Neurosurgery Coding Alert

Question: Our surgeon is planning to do cyberknife procedure 61796 (Stereotactic radiosurgery [particle beam, gamma ray, or linear accelerator]; 1 simple cranial lesion) for 3 consecutive days one different lesion a day, left occipital, left parietal and left frontal. Is modifier 79 (Unrelated procedure or service by the same physician during the postoperative period...) appropriate in this situation?

Colorado Subscriber

Answer: The medical necessity of performing radiosurgery treatment of three different lesions on three separate consecutive days is questionable. Since multiple simple intracranial lesions likely represent metastatic disease (and therefore the same diagnosis code), the 79 modifier would not be applicable. The radiosurgery code includes fractionated treatment of the same lesion over a limited number of sessions. Without additional rationale to describe the reason for the scenario described, this would best be reported with 61796 and 2 units of 61797 for the additional two lesions and should be performed on the same day.