Preliminary Results of Intensity-Modulated Radiotherapy in the Treatment of Nasopharyngeal Carcinoma

Purpose: To report our initial experience with intensity-modulated radiotherapy (IMRT) in the treatment of nasopharyngeal carcinoma (NPC). Materials and Methods: Between May 2005 and July 2008, 58 patients underwent definitive IMRT for NPC in the Buddhist Tzu Chi General Hospital, Taipei Branch. There were 17 females and 41 males, with a median age of 51.5 (range 27-88). The disease was Stage Ⅰ in 3 (5%), Stage Ⅱ in 12 (21%), Stage Ⅲ in 29 (50%), and Stage Ⅳ in 14 (24%). IMRT was delivered using a dynamic multileaf collimator. Thirty-one patients received concomitant cisplatin and 5FU, and seventeen patients received concomitant cisplatin. Among them, thirty-one patients received adjuvant cisplatin and 5-FU chemotherapy. The prescribed dose was 66-72 Gy to the gross tumor volume and positive neck nodes, 46.8-50 Gy to the clinically negative neck. Acute and late normal tissue effects were graded according to the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. The local control, local-regional control, distant metastasis-free, and the overall survival rates were calculated using the Kaplan-Meier method. Results : With a median follow-up of 19.3 months (range 7 to 41 months), there were 11 local recurrences at the primary site. Seven patients failed in the neck. Seven patients developed distant metastases; 6 of these patients died. The 2-year local control, local-regional control, and distant metastases-free rates were 78%, 74%, and 85% respectively. The 2-year overall survival was 86%. With 11 and 13 patents experiencing local and locoregional failure, only stage of disease was a significant predictor by multivariate analysis. IMRT with concomitant cisplatin and 5FU had treatment outcomes similar to IMRT with concomitant cisplatin alone, but this regimen was associated with more severe acute toxicity. At 19.3 months (median) after IMRT, 7% of the patients had Grade 3 xerostomia, 41% had Grade 2, 26% had Grade 1 and 2% had no xerostomia. Conclusion: Our preliminary results using IMRT for treatment of NPC were reported. Further study to compare concomitant cisplatin and 5FU with cisplatin alone is warranted. A larger case number and longer follow-up time were needed to confirm our preliminary results.