Initial experience of using intensity modulated radiation therapy (IMRT) for recurrent nasopharyngeal carcinoma

Abstract

chemotherapy. Radiosurgery was delivered to the primary tumor site 4 weeks after the completion of EBRT in one fraction of 7-15 Gy (median 12 Gy).Results: With a median follow up of 31.4 months (range: 3.9-84.6), there were 14 distant relapses, but no local failures. The 3-year local control rate was 100%, freedom from distant metastasis (FFDM) was 69% and overall survival was 75%. Univariate analysis revealed that N-stage (favoring N0-1, p ϭ 0.04) and WHO histology (favoring WHO III, p ϭ 0.0001) were significant prognostic factors for FFDM. WHO histology was the only significant factor for FFDM on multivariate analysis (pϭ 0.002, hazard ratio (HR) ϭ 13). Age (p ϭ 0.04), gender (favoring female, p ϭ 0.04) and WHO histology were significant prognostic factors for survival on univariate analysis. WHO histology (pϭ0.004, HR ϭ 10.5) and age (pϭ0.01, HR 1.07/year) were significant factors for survival on multivariate analysis. Late toxicity included transient cranial nerve weakness in 4, radiation-related retinopathy in 1 and asymptomatic temporal lobe necrosis in 3 patients who originally had intracranial tumor extension.Conclusions: Stereotactic radiosurgical boost following fractionated EBRT provides excellent local control in NPC patients. Late toxicity appears to be acceptable to date. With improved local control, more effective systemic treatment is needed in these patients.