Effectiveness and Toxicities of Intensity-Modulated Radiation Therapy for Patients with T4 Nasopharyngeal Carcinoma

OBJECTIVE To evaluate the effectiveness and toxicities in T4 nasopharyngeal carcinoma (NPC) using intensity-modulated radiotherapy (IMRT) combined with chemotherapy. METHODS This is a retrospective analysis of 81 patients treated with intensity-modulated radiotherapy (IMRT). All the primary tumors were attributed to T4 stage according to the AJCC2010 staging system. And the distribution of disease by N stage was N0 in 13.6%, N1 in 30.9%, N2 in 37%, and N3 in 18.5%. Cisplatin-based chemotherapy was offered to all patients. Radiotherapy-related toxicities were graded according to the Acute and the Late Radiation Morbidity Scoring Criteria of the Radiation Therapy Oncology Group (RTOG) scoring criteria. Chemotherapy-related toxicities were graded by National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 3.0. Prognostic factors were assessed by univariate analysis. RESULTS With a median follow-up of 37 months, 12 patients experienced local regional failure and total distant metastasis occurred in 18 patients, representing the major mode of failure. Ten patients died. Among them, 70% died of distant metastasis. The 3-year actuarial rates of local failure-free survival (LFFS), regional failure-free survival (RFFS), distant failure-free survival (DFFS), overall survival (OS), and progression-free survival (PFS) were 83.8%, 97.4%, 81.3%, 90%, and 69.7%, respectively. Acute and late toxicities were mild or moderate. CONCLUSIONS IMRT provides excellent local-regional control for T4 NPC. Distant metastasis remains the major cause of treatment failure. Further explorations of the sequence and regimen of systemic therapy are needed in the future.