IR Quarterly

Coding Q&A

Q: What are the appropriate codes to use when microwave ablation is the energy source used for liver, lung or renal lesions?

Answer: The existing Current Procedural Terminology (CPT) codes for tumor ablation are defined for radiofrequency ablation. This definition has led to some confusion, resulting in the use of unlisted procedure codes for microwave ablation. SIR does not recommend the use of unlisted procedure codes for microwave ablation of kidney, lung or liver tumors.

Microwave is part of the radiofrequency spectrum and simply uses a different part of the radiofrequency spectrum to generate heat energy to destroy abnormal soft tissue. Microwave ablation equipment is substantially comparable to operate in practice, which is also reflected in the U.S. Food and Drug Administration (FDA) approval of microwave devices under the 510(k) clearance process as equivalent to radiofrequency.

As such, SIR recommends that CPT codes 47382, 32998 and 50592 be used for both microwave and radiofrequency ablation in their respective anatomic locations, in conjunction with the appropriate imaging guidance code:

• 47382: Ablation, one or more liver tumor(s), percutaneous, radiofrequency; with appropriate image guidance code: 77013 (CT), 76940 (US), 77022 (MRI)
• 32998: Ablation therapy for reduction or eradication of one or more pulmonary tumor(s) including pleura or chest wall when involved by tumor extension, percutaneous, radiofrequency, unilateral; with appropriate image guidance code: 77013 (CT), 76940 (US), 77022 (MRI)
• 50592: Ablation, one or more renal tumor(s), percutaneous, unilateral, radiofrequency; with appropriate image guidance code: 77013 (CT), 76940 (US), 77022 (MRI)

Q: When is it appropriate to code for a nephrostogram during a tube change?

Answer: There is much confusion about the use of CPT codes 50398 and 50394:

• 50398: Change of nephrostomy or  pyelostomy tube
• 50394: Injection procedure for pyelography— as nephrostogram, pyelostogram, antegrade pyeloureterograms—through nephrostomy or pyelostomy tube or indwelling ureteral catheter

The position of SIR is that contrast injection used for basic anatomy during nephrostomy tube exchange is part of the procedure, is therefore included in CPT code 50398, and should NOT also be coded as a diagnostic nephrostogram.

Coding for both under this circumstance is an area of potential misuse of the codes. There are occasions when a diagnostic study is performed at the same time as a tube change. Under that circumstance, it is appropriate to include CPT code 50394 with the -59 modifier. The use of modifier -59 with CPT code 50394 indicates that a true diagnostic study was performed. CMS does allow the use of National Correct Coding Initiative (NCCI)-associated modifiers for clinical scenarios where the patient having a tube change also presents with new symptoms related to the tube.

For example:

• A patient presents with pain and leakage in the area surrounding his nephrostomy tube.
• Contrast is injected, a diagnostic nephrostogram is performed, and it is determined, on the basis of the diagnostic study, that the tube must be changed.
• Codes 50398 and 50394-59 are reported. 

Disclaimer: SIR assumes no liability, legal, financial or otherwise for physicians or other entities who utilize this information in a manner inconsistent with the coverage and payment policies of any payers or Medicare contractors to which the physician or other entity has submitted claims for the reimbursement of services performed by the physician. CPT codes and their descriptors are copyright 2012 by the American Medical Association.