Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
Cancer Med. 2020 Dec;9(23):8832-8843. doi: 10.1002/cam4.3494. Epub 2020 Oct 6.
A small proportion of nasopharyngeal carcinoma (NPC) patients show resistance to induction chemotherapy (IC). This study sought to investigate the impact of tumor volume enlargement after IC on the dosimetric parameters of subsequent radiotherapy. The records of a total of 240 locally advanced NPC patients who received IC followed by concurrent chemoradiotherapy were retrospectively reviewed. Patients with a tumor volume enlargement of ≥10% and patients with a tumor volume reduction of ≥10% after induction chemotherapy were classified as the enlargement group and the control group, respectively. The dosimetric parameters of the planning target volumes (PTVs) and the organs at risk (OARs) were compared between the matched groups after propensity score matching (PSM). For the gross tumor volume of nasopharynx (GTVnx), 21 patients and 127 patients were classified as the enlargement group and the control group, respectively. After matching, 20 sub-pairs of 40 patients were generated in the post-PSM cohort. The GTVnx enlargement group exhibited no significant disadvantages in all of the dosimetric parameters, except in the planning organ-at-risk volume (PRV) of contralateral lens (Dmax, 722 cGy vs. 634 cGy, p = 0.041). For the gross tumor volume of lymph nodes (GTVnd), 44 patients and 144 patients were classified as the enlargement group and the control group, respectively. After matching, 39 sub-pairs of 78 patients were generated in the post-PSM cohort. The GTVnd enlargement group exhibited no significant disadvantages in all of the dosimetric parameters. Univariate and multivariate analyses showed that the enlargement of GTVnx and the enlargement of GTVnd were not independently associated with any of the dosimetric parameters. A tumor volume enlargement of ≥10% in GTVnx or GTVnd after induction chemotherapy has no significant impact on the dosimetric parameters of subsequent radiotherapy in locally advanced NPC.
一小部分鼻咽癌（NPC）患者对诱导化疗（IC）表现出耐药性。本研究旨在探讨 IC 后肿瘤体积增大对后续放疗剂量学参数的影响。回顾性分析了 240 例接受 IC 后同步放化疗的局部晚期 NPC 患者的记录。肿瘤体积增大≥10%的患者和诱导化疗后肿瘤体积缩小≥10%的患者分别归入增大组和对照组。通过倾向评分匹配（PSM）后，比较匹配组之间的计划靶区（PTV）和危及器官（OAR）的剂量学参数。对于鼻咽原发肿瘤体积（GTVnx），21 例和 127 例患者分别归入增大组和对照组。匹配后，在 PSM 后队列中生成了 20 对 40 例亚组。除对侧晶状体计划器官受量（PRV）的 Dmax（722 cGy 与 634 cGy，p=0.041）外，GTVnx 增大组在所有剂量学参数中均无明显劣势。对于颈部淋巴结原发肿瘤体积（GTVnd），44 例和 144 例患者分别归入增大组和对照组。匹配后，在 PSM 后队列中生成了 39 对 78 例亚组。GTVnd 增大组在所有剂量学参数中均无明显劣势。单因素和多因素分析表明，GTVnx 和 GTVnd 的增大与任何剂量学参数均无独立相关性。诱导化疗后 GTVnx 或 GTVnd 的肿瘤体积增大≥10%，对局部晚期 NPC 后续放疗的剂量学参数无显著影响。
