International Journal of Particle Therapy最新文献

{"title":"Machine Learning-Based Beam Delivery Time Model for Mevion S250i With Hyperscan Technology.","authors":"Giorgio Cartechini, Francesco Giuseppe Cordoni, Mirko Unipan, Ilaria Rinaldi","doi":"10.1016/j.ijpt.2026.101301","DOIUrl":"10.1016/j.ijpt.2026.101301","url":null,"abstract":"<p><strong>Purpose: </strong>Accurate prediction of beam delivery time (BDT) is critical for operational efficiency, 4D dose calculations, and advanced proton therapy techniques. Despite its importance, no machine-specific BDT model exists for Mevion systems.</p><p><strong>Methods: </strong>We developed the first machine learning-based model for the Mevion S250i Hyperscan system. Institutional machine log files from 11 patients (1120 machine log files) were used to extract features describing spot position, energy layer changes, Adaptive Aperture (AA) movements, and spot charge. Inter-pulse time ( <math><mrow><mi>Δ</mi> <mi>T</mi></mrow> </math> ) served as the target variable. A Random Forest model was trained with cross-validation and tested on held-out data. SHAP (SHapley Additive exPlanations) analysis quantified feature contributions.</p><p><strong>Results: </strong>The model achieved mean absolute errors (MAE) ranging from 0.9 ms for short intervals ( <math><mo><</mo></math> 50 ms) to 211 ms for long delays ( <math><mo>></mo></math> 1000 ms). AA movements were the dominant global predictor for <math><mrow><mi>Δ</mi> <mi>T</mi> <mo>></mo> <mn>50</mn></mrow> </math> ms, whereas spot positions and pulse charge dominated short intervals. Energy changes had a minor global influence but locally contributed to a large <math><mrow><mi>Δ</mi> <mi>T</mi></mrow> </math> , consistent with range modulator physics. The model was tested on two clinically relevant applications: volumetric repainting beam sequence and 4D dose recalculation for interplay evaluation. The predicted cumulative delivery times deviated by only -1.6% from machine log files, and dosimetric metrics ( <math> <msub><mrow><mi>D</mi></mrow> <mrow><mn>98</mn></mrow> </msub> </math> , <math> <msub><mrow><mi>D</mi></mrow> <mrow><mn>95</mn></mrow> </msub> </math> , and <math> <msub><mrow><mi>V</mi></mrow> <mrow><mn>95</mn></mrow> </msub> </math> ) remained within intrinsic delivery variability.</p><p><strong>Conclusions: </strong>This study presents the first machine learning-based BDT model for the Mevion S250i system, accurately capturing both predictive performance and machine-specific temporal dynamics. Explainable AI analysis using SHAP provided detailed insights into the operational characteristics of the system, highlighting the contributions of energy layer switching, AA adjustments, and spot position shifts to delivery time. The proposed BDT model demonstrated strong predictive performance across the clinical applications evaluated, supporting its potential use for interplay assessment, 4D dose calculation, and delivery time-based plan optimization.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"19 ","pages":"101301"},"PeriodicalIF":2.0,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12924178/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147272249","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":"Spread-Out Bragg Peak FLASH Radiotherapy for Head and Neck Reirradiation: A Treatment Planning Study.","authors":"Marc Alomar, Arnaud Pin, Rasmus Nilsson, Erik Traneus, Gregory N Gan, Hao Gao, Yuting Lin","doi":"10.1016/j.ijpt.2026.101302","DOIUrl":"10.1016/j.ijpt.2026.101302","url":null,"abstract":"<p><strong>Purpose: </strong>Proton FLASH radiotherapy offers the potential to enhance normal tissue sparing while maintaining tumor control. This study investigates the dosimetric advantages of spread-out Bragg peak (SOBP) FLASH compared to standard intensity modulated proton therapy (IMPT) for re-irradiation in recurrent head-and-neck (HN) cancer.</p><p><strong>Methods: </strong>Eight recurrent HN cancer cases were retrospectively analyzed using hypofractionated proton therapy plans (5 × 8 Gy fractions). FLASH plans were designed using a single energy layer and patient-specific modulation devices implemented in the RayStation. Robust optimizations accounted for setup (±3 mm) and range (±3.5%) uncertainties. A biologically effective dose model incorporating a FLASH-modifying factor (FMF) of 0.7 for normal tissues meeting dose (≥5 Gy) and dose rate (≥40 Gy/s) thresholds was used to assess the therapeutic potential of FLASH. Dosimetric parameters such as target coverage, homogeneity index (HI), conformity index (CI), and organ-at-risk (OAR) sparing were compared between FLASH and standard IMPT plans.</p><p><strong>Results: </strong>Compared to standard IMPT, SOBP-based FLASH plans demonstrated reduced target homogeneity (<i>p</i> < .05) and slightly lower dose conformity, with the effects more pronounced for targets near the neck region due to larger center-to-axis distances to avoid collisions. Despite these limitations, FLASH plans maintained robust target coverage (D95% > 96.6% ± 1.2%) in robustness scenarios. The FLASH effective dose model indicated a reduction in the maximum dose to OARs within 2 cm of the target volume; for instance, the maximum dose to the larynx decreased from 29.9 Gy (IMPT) to 25.4 Gy (FLASH).</p><p><strong>Conclusions: </strong>SOBP-based FLASH plans preserved the dosimetric advantages of IMPT for sparing distal normal tissues while offering potential reductions in high-dose exposure to OARs near the target volume. Incorporating an FMF of 0.7, these plans showed comparable dosimetric profiles to IMPT with the added benefit of enhanced normal tissue protection under uncertainty, a unique advantage over conventional radiotherapy.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"19 ","pages":"101302"},"PeriodicalIF":2.0,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12914863/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228886","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":"PTCOG Ocular Survey - Perspective on Ocular Particle Therapy: Current Practices and Emerging Trends.","authors":"Linda Mortimer, Roelf Slopsema, Alejandro Mazal, Jan-Willem Beenakker, Rémi Dendale, Andrea Denker, Emmanuelle Fleury, Anais Groulier, Andrzej Kacperek, Kavita K Mishra, Jatinder Saini, Alexei V Trofimov, Juliette Thariat, Petra Trnková, Marie Vidal, Helen A Shih, Jan Hrbacek, Jens Heufelder","doi":"10.1016/j.ijpt.2026.101300","DOIUrl":"10.1016/j.ijpt.2026.101300","url":null,"abstract":"<p><strong>Purpose: </strong>To overview the status and trends in the current rapidly evolving field of ocular particle therapy (OPT).</p><p><strong>Materials and methods: </strong>The Particle Therapy Co-Operative Group Ocular Subcommittee developed an online survey, including 127 questions, made available to treatment centers worldwide, between April 2022 and January 2024. The survey covered a broad range of topics from general program organization and beamline description, to diagnoses and patient numbers treated, treatment planning and set-up, quality assurance techniques, as well as insights into anticipated future developments.</p><p><strong>Results: </strong>Twenty facilities offered OPT by the end of 2023: 3 in Asia, 9 in Europe, and 8 in the USA. Combined, they treated, on average, 1800 patients per year, with uveal melanoma being the most common indication. The vast majority of treatments continue to be delivered on dedicated horizontal beamlines, both high (>120 Mev) and low (<75 MeV) energy. Five of the 7 recently established programs (n = 7, since 2015) use high-energy general-purpose beamlines, where some beam characteristics, including penumbrae size and dose delivery rate, differ from those typically achieved on dedicated beamlines. The evolution of the ocular treatment framework is ongoing as 9 centers reported the intent to upgrade their systems within five years, to engage state-of-the-art developments in beam delivery, imaging, and planning tools.</p><p><strong>Conclusion: </strong>Common protocols in dosimetry, dose, and fractionation have largely been adopted worldwide, while variability persists in planning, quality assurance, and delivery workflows. The obsolescence of dedicated ocular proton systems and key planning tools, and a lack of standardization, remain as pressing challenges. The adoption of non-dedicated high-energy systems on gantries and integration into multipurpose treatment environments enhances OPT accessibility, but this transition requires ongoing critical evaluation of dosimetric trade-offs and clinical outcomes. Multicenter collaboration, technological innovation, and clinical validation are essential to continued assurance of the safe and effective delivery of OPT worldwide.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"19 ","pages":"101300"},"PeriodicalIF":2.0,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12914457/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146228906","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 Use of Protons in the Management of Recurrent, Previously Irradiated Adenoid Cystic Carcinoma.","authors":"Irini Yacoub, Achraf Shamseddine, Daniel Kallini, Nader Mohamed, Kaveh Zakeri, Yao Yu, Linda Chen, Daphna Gelblum, Sean McBride, Nadeem Riaz, Eric Sherman, Richard J Wong, Marc Cohen, Loren Scott Michel, Ian Ganly, Lara Dunn, Alan Ho, Zhigang Zhang, Nicolas Toumbacaris, Nancy Y Lee","doi":"10.1016/j.ijpt.2025.101296","DOIUrl":"10.1016/j.ijpt.2025.101296","url":null,"abstract":"<p><strong>Introduction: </strong>Adenoid cystic carcinoma (ACC) of the head and neck is a rare malignancy with a high risk of perineural invasion, local recurrence, and distant metastasis. Recurrent ACC poses unique challenges due to its aggressive nature, resection limited by morbidity, and prior radiation. Proton therapy, with its ability to spare normal tissues via the Bragg peak, may offer a promising and safe re-irradiation approach, especially in patients not amenable to resection requiring high definitive doses. The purpose of this study was to evaluate outcomes of patients with recurrent ACC treated with proton radiation.</p><p><strong>Methods: </strong>We reviewed the records of all patients with recurrent head and neck ACC treated with proton therapy between November 2012 and December 2023. This cohort included patients with both resected and unresected disease. Standard imaging, including MRI for perineural spread and PET for distant recurrence, was used in all cases. Descriptive statistics were used to analyze patient, tumor, and treatment characteristics, and the Kaplan-Meier method and cumulative incidence curves were utilized to estimate overall survival (OS) and loco-regional recurrence (LRR), respectively.</p><p><strong>Results: </strong>A total of 19 patients were included, with 6 (32%) receiving adjuvant re-irradiation and 13 (68%) receiving definitive proton re-irradiation. Median dose in the adjuvant group was 63.36 (59.40-70.07), and 59.20 (14.80-70.00) in the primary RT group. The median OS for all patients was 62% at 24 months and 48% at 48 months. Patients receiving adjuvant therapy had an OS of 80% at 24 and 48 months, while those not receiving surgery had an OS of 52% and 31% at 24- and 48-months. LRR at 24 months was 11% for all patients. No grade 5 toxicities were observed.</p><p><strong>Conclusion: </strong>This study demonstrates the feasibility and potential benefits of proton re-irradiation for recurrent ACC, with promising local-regional control and minimal toxicity.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"19 ","pages":"101296"},"PeriodicalIF":2.0,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12859797/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146107569","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":"Terminology Proposal for Adaptive Particle Therapy Classification and Strategies.","authors":"Pieter Populaire, Rita Simoes, Lena Nenoff, Petra Trnkova, Lorenzo Placidi, Kristin Stützer, Eva van Weerd, Francesca Albertini","doi":"10.1016/j.ijpt.2025.101293","DOIUrl":"10.1016/j.ijpt.2025.101293","url":null,"abstract":"","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"19 ","pages":"101293"},"PeriodicalIF":2.0,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12819340/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146031074","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":"\"Hadrontherapy for Life\" Symposium, Caen, March 10/11, 2025-Strategy for the Future-Pediatric Tumors.","authors":"Jean-Louis Habrand, Semi B Harrabi, Shigeru Yamada, Zheng Wang, Siamak Haghdoost, Ellie Light, Tatsuya Ohno, Jerôme Doyen, Remi Dendale, Jacques Balosso, Audrey Larnaudie, Anthony Vela, Arnold Pompos, Bradford Hoppe, Anita Mahajan, Juliette Thariat","doi":"10.1016/j.ijpt.2025.101286","DOIUrl":"10.1016/j.ijpt.2025.101286","url":null,"abstract":"<p><p>The symposium \"Hadrontherapy for life,\" held in Caen, on March 10 and 11, 2025, brought together over 100 international experts of heavy ions particle therapy. Clinical aspects of current indications and future strategies were discussed. If protontherapy remains the cornerstone of current strategies dealing with pediatric malignancies, in order to better spare normal tissues from deleterious effects of radiation, heavier ions such as carbon ions could play a role in selected highly radio-resistant processes such as bone and non rhabdomyosrcomas soft tissue sarcomas. A special mention should be made to helium ions tested since 2021 in Europe that mimic protons with further ballistic selectivity. If immediate and early side effects of heavy ions look modest, long-term tolerance still needs to be carefully evaluated, including risks of carcinogenesis.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"18 ","pages":"101286"},"PeriodicalIF":2.0,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12721058/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145820950","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":"\"Hadrontherapy for Life\" Symposium, Caen, March 10/11, 2025-Strategy for the Future-Pancreatic Cancer.","authors":"Jean-Louis Habrand, Siamak Haghdoost, Semi B Harrabi, Cindy Neuzillet, Véronique Vendrely, Ellie Light, Jean Lubrano, Tatsuya Ohno, Shigeru Yamada, Zheng Wang, Jerôme Doyen, Remi Dendale, Dinu Stefan, Anita Mahajan, Bradford Hoppe, Arnold Pompos, Juliette Thariat","doi":"10.1016/j.ijpt.2025.101287","DOIUrl":"10.1016/j.ijpt.2025.101287","url":null,"abstract":"<p><p>The symposium \"Hadrontherapy for Life,\" held in Caen, on February 10 and 11, 2025, brought together over 100 international experts of heavy ions particle therapy. Clinical aspects of current indications and future strategies were discussed. Pancreatic cancer that may reach the second cause of cancer mortality in the next decade, was prioritized. Stimulating clinical data accumulated in Japan and more recently in Europe suggest an important role for carbon ion radiotherapy (CIRT) in advanced presentations but also in a preoperative setting, at the price of acceptable toxicity. Biological aspects also plead for combinations of CIRT with bio or immune therapy.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"18 ","pages":"101287"},"PeriodicalIF":2.0,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12721308/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145820953","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":"Feasibility and efficacy of hypofractionated proton reirradiation for recurrent lung cancer.","authors":"Jerome M Karp, Kara M Banson, Oren Cahlon, Henry K Tsai, Jae Y Lee, Sherry X Yan, Heba Darwish, Kevin Sine, Dennis Mah, Brian H Chon, Benjamin T Cooper","doi":"10.1016/j.ijpt.2025.101213","DOIUrl":"10.1016/j.ijpt.2025.101213","url":null,"abstract":"<p><strong>Purpose: </strong>The goal of this study is to report the feasibility and outcomes of hypofractionated proton reirradiation in patients with recurrent thoracic tumors.</p><p><strong>Materials and methods: </strong>Data were retrospectively collected for patients who received hypofractionated proton therapy for recurrent lung cancer at a single facility. Proton reirradiation was delivered using a total of 15 fractions. Patient and tumor characteristics, adverse events, and dose-volume histogram parameters were collected and analyzed descriptively. Tumor control and patient survival were analyzed using Kaplan-Meier statistics. Univariate logistic regression was performed to analyze the relationship between dose-volume histogram parameters and acute and late toxicity.</p><p><strong>Results: </strong>Thirty-one patients who received thoracic proton reirradiation were included. The median patient age was 71.4. Most patients (77.4%) were treated to a total of 60 Gy (RBE) in 15 fractions and had tumors smaller than 50 cc (64.5%). The median interval between the 2 radiation courses was 21.3 months (2.9-227.1). Twenty-one out of 31 plans (67.7%) successfully reached a target PTV coverage with V95% > 95%. Complete prior plan dosimetric information was available for 19 out of 31 plans. The median value of the equivalent dose in 2 Gy (RBE) fractions (EQD2) from the plan sum for the lung V20 Gy (RBE) was 24.9%, and for the V5 Gy (RBE) was 44.8%. The median follow-up was 9.0 months. One-year local, regional, and distant control were 92.3% (95% CI 78.9-100), 71.1% (95% CI 52.1-97.0), and 80.6% (95% CI 64.6-100), respectively. Only two patients experienced grade 3 or higher acute or late toxicities. Acute esophagitis was associated with the esophagus Dmax (<i>P</i> = .031) and Dmean (<i>P</i> = .041).</p><p><strong>Conclusion: </strong>This study demonstrates the feasibility and efficacy of a hypofractionated course of proton reirradiation for recurrent thoracic tumors.</p><p><strong>Data availability: </strong>The data that support the findings of this study are available on request from the corresponding author.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"18 ","pages":"101213"},"PeriodicalIF":2.0,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12721071/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145821004","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":"Relative Biological Effectiveness-Clinical Practice at US Proton Therapy Centers.","authors":"Armin Lühr, Radhe Mohan, Anita Mahajan, Helen A Shih, Harald Paganetti","doi":"10.1016/j.ijpt.2025.101212","DOIUrl":"10.1016/j.ijpt.2025.101212","url":null,"abstract":"<p><strong>Purpose: </strong>Proton therapy, with its high conformality and superior dose distribution, is becoming an increasingly prevalent modality in radiation oncology. Although a generic relative biological effectiveness (RBE) value of 1.1 for treatment planning has been adopted, evidence suggests that RBE varies with dose, linear energy transfer (LET), and biological endpoints. This variation raises concerns about underestimating the RBE-weighted dose, which may significantly impact treatment outcomes. To assess the awareness and management of RBE variability in clinical practice, we conducted a survey among US proton therapy centers.</p><p><strong>Materials and methods: </strong>The survey consisted of 32 questions grouped into subtopics, such as awareness of RBE variability, practices to account for variability, and future needs. It was distributed among 29 centers through the auspices of the Particle Therapy Co-Operative Group - North America.</p><p><strong>Results: </strong>The response rate was 80% and revealed significant apprehension about the assumption of a constant RBE. All respondents used a fixed RBE of 1.1, yet expressed varying degrees of concern about its appropriateness. Most centers report unanticipated toxicities and local recurrences potentially linked to an underestimation of RBE, highlighting the need for revisiting current practices. The survey indicated that nearly all centers consider RBE variability during beam arrangement, and some perform LET and variable RBE calculations for patient-specific treatments. There is a strong consensus on the need for multi-institutional databases, studies to accumulate clinical evidence, and education on proton RBE to better understand RBE's clinical implications.</p><p><strong>Conclusions: </strong>This study is an overview of current clinical practices regarding proton RBE and identifies key priorities for future research. Although deviations from the generic RBE of 1.1 is commonly considered in treatment planning, the absence of standardized approaches leads to inconsistencies. Developing consensus guidelines and integrating advanced RBE and LET-based models into treatment planning could improve the precision and safety of proton therapy.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"18 ","pages":"101212"},"PeriodicalIF":2.0,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12686715/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145726171","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":"Connecting Visual Perception With Proton Therapy-Induced Optic Damage Using Archetypal Analysis.","authors":"Thao-Nguyen Pham, Thibaud Mathis, Nathan Azemar, Mathieu Seraphim, Cyril Moignier, Jean-Claude Quintyn, Juliette Thariat","doi":"10.1016/j.ijpt.2025.101211","DOIUrl":"10.1016/j.ijpt.2025.101211","url":null,"abstract":"<p><strong>Purpose: </strong>Radiotherapy can lead to radiation-induced optic neuropathy, with vision loss and visual field deficits related to localized damage to the optic pathways. Accurately quantifying visual field deficits and establishing their spatial relationship with anatomical structures and radiation dose distribution remains a significant challenge. We applied archetypal analysis of visual fields as a novel artificial intelligence approach in oncology to identify distinct, interpretable patterns of visual field loss and to model their spatial evolution over time after pencil beam scanning proton therapy.</p><p><strong>Methods: </strong>Machine learning of standardized automated static visual field perimetry was used to decompose the high-dimensional visual field data into convex combinations of representative visual loss patterns, that is, visual archetypes, at both the eye and patient levels. Associations between archetype proportions and radiation dose metrics were evaluated using linear regression, stratified by baseline visual field to account for pre-existing deficits.</p><p><strong>Results: </strong>In 236 patients, 7 archetypal patterns of visual field loss were identified, including tunnel vision, temporal hemianopia, and diffuse full-field loss. More severe patterns were more frequently observed in patients with meningiomas and pituitary adenomas. Longitudinal analysis revealed an annual reduction of 1.9% in the normal visual field archetype in patients with no-to-mild baseline deficits and 9.7% in those with moderate deficits. Dose-archetype associations were clinically significant after adjusting for baseline deficits. Each 1 Gy increase in minimum chiasm dose was associated with a 0.2% decrease in the normal vision archetype.</p><p><strong>Conclusion: </strong>This is the first application of archetypal analysis for predicting radiation-induced optic neuropathy. It enables spatially grounded reconnection between patient perception and radiation damage along optic pathways. This approach offers new mechanistic insights into optic pathway injury towards voxel-level correlation between radiation dose and functional loss and supports data-driven personalization of radiotherapy.</p>","PeriodicalId":36923,"journal":{"name":"International Journal of Particle Therapy","volume":"18 ","pages":"101211"},"PeriodicalIF":2.0,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12741418/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145850874","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}