Retrospecive Analysis Of Short-Term Efficacy By Helical Tomotherapy In The Treatment Of Locally Advanced Nasopharyngeal Carcinoma

Objective: Evaluate the efficacy of Helical tomotherapy(HT)by preliminary analysis of survival curves and toxicity after completion of locally advanced nasopharyngeal carcinoma treatment.Methods: Retrospectively analyzed 85 primary NPC patients who were histologically confirmed,untreated,stage III-IVA(according to the 8th edition of the American Joint Committee on Cancer /Union for International Cancer Control staging system)since December 2015 in Hunan Cancer Hospital,The affiliated Cancer Hospital of Xiangya School of Medicine(Central South University,Changsha,China).97.6%(83/85)patients received chemotherapy,including concurrent chemotherapy with or without induction chemotherapy.Those who refused chemotherapy were for personal reasons.Among these patients,97.6%(83/85)patients received induction chemotherapy(IC),94.1%(80/85)patients received concurrent chemoradiotherapy(CCRT),just 11.8%(10/85)patients received adjuvant chemotherapy(AC).All patients were performed using nasopharynx and skull base computed tomography(CT)or magnetic resonance imaging(MRI)to help depict tumor target volume(GTV).Result: At a median follow-up of 27 months,eight patients had recurred locally,one patient had neck node recurrence,three patients had distant metastases.Kaplan-Meier(K-M)analysis resulted in a 2-year estimate of progression-free survival(PFS),local relapse-free survival(LRFS),nodal relapse-free survival(NRFS),distant metastases-free survival(DMFS),and overall survival(OS)rate,were 90%,96.3%,98.8%,96.3%,and 96.3%,respectively.The acute toxicityduring chemoradiotherapy was mainly hematological toxicity,and 4 patients with concurrent chemoradiotherapy was grade 4 leukopenia.The late toxicity was mainly caused by xerostomia hearing loss.Five patients have grade 3 xerostomia,four patients have grade 3 hearing loss,and no grade 4 toxicity injury occurred.Conclusion: Helical tomotherapy achieves promising disease control and overall survival in the treatment of locally advanced NPC patients.Even with IC+CCRT+AC multi-cycle chemotherapy,induction of acute and late toxic reactions rate is still low,and timely symptomatic treatment will not affect the patient's follow-up treatment.The long-term advantages of HT in the treatment of locally advanced nasopharyngeal carcinoma patients still require further paired analysis and long-term follow-up observation.