Summary & Overview
CPT 77789: Low–Dose–Rate Surface or Interstitial Brachytherapy
CPT code 77789 represents low–dose–rate (LDR) brachytherapy procedures in which a radioactive source is applied directly to the surface of the target area using surface applicators, needles, seeds, or suspensions. This code captures a focused radiation delivery technique used for localized malignancies or lesions where direct surface or interstitial placement of sources is clinically appropriate. Nationally, LDR brachytherapy is a specialized, resource‑intensive service with implications for procedural coding, facility site-of-service designation, and payer coverage policies.
Key payers considered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The report outlines typical sites of service and clinical context, and provides benchmarking and policy-relevant highlights commonly reviewed by health plans and provider billing teams.
Readers will learn what CPT code 77789 denotes clinically and operationally, how it is commonly performed, and which payers are most frequently involved in coverage decisions. The publication summarizes billing considerations, common modifiers used with procedural codes (listed separately), and the types of facilities where the service is delivered. Data not available in the input are noted where applicable. The content is intended for billing managers, compliance officers, and clinical leaders seeking a concise national overview of this brachytherapy procedure code.
Billing Code Overview
CPT code 77789 describes the application of a low–dose–rate radioactive source directly to the surface of a target body area. The procedure uses surface applicators, needles, seeds, or suspensions to deliver brachytherapy at a low dose rate to a localized treatment site.
Service Type: Low–dose–rate brachytherapy (surface or interstitial application)
Typical Site of Service: Outpatient procedure room, ambulatory surgery center, or hospital outpatient department, where localized radiation sources are applied directly to the treatment surface or implanted temporarily/permanently.
Clinical & Coding Specifications
Clinical Context
A 68-year-old patient with a superficial squamous cell carcinoma of the scalp is scheduled for low–dose–rate (LDR) brachytherapy. The radiation oncology team uses surface applicators to place a temporary radioactive seed suspension directly on the lesion surface for several days to deliver a concentrated local dose while sparing surrounding normal tissues. The clinical workflow includes consultation and simulation with immobilization and surface mapping, applicator selection and placement by the radiation oncologist (often in a procedure suite or operating room), radiation physics verification of source activity and dwell times, short inpatient or outpatient monitoring during LDR delivery as required by institutional protocols, removal of applicators/seeds after prescribed dose delivery, and follow‑up visits to assess local control and toxicity.
Typical site of service: hospital outpatient department, ambulatory radiation oncology center, or procedure room in a hospital where brachytherapy sources and physics oversight are available.
Typical patient scenario: an elderly patient with a localized skin malignancy or mucosal lesion not amenable to wide local excision due to cosmetic or functional concerns, treated with LDR surface brachytherapy using needles, seeds, or surface applicators under direct supervision of a radiation oncologist and medical physicist. Monitoring for acute skin reaction and radiation safety precautions are part of the workflow.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 |