Did you know that Focal Laser Ablation (FLA), which we use in our Center for precision destruction of prostate lesions, has a range of applications in other organs and tissues? For example, the optic fiber that transmits the laser light can be safely directed into tumors in lung, liver, bone, etc.

In fact, decades before MRI-guided FLA was FDA cleared for use in the prostate, researchers recognized its potential as an alternative to more invasive neurosurgical procedures. After years of animal experiments, the first report of treating a cancerous brain tumor with laser occurred in 1966.^[i] It was an open brain cancer neurosurgery using a different type of laser light; the treatment was incomplete, but it was a historic moment. However, it would be another two decades until a minimally invasive delivery system was developed that could be used under MRI guidance for accurate targeting of brain tissue without collateral damage.

MRI-guided LITT

The technical term for FLA using an optic fiber is Laser Interstitial Thermal Therapy (LITT) defined as the selective ablation of a lesion or a tissue using heat emitted from a laser device.^[ii] Thanks to advances in imaging, today’s LITT is guided by MRI (MRgLITT or MRgFLA), which enables pretreatment mapping of the target area, treatment planning and precision guidance, monitoring ablation during treatment using thermal software, and post-treatment confirmation of the ablation zone. These are the same principles and processes we use when treating both prostate cancer and benign prostatic hyperplasia (BPH)

Today, MRgFLA is used for a variety of brain disorders, especially tumors. Its advantages include:

• It is minimally invasive, as only a tiny hole in the skull is needed for the laser applicator
• It can be focused on very small areas, e.g., stopping seizures that come from a single region in the brain
• Its recovery is usually shorter and less painful than open neurosurgery
• It allows neurosurgeons to gain access to some tumors that are close to sensitive structures
• It allows for deeper penetration into the brain where an open brain surgery would be riskier.

MRgFLA is, of course, not without risk. All neurosurgical procedures involve some risk of side effects or disappointing results. Nonetheless, for focal treatment in the brain, MRgFLA has proven its worth time and again, as the following news story shows.

MRgFLA for childhood epilepsy

Small previous studies have demonstrated that in children whose epilepsy does not respond to medication, MRgFLA may be effective (sadly, many kids on various drugs for their epilepsy have a less than 10% chance of seizure freedom^[iii] The exciting news is a much larger study (nearly 150 children with focal epilepsy), thanks to a data registry that draws on cases from 7 U.S. centers and 2 Canadian centers.

The results of the study were presented at the online conference of the American Epilepsy Society (AES) 74th Annual Meeting 2020. The purpose of the research analysis was to better understand outcomes and side effects of MRgFLA for pediatric epilepsy. It’s worth noting that the brain areas involved varied among the children, all of whom had been on an average of nearly 3 drugs up to the time of their ablation.

Study results

According to the news report, “Among 137 patients for whom 1-year seizure outcomes were available, seizure freedom was reported for 74 patients (54%).”^[iv] This compares with a seizure-free rate of 65% among children who have open neurosurgery. One member of the study team noted this difference and pointed out that MRgFLA is more cost-effective with an average of 3.3 days in the hospital, compared with a week, and the minimal invasiveness makes for less risk and a more favorable recovery experience. In addition, MRgFLA can access regions deep in the brain without collateral damage, and it can be repeated if necessary.

Regarding side effects, 15% of the patients had some degree of treatable infection or bleeding. Only 8% had resulting neurological deficits but these tended to resolve on their own. However, two cases (1%) experienced permanent weakness of arms or legs, but compare this against the 5% rate following open neurosurgery.

More faith in Focal Laser Ablation

This study was well-received since this minimally invasive focal approach to durable seizure relief for many children will greatly improve their quality of life. Similarly, MRI-guided FLA for prostate tumors has grown beyond its early promise to a recognized standard of care for men whose focal prostate cancer qualifies for our treatment. The fact that this treatment modality can be done with such delicacy in the brain for a condition as compromising as children’s epilepsy further earns the trust and confidence that we, at Sperling Prostate Center, place in FLA for prostate cancer.

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.

References

[i] Rosomoff HL, Carroll F. Reaction of neoplasm and brain to laser. Arch Neurol. 1966:14(2):143-8.
[ii] Salem U, Kumar VA, Madewell JE et al. Neurosurgical applications of MRI guided laser interstitial thermal therapy (LITT). Cancer Imaging 19, 65 (2019).
[iii] Anderson, Pauline. “New Laser Therapy Promising in Kids with Resistant Epilepsy.” Medscape Medical News, Dec. 9, 2020. https://www.medscape.com/viewarticle/942346
[iv] Ibid.