International Journal of Particle Therapy最新文献

{"title":"Strategic Operational Redesign Improves Prior Authorization Access: A Validation Study.","authors":"Eric D Brooks, Fantine Giap, Vincent Cassidy, Matthew S Ning, Bradlee Robbert, Polly Redding, Matthew Palmer, L Montreal Turner, William M Mendenhall, Stuart Klein, Nancy P Mendenhall","doi":"10.14338/IJPT-23-00009.1","DOIUrl":"10.14338/IJPT-23-00009.1","url":null,"abstract":"<p><strong>Purpose: </strong>Obtaining prior authorization (PA) before treatment is becoming increasingly burdensome in oncology, especially in radiation oncology. Here, we describe the impact of a strategic novel operational PA redesign to shorten authorization time and to improve patient access to cancer care at a large United States academic proton therapy center. We ask whether such a redesign may be replicable and adoptable across oncology centers.</p><p><strong>Materials and methods: </strong>Our PA redesign strategy was based on a 3-tiered approach. Specifically, we (1) held payors accountable to legally backed timelines, (2) leveraged expertise on insurance policies and practices, and (3) updated the submission, appeal writing, and planning procedures for PA. Metrics were compared at the following 3 time points: 6 months before, at phase-in, and at 6 months after intervention.</p><p><strong>Results: </strong>In analyzing the impact of improving PA access to care, the percentage of approvals for commercial proton beam therapy improved by an absolute 30.6% postintervention (<i>P</i> < .001). The proportion of commercially insured patients treated with proton beam therapy also increased by 6.2%, and the number of new starts rose by 11.7 patients/mo. Overall patient census increased by 13 patients/d. Median authorization time was 1 week, and 90% of surveyed providers reported reduced PA burden and improved patient care.</p><p><strong>Conclusion: </strong>This is the first validated, comprehensive operational strategy to improve access to cancer therapy while reducing the burden of PA. This novel approach may be helpful for addressing barriers to PA in medical and surgical oncology because the redesign is predicated on laws that regulate PA across disciplines.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"1 1","pages":"65-72"},"PeriodicalIF":1.7,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10698628/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44242671","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-Specific Quality Assurance in Pencil Beam Scanning by 2-Dimensional Array","authors":"Nuttida Rawiwan, Nichakan Chatchumnan, Mananchaya Vimolnoch, Sakda Kingkaew, Sornjarod Oonsiri","doi":"10.14338/ijpt-23-00016.1","DOIUrl":"https://doi.org/10.14338/ijpt-23-00016.1","url":null,"abstract":"Purpose: This study aimed to determine the characteristics of 2D ionization chamber array and the confidence limits of the gamma passing rate in pencil beam scanning proton therapy. Materials and Methods: The Varian ProBeam Compact spot-scanning system and the PTW OCTAVIUS 1500XDR array were used as a proton therapy system and detector, respectively. Our methods consisted of 2 parts: (1) the characteristics of the detector were tested and (2) patient-specific quality assurance was performed and evaluated by gamma analysis using dose-difference and distance-to-agreement criteria of 3% and 2 mm, respectively, with 123 treatment plans in head and neck, breast, chest, abdomen, and pelvic regions. Results: The PTW OCTAVIUS 1500XDR array had good reproducibility, uniformity, linearity, repetition rate, and monitor unit per spot within 0.1%, with accuracy, energy dependence, and measurement depth within 0.5%. The overall uncertainty of the PTW OCTAVIUS 1500XDR array was 2.49%. For field size and range shifter, using gamma analysis, the passing rate was 100%. The overall results of patient-specific quality assurance with the gamma evaluation were 98.9% ± 1.6% in 123 plans and confidence limit was 95.7%. Conclusion: The PTW OTAVIUS 1500XDR offered effective performance in pencil beam scanning proton therapy.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":" 35","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135341094","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":"Advancing the Role of Proton Therapy for Spine Metastases Through Diagnostic Scan–Based Planning","authors":"Cameron W. Swanick, Michael H. Shang, Kevin Erhart, Jonathan Cabrera, James Burkavage, Tomas Dvorak, Naren Ramakrishna, Zhiqiu Li, Amish Shah, Sanford L. Meeks, Omar A. Zeidan, Patrick Kelly","doi":"10.14338/ijpt-23-00005.1","DOIUrl":"https://doi.org/10.14338/ijpt-23-00005.1","url":null,"abstract":"Abstract Purpose: Many patients with metastatic cancer live years beyond diagnosis, and there remains a need to improve the therapeutic ratio of metastasis-directed radiation for these patients. This study aimed to assess a process for delivering cost-effective palliative proton therapy to the spine using diagnostic scan–based planning (DSBP) and prefabricated treatment delivery devices. Materials and Methods: We designed and characterized a reusable proton aperture system that adjusts to multiple lengths for spine treatment. Next, we retrospectively identified 10 patients scan treated with thoracic proton therapy who also had a diagnostic computed tomography within 4 months of simulation. We contoured a T6-T9 target volume on both the diagnostic scans (DS) and simulation scans (SS). Using the aperture system, we generated proton plans on the DS using a posterior–anterior beam with no custom range compensator to treat T6-T9 to 8 Gy × 1. Plans were transferred to the SS to compare coverage and normal tissue doses, followed by robustness analysis. Finally, we compared normal tissue doses and costs between proton and photon plans. Results were compared using the Wilcoxon signed-rank test. Results: Median D95% on the DS plans was 101% (range, 100%–102%) of the prescription dose. Median Dmax was 107% (range, 105%–108%). When transferred to SS, coverage and hot spots remained acceptable for all cases. Heart and esophagus doses did not vary between the DS and SS proton plans (P &amp;gt;.2). Robustness analysis with 5 mm X/Y/Z shifts showed acceptable coverage (D95% &amp;gt; 98%) for all cases. Compared with the proton plans, the mean heart dose was higher for both anterior–posterior/posterior–anterior and volumetric modulated arc therapy plans (P &amp;lt; .01). Cost for proton DSBP was comparable to more commonly used photon regimens. Conclusion: Proton DSBP is technically feasible and robust, with superior sparing of the heart compared with photons. Eliminating simulation and custom devices increases the value of this approach in carefully selected patients.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":" 91","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135340491","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":"Proceedings to the 61st Annual Conference of the Particle Therapy Cooperative Group","authors":"","doi":"10.14338/ijpt-23-ptcog61-10.2","DOIUrl":"https://doi.org/10.14338/ijpt-23-ptcog61-10.2","url":null,"abstract":"","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"76 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135868300","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":"Novel Monthly Quality Assurance Regimen and 5-Year Analysis Using a Proton Metrology System","authors":"Ozgur Ates, Jackie Faught, Fakhriddin Pirlepesov, David Sobczak, Chia-ho Hua, Thomas E. Merchant","doi":"10.14338/ijpt-23-00004.1","DOIUrl":"https://doi.org/10.14338/ijpt-23-00004.1","url":null,"abstract":"Purpose To develop a novel, monthly quality assurance (QA) regimen for a proton therapy system that uses 2 custom phantoms, each housing a commercial scintillator detector and a charge-coupled device camera. The novel metrology system assessed QA trends at a pediatric proton therapy center from 2018 to 2022. Materials and Methods The measurement system was designed to accommodate horizontal and vertical positioning of the commercial device and to enable gantry and couch isocentricity measurements (using a star shot procedure), proton spot profile verification, and imaging and radiation congruence tests to be performed simultaneously in the dual-phantom setup. Gantry angles and proton beam energies were varied and alternated each month, using gantry angles of 0°, 30°, 60°, 90°, 120°, 150°, and 180° and discrete beam energies of 69.4, 84.5, 100, 139.1, 180.4, 200.4, and 221.3 MeV after radiographic verification. A total of 1176 individual monthly QA measurements of gantry and couch isocentricity, spot size, and congruence were analyzed. Results Gantry and couch star shot measurements showed beam isocentricities of 0.3 ± 0.2 mm and 0.2 ± 0.2 mm, respectively, which were within the threshold of 1.0 mm. Spot sizes for each discrete energy were within the threshold of ± 10% of the baseline values for all 3 proton rooms. The imaging and radiation coincidence test results for the 1176 individual monthly QA measurements were 0.5 mm for the 50th percentile and 1.2 mm (the clinical threshold) for the 97.6th percentile. Conclusions Integrating a commercial device with custom phantoms improved the quality of proton system checks compared with previous methods using radiochromic films, loose ball bearings, and foam. The scheme of alternating beam angles with discrete energies in the monthly QA-enabled, clinically meaningful verification of beam energy and gantry angle combinations while the machine performance and accuracy were being checked.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105606","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":"Proton Therapy in the Treatment of Men with Breast Cancer","authors":"Julie A. Bradley, Jayden Gracie, Raymond B. Mailhot Vega, Eric D. Brooks, Tenna Burchianti, Oluwadamilola T. Oladeru, Xiaoying Liang, Nancy P. Mendenhall","doi":"10.14338/ijpt-23-00007.1","DOIUrl":"https://doi.org/10.14338/ijpt-23-00007.1","url":null,"abstract":"Abstract Purpose Male breast cancer treatment involves multimodality therapy, including radiation therapy; nevertheless, few men have received proton therapy (PT) for it. Further, heart disease is an established leading cause of death in men, and radiation therapy heart dose correlates with cardiac toxicity, highlighting the need for cardiac-sparing radiation techniques. Thus, we provide a descriptive analysis of PT in a male breast cancer cohort. Patients and Methods Men who received PT for localized breast cancer between 2012 and 2022 were identified from a prospective database. Toxicities were prospectively recorded by using the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0. Results Five male patients were identified. All had estrogen receptor (ER)–positive, Her2neu-negative disease and received adjuvant endocrine therapy. One had genetic testing positive for BRCA2, one had a variant of unknown significance (VUS) in the APC gene, and one had a VUS in MSH2. Median age was 73 years (range, 41–80). Baseline comorbidities included obesity (n = 1), diabetes (n = 1), hypertension (n = 4), history of deep vein thrombosis (n = 1), personal history of myocardial infarction (n = 3; 1 with a pacemaker), and a history of lung cancer (n = 1). All received PT to the left chest wall and comprehensive regional lymphatics. One received passive-scattering PT, and 4 received pencil beam scanning. One patient received a boost to the mastectomy incision via electrons. Median heart dose was 1 GyRBE (range, 0–1.0), median 0.1-cm3 dose to the left anterior descending artery was 7.5 GyRBE (range, 0–14.2), and median follow-up was 2 years (range, 0.75–6.5); no patient experienced a new cardiac event, and all remain free from breast cancer recurrence and progression. Conclusion In a small case series for a rare diagnosis, PT to the chest wall and regional lymphatics, including internal mammary nodes, resulted in low cardiac exposure, high local regional disease control rates, and minimal toxicity. Proton therapy should be considered for treating men with breast cancer to achieve cardiac sparing.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"18 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134972610","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":"Pencil Beam Scanning Proton Therapy for Adolescents and Young Adults with Head and Neck Sarcomas","authors":"Miriam Vázquez, Katja Baust, Amaia Ilundain, Dominic Leiser, Barbara Bachtiary, Alessia Pica, Ulrike L. Kliebsch, Gabriele Calaminus, Damien C. Weber","doi":"10.14338/ijpt-23-00010.1","DOIUrl":"https://doi.org/10.14338/ijpt-23-00010.1","url":null,"abstract":"Abstract Purpose To assess clinical outcomes of adolescents and young adults (AYAs) with head and neck sarcomas (HNSs) treated with pencil beam scanning proton therapy (PBSPT) and to report quality of life (QoL). Materials and Methods Twenty-eight AYAs (aged 15 to 39 years) with HNS treated between January 2001 and July 2022 at our institution were included. The median age was 21.6 years. Rhabdomyosarcoma (39.3%), Ewing sarcoma (17.9%), chondrosarcoma (14.3%), and osteosarcoma (14.3%) were the most frequent diagnoses. Three (10.7%) patients were metastatic before PBSPT and 13 (46.4%) patients had a tumor with intracranial extension. The median total radiation dose was 63 GyRBE (range, 45 to 74 GyRBE). Thirteen (46.4%) patients received concomitant chemotherapy. Toxicity was reported according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0 (US National Institutes of Health, Bethesda, Maryland). Survival was estimated using the Kaplan-Meier method. QoL was assessed using a PEDQOL (Pediatric Quality of Life Questionnaire) questionnaire. Self-reported outcomes were assessed using institutional questionnaires. Results With a median follow-up of 57 months (range, 3.7 to 243 months), 5 patients (17.8%) had local failure (LF) only, 2 (7.1%) experienced distant failure (DF) only, and 2 (7.1%) had LF and DF. The estimated 5-year local control (LC) and distant control (DC) rates were 71.8% and 80.5%, respectively. The median times to LF and DF were 13.4 and 22.2 months, respectively. Four (14.3%) patients died, all but one from their HNS. Estimated 5-year overall survival was 90.7%. Six (21.4%) patients developed nonocular grade ≥3 toxicity, which consisted of otitis media (n = 2), hearing impairment (n = 2), osteoradionecrosis (n = 1), and sinusitis (n = 1). Four (14.3%) patients developed cataracts that required surgery. The 5-year freedom from nonocular grade 3 toxicity was 91.1%. No grade 4 or higher toxicity was observed. Adolescents rated their quality of life before treatment worse than their parents did. Conclusion Excellent outcomes with acceptable late-toxicity rates were observed for AYAs with HNS after PBSPT.","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"11 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134972773","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":"Cognition and Brain System Segregation in Pediatric Brain Tumor Patients Treated with Proton Therapy.","authors":"Anna V Dowling, Benjamin A Seitzman, Timothy J Mitchell, Michael Olufawo, Donna L Dierker, Hari Anandarajah, Ally Dworetsky, Alana McMichael, Catherine Jiang, Dennis L Barbour, Bradley L Schlaggar, David D Limbrick, Jennifer M Strahle, Joshua B Rubin, Joshua S Shimony, Stephanie M Perkins","doi":"10.14338/IJPT-22-00039.1","DOIUrl":"10.14338/IJPT-22-00039.1","url":null,"abstract":"<p><strong>Purpose: </strong>Pediatric brain tumor patients often experience significant cognitive sequelae. Resting-state functional MRI (rsfMRI) provides a measure of brain network organization, and we hypothesize that pediatric brain tumor patients treated with proton therapy will demonstrate abnormal brain network architecture related to cognitive outcome and radiation dosimetry.</p><p><strong>Participants and methods: </strong>Pediatric brain tumor patients treated with proton therapy were enrolled on a prospective study of cognitive assessment using the NIH Toolbox Cognitive Domain. rsfMRI was obtained in participants able to complete unsedated MRI. Brain system segregation (BSS), a measure of brain network architecture, was calculated for the whole brain, the high-level cognition association systems, and the sensory-motor systems.</p><p><strong>Results: </strong>Twenty-six participants were enrolled in the study for cognitive assessment, and 18 completed rsfMRI. There were baseline cognitive deficits in attention and inhibition and processing speed prior to radiation with worsening performance over time in multiple domains. Average BSS across the whole brain was significantly decreased in participants compared with healthy controls (1.089 and 1.101, respectively; <i>P</i> = 0.001). Average segregation of association systems was significantly lower in participants than in controls (<i>P</i> < 0.001) while there was no difference in the sensory motor networks (<i>P</i> = 0.70). Right hippocampus dose was associated with worse attention and inhibition (<i>P</i> < 0.05) and decreased segregation in the dorsal attention network (<i>P</i> < 0.05).</p><p><strong>Conclusion: </strong>Higher mean dose to the right hippocampus correlated with worse dorsal attention network segregation and worse attention and inhibition cognitive performance. Patients demonstrated alterations in brain network organization of association systems measured with rsfMRI; however, somatosensory system segregation was no different from healthy children. Further work with preradiation rsfMRI is needed to assess the effects of surgery and presence of a tumor on brain network architecture.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"10 1","pages":"32-42"},"PeriodicalIF":1.7,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10563667/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41215074","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":"Analysis of Performance and Failure Modes of the IROC Proton Liver Phantom.","authors":"Hunter Mehrens, Paige Taylor, Paola Alvarez, Stephen Kry","doi":"10.14338/IJPT-22-00043.1","DOIUrl":"10.14338/IJPT-22-00043.1","url":null,"abstract":"<p><strong>Purpose: </strong>To analyze trends in institutional performance and failure modes for the Imaging and Radiation Oncology Core's (IROC's) proton liver phantom.</p><p><strong>Materials and methods: </strong>Results of 66 phantom irradiations from 28 institutions between 2015 and 2020 were retrospectively analyzed. Univariate analysis and random forest models were used to associate irradiation conditions with phantom results. Phantom results included pass/fail classification, average thermoluminescent dosimeter (TLD) ratio of both targets, and percentage of pixels passing gamma of both targets. The following categories were evaluated in terms of how they predicted these outcomes: irradiation year, treatment planning system (TPS), TPS algorithm, treatment machine, number of irradiations, treatment technique, motion management technique, number of isocenters, and superior-inferior extent (in cm) of the 90% TPS isodose line for primary target 1 (PTV1) and primary target 2 (PTV2). In addition, failures were categorized by failure mode.</p><p><strong>Results: </strong>Average pass rate was approximately 52% and average TLD ratio for both targets had slightly improved. As the treatment field increased to cover the target, the pass rate statistically significantly fell. Lower pass rates were observed for Mevion machines, scattered irradiation techniques, and gating and internal target volume (ITV) motion management techniques. Overall, the accuracy of the random forest modeling of the phantom results was approximately 73% ± 14%. The most important predictor was the superior-inferior extent for both targets and irradiation year. Three failure modes dominated the failures of the phantom: (1) systematic underdosing, (2) poor localization in the superior-inferior direction, and (3) range error. Only 44% of failures have similar failure modes between the 2 targets.</p><p><strong>Conclusion: </strong>Improvement of the proton liver phantom has been observed; however, the pass rate remains the lowest among all IROC phantoms. Through various analysis techniques, range uncertainty, motion management, and underdosing are the main culprits of failures of the proton liver phantom. Clinically, careful consideration of the influences of liver proton therapy is needed to improve phantom performance and patient outcome.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"10 1","pages":"23-31"},"PeriodicalIF":1.7,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10563664/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41215072","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":"Case-Matched Outcomes of Proton Beam and Intensity-Modulated Radiation Therapy for Localized Prostate Cancer.","authors":"Alicia Bao,&nbsp;Andrew R Barsky,&nbsp;Stefan Both,&nbsp;John P Christodouleas,&nbsp;Curtiland Deville,&nbsp;Zelig A Tochner,&nbsp;Neha Vapiwala,&nbsp;Russell Maxwell","doi":"10.14338/IJPT-23-00002.1","DOIUrl":"10.14338/IJPT-23-00002.1","url":null,"abstract":"<p><strong>Purpose: </strong>Although both intensity-modulated radiation therapy (IMRT) and proton beam therapy (PBT) offer effective long-term disease control for localized prostate cancer (PCa), there are limited data directly comparing the 2 modalities.</p><p><strong>Methods: </strong>The data from 334 patients treated with conventionally fractionated (79.2 GyRBE in 44 fractions) PBT or IMRT were retrospectively analyzed. Propensity score matching was used to balance factors associated with biochemical failure-free survival (BFFS). Age, race, and comorbidities (not BFFS associates) remained imbalanced after matching. Univariable and covariate-adjusted multivariable (MVA) Cox regression models were used to determine if modality affected BFFS.</p><p><strong>Results: </strong>Of 334 patients, 176 (52.7%) were included in the matched cohort with exact matching to National Comprehensive Cancer Network (NCCN) risk group. With a median follow-up time of 9.0 years (interquartile range [IQR]: 7.8-10.2 years), long-term BFFS was similar between the IMRT and PBT matched arms with 8-year estimates of 85% (95% CI: 76%-91%) and 91% (95% CI: 82%-96%, <i>P</i> = .39), respectively. On MVA, modality was not significantly associated with BFFS in both the unmatched (hazard ratio [HR] = 0.75, 95% CI: 0.35-1.63, <i>P</i> = .47) and matched (HR = 0.87, 95% CI: 0.33-2.33, <i>P</i> = .78) cohorts. Prostate cancer-specific survival (PCSS) and overall survival (OS) were also similar (<i>P</i> > .05). However, in an unmatched analysis, the PBT arm had significantly fewer incidences of secondary cancers within the irradiated field (0.6%, 95% CI: 0.0%-3.1% versus 4.5%, 95% CI: 1.8%-9.0%, <i>P</i> = .028).</p><p><strong>Conclusions: </strong>Both PBT and IMRT offer excellent long-term disease control for PCa, with no significant differences between the 2 modalities in BFFS, PCSS, and OS in matched patients. In the unmatched cohort, fewer incidences of secondary malignancy were noted in the PBT group; however, owing to overall low incidence of secondary cancer and imbalanced patient characteristics between the 2 groups, these data are strictly hypothesis generating and require further investigation.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"10 1","pages":"1-12"},"PeriodicalIF":1.7,"publicationDate":"2023-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10563661/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41215073","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}