[Usefulness of tumor size on MR imaging in assessing the prognosis of uterine cervical cancer treated with radiation].

The purpose of this study was to assess the usefulness of MR imaging (MRI) in evaluating the primary tumor and predicting the prognosis after radiotherapy for uterine cervical carcinoma. MRI was performed before radiotherapy in 25 patients with squamous cell carcinoma. According to the staging of FIGO, 3 patients were classified as stage Ib, 1 as IIa, 5 as IIb, 13 as IIIb, 2 as IVa, and 1 as IVb. Three-dimensional diameters (transverse, anteroposterior, and craniocaudal) of the primary tumor were evaluated on T2-weighted images. For patients with tumors < or = 4 cm in craniocaudal diameter, i.e., the length of the tumor parallel to the long axis of uterine body, five-year disease-free survival (DFS) was 70%. For patients with tumors > 4 cm in craniocaudal diameter, the 5-year DFS was 37%. The difference between the two groups was statistically significant. For patients with tumors < or = 4 cm and > 4 cm in transverse or anteroposterior diameter, 5-year DFS was 63% and 50% respectively. There was no statistically significant difference between the two groups. The results showed the craniocaudal diameter of the tumor to be the most critical factor in predicting prognosis after radiation therapy in uterine cervical cancer. Moreover, MRI was an important means of evaluating the depth of uterine cervical carcinoma. In conclusion, MRI is useful in evaluating the effect of radiotherapy and predicting prognosis in uterine cervical cancer.