Radiology Coding Alert

Radiation oncology coders working with practices that perform complex radiation treatments often wonder when they can bill 3-D simulation-aided field setting and when they should use complex simulation.

The organization of the CPT manual doesn't make things any easier because both CPT 77290 (Therapeutic radiology simulation-aided field setting; complex) and 77295 (... three-dimensional) are indented under the same heading. The trick with these two codes is to realize that, for most payers, simulation (simple, intermediate or complex) is allowed in addition to 3-D in order to prepare the patient and to confirm the accuracy of treatment fields.

"The only restriction is reporting more than one 'simulation category code' on the same day," says Deborah I. Churchill, president and founder of Churchill Consulting Inc., an auditing and electronic coding consulting firm in Killingworth, Conn.

"A simple simulation (77280) is reported if only an orthogonal pair of films is taken," Churchill says, "while a complex simulation (77290) is reported if custom immobilization is constructed or if contrast is used." Direct physician supervision is required in both cases.

Complex simulation 77290 refers to situations in which there are three or more treatment areas and/or rotation or arc therapy is prescribed. Complex simulation requires complex blocking, special wedges or compensators, custom shielding blocks, complex immobilization or multileaf collimation.

When appropriate, complex simulation may also include brachytherapy source verification; hyperthermia probe verification; contrast materials, with or without fluoroscopy; and tangential ports, oblique fields, rotational or special beam considerations.

On the other hand, 77295 moves into the realm of treatment planning. "Although this service is listed with the simulation codes in CPT, it is perhaps better defined as a 3-D treatment plan," says Cindy Parman, CPC, CPC-H, RCC, co-owner of Coding Strategies Inc., an Atlanta-based coding and consulting firm.

This code describes computer-generated three-dimensional (3-D) reconstructions of tumor volume and surrounding critical normal tissue structures. 3-D simulation requires the use of CT, MRI, PET or ultrasound technologies and uses multiple beams for treatment, each having a single beam weight, Parman says.

In brief, the critical tissues or structures that youre protecting drive the decision to employ 3-D simulation as much as, or more than, the challenging tumor placement and/or structure that youre targeting, Parman says.

Experts concur that 77295 may be billed once per treatment course, per treatment volume.

The 3-D treatment planning system must fulfill several highly specialized functions before one may appropriately use the 3-D code. It goes almost without saying that the treatment planning system must be capable of performing 3-D modeling of the tumor and surrounding critical anatomic structures, Parman says.

Churchill says the 3-D system must also be able to

provide a beams-eye view (BEV). That is, it must demonstrate a three-dimensional representation of the radiation doses to the tumor volume and normal tissues.

compare doses to critical or sensitive structures (dose volume histograms, or DVH) by producing a 3-D isodose plan.

design correctly shaped apertures or custom shielding, which will result in DRRs (digitally reconstructed radiographs).

Evaluate and compare all other and concurrent treatment plans.

Finally, the documentation generated by the 3-D system software requires a permanent record of computer-generated 3-D tumor volume and critical structures (or critical area reconstruction). The documentation checklist also includes a 3-D representation of dose distribution in the form of dose clouds and/or dose volume, histograms of volume of interest, and critical structures, Churchill says. The documentation should be signed (on paper or electronically) and dated by the radiation oncologist and maintained in the patient chart.

The 3-D simulation code (77295) precludes the use of 77305-77315 (Teletherapy, isodose plan [whether hand or computer calculated]; simple, intermediate or complex) for the "same" volume.

When 3-D simulation is required and the medical-necessity guidelines are met, the radiation oncologist must gather additional electronic data in order to plan treatment to the volume of interest.

In most instances, a pre-CT simulation is performed to prepare the patient for 3-D treatment planning, Churchill says. At this encounter, she says, the patients position is established, custom immobilization may be constructed, and a tentative central axis is established that will be referenced on the CT.

The radiologist then performs a CT for treatment planning. If this procedure is performed on a dedicated CT simulator in the radiology department, 76370-TC (Computed tomography guidance for placement of radiation therapy fields; technical component) should be reported. Following the acquisition of the CT data, the 3-D treatment planning will be performed. "There is no professional interpretation, and therefore no professional component for this procedure," Parman notes.

Following the approval of the 3-D treatment plan, the portal arrangement and conformal shielding must be confirmed to ensure accurate treatment delivery. A separate simulation procedure will be scheduled. The patients original position will be re-established, and adjustments from the tentative isocenter will be made. The conformal block placement will be confirmed relative to the DRRs.

This particular simulation may be reported at the complex level (77290), Churchill says. Of course, direct physician supervision is required, and a simulation note should be available summarizing the procedure.