transperineal mapping biopsy Archives

Does the Radiation Dose Required to Eradicate Local Disease Differ by Gleason Grade Group?

by Nelson N. Stone, MD | Jun 2021

Nelson N. Stone, MD, Professor of Urology, Radiation Oncology, and Oncological Sciences at the Icahn School of Medicine at Mount Sinai and at the Derald H. Ruttenberg Cancer Center at Mount Sinai, discusses the radiation dose requirements for local disease eradication and the implications for focal therapy. He presents studies of external vema radiation and brachytherapy, which both showed that as the radiation dose increased the likelihood of a positive biopsy decreased two years post treatment. Dr. Stone concludes that it does not matter what type of disease the patient has, it matters how much radiation is used to get rid of the disease. Longer term follow up is needed to see the impact of radiation doses. Post-irradiation biopsies imply that a BED of over 240 Gy can eradicate all prostate cancer. If a tumor is small then there is a potential for a high dose of radiation just to the affected regions. Larger tumors or cases with extensive multifocality will require a full dose treatment with a full or partial implant.

Does Anatomic Rectal Displacement Improve Dosimetry and Reduce Injury?

by Richard G. Stock, MD | May 2021

Richard G. Stock, MD, Professor of Radiation Oncology and Director of Genitourinary Radiation Oncology at the Icahn School of Medicine at Mount Sinai in New York City, reviews the literature on rectal displacement to prevent damage to the rectum from prostate brachytherapy and external beam radiation therapy (EBRT). First, he summarizes the findings of numerous papers from the past 20 years that have identified a relationship between the dose and volume of radiation and damage to the rectum such as bleeding and mucosal changes. The more radiation reaches the rectum, and the greater the surface area of the rectum affected, the more likely patients will experience adverse effects, including greater levels of morbidity. Dr. Stock then considers how the rectum can be spared, focusing on the evidence around rectal spacers such as endorectal balloons and hydrogel spacers such as SpaceOAR. He explains that numerous studies demonstrate that by inserting a physical barrier between the rectum and the prostate, the rectum is kept separate from the radiation and therefore receives a lower rate of toxicity. Dr. Stock notes that patients experience more rectal discomfort with spacers like SpaceOAR than without, but suggests that the reduction of significant issues such as bleeding outweigh the downsides. He concludes by discussing a recent study of his which found that SpaceOAR can be inserted before brachytherapy and EBRT.

Freehand Transperineal Prostate Biopsy Under Local Anesthesia

by Michael A. Gorin, MD | May 2021

Michael A. Gorin, MD, a urologist with Urology Associates of Cumberland, Maryland, explains the benefits of transperineal prostate biopsy compared to the transrectal approach for prostate cancer patients. First, he discusses the complications of transrectal biopsy, specifically infection risk, and demonstrates how the transperineal approach can decrease this risk without contributing to antibiotic resistance. He then explains how transperineal biopsy aids in improved detection and cancer upgrading. Dr. Gorin goes on to review transperineal biopsy methods, including the use of the Precisionpoint Transperineal access system. Finally, he summarizes block techniques and biopsy templates for freehand transperineal prostate biopsy under local anesthesia in the outpatient setting.

Can One Biopsy Event Determine Type and Amount of Focal Therapy Treatment?

by Nelson N. Stone, MD | May 2021

Nelson N. Stone, MD, Professor of Urology, Radiation Oncology, and Oncological Sciences at the Icahn School of Medicine at Mount Sinai and at the Derald H. Ruttenberg Cancer Center at Mount Sinai argues for the use of Transperineal Mapping Biopsy (TPMB), and against the use of strict criteria and cursory cancer identification methods for finding Focal Therapy eligible patients. He expresses a clinical need for a process that identifies Focal Therapy candidates and lists which portions of the prostate require treatment. He suggests that TPMB can fulfill these goals. Dr. Stone summarizes a review of the evidence for using focal therapy for the treatment of prostate cancer and found that despite at least 50% of patients being Focal Therapy eligible only a minority of patients actually receive the therapy. He critiques a study on Focal Therapy eligibility determined by MRI/US fusion biopsy on the basis of using too strict of criteria for selecting patients and in consideration of the possibility of missing many patients due to not using a biopsy. Dr. Stone discusses several other studies that depict MRI as unreliable in accurately identifying Focal Therapy patients compared to TPMP due to the lower accuracy of MRI across the prostate.