Abstract
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Objectives Ovarian cancer is a frequent malignancy in women with high mortality rate. Prognostic factors are essential to predict outcome and to plan an appropriate therapy.18F-FDG PET/CT showed promise in diagnosing, staging, detecting recurrences and monitoring treatment response. We now aim to establish Its prognostic role in the restaging process.
Methods Patients (n=168) affected by ovarian carcinoma underwent a restaging 18F-FDG PET/CT at least 6 months after surgery or chemotherapy. Local recurrences, nodal involvement and distant metastases were recorded. Dimensions, SUVmax and SUVmean were automatically calculated. Progression Free Survival (PFS) and Overall Survival (OS) were evaluated on a min.3 year-follow-up. Increased odd ratio was also assessed by testing all parameters associated to the lesions.
Results PFS was significantly longer in patients with a negative restaging study (3 years-PFS of 61%vs17% for positive pts, p<0.001). A negative study was also associated with a significantly higher OS rate (73% vs 40% at 3 years; 50% vs 18% at 5 years, p<0.001). A local recurrence or nodal involvement were associated with an increased risk of disease progression (HR= 1.8 times higher than negative studies), although only approaching statistical significance (p=0.09). The presence of distant metastasis increased risk of progression (HR: 2.4; p=0.003). No SUVmax or SUVmean thresholds were found to be predictive of a worse outcome in our population.
Conclusions 18F-FDG PET/CT has a prognostic value in predicting disease progression and mortality rate. An effective therapy might effectively rely on scintigraphic findings. Semi-quantitative data were not proven to predict disease progression.