PET scans for decision-making in metastatic renal cell carcinoma: a single-institution evaluation

Therapeutic decision-making in metastatic renal cell carcinoma (MRCC) is based on conventional radiological evaluation. Fluorodeoxyglucose positron emission tomography (FDG-PET) scans may modify this strategy.

Patients with MRCC for whom a therapeutic decision had been made underwent an FDG-PET scan in order to complete the standard radiological evaluation.

Twenty-four patients and 26 FDG-PET scans were eligible. In 18 patients, metastatic disease was evaluable on the computed tomography (CT) scan; the FDG-PET scan was positive in 16 patients and negative in 10. In 2 patients, the FDG-PET scan was positive while they were considered disease free on radiological evaluation. In 5 patients (20.8%), the previous therapeutic decision was changed. Thirteen patients had a pathological evaluation for 19 sites. One patient out of 13 had a false-positive FDG-PET scan, while 4 sites out of 6 were false-negative. The sensitivity was 75% (95% CI: 47.6-92.7) and the predictive positive value was 92.3% (95% CI: 64-99.8). With a median follow-up of 24 months, 3 patients developed new metastatic sites.

Our data suggest that, when positive, an FDG-PET scan may modify the decision made; when negative, it should not modify decision-making especially for surgery, owing to its sensitivity.