Currentpriority healthPolicy N/A

Laser Interstitial Thermal Therapy (LITT)

Defines coverage criteria, limitations, and clinical indications for MRI-guided Laser Interstitial Thermal Therapy (LITT/MRgLITT) for Priority Health members, including indications for refractory epilepsy and select brain tumors/radiation necrosis.

Policy Summary

Payerpriority health

PolicyLaser Interstitial Thermal Therapy (LITT)

Policy CodePolicy N/A

Change TypeNo material change

Effective Date03/01/2026

Next Review DateN/A

Key ActionSubmit prior authorization with clinical documentation demonstrating medical necessity when prior authorization is required.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

2primary covered indications

2CPT codes listed

2Not covered Category III codes

03/01/2026effective date

Coverage Criteria and Medical Necessity

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Refractory epilepsy indication

Medication failure: Documentation of drug resistant or medication-refractory epilepsy defined as failure to respond to, or intolerance of, at least 2 antiepileptic drug regimens for disabling and localization-related epilepsy>=2 failed AED regimens
Anatomic suitability: Well-defined epileptogenic foci or critical pathways of seizure propagation accessible by MR-gLITT
Multidisciplinary agreement: Documentation that LITT is the best treatment option as agreed upon by a multidisciplinary team (eg, neurologist, neurosurgeon, neurophysiologist, neuroradiologist, psychiatrist)

Primary/recurrent brain tumors and relapsed brain metastases indication

Surgical risk or inaccessibility: Member is a poor surgical candidate for craniotomy and resection; open surgery presents prohibitive surgical risk; or the tumor is located at a surgically inaccessible site
policy items a-c
Multidisciplinary agreement: Documentation that LITT has been agreed upon by a multidisciplinary team (eg, neurosurgery, oncology) after considering all relevant possible treatment approaches

Device examples: Policy cites NeuroBlate and Visualase Thermal Therapy System as examples of MRgLITT devices

informational

LITT (also known as MR-gLITT) is covered only for the specific indications and criteria listed in this policy. LITT is considered experimental and/or investigational for all other conditions not explicitly included under the medical necessity section because there is insufficient evidence demonstrating effectiveness on health outcomes for those uses.

Procedure and Billing Codes

Covered CPT CodesCPTCovered

61736	Laser interstitial thermal therapy (LITT) of lesion, intracranial, including burr hole(s), with magnetic resonance imaging guidance, when performed; single trajectory for 1 simple lesion
61737	Laser interstitial thermal therapy (LITT) of lesion, intracranial, including burr hole(s), with magnetic resonance imaging guidance, when performed; multiple trajectories for multiple or complex lesion(s)

Not Covered / ExamplesCPTNot Covered

0970T	Ablation, benign breast tumor (eg, fibroadenoma), percutaneous, laser, including imaging guidance when performed, each tumor
0971T	Ablation, malignant breast tumor(s), percutaneous, laser, including imaging guidance when performed, unilateral

Not CoveredCPTNot Covered

0970T	Ablation, benign breast tumor (eg, fibroadenoma), percutaneous, laser, including imaging guidance when performed, each tumor
0971T	Ablation, malignant breast tumor(s), percutaneous, laser, including imaging guidance when performed, unilateral

Provider Requirements, Prior Authorization, and Documentation

Prior Authorization

Prior Authorization May Be Required

Prior authorization may be required for this procedure. Providers should check the Priority Health Provider Manual and member benefits to determine if prior plan approval is needed before scheduling LITT.

Check member-specific benefits and plan coverage prior to scheduling.
When required, submit a prior authorization request to Priority Health.

Prior Authorization

Prior Authorization Requirement

When prior authorization is required, the provider must submit documentation demonstrating medical necessity and obtain plan approval before the service is performed.

Submit a complete prior authorization request showing the clinical rationale for LITT.
Obtain written plan approval before proceeding when prior authorization is a requirement.

Documentation Required

Required Clinical Documentation

Providers must submit clinical documentation demonstrating the specific criteria for medical necessity. Documentation should include evidence of drug-resistant epilepsy or surgical unsuitability for tumor resection, and confirmation of a well-defined epileptogenic focus or tumor location.

For refractory epilepsy: documentation of drug‑resistant epilepsy (failure of ≥2 antiepileptic drug regimens), well‑defined epileptogenic focus accessible by MR‑gLITT, and multidisciplinary team agreement.
For primary/recurrent brain tumors or relapsed brain metastases: documentation that the member is a poor surgical candidate, open surgery is prohibitive or lesion is surgically inaccessible, and multidisciplinary team agreement.

Denial Risk

Prior Authorization / Investigational Denial Risk

Requests that lack required prior plan approval when prior authorization is mandated, or requests for indications considered experimental/investigational, may be denied. Coverage determinations for experimental, investigational, or unproven treatments are made by a Priority Health medical director or clinical pharmacist.

Requests without prior authorization when required may be denied.
Treatments determined to be experimental/investigational (see exclusions such as radiation necrosis) may be denied unless exception criteria are met.

Note

Provider Action — Not Specified

Provider action: Not specified in source — if additional provider actions are required beyond prior authorization and documentation, follow instructions in the Priority Health Provider Manual or contact medical management for guidance.

When in doubt, contact Priority Health medical management for individual case review or instructions.
Individual case review may allow coverage for investigational yet promising treatments but requires prior plan approval.

Background and Rationale

Laser Interstitial Thermal Therapy (LITT), often referred to as MR-guided LITT (MR-gLITT), delivers thermal energy via an implanted laser fiber under MRI guidance to produce localized tissue ablation. It is used as a less-invasive alternative to open craniotomy in select patients, including those with drug‑resistant focal epilepsy with well‑defined epileptogenic targets and in selected cases of primary or recurrent brain tumors and relapsed brain metastases when open resection is high risk or the lesion is surgically inaccessible. The policy cites device examples such as NeuroBlate and Visualase as representative MRgLITT systems.

Definitions and Professional Guidance

LITT / MRgLITT — definition of Laser Interstitial Thermal Therapy

TermLaser Interstitial Thermal Therapy (LITT) — also referred to as Magnetic Resonance-Guided LITT (MRgLITT)

DefinitionSelective ablation of a lesion or tissue using thermal energy from a laser optical fiber with MRI guidance; light energy is converted to thermal energy causing protein denaturation, cellular necrosis, and tissue coagulation.

Common devices citedNeuroBlate and Visualase Thermal Therapy System (examples referenced in policy)

Clinical intentLess invasive option for patients who would not tolerate larger surgical resection or who have deep/inaccessible lesions or lesions resistant to alternative therapies.

Drug‑resistant epilepsy definition — failure of >=2 antiepileptic drug regimens

DefinitionDrug‑resistant (medication‑refractory) epilepsy — failure to respond to, or intolerance of, at least 2 antiepileptic drug regimens for disabling and localization‑related epilepsy.

Documentation requirementClinical records must document the >=2 failed AED regimens and that epilepsy is disabling and localization‑related.

Context of useRequired criterion for LITT coverage under the refractory epilepsy indication.

Position statements — professional society guidance referenced (AANS/CNS, ASSFN)

AANS/CNS positionAmerican Association of Neurological Surgeons and Congress of Neurological Surgeons: Position Statement on MR‑Guided LITT for Brain Tumors and Radiation Necrosis (Barnett et al., 2021).

ASSFN / relatedPolicy references additional professional guidance and NCCN materials in the references section supporting considerations for LITT in CNS cancers.

Role in policyPosition statements are cited to contextualize indications and evidence for MR‑guided LITT for brain tumors and radiation necrosis.

Systematic reviews — multiple systematic reviews and meta-analyses cited

Systematic reviews citedMultiple systematic reviews and meta‑analyses are referenced, including reviews on LITT for radiation necrosis and for hypothalamic hamartomas and temporal lobe epilepsy (eg, Ahluwalia et al. 2018; Ahmed et al. 2024; Brenner et al. 2024).

Radiation necrosis evidenceQualitative systematic review: Cuschieri et al., 2023 — LITT for biopsy‑proven radiation necrosis.

Epilepsy and functional outcomesSystematic reviews/meta‑analyses on MRI‑guided LITT for epilepsy and functional outcomes (eg, Brenner et al., 2024; Ahmed et al., 2024).

Metastatic brain tumors and outcomesProspective multicenter and systematic literature reviews addressing LITT after stereotactic radiosurgery for metastatic brain tumors and radiation necrosis (eg, Ahluwalia et al., 2018; Gecici et al., 2024).