Objective: Diagnostic (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) is an established method for detecting ovarian cancer. However, there is no established method to detect hypermetabolic tumor intraoperatively to evaluate disease extent and assure complete resection. We describe an innovative approach for intraoperative tumor localization and verification of tumor resection utilizing (18)F-FDG for perioperative PET/CT imaging and intraoperative gamma probe detection in ovarian cancer.
Methods: Three patients with recurrent ovarian cancer in the lymph nodes were evaluated. Diagnostic (18)F-FDG PET/CT was performed before surgery to establish the disease location. Preoperatively, (18)F-FDG was injected intravenously. Intraoperatively, tumors were localized with a handheld gamma probe. Postoperatively, resected tumors were scanned with a specimen PET/CT to confirm metabolic activity in those specimens.
Results: All patients had recurrent epithelial ovarian cancer with groin or retroperitoneal lymph node metastasis diagnosed with PET/CT. In two patients, intraoperative gamma probe detection, specimen PET/CT, and postoperative PET/CT verified complete resection of the clinical and hypermetabolic lesions (in one case, the extent of disease was not fully apparent intraoperatively by gross palpation or inspection). The other patient was demonstrated to have extensive, unresectable disease in the porta hepatis and celiac axis, much of which was recognized only with the intraoperative gamma probe and not with the initial intraoperative survey.
Conclusions: Perioperative PET/CT imaging with intraoperative detection using a gamma probe following a single (18)F-FDG injection dose is feasible, establishes the location and extent of disease, and confirms a complete cytoreduction for recurrent ovarian cancer.