International Journal of Particle Therapy最新文献

{"title":"Radiation Necrosis with Proton Therapy in a Patient with Aarskog-Scott Syndrome and Medulloblastoma.","authors":"Vidya Puthenpura,&nbsp;Nicholas J DeNunzio,&nbsp;Xue Zeng,&nbsp;Drosoula Giantsoudi,&nbsp;Mariam Aboian,&nbsp;David Ebb,&nbsp;Kristopher T Kahle,&nbsp;Torunn I Yock,&nbsp;Asher M Marks","doi":"10.14338/IJPT-21-00013.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00013.1","url":null,"abstract":"<p><strong>Purpose: </strong>Medulloblastoma is known to be associated with multiple cancer-predisposition syndromes. In this article, we explore a possible association among a patient's Aarskog-Scott syndrome, development of medulloblastoma, and subsequent brainstem radiation necrosis.</p><p><strong>Case presentation: </strong>A 5-year-old male with Aarskog-Scott syndrome initially presented to his pediatrician with morning emesis, gait instability, and truncal weakness. He was ultimately found to have a posterior fossa tumor with pathology consistent with group 3 medulloblastoma. After receiving a gross total resection and standard proton beam radiation therapy with concurrent vincristine, he was noted to develop brainstem radiation necrosis, for which he underwent therapy with high-dose dexamethasone, bevacizumab, and hyperbaric oxygen therapy with radiographic improvement and clinical stabilization.</p><p><strong>Conclusion: </strong>Based on several possible pathologic correlates in the FDG1 pathway, there exists a potential association between this patient's Aarskog-Scott syndrome and medulloblastoma, which needs to be investigated further. In patients with underlying, rare genetic syndromes, further caution should be taken when evaluating chemotherapy and radiation dosimetry planning.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"58-65"},"PeriodicalIF":1.7,"publicationDate":"2021-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768897/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592767","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":"Insurance Approval for Definitive Proton Therapy for Prostate Cancer.","authors":"William M Mendenhall,&nbsp;Eric D Brooks,&nbsp;Stephanie Smith,&nbsp;Christopher G Morris,&nbsp;Curtis B Bryant,&nbsp;Randal H Henderson,&nbsp;Romaine C Nichols,&nbsp;Kathy McIntyre,&nbsp;Stuart L Klein,&nbsp;Nancy P Mendenhall","doi":"10.14338/IJPT-21-00002.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00002.1","url":null,"abstract":"<p><strong>Purpose: </strong>To determine factors that influence insurance approval for definitive proton therapy (PT) for prostate cancer.</p><p><strong>Materials and methods: </strong>Between 2014 and 2018, 1592 insured patients with localized prostate cancer were evaluated and recommended to undergo definitive PT; 547 patients (34.4%) had commercial insurance, whereas 1045 patients (65.6%) had Medicare/Medicaid. Of those with Medicare, 164 patients (15.7%) had Medicare alone; 677 (64.8%) had supplemental plans; and 204 (19.5%) had secondary commercial insurance. Insurance that \"covered\" PT for prostate cancer implied that it was an indication designated in the coverage policy. \"Not covered\" means that the insurance policy did not list prostate cancer as an indication for PT. Of all 1592 patients, 1263 (79.3%) belonged to plans that covered PT per policy. However, approval for PT was still required via medical review for 619 patients (38.9%), comparative dosimetry for 56 patients (3.5%), peer-to-peer discussion for 234 patients (14.7%), and administrative law judge hearings for 3 patients (<0.1%). Multivariate analyses of factors affecting approval were conducted, including risk group (low/intermediate versus high), insurance type (commercial versus Medicare/Medicaid), whether PT was included as a covered benefit under the plan (covered versus not covered), and time period (2014-16 versus 2017 versus 2018).</p><p><strong>Results: </strong>On multivariate analysis, factors affecting PT approval for prostate treatment included coverage of PT per policy (97.1% had approval with insurance that covered PT versus 48.6% whose insurance did not cover PT; <i>P</i> < .001); insurance type (32.5% had approval with commercial insurance versus 97.4% with Medicare; <i>P</i> < .001); and time, with 877/987 patients (88.9%) approved between 2014 and 2016, 255/312 patients (81.7%) approved during 2017, and 255/293 patients (87.0%) approved thereafter (<i>P</i> = .02). Clinical factors, including risk group, had no bearing on insurance approval (<i>P</i> = .44).</p><p><strong>Conclusion: </strong>Proton insurance approval for prostate cancer has decreased, is most influenced by the type of insurance a patient belongs to, and is unrelated to clinical factors (risk group) in this study. More work is needed to help navigate appropriate access to care and to assist patients seeking definitive PT for prostate cancer treatment.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"36-42"},"PeriodicalIF":1.7,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768894/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592763","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":"Measuring Radiation Toxicity Using Circulating Cell-Free DNA in Prostate Cancer Patients.","authors":"Natalie A Lockney,&nbsp;Randal H Henderson,&nbsp;Steven G Swarts,&nbsp;Zhenhuan Zhang,&nbsp;Bingrong Zhang,&nbsp;Jennifer Li,&nbsp;Robert A Zlotecki,&nbsp;Christopher G Morris,&nbsp;Katherine A Casey-Sawicki,&nbsp;Paul G Okunieff","doi":"10.14338/IJPT-D-21-00008","DOIUrl":"https://doi.org/10.14338/IJPT-D-21-00008","url":null,"abstract":"<p><strong>Background: </strong>After radiation therapy (RT), circulating plasma cell-free DNA (cfDNA) released in response to RT damage to tissue can be measured within hours. We examined for a correlation between cfDNA measured during the first week of therapy and early and late gastrointestinal (GI) and genitourinary (GU) toxicity.</p><p><strong>Material and methods: </strong>Patients were eligible for enrollment if they planned to receive proton or photon RT for nonmetastatic prostate cancer in the setting of an intact prostate or after prostatectomy. Blood was collected before treatment and on sequential treatment days for the first full week of therapy. Toxicity assessments were performed at baseline, weekly during RT, and 6 months and 12 months after RT. Data were analyzed to examine correlations among patient-reported GI and GU toxicities.</p><p><strong>Results: </strong>Fifty-four patients were evaluable for this study. Four (7%) and 3 (6%) patients experienced acute and late grade 2 GI toxicity, respectively. Twenty-two (41%) and 18 (35%) patients experienced acute and late grade 2 GU toxicity, respectively. No patients developed grade 3 or higher toxicity. Grade 2 acute GI toxicity, but not grade 2 acute GU toxicity, was significantly correlated with pre-RT cfDNA levels and on all days 1, 2, 3, 4, and 5 of RT (<i>P</i> < .005). Grade 2 late GI toxicity, but not GU toxicity, was significantly correlated with pre-RT cfDNA levels (<i>P</i> = .021).</p><p><strong>Conclusions: </strong>Based on this preliminary study, cfDNA levels can potentially predict the subset of patients destined to develop GI toxicity during prostate cancer treatment. Given that the toxicity profiles of the various fractionations and modalities are highly similar, the data support the expectation that cfDNA could provide a biological estimate to complement the dose-volume histogram. A test of this hypothesis is under evaluation in a National Cancer Institute-funded multi-institutional study.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"28-35"},"PeriodicalIF":1.7,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768895/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592762","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":"Comparative Effectiveness of Proton Therapy versus Photon Radiotherapy in Adolescents and Young Adults for Classical Hodgkin Lymphoma.","authors":"James E Bates,&nbsp;Stephanie Terezakis,&nbsp;Christopher G Morris,&nbsp;Avani D Rao,&nbsp;Shuchi Sehgal,&nbsp;Rahul Kumar,&nbsp;Raymond B Mailhot Vega,&nbsp;Nancy P Mendenhall,&nbsp;Bradford S Hoppe","doi":"10.14338/IJPT-21-00011.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00011.1","url":null,"abstract":"<p><strong>Purpose: </strong>Early stage (stages I-II) classical Hodgkin lymphoma (cHL) is a highly curable disease typically diagnosed in adolescents and young adults (AYAs). Proton therapy can also reduce the late toxicity burden in this population, but data on its comparative efficacy with photon radiotherapy in this population are sparse. We assessed outcomes in AYAs with cHL in a multi-institution retrospective review.</p><p><strong>Materials and methods: </strong>We identified 94 patients aged 15 to 40 years with stages I and II cHL treated with radiotherapy as part of their initial treatment between 2008 and 2017. We used Kaplan-Meier analyses and log-rank testing to evaluate survival differences between groups of patients.</p><p><strong>Results: </strong>A total of 91 patients were included in the analysis. The 2-year progression-free survival (PFS) rate was 89%. Of the 12 patients who experienced progression after radiotherapy, 4 occurred out-of-field, 2 occurred in-field, and 6 experienced both in- and out-of-field progression. There was no significant difference in 2-year PFS among AYA patients by radiotherapy dose received (≥ 30 Gy, 91%; < 30 Gy, 86%; <i>P</i> = .82). Likewise, there was no difference in 2-year PFS among patients who received either proton or photon radiotherapy (proton, 94%; photon, 83%; <i>P</i> = .07).</p><p><strong>Conclusion: </strong>Our cohort of AYA patients had comparable outcomes regardless of radiotherapy dose or modality used. For patients with significant risk of radiation-induced late effects, proton therapy is a reasonable treatment modality.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"21-27"},"PeriodicalIF":1.7,"publicationDate":"2021-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768899/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592761","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":"Bone Marrow Suppression during Postoperative Radiation for Bladder Cancer and Comparative Benefit of Proton Therapy-Phase 2 Trial Secondary Analysis.","authors":"Robert H Press,&nbsp;Joseph W Shelton,&nbsp;Chao Zhang,&nbsp;Quang Dang,&nbsp;Sibo Tian,&nbsp;Timothy Shu,&nbsp;Crystal S Seldon,&nbsp;Shaakir Hasan,&nbsp;Ashesh B Jani,&nbsp;Jun Zhou,&nbsp;Mark W McDonald","doi":"10.14338/IJPT-21-00003.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00003.1","url":null,"abstract":"<p><strong>Purpose: </strong>For patients with high-risk bladder cancer (pT3⁺ or N⁺), local regional failure remains a challenge after chemotherapy and cystectomy. An ongoing prospective phase 2 trial (NCT01954173) is examining the role of postoperative photon radiation therapy for high-risk patients using volumetric modulated arc therapy. Proton beam therapy (PBT) may be beneficial in this setting to reduce hematologic toxicity. We evaluated for dosimetric relationships with pelvic bone marrow (PBM) and changes in hematologic counts before and after pelvic radiation therapy and explored the potential of PBT treatment plans to achieve reductions in PBM dose.</p><p><strong>Materials and methods: </strong>All enrolled patients were retrospectively analyzed after pelvic radiation per protocol with 50.4 to 55.8 Gy in 28 to 31 fractions. Comparative PBT plans were generated using pencil-beam scanning and a 3-beam multifield optimization technique. Changes in hematologic nadirs were assessed using paired <i>t</i> test. Correlation of mean nadirs and relative PBM dose levels were assessed using the Pearson correlation coefficient (CC).</p><p><strong>Results: </strong>Eighteen patients with a median age of 70 were analyzed. Mean cell count values after radiation therapy decreased compared with preradiation therapy values for white blood cells (WBCs), absolute neutrophil count (ANC), absolute lymphocyte count (all <i>P</i> < .001), and platelets (<i>P</i> = .03). Increased mean PBM dose was associated with lower nadirs in WBC (Pearson CC -0.593, <i>P</i> = .02), ANC (Pearson CC -0.597, <i>P</i> = .02), and hemoglobin (Pearson CC -0.506, <i>P</i> = .046), whereas the PBM V30 to V40 correlated with lower WBC (Pearson CC -0.512 to -0.618, <i>P</i> < .05), and V20 to V30 correlated with lower ANC (Pearson CC -0.569 to -0.598, <i>P</i> < .04). Comparative proton therapy plans decreased the mean PBM dose from 26.5 Gy to 16.1 Gy (<i>P</i> < .001) and had significant reductions in the volume of PBM receiving doses from 5 to 40 Gy (<i>P</i> < .001).</p><p><strong>Conclusion: </strong>Increased PBM mean dose and V20 to V40 were associated with lower hematologic nadirs. PBT plans reduced PBM dose and may be a valuable strategy to reduce the risk of hematologic toxicity in these patients.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"1-10"},"PeriodicalIF":1.7,"publicationDate":"2021-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768898/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39894933","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":"Facilitating MR-Guided Adaptive Proton Therapy in Children Using Deep Learning-Based Synthetic CT.","authors":"Chuang Wang,&nbsp;Jinsoo Uh,&nbsp;Thomas E Merchant,&nbsp;Chia-Ho Hua,&nbsp;Sahaja Acharya","doi":"10.14338/IJPT-20-00099.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00099.1","url":null,"abstract":"<p><strong>Purpose: </strong>To determine whether self-attention cycle-generative adversarial networks (cycle-GANs), a novel deep-learning method, can generate accurate synthetic computed tomography (sCT) to facilitate adaptive proton therapy in children with brain tumors.</p><p><strong>Materials and methods: </strong>Both CT and T1-weighted magnetic resonance imaging (MRI) of 125 children (ages 1-20 years) with brain tumors were included in the training dataset. A model introducing a self-attention mechanism into the conventional cycle-GAN was created to enhance tissue interfaces and reduce noise. The test dataset consisted of 7 patients (ages 2-14 years) who underwent adaptive planning because of changes in anatomy discovered on MRI during proton therapy. The MRI during proton therapy-based sCT was compared with replanning CT (ground truth).</p><p><strong>Results: </strong>The Hounsfield unit-mean absolute error was significantly reduced with self-attention cycle-GAN, as compared with conventional cycle-GAN (65.3 ± 13.9 versus 88.9 ± 19.3, <i>P</i> < .01). The average 3-dimensional gamma passing rates (2%/2 mm criteria) for the original plan on the anatomy of the day and for the adapted plan were high (97.6% ± 1.2% and 98.9 ± 0.9%, respectively) when using sCT generated by self-attention cycle-GAN. The mean absolute differences in clinical target volume (CTV) receiving 95% of the prescription dose and 80% distal falloff along the beam axis were 1.1% ± 0.8% and 1.1 ± 0.9 mm, respectively. Areas of greatest dose difference were distal to the CTV and corresponded to shifts in distal falloff. Plan adaptation was appropriately triggered in all test patients when using sCT.</p><p><strong>Conclusion: </strong>The novel cycle-GAN model with self-attention outperforms conventional cycle-GAN for children with brain tumors. Encouraging dosimetric results suggest that sCT generation can be used to identify patients who would benefit from adaptive replanning.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 3","pages":"11-20"},"PeriodicalIF":1.7,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8768893/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39592760","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":"Assessment of Knowledge-Based Planning for Prostate Intensity Modulated Proton Therapy.","authors":"Yihang Xu,&nbsp;Nellie Brovold,&nbsp;Jonathan Cyriac,&nbsp;Elizabeth Bossart,&nbsp;Kyle Padgett,&nbsp;Michael Butkus,&nbsp;Tejan Diwanj,&nbsp;Adam King,&nbsp;Alan Dal Pra,&nbsp;Matt Abramowitz,&nbsp;Alan Pollack,&nbsp;Nesrin Dogan","doi":"10.14338/IJPT-20-00088.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00088.1","url":null,"abstract":"<p><strong>Purpose: </strong>To assess the performance of a proton-specific knowledge based planning (KBPP) model in creation of robustly optimized intensity-modulated proton therapy (IMPT) plans for treatment of patients with prostate cancer.</p><p><strong>Materials and methods: </strong>Forty-five patients with localized prostate cancer, who had previously been treated with volumetric modulated arc therapy, were selected and replanned with robustly optimized IMPT. A KBPP model was generated from the results of 30 of the patients, and the remaining 15 patient results were used for validation. The KBPP model quality and accuracy were evaluated with the model-provided organ-at-risk regression plots and metrics. The KBPP quality was also assessed through comparison of expert and KBPP-generated IMPT plans for target coverage and organ-at-risk sparing.</p><p><strong>Results: </strong>The resulting <i>R</i> ² (mean ± SD, 0.87 ± 0.07) between dosimetric and geometric features, as well as the χ² test (1.17 ± 0.07) between the original and estimated data, showed the model had good quality. All the KBPP plans were clinically acceptable. Compared with the expert plans, the KBPP plans had marginally higher dose-volume indices for the rectum V65Gy (0.8% ± 2.94%), but delivered a lower dose to the bladder (-1.06% ± 2.9% for bladder V65Gy). In addition, KBPP plans achieved lower hotspot (-0.67Gy ± 2.17Gy) and lower integral dose (-0.09Gy ± 0.3Gy) than the expert plans did. Moreover, the KBPP generated better plans that demonstrated slightly greater clinical target volume V95 (0.1% ± 0.68%) and lower homogeneity index (-1.13 ± 2.34).</p><p><strong>Conclusions: </strong>The results demonstrated that robustly optimized IMPT plans created by the KBPP model are of high quality and are comparable to expert plans. Furthermore, the KBPP model can generate more-robust and more-homogenous plans compared with those of expert plans. More studies need to be done for the validation of the proton KBPP model at more-complicated treatment sites.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 2","pages":"62-72"},"PeriodicalIF":1.7,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8489488/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39669115","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":"An Introduction to the International Journal of Particle Therapy's Special Issue on Particle Therapy for Head and Neck Malignancies","authors":"S. Frank","doi":"10.14338/2331-5180-8.1.1","DOIUrl":"https://doi.org/10.14338/2331-5180-8.1.1","url":null,"abstract":"Particle therapy has emerged as a standard-of-care treatment option in the management of head and neck malignancies owing to its unique physical and biologic properties that lead to improved clinical outcomes. Likewise, the value of particle therapy in the management of head and neck tumors has rapidly evolved over the past decade, and head and neck cancer management currently represents one of the most common indications for the use of proton therapy. It is therefore my privilege to introduce this special IJPT Particle Therapy for Head and Neck Malignancies issue, which offers 33 articles by renowned international authors knowledgeable in head and neck cancer management, making it, to date, the most definitive guide to this new standard of care. The research presented herein expands our knowledge of the biologic enhancement effect of proton therapy, the physical properties that require unique and complex treatment planning approaches, and the resulting improvement in long-term clinical outcomes. Further clarity has been provided on the use of advanced Monte Carlo and LET-based treatment planning and quality assurance methods for emerging treatment centers, thereby minimizing the risk of unnecessary side effects and complications. Additional opportunities are offered for personalization of particle therapy through combining its biologic enhancement effects with concurrent systemic therapy. From pediatrics to adults, the issue seeks to advance health policy and improve patient access with model-based selection, activity-based costing, cost-effectiveness, financial toxicity, and work productivity outcomes. I would like to dedicate this special issue to our head and neck cancer patients worldwide who have participated in the clinical trials and research protocols that have resulted in these publications, thereby advancing our knowledge and standard of care for future patients. like dedicate this special issue to my parents and family, who have constant support to see this project to completion.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 1","pages":"1 - 2"},"PeriodicalIF":1.7,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42493929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NRG Oncology Survey of Monte Carlo Dose Calculation Use in US Proton Therapy Centers.","authors":"Liyong Lin,&nbsp;Paige A Taylor,&nbsp;Jiajian Shen,&nbsp;Jatinder Saini,&nbsp;Minglei Kang,&nbsp;Charles B Simone,&nbsp;Jeffrey D Bradley,&nbsp;Zuofeng Li,&nbsp;Ying Xiao","doi":"10.14338/IJPT-D-21-00004","DOIUrl":"https://doi.org/10.14338/IJPT-D-21-00004","url":null,"abstract":"<p><strong>Purpose/objectives: </strong>Monte Carlo (MC) dose calculation has appeared in primary commercial treatment-planning systems and various in-house platforms. Dual-energy computed tomography (DECT) and metal artifact reduction (MAR) techniques complement MC capabilities. However, no publications have yet reported how proton therapy centers implement these new technologies, and a national survey is required to determine the feasibility of including MC and companion techniques in cooperative group clinical trials.</p><p><strong>Materials/methods: </strong>A 9-question survey was designed to query key clinical parameters: scope of MC utilization, validation methods for heterogeneities, clinical site-specific imaging guidance, proton range uncertainties, and how implants are handled. A national survey was distributed to all 29 operational US proton therapy centers on 13 May 2019.</p><p><strong>Results: </strong>We received responses from 25 centers (86% participation). Commercial MC was most commonly used for primary plan optimization (16 centers) or primary dose evaluation (18 centers), while in-house MC was used more frequently for secondary dose evaluation (7 centers). Based on the survey, MC was used infrequently for gastrointestinal, genitourinary, gynecology and extremity compared with other more heterogeneous disease sites (<i>P</i> < .007). Although many centers had published DECT research, only 3/25 centers had implemented DECT clinically, either in the treatment-planning system or to override implant materials. Most centers (64%) treated patients with metal implants on a case-by-case basis, with a variety of methods reported. Twenty-four centers (96%) used MAR images and overrode the surrounding tissue artifacts; however, there was no consensus on how to determine metal dimension, materials density, or stopping powers.</p><p><strong>Conclusion: </strong>The use of MC for primary dose calculation and optimization was prevalent and, therefore, likely feasible for clinical trials. There was consensus to use MAR and override tissues surrounding metals but no consensus about how to use DECT and MAR for human tissues and implants. Development and standardization of these advanced technologies are strongly encouraged for vendors and clinical physicists.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 2","pages":"73-81"},"PeriodicalIF":1.7,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8489489/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39669116","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":"Intensity-Modulated Proton Therapy for Nasopharynx Cancer: 2-year Outcomes from a Single Institution.","authors":"Vonetta M Williams,&nbsp;Upendra Parvathaneni,&nbsp;George E Laramore,&nbsp;Saif Aljabab,&nbsp;Tony P Wong,&nbsp;Jay J Liao","doi":"10.14338/IJPT-20-00057.1","DOIUrl":"https://doi.org/10.14338/IJPT-20-00057.1","url":null,"abstract":"<p><strong>Purpose: </strong>Advances in radiotherapy have improved tumor control and reduced toxicity in the management of nasopharyngeal carcinoma (NPC). Local failure remains a problem for some patients with advanced primary tumors, and toxicities are significant given the large treatment volume and tumor proximity to critical structures, even with modern photon-based radiotherapy. Proton therapy has unique dosimetric advantages, and recent technological advances now allow delivery of intensity-modulated proton therapy (IMPT), which can potentially improve the therapeutic ratio in NPC. We report our 2-year clinical outcomes with IMPT for NPC.</p><p><strong>Materials and methods: </strong>We retrospectively reviewed treatment records of patients with NPC treated with IMPT at our center. Demographics, dosimetry, tumor response, local regional control (LRC), distant metastasis, overall survival, and acute and late toxicity outcomes were reviewed. Analyses were performed with descriptive statistics and Kaplan-Meier method. Toxicity was graded per Common Terminology Criteria for Adverse Events (version 4.0).</p><p><strong>Results: </strong>Twenty-six patients were treated from 2015 to 2020. Median age was 48 years (range, 19-73 years), 62% (n = 16) had T3-T4 disease, 92% (n = 24) were node positive, 92% (n = 24) had stage III-IV disease, and 69% (n = 18) had positive results for Epstein-Barr virus. Dose-painted pencil-beam IMPT was used. Most patients (85%; 22 of 26) were treated with 70 Gy(RBE) in 33 fractions once daily; 4 (15%) underwent hyperfractionated accelerated treatment twice daily. All received concurrent cisplatin chemotherapy; 7 (27%) also received induction chemotherapy. All patients (100%) completed the planned radiotherapy, and no acute or late grade 4 or 5 toxicities were observed. At median follow-up of 25 months (range, 4-60), there were 2 local regional failures (8%) and 3 distant metastases (12%). The Kaplan-Meier 2-year LRC, freedom from distant metastasis, and overall survival were 92%, 87%, and 85% respectively.</p><p><strong>Conclusion: </strong>IMPT is feasible in locally advanced NPC with early outcomes demonstrating excellent LRC and favorable toxicity profile. Our data add to the growing body of evidence supporting the clinical use of IMPT for NPC.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"8 2","pages":"28-40"},"PeriodicalIF":1.7,"publicationDate":"2021-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8489486/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39580491","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}