末在模拟定位机房拍摄验证片,采用验证片上的骨性标志与治疗计划系统输出的DRR图进行比较,记录其摆位误差.结果 18例患者在各个方向上的总体摆位误差分别为X轴左右方向(1.03±0.69)mm,Y轴头脚方向(1.09±0.65)mm,Z轴前后方向(0.81±0.54)mm,第6周与第2周相比差异有统计学意义(P<0.05).结论 头颈肩面罩有很好的体位固定效果,放疗的第6周末精度有所下降.

  5. Development of a Standardized Method for Contouring the Lumbosacral Plexus: A Preliminary Dosimetric Analysis of this Organ at Risk Among 15 Patients Treated With Intensity-Modulated Radiotherapy for Lower Gastrointestinal Cancers and the Incidence of Radiation-Induced Lumbosacral Plexopathy

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Sun K., E-mail: sun.yi@ucdmc.ucdavis.edu [Department of Radiation Oncology, University of California, Davis Cancer Center, Sacramento, CA (United States); Mak, Walter [Department of Radiology, University of California, Davis Medical Center, Sacramento, CA (United States); Yang, Claus C.; Liu Tianxiao [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS (United States); Cui Jing; Chen, Allen M.; Purdy, James A.; Monjazeb, Arta M. [Department of Radiation Oncology, University of California, Davis Cancer Center, Sacramento, CA (United States); Do, Ly [Cancer Care Institute, San Jose, CA (United States)

    2012-10-01

    Purpose: To generate a reproducible step-wise guideline for the delineation of the lumbosacral plexus (LSP) on axial computed tomography (CT) planning images and to provide a preliminary dosimetric analysis on 15 representative patients with rectal or anal cancers treated with an intensity-modulated radiotherapy (IMRT) technique. Methods and Materials: A standardized method for contouring the LSP on axial CT images was devised. The LSP was referenced to identifiable anatomic structures from the L4-5 interspace to the level of the sciatic nerve. It was then contoured retrospectively on 15 patients treated with IMRT for rectal or anal cancer. No dose limitations were placed on this organ at risk during initial treatment planning. Dosimetric parameters were evaluated. The incidence of radiation-induced lumbosacral plexopathy (RILSP) was calculated. Results: Total prescribed dose to 95% of the planned target volume ranged from 50.4 to 59.4 Gy (median 54 Gy). The mean ({+-}standard deviation [SD]) LSP volume for the 15 patients was 100 {+-} 22 cm{sup 3} (range, 71-138 cm{sup 3}). The mean maximal dose to the LSP was 52.6 {+-} 3.9 Gy (range, 44.5-58.6 Gy). The mean irradiated volumes of the LSP were V40Gy = 58% {+-} 19%, V50Gy = 22% {+-} 23%, and V55Gy = 0.5% {+-} 0.9%. One patient (7%) was found to have developed RILSP at 13 months after treatment. Conclusions: The true incidence of RILSP in the literature is likely underreported and is not a toxicity commonly assessed by radiation oncologists. In our analysis the LSP commonly received doses approaching the prescribed target dose, and 1 patient developed RILSP. Identification of the LSP during IMRT planning may reduce RILSP. We have provided a reproducible method for delineation of the LSP on CT images and a preliminary dosimetric analysis for potential future dose constraints.

  6. Phase Ⅱ Study of Intensity-Modulated Radiotherapy Combined with 5-Fluorouracil and Nedaplatin Chemotherapy in Recurrent Esophageal Carcinoma after Curative Operation%食管癌术后复发患者调强放疗同步化疗(5-Fu+奈达铂)的Ⅱ期临床研究

    Institute of Scientific and Technical Information of China (English)

    陶华; 孔诚; 陆进成

    2012-01-01

    Objective To analyze the feasibility and safety of postoperative recurrent esophageal carcinoma patients treated by intensity-modulated radiotherapy combined with 5-Fluorouracil(5-Fu) and nedaplatin chemotherapy. Methods Forty-four esophageal carcinoma patients suffered recurrence after their definitive resection in our department from June 2009 to June 2010. Intensity-modulated radiotherapy combined with 5-Fu and nedaplatin chemotherapy was performed in the patients(gross tumor volume,GTV) of IMRT was prescribed to 60 Gy/ 30f ,2. 0 Gy/f and 5-Fu and nedaplatin concurrent chemotherapy was used by 5-Fu 750 mg/(m2 · d),dl — 5, nedaplatin 80 mg/(m2 · d),dl at week 1 and week 4. The primary endpoint was 1-year survival rate and the second endpoint was toxicity related to the treatment. Results The overall response rate (CR + PR) was 86% (38/44). 1- and 2-year overall survival rate was 72. 7% and 60% , respectively. 1- and 2-year progression-free survival rate was 63. 6% and 36. 6% , respectively. Univariate analysis outcome showed that only recurrent site was related with prognosis (X2 = 22. 848,P = 0. 000). All the patients undergone this treatment smoothly. Grade T , D and III leukocytopenia was observed in 16% (7/44),50% (22/44),and 34% (15/44) patients,respectively. Grade Land II digestive tract toxicity was observed in 45% (20/44),55% (24/44) patients,respectively. Grade T ,and II liver/renal toxicity was observed in 77% (34/44) ,and 23% (10/44) patients,respectively. Over grade 3 digestive tract and liver/renal toxicity were not found. All the toxicities were gone after corresponding therapy. Conclusion Concurrent chemotherapy with 5-Fu and nedaplatin plus intensity-modulated radiotherapy is an effective and feasible regimen and would be considered as a better option for postoperative recurrent esophageal carcinoma patients, which could be deserved to be applied to phase III clinical trial.%目的 评价食管癌根治术后复发

  7. Stromal-epithelial dynamics in response to fractionated radiotherapy

    Science.gov (United States)

    Qayyum, Muqeem Abdul

    signaling in post-surgical breast cancer recurrence would be to assist radiation oncologists in designing an improved therapeutic strategy. To relate the parameters of cellular function to therapeutic prescriptions which offer an enhanced clinical outcome would address the lack of knowledge regarding recurrence of disease, tumor control and whether the tumor microenvironment requires more aggressive treatments. In our work to date, we have developed a three-dimensional co-culture model to determine how alternative dose fractionations affect the post-surgical microenvironment. This work suggests that 3-D co-cultures provide the microenvironmental cues needed to reexamine the radiobiological basis underlying radiation therapy. The findings suggest dose escalation to the tumor region may deactivate the reactive stroma, thus minimizing the cancer promoting environment. Large-fraction irradiation may be used to sterilize residual tumor cells and inhibit activation of intracellular transduction pathways that are promoted during the post-surgical wound-healing period. Wound-healing mechanisms are characterized by angiogenesis, fibroplasia, collagen production and granulation tissue formation all of which impact patient prognosis. In fact, tumor dose escalation trials have been proven to reduce local recurrence rates and thus new approaches to partial breast irradiation and tumor bed boosting using external-beam electrons and intensity-modulated radiotherapy (IMRT) techniques are currently under use. These techniques minimize absorbed dose to healthy breast tissues. Treating the residual cancer cells and the reactive stroma that has been stimulated by wound healing requires that we look at the interplay between cell types as well as the mechanical and biochemical factors driving disease. We have discovered that the reason hypofractionation schemes (larger irradiation fractions per day with less total dose) offer therapeutic advantages to some patients could be that it is more

  8. Metadevice for intensity modulation with sub-wavelength spatial resolution

    CERN Document Server

    Cencillo-Abad, Pablo; Plum, Eric

    2016-01-01

    Effectively continuous control over propagation of a beam of light requires light modulation with pixelation that is smaller than the optical wavelength. Here we propose a spatial intensity modulator with sub-wavelength resolution in one dimension. The metadevice combines recent advances in reconfigurable nanomembrane metamaterials and coherent all-optical control of metasurfaces. It uses nanomechanical actuation of metasurface absorber strips placed near a mirror in order to control their interaction with light from perfect absorption to negligible loss, promising a path towards dynamic beam diffraction, light focusing and holography without unwanted diffraction artefacts.

  9. Radiosurgery of small skull-base lesions. No advantage for intensity-modulated stereotactic radiosurgery versus conformal arc technique

    Energy Technology Data Exchange (ETDEWEB)

    Ernst-Stecken, A.; Sauer, R.; Grabenbauer, G. [Dept. of Radiation Therapy and Novalis Shaped Beam Surgery Center, Univ. of Erlangen-Nuremberg, Erlangen (Germany); Lambrecht, U.; Mueller, R. [Dept. of Radiation Therapy and Novalis Shaped Beam Surgery Center, Univ. of Erlangen-Nuremberg, Erlangen (Germany); Div. of Medical Physics, Dept. of Radiation Therapy, Univ. of Erlangen-Nuremberg, Erlangen (Germany); Ganslandt, O.; Fahlbusch, R. [Dept. of Neurosurgery, Univ. of Erlangen-Nuremberg, Erlangen (Germany)

    2005-05-01

    Background and purpose: intensity-modulated stereotactic radiotherapy (IMSRT) has shown the ability to conform the dose to concavities and to better avoid critical organs for large tumors. Given the availability of an electronically driven micro-multileaf collimator, both intensity-modulated stereotactic radiosurgery (IMSRS) and dynamic conformal arc (DCA) technique (DCA) can be performed at the Novalis Shaped Beam Surgery Center, University of Erlangen-Nuremberg, Germany, since 12/2002. This study evaluates both techniques in small skull-base tumors treated with radiosurgery. Material and methods: between 12/2002 and 04/2004, a total of 109 radiosurgical procedures were performed in 77 patients, equally distributed between patients with acoustic neuroma (AN), pituitary adenoma (PA) and meningeoma (M). Six index patients (n = 2 AN, n = 1 PA, n = 3 M) routinely planned for dynamic arc stereotactic radiosurgery were replanned using the IMSRS approach (BrainScan, BrainLAB, Heimstetten, Germany). The RTOG radiosurgery quality assurance guidelines, isodose volumes, doses to organs at risk (OAR), and dose delivery criteria were compared. Results: DCA was superior to IMSRS for homogeneity and coverage. IMSRS could keep the high-dose-irradiated volumes (90% isodose volume) lower than DCA in the PA and AN with very small volumes, but all other lower dose volumes were larger for IMSRS. Dose maxima to OAR were higher for IMSRS. Treatment delivery time for IMSRS would clearly exceed treatment time for DCA by a factor of 2-3. The integral absorbed dose to the brain was much higher in the IMSRS than in the DCA approach (factor 2-3). Conclusion: RTOG radiosurgery guidelines were best met by the DCA rather than IMSRS approach for the treatment of small skull-base lesions. The IMSRS approach will increase the time for planning, dose delivery and integral dose to the brain. Thus, IMSRT techniques are recommended for fractionated stereotactic radiotherapy to larger volumes rather

  10. 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.

  11. Fan-beam intensity modulated proton therapy

    Science.gov (United States)

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-01-01

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques. Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets. Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage

  12. Similarities between static and rotational intensity-modulated plans

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q Jackie; Yin Fangfang; McMahon, Ryan; Zhu Xiaofeng; Das, Shiva K [Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710 (United States)], E-mail: jackie.wu@duke.edu

    2010-01-07

    The aim of this study was to explore similarities between intensity-modulated radiotherapy (IMRT) and intensity-modulated arc therapy (IMAT) techniques in the context of the number of multi-leaf collimator (MLC) segments required to achieve plan objectives, the major factor influencing plan quality. Three clinical cases with increasing complexity were studied: (a) prostate only, (b) prostate and seminal vesicles and (c) prostate and pelvic lymph nodes. Initial 'gold-standard' plans with the maximum possible organ-at-risk sparing were generated for all three cases. For each case, multiple IMRT and IMAT plans were generated with varying intensity levels (IMRT) and arc control points (IMAT), which translate into varying MLC segments in both modalities. The IMAT/IMRT plans were forced to mimic the organ-at-risk sparing and target coverage in the gold-standard plans, thereby only allowing the target dose inhomogeneity to be variable. A higher target dose inhomogeneity (quantified as D5-dose to the highest 5% of target volume) implies that the plan is less capable of modulation. For each case, given a similar number of MLC segments, both IMRT and IMAT plans exhibit similar target dose inhomogeneity, indicating that there is no difference in their ability to provide dose painting. Target dose inhomogeneity remained approximately constant with decreasing segments, but sharply increased below a specific critical number of segments (70, 100, 110 for cases a, b, c, respectively). For the cases studied, IMAT and IMRT plans are similar in their dependence on the number of MLC segments. A minimum critical number of segments are required to ensure adequate plan quality. Future studies are needed to establish the range of minimum critical number of segments for different treatment sites and target-organ geometries.

  13. Similarities between static and rotational intensity-modulated plans

    Science.gov (United States)

    Wu, Q. Jackie; Yin, Fang-Fang; McMahon, Ryan; Zhu, Xiaofeng; Das, Shiva K.

    2010-01-01

    The aim of this study was to explore similarities between intensity-modulated radiotherapy (IMRT) and intensity-modulated arc therapy (IMAT) techniques in the context of the number of multi-leaf collimator (MLC) segments required to achieve plan objectives, the major factor influencing plan quality. Three clinical cases with increasing complexity were studied: (a) prostate only, (b) prostate and seminal vesicles and (c) prostate and pelvic lymph nodes. Initial 'gold-standard' plans with the maximum possible organ-at-risk sparing were generated for all three cases. For each case, multiple IMRT and IMAT plans were generated with varying intensity levels (IMRT) and arc control points (IMAT), which translate into varying MLC segments in both modalities. The IMAT/IMRT plans were forced to mimic the organ-at-risk sparing and target coverage in the gold-standard plans, thereby only allowing the target dose inhomogeneity to be variable. A higher target dose inhomogeneity (quantified as D5—dose to the highest 5% of target volume) implies that the plan is less capable of modulation. For each case, given a similar number of MLC segments, both IMRT and IMAT plans exhibit similar target dose inhomogeneity, indicating that there is no difference in their ability to provide dose painting. Target dose inhomogeneity remained approximately constant with decreasing segments, but sharply increased below a specific critical number of segments (70, 100, 110 for cases a, b, c, respectively). For the cases studied, IMAT and IMRT plans are similar in their dependence on the number of MLC segments. A minimum critical number of segments are required to ensure adequate plan quality. Future studies are needed to establish the range of minimum critical number of segments for different treatment sites and target-organ geometries.

  14. 三维适形放疗和适形调强放疗技术对鼻咽癌放疗后颞颌关节损伤的影响%Comparison of temporomandibular joint injuries after three-dimensional conformal and intensity-modulated radiotherapies for nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    陈冬平; 余意; 齐斌; 刘锦全; 李铭仪; 梁玉莹

    2012-01-01

    Objective To compare the radiation injuries of the temporomandibular joint (TMJ) following three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma (NPC). Methods Thirty-nine NPC patients without previous radiotherapy underwent 3D-CRT and another 32 received IMRT in our institute. The distance between the 2 dens incisivus medialis (DDIM) and LENT SOMA criteria were employed to evaluate TMJ injuries, clinical outcomes, and the performance-to-price ratios. Results The short-term local response rates were similar between the two groups (P=0.878). The mean radiation doses of the TMJ were significantly higher in 3D-CRT group than in IMRT group (57.06 us 40.90 Gy, P0.05). Conclusion Radiation injuries of the TMJ are tolerable in both 3D-CRT and IMRT groups, and 3D-CRT is a more economic choice for patients who can not afford IMRT.%目的 观察不同放疗方式对患者颞颌关节损伤的影响,为不同条件的患者制定个体化的放疗计划提供参考.方法 回顾性分析71例初治鼻咽癌患者,三维适形放疗(3D-CRT)组39例,适形调强放疗(IMRT)组32例,以门齿距及LENT SOMA标准为评价指标,比较两组之间疗效及性价比.结果 3D-CRT组近期局部控制率与IMRT组无差异(P=0.878);3D-CRT组的颞颌关节受量高于IMRT组(平均57.06 Gy和40.90 Gy,P<0.001);比较两组放疗后1年与放疗前 门齿距差值,3D-CRT组缩小较明显,具有统计学意义(P<0.05);两组患者颞颌关节损伤按SOMA分级标准比较,无统计学差异(P>0 05).结论 相对于IMRT技术来说,3D-CRT技术具有很好的经济优势,颞颌关节的损伤可耐受,3D-CRT技术对于经济条件较差的患者仍是性价比较好的治疗选择.

  15. SU-E-T-309: Dosimetric Comparison of Simultaneous Integrated Boost Treatment Plan Between Intensity Modulated Radiotherapies (IMRTs), Dual Arc Volumetric Modulated Arc Therapy (DA-VMAT) and Single Arc Volumetric Modulated Arc Therapy (SA-VMAT) for Nasopharyngeal Carcinoma (NPC)

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar, R; Janardhan, N; Bhavani, P; Surendran, J; Saranganathan, B; Ibrahim, S; Jhonson, B; Madhuri, B [Omega Hospitals, Hyderabad, Telangana (India); Anuradha, C [Vit University, Vellore, Tamil Nadu (India)

    2015-06-15

    Purpose: To compare the plan quality and performance of Simultaneous Integrated Boost (SIB) Treatment plan between Seven field (7F) and Nine field(9F) Intensity Modulated Radiotherapies and Single Arc (SA) and Dual Arc (DA) Volumetric Modulated Arc Therapy( VMAT). Methods: Retrospective planning study of 16 patients treated in Elekta Synergy Platform (mlci2) by 9F-IMRT were replanned with 7F-IMRT, Single Arc VMAT and Dual Arc VMAT using CMS, Monaco Treatment Planning System (TPS) with Monte Carlo simulation. Target delineation done as per Radiation Therapy Oncology Protocols (RTOG 0225&0615). Dose Prescribed as 70Gy to Planning Target Volumes (PTV70) and 61Gy to PTV61 in 33 fraction as a SIB technique. Conformity Index(CI), Homogeneity Index(HI) were used as analysis parameter for Target Volumes as well as Mean dose and Max dose for Organ at Risk(OAR,s).Treatment Delivery Time(min), Monitor unit per fraction (MU/fraction), Patient specific quality assurance were also analysed. Results: A Poor dose coverage and Conformity index (CI) was observed in PTV70 by 7F-IMRT among other techniques. SA-VMAT achieved poor dose coverage in PTV61. No statistical significance difference observed in OAR,s except Spinal cord (P= 0.03) and Right optic nerve (P=0.03). DA-VMAT achieved superior target coverage, higher CI (P =0.02) and Better HI (P=0.03) for PTV70 other techniques (7F-IMRT/9F-IMRT/SA-VMAT). A better dose spare for Parotid glands and spinal cord were seen in DA-VMAT. The average treatment delivery time were 5.82mins, 6.72mins, 3.24mins, 4.3mins for 7F-IMRT, 9F-IMRT, SA-VMAT and DA-VMAT respectively. Significance difference Observed in MU/fr (P <0.001) and Patient quality assurance pass rate were >95% (Gamma analysis (Γ3mm, 3%). Conclusion: DA-VAMT showed better target dose coverage and achieved better or equal performance in sparing OARs among other techniques. SA-VMAT offered least Treatment Time than other techniques but achieved poor target coverage. DA-VMAT offered

  16. Volumetric Modulated Arc Therapy, Conventional Intensity-modulated Radiotherapy and Three-Dimensional Conformal Techniques for Upper Thoracic Esophageal Cancer: A Planning Comparison Study%胸上段食管癌容积旋转调强和静态调强与三维适形放疗计划的剂量学比较

    Institute of Scientific and Technical Information of China (English)

    张瑞; 习勉; 李巧巧; 赵磊; 黄晓波; 何立儒; 胡永红; 刘孟忠

    2012-01-01

    [目的]比较容积旋转调强( VMAT)、静态调强(sIMRT)与三维适形放疗(3DCRT)技术在胸上段食管癌的剂量学差异.[方法]选取7例局部晚期胸上段食管癌患者,分别制定3DCRT、7野sIMRT和360度单弧VMAT 3套放疗计划,处方剂量统一为60 Gy/30F.比较靶区、危及器官的剂量体积参数,加速器的总机器跳数(MU)和有效治疗时间(TT)等.[结果]VMAT与IMRT的靶区剂量分布基本一致,均优于3DCRT.对于正常组织,三组计划中肺、心脏的受照剂量均无明显差异,但IMRT与VMAT可较3DCRT更好的保护脊髓.3DCRT、IMRT、VMAT的MU分别为537±92、601±122、682±139,有效治疗时间(min)分别为3.9±0.3、6.0±0.7、4.7±0.7 (P< 0.05).[结论]与3DCRT相比,VMAT与IMRT在胸上段食管癌均有一定的剂量学优势,但VMAT较IMRT可显著提高治疗效率.%[Objective] A planning study was performed to compare volumetric modulated arc therapy (VMAT), static intensity-modulated radiotherapy (sIMRT), and three-dimensional conformal radiotherapy (3DCRT) for upper thoracic esophageal cancer. [Methods] Seven patients with loco-regionally advanced upper thoracic esophageal cancer were included. Based on the identical CT and planning target volume (PTV), three plans (3DCRT, sIMRT with seven fields, VMAT with a single arc) were generated. Dose prescription was set to 60Gy in 30 fractions. Dose volume histograms, MU and delivery time were evaluated to assess plan quality. [Results] In comparison to 3DCRT, both VMAT and IMRT provided a systematic improvement in PTV coverage. For normal tissues, equivalent sparing of lung and heart were achieved with three plans. However, IMRT and VMAT showed a superior sparing compared with 3DCRT for spinal cord. The MU/fraction was as follows; 537 ± 92 for 3DCRT, 601 ± 122 for IMRT, and 682 ± 139 for VMAT. Effective treatment time for 3DCRT, IMRT and VMAT were (3.9 ± 0.3) min, (6.0 ± 0.7) min and (4.7 ± 0.7)min, respectively (P< 0

  17. Intensity modulated radiation therapy for breast cancer: current perspectives

    Science.gov (United States)

    Buwenge, Milly; Cammelli, Silvia; Ammendolia, Ilario; Tolento, Giorgio; Zamagni, Alice; Arcelli, Alessandra; Macchia, Gabriella; Deodato, Francesco; Cilla, Savino; Morganti, Alessio G

    2017-01-01

    Background Owing to highly conformed dose distribution, intensity modulated radiation therapy (IMRT) has the potential to improve treatment results of radiotherapy (RT). Postoperative RT is a standard adjuvant treatment in conservative treatment of breast cancer (BC). The aim of this review is to analyze available evidence from randomized controlled trials (RCTs) on IMRT in BC, particularly in terms of reduction of side effects. Methods A literature search of the bibliographic database PubMed, from January 1990 through November 2016, was performed. Only RCTs published in English were included. Results Ten articles reporting data from 5 RCTs fulfilled the selection criteria and were included in our review. Three out of 5 studies enrolled only selected patients in terms of increased risk of toxicity. Three studies compared IMRT with standard tangential RT. One study compared the results of IMRT in the supine versus the prone position, and one study compared standard treatment with accelerated partial breast IMRT. Three studies reported reduced acute and/or late toxicity using IMRT compared with standard RT. No study reported improved quality of life. Conclusion IMRT seems able to reduce toxicity in selected patients treated with postoperative RT for BC. Further analyses are needed to better define patients who are candidates for this treatment modality. PMID:28293119

  18. Efficacy and adverse reactions of nedaplatin combined with paclitaxel plus intensity-modulated radiotherapy on advanced cervix cancer%奈达铂联合紫杉醇同步放疗治疗中晚期宫颈癌的疗效及不良反应观察

    Institute of Scientific and Technical Information of China (English)

    龙婷婷

    2016-01-01

    Objective To observe the efficacy and toxicity of nedaplatin combined with paclitaxel plus radiotherapy in treatment of ad-vanced cervix cancer.Methods Sixty cases of cervical cancer in IIB to IVA stage were randomized into group A and group B,with 30 cases in each group.The external irradiation dose of radiotherapy was2 Gy per time,5 d/w,with a total dose of 50 Gy;192 Ir high-dose-rate after loading unit was adopted for branchytherapy one week after external radiotherapy,at a dose of 5 Gy per time in A point for 6 times.During radiotherapy group A adopted paclitaxel combined with nedaplatin chemotherapy,while group B adopted paclitaxel com-bined with cisplatin.Treatment in both groups were once a week with a total of 4 ~6 cycles.The clinical effects and adverse reactions were compared.Results The short-term effective rates of group A and group B were 93.3% and 90%,respectively.The difference was not statistically significant (P=0.500).One-,two-,three-year survival rates were 90.0%,72.8%,56.6% in group A and 83. 3%,65.3%,49.0% in group B.There was no statistically significant difference (P=0.413).Median progression-free survival time was 28 months in group A and 22 months in group B with no statistically significant difference (P=0.352).The major adverse reac-tions were bone marrow suppression,gastrointestinal tract reaction.I-IV degree bone marrow suppression occurred in 26 cases of group A and 21 cases of group B with no statistically significant difference (P=0.117).I -IV degree gastrointestinal reaction occurred in 21 cases of group A and 28 cases of group B with statistically significant difference (P=0.020).Conclusions Nedaplatin combined with paclitaxel plus intensity-modulated radiation therapy in patients with locally advanced cervical cancer can obtain higher survival rate,lighter adverse reactions and good patient compliance.%目的:观察紫杉醇结合奈达铂同时予以调强放疗治疗中晚期宫颈癌的治疗效果和不良反应。方

  19. 直肠癌术前容积旋转调强放疗和五野静态调强放疗的剂量学比较%Dosimetric comparison between preoperative volumetric modulated arc therapy and five-field intensity modulated radiotherapy for rectal cancer

    Institute of Scientific and Technical Information of China (English)

    汪琳; 张红雁; 钱立庭; 吴爱东; 方为; 闫冰

    2016-01-01

    目的:比较直肠癌术前患者应用五野静态调强放疗(5F-IMRT)和容积弧形调强放疗( VMAT)两种计划的剂量学差别。方法分别将16例术前行同期放化疗的直肠癌患者进行5F-IMRT和VMAT两种计划设计,应用剂量体积直方图比较分析靶区和危及器官的剂量学差异及治疗参数。结果两种治疗计划均能满足临床剂量要求。5F-IMRT计划的适形指数(CI)为0.88±0.04,VMAT计划的CI为0.90±0.03,两种计划均能很好满足95%等剂量曲线对100%PTV体积的完全覆盖;VMAT 和 IMRT 计划的均匀性指数(HI)分别为1.06±0.01和1.05±0.01,差异无统计学意义(t=1.37,P>0.05)。5F-IMRT和VMAT计划中重要的危及器官如小肠、膀胱和股骨头等的关键剂量评价指标( Dmean、Dmax)及受照射体积的关键评价指标( V20、V30、V40和V50)在两种放疗计划中差异无统计学意义( P >0.05)。VMAT计划组较5F-IMRT计划组机器跳数( MU)平均值减少39%(P=0.000)。结论直肠癌术前放疗中采用VMAT技术可获得等同于5F-IMRT计划的剂量分布,危及器官均能得到较好的保护, VMAT计划MU明显降低,治疗时间明显缩短。%Objective To compare the dosimetric characteristics of volumetric modulated arc therapy( VMAT) and five-field intensity modulated radiotherapy(5F-IMRT) in preoperative radiotherapy for rectal cancer. Methods Six-teen patients with rectal cancer who underwent preoperative chemo-radiotherapy were enrolled in this study. VMAT and 5F-IMRT plans were designed for each patient. The dose distribution in target volumes and organs at risk was e-valuated according to the dose-volume histogram. Results Both plans could meet target dose specifications and nor-mal tissue constraint. The CI was similar between the 5F-IMRT(0. 88 ± 0. 04) and VMAT plans (0. 90 ± 0. 03), which could satisfy 95% of prescribed dose for covered PTV. The HI of the VMAT plan was 1. 06 ± 0. 01 compared to 1. 05 ± 0. 01

  20. Conformal radiotherapy with intensity modulation and integrated boost in the head and neck cancers: experience of the Curie Institute; Radiotherapie conformationnelle avec modulation d'intensite et boost integre des cancers de la tete et du cou: experience de l'institut Curie

    Energy Technology Data Exchange (ETDEWEB)

    Toledano, I.; Serre, A.; Bensadoun, R.J.; Ortholan, C.; Racadot, S.; Calais, G.; Alfonsi, M.; Giraud, P. [Centre Jean-Perrin, 63 - Clermont-Ferrand (France); Graff, P.; Serre, A.; Bensadoun, R.J.; Ortholan, C.; Racadot, S.; Calais, G.; Alfonsi, M.; Giraud, P. [Hopital Europeen Georges-Pompidou, 75 -Paris (France)

    2009-10-15

    The modulated intensity radiotherapy (I.M.R.T.) is used in the treatment of cancers in superior aero digestive tracts to reduce the irradiation of parotids and to reduce the delayed xerostomia. This retrospective study presents the results got on the fourteen first patients according an original technique of I.M.R.T. with integrated boost. It appears that this technique is feasible and allows to reduce the xerostomia rate without modifying the local control rate. To limit the average dose to the parotids under 30 Gy seems reduce the incidence of severe xerostomia. (N.C.)

  1. Intensity modulated short circuit current spectroscopy for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kavasoglu, Nese; Sertap Kavasoglu, A.; Birgi, Ozcan; Oktik, Sener [Mugla University, Faculty of Arts and Sciences, Physics Department, TR-48000 Mugla (Turkey); Mugla University Clean Energy Research and Development Centre, TR-48000 Mugla (Turkey)

    2011-02-15

    Understanding charge separation and transport is momentously important for the rectification of solar cell performance. To probe photo-generated carrier dynamics, we implemented intensity modulated short circuit current spectroscopy (IMSCCS) on porous Si and Cu(In{sub x},Ga{sub 1-x})Se{sub 2} solar cells. In this experiment, the solar cells were lightened with sinusoidally modulated monochromatic light. The photocurrent response of the solar cell as a function of modulation frequency is measured as the optoelectronic transfer function of the system. The optoelectronic transfer function introduces the connection between the modulated light intensity and measured AC current of the solar cell. In this study, interaction of free carriers with the density of states of the porous Si and Cu(In{sub x}, Ga{sub 1-x})Se{sub 2} solar cells was studied on the basis of charge transport time by IMSCCS data. (author)

  2. Dosimetric study of volumetric-modulated arc radiotherapy and fixed field-intensity modulated radiation therapy for cervix ne-oplasms%宫颈癌容积调强与固定野动态调强放疗技术的剂量学比较

    Institute of Scientific and Technical Information of China (English)

    康梅; 权循凤; 李兵兵; 吴莉莉

    2016-01-01

    Objective To compare the dosimetric and organ at risk dose differences of volumetric modulated arc therapy( VMAT) , seven-fixed field intensity-modulated radiation therapy(7-IMRT) and nine-fixed field intensity-modulated radiation therapy(9-IMRT) for cer-vix cancer treated with the definitive whole pelvic radiotherapy. Methods CT images of twelve patients treated with three plans of VMAT,7-IMRT and 9-IMRT techniques were compared in terms of parameters of target,organ at risk( OAR) ,conformity index( HI) and conformity in-dex( CI) . The MUs were scored to measure the expected treatment efficiency. Results All the three plans could achieve the clinically ac-ceptable target coverage. The VMAT plans were the best,while 7-IMRT was the worst in HI and CI of targets. VMAT imposed least doses to the bladder at dose level of 30 Gy,the rectum at the dose level of 30 and 50 Gy. VMAT was the same least on femoral head the volume re-ceived 20 Gy(P<0. 05). Compared with 9-IMRT,7-IMRT showed compared volume of bladder at dose level of 30 Gy,and reduced the vol-ume of femoral head at 20 Gy. The MUs of VMAT plans(757. 69 ± 137. 04) were significantly less than those of 7-IMRT plans(802. 65 ± 183. 85) and 9-IMRT plans(1102. 31 ± 190. 07). Conclusion Three types of plans can achieve the clinical dosimetric demands and protect the OARs. VMAT has the best performance on CI and HI,and decrease the volume of the high-dose area in OARs. VMAT plans have fewer MUs and significantly improve the treatment efficiency regarding total MUs.%目的 比较旋转容积调强技术(VMAT)、固定7野(7-IMRT)及9野动态调强技术(9-IMRT)在宫颈癌根治性放疗中的剂量学参数.方法 选取12例接受根治性放疗的宫颈癌患者,对同一CT图像分别进行二弧VMAT、7野IMRT及9野IMRT计划设计,比较3种放疗计划的靶区剂量和危及器官的剂量学差异、靶区剂量适形度、均匀性以及加速器跳数.结果 VMAT、7-IMRT和9-IMRT计划的靶区剂量均

  3. 直肠癌术前容积调强与固定野调强技术的剂量学比较%Dosimetric Comparison between Preoperative Volumetric Modulated Arc Therapy and Fixed-field Intensity-modulated Radiotherapy for Rectal Cancer

    Institute of Scientific and Technical Information of China (English)

    杨波; 庞廷田; 孙显松; 胡克; 邱杰; 张福泉

    2014-01-01

    Objective To compare the dosimetric characteristics of preoperative volumetric modulated arc therapy ( VMAT) and fixed-field intensity-modulated radiotherapy ( FF-IMRT) for rectal cancer .Methods The CT images of 15 patients with rectal cancer were transferred into Eclipse planning system .FF-IMRT and VMAT plans were optimized on an Eclipse treatment planning system using beam data generated for Varian Trilogy linear accelerator .Same institutional dose-volume constraints for rectal cancer were used in both techniques .Targets and organs at risk were evaluated .Results The target volume coverage could meet the requirement of described dosage in both VMAT plan group and FF-IMRT plan group .Compared with the FF-IMRT plan group , the plan-ning target volume ( PTV) 105% ( PTV105%) coverage, Dmean, and Dmax significantly increased in the VMAT plan group ( P=0.011, P=0.017, and P=0.006, respectively), the radiation conformity index (CI) significantly decreased ( P=0.008 ) , and the homogeneity index showed no significant difference ( P=0.193 ) . Compared with the FF-IMRT plan group , the V50 of the bladder in the VMAT plan group was increased by about 15%( P=0.009 ) , and the Dmax increased by 0.7 Gy ( P=0.003 );the V30 of the small intestine decreased by 10% (P=0.004), and the Dmax was increased by 0.9 Gy (P=0.000); the V10, V30, and V40 of the bone marrow reduced by 2%, 10%, and 10%( P=0.000 , P=0.000 , and P=0.000 ) , and the Dmean re-duced by 1.7 Gy ( P=0.000 );the D5 of the left and right femoral heads reduced by 3.2 Gy and 2.4 Gy ( P=0.000 , P=0.000 ); the V10 , V20 , V30 , and V40 of the body also significantly decreased ( P=0.003 , P=0.000 , P=0.000 , and P=0.004 ) .The VMAT group also had significantly lower number of monitor units ( MU) when compared with the FF-IMRT plan group ( P=0.000 ) .Conclusions In patients with rectal canc-er, preoperative VMAT can achieve equivalent or superior dose distribution compared with the FF -IMRT.In addi-tion, VMAT can

  4. 宫颈癌术后盆腔三维适形与调强放疗剂量学与技术的研究%Technical and dosimetric study of three-dimensional conformal and intensity-modulated pelvic radiotherapy for post-hysterectomy cervical carcinoma

    Institute of Scientific and Technical Information of China (English)

    林原; 周莉均; 徐志勇; 蔡树模; 李子庭; 傅小龙; 章真; 郭小毛; 蒋国梁

    2008-01-01

    Objective To establish the methods of three-dimensional eonformal(3DCRT) and intensity-modulated radiotherapy(IMRT) for whole pelvic irradiation in post-hysterectomy cervical carcinoma, And to optimize the methods for clinical practice. Methods Between 2004 and 2005,10 patients with cervical carcinoma who underwent hysterectomy with high risk of recurrence were selected for this study. The following observations and measurements were used for the study: Set-up errors with supine or prone position were measured to determine appropriate immobilization position. Influence of full and empty bladder on irradiated normal tissue volume was measured. Treatment errors were detected and CTV/PTV were then delineated. 3DCRT and IMRT planning and comparison were applied. Results The set-up error was within 5 mm of three dimensions in prone position and more than 5 mm in supine position, the difference of which was statistically significant. The percentage of irradiated volume of the bladder and bowel was smaller when the bladder was full comparing with empty bladder. In prone position and with full bladder,portal films showed the movement of isocenter in three directions. The total uncertainty was [7.4±1.6]mm. For 95% confidence interval,the margin from CTV to PTV was 1 cm. CIPTV for 3,4,5,and 6 fields 3DCRT was 0.46,O. 67, O. 68, and O. 68, respectively. When beyond 4 fields, the advantage of adding fields was not significant.Four fields planning was feasible for clinical practice. CI for 5,7,9,11 ,and 13 fidds IMRT was 0.75,0.83, 0.84,0.85 ,and 0.85 ,respectively. When beyond 9 fields,the advantage of adding fields was not significant. Nine fields planning was feasible for clinical practice. Conclusions For whole pelvic radiotherapy for post-hysterectomy cervical carcinoma,prone position was better than supine position for immobilization due to smaller set-up errors. The full bladder is recommended during radiotherapy, planning,For clinical practice,4 fields planning is

  5. High dose for prostate irradiation with image guided radiotherapy: Contribution of intensity modulation arc-therapy; Haute dose dans la prostate par radiotherapie guidee par l'image: apport de l'arctherapie avec modulation d'intensite du faisceau

    Energy Technology Data Exchange (ETDEWEB)

    Jouyaux, B.; De Crevoisier, R.; Manens, J.P.; Bellec, J.; Chira, C.; Le Prise, E.; Lafond, C. [Centre Eugene-Marquis, 35 - Rennes (France); De Crevoisier, R.; Manens, J.P.; Cazoulat, G.; Haigron, P.; Lafond, C. [Inserm, U642, 35 - Rennes (France); Universite de Rennes-1, LTSI, 35 - Rennes (France)

    2010-12-15

    Purpose: To compare two Intensity Modulated Radiation Therapy (IMRT) techniques for prostate cancer: the Volumetric Modulated Arc Therapy (VMAT) and the 'Step and Shoot' technique (S and S). Materials and methods: VMAT and S and S plans (RX 18 MV) were created and compared (Wilcoxon test) for 10 patients. The dosimetric goal of both treatments was to deliver 46 Gy to the seminal vesicles and 80 Gy to the prostate, while respecting the dose constrains in the organs at risk of toxicity. For one patient, the two techniques were compared for dose painting and escalation in target volumes defined on MRI and registered thanks to intra-prostatic fiducial. Results: VMAT, compared to S and S, offered: an increase of the PTV2s (prostate) volume receiving 77 to 80 Gy and a decrease of V{sub 82} and V{sub 83}; a decrease of V{sub 4} to V{sub 6}, V{sub 16} to V{sub 23}, and V{sub 69} to V{sub 73} for the rectal wall; a decrease of V{sub 25} for the bladder wall; a decrease of V{sub 21} to V{sub 43} for the femoral heads; a decrease of V{sub 26} to V{sub 44} and V{sub 72} to V{sub 80} but an increase of V{sub 1} to V{sub 21} and V{sub 49} to V{sub 60} for the healthy tissues. The Conformal Index 'COIN' was better with VMAT than S and S (0.60 to 0.66). The delivered MU were significantly reduced with VMAT (8% mean) as well as the delivery time (4 min to 1.5 min). VMAT allowed delivering theoretically 90 Gy in the peripheral zone and 100 Gy in the tumor. Conclusion: In case of prostate irradiation, VMAT shows improvement compared with S and S. In particular, organs at risk are better spared, the delivery time is shortened and the number of delivered UM is decreased. (authors)

  6. Dosiology Comparison of Static Intensity-modulate Radiotherapy and Volumetric Modulated Arc Therapy in the Esophageal Cancer%食管癌静态调强放疗与容积调强放疗计划的剂量学比较

    Institute of Scientific and Technical Information of China (English)

    荆亮; 丁继强

    2015-01-01

    Objective To study the dosiology differences of static intensity-modulate radiotherapy( sIMRT)and volumetric modulated arc therapy( VMAT)in the esophageal cancer. Methods The sIMRT and VMAT regimens were respectively designed for 65 patients with esophageal cancer,and the dosiology parameters were compared be-tween the two groups. Results Compared with the sIMRT,the D99 ,D95 ,Dmean of GTV of the VMAT were lower( P0. 05);for the organs at risk,the V20,V30,mean dose of the VMAT were lower(P0. 05). The ray number of the sIMRT and the VMAT were respec-tively 572. 33 ± 97. 9 and 754. 95 ± 177. 6,compared with the sIMRT,the VMAT was decreased by 24%( P <0. 05). Conclusion Compared with sIMRT,VMAT can improve the target area dose,decrease the radiation time, have the better effect for esophageal cancer.%目的:研究食管癌患者应用静态调强放疗( sIMRT)和容积调强弧形治疗( VMAT)的计划剂量学差异。方法65例食管癌单纯放疗患者分别设计sIMRT、VMAT 2组计划,比较2组的剂量学参数。结果与sIMRT比较,VMAT计划的GTV的D99、D95、Dmean的剂量较低( P<0.05);PTV的99%、95%的覆盖度、最大剂量较高(P<0.05);PTV的105%覆盖度较低(P<0.05);适形指数、不均匀指数相似(P>0.05)。危及器官比较中,VMAT的双肺V20、V30、平均剂量明显低于sIMRT(P<0.05)。脊髓、心脏照射量2组相似(P>0.05)。sIMRT、VMAT的射线数分别为572.33±97.9、754.95±177.6,sIMRT相比于 VMAT降低了24%(P<0.05)。结论与sIMRT相比较,VMAT可以改善靶区剂量,减少照射时间,在食管癌的治疗中可能会有较好的疗效。

  7. Intensity-modulated radiotherapy combined with gemcitabine and cisplatin chemotherapy for local advanced non-small cell lung cancer%调强放疗联合吉西他滨加顺铂治疗局部晚期非小细胞肺癌临床观察

    Institute of Scientific and Technical Information of China (English)

    饶建

    2015-01-01

    目的 观察调强放射治疗联合吉西他滨、顺铂同步化疗治疗局部晚期非小细胞肺癌疗效与安全性.方法 回顾分析2012年1月至2014年6月在我院肿瘤科行调强放疗的45例局部晚期NSCLC患者.给予调强放疗,处方剂量为PTV 50.4 Gy/28次,常规分割,同步GTV推量,PTV-GTV为60 Gy/28次.同步给予化疗,方案为吉西他滨加顺铂,方案为放疗第1d起开始化疗,吉西他滨1.0 g/m2,dl、d8,顺铂25 mg/m2,dl ~3,每21d重复.放疗后再采用该方案化疗4个周期.主要观察指标为总有效率(ORR)、毒副反应.结果 所有患者按计划完成治疗.近期疗效CR 6例,PR 26例,SD 12例,PD 1例.ORR 71.1%.毒副反应主要为恶心、呕吐、骨髓抑制,放射性食管炎,放射性肺炎.结论 调强放疗联合吉西他滨加顺铂同步化疗治疗局部晚期NSCLC近期疗效好,毒副反应可耐受,长期疗效有待进一步随访研究.%Objective To evaluate the clinical efficacy and toxicities of intensity-modulated radiotherapy(IMRT) combined with gemcitabine and cisplatin chemotherapy for patients with locally advanced non-small cell lung cancer(NSCLC).Method Forty five patients with NSCLC who received IMRT from January,2012 to June,2014 in our hospital were retrospectively analyzed.The IMRT plans were designed to deliver 50.4G y/28 f to PTV while delivering 60 Gy/28 f to GTV.Chemotherapy was given from the first day of IMRT,with gemcitabine 1.0 g/m2 on day l to day 8 and cisplatin 25my/m2 on day 1 to day 3.The chemothtrapy was repeated every 21 days,with a total of 4 cycles.The endpoints were overall response rate(ORR) and adverse events.Results All patients completed definitive IMRT and chemotherapy.Complete response(CR),partial response(PR),stable disease(SD),and progressive disease(PD)were observed in 6,26,12,and 1 cases,respectively,with a ORR of 71.1%.The main toxicities were tolerable,which included myelosuppression,nausea,vomiting,acute radiation pneumonia,and acute

  8. 局部晚期鼻咽癌调强放疗联合同期化疗的比较%A Comparative Study of Intensity-Modulated Radiotherapy with Concurrent FP or TP Chemotherapy in Patients with Locally Advanced Nasopharyngeal Carcinoma

    Institute of Scientific and Technical Information of China (English)

    尹宏; 何志刚; 向舫; 李煜; 罗英

    2016-01-01

    Objective:To investigate the differents in patients with locally advanced nasopharyngeal carcinoma who received intensity-modulated radiotherapy( IMRT) with two kind of chemotherapies.Methods:A retrospective analysis was performed on the clinical data of 120 patients with stageⅢorⅣa nasopharyngeal carcinoma who were admitted to our hospital from May 2010 to October 2012.60 received IMRT with 5-fluorouracil plus nedaplatin ( FP) chemotherapy,and 60 received IMRT with taxol plus nedaplatin (TP) chemotherapy.The Kaplan-Meier method wasused to calculate the survival rates,and the log-rank test was used to analyze the survival difference;the chisquare test was used to compare the acute toxicities in the two groups.Results:The follow-up rate was 100.00%.The 1、2-yearssurvival rate in the IMRT/FP group were 100.00%and 95.0%respectively, versus 100%and 91.7%in the IMRT/TP group.No significant difference was found between the two groups (P>0.05).The incidence rates of leukopenia ( grade≥3 ) , thrombocytopenia ( grade≥3 ) in the IMRT/FP group were 28.3% and 15.0%respectively, versus 65.0%and 23.3%in the IMRT/TP group ( P<0.05) .Conclusion:Compares with IMRT with concurrent FP chemotherapy, IMRT with concurrent TP chemotherapy does not lead to significantly better in survival rate, but have more acute toxicities.%目的:比较局部晚期鼻咽癌行调强放疗( IMRT)同期FP、TP方案化疗的差异。方法:将我院2010年5月至2012年10月收治的120例Ⅲ期、Ⅳa期局部晚期鼻咽癌患者分为2组,观察组行IMRT同期FP化疗,对照组行IMRT同期TP化疗。比较2组的疗效和不良反应。结果:随访率100%,观察组1年生存率为100畅00%,2年生存率为95畅0%;对照组1年生存率为100畅00%,2年生存率为91畅7%,2组比较无显著性差异( P>0畅05)。≥3级白细胞减少、血小板减少发生率观察组分别为28畅3%和15畅0%,对照组分别为65畅0%和23畅3%,2

  9. Phase Ⅰ / Ⅱ clinical trial of docetaxel, cisplatin, and fluorouracil induction chemotherapy followed by intensity-modulated radiotherapy and concomitant chemotherapy in locally advanced nasopharyngeal carcinoma%局部晚期鼻咽癌调强放疗同期化疗前TPF诱导化疗Ⅰ和Ⅱ期临床研究

    Institute of Scientific and Technical Information of China (English)

    张群; 何妨; 康德华; 王振宇; 文碧秀; 罗伟

    2013-01-01

    Objective To investigate the maximum-tolerated dose (MTD) of cisplatin in docetaxel,cisplatin,and fluorouracil (TPF) induction chemotherapy followed by intensity-modulated radiotherapy (IMRT) and concomitant chemotherapy as well as the safety and short-term efficacy of TPF induction chemotherapy in the treatment of locally advanced nasopharyngeal carcinoma (NPC).Methods Thirtythree patients with locally advanced NPC were enrolled in this trial.The MTD of cisplatin was determined by dose escalation study,and the short-term efficacy and toxicities were evaluated.Results When the doses of docetaxel and fluorouracil were 60 mg/m2 d1 and 550 mg/m2 d1-5,respectively,the MTD of cisplatin was 65 mg/m2 d1.In this regimen (repeated every 3 weeks),grade 3-4 toxicities included neutropenia (67%),febrile neutropenia (9%),diarrhea (21%),and oral mucositis (6%).Except those who experienced dose-limited toxicity,other patients completed the whole treatment schedule.After TPF induction chemotherapy,the overall response rate was 97%,and the complete response rate was 21%.Conclusions In the endemic areas of NPC,induction chemotherapy with docetaxel (60 mg/m2 d1),cisplatin (65 mg/m2 d1),and fluorouracil (550 mg/m2 d1-5),which is repeated every 3 weeks,is proved safe and effective for Asian patients with locally advanced NPC.%目的 探讨局部晚期鼻咽癌调强放疗同期化疗前多西泰索加顺铂加氟尿嘧啶方案诱导化疗中顺铂最大耐受剂量(MTD)及方案安全性、有效性.方法 选取33例局部晚期鼻咽癌患者,通过剂量递增试验确立顺铂MTD并评价临床疗效及不良反应.结果 多西泰索60 mg/m2第1天、氟尿嘧啶550 mg/m2第1~5天剂量下顺铂MTD为65 mg/m2第1天,每3周重复下3、4级不良反应发生率分别为中性粒细胞降低67%,粒细胞缺乏性发热9%,腹泻21%,口腔黏膜炎6%.除剂量限制性毒性患者外,其余均完成了治疗.诱导化疗后有效率为97%,其中完

  10. Variation in radiotherapy target volume definition, dose to organs at risk and clinical target volumes using anatomic (computed tomography) versus combined anatomic and molecular imaging (positron emission tomography/computed tomography): intensity-modulated radiotherapy delivered using a tomotherapy Hi Art machine: final results of the VortigERN study.

    Science.gov (United States)

    Chatterjee, S; Frew, J; Mott, J; McCallum, H; Stevenson, P; Maxwell, R; Wilsdon, J; Kelly, C G

    2012-12-01

    Contrast-enhanced computed tomography (CECT) is the current standard for delineating tumours of the head and neck for radiotherapy. Although metabolic imaging with positron emission tomography (PET) has been used in recent years, the studies were non-confirmatory in establishing its routine role in radiotherapy planning in the modern era. This study explored the difference in gross tumour volume and clinical target volume definitions for the primary and nodal volumes when FDG PET/CT was used as compared with CECT in oropharyngeal cancer cases. Twenty patients with oropharyngeal cancers had a PET/CT scan in the treatment position after consent. Target volumes were defined on CECT scans by a consultant clinical oncologist who was blind to the PET scans. After obtaining inputs from a radiologist, another set of target volumes were outlined on the PET/CT data set. The gross and clinical target volumes as defined on the two data sets were then analysed. The hypothesis of more accurate target delineation, preventing geographical miss and comparative overlap volumes between CECT and PET/CT, was explored. The study also analysed the volumes of intersection and analysed whether there was any TNM stage migration when PET/CT was used as compared with CECT for planning. In 17 of 20 patients, the TNM stage was not altered when adding FDG PET information to CT. PET information prevented geographical miss in two patients and identified distant metastases in one case. PET/CT gross tumour volumes were smaller than CECT volumes (mean ± standard deviation: 25.16 cm(3) ± 35.8 versus 36.56 cm(3) ± 44.14; P 0.86) were not statistically different. Similarity and discordance coefficients were calculated and are reported. PET/CT as compared with CECT could provide more clinically relevant information and prevent geographical miss when used for radiotherapy planning for advanced oropharyngeal tumours. Also, PET/CT provided a smaller better-defined target volume when compared with CECT

  11. MO-G-BRF-06: Radiotherapy and Prompt Oxygen Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Kissick, M; Campos, D; Adamson, E; Niles, D; Torres, A; L, Che Fru; Kimple, R; Fain, S; Kogel, A van der [University of Wisconsin - Madison, Madison, WI (United States); Jacques, S [Oregon Health ' Science University, Portland, OR (United States)

    2014-06-15

    Purpose: Adaptive radiotherapy requires a knowledge of the changing local tumor oxygen concentrations for times on the order of the treatment time, a time scale far shorter than cell death and proliferation. This knowledge will be needed to guide hypofractionated radiotherapy. Methods: A diffuse optical probe system was developed to spatially average over the whole interior of athymic Sprague Dawley nude mouse xenografts of human head and neck cancers. The blood volume and hemoglobin saturation was measured in real time. The quantities were measured with spectral fitting before and after 10 Gy of radiation is applied. An MRI BOLD scan is acquired before and after 10 Gy that measures regional changes in R2* which is inversely proportional to oxygen availability. Simulations were performed to fit the blood oxygen dynamics and infer changes in hypoxia within the tumor. Results: The optical probe measured nearly constant blood volume and a significant drop in hemoglobin saturation of about 30% after 10 Gy over the time scale of less than 30 minutes. The averaged R2* within the tumor volume increased by 15% after the 10 Gy dose, which is consistent with the optical results. The simulations and experiments support likely dynamic metabolic changes and/or fast vasoconstrictive signals are occurring that change the oxygen concentrations significantly, but not cell death or proliferation. Conclusion: Significant oxygen changes were observed to occur within 30 minutes, coinciding with the treatment time scale. This dynamic is very important for patient specific adaptive therapy. For hypofractionated therapy, the local instantaneous oxygen content is likely the most important variable to control. The invention of a bedside device for the purpose of measuring the instantaneous response to large radiation doses would be an important step to future improvements in outcome.

  12. 直肠癌术前五野静态调强和容积弧形调强放疗剂量学的比较研究%Dosimetric comparison between preoperative five-field intensity modulated radiotherapy and volumetric modulated arc therapy in the treatment of rectum cancer

    Institute of Scientific and Technical Information of China (English)

    叶序卷; 高远红; 陈利; 杜乐辉; 张广顺; 贾钰铭; 雷开键; 刘孟忠

    2012-01-01

    目的 探讨直肠癌术前五野静态调强(5 F-IMRT)和容积弧形调强(VMAT)放疗计划的剂量学特点.方法 应用CMS monaco治疗计划系统分别对23例术前同期放化疗的直肠癌患者行5F-IMRT和VMAT放疗计划设计,比较两种放疗技术的靶区剂量分布特点以及小肠、膀胱、双侧股骨头等正常组织的受照射剂量及体积.结果 5F-IMRT计划的适形指数(CI)为0.810±0.043,VMAT计划的CI为0.822±0.062,两者均能很好满足95%等剂量曲线对100% PTV体积的完全覆盖;5F-IMRT计划中GTV、CTV和PTV的均匀指数(HI)分别为1.052±0.019、1.063±0.016、1.075±0.020,VMAT计划分别为1.037±0.008、1.047 ±0.008、1.072±0.018,差异均无统计学意义.5F-IMRT和 VMAT计划中重耍的危及器官如小肠、膀胱和股骨头等的关键剂量评价指标(D5、Dmin、Dmean和Dmax)差异均无统计学意义(P>0.05).小肠、膀胱和股骨头等受照射体积的关键评价指标(V20、V30、V40和V50)在两种放疗计划中差异均无统计学意义(P>0.05).结论 5F-IMRT和VMAT计划靶区的剂量分布均较理想,对小肠、膀胱、双侧股骨头等正常组织均有很好的保护作用.%Objective To investigate the dosimetric comparison between prenperalive live-field intensity modulated radiotherapy (5F-IMRT) and volumetric modulated arc therapy ( VMAT) in the. rectum cancer patients with concurrent chemotherapy and radiotherapy. Methods With the application of CMS monaco syslems( V2. 0,Sweden) , 5F-IMRT and VMAT plans were simulated in 23 rectum cancer patients with preoperative concurrent chemoradlotherapy. The dose characteristic of target volume was evaluated and the dose-volume relationship of small bowel, bladder and bilateral femoral head was compared. Results The CI was similar between the 5F-IMRT(0. 810 ±0. 043) and VMAT plans(0. 822 ±0. 062) , which could satisfy 95% of prescribed dose for covered PTV. The HI of the prescribed dose to GTV( 1. 052 ±0. 019 vs. 1

  13. To investigate the dose changes of parotid glands between before and after intensity-modulated radiotherapy for nasopharyngeal carcinoma%鼻咽癌调强放射治疗前后腮腺照射剂量变化研究

    Institute of Scientific and Technical Information of China (English)

    张瑜; 费召东; 林兴福

    2015-01-01

    目的:研究调强放射治疗前后腮腺的实际照射剂量变化。方法:入组18例进行调强放射治疗的鼻咽癌患者。治疗前后各扫描一组CT图像。临床医生在这两组图像中分别勾画出腮腺及外轮廓。通过图像配准技术,把治疗结束时的腮腺及外轮廓映射至治疗前的计划CT图像上。经过外轮廓进行修正后,使用治疗前计划计算出治疗后剂量。分析腮腺治疗前后在体积和空间位置变化时引起的剂量学的变化。结果:左右腮腺治疗前后体积, D50, V42数值均有较大的变化。前后配对t检验结果,左右体积为t=7.29(P<0.01), t=7.65(P<0.01);左右D50为t =4.09(P<0.01), t=4.54(P<0.01);左右V42为t=4.95(P<0.01), t=4.36(P<0.01)。均有统计学意义。结论:放射治疗前后腮腺体积与空间位置变化的条件下,腮腺的剂量与治疗前的计划剂量有很大差异。而且剂量基本呈现增大的趋势,需要正确的评估其剂量,才能对于腮腺的功能给出合理的估计。%Objective: To investigate the dose changes of parotid glands between before and after intensity-modulated radiotherapy ( IMRT) for nasopharyngeal carcinoma ( NPC) .Methods:18 patients with NPC were treated by IMRT.Computed tomography ( CT) was acquired before and after treatment.The each slide of parotid glands was contoured independently by physician.Then the after treatment contour of parotid glands and body external contour mapped onto the before treatment CT image series by Pinnacle planning system.The dose of parotid glands of after treatment was computed using the original plan with body external contour correction and compared to the dose of original plan.Results:There were significant in statistics to parotid glands volume, dose of 50% volume of parotid glands, percent volume of parotid glands at 42Gy.Left and right volume of parotid glands were t =7.29 (P<0.01); t

  14. Toxicities of intensity-modulated radiotherapy with or without pelvic nodal irradiation in patients with localized prostate cancer:a comparative study%前列腺癌局部调强放疗是否同步盆腔照射不良反应比较

    Institute of Scientific and Technical Information of China (English)

    刘跃平; 李晔雄; 王维虎; 金晶; 房辉; 王淑莲; 宋永文; 任骅; 刘新帆

    2013-01-01

    Objective To analyze the acute and late intestinal and genitourinary toxicities of intensity-modulated radiotherapy (IMRT) with or without pelvic nodal irradiation in patients with localized prostate cancer.Methods Eighty-three patients with pelvic-confined prostate cancer,who received radical IMRT between February 2009 and March 2012,were included in the study.Of them,38 low-and mediumrisk patients received hypofractionated IMRT (67.5 Gy) to the prostate (and seminal vesicles),and 45 high-risk patients or patients who had an assessed risk of pelvic lymph node metastasis above 15% received hypofractionated IMRT (67.5 Gy) to the prostate and seminal vesicles as well as prophylactic irradiation (50 Gy) to the pelvic lymph nodes.The gastrointestinal and genitourinary toxieities were evaluated during and after radiotherapy.Acute toxicities were graded according to common terminology criteria for adverse events,version 3.0,while late toxicities were graded according to the toxicity criteria of the radiation therapy oncology group.Results Of the patients receiving pelvic nodal irradiation,27% and 0% experienced grade 2 and 3 acute gastrointestinal toxicities,versus 5% and 3% of those not receiving pelvic nodal irradiation (P =0.025) ;11% and 9% of the patients receiving pelvic nodal irradiation experienced grade 2 and 3 late gastrointestinal toxicities,versus 29% and 3% of those not receiving pelvic nodal irradiation (P =0.170).Of the patients receiving pelvic nodal irradiation,13% and 0% experienced grade 2 and 3 acute genitourinary toxicities,versus 16% and 3% of those not receiving pelvic nodal irradiation (P =0.368) ;9% and 2% of the patients receiving pelvic nodal irradiation experienced grade 2 and 3 late genitourinary toxicities,versus 24% and 3% of those not receiving pelvic nodal irradiation (P =0.066).Conclusions Pelvic nodal irradiation during IMRT increases the incidence of acute gastrointestinal toxicity in patients with

  15. 不同调强技术在宫颈癌骨髓保护根治性放疗中的应用%Various Techniques of Bone Marrow-Sparing Intensity Modulated Radiation Therapy in Cervical Cancer Treated with Definitive Radiotherapy

    Institute of Scientific and Technical Information of China (English)

    林柏翰; 吴丽丽; 张基永

    2015-01-01

    目的:分析比较固定野调强技术和不同弧数的旋转容积调强在宫颈癌骨髓保护根治性全盆腔放射治疗的剂量学特点,寻找更优的治疗方案。方法:选取在汕头大学医学院附属肿瘤医院接受根治性放疗的ⅡA~ⅢB期宫颈癌患者9例,针对每例患者分别设计九野固定野调强(FF-IMRT)计划、双弧、三弧和四弧旋转容积调强(2A-VMAT、3A-VMAT、4VMAT)计划,比较四者靶区、骨盆骨髓,其他危及器官的剂量学差异和加速器跳数和照射时间。结果:IMRT、2A-VMAT、3A-VMAT和4A-VMAT四组计划均具有良好的靶区覆盖率,靶区适形度和均匀性以及骨盆骨髓受照剂量和受照体积(V10,V20,V40)无差异。三组VMAT计划在危及器官的保护上无差异。VMAT计划的小肠均略低于FF-IMRT计划(P<0.008),在直肠的保护上,FF-IMRT计划略优于3弧VMAT计划(P<0.008)。IMRT、2A-VMAT、3A-VMAT和4A-VMAT计划的加速器跳数分别为(1850.3±227.8)MU、(848.4±58.8)MU、(835.0±76.2)MU和(910.8±43.3)MU,照射时间分别为(353.2±25.1)s、(136.2±3.6)s、(211.2±3.5)s和(286.2±3.4)s。各组的加速器跳数和照射时间比较差异有统计学意义,调强计划的跳数和照射时间最多,两弧VMAT最少。结论:综合考虑各种物理和生物因素,在宫颈癌骨髓保护根治性放疗计划中,双弧VMAT技术照射为最优选择。%Objective: To compare static intensity-modulated radiation therapy (IMRT) technique with various arcs of volumetric-modulated arc radiation therapy (VMAT) techniques in patients with cervical cancer treated with definitive bone morrow-sparing whole pelvic radiotherapy, and to explore a better treatment management.Method: 9 CT image sets of staged ⅡA-ⅢB cervical cancer patients, treated in Cancer Hospital of Shantou University Medical College, were included. Nine fixed-field IMRT (FF-IMRT) plans and two

  16. Prioritized efficiency optimization for intensity modulated proton therapy

    Science.gov (United States)

    Müller, Birgit S.; Wilkens, Jan J.

    2016-12-01

    A high dosimetric quality and short treatment time are major goals in radiotherapy planning. Intensity modulated proton therapy (IMPT) plans obtain dose distributions of great conformity but often result in long delivery times which are typically not incorporated into the optimization process. We present an algorithm to optimize delivery efficiency of IMPT plans while maintaining plan quality, and study the potential trade-offs of these interdependent objectives. The algorithm is based on prioritized optimization, a stepwise approach to implemented objectives. First the quality of the plan is optimized. The second step of the prioritized efficiency optimization (PrEfOpt) routine offers four alternatives for reducing delivery time: minimization of the total spot weight sum (A), maximization of the lowest spot intensity of each energy layer (B), elimination of low-weighted spots (C) or energy layers (D). The trade-off between dosimetric quality (step I) and treatment time (step II) is controlled during the optimization by option-dependent parameters. PrEfOpt was applied to a clinical patient case, and plans for different trade-offs were calculated. Delivery times were simulated for two virtual facilities with constant and variable proton current, i.e. independent and dependent on the optimized spot weight distributions. Delivery times decreased without major degradation of plan quality; absolute time reductions varied with the applied method and facility type. Minimizing the total spot weight sum (A) reduced times by 28% for a similar plan quality at a constant current (changes of minimum dose in the target  process can yield reduced delivery times with similar plan qualities. A potential clinical application of PrEfOpt is the generation of multiple plans with different trade-offs for a multicriteria optimization setting. Then, the planner can select the preferred compromise between treatment time and quality for each individual patient.

  17. Optimization of verification pretreatment of plans of radiotherapy treatment with the technique of arcoterapia with RapidArc VMAT intensity-modulated; Optimizacion de la verificacion pretratamiento de los planes de tratamiento radioterapico con la tecnica de arcoterapia con intensidad modulada RapidArc VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Serna Berna, A.; Puchades Puchades, V.; Mata Cologro, F.; Ramos Amores, D.

    2013-07-01

    The pretreatment verification of plans arcoterapia intensity modulated (VMAT) increases the workload on the services of radio physics. These checks focus with two objectives: First, check the dose calculation system for treatment planning; and second verify that the accelerator is able to administer treatment as has been planned. There are different commercial solutions to facilitate this procedure. The purpose of this paper is to compare the efficiency of four sets of independent verification to establish an optimal protocol. (Author)

  18. Comparison of dosimetry achieved using volumetric modulated arc therapy or static intensity-modulated radiotherapy to