Diagnostic value of Integrated PET/MRI for Detection and Localization of Prostate Cancer: Comparative Study to Multiparametric MRI and PET/CT

Abstract

Purpose: To evaluate the diagnostic value of integrated PET/MRI compared with conventional multiparametric MRI and PET/CT for the detailed and accurate segmental detection/localization of prostate cancer.

Methods: Thirty-one patients who underwent integrated PET/MRI using 18F-choline and 18F-FDG with an integrated PET/MRI scanner followed by radical prostatectomy were included. The prostate was divided into 6 segments (sextants) according to anatomical landmarks. Three board-certified radiologists noted the presence and location of cancer in each sextant on four different image interpretation modalities in consensus (1, multiparametric MRI

2, integrated 18F-FDG PET/MRI

3, integrated 18F-choline PET/MRI

and 4, combined interpretation of 1 and 18F-FDG PET/CT). Sensitivity, specificity, accuracy, positive and negative predictive values, likelihood ratios, and diagnostic performance based on the DOR (diagnostic odds ratio) and NND (number needed to diagnose) were evaluated for each interpretation modality, using the pathologic result as the gold standard. Detection rates of seminal vesicle invasion and extracapsular invasion were also evaluated.

Results: Integrated 18F-choline PET/MRI showed significantly higher sensitivity than did multiparametric MRI in all patients and low Gleason score patients. Integrated 18F-choline PET/MRI and 18F-FDG PET/MRI showed similar sensitivity and specificity to combined interpretation of multiparametric MRI and 18F-FDG PET/CT. However, integrated 18F-choline PET/MRI showed the best diagnostic performance among the imaging modalities, regardless of Gleason score. Integrated 18F-choline PET/MRI showed higher sensitivity and diagnostic performance than did integrated 18F-FDG PET/MRI.

Conclusion: Integrated PET/MRI carried out using a dedicated integrated PET/MRI scanner provides superior accuracy and diagnostic value for detection/localization of prostate cancer. Generally, integrated 18F-choline PET/MRI shows better accuracy and diagnostic performance than does integrated 18F-FDG PET/MRI.