International Journal of Particle Therapy最新文献

{"title":"Estimating Potential Benefits to Neurocognition with Proton Therapy in Adults with Brain Tumors.","authors":"Mariana Petruccelli,&nbsp;Amy Parent,&nbsp;Michael Holwell,&nbsp;Hitesh Dama,&nbsp;Grace Tsui,&nbsp;Zhihui Amy Liu,&nbsp;Derek S Tsang","doi":"10.14338/IJPT-22-00024.1","DOIUrl":"https://doi.org/10.14338/IJPT-22-00024.1","url":null,"abstract":"<p><strong>Purpose: </strong>Photon radiation therapy (RT) is important in the treatment of many brain tumors but can negatively affect neurocognition. Proton therapy (PT) can reduce doses to normal brain structures. We compared photon and proton plans to estimate the potential benefit in cognition if the patient were treated with PT.</p><p><strong>Materials and methods: </strong>We analyzed 23 adult patients with proton and photon plans for the treatment of a primary brain tumor. Cognitive outcomes were predicted using converted equivalent dose (EQD2) with an α/β ratio of 3 to left temporal lobe and normal brain tissue. Risks of cognitive decline on 2 specific tests, the Controlled Oral Word Association Test (COWAT [letter S], a test of verbal fluency) and the Wechler Adult Intelligence Scale (WAIS-IV Coding Test, a test of processing speed) were derived from a previously published model.</p><p><strong>Results: </strong>Dose reductions to left temporal lobe and normal brain tissue translated into lower estimated probabilities of impairment in specific neurocognitive test scores after PT. With a mean dose reduction from 1490 to 1092 cGy in EQD2 to the left temporal lobe (<i>P</i> < .001), there was reduction in probability of impairment in the COWAT (Letter S) test from 6.8% to 5.4%. Similar results were seen with the normal brain (750 to 451 cGy in EQD2, <i>P</i> < .001), with reduction in probability of impairment in the WAIS-IV Coding test from 5% to 4.1%. Other structures experiencing dose reduction with PT included each cochlea, posterior fossa, each temporal lobe, and each hippocampus.</p><p><strong>Conclusion: </strong>We confirmed an association between PT and lower doses to brain substructures, which is expected to result in a modest decrease in probability of impairment in neurocognitive test scoring. These findings should be confirmed in prospective cohorts of patients treated with PT.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 4","pages":"261-268"},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10166017/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9453384","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":"Radiation Therapy for Primary Adenoid Cystic Carcinoma of the Trachea: Photons, Protons, or Carbon.","authors":"Alexander J Tun,&nbsp;Bradford S Hoppe,&nbsp;Yujie Zhao,&nbsp;Ian Makey,&nbsp;Sebastian Fernandez-Bussy,&nbsp;Xiaoying Liang","doi":"10.14338/IJPT-22-00036.1","DOIUrl":"https://doi.org/10.14338/IJPT-22-00036.1","url":null,"abstract":"<p><p>Primary adenoid cystic carcinoma of the trachea (ACC-T) is an extremely rare cancer of the central bronchial system. It is usually associated with an excellent prognosis. Surgery is the standard treatment for resectable tumors, while radiation therapy is used for unresectable tumors or medically inoperable patients. Radiation therapy can be delivered with photons, protons, or carbon ion therapy. In this report, we review a case of unresectable ACC-T in a middle-aged female patient who was treated with radiation therapy and review the potential benefits of the different types of radiation therapy.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 4","pages":"302-305"},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10166014/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9823945","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":"Factors Associated With Travel Distance in the Receipt of Proton Breast Radiation Therapy.","authors":"Sylvia S Rhodes,&nbsp;Eva Berlin,&nbsp;Nikhil Yegya-Raman,&nbsp;Abigail Doucette,&nbsp;Michelle Gentile,&nbsp;Gary M Freedman,&nbsp;Neil K Taunk","doi":"10.14338/IJPT-22-00018.1","DOIUrl":"https://doi.org/10.14338/IJPT-22-00018.1","url":null,"abstract":"<p><strong>Introduction: </strong>Proton radiation therapy (PBT) may reduce cardiac doses in breast cancer treatment. Limited availability of proton facilities could require significant travel distances. This study assessed factors associated with travel distances for breast PBT.</p><p><strong>Materials and methods: </strong>Patients receiving breast PBT at the University of Pennsylvania from 2010 to 2021 were identified. Demographic, cancer, and treatment characteristics were summarized. Straight-line travel distances from the department to patients' addresses were calculated using BatchGeo. Median and mean travel distances were reported. Given non-normality of distribution of travel distances, Wilcoxon rank sum or Kruskal-Wallis test was used to determine whether travel distances differed by race, clinical trial participation, disease laterality, recurrence, and prior radiation.</p><p><strong>Results: </strong>Of 1 male and 284 female patients, 67.8% were White and 21.7% Black. Median travel distance was 13.5 miles with interquartile range of 6.1 to 24.8 miles, and mean travel distance was 13.5 miles with standard deviation of 261.4 miles. 81.1% of patients traveled less than 30 and 6.0% more than 100 miles. Black patients' travel distances were significantly shorter than White patients' and non-Black or non-White patients' travel distances (median = 4.5, 16.5, and 11.3 miles, respectively; <i>P</i> < .0001). Patients not on clinical trials traveled more those on clinical trials (median = 14.7 and 10.2 miles, respectively; <i>P</i> = .032). There was no difference found between travel distances of patients with left-sided versus right-sided versus bilateral disease (<i>P</i> = .175), with versus without recurrent disease (<i>P</i> = .057), or with versus without prior radiation (<i>P</i> = .23).</p><p><strong>Conclusion: </strong>This study described travel distances and demographic and clinicopathologic characteristics of patients receiving breast PBT at the University of Pennsylvania. Black patients traveled less than White and non-Black or non-White patients and comprised a small portion of the cohort, suggesting barriers to travel and PBT. Patients did not travel further to receive PBT for left-sided or recurrent disease.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 3","pages":"1-9"},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9875828/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10602296","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":"Incidence of Rib Fracture following Treatment with Proton Therapy for Breast Cancer.","authors":"Julie A Bradley,&nbsp;Xiaoying Liang,&nbsp;Raymond B Mailhot Vega,&nbsp;Chunbo Liu,&nbsp;Eric D Brooks,&nbsp;Teena Burchianti,&nbsp;Emma Viviers,&nbsp;Roi Dagan,&nbsp;Oluwadamilola T Oladeru,&nbsp;Christopher G Morris,&nbsp;Nancy P Mendenhall","doi":"10.14338/IJPT-22-00034.1","DOIUrl":"https://doi.org/10.14338/IJPT-22-00034.1","url":null,"abstract":"<p><strong>Purpose: </strong>To determine the rib fracture rate in a cohort of patients with breast cancer treated with proton therapy.</p><p><strong>Patient and methods: </strong>From a prospective database, we identified 225 patients treated with proton therapy between 2012 and 2020 (223 women; 2 men). Clinical and dosimetric data were extracted, the cumulative incidence method assessed rib fracture rate, and Fine-Gray tests assessed prognostic significance of select variables. In-field rib fracture was defined as a fracture that occurred in a rib located within the 10% isodose line. Out-of-field rib fracture was defined as a fracture occurring in a rib location outside of the 10% isodose line.</p><p><strong>Results: </strong>Of the patients, 74% had left-sided breast cancer; 5%, bilateral; and 21%, right-sided. Dual-energy x-ray absorptiometry scans showed normality in 20%, osteopenia in 34%, and osteoporosis in 6% (test not performed in 40%). Additionally, 57% received an aromatase inhibitor. Target volumes were breast ± internal mammary nodes (IMNs) (16%), breast and comprehensive regional lymphatics (32%), chest wall ± IMNs (1%), and chest wall/comprehensive regional lymphatics (51%). Passive-scattered proton therapy was used for 41% of patients, 58% underwent pencil-beam scanning (PBS), and 1% underwent a combination (passive scattering/PBS), with 85% of patients receiving a boost. Median follow-up was 3.1 years, with 97% having >12-month follow-up. The 3-year cumulative in-field rib fracture incidence was 3.7%. Eight patients developed in-field rib fractures (1 symptomatic, 7 imaging identified) for a 0.4% symptomatic rib fracture rate. Median time from radiation completion to rib fracture identification was 1.8 years (fractures were identified within 2.2 years for 7 of 8 patients). No variables were associated with rib fracture on univariate analysis. Three fractures developed outside the radiation field (0.9% cumulative incidence of out-of-field rib fracture).</p><p><strong>Conclusion: </strong>In this series of patients with breast cancer treated with proton therapy, the 3-year rib fracture rates remain low (in-field 3.7%; symptomatic 0.4%). As in photon therapy, the asymptomatic rate may be underestimated owing to a lack of routine surveillance imaging. However, patients experiencing symptomatic rib fractures after proton therapy for breast cancer are rare.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 4","pages":"269-278"},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10166011/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9823948","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 With Concurrent Chemotherapy for Thoracic Esophageal Cancer: Toxicity, Disease Control, and Survival Outcomes.","authors":"Michael S Rutenberg,&nbsp;Bradford S Hoppe,&nbsp;Jason S Starr,&nbsp;Ziad Awad,&nbsp;Mathew Thomas,&nbsp;Christopher G Morris,&nbsp;Perry Johnson,&nbsp;Randal H Henderson,&nbsp;Jeremy C Jones,&nbsp;Bharatsinh Gharia,&nbsp;Steven Bowers,&nbsp;Herbert C Wolfsen,&nbsp;Sunil Krishnan,&nbsp;Stephen J Ko,&nbsp;Hani M Babiker,&nbsp;Romaine C Nichols","doi":"10.14338/IJPT-22-00021.1","DOIUrl":"https://doi.org/10.14338/IJPT-22-00021.1","url":null,"abstract":"<p><strong>Purpose: </strong>When treating esophageal cancer with radiation therapy, it is critical to limit the dose to surrounding structures, such as the lung and/or heart, as much as possible. Proton radiation therapy allows a reduced radiation dose to both the heart and lungs, potentially reducing the risk of cardiopulmonary toxicity. Here, we report disease control, survival, and toxicity outcomes among patients with esophageal cancer treated with proton radiation therapy and concurrent chemotherapy (chemoradiation therapy; CRT) with or without surgery.</p><p><strong>Materials and methods: </strong>We enrolled 17 patients with thoracic esophageal carcinoma on a prospective registry between 2010 and 2021. Patients received proton therapy to a median dose of 50.4-GyRBE (range, 50.4-64.8) in 1.8-Gy fractions.Acute and late toxicities were graded per the Common Terminology Criteria for Adverse Events, version 4.0 (US National Cancer Institute, Bethesda, Maryland). In addition, disease control, patterns of failure, and survival outcomes were collected.</p><p><strong>Results: </strong>Nine patients received preoperative CRT, and 8 received definitive CRT. Overall, 88% of patients had adenocarcinoma, and 12% had squamous cell carcinoma. With a median follow-up of 2.1 years (range, 0.5-9.4), the 3-year local progression-free, disease-free, and overall survival rates were 85%, 66%, and 55%, respectively. Two patients (1 with adenocarcinoma and 1 with squamous cell carcinoma) recurred at the primary site after refusing surgery after a complete clinical response to CRT. The most common acute nonhematologic and hematologic toxicities, respectively, were grades 1 to 3 esophagitis and grades 1 to 4 leukopenia, both affecting 82% of patients. No acute cardiopulmonary toxicities were observed in the absence of surgical resection. Reagarding surgical complications, 3 postoperative cardiopulmonary complications occurred as follows: 1 grade 1 pleural effusion, 1 grade 3 pleural effusion, and 1 grade 2 anastomotic leak. Two severe late CRT toxicities occurred: 1 grade 5 tracheoesophageal fistula and 1 grade 3 esophageal stenosis requiring a feeding tube.</p><p><strong>Conclusion: </strong>Proton radiation therapy is a safe, effective treatment for esophageal cancer with increasing evidence supporting its role in reducing cardiopulmonary toxicity.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 3","pages":"18-29"},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9875824/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10602292","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":"Fast and Furious: Fast Neutron Therapy in Cancer Treatment.","authors":"Konstantin Gordon,&nbsp;Igor Gulidov,&nbsp;Timur Fatkhudinov,&nbsp;Sergey Koryakin,&nbsp;Andrey Kaprin","doi":"10.14338/IJPT-22-00017","DOIUrl":"https://doi.org/10.14338/IJPT-22-00017","url":null,"abstract":"<p><p>Fast neutron therapy has been used for decades. In conjunction with recent advances in photonic techniques, fast neutrons are no longer of much oncologic interest, which is not unequivocally positive, given their undoubted therapeutic value. This mini-review recalls the history of medical research on fast neutrons, considers their physical and radiobiological properties alongside their benefits for cancer treatment, and discusses their place in modern radiation oncology.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 2","pages":"59-69"},"PeriodicalIF":1.7,"publicationDate":"2022-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9415749/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40348458","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":"Outcomes and Toxicities of Nonmedullary Thyroid Tumors Treated with Proton Beam Radiation Therapy.","authors":"Irini Youssef,&nbsp;Jennifer Yoon,&nbsp;Nader Mohamed,&nbsp;Kaveh Zakeri,&nbsp;Robert H Press,&nbsp;Yao Yu,&nbsp;Jung Julie Kang,&nbsp;Richard J Wong,&nbsp;R Michael Tuttle,&nbsp;Ashok Shaha,&nbsp;Eric Sherman,&nbsp;Nancy Y Lee","doi":"10.14338/IJPT-22-00005.1","DOIUrl":"10.14338/IJPT-22-00005.1","url":null,"abstract":"<p><strong>Purpose: </strong>Proton therapy is an emerging therapy for several malignancies owing to its favorable therapeutic ratio. There are very limited data on the use of proton therapy in the management of thyroid carcinoma. Our objective was to review the safety, feasibility, and outcomes of proton therapy for patients with thyroid cancer treated to the head and neck.</p><p><strong>Methods: </strong>From our institution's proton database from 2012 to 2021, we identified 22 patients with thyroid cancer treated with proton beam therapy. We evaluated outcomes and toxicities.</p><p><strong>Results: </strong>Median follow-up was 26 months. Of the 22 patients, 50% were female. The mean age was 65 years. Three patients had anaplastic cancer; 13, papillary carcinoma; 2, follicular carcinoma; and 2, poorly differentiated carcinoma. Forty-six percent had T4 disease. Primary targets were the central neck compartment, level VI, and upper mediastinum. Radiation dose was 60 GyRBE adjuvantly, and 70 GyRBE for gross disease (range, 6000-7600 GyRBE). Eight patients underwent upfront adjuvant radiation, and 3 received definitive radiation for unresectable disease upfront. Eleven patients received either salvage or palliative radiation. Fifty-nine percent of patients had extrathyroidal extension, and 64% of patients had gross disease in the neck before treatment. Fifty percent of patients had metastatic disease before treatment. Sixteen patients received concurrent chemotherapy, 63% of these patients received doxorubicin. For all patients, 1-year local regional recurrence (LRR) was 0%, and overall survival (OS) was 90%. Acute grade 3+ toxicities occurred in 27% of patients, the most frequent being dermatitis (27%). Three patients required a percutaneous endoscopic gastrostomy tube after radiation therapy (RT), 2 owing to progression. There were no grade 4+ toxicities.</p><p><strong>Conclusions: </strong>Proton therapy for thyroid cancer appears feasible and effective with minimal toxicities. Prospective studies comparing proton therapy with intensity-modulated RT, to evaluate the clinical efficacy of using proton therapy to reduce toxicities in patients undergoing radiation for thyroid cancer, are warranted.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 2","pages":"20-30"},"PeriodicalIF":1.7,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9415751/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40349606","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 Outcomes for Head and Neck Cutaneous Melanoma: Proton Collaborative Group Analysis.","authors":"James E Han, Alicia Lozano, Shaakir Hasan, J Isabelle Choi, Arpit M Chhabra, Henry Tsai, Nasiruddin Mohammed, Samir Patel, Sanford Katz, John H Chang, Charles B Simone, Robert H Press","doi":"10.14338/IJPT-22-00003.1","DOIUrl":"10.14338/IJPT-22-00003.1","url":null,"abstract":"<p><strong>Purpose: </strong>Reports of proton beam therapy (PBT) utilization for cutaneous melanoma of the head and neck (HN) region is virtually non-existent. This study reports on the efficacy and acute toxicities of PBT for primary HN cutaneous melanoma.</p><p><strong>Materials and methods: </strong>We queried the prospectively collected, multi-institutional Proton Collaborative Group registry for all consecutive patients with HN cutaneous melanoma receiving PBT from May 2010 to December 2019. Kaplan-Meier methods were used to estimate overall survival (OS), progression free survival (PFS), and local regional recurrence free survival (LRFS). Toxicity was reported per CTCAE version 4.0.</p><p><strong>Results: </strong>A total of 8 patients were identified with a median age of 69 (range, 37-88). All patients (100%) underwent surgery followed with postoperative PBT. There were 3 patients (37.5%) with T3 or T4 disease and 4 (50%) with N2 or N3 disease. The median radiation dose was 46 GyRBE (range, 27-70) and median dose per fraction was 2.4 GyRBE (range, 2.0-6.0) with the most common dose fractionation being 44 or 48 GyRBE in 20 fractions (n = 4). At a median follow-up of 40.1 months (range, 1.6-62.4) the 1 and 3 year OS rates were 85.7% and 35.7%, respectively. The median PFS was 25.40 months (95% CI, 2.53-58.70) while PFS at 1 year and 3 years was 85.7% and 35.7%, respectively. LRFS was 100% at 1 year and 85.7% at 3 years. Five of the 8 patients developed distant metastases, of which 3 received immunotherapy. Acute G2+ and G3+ toxicities occurred in 5 of 8 patients and 2 of 8 patients, respectively. G3 toxicities included radiation dermatitis (n = 1) and immunotherapy-related rash (n = 1). No G4+ toxicities were reported.</p><p><strong>Conclusion: </strong>Single modality PBT for HN melanomas in the definitive setting provides effective and durable local control rates with tolerable acute toxicity. Distant failure remains the primary pattern of failure.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 2","pages":"40-48"},"PeriodicalIF":2.1,"publicationDate":"2022-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9415747/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40348460","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":"Operational Performance of a Compact Proton Therapy System: A 5-Year Experience.","authors":"Omar A Zeidan,&nbsp;Ethan Pepmiller,&nbsp;Twyla Willoughby,&nbsp;Zhiqiu Li,&nbsp;James Burkavage,&nbsp;Brian Harper,&nbsp;Michael Fraser,&nbsp;Katie Moffatt,&nbsp;Sanford L Meeks,&nbsp;Naren Ramakrishna","doi":"10.14338/IJPT-21-00033.1","DOIUrl":"https://doi.org/10.14338/IJPT-21-00033.1","url":null,"abstract":"<p><strong>Purpose: </strong>We present an analysis of various operational metrics for a novel compact proton therapy system, including clinical case mix, subsystems utilization, and quality assurance trends in beam delivery parameters over a period of 5 years.</p><p><strong>Materials and methods: </strong>Patient-specific data from a total of 850 patients (25,567 fractions) have been collected and analyzed. The patient mix include a variety of simple, intermediate, and complex cases. Beam-specific delivery parameters for a total of 3585 beams were analyzed. In-room imaging system usage for off-line adaptive purpose is reported. We also report key machine performances metrics based on routine quality assurance in addition to uptime.</p><p><strong>Results: </strong>Our analysis shows that system subcomponents including gantry and patient positioning system have maintained a tight mechanical tolerance over the 5-year period. Various beam parameters were all within acceptable tolerances with no clear trends. Utilization frequency histograms of gantry and patient positioning system show that only a small fraction of all available angles was used for patient deliveries with cardinal angels as the most usable. Similarly, beam-specific metrics, such as range, modulation, and air gaps, were clustered unevenly over the available range indicating that this compact system was more than capable to treat the complex variety of tumors of our patient mix.</p><p><strong>Conclusion: </strong>Our data show that this compact system is versatile, robust, and capable of delivering complex treatments like a large full-gantry system. Utilization data show that a fraction of all subcomponents range of angular motion has been used. Compilation of beam-specific metrics, such as range and modulation, show uneven distributions with specific clustering over the entire usable range. Our findings could be used to further optimize the performance and cost-effectiveness of future compact proton systems.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 2","pages":"10-19"},"PeriodicalIF":1.7,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9415750/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40348461","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 Arc Therapy vs Interstitial HDR Brachytherapy in Gynecologic Cancer with Parametrial/pelvic Side Wall Extension.","authors":"ByongYong Yi,&nbsp;Sina Mossahebi,&nbsp;Arezoo Modiri,&nbsp;Elizabeth M Nichols,&nbsp;Mariana Guerrero,&nbsp;Narottam Lamichhane,&nbsp;Pranshu Mohindra","doi":"10.14338/IJPT-22-00013.1","DOIUrl":"https://doi.org/10.14338/IJPT-22-00013.1","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate whether volumetric-modulated proton arc therapy (VPAT) plans generate comparable doses to organs at risk (OARs) compared with interstitial high-dose-rate (iHDR) brachytherapy for patients with gynecologic cancer with disease extension to parametrial/pelvic side wall, who are not eligible for the aggressive procedure.</p><p><strong>Materials and methods: </strong>VPAT delivers proton arc beams by modulated energies at the beam nozzle while maintaining the same incident energy to the gantry during the arc rotation. Plans of 10 patients previously treated with iHDR brachytherapy for high-risk clinical treatment volumes (HRCTV; 31.8-110.6 cm³; lateral dimensions, 4.2-5.6 cm) were selected and compared with VPAT plans. VPAT plans for each patient were designed using a 152- to 245-MeV range of energy-modulated proton beams.</p><p><strong>Results: </strong>HRCTV coverage of the VPAT plans was comparable to that of the iHDR plans, with V150% showing no statistical differences. On average, the V100% and V90% of VPAT plans were higher than those of the iHDR plans, 95.0% vs 91.9% (<i>P</i> = .02) and 98.6% vs 97.5% (<i>P</i> = .02), respectively. D100 was also 17% higher for the VPAT plans (<i>P</i> = .03). On average, the D_2cm³ of bladder, rectum, and small bowels in the VPAT plans were considerably lower than those in iHDR plans (by 17.4%, 35.2%, and 65.6%, respectively; <i>P <</i> .05 for all OARs).</p><p><strong>Conclusion: </strong>VPAT-generated plans were dosimetrically superior to those with HDR brachytherapy with interstitial needles for locally advanced gynecologic cancer with parametrial/pelvic side wall disease extension. Dosimetrically, VPAT provides a noninvasive alternative to iHDR brachytherapy with a superior dosimetric profile.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"9 2","pages":"31-39"},"PeriodicalIF":1.7,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9415748/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40348459","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}