Answer:
Add-on-code is 92974.
Step-by-step explanation:
Transcatheter placement of radiation delivery device for subsequent coronary intravascular brachytherapy. This code is reported in the reference given below and also on the Current Procedural Terminology database.
Reference: Buck, Carol J. Workbook for Step-by-Step Medical Coding, 2014 Edition-E-Book. Elsevier Health Sciences, 2014.