Clinical curative analysis on intensify modulated radiotherapy to 51 cases of nasopharyngeal carcinoma

Objective To observe the acute toxicity and preliminary clinical efficacy of intensify modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).And compare it with threedimensional conformal radiotherapy ( 3D-CRT ). Methods From May 2008 to May 2009, 51patients with nasopharyngeal carcinoma were treated by IMRT with 2.2Gy/fraction at gross tumor volume (GTV) to a total dose of 70.4-74.8Gy/32-34 fraction, 1.8Gy/fraction at the clinical treatment volume Ⅰ (CTV 1) to a total dose of 61.2-64.8Gy/34-36 fraction and 2.0Gy/fraction at the clinical treatment volume Ⅱ (CTV2) to a total dose of 50-54Gy/25-27 fraction: 59 patients with nasopharyngeal carcinoma were treated by 3D-CRT with 2.0Gy/fraction at gross tumor volume-nx (GTVnx) to a total dose of 70-78 Gy/35-39 fraction,2.0Gy/fraction at gross tumor volume-nd (GTVnd) to a total dose of 70Gy/35 fraction, 2.0Gy/fraction at the clinical treatment volume Ⅰ (CTV 1) to a total dose of 60-64Gy/30-32 fraction and 2.0Gy/fraction at the clinical treatment volume Ⅱ (CTV2) to a total dose of 50-54Gy/25-27 fraction. Using chemotherapy of DDP+5-Fu in depend on the stage, Results Dose volume histogram ( DVH ) showed a better dose distribution and protection for normal tissue in group of IMRT, especially parotid.Acute toxicity was well tolerated and no grade V side effects occurred in group of IMRT. The patients showed xerostomia by IMRT are less than the group by 3D-CRT. The difference between the two groups was obvious. 28 patients had complete response(90.3%) while 3 patients had partial response after completion of treatment, giving a 1-year survival rate of 100%. Conclusion IMRT yields better dose distribution and acceptable toxicity than the 3D-CRT in both early and advanced stage nasopharyngeal carcinoma. The preliminary clinical result is encouraging, but clinical efficacy and complications for long-term need to be further studied. Key words: Nasopharyngeal carcinoma(NPC); Intensify modulated radiotherapy (IMRT);  Threedimensional conformal radiotherapy ( 3D-CRT )