Summary & Overview
CPT 77371: Stereotactic Radiosurgery Technical Component, Cobalt-60
CPT code 77371 represents the technical component of stereotactic radiosurgery (SRS) delivered with a multi-source Cobalt 60 system to target small intracranial lesions using a three-dimensional coordinate system. This code is important nationally because it captures facility and equipment-related resources for a high-acuity, technology-dependent radiation therapy service that influences hospital outpatient and freestanding radiation oncology billing and capacity planning.
Payers covered in this review include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context for SRS delivered with Cobalt 60, the places of service where the technical component is typically billed, common modifiers encountered in claims, and the role of 77371 in differentiating technical versus professional billing for radiosurgery episodes.
The publication outlines benchmarks and reimbursement context, highlights billing and coding considerations specific to the technical component, and summarizes policy and payer coverage trends affecting access to stereotactic radiosurgery. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 77371 describes the technical component of stereotactic radiosurgery using a multi–source Cobalt 60 system. The procedure employs a three-dimensional coordinate system to locate small intracranial targets or lesions and delivers high-energy gamma radiation from externally generated sources to destroy those targets.
Service Type: Stereotactic radiosurgery, technical component
Typical Site of Service: Hospital outpatient department or specialized radiation oncology center
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient presents with a solitary 1.2 cm metastatic lesion in the deep parietal lobe identified on MRI and confirmed by neurosurgery and radiation oncology as appropriate for stereotactic radiosurgery (SRS). The treatment team elects single-fraction SRS using a multi-source Cobalt-60 gamma unit to deliver a high-dose, highly conformal plan to the intracranial target. The clinical workflow includes pre-procedure evaluation and informed consent, high-resolution MRI and CT simulation with stereotactic localization, target delineation by radiation oncology and neurosurgery, dosimetric planning by the medical physicist, treatment delivery under the technical services of the radiation therapy department (frame or frameless immobilization), post-treatment observation, and scheduled radiographic follow-up.
Typical site of service is an outpatient radiation oncology center or hospital-based radiation therapy department equipped with a multi-source Cobalt-60 stereotactic radiosurgery system. The patient is usually ambulatory, may require brief sedation or anesthesia for frame placement, and is discharged the same day with follow-up arranged.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
TC | Technical component | When billing only the technical component of SRS (equipment, physics, and technical staff) — typical use with 77371 when professional component billed separately |