The goal of radiation therapy has always been to treat the majority of the tumor, most of the time, with the dose prescribed. Imprecise targeting, however, meant that healthy tissue and important organs could be damaged. Beginning in the 1950s, port films were used to improve patient positioning and obtain an approximate measurement of the target.

With the advent of commercial intensity-modulated radiation therapy in 2000, it became possible to deliver a precise beam, but not to hit a target that could move from day to day. Port films were used to position the patient correctly and locate the tumor. At the same time, stereotactic radiosurgery and stereotactic radiotherapy targeted tumors using kV x-rays with infrared tracking and gold fiducial markers (inserted surgically). This allowed the intense beams from linear accelerators to be aimed precisely.

These advanced systems used in linear accelerators are now used in image-guided radiation therapy (IGRT) to treat tumors. Fluoroscopy, CT, MV x-ray, and kV x-ray images are obtained daily to ensure that the treatment beam hits the target while sparing normal tissue.


In 2004, the only American Medical Association Current Procedural Terminology (CPT) code available to use in billing payors for localization of the target volume prior to IGRT was 76950, ultrasonic guidance for placement of radiation therapy fields. This code covers both the technical and professional components of reimbursement, but for global billing, the physician must be present during localization and must submit a report.

Note: Of 360 patients; tabulations are based on 20% receiving x-ray kV MV at 25 fractions; 30% CT at 30 fractions; 10% fluoroscopy at 6 fractions, 20% ultrasound (for prostate only) at 38 images per patient treated.

On January 1, 2005, Healthcare Common Procedure Coding System (HCPCS) code C9722, stereoscopic kV x-ray imaging with infrared tracking for localization of target volume, became available for hospital use. There was no professional component and freestanding centers could not use this code. The other codes, 77417-port films, 76370-CT guidance for placement of radiation therapy fields, 76000-fluoroscopy, and 76950-ultrasonic guidance for placement of radiation therapy fields have been in existence for some time. CPT code 77417 is for the technical component of therapeutic radiology port films; no professional component is included. Both technical and professional reimbursement, with up to an hour of the physician’s time, are available for CPT code 76000, fluoroscopy (separate procedure).

CPT code 76370, computed tomography guidance for placement of radiation therapy fields, covers only the technical component for cone-beam CT localization, with no professional reimbursement for the radiation oncologist. Code C9722 is usable only by hospitals and contains no professional component.

On January 1, 2006, HCPCS code C9722 will be replaced by CPT code 77421, stereoscopic x-ray guidance for localization of target volume for the delivery of radiation therapy. The new code, fortunately, incorporates both professional and technical components and will cover the imaging procedure with or without infrared tracking and using either MV or kV x-ray. In addition, physicians and freestanding imaging centers, not just hospitals, can use the 77421 code.


The 77421 code also allows providers with electronic portal imaging device (EPID) systems to bill payors for reimbursement, but additional steps will be needed and only millimeter accuracy will be acceptable. The code was specifically designed to provide enhanced imaged guidance to millimeter accuracy. A surgeon or radiation oncologist will implant fiducial markers or add a marker system. The patient will then undergo imaging, usually with CT for a base image to use for future image comparison. The resulting images will be sent to the physician who will develop the treatment plan. The radiation oncologist will then order the IGRT procedures. The imaging department or center must have some type of patient-positioning system available. The patient will be placed on the table and a set of images will be acquired using the EPID system and compared with the existing image; any necessary alignment shifts will then be performed and the patient will be treated.

Note: Tabulations for this chart are based on same patient mix as for Table 1.

The documentation needed for the 77421 code consists of having the therapist record exactly what was performed, accompanied by the patient’s name, the date, and the therapist’s signature. The documentation must be labeled as IGRT (with the type of procedure); as stereoscopic x-ray guidance for localization of target volume for the delivery of radiation therapy; and with the applicable procedural information (who, what, when, where, and why). The radiation oncologist will review the images daily and give feedback to the therapists concerning registration and any required modifications.

James E. Hugh III, MHA, is senior vice president, AMAC®, Marietta, Ga.