[Late course conformal radiotherapy combined with chemotherapy for stage III and IV a nasopharyngeal carcinoma].

Objective: To evaluate the effect and acute toxicity of late course conformal radiotherapy combined with chemotherapy for stage III and IV a nasopharyngeal carcinoma (NPC).

Methods: Ninety-six patients with stage III and IV a NPC were randomly divided into 2 groups: test group (n = 46, undergoing late course conformal radiotherapy combined with chemotherapy) and control group (n = 50, undergoing conventional radiotherapy). Both groups were treated with one-period chemotherapy, including cisplantin, 5-fluouracil, and calcium folinate, before and after the radiotherapy. The radiotherapy of the test group consisted of 2 phases: 36.0 approximately 40.0 Gy in 18 approximately 20 fractions over 3.5-4 weeks as the first phase using conventional technique was delivered with 2 lateral opposing faciocervical fields, and then 30.0-46.0 Gy in 15-23 fractions over 3-4.5 weeks as the second phase using three-dimensional conformal radiotherapy (3D-CRT).

Results: The rates of complete remission (CR), partial remission (PR), and no change (NC) of the test group were 95.65%, 4.35%, and 0, not significantly different from those in the control group (90.00%, 10.00%, and 0, P = 0.287). The 1-year survival rate of the test group was 100%, not significantly different from that of the control group (96.00%, P = 0.170). The nasopharyngeal 1 year control rate of the test group was 97.83%, significantly higher than that of the control group (78.00%, P = 0.03). The distant metastasis rate of the test group was 8.70%, not significantly different from that of the control group (12.00%, P = 0.596). The incidence rates of radiological caries and irradiation-induced otitis media in the test group was 4.25% and 17.39% respectively, both significantly lower than those in the control group (26.00% and 42.00% respectively, P = 0.004 and P = 0.000). There was no significant difference in the incidence of nausea, vomiting, leukopenia, and severity of acute mucositis between these 2 groups.

Conclusion: Late course conformal radiotherapy combined with chemotherapy effectively improves the disease control, delays the distant metastasis, and alleviates radioactivity damnification.