Impact of spiral tomotherapy combined with intensity-modulated radiotherapy for nasopharyngeal carcinoma

Background: Nasopharyngeal carcinoma (NPC) is a radiosensitive tumor located in a complex anatomical region, necessitating highly conformal radiotherapy.Spiral tomotherapy (TOMO), an advanced form of intensity-modulated radiotherapy (IMRT), integrates dose-guided and image-guided delivery to improve tumor targeting.This study aimed to compare the clinical efficacy, toxicity, and dosimetric advantages of spiral TOMO versus conventional IMRT in NPC patients.Materials and Methods: A total of 80 NPC patients treated between September 2017 and February 2019 were retrospectively reviewed.Patients were assigned to either spiral TOMO (n = 40) or IMRT (n = 40) groups.Radiotherapy doses ranged from 50.7 to 71.1 Gy, delivered over 6-6.5 weeks.Clinical response was assessed using RECIST criteria, while treatment toxicity was graded according to the standards of the American Society for Radiation Oncology.Dosimetric evaluation included target coverage and organ-at-risk (OAR) sparing parameters.Results: Spiral TOMO achieved a total short-term efficacy rate of 97.5%, compared to 95.0% for IMRT.Although myelosuppression rates were comparable (P>0.05), the TOMO group showed significantly lower rates of acute skin reactions (12.5% vs. 60%) and acute dry mouth (10% vs. 45%) (P