Clinical value of FDG-PET for recurrent renal cell carcinoma.

Objectives FDG-PET is not helpful in detection of primary renal cell carcinoma (RCC) due to its low sensitivity; however, the role for follow-up or suspected recurrence has not been fully evaluated. The purpose of this study was to assess diagnostic performance of FDG-PET for post-operative survey in patients with RCC.

Methods We reviewed 28 scans in 23 patients who had undergone FDG-PET scans between August 2000 and January 2008 after surgery for RCC. Based on final diagnoses obtained histologically or by clinical follow-up for at least 6 months, diagnostic accuracy of visual interpretation of PET was evaluated. Also, additional information over CT, influence on treatment decisions, and whether FDG uptake could be a predictor of survival were assessed.

Results Recurrence was confirmed in 21 of 28 cases histologically (n=15) or clinically (n=6). Overall sensitivity, specificity, and accuracy were 81%, 71%, and 79%, respectively. PET correctly detected local recurrence and metastases to peritoneum, bone, muscle and adrenal gland in all cases, but detection rate of metastases to brain, thyroid, liver, or kidney was low. Additional information was obtained in 6 cases (21%), with influence on therapeutic management in 3 cases (11%). Cumulative survival rates over 5 years in the PET-positive VS the PET-negative group were 46% VS 83%, (p=0.17).

Conclusions FDG-PET would be useful for postoperative surveillance in patients with RCC, although its impact on treatment decisions might be limited. Further investigations are needed to conclude whether PET can yield a prognostic value.