Irradiation of the cervix uteri: value of unenhanced and contrast-enhanced MR imaging.

Abstract

To analyze the value of magnetic resonance (MR) imaging after radiation therapy for cancer of the cervix. Eighty-nine MR images were retrospectively studied in 69 patients aged 46.3 years +/- 11.5. MR findings of tumor recurrence and irradiation changes were correlated with time after radiation therapy; paracentral radiation dose (dose to point A); and in patients with pretreatment images, primary tumor size and stage. Overall accuracy of MR in diagnosis of tumor recurrence was 78% (positive predictive value, 65%; negative predictive value, 97%). In MR examinations less than 6 months after the beginning of radiation therapy, accuracy (69%) and specificity (46%) were significantly lower than in examinations more than 6 months later (88%, P = .0032; 81%, P = .0166, respectively). Comparison of pre- and posttreatment MR findings and knowledge of stage or initial tumor size did not affect MR results. Overall, diagnosis was best with unenhanced T2-weighted images, but in patients with adnexal or pelvic sidewall recurrence and in patients with treatment complications (eg, fistula formation), contrast enhancement did help.