LAUSR

Introduction/Background In locally advanced ovarian cancer the primary treatment is debulking surgery followed by chemotherapy. Surgery is recommended in patients who can be debulked upfront to no residual tumour. Therefore, there are some specific criteria against primary surgical approach. In case of inoperable disease, neoadjuvant chemotherapy with interval surgery should be planned. The aim of this study is to evaluate the capability of FDG-PET/CT to assess abdominal resectability in advanced ovarian cancer, before surgery. Methodology Unicenter, restrospective, observational study included 35 patients (age 63.11, range 40–82 years) with clinical and radiological suspicion of primary advanced ovarian cancer. All patients underwent contrast enhanced PET/CT before surgery. Based on criteria against surgical approach, patients were classified as resectable or non resectable. Sensitivity, specificity, NPV, PPV and accuracy for PET/CT to predict complete surgical resectability were calculated. Results Thirty-one patients were concordant (18 patients were considered resectables by PET/CT and surgery, 13 patients were considered non resectables by PET/CT and surgery). Only 4 patients were discordant: 1 patient presented inoperable milliary carcinomatosis, not visible by PET/CT. The other 3 patients were finally resectables but it seems not by PET/CT (large and diffuse carcinomatosis of the small bowel or extense involvement of superior abdomen). For detection of abdominal resectability, PET/CT presented a sensitivity of 85.7% (95% CI: 64–97), specificity 92.8%(95% CI: 66–100), NPV 81.2%(95% CI: 54–96), PPV 94.7%(95% CI: 74–100) and accuracy of 88.57%(95% CI: 73–96). PET/CT also revealed extrabdominal distant metastases in 9/35 patients (29%), mainly represented by supradiaphragmatic lymph nodes (8/9 patients), associated with additional metastases in pleura and/or liver. Conclusion In locally advanced ovarian cancer, PET/CT had good results in assessment of surgical abdominal resectability, especially in terms of specificity, PPV and accuracy. PET/CT could be helpful in patients with questionable initial terapeutic decision, due to its ability to detect additional unsuspected extraabdominal disease. Disclosure Nothing to disclose.