The HCPCS/CPT code(s) may be subject to Correct Coding Initiative (CCI) edits.  This information does not take precedence over CCI edits.  Please refer to CCI for correct coding guidelines and specific applicable code combinations prior to billing Medicare.

It is expected that the coding, billing, and documentation instructions as detailed in "Radiation Oncology: Radiation Therapy Treatment and Complementary Services" that apply to the services provided with IMRT are also followed where applicable. 

Intensity Modulated Radiation Therapy (IMRT) is a new technology in radiation oncology that delivers radiation more precisely to the tumor while relatively sparing the surrounding normal tissues.  When the tumor is not well separated from the surrounding organs at risk, such as what occurs when a tumor wraps itself around an organ, there may be no combination of uniform intensity beams that will safely separate the tumor from the healthy organ.  In such instances, adding intensity modulation allows more intense treatment of the tumor, while limiting the radiation dose to adjacent healthy tissue.

IMRT is an advanced form of three-dimensional conformal radiation therapy (3D CRT) that allows for varying intensities of radiation to produce dose distributions that are more conformal than those possible with standard 3D CRT.  In IMRT, the beam intensity is varied across the treatment field.  Rather than being treated with a single, large, uniform beam, the patient is treated instead with many very small beams; each can have a different intensity.  By cross firing the tumor with these beams, the physician delivers a relatively uniform radiation dose to the tumor, but protects sensitive, surrounding tissue from high-dose radiation.

The beam intensities are determined by a computer-based optimization process called “inverse planning,” in which specific dose constraints for the planned treatment volume (PTV) and surrounding structures are entered and a dose distribution is developed.  The gross tumor volume (GTV), the PTV, and surrounding normal tissues are then identified by a contouring procedure, and the optimization samples the dose with a grid spacing of 1.0 centimeter or less.

Delivery of IMRT may employ a multi-leaf collimator (MLC) with leaves that project to a nominal 1 centimeter or less at the treatment unit isocenter.  The MLC may be used in a dynamic (DMLC) or segmented mode (SMLC) (mean segments per gantry position or ‘steps’ required to meet IMRT delivery is 5) to create the three-dimensional, intensity-modulated dose distribution.  The exact delivery method is not restricted as long as the particular technique chosen has the ability to model the highly modulated intensity patterns that result from the planning process described above.  However, the use of a MLC to produce simple one-dimensional ramp intensity distributions is excluded because the inverse planning process is not expected to produce these intensity patterns.

IMRT delivery imposes a more stringent requirement than conventional radiation therapy in terms of accounting for patient position and organ motion.  Methods that account for organ motion include but are not limited to: 1) use of published studies on organ movement when developing the PTV, 2) image guided adaptive radiotherapy (e.g., ultrasound guided or portal image guided setup with implanted fiducial markers), and 3) respiratory gating of diaphragm movement for thoracic and upper abdominal sites.

Compensator based beam modulation treatment delivery (0073T), on the other hand, utilizes precision, customized, milled physical compensators to modulate the intensity of the radiotherapy beam. These compensators are milled separately for each patient and for each gantry position of the radiotherapy plan and cannot be used for multiple patients. Compensating filters perform the same function of modulating the intensity of the radiotherapy beam as the multileaf collimator described above. As a result, an MLC is not required if compensator based IMRT is utilized. Since compensator based IMRT does not use separate, individual segments per gantry position, a minimum of three separate gantry positions and compensators must be utilized and documented.

The decision process for using IMRT requires an understanding of accepted practices that take into account the risks and benefits of such therapy compared to conventional and 3D conformal treatment.  While IMRT technology may empirically offer advances over conventional or 3-dimentional conformal radiation, a comprehensive understanding of all consequences is required before applying this technology.

IMRT is not a replacement therapy for conventional radiation therapy methods.  Therefore, there must be documented rationale of the advantage of IMRT versus the use of other radiation therapy methods in the medical record of each patient for whom IMRT is provided.  Examples of such rationale could include:

• At least three critical dose limiting structures adjacent to, but outside the PTV are sufficiently close as seen on the dose volume histogram (DVH) and require IMRT to assure for safety and morbidity reduction.
• An immediately adjacent volume has been irradiated and abutting portals must be established with high precision.
• Gross Tumor Volume (GTV) margins are concave or convex and in close proximity to critical structures that must be protected to avoid unacceptable morbidity.
• Non-IMRT techniques would increase the probability of grade 2 or grade 3 radiation toxicity in greater than 15 percent of radiated similar cases.
• The volume of interest is in such location that its parameters are not assessed by simple two dimensional imaging techniques but rather by three dimensional reconstructions.
• The tumor tissue lies in areas associated with target motion caused by cardiac and pulmonary cycles, and the IMRT is necessary in order to protect adjacent normal tissues.

Special Dosimetry Calculation (CPT 77331)

Special dosimetry is performed once per port when the physician determines that it is necessary to have a measurement of the amount of radiation that a patient has actually received at a given point.  The results are then used to verify or modify the current treatment plan.  This service can only be billed when prescribed by the treating physician. 

This use of special radiation, measuring and monitoring devices such as thermoluminescent dosimeters, special dosimetry probes, film dosimetry, solid state diode probes, or other methods for calculating the specific dosage at a given point, is done at the direct request of the radiation oncologist.  Although these particular services are often recognized and described as physics services, they always contain significant physician involvement.  When the physician either performs the service directly or is directly involved in the design or final selection process and can thoroughly document this involvement, these services are to be submitted as a professional charge by the radiation oncologist.  Direct involvement and documentation are the key factors.

This procedure is not to be routinely performed each time the patient is treated.  The use of this procedure should correspond with the level of complexity reflected in the clinical treatment planning.  This service should not be reported more than once per port per course of therapy. The usual frequency of special dosimetry is between one to six services per course of therapy.  Documentation in the medical records must justify the frequency and medical necessity of the service and must be signed by the medical radiological physicist and the radiation oncologist.

Treatment Devices (77332-77334)

There are many different types of treatment devices used in the successful delivery of therapeutic radiation. A patient's treatment course may require one or more devices. The use of a device is based upon the clinical judgment of the radiation oncologist and is influenced by the patient's anatomy and disease state.

The general categories of treatment devices include:

• Beam-shaping devices - may be placed in the external radiation beam to modify its shape to either contour the beam around target structures or to shield normal tissues. These devices are usually referred to as blocks and may be constructed from alloy, such as cerrobend, or may utilize multileaf collimation (MLC).
• Immobilization devices - are used to ensure daily reproducibility of patient set-up and restrict patient movement during treatment. Examples of these devices include thermoplastic face and body masks, bite-block head holders, Styrofoam body casts, and customized positioning devices such as breast boards. Positioning and restraining devices may be reported separately from beam-modifying devices. Products used for patient comfort, such as pillows, pads, cushions and non-fabricated headrests, should not be reported as treatment devices.
• Beam-modifying devices - include wedges, compensators and bolus.
• Shielding devices - include bite blocks, eye shields and testicular shields.

Treatment devices are to be billed at the onset of the treatment. They may be billed again later in the course of treatment if additional or new devices are required.

A specific treatment device is reported only one time for the entire course of treatment regardless of the number of times the device is used. However, multiple services may be billed on a single date. The typical course of intensity modulated radiation therapy may consist of more than eight professional codes for devices.  Please note that reporting of units in excess of eight may require supporting documentation.  Services for treatment devices (CPT 77332-77334) are not to be billed at each Radiation Treatment delivery encounter.

There are three different levels of treatment devices:

77332 - Treatment devices, design and construction; simple:

• Simple block - simple hand or pre-made blocks
• Simple pre-fabricated bolus sheet
• Independent jaws or asymmetrical collimation

77333 - Treatment devices, design and construction; intermediate:

• Multiple blocks - 3 or more hand or pre-made blocks
• Multiple straight edge blocks
• Stents
• Bite blocks
• Special multi use bolus
• Beam splitter blocks

77334 - Treatment devices, design and construction; complex:

• Customized Irregular Cerrobend or MLC blocks
• Special shields for eyes and testicles
• Tissue compensators, dynamic or hard wedges
• Molds or casts
• Customized single use bolus such as wax molds conformed to a particular patient body part
• Alpha Cradles
• Vac Loc Bags
• Aquaplast
• Custom electron lead cutout

Pre-made, multiple-patient use, standard shaped blocks such as beam splitter blocks, two or four corner pelvis blocks, and midline cord blocks do not constitute complex custom blocks. These would be billed at a simple or intermediate level and do not affect the level of treatment management.

When a patient has a combination of a wedge, a compensator, bolus or port block covering the same treatment portal, this would be billed as a single complex treatment device rather than a separate charge rendered for each of the individual items. If devices of two separate levels of complexity are used for the same treatment portal, only the highest level of complexity should be billed. It is the provider's responsibility to determine the code that most accurately describes the devices employed.

Positioning and restraining devices may be reported separately from beam-modulating devices. Products used for patient comfort (e.g., pillows, pads, cushions) are not to be reported as treatment devices. One immobilization device is typically reported for a volume of interest. Immobilization devices may be reported separately from beam-modifying devices.

Only one beam-altering (shaping or modifying) treatment device is billable per port for the professional service. However, significant changes in the shape of the port(s), beam direction or size (i.e. boosts) may require additional device codes.  More than one device may be reported for a single port in the rare instance that each device is custom designed and medically necessary (e.g., customized single use bolus and MLC blocking). In addition, minor port changes do not constitute an additional treatment device.

The technical portion may be reported for the construction of each device at the appropriate level of complexity.

It is expected that the documentation, coding, and utilization of treatment devices would be in keeping with the "community standard of practice" as delineated by current practice guidelines and reviewed by practicing physicians in Radiation Oncology.

It is the provider's responsibility to determine the code that most accurately describes the devices employed. In all levels of complexity, the radiation oncologist must be directly involved in the design, selection, and placement of any of the devices. The selection and use of any treatment device requires medical necessity and a written and signed order for each device. The radiation oncologist's signature on the simulation work product and the isodose work product serves as adequate documentation to support the physician's participation in the design, fabrication and correct usage of treatment devices. The medical record documentation must clearly justify the level of code billed and the physician involvement.

Intensity modulated radiotherapy plan (77301) should be billed once per treatment course per treatment volume.  Simultaneous or planned sequential treatment of multiple targets within a region (e.g., multiple lesions of the brain or prostate and seminal vesicles) should be considered as a single plan.  Procedure code 77301 should be billed to correspond with the date that the plan was approved by the radiation oncologist or physicist.

Do not report the following CPT codes when the services are directly linked to and performed as part of developing an IMRT plan that is reported using CPT code 77301 even if the services are performed on different dates:

Payment for 77301 does not include payment for treatment devices, design and construction (codes 77332-4) when furnished on the same day.  These services should be billed in addition to code 77301 and appended with the -59 modifier.

Procedure code 77331 may be reported once per port for special dosimetry.

Treatment devices are to be billed at the onset of the treatment. They may be billed again later in the course of treatment if additional or new devices are required. One set of treatment devices may be allowed per separate port when radiation therapy is started. A pair of mirror image opposing ports, ports directing parallel beams (e.g., anterior-posterior or left lateral-right lateral pairs) are considered, for billing purposes, one port. This is true, regardless of the complexity level of the devices used to create the ports. However, if these devices are significantly different from each other, then payment may be allowed for each pair of devices. Multiple treatment devices may be billed during a course of therapy if documentation substantiates multiple treatment fields/portals, the use of custom-made devices, and/or the necessity of replacement devices.

Documentation

Documentation must clearly state indications, rationale and medical necessity for IMRT.  Documentation must be legible, maintained in the patient's medical record, and made available to Medicare upon request.

The following documentation must be in the medical record:

• The prescription, defining the goals and requirements of the treatment plan, including the specific dose constraints for the target(s) and nearby critical structures;
• A statement by the treating physician documenting the medical necessity for performing IMRT on the patient in question, rather than performing conventional or 3-dimensional treatment planning and delivery. This should include documentation of the need to provide protection of at least three vital structures;
• A signed IMRT inverse plan that meets prescribed dose constraints for the planning target volume (PTV) and surrounding normal tissue using either dynamic multi-leaf collimator (DMLC), segmented multi-leaf collimator (SMLC) (average number of ‘steps’ required to meet IMRT delivery is 5) or inverse planned IMRT solid compensators to achieve intensity modulation radiation delivery;
• The target verification methodology which must include all of the following:
  • documentation of the clinical treatment volume (CTV) and the planning target volume (PTV)
  • documentation of immobilization and patient positioning
  • means of dose verification and secondary means of verification;
  • an independent check of the monitor units (MU’s) generated by the IMRT treatment plan, prior to the patient’s first treatment;
  • fluence distributions re-computed in a phantom; and
  • plan to account for structures moving in and out of high and low dose regions created by respiration.  Voluntary breath holding is not considered appropriate and the solution for movement can best be accomplished with gating technology.

All of the above documentation should be available to and reviewed by the radiation oncologist or physicist when the plan is approved.

Documentation to verify appropriate use of a multi-leaf collimator should include at least 5 ports or fluence diagrams.

Documentation to verify appropriate use of a compensator system (0073T) should include, but not be limited to, a photograph of the compensator set-up, compensator fluence diagrams for each port of therapy and documentation of at least 3 ports per site of treatment.

When intensity modulated radiotherapy plan (77301) is billed more than once for the same tumor, medical record documentation must support the medical necessity of the additional plan(s) and be available to the contractor upon request.

Please note that reporting more than eight units for treatment device services (CPT 77332, 77333, and 77334) may require supporting documentation.