Significance of (18)F-FDG PET/CT in Characterization of Equivocal Lesions in High-Risk Testicular Carcinoma in Restaging Setting

OBJECTIVES: The present study aims to evaluate the role of Positron emission tomography (PET) -computed tomography (CT) with (18)F-fluorodeoxyglucose ((18)F-FDG) in the restaging of high-risk testicular cancer. METHODS: Forty-five patients (mean age of 38.1±11.3 years and range 23-81 years) with testicular carcinoma, underwent (18)F-FDG PET-CT during their clinical course were prospectively selected. PET positivity was defined as a site of abnormal (18)F-FDG uptake in tissue histologically proven or clinically or radiographically suspected to represent tissue involvement. The sites of disease were characterized as either nodal or extranodal. All patients were followed-up for at least 12 months with a diagnostic and/or functional imaging modality. RESULTS: Of the 45 patients 38 (84%) patient presented with seminoma and 7 (16%) were Non-seminomatous germ cell tumors. Analysis of secondary disease spectrum showed nodal involvement in 65%, osseous involvement in 23% and mixed visceral/soft tissue lesions in 12% of patients. Nineteen (42%) were negative for any metastatic disease. All negative patients remain disease free in the follow-up of one year. Out of the positive 26/45 patients, PET-CT showed progressive disease in 3/26, stable disease 1/26 and partial response in 2/26 and complete metabolic resolution in 20/26 patients. (18)F-FDG PET-CT was able to characterize all patients leading to significant change of primary decision of wait and watch to go for treatment and vice versa. CONCLUSION: (18)F-FDG PET-CT scan is potentially an excellent tool for characterization of equivocal lesions on CT scan in the restaging settings and follow up of high-risk testicular cancer patients.