Long term survival analysis of middle and lower thoracic esophageal carcinoma of stage T4 N (+) treated with 3DRT / 中华放射肿瘤学杂志

ABSTRACT

Objective To observe the long?term survival and adverse reactions in patients with stage T4 N (+) Ⅲ middle and lower thoracic esophageal carcinoma undergoing intensity?modulated radiotherapy ( IMRT) . Methods From 2004 to 2010, 300 patients with stage T4 N (+) Ⅲ middle and lower thoracic esophageal carcinoma, consisting of 202 treated with three?dimensional conformal radiotherapy ( 3DCRT ) and 98 treated with IMRT, were enrolled as subjects. All patients received conventionally fractionated radiotherapy with a prescribed dose of 60 Gy. The long?term survival and adverse reactions were compared between patients treated with the two different radiotherapy regimens. The survival rates were calculated by the Kaplan?Meier method and analyzed by the log?rank test. Results The 5?and 7?year sample sizes were 239 and 120, respectively. The 3DCRT group had significantly lower 1?, 3?, 5?, and 7?year local control (LC) and overall survival (OS) rates than the IMRT group (64. 4% vs. 68. 3%, 40. 6% vs. 55. 3%, 38. 3% vs. 51. 9%, 34. 2% vs. 51. 9%, P=0. 048;54. 5% vs. 63. 3%, 19. 8% vs. 34. 7%, 14. 7% vs. 24. 4%, 10. 9% vs. 20. 3%, P=0. 013) . The stratified analysis showed that for patients older than 65 years, with the length of esophageal lesion>8. 0 cm before radiotherapy, the largest diameter of esophageal lesion in computed tomography image>4. 6 cm, gross tumor volume ( GTV)>60 cm3 , metastases to adjacent tissues or organs, stage N2 , and without chemotherapy, the IMRT group had a significantly higher OS rate than the 3DCRT group (P=0. 022,0. 003,0. 022,0. 034,0. 016,0. 044,0. 047). The GTV Dmin and GTVD100 were significantly higher in the IMRT group than in the 3DCRT group ( P=0. 000,0. 000) , while the Dmax of the spinal cord was significantly lower in the IMRT group than in the 3DCRT group ( P=0. 000) . Compared with the 3DCRT group, the IMRT group had a significantly higher incidence of acute radiation?induced esophagitis, particularly grade 1?2 esophagitis (P=0. 000). The mortality rate caused by local tumor was significantly higher in the 3DCRT group than in the IMRT group ( P= 0. 039 ) . Conclusions In the treatment of locally advanced middle and lower thoracic esophageal carcinoma, IMRT is safe and effective;it significantly improves the LC rate and long?term survival without severe toxicity to normal tissues. The results of this retrospective study need to be confirmed by prospective randomized controlled studies.