MRI technique helps track ovarian cancer therapy

The use of gadolinium-enhanced magnetic resonance imaging (MRI) and serum CA-125 assessment is effective in monitoring ovarian cancer therapy outcome, researchers report in the June issue of Radiology.

"Our oncologists use the information from the MR examination in conjunction with serum CA 125 values to monitor response to treatment or to detect recurrence," lead investigator Dr. Russell N. Low told Reuters Health. "Surgical reassessment is now seldomly performed for routine follow-up of ovarian cancer patients."Dr. Low and colleagues at Sharp Memorial Hospital, San Diego, studied 76 patients treated for ovarian cancer. Sixty-eight women had residual tumor at laparotomy and biopsy or at clinical follow-up.The MRI technique detected residual tumor in 61 patients. This amounted to a sensitivity of 90%, a specificity of 88% and an accuracy of 89%.Laparotomy showed residual tumor in 60 patients, with a sensitivity of 88% and a specificity of 100%. CA-125 values indicated residual tumor in 44 patients, giving a sensitivity of 65% and a specificity of 88%.The positive predictive value for MRI was 98%, for laparotomy it was 100% and for serum CA-125, it was 98%. Corresponding negative predictive values were 50%, 50% and 23%.The combination of MRI and CA-125 accurately identified residual tumor in 65 of the 68 patients and gave 2 false positives.Given these findings, the researchers now routinely use the MRI and CA-125 approach in lieu of laparotomy reassessment to gauge tumor response to chemotherapy. The technique "has become an integral part of the management of women with ovarian cancer at our institution," Dr. Low said. "Our techniques for gadolinium-enhanced MRI of ovarian cancer can be used on any high field MR scanner."(Source: Radiology 2005;235:918-926: Reuters Health: Oncolink: June 2005.)