Use of (18)F-FDG PET/CT in the preoperative evaluation of patients diagnosed with peritoneal carcinomatosis of ovarian origin, candidates to cytoreduction and hipec. A pending issue.

ABSTRACT

PURPOSE: To evaluate the clinical usefulness of the results obtained with (18)F-FDG PET/CT in relation to CT in the preoperative staging of patients with peritoneal carcinomatosis secondary to primary or recurrent ovarian cancer candidates to cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC). MATERIAL AND METHODS: A retrospective study comparing the results obtained with CT and (18)F-FDG PET/CT in the preoperative evaluation of a series of 59 patients was performed. In all patients the peritoneal carcinomatosis index (PCI) was determined by preoperative radiological CT and 18F-FDG PET/CT and compared with surgical PCI, which was considered as reference. RESULTS: Of the 59 patients studied, in 55 peritoneal carcinomatosis presences were confirmed (4 patients had complete responses to neoadjuvant chemotherapy). The mean surgical, CT and 18F-FDG PET/CT PCI was 9.46±7.70, 3.69±3.96 and 2.25±1.02, respectively. In the global disease detection, CT showed a higher positive likelihood ratio (LR+) than (18)F-FDG PET/CT (15.3, 95% CI 8.35-28.04 vs. 3.47, 95% CI 3.36-5.11) and a lower negative likelihood ratio (LR-) than 18F-FDG PET/CT (0.67, 95% CI 0.61-0.73 vs. 0.82, 95% CI 0.76-0.88). In every region of the abdomen the CT showed a greater LR+ than 18F-FDG PET/CT and a lower LR- than 18F-FDG PET/CT. CONCLUSIONS: CT showed the best diagnostic results compared to (18)F-FDG PET/CT to confirme the presence of peritoneal disease. The lower performance of the (18)F-FDG PET/CT suggests that the main utility of (18)F-FDG PET/CT is to evaluate a possible metastatic extraperitoneal spread of the disease.