3D-Mapping Biopsy Can Impact Prostate Cancer Management: Presented at SIR

by Kristina Rebelo | DocGuide.com | 03.12.2009

SAN DIEGO -- March 12, 2009 -- Transperineal 3-dimensional prostate-mapping biopsy (3D-PMB) provides superior cancer-staging information when compared with the more traditional ultrasound or transrectal ultrasound (TRUS) when choosing candidates for focal prostate cancer therapy, a researcher reported here at the Society of Interventional Radiology (SIR) 34th Annual Scientific Meeting.

Since the stage, grade, and extent of prostate cancer determines the approach to treatment -- watchful waiting, hormonal therapy prior to radiation therapy, or focal therapy -- more detailed information on tumour characteristics can help the patient and physician with the decision on the best potential therapy.

Previous studies have shown that TRUS biopsy poorly reflects the true disease extent in the patient, making treatment decisions difficult.

With 3D mapping, a grid is placed over the perineum that allows an interventional radiologist to accurately map the location of each biopsy core that is removed; the cores are taken through the skin, allowing numerous more cores to be removed (50 vs 10-12 via TRUS). This grid also allows the interventional radiologist to cryoablate the tumour, sparing the prostate gland itself.

"A failure turns back into success and that's the advantage of doing focal therapy," said lead author and coinvestigator Gary Onik, MD, University of Central Florida Medical School, Celebration Health Florida Hospital, Center for Safer Prostate Cancer Therapy, Orlando, Florida. "With the 3D-PMB method, there are no failures and there is low risk."

Dr. Onik and colleagues conducted tumour-restaging analyses using the 3D-PMB technique in 180 patients with unilateral cancer who had previous positive, 1-sided TRUS biopsy and were considering conservative management. Biopsies were taken every 5 mm throughout the volume of the prostate. Specimen coordinate labelling allowed accurate reconstruction of the tumour location.

According to the study results, presented on March 11, 3D-PMB helped obtain a median of 50 cores (SD +-20.61) per patient.

The 3D-PMB results showed that 110 patients had positive results bilaterally (61.1%); 41 patients had Gleason scores of 7 or higher (22.7%); and 36 patients had negative results.

Complications of 3D-PMB were self-limited and included 14 patients (7.7%) who required short-term indwelling catheter drainage and 2 with haematuria; 1 required overnight bladder irrigation.

It was determined that 70% of patients potentially would have had their treatment plan changed as a result of new information provided by 3D-PMB results.

Low rates of morbidity included haematuria (1.2%) and retention (7%).

Dr. Onik said that based on the findings of this study, there is an obligation for the medical community to do further studies of 3D-PMB.

[Presentation title: 3D Prostate Mapping Biopsy Has a Potentially Significant Impact on Prostate Cancer Management. Abstract 198]

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