1. Department of Radiation Oncology, Cancer Center, First People's Hospital of Foshan Affiliated to Sun Yat-sen University, Foshan 528000, China;
2. Sun Yat-sen University Cancer Center; State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China;
3. Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
* These authors contributed equally to this work.
Background: This study evaluated the survival outcomes and toxicities of intensity-modulated radiation therapy (IMRT) based on the RTOG 0225/0615 RT protocols in patients with nasopharyngeal carcinoma (NPC) from a region of China where this tumor type is endemic.
Methods: A total of 455 patients with non-metastatic, histologically-confirmed NPC were retrospectively reviewed. All patients were treated by IMRT using the RTOG 0225/0615 RT protocols; 91.1% (288/316) of patients with stage III-IVb NPC received concurrent chemotherapy +/- induction chemotherapy or adjuvant chemotherapy.
Results: Estimated four-year overall survival (OS), failure free survival (FFS), local relapse free survival (LRFS), regional relapse free survival (RRFS) and distant metastasis free survival (DMFS) were 83.8%, 80.5%, 94.3%, 96.7% and 85.8%, respectively. T and N category were significant prognostic factors for OS, FFS, RRFS and DMFS; and T category, for LRFS. In-field failure was the major loco-regional failure pattern. During RT, 206 (45.3%) patients experienced acute grade 3-4 toxicities. The most common acute toxicity was mucositis; 124 (27.2%) patients experienced grade 3-4 mucositis; 46 (10.1%) experienced serious late toxicities. The most common late toxicity was MRI-detected radiation-induced temporal lobe necrosis (6.8%).
Conclusions: The RTOG IMRT protocols are feasible for patients with NPC from the endemic regions of China.
Keywords: Nasopharyngeal carcinoma, intensity-modulated radiotherapy, RTOG 0225, RTOG 0615.