Dose-averaged linear energy transfer per se does not correlate with late rectal complications in carbon-ion radiotherapy
Dose-averaged linear energy transfer per se does not correlate with late rectal complications in carbon-ion radiotherapy
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DOI：
10.1016/j.radonc.2020.08.029
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发表时间：
2020-12-01
影响因子：
5.7
通讯作者：
Tsuji, Hiroshi
中科院分区：
文献类型：
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作者：
Okonogi, Noriyuki;Matsumoto, Shinnosuke;Tsuji, Hiroshi
背景和目的：多项研究重点关注增加肿瘤内的线性能量转移（LET），以在碳离子放射治疗（C-ion RT）中实现更高的生物学效应。然而，目前尚不清楚 LET 是否会影响晚期并发症。我们评估了物理剂量和 LET 分布是否可能是 C 离子放疗中晚期直肠并发症的特定因素。材料和方法：总体而言，对 134 例子宫癌患者进行了登记和回顾性分析。在 134 名患者中，有 132 名接受了超过 6 个月的随访。评估基于 Kanai 模型的相对生物有效性 (RBE) 加权剂量（表面上的“临床剂量”）、平均剂量 LET (LETd) 或物理剂量与直肠并发症之间的相关性。直肠并发症根据放射治疗肿瘤学组/欧洲癌症研究和治疗组织标准进行分级。结果：9 名患者出现 3 级或 4 级晚期直肠并发症。线性回归分析发现，临床剂量中的D-2cc是>= 3级晚期直肠并发症的唯一危险因素（p = 0.012）。接受者操作特征分析发现，60.2 Gy (RBE) 的 D-2cc 是预测 >= 3 级晚期直肠并发症的合适截止值。在 35 例直肠 D-2cc ≥ 60.2 Gy (RBE) 的患者中，未发现严重直肠毒性与单独 LETd 或物理剂量本身之间存在相关性。 结论：我们证明，严重直肠毒性与 C 离子 RT 临床剂量的直肠 D-2cc 相关。然而，没有发现严重直肠毒性与单独的 LETd 或物理剂量本身之间存在相关性。 (C) 2020 作者。由 Elsevier B.V. 出版
Background and purpose: Several studies have focused on increasing the linear energy transfer (LET) within tumours to achieve higher biological effects in carbon-ion radiotherapy (C-ion RT). However, it remains unclear whether LET affects late complications. We assessed whether physical dose and LET distribution can be specific factors for late rectal complications in C-ion RT.Materials and methods: Overall, 134 patients with uterine carcinomas were registered and retrospectively analysed. Of 134 patients, 132 who were followed up for >6 months were enrolled. The correlations between the relative biological effectiveness (RBE)-weighted dose based on the Kanai model (the ostensible "clinical dose"), dose-averaged LET (LETd), or physical dose and rectal complications were evaluated. Rectal complications were graded according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria.Results: Nine patients developed grade 3 or 4 late rectal complications. Linear regression analysis found that D-2cc in clinical dose was the sole risk factor for >= grade 3 late rectal complications (p = 0.012). The receiver operating characteristic analysis found that D-2cc of 60.2 Gy (RBE) was a suitable cut-off value for predicting >= grade 3 late rectal complications. Among 35 patients whose rectal D-2cc was >= 60.2 Gy (RBE), no correlations were found between severe rectal toxicities and LETd alone or physical dose per se.Conclusion: We demonstrated that severe rectal toxicities were related to the rectal D-2cc of the clinical dose in C-ion RT. However, no correlations were found between severe rectal toxicities and LETd alone or physical dose per se. (C) 2020 The Author(s). Published by Elsevier B.V.