The role of prostate-specific antigen and multiparametric magnetic resonance imaging in the diagnosis of granulomatous prostatitis induced by intravesical Bacillus Calmette-Guérin vaccine therapy in patients with nonmuscle invasive bladder cancer.

Abstract

This study aimed to evaluate the role of serum prostate-specific antigen (PSA) levels and multiparametric magnetic resonance imaging (mpMRI) in the diagnosis of granulomatous prostatitis (GP) induced by intravesical Bacillus Calmette-Guérin vaccine (BCG) therapy in patients with nonmuscle invasive bladder cancer (NMIBC). We retrospectively analyzed eight patients with bladder cancer who underwent intravesical BCG therapy after transurethral resection of bladder tumor (TURBt) cancer. All these eight patients received 12-core transrectal ultrasound-guided prostate systemic biopsies. Clinical data on PSA with T1-weighted imaging (T1WI), T2WI, diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) on mpMRI were enrolled in the study. H and E and acid-fast staining was performed to pathologically prove GP. Four of all eight cases were above 4 ng/ml total PSA (tPSA) levels and four cases were within normal ranges, while free PSA/tPSA levels decreased to lower than 16% in all patients. Every patient had hard prostatic nodules through digital rectal examination (DRE). All characters of prostate mpMRI did not show signal intensity (SI) of prostate cancer before BCG therapy but showed abnormal signals after BCG therapy. All nodular lesions showed equal SI on T1WI, lower SI on T2WI, higher SI on DWI, and lower SI on ADC after BCG therapy. Pathologic results were GP and acid-fast staining outcomes were positive in all biopsies. Perioperative serum PSA levels, prostate magnetic resonance imaging, and DRE may help in the diagnosis of GP induced by intravesical BCG therapy. In general, male patients with middle- and high-risk NMIBC are recommended to undertake DRE, PSA, and prostate mpMRI, if possible, before and after TURBt."