MRI-guided transurethral ultrasound ablation (TULSA) is a new tool for the highly accurate treatment of prostate cancer — without the usual side effects.
Although the 5 year survival rate with early detection and nonaggressive forms is 99%, 1 in 9 males will receive a diagnosis of prostate cancer at some point in their lives.
Currently, there are two common treatment options: surgical removal of the prostate and radiation therapy.
Although these are usually effective, they come with side effects, including incontinence, erectile dysfunction, and bowel issues. Now, however, researchers have devised a new and promising procedure utilizing therapeutic ultrasound guided by real time MRI.
TULSA offers enhanced precision and control in the treatment of both prostate cancer and enlarged prostate.
About the prostate
The prostate is an apricot-sized muscular gland that introduces prostatic fluid to the seminal vesicles at orgasm. This fluid protects sperm and enhances their mobility. Some of its compontents include enzymes, zinc, and citric acid.
Nerve tissues and muscle surround the prostate. This makes it quite difficult to precisely remove or target with radiation.
Although scientists have investigated other ultrasound systems, TULSA's employment of real time MRI promises greater accuracy than previously possible.
How does TULSA work?
The TULSA system has evolved over the past few years as a minimally invasive approach that can precisely target prostate tissue without adversely affecting nearby healthy tissue and muscle.
The procedure takes place during an MRI scan. This allows doctors to see what they are doing in exceptional detail.
The rod-shaped TULSA tool contains 10 ultrasound generators that apply heat. These can destroy, or ablate, prostate tissue. The doctor can control the individual ultrasound beams using software that continually optimizes their shape, strength, and targeting.
According to study co-author Steven S. Raman, "Unlike with other ultrasound systems on the market, [we] can monitor the ultrasound ablation process in real time and get immediate MRI feedback of the thermal dose and efficacy."
In the study, treatment times with TULSA averaged 51 minutes. The researchers treated the entire prostate in that time. "It's an outpatient procedure with minimal recovery time," says Raman.
The trials also validate the use of MRI as a post-TULSA diagnostic tool, since it proved 93–96% accurate in detecting the absence of cancer at 1 year checkups.
The results of TULSA tests
For the TULSA-PRO ablation clinical trial, the researchers recruited 115 males. The participants had a median age of 65 and a low or intermediate risk of nonmetastasized prostate cancer.
TULSA led to dramatic improvements in prostate size, from 39 cubic centimeters (cc) to 3.8 cc at 1 year after treatment. In 80% of the participants, the method eliminated clinically significant cancer.
Of the final cohort of 111 males, 72 (65%) were cancer-free in biopsies that health professionals conducted a year later. Their levels of prostate-specific antigen — which indicate the presence or absence of prostate cancer — dropped by an average of 95%.
Raman adds that there was "a dramatic reduction of over 90% in prostate volume and low rates of impotence with almost no incontinence."
Officials in Europe have already approved TULSA, and Raman is hopeful that approval in the United States will follow if further testing confirms the study's findings.
If so, TULSA could become a valuable tool for prostate issues in two ways.
"There are two very unique things about this system," points out Raman.
"First, you can control with much more finesse where you're going to treat, preserving continence and sexual function. Second, you can do this for both diffuse and localized prostate cancer and benign diseases, including benign hyperplasia."
Steven S. Raman
With prostate cancer and enlarged prostate being such common occurrences, TULSA's improved efficacy with fewer side effects will provide a welcome alternative.