Diffusion-weighted MRI, 11C-choline PET and 18F-fluorodeoxyglucose PET for predicting the Gleason score in prostate carcinoma.

OBJECTIVES

To evaluate the accuracy of transrectal ultrasound-guided (TRUS) biopsy, diffusion-weighted (DW) magnetic resonance imaging (MRI), (11)C-choline (CHOL) positron emission tomography (PET), and (18)F-fluorodeoxyglucose (FDG) PET in predicting the prostatectomy Gleason risk (GR).

METHODS

The study included 21 patients who underwent TRUS biopsy and multi-technique imaging before radical prostatectomy. Values from five different tests (TRUS biopsy, DW MRI, CHOL PET, FDG PET, and combined DW MRI/CHOL PET) were correlated with the prostatectomy GR using Spearman's ρ. Tests that were found to have significant correlations were used to classify patients into GR groups.

RESULTS

The following tests had significant correlations with prostatectomy GR: TRUS biopsy (ρ = 0.617, P = 0.003), DW MRI (ρ = -0.601, P = 0.004), and combined DW MRI/CHOL PET (ρ = -0.623, P = 0.003). CHOL PET alone and FDG PET only had weak correlations. The correct GR classification rates were 67% with TRUS biopsy, 67% with DW MRI, and 76% with combined DW MRI/CHOL PET.

CONCLUSIONS

DW MRI and combined DW MRI/CHOL PET have significant correlations and high rates of correct classification of the prostatectomy GR, the strength and accuracy of which are comparable with TRUS biopsy.

KEY POINTS

• Accurate determination of the Gleason score is essential for prostate cancer management. • DW MRI ± CHOL PET correlated significantly with prostatectomy Gleason score. • These correlations are similar to that between TRUS biopsy and prostatectomy.