In-bore MR prostate biopsy - initial experience

The introduction of multiparametric MRI (mpMRI) has been a breakthrough in the diagnosis of noninvasive clinically significant prostate cancer. Currently, MR-guided prostate biopsy (in-bore biopsy) is the only biopsy method that uses real-time MRI in patients with suspected prostate cancer. The aim of the study was a retrospective analysis of the correlation between MRI results and histological findings of prostate samples suspected of malignancy, which were taken during MRI-guided biopsy.

Thirty-nine patients with 57 lesion biopsies were enrolled in the study. Patients were aged 48-84 years (mean age 67.2 ± 9.4 years).

Cancer was histologically confirmed in 24 lesions, including primary cancer in 14 lesions and local recurrence in 10 lesions. Cancer was not detected in the remaining lesions (n = 33). Malignancy was confirmed in 90% of lesions previously reported as PI-RADS 5. Only one Prostate Imaging and Reporting and Data System (PI-RADS 5) lesion was histologically negative (prostatitis). Cancer was detected in 50% of lesions defined as PI-RADS 4. Cancer cells were not found in any of 23 lesions defined as PI-RADS 3 (53.5%). Most of the lesions assessed as PI-RADS 3 were located in the transitional zone (n = 19). Only four PI-RADS 3 lesions were found in the peripheral zone. Large lesions or lesions feasible for cognitive TRUS biopsy were not referred for MRI biopsy, which resulted in a higher proportion of lesions assessed as PI-RADS 3. Fourteen lesions suspected of local recurrence were assessed in our study. Cancer was found in approximately 72% of the lesions.

Performing prostate biopsy under the guidance of real-time MRI allows precise collection of material for histological examination (even from a very small lesion). As a result, both primary cancer and local recurrence after previous radiotherapy of prostate cancer can be confirmed.