MRI evaluation of treatment effect of radiotherapy for cancer of uterine cervix

Objective: To present the findings of cervical carcinoma before , during and after radiation therapy by magnetic resonance (MR) imaging and to investigate MR images in the evaluation of cervical carcinoma response to radiation therapy. Methods: Pelvic MR imaging was performed before, during, and at different intervals after radiation therapy in 23 patients with cervical carcinoma. The MR scanning included axial T1W, SE, axial and sagittal T2WI TSE, coronal SPIR and axial, sagittal and coronal GD-DTPA-enhanced T1WI SE. The changes of carcinoma lesion in size and signal were evaluated on MR images. Results: At the end of external beam radiotherapy (EBRT), the extent of tumor volume shrinkage was less than 85% in 9 patients and more than 85% in 14 patients. 'No enhanced area' in carcinoma lesion was observed in 7 patients at GD-DTPA-enhanced T1W imaging, of them 6 showed residual tumor after radiation treatment. In 16 patients who did not present 'No enhanced area', 13 patients showed tumor shrinkage at the end of EBRT greater than 85%. Moreover, only 2 patients were demonstrated as having tumor residual after radiation treatment. Complete response to radiation therapy were usually presented as hypotense signal at T2W, SPIR MR image and slight or no enhancement at GD-DTPA T1W images. Conclusion: MR imaging is helpful in evaluating cervical carcinoma response to radiation therapy with the extent of tumor volume shrinkage and enhanced T1W findings at the end of EBRT as the important prognostic factors in determining the treatment outcome. (authors)