Uchinami Yusuke, Katoh Norio, Suzuki Ryusuke, Kanehira Takahiro, Tamura Masaya, Takao Seishin, Matsuura Taeko, Miyamoto Naoki, Fujita Yoshihiro, Koizumi Fuki, Taguchi Hiroshi, Yasuda Koichi, Nishioka Kentaro, Yokota Isao, Kobashi Keiji, Aoyama Hidefumi
Department of Radiation Oncology, Hokkaido University Faculty of Medicine, North 15 West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan.
Department of Medical Physics, Hokkaido University Hospital, North 14 West 5, Kita-ku, Sapporo, Hokkaido 060-8648, Japan.
Clin Transl Radiat Oncol. 2022 May 17;35:70-75. doi: 10.1016/j.ctro.2022.05.004. eCollection 2022 Jul.
For small primary liver tumors, favorable outcomes have been reported with both of proton beam therapy (PBT) and X-ray therapy (XRT). However, no clear criteria have been proposed in the cases for which and when of PBT or XRT has to be used. The aim of this study is to investigate cases that would benefit from PBT based on the predicted rate of hepatic toxicity.
Eligible patients were those who underwent PBT for primary liver tumors with a maximum diameter of ≤ 5 cm and Child-Pugh grade A (n = 40). To compare the PBT-plan, the treatment plan using volumetric modulated arc therapy was generated as the XRT-plan. The rate of predicted hepatic toxicity was estimated using five normal tissue complication probability (NTCP) models with three different endpoints. The differences in NTCP values (ΔNTCP) were calculated to determine the relative advantage of PBT. Factors predicting benefits of PBT were analyzed by logistic regression analysis.
From the dose-volume histogram comparisons, an advantage of PBT was found in sparing of the normal liver receiving low doses. The factors predicting the benefit of PBT differed depending on the selected NTCP model. From the five models, the total tumor diameter (sum of the target tumors), location (hepatic hilum vs other), and number of tumors (1 vs 2) were significant factors.
From the radiation-related hepatic toxicity, factors were identified to predict benefits of PBT in primary liver tumors with Child-Pugh grade A, with the maximum tumor diameter of ≤ 5 cm.
对于小型原发性肝肿瘤，质子束治疗（PBT）和X射线治疗（XRT）均已报告有良好的治疗效果。然而，对于何时以及何种情况下必须使用PBT或XRT，尚未提出明确的标准。本研究的目的是根据预测的肝毒性发生率，调查可能从PBT中获益的病例。
符合条件的患者为因最大直径≤5 cm的原发性肝肿瘤且Child-Pugh肝功能分级为A级而接受PBT治疗的患者（n = 40）。为了比较PBT计划，使用容积调强弧形治疗生成治疗计划作为XRT计划。使用具有三个不同终点的五种正常组织并发症概率（NTCP）模型估计预测的肝毒性发生率。计算NTCP值的差异（ΔNTCP）以确定PBT的相对优势。通过逻辑回归分析分析预测PBT获益的因素。
从剂量体积直方图比较中发现，PBT在低剂量正常肝脏的 sparing方面具有优势。预测PBT获益的因素因所选的NTCP模型而异。在这五个模型中，肿瘤总直径（靶肿瘤之和）、位置（肝门与其他部位）和肿瘤数量（1个与2个）是显著因素。
从与辐射相关的肝毒性方面，确定了一些因素来预测Child-Pugh肝功能分级为A级、最大肿瘤直径≤5 cm的原发性肝肿瘤中PBT的获益情况。
