MR-IMAGING DURING INTRACAVITARY BRACHYTHERAPY OF VAGINAL AND CERVICAL-CANCER - PRELIMINARY-RESULTS

Intracavitary brachytherapy is an effective treatment for gynecologic cancers. Twelve magnetic resonance (MR) imaging studies were performed during intracavitary brachytherapy (10 initial studies and two during repeat brachytherapy) in 10 patients with clear cell adenocarcinoma ( n = 9) or epithelioma (n = 1). Fifty percent of the vaginal lesions di d not demonstrate high signal intensity on T2-weighted images, Individ ually tailored molded applicators allowed easy detection of abnormal v aginal parietal thickening on T1-weighted images: Results in seven cas es were concordant with results of clinical examination, and there wer e no false-negative results. MR imaging was useful in controlling the relationships between the tumor and the applicator and facilitated tre atment planning, since the radiation dose to the tumor volume and adja cent critical organs could be calculated accurately. Limitations of MR imaging were underestimation of superficial vaginal tumors and the in ability to differentiate between tumor and inflammation after recent s urgery or repeat intracavitary brachytherapy. MR imaging during intrac avitary brachytherapy appears to be a useful adjunct to clinical exami nation.