Karl Engelhard

Prostate biopsy in the supine position in a standard 1.5-T scanner under real time MR-imaging control using a MR-compatible endorectal biopsy device

Thirty-seven consecutive patients with elevated PSA levels and negative tumor prostate biopsies underwent a MR-guided prostate biopsy in a 1.5-T scanner in the supine position. After localization of suspected tumor areas using an endorectal coil and two body-phased array coils, the biopsy device was positioned without any repositioning of the patient. The biopsy device consisted of a mount, a ball joint, a positioning stage and an insertion stage with a needle guide, which was filled with a MR-visible fluid to control positioning of the needle using a balanced steady-state free precession sequence (TrueFISP) and a high-resolution turbo spin echo (T2-TSE) sequence. Core biopsies were taken manually in the magnet. The biopsy needle could be correctly positioned in all cases. Suspected lesions with a diameter ≥10xa0mm could be successfully punctured. Four to nine (mean =6) biopsies were taken per patient. In 14 patients, prostate cancer was confirmed at histology. Twenty-four biopsies positive for cancer were performed in 14 patients. A correct correlation was found between the site of biopsy and histology. MR-guided prostate biopsy can be effective in increasing primary positive tumor biopsy results in patients with a history of negative tumor TRUS-guided prostate biopsies.

Magnetic resonance image-guided biopsies with a high detection rate of prostate cancer.

Aim. To explore the potential of transrectal magnetic resonance image- (MRI-) guided biopsies of the prostate in a patient cohort with prior negative ultrasound guided biopsies. Patients and Methods. Ninety-six men with suspected prostate cancer underwent MRI-guided prostate biopsies under real-time imaging control in supine position. Results. Adenocarcinoma of the prostate was detected in 39 of 96 patients. For individual core biopsies, MRI yielded a sensitivity of 93.0% and a specificity of 94.4%. When stratifying patients according to the free-to-total prostate-specific antigen (PSA) ratio, the prostate cancer discovery rate was significantly higher in the group with ratios less than 0.15 (57.1%). Conclusion. MRI-guided biopsy of the prostate is a diagnostic option for patients with suspected prostate cancer and a history of repeatedly negative transrectal ultrasound-guided biopsies. Combined with the free-to-total PSA ratio, it is a highly effective method for detecting prostate cancer.

MRI-guided core biopsy of the prostate in the supine position--introduction of a simplified technique using large-bore magnet systems.

ObjectivesTo introduce a simplified technique for MRI-guided core biopsies (MRGB) of the prostate in the supine position using large-bore magnet systems.MethodsFifty men with a history of negative transrectal ultrasound-guided biopsies underwent MRGB in either a 1.5-T (13/50) or 3.0-T (37/50) wide-bore MRI unit. MRGBs were conducted with the patients in a supine position using a dedicated MR-compatible biopsy device.ResultsWe developed a dedicated positioning device for the supine position. Using this device, the biopsies were performed successfully in all patients. Apart from minor rectal bleeding, only one patient developed a major side effect (urosepsis). Histology revealed prostate cancer in 25/50 (50xa0%) patients.ConclusionsThe new technique appears feasible. Its major advantage is the more comfortable and patient-friendly supine position during the biopsy without the need to modify the MRI system’s patient table.Key Points• A novel positioning device for MRI-guided prostate biopsies has been developed.• Biopsies can be performed in the patient-friendly supine position.• The positioning device can be utilised without modifying the MRI’s patient table.