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Transperineal Fusion Prostate Biopsy Increases Diagnostic Accuracy

In This Article

  • Most prostate cancers are not fatal, but early diagnosis of serious prostate cancer can save lives
  • Current biopsy approaches are uncomfortable, carry patient safety risks and present challenges in collecting samples from some areas of the prostate
  • The transperineal fusion method strategically targets suspicious areas, is safe and comfortable, and can be done in an office setting

Physicians at Massachusetts General Hospital have pioneered office-based transperineal fusion biopsy, a sophisticated prostate cancer diagnostic procedure. This innovation addresses key challenges associated with the standard biopsy technique, including infection risk, patient discomfort and accurate targeting of key prostate gland areas.

Douglas Dahl, MD, chief of the Division of Urologic Oncology at the Mass General Cancer Center, and Mass General Urologist Michelle Kim, MD, PhD, are leaders in the procedure, and are working together to implement refinements to the process that will protect at-risk patients.

"Transperineal fusion biopsy is safe, relatively comfortable and highly targeted," says Dr. Dahl. "It's an important evolution in our comprehensive strategy to improve the patient experience while accurately identifying serious prostate cancers."

"Our approach protects patients who have bleeding complications, inflammatory bowel disease or are otherwise at high risk," Dr. Kim says. "And we can better target tumors in hard-to-reach locations, providing earlier diagnoses."

Prostate Cancer Screening and Diagnosis

Prostate cancer is the second most common cancer in men, with nearly 175,000 cases diagnosed each year. However, 90% of diagnoses involve clinically indolent cancers that are not likely to cause significant harm during a man's life.

Most men between the ages of 50 and 69 undergo periodic screening by digital rectal exam (DRE), or prostate-specific antigen (PSA) blood testing. Men with palpable irregularities or elevated PSA levels may be referred for a biopsy, but a biopsy is not necessary in all cases. Dr. Dahl and Dr. Kim's team previously developed a highly refined algorithm that uses PSA and biomarker tests to ensure only men with serious risk factors are referred for biopsy.

A standard prostate biopsy is conducted with a transrectal approach, which accesses the prostate by inserting a needle through the rectum. This method has risks including:

  • Infection: The needle can introduce intestinal bacteria into the bloodstream, including fluoroquinolone-resistant organisms
  • Injury: Men can experience rectal tears and associated bleeding
  • Discomfort: Fear of infection and other complications deters some men from testing, potentially leading to missed diagnoses
  • Inaccurate sampling: The standard method may not sufficiently identify samples needed from the anterior prostate and other areas, resulting in false-negative diagnoses

As Dr. Kim explains, transperineal fusion biopsy has the dual benefit of efficacy and reduced risk. "Studies have confirmed that the fusion procedure provides equivalent results," she says.

Increased Accuracy, Reduced Risk

The transperineal fusion biopsy procedure begins with T2-weighted, diffusion-weighted and dynamic contrast MRI sequences. The clarity of the MRI scan serves to:

  • Resolve suspicious lesions: Physicians can sometimes rule out cancer based on the MRI, allowing patients to avoid unnecessary biopsies
  • Inform biopsy planning: MRI data enables identification and categorization of lesions for robust and accurate sampling

The biopsy is completed in the physician's office with local anesthesia. The physician inserts the biopsy needle through the perineum and into the prostate gland. The benefits of the transperineal approach include:

  • Avoiding contact with harmful bacteria: Insertion through transperineal skin ensures no intestinal bacteria are introduced into the body, preventing several infection risks
  • Eliminating contact with the rectal wall: The needle will not contact the rectal wall, avoiding tears and subsequent pain and infection
  • Allowing access along the longitudinal axis of the prostate: The angle of approach allows more accurate sampling of the anterior section and base of the prostate, lowering the risk of a missed diagnosis

The physician uses a transrectal ultrasound (TRUS) to direct the biopsy needle. Sophisticated software layers the previously collected MRI results over the real-time TRUS images. The combined data provides the clarity of MRI data with the flexibility of ultrasound imaging, allowing:

  • Targeted sample collection: With clear information about the location and size of lesions, physicians can sample various parts of the lesion, increasing accuracy and avoiding repeat biopsy sessions
  • Applied physician expertise: Physicians have the flexibility to refine the MRI sampling plan based on their real-time observations, resulting in a thorough and individualized procedure

Promising Studies

Early results indicate that transperineal fusion biopsy is as accurate as traditional prostate biopsy and yields better recovery for patients. "We're seeing equivalent rates of cancer detection," says Dr. Kim. "And most of our patients go back to their daily activities after their procedure, reporting minimal and tolerable perineal discomfort."

Recent studies bear out Mass General's patient safety and comfort findings. The most serious infection, sepsis, has not been identified in transperineal fusion patients, in comparison to a rate of about 3% in transrectal procedures. Almost 90% of men who undergo the new biopsy indicate they would recommend the procedure to others.

Dr. Dahl anticipates continued evolution in prostate cancer identification and diagnosis, with innovations such as inhaled nitrous to shorten anesthesia time and a potential robotic system in the future.

"Our continued innovation is part of a comprehensive program that provides the tools to target serious illness at the earliest stage and avoid invasive procedures in patients who don't have significant risk," he says.

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