Preliminary Results of Re-irradiation for Locally Recurrent Nasopharyngeal Carcinoma with Intensity Modulated Radiotherapy

Abstract

To evaluate the treatment outcome in patients with locally recurrent nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). From March 2005 to March 2007, 39 patients with locally recurrent NPC received re-irradiation using IMRT. The rT classification distribution was 7 for rT1, 10 for rT2, 13 for rT3, and 9 for r T4. Median time from first course of radiotherapy to re-irradiation was 38 months. The median prescribed dose was 66.7 Gy (range, 54-72.1 Gy) with 2-2.3 Gy per fractionation. Two patients received 16 Gy brachytherapy boost in 2 fractions. Twenty-nine patients received cisplatin-based induction or adjuvant chemotherapy. Median follow-up time was 14 months (range, 4-29 months). After re-irradiation, 64.5% of patients had complete regression of primary tumor. One-year loco-regional progression-free, distant metastasis-free and overall survival rates were 96.6, 88.5, and 69.3%, respectively. One patient developed recurrence in the nasopharynx. Four patients developed metastases at a distant site: one in the bone and liver, one in the lung, one in the liver and one in the bone. Acute toxicity (skin, mucosa, and xerostomia) was acceptable according to the Radiation Therapy Oncology Group criteria. The necrosis was seen after the end of IMRT in 8 patients with bleeding. The fractional dose is 2.3Gy in five patients of them. Our preliminary results showed that good control can be achieved using IMRT . As high dose/ fractional dose IMRT can result in radio-necrosis of nasopharyngeal mucosa, the prescription dose/fractional dose should be suitably decreased. More patients and longer term follow-up are warranted to evaluate late toxicity and treatment outcome