According to the CPT assistant if placing an expandable catheter device at the time of a partial mastectomy, code 19499, Unlisted procedure, breast, should be reported in addition to the appropriate mastectomy procedure code.
Code 19296, Placement of radiotherapy afterloading balloon catheter into the breast for interstitial radioelemnt application following a partial mastectomy, includes imaging guidance, on date seprate from partial mastectomy, should be reported for the exchange of the cavity evaluation device with the insertion of a radiotherapy afterloading balloon catheter that is performed on a separate date from that of the breast excision. I hope this helps.