Gross tumor volume determines toxicity and quality of life for patients with nasopharyngeal carcinoma treated by concurrent chemoradiotherapy with simultaneously integrated boost technique
Abstract Background: To evaluate the impact of gross tumor volume (GTV) on toxicities and quality of life (QoL) for patients with nasopharyngeal carcinoma (NPC) treated by concurrent chemoradiotherapy with simultaneously integrated boost technique (chemo-SIB-IMRT). Methods: A total of 278 NPC patients with stage II-IVb treated by chemo-SIB-IMRT were enrolled. Toxicities were evaluated according to CTCAE version 4.03. QoL outcomes (n=219) were measured by using the EORTC QLQ-C30 and HN35 questionnaires at the time point of 12 months after chemo-SIB-IMRT. Results: A higher GTV was observed to be significantly associated with a higher mean or maximal dose in most organs at risk, together with more severe acute (mucositis, dermatitis, weight loss, and use of analgesic) and late toxicities (xerostomia, neck fibrosis, and radiation neuropathy). A linear regression model revealed that a higher GTV was significantly associated with a decline in role functioning and an increment in taste/smell, speech, social eating, opening mouth, dry mouth, and sticky saliva. Conclusion: GTV is the determining factor of some acute and late toxicities and QoL scales for NPC patients treated by chemo-SIB-IMRT.