Abstract: Objective  To  investigate the relationship between gross tumor volume (GTVT) and prognosis of esophageal cancer patients undergoing radical radiotherapy detected by chest enhanced multislice spiral CT (MSCT) scan. Methods  A retrospective analysis  was performed in 392 patients with esophageal cancer who underwent radical radiotherapy. The relationship between GTVT and its clinical T stage and clinical TNM staging were analyzed. The relationship between GTVT and patient prognosis was analyzed.Results  The GTVT of the whole group was 7.55222.33 cm3 (median 45.88  cm3),  which was closely correlated with clinical T stage and TNM stage (r=0.673,  0.596,  P=0.000).According to the analysis result of ROC curve,  the best cutoff value was obtained when the value of GTVT  was 50.00  cm3.Multivariate analysis showed that the patients'  age,  clinical TNM staging and GTVT were independent factors affecting overall survival （OS）(P=0.000, 0.002, 0.014);  and the patients' lesion,  clinical TNM staging and GTVT was the independent factor influencing the patients' diseasefree survival （DFS）(P=0.020, 0.013, 0.006). Conclusion  The size of GTVT detected by chest MSCT scan before radiotherapy can predict the prognosis of esophageal cancer patients,  and the prognosis of patients with smaller GTVT is better.

Key words: esophageal neoplasms, radical radiotherapy, gross tumor volume, prognosis