The sensitivity of [11C]choline PET/CT to localize prostate cancer depends on the tumor configuration.

PURPOSE: To evaluate the dependency of the sensitivity of [(11)C]choline positron emission tomography/computed tomography (PET/CT) for detecting and localizing primary prostate cancer (PCa) on tumor configuration in the histologic specimen.

EXPERIMENTAL DESIGN: Forty-three patients with biopsy-proven PCa were included. They underwent radical prostatectomy within 31 days after [(11)C]choline PET/CT. The transaxial image slices and the histologic specimens were analyzed by comparing the respective slices. Maximum standardized uptake values (SUV(max)) were calculated in each segment and correlated with histopathology. The tumor configuration in the histologic specimen was grouped as: I, unifocal; II, multifocal; III, rind-like shaped; IV, size <5 mm. Data analysis included the investigation of detection of PCa by SUV(max), the assessment of the influence of potential contributing factors on tumor prediction, and the evaluation of whether SUV could discriminate cancer tissue from benign prostate hyperplasia (BPH), prostatitis, HGPIN (high-grade prostate intraepithelial neoplasm), or normal prostate tissue. General estimation equation models were used for statistical analysis.

RESULTS: Tumor configuration in histology was classified as I in 21 patients, as II in 9, as III in 5, and as IV in 8. The prostate segment involved by cancer is identified in 79% of the patients. SUV(max) was located in the same side of the prostate in 95% of patients. Tumor configuration was the only factor significantly negatively influencing tumor prediction (P < 0.001). PCa-SUV(max) (median SUV(max) = 4.9) was not significantly different from BPH-SUV (median SUV(max) = 4.5) and prostatitis-SUV (median SUV(max) = 3.9), P = 0.102 and P = 0.054, respectively.

CONCLUSIONS: The detection and localization of PCa in the prostate with [(11)C]choline PET/CT is impaired by tumor configuration. Additionally, in our patient population, PCa tissue could not be distinguished from benign pathologies in the prostate.