早期鼻腔和韦氏环NK/T细胞淋巴瘤调强放疗的初步结果

目的 回顾性分析早期鼻腔和韦氏环NK/T细胞淋巴瘤调强放疗(IMRT)的初步临床结果.方法 48例患者中42例为原发鼻腔NK/T细胞淋巴瘤,6例为韦氏环NK/T细胞淋巴瘤.根据Ann Arbor分期,I_E期37例,Ⅱ_E期11例.22例接受单纯放疗,26例接受放化疗.95%计划靶体积(PTV)处方剂量为50 Gy.放疗副反应分级采用RTOG标准.局部控制率和生存率用Kaplan-Meier法计算.结果 中佗随访18个月,2年局部控制率、无进展生存率和总生存率分别为100%、73%和75%.剂量体积直方图显示PTV最高、平均、最低剂量均值分别为62.6、55.0、20.3 Gy,接受低于95%处方剂量的体积仅占靶体积的2.4%.脑干、脊髓、视交叉、左视神经、右视神经、左晶体和右晶体接受的最高剂量均值分别为43.5、32.7、48.2、50.3、51.3、7.8和7.6 Gy.左腮腺、右腮腺、垂体、左颞颌关节和右颞颌关节接受的平均剂量分别为17.1、16.5、32.5、47.3和46.8 Gy.全组口腔黏膜反应1级37%、2级41%、3级16%;皮肤急性反应1级78%、2级16%;急性口干反应1级65%、2级18%.结论 鼻腔和韦氏环NK/T细胞淋巴瘤IMRT使靶区剂量分布均匀,有效保护了腮腺和其他重要器官,并取得了很好的局部控制率和总生存率.

Toxicity and treatment outcome of intensity-modulated radiation therapy for early stage nasal and Waldeyer ring NK/T-cell lymphoma

Objective Radiotherapy is the primary therapy for early stage nasal-type NK/T-cell lymphoma of the nasal or Waldeyer ring. This study aimed to investigate the clinical outcome of the disease treated with intensity-modulated radiation therapy (IMRT). Methods From November 2003 to June 2008, 48 patients with nasal or Waldeyer ring NK/T-ceil lymphoma underwent IMRT. The tumors were located in the nasal in 42 patients ,and the Waldeyer ring in 6. According to the Ann Arbor staging system, the disease was stage Ⅰ_E in 37 patients (77%), stage Ⅱ_E in 11 (23%). Of these patients, 22 received radiotherapy alone, the other 26 received combined chemotherapy and radiotherapy. Prescribed radiation dose was defined as a minimun dose of 95% PTV. Acute and late toxicities were scored by Radiation Therapy Oncology Group morbidity criteria. Survival probabilities were estimated using Kaplan-Meier method. Results With a median follow-up of 18 months, the 2-year local control, overall survival and progression-free survival rates were 100%, 75% and 73%, respectively. The average maximum, mean and minimum delivered doses were 62.6 Gy, 55.0 Gy and 20.3 Gy to the PTV. Only 2.4% of the PTV received less than 95% of the prescribed dose. The average maximum dose to the brain, spinal cord, optic chiasm, left optical nerve, right optical nerve, left len and right len was 43.5 Gy, 32. 7 Gy, 48.2 Gy, 50. 3 Gy, 51.3 Gy, 7. 8 Gy and 7.6 Gy, respectively. The average mean dose to the left parotid, right parotid, pituitary, left T-M joint and right T- M joint was 17. 1 Gy , 16. 5 Gy , 32. 5 Gy , 47.3 Gy and 46. 8 Gy , respectively. Acute mucositis was observed in 37% of patients with Grade 1, 41% with Grade 2, and 16% with Grade 3. Skin toxicity was observed in 78% of patients with Grade 1 and 16% with Grade 2. Acute xerestoma was observed in 65% of patients with Grade 1 and 18% with Grade 2. Conclusions IMRT provids excellent tumor target coverage and reduces the dose to the critical normal tissues such as the salivary glands. Longer follow-up is needed to assess the long-term overall survival and local control.