Summary & Overview
CPT 77307: Radiation Therapy Isodose Tangential Port Planning
CPT code 77307 captures the technical planning activity in external beam radiation therapy where a provider arranges tangential ports to achieve an isodose beam arrangement treating multiple areas at once and calculates dose based on cancer type and stage. This planning step is central to delivering targeted, evenly distributed radiation doses in complex treatment fields and influences treatment accuracy, patient safety, and downstream billing for radiation oncology services. Nationally, accurate use of 77307 matters for care coordination across cancer centers and for consistent documentation of radiation planning effort.
Key payers in payer-specific coverage and reimbursement discussions include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn the clinical context and service characteristics tied to the code, typical sites where the service is delivered, common modifiers associated with radiation therapy billing, and where input data is not available. The publication provides benchmarks and policy-relevant context for payers and providers, summing up how 77307 fits into broader radiation oncology service lines and coding workflows. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 77307 describes the provider's planning and arrangement of tangential ports to create an isodose beam arrangement for external beam radiation therapy directed at multiple areas simultaneously. The service includes calculation of the appropriate radiation dose based on cancer type and stage to ensure equal-intensity dose distribution across the treatment fields.
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Service type: Radiation therapy treatment planning and dosimetric arrangement for multi-field external beam therapy
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Typical site of service: Radiation oncology department or hospital-based outpatient radiation therapy suite
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient with multifocal cutaneous squamous cell carcinoma of the chest and adjacent axillary nodal involvement is referred for external beam radiation therapy. The radiation oncologist evaluates prior imaging and pathology, determines that simultaneous treatment of separate target areas is appropriate, and prescribes tangential beam arrangements with matched isodose patterns to cover both the chest wall and nodal basin. The clinical workflow includes simulation (CT-based treatment planning), contouring of targets and organs at risk, dosimetric calculations to achieve equal-intensity isodose coverage across fields, creation of tangential ports and beam arrangements, physics verification, and finally delivery of fractionated external beam therapy. Documentation in the medical record includes diagnosis, treatment intent, detailed planning parameters, calculated dose per fraction and total dose, and sign-off by the treating radiation oncologist. Billing uses 77307 to report the provider’s work arranging tangential ports and calculating the appropriate dose for simultaneous treatment of multiple areas.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing only the physician's professional planning/interpretation portion separated from technical services |