A preliminary study of three-dimensional conformal radiotherapy with different clinical target volumes for esophageal cancer

Abstract

Objective To investigate the value of prophylactic irradiation to the lymphatic drainage area in radical three-dimensional conformal radiotherapy (3DCRT) and to evaluate the efficacy and adverse effects of 3DCRT with different clinical target volumes.Methods A retrospective analysis was performed on the records of 219 esophageal cancer patients without distant metastasis who received 3DCRT from January 2005 to December 2010.One hundred and five patients received involved-field irradiation (IFI) with a total dose of 54-66 Gy;114 patients received elective nodal irradiation (ENI) with a total dose of 46-52 Gy; the prescribed dose to the primary lesion was 56-70 Gy.The Kaplan-Meier method was used to calculate local control (LC) and overall survival (OS) rates,and the log-rank test was used for univariate prognostic analysis.Results The 1-,3-,and 5-year sample sizes were 219,172 and 67,respectively.The 1-,3-,and 5-year LC rates for IFI group were 63.0％,39.1％,and 27.2％,respectively,versus 70.5％,53.3％,and 51.7％ for ENI group (x2 =6.22,P =0.013) ;the 1-,3-,and 5-year OS rates for IFI group were 67.6％,24.9％,and 15.0％,respectively,versus 73.7％,45.1％,and 26.0％ for ENI group (x2=5.04,P =0.025).The univariate stratified analysis showed that the LC and OS rates were significantly higher in the ENI group than in the IFI group for patients with middle-or lower-thoracic primary lesion or N0 disease (P=0.007,0.015;P=0.054,0.013).Conclusions For esophageal cancer patients with middle-or lower-thoracic primary lesion or without lymph node metastasis,prophylactic irradiation to the lymphatic drainage area can increase LC and OS rates. Key words: Esophageal neoplasms/three-demensional radiotherapy; Involved-field irradiation; Elective nodal irradiation; Prognosis