V4-09: Transperineal prostate biopsy with new mapping software

Video

Introductions and Objectives
To demonstrate new mapping software designed to improve accuracy of transperineal prostate biopsy (TPMB) and focused therapy (FT).

Methods
TPMB has been shown to greatly increase the detection of additional lesions over transrectal biopsy in patients with low volume disease or prior negative biopsy. However tracking the location of the positive biopsy sites is limited because no software exists that records their locations. We developed a software program that can detect a lesion of 5 mm or greater with 95% accuracy. The software also allows the physician to incorporate the pathology results at the positive biopsy sites creating a 2 and 3-dimensional model which can then be incorporated into a focused therapy treatment planning system. The patient is placed under anesthesia in the lithotomy position. Prostate images are acquired using the mapping software via a video card linked to the US output to create the 3D model. A biopsy plan is generated at 5 mm intervals in transverse which can be adjusted based on core length, distance from capsule and urethra and in-line needle number (for cores requiring multiple punctures for prostate length>2cm). The physician starts the biopsy procedure at needle #1 (upper right lateral of prostate). The virtual needle can be moved so it overlies the actual puncture needle in the gland. Imaging is switched to sagittal, the needle is brought back to apex and fired. The virtual needle is moved to be aligned with the biopsy needle after it takes the core. Biopsies are taken from left to right working from the top row down to the most posterior of the gland. The entire procedure takes 45-60 min. Each specimen is inked at the base end so the pathologist can report the presence of cancer, its distance from the ink and the length of the tumor. A 3D model of the gland and the lesion size and locations are generated.

Results
9 men with a mean age of 59.3 years (range 47-66), mean PSA of 4.3 ng/ml (range 2-7) and mean prostate volume of 48.5 cc (range 29-73) underwent 3D mapping using the new software. 6/9 had a prior biopsy of which 4 were positive for 1 or 2 cores of focal disease. After mapping 7/9 (77.8%) were positive. A mean of 71.8 cores (range 43-127) were taken and a mean of 4.4 (range 1-12) had prostate cancer. Of the 7 positive case, 4 were bilateral. One case with a single focus of Gleason 7 was negative with 3D mapping. 2 patients decided on focal treatment, 2 brachytherapy, 1 radical prostatectomy, 1 surveillance and 2 are undecided.

Conclusions
3D mapping provides a new method to assess prostate gland pathology. FT can be accurately performed using the 3D roadmap to ablate individual lesions.

Funding: 3DBiopsy LLC