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Official Description

Computed tomography guidance for stereotactic localization

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

Computed tomography guidance for stereotactic localization, represented by CPT® Code 77011, is a specialized imaging technique that utilizes computed tomography (CT) to accurately identify and localize lesions within the body. This procedure is essential in various medical contexts, particularly in neurosurgery and oncology, where precise targeting of lesions is critical for effective treatment. Stereotactic localization involves determining the exact position of a lesion by assigning specific coordinates—x, y, and z—relative to a defined point of reference. This method ensures that the lesion's position is maintained consistently throughout the imaging process. Initially, a baseline image is captured at a 0-degree angle, establishing a reference point. Subsequently, additional images are taken by adjusting the imaging detector or beams around this reference point in a controlled manner, both clockwise and counterclockwise, within specified angular limits. By applying basic geometric principles, the precise location of the lesion is calculated within a three-dimensional coordinate system, utilizing the paired images obtained in relation to the fixed origin. The use of CT imaging in this context is crucial, as it provides the necessary detail and accuracy to effectively locate the lesion and determine its coordinates for further medical intervention.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The procedure of computed tomography guidance for stereotactic localization is indicated for various clinical scenarios where precise localization of a lesion is necessary. The following conditions may warrant the use of this imaging technique:

  • Brain Tumors The procedure is often utilized in the identification and localization of brain tumors, facilitating targeted interventions such as biopsies or radiation therapy.
  • Lesions in Other Organs Stereotactic localization can be applied to lesions in other anatomical regions, including the lungs, liver, and spine, where accurate targeting is essential for treatment.
  • Guidance for Biopsy This imaging technique is frequently employed to guide needle biopsies, ensuring that the sampling is taken from the correct location within the lesion.
  • Radiation Therapy Planning It is also indicated for planning radiation therapy, allowing for precise delivery of radiation to the tumor while minimizing exposure to surrounding healthy tissues.

2. Procedure

The procedure for computed tomography guidance for stereotactic localization involves several critical steps to ensure accurate lesion localization. Each step is designed to enhance the precision of the imaging process.

  • Step 1: Initial Imaging The procedure begins with the acquisition of an initial CT image at a 0-degree angulation. This image serves as the baseline reference point for subsequent imaging and localization efforts.
  • Step 2: Image Acquisition at Angled Positions Following the initial imaging, additional images are obtained by moving the imaging detector or beams in a controlled manner around the center of rotation. This movement occurs both clockwise and counterclockwise, at specified degrees from the 0-degree position, allowing for a comprehensive view of the lesion from multiple angles.
  • Step 3: Coordinate Calculation Using the paired images captured during the previous steps, basic geometric principles are applied to calculate the precise location of the lesion within a three-dimensional coordinate system. This calculation is crucial for accurate localization and subsequent medical interventions.

3. Post-Procedure

After the completion of the computed tomography guidance for stereotactic localization, patients may be monitored for any immediate post-procedural effects, although the procedure itself is generally non-invasive. The results of the imaging will be analyzed to confirm the accurate localization of the lesion. Depending on the clinical context, further interventions such as biopsies or treatment planning for radiation therapy may be scheduled based on the findings. It is essential for healthcare providers to communicate the results to the patient and discuss any necessary follow-up actions or additional imaging that may be required.

Short Descr CT SCAN FOR LOCALIZATION
Medium Descr CT GUIDANCE STEREOTACTIC LOCALIZATION
Long Descr Computed tomography guidance for stereotactic localization
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) 9 - Concept does not apply.
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 Items and Services Packaged into APC Rates
ASC Payment Indicator Packaged service/item; no separate payment made.
Type of Service (TOS) 4 - Diagnostic Radiology
Berenson-Eggers TOS (BETOS) I2B - Advanced imaging - CAT/CT/CTA: other
MUE 1
CCS Clinical Classification 180 - Other CT scan
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.
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).
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
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.
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.)
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
MG The order for this service does not have applicable appropriate use criteria in the qualified clinical decision support mechanism consulted by the ordering professional
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
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
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
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
XP Separate practitioner, a service that is distinct because it was performed by a different practitioner
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
Action
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2013-01-01 Changed Guideline information changed.
2007-01-01 Added -
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