Laser heat may soon be an option to treat prostate cancer. Focal laser ablation, which is the precise application of heat via laser to a tumor, has been found both feasible and safe in men with intermediate risk prostate cancer.1
The recently published phase 1 study found no serious adverse events or change in urinary or sexual function at 6 months after the procedure. A laser fiber guided by magnetic resonance imaging (MRI) is inserted into cancerous tumors. The laser is then heated, destroying the cancerous tissue. The technique is known as MRI-guided focal laser ablation.
If MRI-guided focal laser ablation proves effective in further studies, especially using the new MRI-ultrasound fusion machine, the technique could improve treatment options and outcomes for men with prostate cancer, said Leonard Marks, MD, a professor of urology and director of the University of California at Los Angeles Active Surveillance Program, and senior author of this study. Historically, prostate cancer is treated with surgery and radiation, which can result in serious side effects such as erectile dysfunction and urinary incontinence.
“Our feeling was that if you can see prostate cancer using the fusion MRI and can put a needle in the spot to biopsy it, why not stick a laser fiber in the tumor the same way to kill it,” Marks said. “This is akin to a lumpectomy for breast cancer. Instead of removing the whole organ, target just the cancer inside it. What we are doing with prostate cancer now is like using a sledgehammer to kill a flea.”
Up until now, capturing an image of a prostate cancer has been difficult because prostate tissue and tumor tissue are so similar. Precise, noninvasive surgical treatment has proved difficult as a result.
The study indicates that MRI improves the ability of physicians to perform precise, laser-based treatment. The new fusion-imaging method improves it even further, providing real-time ultrasound that more clearly delineates the tumor. By combining laser ablation with this fusion-imaging technique, the potential of laser ablation grows enormously.
However, the researchers noted that comprehensive biopsy follow-up indicated that treatment margins larger than previously thought necessary may be required for complete ablation of the tumor.
“This focal therapy provides a middle ground for men to choose between radical prostatectomy and active surveillance, between doing nothing and losing the prostate,” Marks said. “This is a new and exciting concept for prostate cancer treatment.”
The laser treatment is not yet approved for use in prostate cancer by the US Food and Drug Administration.
“I think we were so successful in this effort because of the experience we gained doing the targeted biopsies,” Marks said. “That allowed us to go from biopsy to treatment.”
1. Natarajan S, Raman S, Priester AM, et al. Focal laser ablation of prostate cancer: phase I clinical trial. J Urol. 2016;196(1):68-75.