Yan Ouying, Wang Hui, Han Yaqian, Fu Shengnan, Chen Yanzhu, Liu Feng
Department of Radiation Oncology, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.
The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.
Front Oncol. 2021 Aug 23;11:709622. doi: 10.3389/fonc.2021.709622. eCollection 2021.
An optimal approach to define tumor volume in locoregionally advanced nasopharyngeal carcinoma (NPC) using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) remains unclear. This retrospective study aimed at comparing the outcomes and toxicities of different FDG-PET/CT-guided techniques for primary tumor volume delineation in locoregionally advanced NPC.
From August 2015 to February 2018, 292 patients with stage III-IVB NPC received FDG-PET/CT-guided IMRT. Three PET/CT-based techniques were used to determine the gross tumor volume (GTV) as follows: visual criteria (group A; n = 98), a standard uptake value (SUV) threshold of 2.5 (group B; n = 95), and a threshold of 50% maximal intensity (group C, n = 99) combined with a dose-painting technique.
In groups A, B, and C, the 5-year LRFS rates were 89.4%, 90.0%, and 97.8%, respectively (p = 0.043). The 5-year DMFS rates were 75.1%, 76.0%, and 87.7%, respectively (p = 0.043). The 5-year DFS rates were 70.9%, 70.3%, and 82.2%, respectively (p = 0.048). The 5-year OS rates were 73.5%, 73.9%, and 84.9%, respectively (p = 0.038). Group C showed significantly higher 5-year LRFS, LRRFS, DMFS, DFS, and OS than those in groups A and B (p < 0.05). No statistically significant differences were observed between the three study groups in the cumulative incidences of grade 3-4 acute and late toxicities. Multivariate analyses showed that the PET/CT-guided technique for target volume delineation was an independent prognostic factor for 5-year LRFS, DFS, DMFS, and OS (p = 0.039, p = 0.030, p = 0.035 and p = 0.028, respectively), and was marginally significant in predicting LRRFS (p = 0.080).
The 50% SUVmax threshold regimen for GTV delineation with dose-painting appeared to be superior to the visual criteria or SUV2.5 threshold in locoregionally advanced NPC, and there was no increased toxicity.
使用18F-氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描（FDG-PET/CT）来定义局部晚期鼻咽癌（NPC）肿瘤体积的最佳方法仍不明确。本回顾性研究旨在比较不同FDG-PET/CT引导技术在局部晚期NPC中勾画原发肿瘤体积的疗效和毒性。
2015年8月至2018年2月，292例III-IVB期NPC患者接受了FDG-PET/CT引导的调强放疗（IMRT）。采用三种基于PET/CT的技术来确定大体肿瘤体积（GTV），具体如下：视觉标准（A组；n = 98）、标准摄取值（SUV）阈值为2.5（B组；n = 95）以及最大强度的50%阈值（C组，n = 99）并结合剂量描绘技术。
A组、B组和C组的5年局部区域无复发生存率（LRFS）分别为89.4%、90.0%和97.8%（p = 0.043）。5年远处无转移生存率（DMFS）分别为75.1%、76.0%和87.7%（p = 0.043）。5年无病生存率（DFS）分别为70.9%、70.3%和82.2%（p = 0.048）。5年总生存率（OS）分别为73.5%、73.9%和84.9%（p = 0.038）。C组的5年LRFS、局部区域复发无复发生存率（LRRFS）、DMFS、DFS和OS均显著高于A组和B组（p < 0.05）。三个研究组在3-4级急性和晚期毒性的累积发生率方面未观察到统计学显著差异。多因素分析显示，PET/CT引导的靶区勾画技术是5年LRFS、DFS、DMFS和OS的独立预后因素（分别为p = 0.039、p = 0.030、p = 0.035和p = 0.028），在预测LRRFS方面边缘显著（p = 0.080）。
采用剂量描绘的GTV勾画50%SUVmax阈值方案在局部晚期NPC中似乎优于视觉标准或SUV2.5阈值，且毒性未增加。
