Over the years, stereotactic radiosurgery (SRS) coding has changed significantly. Prior to 2009, CPT 61793 was used with the appropriate modifiers and associated 77xxx series of codes. Code 61793 was deleted on Dec. 31, 2008. In 2009, new neurosurgical codes were introduced for SRS. These new codes reflected the growth in SRS to treat spinal lesions and also the use of SRS to treat more than one lesion at a time, principally in brain metastasis patients.

For intracranial radiosurgery, the following codes are used:

• 61793- Stereotactic radiosurgery (deleted 12/31/2008)
• 61796- Simple lesion (1 unit)
• 61797- Additional simple lesions up to a maximum 4 units
• 61798- Complex lesion (1 unit)
• 61799- Additional complex lesions up to a maximum 4 units
• 61800- Stereotactic frame application
• 20665- Stereotactic frame removal

A simple lesion is defined as a target with a dimension of less than 3.5 cm and more than 5 mm away from the optic apparatus or brainstem. A complex lesion is one that has a dimension of 3.5 cm or greater, or is adjacent (5 mm or less) to critical structures such as the optic apparatus (nerve, chiasm or tract) or brainstem. In addition, intracranial pathology such as schwannomas, arteriovenous malformations, pituitary tumors, glomus tumors, pineal region tumors and cavernous sinus/parasellar/petroclival tumors are considered complex. If any one lesion is complex, the primary code used will be 61798, with additional lesions being billed as 61797 or 61799, depending on their type.

For spinal radiosurgery, the following codes are utilized:

• 63620 Stereotactic radiosurgery (particle beam, gamma ray or linear accelerator); 1 spinal lesion
• 63621 Stereotactic radiosurgery (particle beam, gamma ray or linear accelerator); each additional spinal lesion (List separately in addition to code for primary procedure.)

For most insurers, stereotactic radiosurgery (SRS) is considered medically necessary when used in the treatment of simple cranial lesions that are less than or equal to 3.5 cm in maximum dimension, or complex cranial lesions that are greater than 3.5 cm in maximum dimension, for patients with the following conditions:

• Intracranial arteriovenous malformations (AVM)
• Acoustic neuromas
• Pituitary adenomas (Cushing’s disease or acromegaly)
• Non-resectable, residual, or recurrent meningiomas
• Craniopharyngiomas
• Pineal gland neoplasms
• Solitary or multiple brain metastases originating from other primary sites (initial treatment or treatment of recurrence for patients having good performance status and no active systemic disease)
• High-grade gliomas (initial treatment or treatment of recurrence)
• Trigeminal neuralgia refractory to medical management
• Jugular foramen or vestibular schwannomas
• Uveal melanoma

Stereotactic radiosurgery also is considered medically necessary when used in the treatment of:

• Primary or recurrent tumors within the spine, or metastases to the spine from other primary sites, that are both:
  • Not amenable to surgery (for example, due to prior surgery, tumor location or patient ability to withstand surgery); and
  • Not amenable to conventional radiation therapy (for example, stereotactic precision is required to avoid unacceptable radiation to unaffected tissues)

Due to the team nature of SRS, there has been confusion regarding the components needed for the neurosurgical service to be coded as SRS. Many payors have advocated that the SRS codes should only be used by the neurosurgeon, as one member of the team, when the neurosurgeon is (a) present; (b) medically necessary; and (c) fully participating, during the complete course of the procedure. However, this is not universally accepted, as the radiation oncologist is not held to the same standard, because he or she is required to fully participate only “in the coded procedure.” Clearly, neurosurgeons should be involved in more than just the frame application, particularly since many SRS cases do not use a frame, and the neurosurgeon must be fully participating in those aspects of SRS that are related to the neurosurgeon’s role in taking care of the patient. This includes:

• Pre-operative assessment of the patient
• Treatment planning
• Oversight of the procedure itself
• Health needs of the patient related to the SRS procedure during the 90-day global period

The CPT coding structure for SRS accurately accounts for the services provided by the neurosurgeon as a member of the SRS team. For multisession radiosurgery, neurosurgeons should be physically present for at least one session in order to bill for the procedure. They may not bill more than once for such a procedure, even if present for more than one session.

For further information on correct coding of Stereotactic Radiosurgery, please refer to the “AANS/CNS Statement on Coding and Reimbursement for Stereotactic Radiosurgery,” along with the article from the January 2007 Journal of Neurosurgery entitled “Stereotactic Radiosurgery—An Organized Neurosurgery-Sanctioned Definition.” These documents will provide further details about the history of SRS, the respective roles of the neurosurgeon and radiation oncologist, the modern definition of SRS and other information about this surgical procedure.

Joseph S. Cheng, MD, FAANS, is director of the Neurosurgery Spine Program in the Department of Neurological Surgery at Vanderbilt University Medical Center in Nashville, Tenn. Jason Sheehan, MD, PhD, FAANS, is the alumni professor of neurological surgery at the University of Virginia in Charlottesville, Va. The authors reported no conflicts for disclosure.

References

1. AANS/CNS Statement on Coding and Reimbursement for Stereotactic Radiosurgery, Nov. 18, 2008.
2. Barnett GH, Linskey ME, Adler, JR, et. Al. Stereotactic radiosurgery—an organized neurosurgery-sanctioned definition. J Neurosurg 106:1–5, 2007.