An Audit on the Role of PET/CT in Recurrent Ovarian Cancer in a Tertiary Care Centre

Abstract

Ovarian cancers tend to recur in 50–70 % cases. Metastases from ovarian cancer primarily involve the peritoneum rather than parenchymal sites; thus, the presence of small-volume recurrence or metastatic deposits on the visceral surfaces poses a challenge for interpretation of CT and MR images. PET/CT utilizes its property of higher accumulation in malignant cells to provide both anatomic and functional information for diagnosing malignant tumors. The objectives of the study were to find the correlation between PET/CT findings and final histopathological diagnosis in suspected ovarian cancer recurrences. PET/CT was done in cases with rising or above normal CA-125. These patients with abnormal PET/CT findings were taken up for a secondary cytoreductive surgery, and histopathological reports were taken as the standard against which PET/CT positive findings were compared. Of the 52 patients with suspected recurrence, 40 patients with a PET-CT scan with findings suggestive of an avid uptake underwent surgery. Of the 40 patients who underwent a secondary cytoreductive surgery, 38 had histopathologically confirmed recurrence. PET-CT detected a total of 86 lesions, of which 38 were in the lymph nodes, 32 were peritoneal lesions and 14 were pelvic, 2 were metastatic in the parenchyma of liver. Mean diameter of the lesions detected was 2.2 cm (range 0.3–6.2 cm). PET-CT accurately identified 72 of the 80 histopathologically proven lesions. The overall lesion-based sensitivity of PET-CT is 90 %, specificity 66.7 %, positive predictive value being 83.7 % and negative predictive value 77.7 % and the overall accuracy being 81.9 %. Correlation between PET/CT and histopathological disease: κ (Cohen value) = 0.88 suggests excellent correlation. Selected patients with ovarian cancer recurrence may benefit from PET-CT at the time of even no. or minimal CA-125 elevation by early detection and successful cytoreduction.