Guideline Update Supports Laser Therapy for Brain Tumors After SRS

The REMASTer trial found that laser interstitial thermal therapy was equivalent to open craniotomy regarding OS and PFS data in progressive metastatic brain tumors.

The College of Neurological Surgeons (CNS) has issued clinical guidelines supporting the use of laser interstitial thermal therapy (LITT) in adult patients with progressive metastatic brain tumors following stereotactic radiosurgery (SRS), according to a press release from Monteris Medical.1

Regarding overall survival (OS) and progression-free survival (PFS), the CNS guidelines claim that LITT is equivalent to open craniotomy in patients with metastatic tumors who experienced radiographic progression following SRS. LITT has also been recommended as an alternative to medical management for patients who experienced imaging progression due to radiation necrosis.

“This represents an important validation that minimally invasive LITT is a critical tool for practicing neurosurgeons facing the radiographic progression conundrum in the treatment of patients with brain metastases,” Adrian Laxton, MD, professor of neurological surgery and REMASTer principal investigator at Wake Forest University School of Medicine in Winston-Salem, NC, stated in the press release.1 “The REMASTer trial aims to characterize the optimal timing of early identification and intervention in this complex patient population.”

The new guidelines highlight the recent use of LITT in metastatic neuro-oncology diseases and are supported by Level 1 evidence from the randomized, controlled, post-market REMASTer trial (NCT05124912) that is evaluating LITT with the NeuroBlate® system as an early intervention therapy for radiographic progression in brain metastasis that was previously treated with radiosurgery.

The NeuroBlate system is a minimally invasive system that enables a robotic interface for the precise and safe delivery of laser energy and is intended for ablating intracranial soft tissue such as brain tumors, epileptic foci, and radiation necrosis.

In September 2022, the REMASTer trial announced the enrollment of its first patient.2

As of January 11, 2024, REMASTer had an estimated enrollment of 251 patients and is currently enrolling at 9 sites.

Eligible patients were 18 years or older and had radiographically proven, via gadolinium-enhanced MRI, parenchymal brain metastases from histologically confirmed non-central nervous system cancer with a bidimensionally-measurable intracranial lesion that is radiographically recurrent after prior SRS.3 Additional eligibility criteria include a Karnofsky performance status of 70 or greater, attainable frozen pathology diagnosis, at least 3 months removed from initial SRS, and target lesion amenable to undergo surgical biopsy and LITT treatment.

Exclusion criteria include more than 3 progressing lesions at the time of enrollment, concomitant newly diagnosed intracranial metastases, bevacizumab (Avastin) use within 4 weeks of study initiation, additional concurrent malignancies requiring active treatment, serious active infection or other serious underlying medical conditions, an inability to tolerate steroid therapy, and ineligibility to tolerate SRS therapy.

Primary trial end points include the efficacy of LITT with the NeuroBlate system measured by freedom from local progression in the progressive disease cohort and the efficacy of LITT vs standard medical management measured by time to steroid independence without care escalation in the radiation necrosis cohort. The secondary end points were to compare treatment approaches regarding OS in the progressive disease cohort and treatment approaches regarding freedom from local progression or neurologic death.

Those with recurrent tumors received either LITT followed by surveillance or LITT followed by hypofractionated radiation therapy; those with radiation necrosis either received LITT and best medical management with steroids or best medical management with steroids alone.

"The recognition by CNS that LITT is indispensable for neurosurgical programs, in addition to its endorsement for brain metastases patients, accentuates the substantial contributions of clinical evidence that Monteris and our physician partners have made over the years," stated Martin J. Emerson, president and chief executive officer of Monteris Medical in the press release.1 "The updates to CNS and NCCN guidelines, respectively, firmly establish LITT as a critical component in the care of brain tumor patients and emphasize our unwavering commitment to advancing LITT technology through our NeuroBlate® System."

The update to the CNS clinical guidelines further supports the use of LITT in brain cancers.

References

1. Monteris Medical announces College of Neurological Surgeons Guidelines issued on laser interstitial thermal therapy for the treatment of adults with metastatic brain tumors. News release. Monteris Medical. April 1, 2025. Accessed April 1, 2025. https://tinyurl.com/3sk9zucb
2. Monteris Medical announces first patient enrolled in REMASTer clinical study on NeuroBlate® system for metastatic brain tumor patients. News release. Monteris Medical. September 7, 2022. Accessed April 1, 2025. https://tinyurl.com/b5zmrfju
3. REMASTer: REcurrent brain metastases after SRS trial. ClinicalTrials.gov. Updated December 5, 2024. Accessed April 1, 2025. https://tinyurl.com/3sk9zucb