Summary & Overview
CPT 61736: Laser Interstitial Thermal Therapy for Single-Trajectory Brain Lesion
CPT code 61736 represents laser interstitial thermal therapy (LITT) for a simple brain lesion using a single trajectory. This minimally invasive neurosurgical procedure uses laser energy to ablate targeted brain tissue, often with MRI guidance to plan and monitor the thermal lesion. Nationally, LITT procedures are increasingly relevant as neurosurgical teams adopt image-guided thermal ablation for select tumor and lesion indications, with implications for site-of-service decisions, capital investment in MRI-capable suites, and payer coverage policies.
Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical and billing overview of the procedure, common modifiers and billing considerations, typical sites of service, and the types of documentation and coding contexts that commonly accompany 61736. The publication outlines common policy and reimbursement themes affecting adoption and utilization, summarizes benchmarking context where available, and highlights clinical scenarios and service-line impacts relevant to neurosurgery and hospital administrators.
This summary is written for a national audience and is intended to provide a clear, practical reference on the clinical service represented by CPT code 61736, its billing context, and what to expect in payer coverage and operational planning. Data not available in the input is noted where applicable in the full publication.
Billing Code Overview
CPT code 61736 describes laser interstitial thermal therapy (LITT) of a simple brain lesion requiring a single trajectory. The procedure involves using a laser to thermally ablate or damage targeted brain lesion tissue. The provider may use magnetic resonance imaging (MRI) guidance to plan, monitor, and confirm the thermal ablation.
Service type: Minimally invasive neurosurgical ablation procedure
Typical site of service: Hospital inpatient or outpatient surgical setting, ambulatory surgery center, or specialty neurosurgical suite with MRI guidance capability
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult with a solitary, well-circumscribed intracranial lesion such as a metastatic tumor, radiation necrosis, or a small primary brain tumor located deep in the parenchyma where open craniotomy poses higher risk. The patient presents with focal neurologic symptoms, progressive headaches, or radiographic progression on MRI. Pre-procedure workflow includes neurologic and neurosurgical evaluation, MRI with contrast for lesion characterization and trajectory planning, multidisciplinary review with neuro-oncology or radiation oncology as needed, informed consent discussing risks and benefits of 61736 (laser interstitial thermal therapy with a single trajectory), and anesthesia evaluation. On the day of service the patient undergoes stereotactic frame-based or frameless registration in the OR or MRI suite, percutaneous stereotactic placement of the laser fiber along a single planned trajectory, real-time MRI thermometry when available to monitor ablation, controlled application of thermal energy until adequate lesion coverage is achieved, and removal of the laser catheter. Post-procedure care includes short observation in a post-anesthesia care unit, early postoperative MRI to assess ablation zone when indicated, neurologic checks, pain management, and discharge planning with follow-up imaging and neuro-oncology/neurosurgery clinic visits.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
11 | Normal (primary) procedure |