Correlation between the CT manifestations and post-operative survival time in patients with thymic epithelial tumor / 中华放射学杂志

ABSTRACT

Objective To describe the CT manifestations of thymic epithelial tumor and explore the correlation between CT findings and post-operative tumor-related survival time. Methods Ninety-one patients who underwent CT scan before operation were reviewed retrospectively. All cases had operation and were classified according to the WHO classification. The size, contour, shape, density and enhancement of the tumors on CT were assessed. Presence of mediastinal lymphadenopathy, great vessel invasion, metastasis to the lung or plural, myasthenia gravis (MG) were also analyzed. The survival rate was obtained using the Kaplan-Meier method. The Cox model was applied to determine the factors affecting the tumor-related survivals. Chi square test was used to analyze the relationship between CT findings and WHO classification. Results Two patients were excluded because of dying of myocardial infarction and colon cancer. The total 5-year survival rate was 84.3%(n=75). Eighty-nine patients had total 91 tumors. Tumors with diameter larger than 5 cm, lobular contour, heterogenous density, and presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis were adverse factors which could significantly affect the survival time. Five-year survival rates of these factors were 72.7%, 77.3%, 76.7%, 73.8%, 30.0%, and 68.8%, respectively. Presence of MG was a favorable factor which also significantly affected the survival time (P＜0.05). While the shape and enhancement of the tumors and the age, gender of the patients did not significantly affect the survival time (P＞0.05). The result of the Cox multivariate analysis was consistent with that of the Log-rank test. For different WHO classification, there were significant different among the size or contour of the tumors, presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis (x2 value were 6.598, 5.737, 18.307, 8.465, and 15.608, respectively P＜0.05). Conclusions CT findings may be served as predictors of clinical prognosis of the thymic epithelial tumors. Adverse factors for survival time are the size of the tumors and presence of mediastinal lymphadenopathy, while MG is a favorable factor for survival time.