Coding Question 1:

A member has a question regarding DVH billing. He asks when a DVH is ordered by a physician and performed, not as part of a 3-D planning process, should it be coded as a 77305 (simple isodose plan), 77300 (basic dosimetry calculation) or another code? He has seen recommendations for both 77305 and 77300 charges.

CUAC Response 1:

There is no code that precisely describes the work of generating a dose-volume histograms (DVH) independent of the 3-D planning. If a DVH is requested without performing 3-D planning, then the ASTRO Code Utilization and Application Committee (CUAC) believes that CPT® code 77300 would be the most appropriate choice. The American Medical Association Current Procedural Terminology describes CPT code 77300 as; Basic radiation dosimetry calculation, central axis depth dose calculation, TDF, NSD, gap calculation, off axis factor, tissue inhomogeneity factors, calculation of non-ionizing radiation surface and depth dose, as required during course of treatment, only when prescribed by the treating physician. If the DVH is a “manually generated” entity, meaning that it is not a computer-generated curve from normal 3-D volume dose calculations, it may be appropriate to charge a CPT code 77370; Special medical radiation physics consultation, for this work. It must be specifically ordered by the physician and a report to the physician should be generated by the medical physicist for the work that is rendered. A limited computer plan, CPT code 77305; Teletherapy, isodose plan (whether hand or computer calculated); simple (one or two parallel opposed unmodified ports directed to a single area of interest), specifically describes work that is not performed as part of DVH generation and should not be reported in this setting.

Coding Question 2:

A member would like more clarification on the statement below from page 46 of the ASTRO/ACR Guide to Radiation Oncology Coding 2005: "As most patients will not require special dosimetry measurements..." Could you qualify the "most" statement?

Context taken from the Guide, page 46 Special dosimetry (CPT code 77331) is used to report the measurement of radiation dose at a given point using special radiation monitoring and measuring devices such as thermoluminescent dosimeters, solid state diode probes, film dosimetry, or special dosimetry probes. The results of the measurements are utilized to either accept or revise the current treatment plan.

As most patients will not require special dosimetry measurements, explanation of medical necessity may be required. This code is generally reported once for each distinct dose location that is measured. An individual dose location is typically measured once in the field delivery course. A second measurement at the same location would not be separately billed unless there was a significant change in the treatment.

CUAC Response 2:

Some institutions have employed routine dosimetry measurements on all patients or all fields. This is not an appropriate use of CPT code 77331; Special dosimetry (e.g., TLD, microdosimetry) (specify), only when prescribed by the treating physician, nor is it an example of good medical practice. If proper physics and dosimetry procedures are being followed, there is no reason to measure the output for most patients. The code exists to allow for measurements where there is a clinical indication or something unusual about the treatment that may approach the confidence limits for calculation. For example, the central axis dose need not be measured for a 10 by 10 portal (even with custom blocking), but might be required for an extremely small (or large) irregular treatment area. Use should be for special situations such as dose at abutting fields, unusually small fields, verifying dose under bolus, etc.

The opinions referenced are those of members of the ASTRO Code Utilization and Application Committee based on their coding experience and they are provided, without charge, as a service to the profession. They are based on the commonly used codes in radiation oncology, which are not all inclusive. Always check with your local insurance carriers, as policies vary by region. The final decision for coding for any procedure must be made by the physician, considering regulations of insurance carriers and any local, state or federal laws that apply to the physicians practice. ASTRO nor any of its officers, directors, agents, employees, committee members or other representatives shall have any liability for any claim, whether founded or unfounded, of any kind whatsoever, including but not limited to any claim for costs and legal fees, arising from the use of these opinions.

All CPT code descriptors have been taken from Current Procedural Terminology (CPT®) 2007 copyright 2006 American Medical Association. All rights reserved.

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