Laser surgery is old hat. Doctors have been burning through blocked arteries, hemorrhoids, ulcers, liver tumors, damaged corneas, gastric cancers and any number of other things you'd prefer not to have inside your body, for years. So why haven't we set our laser sights on prostate cancer?
As it turns out, there's a fascinating reason: the prostate cancer tumor looks too much like the prostate itself, the tissues are so similar. Precise, non-invasive surgical treatment has proved difficult as a result.
But now researchers from UCLA have developed a technique that puts prostate tumors under the beam. The technique uses magnetic resonance imaging, or MRI, to guide the insertion of a laser fiber into cancerous tumors. When heated, the laser destroys the cancerous tissue.
“If the laser technique, known as MRI-guided focal laser ablation, proves effective in further studies -- especially using the new MRI-ultrasound fusion machine -- it could improve treatment options and outcomes for men treated for such cancers,” said study senior author Dr. Leonard Marks, a professor of urology and director of the UCLA Active Surveillance Program. Historically, prostate cancer has been treated with surgery and radiation, which can result in serious side effects such as erectile dysfunction and urinary incontinence.
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.
"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."
Previous research at UCLA has demonstrated the value of using the same fusion imaging technique to perform biopsies to diagnose prostate cancers in men with rising PSA who had multiple negative conventional biopsies. Such biopsies are usually "blind," meaning physicians take a tissue sample based on what they believe is the location of a possible tumor.
The new Journal of Urology study provides proof of principle that laser ablation can be done safely and effectively with MRI. In this case, eight men underwent ablation while in an MRI machine. Although none had serious side effects, longer-term follow-up is needed, as is a continued assessment of appropriate treatment margins to ensure cure, the researchers said.
The laser treatment is not yet approved for use in prostate cancer by the U.S. Food and Drug Administration.