Cao Yangsen, Zhu Xiaofei, Yu Chunshan, Jiang Lingong, Sun Yongjian, Guo Xueling, Zhang Huojun
Department of Radiation Oncology, Changhai Hospital Affiliated to Naval Medical University, Shanghai, China.
Front Oncol. 2023 Jan 30;12:1021058. doi: 10.3389/fonc.2022.1021058. eCollection 2022.
Re-irradiation of locally recurrent pancreatic cancer may be an optimal choice as a local ablative therapy. However, dose constraints of organs at risk (OARs) predictive of severe toxicity remain unknown. Therefore, we aim to calculate and identify accumulated dose distributions of OARs correlating with severe adverse effects and determine possible dose constraints regarding re-irradiation.
Patients receiving two courses of stereotactic body radiation therapy (SBRT) for the same irradiated regions (the primary tumors) due to local recurrence were included. All doses of the first and second plans were recalculated to an equivalent dose of 2 Gy per fraction (EQD). Deformable image registration with the workflow "Dose Accumulation-Deformable" of the MIM System (version: 6.6.8) was performed for dose summations. Dose-volume parameters predictive of grade 2 or more toxicities were identified, and the receiver operating characteristic (ROC) curve was used to determine optimal thresholds of dose constraints.
Forty patients were included in the analysis. Only the of the stomach [hazard ratio (HR): 1.02 (95% CI:1.00-1.04), P = 0.035] and of the intestine [HR: 1.78 (95% CI: 1.00-3.18), P = 0.049] correlated with grade 2 or more gastrointestinal toxicity. Hence, the equation of probability of such toxicity was Additionally, the area under the ROC curve and threshold of dose constraints of of the stomach and of the intestine were 0.779 and 77.575 cc, 0.769 and 4.22 Gy (α/β = 3), respectively. The area under the ROC curve of the equation was 0.821.
The of the stomach and of the intestine may be vital parameters to predict grade 2 or more gastrointestinal toxicity, of which the threshold of dose constraints may be beneficial for the practice of re-irradiation of locally relapsed pancreatic cancer.
对局部复发的胰腺癌进行再照射可能是一种局部消融治疗的最佳选择。然而，预测严重毒性的危及器官（OARs）的剂量限制尚不清楚。因此，我们旨在计算和识别与严重不良反应相关的OARs累积剂量分布，并确定再照射的可能剂量限制。
纳入因局部复发在相同照射区域（原发肿瘤）接受两程立体定向体部放疗（SBRT）的患者。将第一和第二计划的所有剂量重新计算为每分次2 Gy的等效剂量（EQD）。使用MIM系统（版本：6.6.8）的“剂量累积-可变形”工作流程进行可变形图像配准以进行剂量求和。确定预测2级或更高级别毒性的剂量体积参数，并使用受试者操作特征（ROC）曲线确定剂量限制的最佳阈值。
40例患者纳入分析。仅胃的[危险比（HR）：1.02（95%CI：1.00 - 1.04），P = 0.035]和小肠的[HR：1.78（95%CI：1.00 - 3.18），P = 0.049]与2级或更高级别的胃肠道毒性相关。因此，这种毒性的概率方程为此外，胃的和小肠的的ROC曲线下面积和剂量限制阈值分别为0.779和77.575 cc、0.769和4.22 Gy（α/β = 3）。该方程的ROC曲线下面积为0.821。
胃的和小肠的可能是预测2级或更高级别胃肠道毒性的重要参数，其剂量限制阈值可能有助于局部复发胰腺癌的再照射实践。
