Radiology Coding Alert

Tip: Look for the structure targeted and the intent of the procedure.

When your radiologist performs stereotactic procedures for the skull or brain, you will encounter several anatomical terms that seem like jargon, which can leave you perplexed. Here is how you can hit the right code without any confusion.

Ascertain What Your Physician Does

When you read that your physician attempted a stereotactic procedure, you can determine the right code only when you confirm the precise intent of the procedure.

If your physician performs a stereotactic biopsy under radiological guidance, you report code 61751 (Stereotactic biopsy, aspiration, or excision, including burr hole[s], for intracranial lesion; with computed tomography and/or magnetic resonance guidance).

Example: You may read that your physician aspirated a colloid cyst in the third ventricle with MRI guidance. In this case, you report code 61751.

Similarly, you report code 61770 (Stereotactic localization, including burr hole[s], with insertion of catheter[s] or probe[s] for placement of radiation source) when your physician attempts stereotactic localization and placing a probe or catheter for the delivery of the radioactive seeds. Your radiologist may work with a radiation physician and neurophysician for implanting the seeds.

Confirm Site of Stereotactic Lesions

If your physician studied the radiological impressions of the thalamic lesions using CT scan, you should be able to locate the same in the operative note.

Example: Your physician may typically describe the CT appearance of a thalamic lesion having as a discrete central core of increased attenuation surrounded by an area of decreased attenuation.

For stereotactic lesions in the globus pallidus or thalamus, you report code 61720 (Creation of lesion by stereotactic method, including burr hole[s] and localizing and recording techniques, single or multiple stages; globus pallidus or thalamus).

Get to know the anatomy: Globus pallidus is a structure in the brain that regulates voluntary movements in the body. Thalamus is a symmetrical midline structure in the brain. It acts as a switchboard or relay station for various sensory and motor signals to the higher centers in the brain. The thalamus also regulates sleep and alertness. “The thalamus is a complicated subcortical structure that serves as a relay station for a variety of motor and sensory inputs. Consequently, it can be a source of movement disorders or pain syndromes,” says Gregory Przybylski, MD, director of neurosurgery, New Jersey Neuroscience Institute, JFK Medical Center, Edison.

Reason for lesions: Your radiologist will work with the neurophysician to create a lesion in the globus pallidus to control abnormal involuntary muscle tremors. If you are able to locate the term ‘pallidotomy’ in the operative note, you can be assured that your physician created a lesion in the globus pallidus. “The frequency of destructive procedures for movement disorders has declined with the increasing understanding and effectiveness of deep brain stimulation,” says Przybylski.

When you are able to locate the term ‘thalamotomy’ in the procedure note, you confirm that your physician made a lesion in the thalamus. This is usually done to treat a pain syndrome.

When you learn that your physician worked on other brain structures that are anatomically located below the cerebral cortex but not the globus pallidus or thalamus, you report code 61735 (Creation of lesion by stereotactic method, including burr hole[s] and localizing and recording techniques, single or multiple stages; subcortical structure[s] other than globus pallidus or thalamus). You report 61735 for stereotactic lesions in structures like the hippocampus, amygdala, corpus callosum, cerebellum, and basal ganglia.

Note: Codes 61720 and 61735 are inclusive of the localization and recording techniques. “In addition, as these are considered stereotactic procedures, the placement of a frame, i.e. CPT® 20660 (Application of cranial tongs, caliper, or stereotactic frame, including removal [separate procedure]), if performed for frame-based procedures, as well as the use of neurological navigation, i.e. CPT® 61781 (Stereotactic computer-assisted [navigational] procedure; cranial, intradural [List separately in addition to code for primary procedure]) are both considered bundled services,” says Przybylski.

Watch for These Anatomy Specifics with Radiofrequency Neurolysis

Your physician may be using the radiofrequency as a neurolytic agent to manage trigeminal neuralgia. The only difference you can spot in the descriptors of codes 61790 (Creation of lesion by stereotactic method, percutaneous, by neurolytic agent [e.g., alcohol, thermal, electrical, radiofrequency]; gasserian ganglion) and 61791 (Creation of lesion by stereotactic method, percutaneous, by neurolytic agent [e.g., alcohol, thermal, electrical, radiofrequency]; trigeminal medullary tract) is that 61790 refers to the Gasserian ganglion and 61791 refers to the medullary tract. “The former procedure is more commonly done as a method to manage trigeminal neuralgia,” says Przybylski.

Remember: Gasserian ganglion is also called the trigeminal or semilunar ganglion. Your radiologist will work with a neurophysician to approach the trigeminal nucleus through the foramen ovale. So you can look for this approach in the operative note and confirm that 61790 is the right code to report. For brainstem lesions, you report 61791.

Note: You’ll typically report 350.1 (Trigeminal neuralgia) as a diagnosis for either 61790 or 61791.

Radiosurgery: Count the Lesions

You report code 61796 (Stereotactic radiosurgery [particle beam, gamma ray, or linear accelerator]; 1 simple cranial lesion) or 61798 (Stereotactic radiosurgery [particle beam, gamma ray, or linear accelerator]; 1 complex cranial lesion) depending upon the simple or complex lesion your physician created. “Given the differences in physician work between planning and treating a simple, smaller and/or uniform lesion compared with an irregular, larger, and more dangerously-located lesion, the former single radiosurgery code descriptor was revised to account for the differences in work and complexity a number of years ago,” says Przybylski.

Simple vs complex: Complex lesions include those that are adjacent (5 mm or less) to the optic nerve/optic chasm/optic tract or within the brain stem. Certain types of lesions are inherently considered complex. These include schwannomas, arterio-venous malformations, pituitary tumors, glomus tumors, pineal region tumors, and cavernous sinus/parasellar/petroclival tumors. Simple cranial lesions are less than 3.5 cm in maximum dimension that do not meet the CPT® definition of a complex lesion.

If the physician treats multiple lesions, you’ll add either +61797 (Stereotactic radiosurgery [particle beam, gamma ray, or linear accelerator]; each additional cranial lesion, simple [List separately in addition to code for primary procedure]) or +61799 (Stereotactic radiosurgery [particle beam, gamma ray, or linear accelerator]; each additional cranial lesion, complex [List separately in addition to code for primary procedure]) to your claim, based on whether the lesions are simple or complex. You can include either of these add-on codes for a maximum of five lesions treated during the session.

Don’t Forget the Head Frame

Linear accelerator based radiation is frameless. Many other treatment systems, however, are frame-based - which means you’ll add another code to your claim. If your physician uses a frame-based system, be sure to include +61800 (Application of stereotactic head frame for stereotactic radiosurgery [List separately in addition to code for primary procedure]) on your claim, says Marianne Schipper, CPC, a spine, brain, and endovascular coding specialist at Barrow Neurosurgical Associates in Phoenix, Ariz. Sometimes the neurophysician applies the frame but doesn’t participate in the rest of the radiosurgery procedure, says Deborah Messinger, CPC, a coding specialist with Massachusetts General Physicians Organization in Charlestown. In that case, your neurophysician’s practice can report 20660 (Application of cranial tongs, caliper, or stereotactic frame, including removal [separate procedure]) instead of +61800.