International Journal of Particle Therapy最新文献

{"title":"Cardiac-Sparing and Breast-Sparing Whole Lung Irradiation Using Intensity-Modulated Proton Therapy.","authors":"Ru Xin Wong, Jacqueline Faught, Melissa Gargone, William Myers, Matthew Krasin, Austin Faught, Sahaja Acharya","doi":"10.14338/IJPT-20-00079.1","DOIUrl":"10.14338/IJPT-20-00079.1","url":null,"abstract":"<p><strong>Purpose: </strong>Whole lung irradiation (WLI) is indicated for certain pediatric patients with lung metastases. This study investigated whether WLI delivered as intensity-modulated proton therapy (IMPT) could significantly spare the heart and breasts when compared with conventional WLI delivered with anteroposterior/posteroanterior photon fields and with intensity-modulated photon therapy (IMRT) WLI.</p><p><strong>Materials and methods: </strong>Conventional, IMRT, and IMPT plans were generated for 5 patients (aged 5-22 years). The prescription dose was 16.5 GyRBE in 1.5-GyRBE fractions. Conventional plans used 6-MV photons prescribed to the midline and a field-in-field technique to cover the planning target volume (the internal target volume [ITV] + 1 cm). IMRT plans used 6-MV photons with a 7-beam arrangement with dose prescribed to the planning target volume. IMPT plans used scenario-based optimization with 5% range uncertainty and 5-mm positional uncertainty to cover the ITV robustly. Monte Carlo dose calculation was used for all IMPT plans. Doses were compared with paired Student <i>t</i> test.</p><p><strong>Results: </strong>The ITV Dmean was similar for the IMPT, conventional, and IMRT plans, but the IMPT plans had a lower Dmin and a higher Dmax at tissue interfaces than conventional plans (Dmean ratio: 0.96, <i>P</i> > .05; Dmin ratio: 0.9, <i>P</i> < .001; Dmax ratio: 1.1, <i>P</i> = .014). Dmeans for breast and heart substructures were lower with IMPT plans than with conventional/IMRT plans (heart ratios, 0.63:0.73; left ventricle ratios, 0.61:0.72; right ventricle ratios, 0.45:0.57; left atrium ratios, 0.79:0.85; right atrium ratios, 0.81:0.86; left breast ratios, 0.40:0.51; right breast ratio, 0.46:0.52; all <i>P</i> < .05).</p><p><strong>Conclusions: </strong>IMPT resulted in comparable ITV coverage and lower mean doses to the heart and breasts when compared with other techniques. Whole lung irradiation delivered as IMPT warrants prospective evaluation in pediatric patients.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"7 4","pages":"65-73"},"PeriodicalIF":1.7,"publicationDate":"2021-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8019572/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25570045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proceedings to the 2020 Online Conference of the Particle Therapy Cooperative Group (PTCOG2020Online): 13-14 September 2020Organized by the Particle Therapy Cooperative Group (PTCOG), this special online meeting featured abstracts and programs that enabled the communication and cross fertilization for which PTCOG meetings are known.","authors":"","doi":"10.14338/IJPT.20-PTCOG-7.4","DOIUrl":"https://doi.org/10.14338/IJPT.20-PTCOG-7.4","url":null,"abstract":"","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"7 4","pages":"74-199"},"PeriodicalIF":1.7,"publicationDate":"2021-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8019577/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25570046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dosimetric Effect of Biozorb Markers for Accelerated Partial Breast Irradiation in Proton Therapy.","authors":"Melton D Parham,&nbsp;Salahuddin Ahmad,&nbsp;Hosang Jin","doi":"10.14338/IJPT-20-00077.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00077.1","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate dosimetric implications of biodegradable Biozorb (BZ) markers for proton accelerated partial breast irradiation (APBI) plans.</p><p><strong>Materials and methods: </strong>Six different BZs were placed within in-house breast phantoms to acquire computed tomography (CT) images. A contour correction method with proper mass density overriding for BZ titanium clip and surrounding tissue was applied to minimize inaccuracies found in the CT images in the RayStation planning system. Each breast phantom was irradiated by a monoenergetic proton beam (103.23 MeV and 8×8 cm²) using a pencil-beam scanning proton therapy system. For a range perturbation study, doses were measured at 5 depths below the breast phantoms by using an ionization chamber and compared to the RayStation calculations with 3 scenarios for the clip density: the density correction method (S1: 1.6 g/cm³), raw CT (S2), and titanium density (S3: 4.54 g/cm³). For the local dose perturbation study, the radiographic EDR2 film was placed at 0 and 2 cm below the phantoms and compared to the RayStation calculations. Clinical effects of the perturbations were retrospectively examined with 10 APBI plans for the 3 scenarios (approved by our institutional review board).</p><p><strong>Results: </strong>In the range perturbation study, the S1 simulation showed a good agreement with the chamber measurements, while excess pullbacks of 1∼2 mm were found in the S2 and S3 simulations. The film study showed local dose shadowing and perturbation by the clips that RayStation could not predict. In the plan study, no significant differences in the plan quality were found among the 3 scenarios. However, substantial range pullbacks were observed for S3.</p><p><strong>Conclusion: </strong>The density correction method could minimize the dose and range difference between measurement and RayStation prediction. It should be avoided to simply override the known physical density of the BZ clips for treatment planning owing to overestimation of the range pullback.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"7 4","pages":"19-28"},"PeriodicalIF":1.7,"publicationDate":"2021-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8019574/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25570041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proton Radiotherapy Could Reduce the Risk of Fatal Second Cancers for Children with Intracranial Tumors in Low- and Middle-Income Countries.","authors":"Kyle J Gallagher, Bassem Youssef, Rola Georges, Anita Mahajan, Joelle Ann Feghali, Racile Nabha, Zeina Ayoub, Wassim Jalbout, Phillip J Taddei","doi":"10.14338/IJPT-20-00041.1","DOIUrl":"10.14338/IJPT-20-00041.1","url":null,"abstract":"<p><strong>Purpose: </strong>To test our hypothesis that, for young children with intracranial tumors, proton radiotherapy in a high-income country does not reduce the risk of a fatal subsequent malignant neoplasm (SMN) compared with photon radiotherapy in low- and middle-income countries.</p><p><strong>Materials and methods: </strong>We retrospectively selected 9 pediatric patients with low-grade brain tumors who were treated with 3-dimensional conformal radiation therapy in low- and middle-income countries. Images and contours were deidentified and transferred to a high-income country proton therapy center. Clinically commissioned treatment planning systems of each academic hospital were used to calculate absorbed dose from the therapeutic fields. After fusing supplemental computational phantoms to the patients' anatomies, models from the literature were applied to calculate stray radiation doses. Equivalent doses were determined in organs and tissues at risk of SMNs, and the lifetime attributable risk of SMN mortality (<i>LAR</i>) was predicted using a dose-effect model. Our hypothesis test was based on the average of the ratios of <i>LARs</i> from proton therapy to that of photon therapy ()(H₀: = 1; H _<i>A</i> : < 1).</p><p><strong>Results: </strong>Proton therapy reduced the equivalent dose in organs at risk for SMNs and <i>LARs</i> compared with photon therapy for which the for the cohort was 0.69 ± 0.10, resulting in the rejection of H₀ (<i>P</i> < .001, α = 0.05). We observed that the younger children in the cohort (2-4 years old) were at a factor of approximately 2.5 higher <i>LAR</i> compared with the older children (8-12 years old).</p><p><strong>Conclusion: </strong>Our findings suggest that proton radiotherapy has the strong potential of reducing the risk of fatal SMNs in pediatric patients with intracranial tumors if it were made available globally.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"7 4","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8019578/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25572139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Learning-Based Stopping Power Mapping on Dual-Energy CT for Proton Radiation Therapy.","authors":"Tonghe Wang,&nbsp;Yang Lei,&nbsp;Joseph Harms,&nbsp;Beth Ghavidel,&nbsp;Liyong Lin,&nbsp;Jonathan J Beitler,&nbsp;Mark McDonald,&nbsp;Walter J Curran,&nbsp;Tian Liu,&nbsp;Jun Zhou,&nbsp;Xiaofeng Yang","doi":"10.14338/IJPT-D-20-00020.1","DOIUrl":"https://doi.org/10.14338/IJPT-D-20-00020.1","url":null,"abstract":"<p><strong>Purpose: </strong>Dual-energy computed tomography (DECT) has been used to derive relative stopping power (RSP) maps by obtaining the energy dependence of photon interactions. The DECT-derived RSP maps could potentially be compromised by image noise levels and the severity of artifacts when using physics-based mapping techniques. This work presents a noise-robust learning-based method to predict RSP maps from DECT for proton radiation therapy.</p><p><strong>Materials and methods: </strong>The proposed method uses a residual attention cycle-consistent generative adversarial network to bring DECT-to-RSP mapping close to a 1-to-1 mapping by introducing an inverse RSP-to-DECT mapping. To evaluate the proposed method, we retrospectively investigated 20 head-and-neck cancer patients with DECT scans in proton radiation therapy simulation. Ground truth RSP values were assigned by calculation based on chemical compositions and acted as learning targets in the training process for DECT datasets; they were evaluated against results from the proposed method using a leave-one-out cross-validation strategy.</p><p><strong>Results: </strong>The predicted RSP maps showed an average normalized mean square error of 2.83% across the whole body volume and an average mean error less than 3% in all volumes of interest. With additional simulated noise added in DECT datasets, the proposed method still maintained a comparable performance, while the physics-based stoichiometric method suffered degraded inaccuracy from increased noise level. The average differences from ground truth in dose volume histogram metrics for clinical target volumes were less than 0.2 Gy for D_95% and D_max with no statistical significance. Maximum difference in dose volume histogram metrics of organs at risk was around 1 Gy on average.</p><p><strong>Conclusion: </strong>These results strongly indicate the high accuracy of RSP maps predicted by our machine-learning-based method and show its potential feasibility for proton treatment planning and dose calculation.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"7 3","pages":"46-60"},"PeriodicalIF":1.7,"publicationDate":"2021-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7886267/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25383385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Probability-Based Investigation on the Setup Robustness of Pencil-beam Proton Radiation Therapy for Skull-Base Meningioma.","authors":"Wei Zou,&nbsp;Goldie Kurtz,&nbsp;Mayisha Nakib,&nbsp;Brendan Burgdorf,&nbsp;Murat Alp,&nbsp;Taoran Li,&nbsp;Robert Lustig,&nbsp;Ying Xiao,&nbsp;Lei Dong,&nbsp;Alireza Kassaee,&nbsp;Michelle Alonso-Basanta","doi":"10.14338/IJPT-20-00009.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00009.1","url":null,"abstract":"<p><strong>Introduction: </strong>The intracranial skull-base meningioma is in proximity to multiple critical organs and heterogeneous tissues. Steep dose gradients often result from avoiding critical organs in proton treatment plans. Dose uncertainties arising from setup errors under image-guided radiation therapy are worthy of evaluation.</p><p><strong>Patients and methods: </strong>Fourteen patients with skull-base meningioma were retrospectively identified and planned with proton pencil beam scanning (PBS) single-field uniform dose (SFUD) and multifield optimization (MFO) techniques. The setup uncertainties were assigned a probability model on the basis of prior published data. The impact on the dose distribution from nominal 1-mm and large, less probable setup errors, as well as the cumulative effect, was analyzed. The robustness of SFUD and MFO planning techniques in these scenarios was discussed.</p><p><strong>Results: </strong>The target coverage was reduced and the plan dose hot spot increased by all setup uncertainty scenarios regardless of the planning techniques. For 1 mm nominal shifts, the deviations in clinical target volume (CTV) coverage D99% was -11 ± 52 cGy and -45 ± 147 cGy for SFUD and MFO plans. The setup uncertainties affected the organ at risk (OAR) dose both positively and negatively. The statistical average of the setup uncertainties had <100 cGy impact on the plan qualities for all patients. The cumulative deviations in CTV D95% were 1 ± 34 cGy and -7 ± 18 cGy for SFUD and MFO plans.</p><p><strong>Conclusion: </strong>It is important to understand the impact of setup uncertainties on skull-base meningioma, as the tumor target has complex shape and is in proximity to multiple critical organs. Our work evaluated the setup uncertainty based on its probability distribution and evaluated the dosimetric consequences. In general, the SFUD plans demonstrated more robustness than the MFO plans in target coverages and brainstem dose. The probability-weighted overall effect on the dose distribution is small compared to the dosimetric shift during single fraction.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"7 3","pages":"34-45"},"PeriodicalIF":1.7,"publicationDate":"2021-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7886272/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25383383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Patient-Reported Outcomes after Intensity-Modulated Proton Therapy for Oropharynx Cancer.","authors":"Houda Bahig,&nbsp;Brandon G Gunn,&nbsp;Adam S Garden,&nbsp;Rong Ye,&nbsp;Kate Hutcheson,&nbsp;David I Rosenthal,&nbsp;Jack Phan,&nbsp;Clifton D Fuller,&nbsp;William H Morrison,&nbsp;Jay Paul Reddy,&nbsp;Sweet Ping Ng,&nbsp;Neil D Gross,&nbsp;Erich M Sturgis,&nbsp;Renata Ferrarotto,&nbsp;Maura Gillison,&nbsp;Steven J Frank","doi":"10.14338/IJPT-20-00081.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00081.1","url":null,"abstract":"<p><strong>Purpose: </strong>To report patient-reported outcomes (PROs) derived from the Functional Assessment of Cancer Therapy-Head and Neck (FACT-HN) tool, in patients with oropharynx cancer (OPC) treated with intensity-modulated proton therapy (IMPT) in the context of first-course irradiation.</p><p><strong>Materials and methods: </strong>Patients with locally advanced OPC treated with radical IMPT between 2011 and 2018 were included in a prospective registry. FACT-HN scores were measured serially during and 24 months following IMPT. PRO changes in the FACT-HN scores over time were assessed with mixed-model analysis.</p><p><strong>Results: </strong>Fifty-seven patients met inclusion criteria. Median age was 60 years (range, 41-84), and 91% had human papillomavirus-associated disease. In total, 28% received induction chemotherapy and 68% had concurrent chemotherapy. Compliance to FACT-HN questionnaire completion was 59%, 48%, and 42% at 6, 12, and 24 months after treatment, respectively. The mean FACT-General (G), FACT-Total, and FACT-Trial Outcome Index (TOI) score changes were statistically and clinically significant relative to baseline from week 3 of treatment up to week 2 after treatment. Nadir was reached at week 6 of treatment for all scores, with maximum scores dropping by 15%, 20%, and 39% compared to baseline for FACT-G, FACT-Total, and FACT-TOI, respectively. Subdomain scores of physical well-being, functional well-being, and head and neck additional concerns decreased from baseline during treatment and returned to baseline at week 4 after treatment.</p><p><strong>Conclusions: </strong>IMPT was associated with a favorable PRO trajectory, characterized by an acute decline followed by rapid recovery to baseline. This study establishes the expected acute, subacute, and chronic trajectory of PROs for patients undergoing IMPT for OPC.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"213-222"},"PeriodicalIF":1.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8270092/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10445159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Biological Basis for Enhanced Effects of Proton Radiation Therapy Relative to Photon Radiation Therapy for Head and Neck Squamous Cell Carcinoma.","authors":"Li Wang,&nbsp;Piero Fossati,&nbsp;Harald Paganetti,&nbsp;Li Ma,&nbsp;Maura Gillison,&nbsp;Jeffrey N Myers,&nbsp;Eugen Hug,&nbsp;Steven J Frank","doi":"10.14338/IJPT-20-00070.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00070.1","url":null,"abstract":"<p><p>Head and neck squamous cell carcinomas (HNSCCs) often present as local-regionally advanced disease at diagnosis, for which a current standard of care is x-ray-based radiation therapy, with or without chemotherapy. This approach provides effective local regional tumor control, but at the cost of acute and late toxicity that can worsen quality of life and contribute to mortality. For patients with human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (SCC) in particular, for whom the prognosis is generally favorable, de-escalation of the radiation dose to surrounding normal tissues without diminishing the radiation dose to tumors is desired to mitigate radiation-related toxic effects. Proton radiation therapy (PRT) may be an excellent de-escalation strategy because of its physical properties (that eliminate unnecessary radiation to surrounding tissues) and because of its biological properties (including tumor-specific variations in relative biological effectiveness [RBE] and linear energy transfer [LET]), in combination with concurrent systemic therapy. Early clinical evidence has shown that compared with x-ray-based radiation therapy, PRT offers comparable disease control with fewer and less severe treatment-related toxicities that can worsen the quality of life for patients with HNSCC. Herein, we review aspects of the biological basis of enhanced HNSCC cell response to proton versus x-ray irradiation in terms of radiation-induced gene and protein expression, DNA damage and repair, cell death, tumor immune responses, and radiosensitization of tumors.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"3-13"},"PeriodicalIF":1.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8270087/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9518170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proton Therapy for Head and Neck Cancer: A 12-Year, Single-Institution Experience.","authors":"G Brandon Gunn,&nbsp;Adam S Garden,&nbsp;Rong Ye,&nbsp;Noveen Ausat,&nbsp;Kristina R Dahlstrom,&nbsp;William H Morrison,&nbsp;C David Fuller,&nbsp;Jack Phan,&nbsp;Jay P Reddy,&nbsp;Shalin J Shah,&nbsp;Lauren L Mayo,&nbsp;Stephen G Chun,&nbsp;Gregory M Chronowski,&nbsp;Amy C Moreno,&nbsp;Jeffery N Myers,&nbsp;Ehab Y Hanna,&nbsp;Bita Esmaeli,&nbsp;Maura L Gillison,&nbsp;Renata Ferrarotto,&nbsp;Katherine A Hutcheson,&nbsp;Mark S Chambers,&nbsp;Lawrence E Ginsberg,&nbsp;Adel K El-Naggar,&nbsp;David I Rosenthal,&nbsp;Xiaorong Ronald Zhu,&nbsp;Steven J Frank","doi":"10.14338/IJPT-20-00065.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00065.1","url":null,"abstract":"<p><strong>Purpose: </strong>To characterize our experience and the disease control and toxicity of proton therapy (PT) for patients with head and neck cancer (HNC).</p><p><strong>Patients and methods: </strong>Clinical outcomes for patients with HNC treated with PT at our institution were prospectively collected in 2 institutional review board-approved prospective studies. Descriptive statistics were used to summarize patient characteristics and outcomes. Overall survival, local-regional control, and disease-free survival were estimated by the Kaplan-Meier method. Treatment-related toxicities were recorded according to the Common Terminology Criteria for Adverse Events (version 4.03) scale.</p><p><strong>Results: </strong>The cohort consisted of 573 patients treated from February 2006 to June 2018. Median patient age was 61 years. Oropharynx (33.3%; n = 191), paranasal sinus (11%; n = 63), and periorbital tissues (11%; n = 62) were the most common primary sites. Patients with T3/T4 or recurrent disease comprised 46% (n = 262) of the cohort. The intent of PT was definitive in 53% (n = 303), postoperative in 37% (n = 211), and reirradiation in 10% (n = 59). Median dose was 66 Gy (radiobiological equivalent). Regarding systemic therapy, 43% had received concurrent (n = 244), 3% induction (n = 19), and 15% (n = 86) had both. At a median follow-up of 2.4 years, 88 patients (15%) had died and 127 (22%) developed disease recurrence. The overall survival, local-regional control, and disease-free survival at 2 and 5 years were, respectively, 87% and 75%, 87% and 78%, and 74% and 63%. Maximum toxicity (acute or late) was grade 3 in 293 patients (51%), grade 2 in 234 patients (41%), and grade 1 in 31 patients (5%). There were 381 acute grade 3 and 190 late grade 3 unique toxicities across 212 (37%) and 150 (26%) patients, respectively. There were 3 late-grade 4 events across 2 patients (0.3%), 2 (0.3%) acute-grade 5, and no (0%) late-grade 5 events.</p><p><strong>Conclusions: </strong>The overall results from this prospective study of our initial decade of experience with PT for HNC show favorable disease control and toxicity outcomes in a multidisease-site cohort and provide a reference benchmark for future comparison and study.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"108-118"},"PeriodicalIF":1.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8270083/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9162306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proton versus Photon Breath-Hold Radiation for Left-Sided Breast Cancer after Breast-Conserving Surgery: A Dosimetric Comparison.","authors":"Dodul Mondal, Sachin R Jhawar, Rihan Millevoi, Bruce G Haffty, Rahul R Parikh","doi":"10.14338/IJPT-20-00026.1","DOIUrl":"10.14338/IJPT-20-00026.1","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Purpose: &lt;/strong&gt;Radiation to breast, chest wall, and/or regional nodes is an integral component of breast cancer management in many situations. Irradiating left-sided breast and/or regional nodes may be technically challenging because of cardiac tolerance and subsequent risk of long-term cardiac complications. Deep inspiratory breath-hold (DIBH) technique physically separates cardiac structures away from radiation target volume, thus reducing cardiac dose with either photon (Ph) or proton beam therapy (PBT). The utility of combining PBT with DIBH is less well understood.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods and materials: &lt;/strong&gt;We compared photon-DIBH (Ph-DIBH) versus proton DIBH (Pr-DIBH) for different planning parameters, including target coverage and organ at risk (OAR) sparing. Necessary ethical permission was obtained from the institutional review board. Ten previous patients with irradiated, intact, left-sided breast and Ph-DIBH were replanned with PBT for dosimetric comparison. Clinically relevant normal OARs were contoured, and Ph plans were generated with parallel, opposed tangent beams and direct fields for supraclavicular and/or axillae whenever required. For proton planning, all targets were delineated individually and best possible coverage of planning target volume was achieved. Dose-volume histogram was analyzed to determine the difference in doses received by different OARs. Minimum and maximum dose (&lt;i&gt;D&lt;sub&gt;min&lt;/sub&gt;&lt;/i&gt; and &lt;i&gt;D&lt;sub&gt;max&lt;/sub&gt;&lt;/i&gt; ) as well as dose received by a specific volume of OAR were compared. Each patient's initial plan (Ph-DIBH) was used as a control for comparing newly devised PBT plan (Pr-DIBH). Matched, paired &lt;i&gt;t&lt;/i&gt; tests were applied to determine any significant differences between the 2 plans.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Both the plans were adequate in target coverage. Dose to cardiac structure subunits and ipsilateral lung were significantly reduced with the proton breath-hold technique. Significant dose reduction with Pr-DIBH was observed in comparison to Ph-DIBH for mean dose (&lt;i&gt;D&lt;/i&gt; &lt;sub&gt;mean&lt;/sub&gt;) to the heart (0.23 Gy versus 1.19 Gy; &lt;i&gt;P&lt;/i&gt; &lt; .001); &lt;i&gt;D&lt;/i&gt; &lt;sub&gt;mean&lt;/sub&gt; to the left ventricle (0.25 Gy versus 1.7 Gy; &lt;i&gt;P&lt;/i&gt; &lt; .001); &lt;i&gt;D&lt;/i&gt; &lt;sub&gt;mean&lt;/sub&gt;, &lt;i&gt;D&lt;/i&gt; &lt;sub&gt;max&lt;/sub&gt;, and the half-maximal dose to the left anterior descending artery (1.15 Gy versus 5.54 Gy; &lt;i&gt;P&lt;/i&gt; &lt; .003; 7.7 Gy versus 22.15 Gy; &lt;i&gt;P&lt;/i&gt; &lt; .007; 1.61 Gy versus 4.42 Gy, &lt;i&gt;P&lt;/i&gt; &lt; .049); &lt;i&gt;D&lt;/i&gt; &lt;sub&gt;max&lt;/sub&gt; of the left circumflex coronary artery (0.13 Gy versus 1.35 Gy; &lt;i&gt;P&lt;/i&gt; &lt; .001) and &lt;i&gt;D&lt;/i&gt; &lt;sub&gt;mean&lt;/sub&gt;, the volume to the ipsilateral lung receiving 20 Gy and 5 Gy (2.28 Gy versus 8.04 Gy; &lt;i&gt;P&lt;/i&gt; &lt; .001; 2.36 Gy versus 15.54 Gy, &lt;i&gt;P&lt;/i&gt; &lt; .001; 13.9 Gy versus 30.28 Gy; &lt;i&gt;P&lt;/i&gt; = .002). However, skin dose and contralateral breast dose were not significantly improved with proton.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;This comparative dosimetric study showed significant benefit of Pr","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"7 3","pages":"24-33"},"PeriodicalIF":1.7,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7886268/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25383382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}