Recurrent renal cell carcinoma: clinical and prognostic value of FDG PET/CT.
OBJECTIVE
The purpose of our study was 1) to evaluate the diagnostic performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), 2) to assess the impact of FDG PET/CT on treatment decision-making, and 3) to estimate the prognostic value of FDG PET/CT in the restaging process among patients with renal cell carcinoma (RCC).


METHODS
From the FDG PET/CT databases of San Raffaele Hospital in Milan, Italy, and the Veneto Institute of Oncology in Padua, Italy, we selected 104 patients with a certain diagnosis of RCC after surgery, and for whom at least 24 months of post-surgical FDG PET/CT, clinical, and instrumental follow-up data was available. The sensitivity and specificity of FDG PET/CT were assessed by histology and/or other imaging as standard of reference. Progression-free survival (PFS) and overall survival (OS) were computed using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards models were used to identify predictors of outcome.


RESULTS
FDG PET/CT resulted in a positive diagnosis in 58 patients and a negative diagnosis in 46 patients. Sensitivity and specificity were 74% and 80%, respectively. FDG PET/CT findings influenced therapeutic management in 45/104 cases (43%). After a median follow-up period of 37 months (± standard deviation 12.9), 51 (49%) patients had recurrence of disease, and 26 (25%) had died. In analysis of OS, positive versus negative FDG PET/CT was associated with worse cumulative survival rates over a 5-year period (19% vs. 69%, respectively; p <0.05). Similarly, a positive FDG PET/CT correlated with a lower 3-year PFS rate. In addition, univariate and multivariate analysis revealed that a positive scan, alone or in combination with disease stage III-IV or nuclear grading 3-4, was associated with high risk of progression (multivariate analysis = hazard ratios [HRs] of 4.01, 3.7, and 2.8, respectively; all p < 0.05).


CONCLUSIONS
FDG PET/CT is a valuable tool both in treatment decision-making and for predicting survival and progression in patients affected by RCC.
Nuclear Medicine Department, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Pierpaolo
P
Alongi
Nuclear Medicine Department, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Maria
M
Picchio
Department of Oncological and Surgical Sciences, Urology Clinic, University of Padua, Padua, Italy.
Fabio
F
Zattoni
University of Milano-Bicocca, Milan, Italy.
Marianna
M
Spallino
Nuclear Medicine Department, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Luigi
L
Gianolli
Radiotherapy and Nuclear Medicine Unit, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy, Gattamelata Street, 64, Padua, Italy.
Giorgio
G
Saladini
Radiotherapy and Nuclear Medicine Unit, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy, Gattamelata Street, 64, Padua, Italy. laura.evangelista@ioveneto.it.
Laura
L
Evangelista
D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging*; D003657:Decision Making; D020000:Decision Support Systems, Clinical; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000737:chemistry; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011379:Prognosis; D016016:Proportional Hazards Models; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
FDG PET/CT; Multivariate analysis; Prognosis; Recurrence; Renal cell carcinoma