Summary & Overview
CPT 77439: Ultrasound Guidance for Surface Radiation Therapy Field Placement
CPT code 77439 describes ultrasound imaging used to guide placement of surface radiation therapy (SRT) fields for cutaneous tumors. It is reported once per course of treatment and only in addition to the primary SRT delivery code. Nationally, this code captures a targeted imaging service that supports precision in localized radiation for skin cancers and superficial lesions, with implications for billing consistency and documentation standards across payers.
Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of what the code represents, expected sites of service, and the clinical context for use. The publication provides benchmark framing and payer coverage considerations where available, notes on how the code is typically reported in relation to primary SRT delivery services, and pointers to policy language and documentation elements that commonly affect reimbursement decisions. The content highlights the role of ultrasound-guided positioning in improving field accuracy and treatment reproducibility for cutaneous radiation therapy. Data not available in the input is explicitly identified, and readers are directed to payer policy sources for plan-specific coverage rules and billing instructions.
Billing Code Overview
CPT code 77439 represents ultrasound guidance for placement of surface radiation therapy (SRT) fields directed at cutaneous tumors. The service is used to image and confirm field placement for SRT and is reported once per course of treatment in addition to the primary SRT delivery code.
Service type: Ultrasound-guided setup for surface radiation therapy
Typical site of service: Outpatient radiation oncology clinics or ambulatory procedural settings where surface radiation therapy is delivered
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult with a biopsy-proven primary cutaneous malignancy such as basal cell carcinoma, squamous cell carcinoma, or early-stage cutaneous melanoma located on a cosmetically sensitive area (face, ear, scalp). The patient is referred to a dermatologic radiation oncology or surface radiation therapy (SRT) clinic for definitive superficial radiation therapy when surgery is contraindicated, declined, or would cause unacceptable functional/cosmetic outcomes.
The clinical workflow begins with consultation, review of the pathology report and lesion mapping, and determination of candidacy for SRT. Prior to the first SRT delivery session, the provider performs ultrasound imaging to identify tumor depth and lateral extent, mark field boundaries, and select applicator size and energy. Ultrasound-guided field placement is performed once per course of treatment and documented in the medical record, including images, measurements, and justification for field selection. The primary SRT delivery code(s) are billed separately for each treatment fraction; 77439 is reported a single time per course in addition to the primary delivery service code. Care coordination includes informed consent, simulation/planning notes, treatment delivery records, and follow-up visits to assess response and toxicity.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
25 | Significant, separately identifiable evaluation and management service by the same physician on the same day of a procedure |