ROLE OF INTEGRATED PET/CT IN DETECTING RECURRENT OVARIAN CANCER IN PATIENTS WITH RISING CA-125 LEVELS

Purpose: To assess the sensitivity and diagnostic accuracy of integrated PET/CT in detecting recurrent ovarian cancer in treated patients presenting with rising CA-125 levels during clinical follow-up, and compare it with those of CT alone. Materials and Methods: Retrospective study. We evaluated 45 patients with pathologically proven ovarian carcinoma who underwent PET/CT during October 2010 and Nov 2013 at our institution for suspected relapse; IRB deemed that approval for this retrospective study was not required. Out of these, 35 patients who presented with rising CA-125 levels during clinical follow-up were included in this study. Remaining 10 patients were excluded as they had normal CA-125 levels. At least three previous consecutive CA-125 readings and initial conventional imaging prior to FDG-PET/CT was noted. Sensitivity and diagnostic accuracy for tumour detection with PET/CT and CT alone was calculated; histological analysis after biopsy / second-look surgery or clinical-radiologic follow-up/response to chemotherapy was taken as reference standard. K statistics (Cohen K) was used for statistical analysis. Results: Out of 35 patients with suspected relapse 1 patient was lost to follow up. 30 patients were documented to have relapsed while in 4 patients recurrence not identified either on CT or PET-CT and they were proved to be disease free on two year follow up. Amongst these relapsed patients, 10/30 cases were proven histologically; 3 wit