FDG PET/CT in Ovarian Cancer (POCA)

Ovarian Cancer (OC) is the leading cause of gynecologic cancer–related deaths and the fifth most frequent cause of cancer mortality in women (5%) following lungs (25%), colon-rectum (14%), breast (8%), and pancreatic (7%) cancers (R[GF1] ). OC primarily differ on the histologic type the majority are: ovarian, fallopian tubes, and primary peritoneum carcinomas.
OC spreads via three different routes: the peritoneum, the lymphatic system, and the bloodstream.
The standard treatment of OC is debulking surgery followed by systemic therapy. The complete resection of tumor implants provides the best survival rates; postsurgical residual tumor is one of the most important negative prognostic factors (R[GF2] ). For these reasons, early detection of sites of tumor spread is highly important (R[GF3] ). Unfortunately, most cases of OC are discovered when ascites or other signs of metastatic spread become clinically evident.
Although the role of 18F-FDG PET/CT in the staging of OC has not yet clearly established, several studies have shown promising results. 18F-FDG PET/CT may overcome some limitations of conventional imaging (essentially Transvaginal US (TVUS); Contrast-enhanced CT (ceCT) and MR imaging). 18F-FDG PET/CT might be useful for the assessment of retroperitoneal lymph nodes, and especially for detecting metastatic lymph nodes ranging from 5 mm to 9 mm in size that are not diagnosed with conventional images (R[GF4] ). Also, given its capability to detect distant metastases it might provide more accurate evaluation of disease extent, especially in those areas that are difficult to assess with CT and MR, such as some peritoneal reflections, the mediastinum, and the supraclavicular region (R[GF5] ). Currently, there are still conflicting data regarding the routine use of PET/CT in  staging of OC, more studies are required. Moreover, false-negative results tend to occur with small lesions and with diffuse peritoneal spread, whereas false-positive results may occur in the presence of inflammatory lymph nodes. At present 18F-FDG PET/CTis considered complementary to conventional imaging and surgical techniques for disease staging.
This CRP will focus on evaluating the diagnostic performances of ceCT and 18F-FDG PET/CT, with the goal of comparing the two procedures in the pre-surgical evaluation of peritoneal carcinomatosis in patients with ovarian cancer.