Oncology & Hematology Coding Alert

Question: What is the real date of service for basic dosimetry calculations, 77300? Is it the day the patient is being simulated for radiation treatment or is it the day the dosimetrist is calculating?

Indiana Subscriber

Answer: The dosimetrist does not require the presence of the patient to complete his professional services. Therefore, the date of service should be when the calculations are done. For example, if the patient was seen on Monday, and the calculation was performed the following day, 77300 (basic radiation dosimetry calculation, central axis depth dose, TDF, NSD, gap calculation, off axis factor, tissue inhomogeneity factors, as required during course of treatment, only when prescribed by the treating physician) should be billed on Tuesday.

Calculation can be done on the date of simulation, but does not need to be. For example would be the patient is simulated on Monday. The dosimetrist does not complete the calculations until Wednesday. Wednesdays date should be used as the date for billing 77300, while the simulation, 77280-77295, would be billed on Monday.