Effectiveness and toxicity of helical tomotherapy for patients with locally recurrent nasopharyngeal carcinoma.

PURPOSE: We assessed therapeutic outcomes of reirradiation with helical tomotherapy (HT) for locoregional recurrent nasopharyngeal carcinoma (LRNPC) patients. METHODS AND MATERIALS: Treatment outcomes were evaluated retrospectively in 17 consecutive LRNPC patients receiving HT between 2006 and 2012. Median age was 57 years and most patients (n = 13) were male. Simultaneous systemic therapy was applied in 5 patients. Initial treatment covered the gross tumor volume with a median dose of 70 Gy (60-81.6 Gy). Reirradiation was confined to the local relapse region with a median dose of 63 Gy (50-70.2 Gy), resulting in a median cumulative dose of 134 Gy (122-148.2 Gy). The median time interval between initial and subsequent treatment was 42 months (11-126).
RESULTS: The median follow-up for the entire cohort was 23 and 35 months for survivors. Three patients (18 %) developed both local and distant recurrences and only one patient (6 %) suffered from isolated local recurrence. Two-year actuarial DFS and LC rates were 74 and 82 %, respectively. Two-year OS rate was 79 %. Acute and late grade 2 toxicities were observed in 8 patients (47 %). No patient experienced late grade ≥3 toxicity. Late toxicity included fibrosis of skin, hypoacusia, dysphagia, and xerostomia. Patients with higher Karnofsky performance status scores associated with a lower risk of mortality (HR 0.85, p = 0.015).
CONCLUSION: Reirradiation with HT in patients with LRNPC is feasible and yields encouraging results in terms of local control and overall survival with acceptable toxicity.