Role of F-18 FDG PET/CT in the follow-up of asymptomatic renal cell carcinoma patients for postoperative surveillance: based on conditional survival analysis.

Abstract

This study investigated the clinical usefulness of F-18 fluorodeoxylucose (FDG) positron emission tomography/computed tomography (PET/CT) for postoperative surveillance in the RCC patients in terms of detectability of recurrence and radiation exposure. Three-hundred-and-forty- three RCC patients who underwent surgery and postoperative surveillance were retrospectively included. Conditional recurrent free survival (CRFS) was investigated and diagnostic performance of conventional imaging (CI) which include abdominopelvic CT or/and chest CT was compared to the FDG PET/CT. At a median follow-up of 4.3years (0.5-13.0years), thirty-nine patients (11.4%) developed recurrence. CRFS of the patients increased over time with greater increment in advanced stage. The sensitivity, specificity, positive-predictive value, negative-predictive value, and accuracy of FDG PET/CT were 92.3%, 97%, 80%, 99.0%, and 96.5% in detecting recurrence, while those values for CI were 89.7%, 97.7%, 83.3%, 98.7%, and 96.8%, respectively. There were no significant differences in these values between FDG PET/CT and CI (McNemar test, p = 0.581). The average radiation dose from FDG PET/CT was around 16.9 ± 3.08mSv at each follow-up time point. For early stage patients, the average radiation dose from CI was around 26.5 ± 8.57mSv at each follow-up time point, while this was about 33.0 ± 9.76mSv for advanced stage patients. FDG PET/CT exhibited good diagnostic performance in asymptomatic RCC patients after surgery, of a level comparable to that of CI, but with a lower radiation dose.