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Phillip J Taddei - One of the best experts on this subject based on the ideXlab platform.
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inter institutional comparison of personalized risk assessments for second malignant neoplasms for a 13 year old girl receiving Proton versus photon craniospinal irradiation
Cancers, 2015Co-Authors: Rui Zhang, Phillip J Taddei, Anita Mahajan, Nabil Khater, Fady B Geara, Wassim Jalbout, A PerezandujarAbstract:Children receiving radiotherapy face the probability of a subsequent malignant neoplasm (SMN). In some cases, the predicted SMN risk can be reduced by Proton therapy. The purpose of this study was to apply the most comprehensive dose assessment methods to estimate the reduction in SMN risk after Proton therapy vs. photon therapy for a 13-year-old girl requiring craniospinal irradiation (CSI). We reconstructed the equivalent dose throughout the patient’s body from therapeutic and stray radiation and applied SMN incidence and mortality risk models for each modality. Excluding skin cancer, the risk of incidence after Proton CSI was a third of that of photon CSI. The predicted absolute SMN risks were high. For photon CSI, the SMN incidence rates greater than 10% were for thyroid, non-melanoma skin, lung, colon, stomach, and other solid cancers, and for Proton CSI they were non-melanoma skin, lung, and other solid cancers. In each setting, lung cancer accounted for half the risk of mortality. In conclusion, the predicted SMN risk for a 13-year-old girl undergoing Proton CSI was reduced vs. photon CSI. This study demonstrates the feasibility of inter-institutional whole-body dose and risk assessments and also serves as a model for including risk estimation in personalized cancer care.
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a comparative study on the risks of radiogenic second cancers and cardiac mortality in a set of pediatric medulloblastoma patients treated with photon or Proton craniospinal irradiation
Radiotherapy and Oncology, 2014Co-Authors: Rui Zhang, R Howell, Phillip J Taddei, A GiebelerAbstract:Abstract Purpose To compare the risks of radiogenic second cancers and cardiac mortality in 17 pediatric medulloblastoma patients treated with passively scattered Proton or field-in-field photon craniospinal irradiation (CSI). Material/methods Standard of care photon or Proton CSI treatment plans were created for all 17 patients in a commercial treatment planning system (TPS) (Eclipse version 8.9; Varian Medical Systems, Palo Alto, CA) and prescription dose was 23.4 or 23.4Gy (RBE) to the age specific target volume at 1.8Gy/fraction. The therapeutic doses from Proton and photon CSI plans were estimated from TPS. Stray radiation doses were determined from Monte Carlo simulations for Proton CSI and from measurements and TPS for photon CSI. The Biological Effects of Ionization Radiation VII report and a linear model based on childhood cancer survivor data were used for risk predictions of second cancer and cardiac mortality, respectively. Results The ratios of lifetime attributable risk ( RLAR s) (Proton/photon) ranged from 0.10 to 0.22 for second cancer incidence and ranged from 0.20 to 0.53 for second cancer mortality, respectively. The ratio of relative risk ( RRR ) (Proton/photon) of cardiac mortality ranged from 0.12 to 0.24. The RLAR s of both cancer incidence and mortality decreased with patient's age at exposure ( e ), while the RRR s of cardiac mortality increased with e . Girls had a significantly higher RLAR of cancer mortality than boys. Conclusion Passively scattered Proton CSI provides superior predicted outcomes by conferring lower predicted risks of second cancer and cardiac mortality than field-in-field photon CSI for all medulloblastoma patients in a large clinically representative sample in the United States, but the magnitude of superiority depends strongly on the patients' anatomical development status.
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comparison of risk of radiogenic second cancer following photon and Proton craniospinal irradiation for a pediatric medulloblastoma patient
Physics in Medicine and Biology, 2013Co-Authors: Rui Zhang, Phillip J Taddei, A Giebeler, Rebecca Maureen Howell, Anita Mahajan, Wayne D NewhauserAbstract:Pediatric patients who received radiation therapy are at risk of developing side effects such as radiogenic second cancer. We compared Proton and photon therapies in terms of the predicted risk of second cancers for a 4 year old medulloblastoma patient receiving craniospinal irradiation (CSI). Two CSI treatment plans with 23.4 Gy or Gy (RBE) prescribed dose were computed: a three-field 6 MV photon therapy plan and a four-field Proton therapy plan. The primary doses for both plans were determined using a commercial treatment planning system. Stray radiation doses for Proton therapy were determined from Monte Carlo simulations, and stray radiation doses for photon therapy were determined from measured data. Dose–risk models based on the Biological Effects of Ionization Radiation VII report were used to estimate the risk of second cancer in eight tissues/organs. Baseline predictions of the relative risk for each organ were always less for Proton CSI than for photon CSI at all attained ages. The total lifetime attributable risk of the incidence of second cancer considered after Proton CSI was much lower than that after photon CSI, and the ratio of lifetime risk was 0.18. Uncertainty analysis revealed that the qualitative findings of this study were insensitive to any plausible changes of dose–risk models and mean radiation weighting factor for neutrons. Proton therapy confers lower predicted risk of second cancer than photon therapy for the pediatric medulloblastoma patient.
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the risk of developing a second cancer after receiving craniospinal Proton irradiation
Physics in Medicine and Biology, 2009Co-Authors: Phillip J Taddei, Anita Mahajan, Wayne D Newhauser, Jonas D Fontenot, David G Kornguth, Marilyn Stovall, Y Zheng, Dragan MirkovicAbstract:The purpose of this work was to compare the risk of developing a second cancer after craniospinal irradiation using photon versus Proton radiotherapy by means of simulation studies designed to account for the effects of neutron exposures. Craniospinal irradiation of a male phantom was calculated for passively-scattered and scanned-beam Proton treatment units. Organ doses were estimated from treatment plans; for the Proton treatments, the amount of stray radiation was calculated separately using the Monte Carlo method. The organ doses were converted to risk of cancer incidence using a standard formalism developed for radiation protection purposes. The total lifetime risk of second cancer due exclusively to stray radiation was 1.5% for the passively scattered treatment versus 0.8% for the scanned Proton beam treatment. Taking into account the therapeutic and stray radiation fields, the risk of second cancer from intensity-modulated radiation therapy and conventional radiotherapy photon treatments were 7 and 12 times higher than the risk associated with scanned-beam Proton therapy, respectively, and 6 and 11 times higher than with passively scattered Proton therapy, respectively. Simulations revealed that both passively scattered and scanned-beam Proton therapies confer significantly lower risks of second cancers than 6 MV conventional and intensity-modulated photon therapies.
M Vanderhaeghen - One of the best experts on this subject based on the ideXlab platform.
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the two photon exchange contribution to elastic electron nucleon scattering at large momentum transfer
Physical Review D, 2005Co-Authors: Andrei Afanasev, Stanley J Brodsky, Carl E Carlson, Yuchun Chen, M VanderhaeghenAbstract:We estimate the two-photon exchange contribution to elastic electron-Proton scattering at large momentum transfer by using a quark-parton representation of virtual Compton scattering. We thus can relate the two-photon exchange amplitude to the generalized parton distributions which also enter in other wide angle scattering processes. We find that the interference of one- and two-photon exchange contribution is able to substantially resolve the difference between electric form factor measurements from Rosenbluth and polarization transfer experiments. Two-photon exchange has additional consequences which could be experimentally observed, including nonzero polarization effects and a positron-Proton/electron-Proton scattering asymmetry. The predicted Rosenbluth plot is no longer precisely linear; it acquires a measurable curvature, particularly at large laboratory angle.
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partonic calculation of the two photon exchange contribution to elastic electron Proton scattering at large momentum transfer
Physical Review Letters, 2004Co-Authors: Yuchun Chen, Andrei Afanasev, Stanley J Brodsky, Carl E Carlson, M VanderhaeghenAbstract:We estimate the two-photon exchange contribution to elastic electron-Proton scattering at large momentum transfer through the scattering off a parton in the Proton. We relate the two-photon exchange amplitude to the generalized parton distributions which appear in hard exclusive processes. We find that when taking the polarization transfer determinations of the form factors as input, adding in the 2-photon correction does reproduce the Rosenbluth cross sections.
Rui Zhang - One of the best experts on this subject based on the ideXlab platform.
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inter institutional comparison of personalized risk assessments for second malignant neoplasms for a 13 year old girl receiving Proton versus photon craniospinal irradiation
Cancers, 2015Co-Authors: Rui Zhang, Phillip J Taddei, Anita Mahajan, Nabil Khater, Fady B Geara, Wassim Jalbout, A PerezandujarAbstract:Children receiving radiotherapy face the probability of a subsequent malignant neoplasm (SMN). In some cases, the predicted SMN risk can be reduced by Proton therapy. The purpose of this study was to apply the most comprehensive dose assessment methods to estimate the reduction in SMN risk after Proton therapy vs. photon therapy for a 13-year-old girl requiring craniospinal irradiation (CSI). We reconstructed the equivalent dose throughout the patient’s body from therapeutic and stray radiation and applied SMN incidence and mortality risk models for each modality. Excluding skin cancer, the risk of incidence after Proton CSI was a third of that of photon CSI. The predicted absolute SMN risks were high. For photon CSI, the SMN incidence rates greater than 10% were for thyroid, non-melanoma skin, lung, colon, stomach, and other solid cancers, and for Proton CSI they were non-melanoma skin, lung, and other solid cancers. In each setting, lung cancer accounted for half the risk of mortality. In conclusion, the predicted SMN risk for a 13-year-old girl undergoing Proton CSI was reduced vs. photon CSI. This study demonstrates the feasibility of inter-institutional whole-body dose and risk assessments and also serves as a model for including risk estimation in personalized cancer care.
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a comparative study on the risks of radiogenic second cancers and cardiac mortality in a set of pediatric medulloblastoma patients treated with photon or Proton craniospinal irradiation
Radiotherapy and Oncology, 2014Co-Authors: Rui Zhang, R Howell, Phillip J Taddei, A GiebelerAbstract:Abstract Purpose To compare the risks of radiogenic second cancers and cardiac mortality in 17 pediatric medulloblastoma patients treated with passively scattered Proton or field-in-field photon craniospinal irradiation (CSI). Material/methods Standard of care photon or Proton CSI treatment plans were created for all 17 patients in a commercial treatment planning system (TPS) (Eclipse version 8.9; Varian Medical Systems, Palo Alto, CA) and prescription dose was 23.4 or 23.4Gy (RBE) to the age specific target volume at 1.8Gy/fraction. The therapeutic doses from Proton and photon CSI plans were estimated from TPS. Stray radiation doses were determined from Monte Carlo simulations for Proton CSI and from measurements and TPS for photon CSI. The Biological Effects of Ionization Radiation VII report and a linear model based on childhood cancer survivor data were used for risk predictions of second cancer and cardiac mortality, respectively. Results The ratios of lifetime attributable risk ( RLAR s) (Proton/photon) ranged from 0.10 to 0.22 for second cancer incidence and ranged from 0.20 to 0.53 for second cancer mortality, respectively. The ratio of relative risk ( RRR ) (Proton/photon) of cardiac mortality ranged from 0.12 to 0.24. The RLAR s of both cancer incidence and mortality decreased with patient's age at exposure ( e ), while the RRR s of cardiac mortality increased with e . Girls had a significantly higher RLAR of cancer mortality than boys. Conclusion Passively scattered Proton CSI provides superior predicted outcomes by conferring lower predicted risks of second cancer and cardiac mortality than field-in-field photon CSI for all medulloblastoma patients in a large clinically representative sample in the United States, but the magnitude of superiority depends strongly on the patients' anatomical development status.
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comparison of risk of radiogenic second cancer following photon and Proton craniospinal irradiation for a pediatric medulloblastoma patient
Physics in Medicine and Biology, 2013Co-Authors: Rui Zhang, Phillip J Taddei, A Giebeler, Rebecca Maureen Howell, Anita Mahajan, Wayne D NewhauserAbstract:Pediatric patients who received radiation therapy are at risk of developing side effects such as radiogenic second cancer. We compared Proton and photon therapies in terms of the predicted risk of second cancers for a 4 year old medulloblastoma patient receiving craniospinal irradiation (CSI). Two CSI treatment plans with 23.4 Gy or Gy (RBE) prescribed dose were computed: a three-field 6 MV photon therapy plan and a four-field Proton therapy plan. The primary doses for both plans were determined using a commercial treatment planning system. Stray radiation doses for Proton therapy were determined from Monte Carlo simulations, and stray radiation doses for photon therapy were determined from measured data. Dose–risk models based on the Biological Effects of Ionization Radiation VII report were used to estimate the risk of second cancer in eight tissues/organs. Baseline predictions of the relative risk for each organ were always less for Proton CSI than for photon CSI at all attained ages. The total lifetime attributable risk of the incidence of second cancer considered after Proton CSI was much lower than that after photon CSI, and the ratio of lifetime risk was 0.18. Uncertainty analysis revealed that the qualitative findings of this study were insensitive to any plausible changes of dose–risk models and mean radiation weighting factor for neutrons. Proton therapy confers lower predicted risk of second cancer than photon therapy for the pediatric medulloblastoma patient.
A Giebeler - One of the best experts on this subject based on the ideXlab platform.
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a comparative study on the risks of radiogenic second cancers and cardiac mortality in a set of pediatric medulloblastoma patients treated with photon or Proton craniospinal irradiation
Radiotherapy and Oncology, 2014Co-Authors: Rui Zhang, R Howell, Phillip J Taddei, A GiebelerAbstract:Abstract Purpose To compare the risks of radiogenic second cancers and cardiac mortality in 17 pediatric medulloblastoma patients treated with passively scattered Proton or field-in-field photon craniospinal irradiation (CSI). Material/methods Standard of care photon or Proton CSI treatment plans were created for all 17 patients in a commercial treatment planning system (TPS) (Eclipse version 8.9; Varian Medical Systems, Palo Alto, CA) and prescription dose was 23.4 or 23.4Gy (RBE) to the age specific target volume at 1.8Gy/fraction. The therapeutic doses from Proton and photon CSI plans were estimated from TPS. Stray radiation doses were determined from Monte Carlo simulations for Proton CSI and from measurements and TPS for photon CSI. The Biological Effects of Ionization Radiation VII report and a linear model based on childhood cancer survivor data were used for risk predictions of second cancer and cardiac mortality, respectively. Results The ratios of lifetime attributable risk ( RLAR s) (Proton/photon) ranged from 0.10 to 0.22 for second cancer incidence and ranged from 0.20 to 0.53 for second cancer mortality, respectively. The ratio of relative risk ( RRR ) (Proton/photon) of cardiac mortality ranged from 0.12 to 0.24. The RLAR s of both cancer incidence and mortality decreased with patient's age at exposure ( e ), while the RRR s of cardiac mortality increased with e . Girls had a significantly higher RLAR of cancer mortality than boys. Conclusion Passively scattered Proton CSI provides superior predicted outcomes by conferring lower predicted risks of second cancer and cardiac mortality than field-in-field photon CSI for all medulloblastoma patients in a large clinically representative sample in the United States, but the magnitude of superiority depends strongly on the patients' anatomical development status.
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comparison of risk of radiogenic second cancer following photon and Proton craniospinal irradiation for a pediatric medulloblastoma patient
Physics in Medicine and Biology, 2013Co-Authors: Rui Zhang, Phillip J Taddei, A Giebeler, Rebecca Maureen Howell, Anita Mahajan, Wayne D NewhauserAbstract:Pediatric patients who received radiation therapy are at risk of developing side effects such as radiogenic second cancer. We compared Proton and photon therapies in terms of the predicted risk of second cancers for a 4 year old medulloblastoma patient receiving craniospinal irradiation (CSI). Two CSI treatment plans with 23.4 Gy or Gy (RBE) prescribed dose were computed: a three-field 6 MV photon therapy plan and a four-field Proton therapy plan. The primary doses for both plans were determined using a commercial treatment planning system. Stray radiation doses for Proton therapy were determined from Monte Carlo simulations, and stray radiation doses for photon therapy were determined from measured data. Dose–risk models based on the Biological Effects of Ionization Radiation VII report were used to estimate the risk of second cancer in eight tissues/organs. Baseline predictions of the relative risk for each organ were always less for Proton CSI than for photon CSI at all attained ages. The total lifetime attributable risk of the incidence of second cancer considered after Proton CSI was much lower than that after photon CSI, and the ratio of lifetime risk was 0.18. Uncertainty analysis revealed that the qualitative findings of this study were insensitive to any plausible changes of dose–risk models and mean radiation weighting factor for neutrons. Proton therapy confers lower predicted risk of second cancer than photon therapy for the pediatric medulloblastoma patient.
Nancy J Tarbell - One of the best experts on this subject based on the ideXlab platform.
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clinical outcomes among children with standard risk medulloblastoma treated with Proton and photon radiation therapy a comparison of disease control and overall survival
International Journal of Radiation Oncology Biology Physics, 2016Co-Authors: Bree R Eaton, Shannon M Macdonald, Natia Esiashvili, Sungjin Kim, Elizabeth A Weyman, Lauren T Thornton, Claire Mazewski, Tobey J Macdonald, David H Ebb, Nancy J TarbellAbstract:Purpose The purpose of this study was to compare long-term disease control and overall survival between children treated with Proton and photon radiation therapy (RT) for standard-risk medulloblastoma. Methods and Materials This multi-institution cohort study includes 88 children treated with chemotherapy and Proton (n=45) or photon (n=43) RT between 2000 and 2009. Overall survival (OS), recurrence-free survival (RFS), and patterns of failure were compared between the 2 cohorts. Results Median (range) age was 6 years old at diagnosis (3-21 years) for Proton patients versus 8 years (3-19 years) for photon patients ( P =.011). Cohorts were similar with respect to sex, histology, extent of surgical resection, craniospinal irradiation (CSI) RT dose, total RT dose, whether the RT boost was delivered to the posterior fossa (PF) or tumor bed (TB), time from surgery to RT start, or total duration of RT. RT consisted of a median (range) CSI dose of 23.4 Gy (18-27 Gy) and a boost of 30.6 Gy (27-37.8 Gy). Median follow-up time is 6.2 years (95% confidence interval [CI]: 5.1-6.6 years) for Proton patients versus 7.0 years (95% CI: 5.8-8.9 years) for photon patients. There was no significant difference in RFS or OS between patients treated with Proton versus photon RT; 6-year RFS was 78.8% versus 76.5% ( P =.948) and 6-year OS was 82.0% versus 87.6%, respectively ( P =.285). On multivariate analysis, there was a trend for longer RFS with females ( P =.058) and higher CSI dose ( P =.096) and for longer OS with females ( P =.093). Patterns of failure were similar between the 2 cohorts ( P =.908). Conclusions Disease control with Proton and photon radiation therapy appears equivalent for standard risk medulloblastoma.
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second nonocular tumors among survivors of retinoblastoma treated with contemporary photon and Proton radiotherapy
Cancer, 2014Co-Authors: Roshan V Sethi, Torunn I Yock, Beow Y Yeap, Helen A Shih, Kent W Mouw, Robert A Petersen, John E Munzenrider, Eric F Grabowski, Carlos Rodriguezgalindo, Nancy J TarbellAbstract:BACKGROUND The leading cause of death among patients with hereditary retinoblastoma is second malignancy. Despite its high rate of efficacy, radiotherapy (RT) is often avoided due to fear of inducing a secondary tumor. Proton RT allows for significant sparing of nontarget tissue. The current study compared the risk of second malignancy in patients with retinoblastoma who were treated with photon and Proton RT. METHODS A retrospective review was performed of patients with retinoblastoma who were treated with Proton RT at the Massachusetts General Hospital or photon RT at Boston Children's Hospital between 1986 and 2011. RESULTS A total of 86 patients were identified, 55 of whom received Proton RT and 31 of whom received photon RT. Patients were followed for a median of 6.9 years (range, 1.0 years-24.4 years) in the Proton cohort and 13.1 years (range, 1.4 years-23.9 years) in the photon cohort. The 10-year cumulative incidence of RT-induced or in-field second malignancies was significantly different between radiation modalities (Proton vs photon: 0% vs 14%; P = .015). The 10-year cumulative incidence of all second malignancies was also different, although with borderline significance (5% vs 14%; P = .120). CONCLUSIONS Retinoblastoma is highly responsive to radiation. The central objection to the use of RT, the risk of second malignancy, is based on studies of patients treated with antiquated, relatively nonconformal techniques. The current study is, to the authors' knowledge, the first to present a series of patients treated with the most conformal of the currently available external-beam RT modalities. Although longer follow-up is necessary, the preliminary data from the current study suggest that Proton RT significantly lowers the risk of RT-induced malignancy. Cancer 2014;120:126–133. © 2013 American Cancer Society.
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cost effectiveness of Proton therapy compared with photon therapy in the management of pediatric medulloblastoma
Cancer, 2013Co-Authors: Raymond Mailhot B Vega, Torunn I Yock, Nancy J Tarbell, Marc R Bussiere, Jona A Hattangadi, Abby S Hollander, Jeff M Michalski, Shannon M MacdonaldAbstract:BACKGROUND: Proton therapy has been a hotly contested issue in both scientific publications and lay media. Proponents cite the modality's ability to spare healthy tissue, but critics claim the benefit gained from its use does not validate its cost compared with photon therapy. The objective of this study was to evaluate the cost effectiveness of Proton therapy versus photon therapy in the management of pediatric medulloblastoma. METHODS: A cost-effective analysis was performed from the societal perspective using a Monte Carlo simulation model. A population of pediatric medulloblastoma survivors aged 18 years was studied who had received treatment at age 5 years and who were at risk of developing 10 adverse events, such as growth hormone deficiency, coronary artery disease, ototoxicity, secondary malignant neoplasm, and death. Costing data included the cost of investment and the costs of diagnosis and management of adverse health states from institutional and Medicare data. Longitudinal outcomes data and recent modeling studies informed risk parameters for the model. Incremental cost-effectiveness ratios were used to measure outcomes. RESULTS: Results from the base case demonstrated that Proton therapy was associated with higher quality-adjusted life years and lower costs; therefore, it dominated photon therapy. In 1-way sensitivity analyses, Proton therapy remained the more attractive strategy, either dominating photon therapy or having a very low cost per quality-adjust life year gained. Probabilistic sensitivity analysis illustrated the domination of Proton therapy over photon therapy in 96.4% of simulations. CONCLUSIONS: By using current risk estimates and data on required capital investments, the current study indicated that Proton therapy is a cost-effective strategy for the management of pediatric patients with medulloblastoma compared with standard of care photon therapy.
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Proton radiotherapy for orbital rhabdomyosarcoma clinical outcome and a dosimetric comparison with photons
International Journal of Radiation Oncology Biology Physics, 2005Co-Authors: Torunn I Yock, Robert C Schneider, Alison M Friedmann, Judith Adams, Barbara C Fullerton, Nancy J TarbellAbstract:Background: Over 85% of pediatric orbital rhabdomyosarcoma (RMS) are cured with combined chemotherapy and radiation. However, the late effects of photon radiation compromise function and cosmetic outcome. Proton radiation can provide excellent tumor dose distributions while sparing normal tissues better than photon irradiation. Methods and Materials: Conformal 3D photon and Proton radiotherapy plans were generated for children treated with Proton irradiation for orbital RMS at Massachusetts General Hospital. Dose–volume histograms (90%, 50%, 10%) were generated and compared for important orbital and central nervous system structures. Average percentages of total dose prescribed were calculated based on the 3 dose–volume histogram levels for normal orbital structures for both the Proton and photon plans. The percent of normal tissue spared by using Protons was calculated. Results: Seven children were treated for orbital rhabdomyosarcoma with Proton irradiation and standard chemotherapy. The median follow-up is 6.3 years (range, 3.5–9.7 years). Local and distant controls compare favorably to those in other published accounts. There was an advantage in limiting the dose to the brain, pituitary, hypothalamus, temporal lobes, and ipsilateral and contralateral orbital structures. Tumor size and location affect the degree of sparing of normal structures. Conclusions: Fractionated Proton radiotherapy is superior to 3D conformal photon radiation in the treatment of orbital RMS. Proton therapy maintains excellent tumor coverage while reducing the radiation dose to adjacent normal structures. Proton radiation therapy minimizes long-term side effects.