ABSTRACT
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.
ABSTRACT
Objective To investigate the prognosis of patients with nasal NK/T cell lymphoma receiving different treatment modalities. Methods From 1990 to 2004, 85 patients with stage ⅠE and ⅡE primary nasal NK/T cell lymphomas were retrospectively studied. Twenty patients received chemotherapy of CHOP regimen alone, 11 patients received radiotherapy only, 6 patients received radiotherapy followed by more than 2 cycles of chemotherapy, and 48 patients received more than 2 cycles of chemotherapy followed by radiotherapy. Survival analysis was performed by the Kaplan-Meier method, the difference between groups was evaluated by the Log-rank test, and the Cox regression model was used for multivariate analysis. Results The 5-year overall survival rate (OS) was 40%. The 5-year OS was 57% and 28% for limited stage ⅠE and extended stage ⅠE(X2 =8. 87, P =0. 003), and 23% for stage ⅡE, which was similar to extended stage ⅠE (X2 =0. 19, P-0. 664). The 5-year OS was 13%, 54% and 47% for chemotherapy alone, radiotherapy followed with or without chemotherapy, and chemotherapy followed by radiotherapy, respectively. The last two groups had better OS than chemotherapy alone (P = 0. 030 and 0.049). The 5-year OS was 58% and 12% for patients achieving complete response (CR) and uncomplete response (X2 = 30.68, P = 0. 000).The CR rate was 56% and 86% for radiotherapy of ≤50 Gy and >50 Gy (X2 =6.11, P=0. 013). The corresponding 5-year relapse-free survival rate was 89% and 84% (X2 =0.36, P=0.551). Of 68 patients receiving initial chemotherapy, the CR rate of those who received ≤2, 3-4 and ≥5 cycles was 0, 20%and 3 3 % , respectively (X2 = 7.65 , P = 0. 022) . For 5 0 patients who received ≥ 3 cycles of initial chemotherapy and 17 patients who received initial radiotherapy of ≥40 Gy, the CR rate was 28% and 88%(χ2= 18. 75, P= 0. 000). In patients with pathological nodular and ulcer type, the CR rates with radiotherapy were higher than with chemotherapy (100%: 38%, χ2 = 7.92, P = 0. 005; and 100%: 11%,χ2 = 14.40, P = 0. 000). Multivariate analysis showed that stage and recent effect were the independent prognostic factors. Conclusions The initial radiotherapy with 50 Gy is appropriate for early stage nasal NK/T cell lymphomas. Combined chemotherapy could be used for extended stage ⅠE and ⅡE, but the outcome of CHOP regimen is poor.