Transrectal Prostate Biopsy and Fiducial Marker Placement in a Standard 1.5T Magnetic Resonance Imaging Scanner

Abstract

Purpose:We investigated the accuracy and feasibility of a system that provides transrectal needle access to the prostate concurrent with 1.5 Tesla MRI which previously has not been possible. Materials and Methods: In 5 patients with previously diagnosed prostate cancer, MRI guided intraprostatic placement of gold fiducial markers (4 procedures) and/or prostate biopsy (3 procedures) was performed using local anesthesia. Results: Mean procedure duration was 76 minutes and all patients tolerated the intervention well. Procedure related adverse events included self-limited hematuria and hematochezia following 3 of 8 procedures (all resolved in less than 1 week). Mean needle placement accuracy was 1.9 mm for the fiducial marker placement studies and 1.8 mm for the biopsy procedures. Mean fiducial marker placement accuracy was 4.8 mm and the mean fiducial marker placement accuracy transverse to the needle direction was 2.6 mm. All patients who underwent the procedure were able to complete their course of radiotherapy without delay or complication. Conclusions: While studies of clinical usefulness are warranted, transrectal 1.5 T MRI guided prostate biopsy and fiducial marker placement is feasible using this system, providing new opportunities for image guided diagnostic and therapeutic prostate interventions.

An MRI-Compatible Robotic System With Hybrid Tracking for MRI-Guided Prostate Intervention

“…The errors and procedure times with the APT II system compare favorably to reported results (average in-plane biopsy error 2.7 mm and average procedure times of 76 min) that we achieved with the active tracking method in clinical trials using the APT-I system [1], [3]. The hybrid tracking method allows the APT II system to be used on any MRI scanner without extensive systems integration and calibration.…”

“…In [1], [3], [4], [29], [30], [34], and [35], the authors reported the development and clinical evaluation of an MRI-guided system for transrectal prostate biopsies, therapy injection, and marker placements. The system, called the APT I, contains a single-loop MRI endorectal imaging coil and employs active tracking for device localization.…”

MRI-Safe Robot for Endorectal Prostate Biopsy

“…A manually operated version of this device has been used in clinical trials [11, 34]. Manually operated devices [10] have been the first to clinical tests and had major contributions to test the feasibility of interventional MRI.…”

“…A few groups investigated the use of manually operated needle-guide devices in the MRI scanner [10, 11]. But these manual devices may be difficult to operate due to the limited access within the scanner and table movements are required to access the patient.…”

“…Hitherto, very few interventional MRI-guided prostate biopsy devices have been tested clinically [11, 28] in very few patients. Yet, these have shown the feasibility of interventional MRI and CSR biopsy targeting, and that these may selectively improve the detection of significant prostate cancer.…”