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Official Description

Therapeutic radiology simulation-aided field setting; simple

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

Therapeutic radiology simulation-aided field setting is a crucial procedure in the field of radiation oncology, aimed at accurately identifying both normal and abnormal anatomical structures within the targeted treatment area. This process involves the acquisition of images and data that are essential for planning effective radiation therapy. During the simulation, a radiation oncologist or a qualified healthcare professional employs specialized simulation equipment, which may include dedicated simulators, radiation treatment units, or diagnostic X-ray machines. The primary goal of this procedure is to establish the optimal treatment position for the patient, ensuring that the radiation is delivered precisely to the intended area while minimizing exposure to surrounding healthy tissues.

In the course of the simulation, several key steps are undertaken. These include the design of immobilization devices, if necessary, to keep the patient in a stable position throughout the treatment. Localization lasers are utilized to align the patient accurately, and the skin is marked with targeting markers or tattoos to provide visual references for the radiation delivery. The oncologist visualizes the treatment ports or fields in relation to anatomical landmarks, which is critical for effective treatment planning. Additionally, all parameters recorded during the simulation are meticulously documented to ensure that the treatment plan is based on accurate and comprehensive data. The specific CPT® code 77280 is designated for reporting the simulation of a single area of interest, which may involve a single port or simple parallel opposed ports with minimal or no blocking, distinguishing it from more complex simulation procedures that are reported with other codes.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The therapeutic radiology simulation-aided field setting is indicated for various clinical scenarios where precise localization of treatment areas is essential. The following conditions may warrant the use of this procedure:

  • Identification of Tumors: To accurately locate and define the boundaries of tumors within the treatment area.
  • Assessment of Anatomical Structures: To evaluate normal and abnormal anatomy that may affect treatment planning.
  • Preparation for Radiation Therapy: To establish the optimal treatment position and parameters prior to the initiation of radiation therapy.

2. Procedure

The procedure for therapeutic radiology simulation-aided field setting involves several critical steps to ensure accurate treatment planning. Each step is designed to facilitate the precise delivery of radiation therapy.

  • Step 1: Equipment Setup The simulation begins with the setup of the necessary equipment, which may include a dedicated simulator, radiation treatment unit, or diagnostic X-ray machine. This equipment is calibrated and prepared to capture the required images and data from the targeted treatment area.
  • Step 2: Patient Positioning The patient is positioned in a manner that optimizes access to the treatment area. This may involve the use of immobilization devices to ensure that the patient remains still throughout the simulation process.
  • Step 3: Use of Localization Lasers Localization lasers are employed to align the patient accurately. These lasers project reference points that help in achieving the correct positioning relative to the treatment area.
  • Step 4: Marking the Skin The skin is marked with targeting markers or tattoos. These markings serve as visual guides for the radiation delivery, ensuring that the treatment is directed precisely at the intended site.
  • Step 5: Visualization of Ports/Fields The oncologist visualizes the treatment ports or fields in relation to anatomical landmarks. This step is crucial for determining the most effective angles and positions for radiation delivery.
  • Step 6: Documentation Finally, all parameters recorded during the simulation are documented thoroughly. This documentation includes details about the patient's position, the equipment used, and any specific measurements taken, which are essential for developing an effective treatment plan.

3. Post-Procedure

After the therapeutic radiology simulation-aided field setting is completed, the patient may be provided with specific instructions regarding any necessary follow-up care. The documentation generated during the simulation will be reviewed to finalize the treatment plan. The oncologist will discuss the next steps in the radiation therapy process, including scheduling treatment sessions and any additional preparations that may be required. It is important for the patient to adhere to any guidelines provided to ensure the effectiveness of the upcoming radiation therapy.

Short Descr THER RAD SIMULAJ FIELD SMPL
Medium Descr THER RAD SIMULAJ-AIDED FIELD SETTING SIMPLE
Long Descr Therapeutic radiology simulation-aided field setting; simple
Status Code Active Code
Global Days XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC) 1 - Diagnostic Tests for Radiology Services
Multiple Procedures (51) 0 - No payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 0 - Payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Procedure or Service, Not Discounted when Multiple
ASC Payment Indicator Radiology service paid separately when provided integral to a surgical procedure on ASC list; payment based on OPPS relative payment weight.
Type of Service (TOS) 6 - Therapeutic Radiology
Berenson-Eggers TOS (BETOS) P7A - Oncology - radiation therapy
MUE 2
CCS Clinical Classification 211 - Therapeutic radiology
26 Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
GC This service has been performed in part by a resident under the direction of a teaching physician
TC Technical component; under certain circumstances, a charge may be made for the technical component alone; under those circumstances the technical component charge is identified by adding modifier 'tc' to the usual procedure number; technical component charges are institutional charges and not billed separately by physicians; however, portable x-ray suppliers only bill for technical component and should utilize modifier tc; the charge data from portable x-ray suppliers will then be used to build customary and prevailing profiles
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
LT Left side (used to identify procedures performed on the left side of the body)
X4 Episodic/focused services: for reporting services by clinicians who provide focused care on particular types of treatment limited to a defined period and circumstance; the patient has a problem, acute or chronic, that will be treated with surgery, radiation, or some other type of generally time-limited intervention; reporting clinician service examples include but are not limited to, the orthopedic surgeon performing a knee replacement and seeing the patient through the postoperative period
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
GW Service not related to the hospice patient's terminal condition
RT Right side (used to identify procedures performed on the right side of the body)
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
CR Catastrophe/disaster related
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
X5 Diagnostic services requested by another clinician: for reporting services by a clinician who furnishes care to the patient only as requested by another clinician or subsequent and related services requested by another clinician; this modifier is reported for patient relationships that may not be adequately captured by the above alternative categories; reporting clinician service examples include but are not limited to, the radiologist's interpretation of an imaging study requested by another clinician
SA Nurse practitioner rendering service in collaboration with a physician
Q5 Service furnished under a reciprocal billing arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
XP Separate practitioner, a service that is distinct because it was performed by a different practitioner
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
52 Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
PD Diagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days
PN Non-excepted service provided at an off-campus, outpatient, provider-based department of a hospital
Q0 Investigational clinical service provided in a clinical research study that is in an approved clinical research study
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2025-01-01 Changed Short Description changed.
Pre-1990 Added Code added.
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