PET/CT in the evaluation of treatment response and follow-up in patients with ovarian carcinoma

Abstract

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Objectives: Ovarian cancer is the 4th most common gynecological malignancy but results in high mortality rate. Patients often are asymptomatic until late stage of disease. The purpose of this retrospective study is to evaluate the accuracy of PET/CT in patients referred for initial or re-staging of ovarian carcinoma. Methods: The authors analyzed 52 FDG PET/CT scans performed in 24 patients (mean age: 58.7 years old, range: 42-81) referred for initial staging (n=1 patients, 1 scan) and evaluation for recurrence (n=24, 51 scans) from ovarian carcinoma from 4/142004 to 10/6/2006. All patients fasted for at least four hours. Whole body PET/CT images were obtained with a PET/CT scanner (GE Discovery) approximately 75 minutes after administration of 10-15 mCi FDG. Oral contrast was given. Clinical outcomes were based on clinical follow up, conventional imaging (diagnostic CT and MRI), serum CA 125 levels and histopathology when available. Results: PET/CT demonstrates Disease (+) in 21 patients (48 scans), Disease (-) in 3 patients (4 scans). The overall sensitivity, specificity and accuracy of FDG PET/CT for follow-up of ovarian cancer is 94%, 100%, 96% respectively. Eleven patients have multiple PET/CT scans. Of these patients clinical outcome is as follows: 3 no recurrent disease, 1 progression of disease (PD), 2 partial response (PR), 2 both PR and PD, and 1 CR followed by relapse. THree false positive (FP) scans in 1 patient with concordant diagnostic CT likely due to microscopic disease. Conclusions: FDG PET/CT is extremely accurate in the evaluation of initial staging and suspected recurrence in patients with ovarian carcinoma.