Long-term outcomes of intensity-modulated radiotherapy for 868 patients with nasopharyngeal carcinoma: an analysis of survival and treatment toxicities.
OBJECTIVE
To evaluate the long-term survival outcomes and toxicity of NPC patients treated with intensity-modulated radiotherapy (IMRT).


METHODS
From May 2001 to October 2008, 868 non-metastatic NPC patients treated by IMRT were analyzed retrospectively. The Radiation Therapy Oncology Group (RTOG) criteria were used to assess toxicity.


RESULTS
With a median follow-up of 50 months (range, 5-115 months), the 5-year estimated disease specific survival (DSS), local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS) and distant metastasis-free survival (DMFS) were 84.7%, 91.8%, 96.4% and 84.6%, respectively. Of the 868 patients, 186 (21.3%) developed failure after treatment. Distant metastasis was the major failure pattern after treatment. The 5-year OS rate in patients with stage I, II, III, and IVa-b were 100.0%, 94.3%, 83.6%, and 70.5%, respectively. The 5-year LRFS rate in patients with stage T1, T2, T3, and T4 disease were 100.0%, 96.0%, 90.4%, and 83.3%, respectively (χ(2) = 26.32, P<0.001). The 5-year DMFS for N0, N1, N2, and N3 patients were 96.1%, 85.6%, 73.7%, and 62.1%, respectively (χ(2) = 65.54, P<0.001). Concurrent chemotherapy failed to improve survival rates for patients with advanced locoregional disease. The most common acute toxicities were mainly in grade 1 or 2. Compared with IMRT alone, IMRT plus concurrent chemotherapy increased the severity of acute toxicities. The incidence of brain radiation damage was relatively high (5.5%, 48/868 cases), and was not observed in patients with stage T1-2.


CONCLUSIONS
IMRT for NPC yielded excellent survival outcomes, and distant metastasis was the most commonly seen failure pattern after treatment. The role of concurrent chemotherapy for advanced locoregional stage NPC patients needs to be further investigated. Treatment-related toxicities were well tolerable. However, the incidence of brain radiation damage was relatively high, especially for patients with advanced T-stage.
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China.
Xueming
X
Sun
Department of Oncology, Affiliated Hosptial of GuiYang Medical College, GuiZhou Cancer Hospital, Guiyang, PR China.
Shengfa
S
Su
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China.
Chunyan
C
Chen
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China.
Fei
F
Han
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China.
Chong
C
Zhao
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China.
Weiwei
W
Xiao
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China.
Xiaowu
X
Deng
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China.
Shaomin
S
Huang
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China.
Chengguang
C
Lin
State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center of Sun Yat-Sen University, Guangzhou, PR China. Electronic address: lutx@sysucc.org.cn.
Taixiang
T
Lu
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D009367:Neoplasm Staging; D011379:Prognosis; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012189:Retrospective Studies; D016896:Treatment Outcome
Intensity-modulated; Nasopharyngeal neoplasms/radiotherapy; Prognosis; Radiotherapy