Jarey H Wang, Ryan Oglesby, Anh Tran, Melike Guryildirim, Mattea Miller, Khadija Sheikh, Heng Li, Matthew Ladra, William T Hrinivich, Sahaja Acharya
{"title":"铅笔束扫描质子治疗小儿后窝肿瘤后线性能量传递和剂量与辐射坏死的关系:剂量和线性能量传输与辐射坏死的关系","authors":"Jarey H Wang, Ryan Oglesby, Anh Tran, Melike Guryildirim, Mattea Miller, Khadija Sheikh, Heng Li, Matthew Ladra, William T Hrinivich, Sahaja Acharya","doi":"10.1016/j.ijrobp.2024.11.086","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>Proton therapy is the preferred treatment modality for most pediatric central nervous system tumors. The risk of radiation necrosis may be increased at the distal end of the beam because of an increase in linear energy transfer (LET) and relative biological effectiveness (RBE) dose. We report on the association of LET and dose with radiation necrosis after pencil beam scanning proton therapy in pediatric posterior fossa tumors using a case-control framework.</p><p><strong>Materials and methods: </strong>From 2019 to 2022, 33 patients less than or equal to 18 years of age treated with first-line proton therapy for primary tumors in the posterior fossa and with 6 or more months of follow-up magnetic resonance imaging were retrospectively identified. Nine patients with imaging changes consistent with necrosis were matched with controls in a 1:2 fashion based on age, sex, dose, and follow-up time from proton therapy. Dose (Gy [RBE]) and dose-averaged LET (LETd) values for target structures and organs at risk were computed and compared between cases and controls.</p><p><strong>Results: </strong>Within the whole cohort, the mean age was 6.6 years (SD, 4.77) with a median follow-up time of 24.1 months. Within the case-control matched cohort (18 controls and 9 cases), there were no significant differences in age, sex, time to follow-up, tumor location, dose, and use of concurrent chemotherapy. The mean time to necrotic imaging finding was 4.47 months (SD, 2.03). Cases demonstrated significantly higher brainstem D50 (P = .02). LETd was not different between cases and controls. However, when using a combined metric of higher brainstem dose {>47.5 (Gy [RBE])} and higher LETd (>3.5 keV/µm), a greater proportion of cases compared with controls met this metric (89% vs 39%, P = .02).</p><p><strong>Conclusions: </strong>Combined effects of intermediate-to-high dose and LETd in the brainstem may contribute to greater necrosis risk after pencil beam scanning proton therapy in children with posterior fossa tumors.</p>","PeriodicalId":14215,"journal":{"name":"International Journal of Radiation Oncology Biology Physics","volume":" ","pages":""},"PeriodicalIF":6.4000,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The Association of Linear Energy Transfer and Dose With Radiation Necrosis After Pencil Beam Scanning Proton Therapy in Pediatric Posterior Fossa Tumors.\",\"authors\":\"Jarey H Wang, Ryan Oglesby, Anh Tran, Melike Guryildirim, Mattea Miller, Khadija Sheikh, Heng Li, Matthew Ladra, William T Hrinivich, Sahaja Acharya\",\"doi\":\"10.1016/j.ijrobp.2024.11.086\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Purpose: </strong>Proton therapy is the preferred treatment modality for most pediatric central nervous system tumors. The risk of radiation necrosis may be increased at the distal end of the beam because of an increase in linear energy transfer (LET) and relative biological effectiveness (RBE) dose. We report on the association of LET and dose with radiation necrosis after pencil beam scanning proton therapy in pediatric posterior fossa tumors using a case-control framework.</p><p><strong>Materials and methods: </strong>From 2019 to 2022, 33 patients less than or equal to 18 years of age treated with first-line proton therapy for primary tumors in the posterior fossa and with 6 or more months of follow-up magnetic resonance imaging were retrospectively identified. Nine patients with imaging changes consistent with necrosis were matched with controls in a 1:2 fashion based on age, sex, dose, and follow-up time from proton therapy. Dose (Gy [RBE]) and dose-averaged LET (LETd) values for target structures and organs at risk were computed and compared between cases and controls.</p><p><strong>Results: </strong>Within the whole cohort, the mean age was 6.6 years (SD, 4.77) with a median follow-up time of 24.1 months. Within the case-control matched cohort (18 controls and 9 cases), there were no significant differences in age, sex, time to follow-up, tumor location, dose, and use of concurrent chemotherapy. The mean time to necrotic imaging finding was 4.47 months (SD, 2.03). Cases demonstrated significantly higher brainstem D50 (P = .02). LETd was not different between cases and controls. However, when using a combined metric of higher brainstem dose {>47.5 (Gy [RBE])} and higher LETd (>3.5 keV/µm), a greater proportion of cases compared with controls met this metric (89% vs 39%, P = .02).</p><p><strong>Conclusions: </strong>Combined effects of intermediate-to-high dose and LETd in the brainstem may contribute to greater necrosis risk after pencil beam scanning proton therapy in children with posterior fossa tumors.</p>\",\"PeriodicalId\":14215,\"journal\":{\"name\":\"International Journal of Radiation Oncology Biology Physics\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":6.4000,\"publicationDate\":\"2024-11-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Radiation Oncology Biology Physics\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1016/j.ijrobp.2024.11.086\",\"RegionNum\":1,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ONCOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Radiation Oncology Biology Physics","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.ijrobp.2024.11.086","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ONCOLOGY","Score":null,"Total":0}
The Association of Linear Energy Transfer and Dose With Radiation Necrosis After Pencil Beam Scanning Proton Therapy in Pediatric Posterior Fossa Tumors.
Purpose: Proton therapy is the preferred treatment modality for most pediatric central nervous system tumors. The risk of radiation necrosis may be increased at the distal end of the beam because of an increase in linear energy transfer (LET) and relative biological effectiveness (RBE) dose. We report on the association of LET and dose with radiation necrosis after pencil beam scanning proton therapy in pediatric posterior fossa tumors using a case-control framework.
Materials and methods: From 2019 to 2022, 33 patients less than or equal to 18 years of age treated with first-line proton therapy for primary tumors in the posterior fossa and with 6 or more months of follow-up magnetic resonance imaging were retrospectively identified. Nine patients with imaging changes consistent with necrosis were matched with controls in a 1:2 fashion based on age, sex, dose, and follow-up time from proton therapy. Dose (Gy [RBE]) and dose-averaged LET (LETd) values for target structures and organs at risk were computed and compared between cases and controls.
Results: Within the whole cohort, the mean age was 6.6 years (SD, 4.77) with a median follow-up time of 24.1 months. Within the case-control matched cohort (18 controls and 9 cases), there were no significant differences in age, sex, time to follow-up, tumor location, dose, and use of concurrent chemotherapy. The mean time to necrotic imaging finding was 4.47 months (SD, 2.03). Cases demonstrated significantly higher brainstem D50 (P = .02). LETd was not different between cases and controls. However, when using a combined metric of higher brainstem dose {>47.5 (Gy [RBE])} and higher LETd (>3.5 keV/µm), a greater proportion of cases compared with controls met this metric (89% vs 39%, P = .02).
Conclusions: Combined effects of intermediate-to-high dose and LETd in the brainstem may contribute to greater necrosis risk after pencil beam scanning proton therapy in children with posterior fossa tumors.
期刊介绍:
International Journal of Radiation Oncology • Biology • Physics (IJROBP), known in the field as the Red Journal, publishes original laboratory and clinical investigations related to radiation oncology, radiation biology, medical physics, and both education and health policy as it relates to the field.
This journal has a particular interest in original contributions of the following types: prospective clinical trials, outcomes research, and large database interrogation. In addition, it seeks reports of high-impact innovations in single or combined modality treatment, tumor sensitization, normal tissue protection (including both precision avoidance and pharmacologic means), brachytherapy, particle irradiation, and cancer imaging. Technical advances related to dosimetry and conformal radiation treatment planning are of interest, as are basic science studies investigating tumor physiology and the molecular biology underlying cancer and normal tissue radiation response.