Preliminary Results of a Phase I/II Study of Simultaneous Boost Irradiation Radiotherapy for Locally Advanced Nasopharyngeal Carcinoma

Background: The purpose of this article is to present preliminary results of simultaneous boost irradiationradiotherapy for locally advanced nasopharyngeal carcinoma (NPC).
Methods: Fifty-eight patients who underwentsimultaneous boost irradiation radiotherapy for NPC in Cancer Center of Sun Yat-sen University betweenSeptember 2004 and December 2009 were eligible. Acute and late toxicities were scored weekly according to theRadiation Therapy Oncology Group (RTOG) acute and late radiation morbidity scoring schemes. An especialfocus was on evidence of post-radiation brain injury. Also quality of life was analysed according to the EORTC(European Organisation for Research and Treatment of Cancer) recommendations. Discrete variables werecompared by χ2 test. The Kaplan-Meier method was used to calculate the survival rates and generate survivalcurves.
Results: A total of 58 patients with a mean follow-up time of 36 months completed clinical trials.Fiftysevenpatients (98.3) achieved complete remission in the primary sites and cervical lymph nodes, with only onepatient (1.7%) showing partial remission.The most frequently observed acute toxicities during the concurrentchemoradiotherapy were mucositis and leucopenia. Four patients (6.9%) had RTOG grade 3 mucositis, whereasfour patients (6.9%) had grade 3 leucopenia. No patient had grade 4 acute toxicity. Three (5.17%) of the patientsexhibited injury to the brain on routine MRI examination, with a median observation of 32 months (range,25-42months). All of them were RTOG grade 0. The 3-year overall, regional-free and distant metastasis-freesurvival rates were 85%, 94% and 91%, respectively.
Conclusion: Simultaneous boost irradiation radiotherapyis feasible in patients with locally advanced nasopharyngeal carcinoma. The results showed excellent local controland overall survival, with no significant increase the incidence of radiation brain injury or the extent of damage.A larger population of patients and a longer follow-up period are needed to evaluate ultimate tumor control andlate toxicity.