Objective: To prospectively identify combined PET/CT predictors of incomplete/suboptimal primary cytoreduction in advanced ovarian cancer.
Methods: From September 2004 to March 2007, 179 patients with a Risk of Malignancy Index (RMI) >150 based on serum CA-125, ultrasound examinations and menopausal state, underwent PET/CT within 2 weeks prior to standard surgery/debulking of a pelvic tumor. Ten PET/CT features were identified and evaluated as predictors of cytoreduction in 54 patients with advanced ovarian cancer.
Results: Complete cytoreduction (no macroscopic residual disease) was achieved in 35% and optimal cytoreduction (<1 cm residual disease) was achieved in 56%. Using univariate analysis, predictors of incomplete cytoreduction were large bowel mesentery implants (LBMI) (P<0.003), pleural effusion (P<0.009), ascites (P<0.009) and peritoneal carcinosis (P<0.01). LBMI (P<0.03) and ascites (P<0.05) were also predictors of suboptimal cytoreduction. Using multivariate analysis, LBMI was the only independent predictor of incomplete cytoreduction (P=0.004) and no predictor of suboptimal cytoreduction was found.
Conclusion: PET/CT predictors of cytoreduction were found. But they should not be used to withhold patients form primary cytoreductive surgery. We suggest PET/CT as a supplementary image modality prior to surgery in primary OC patients whenever accurate and comprehensive preoperative evaluation of primary tumor and metastases is desired.