Summary & Overview
CPT 20555: Interstitial Radioelement Application (Brachytherapy)
CPT code 20555 represents interstitial radioelement application, commonly known as brachytherapy, used to treat localized cancers such as prostate, cervix, and breast cancer. The procedure places radioactive seeds or sources directly into tumor tissue via implanted tubing or catheters, delivering high-dose radiation to the target while limiting exposure to surrounding healthy tissue. Nationally, this code is important for tracking utilization of specialized radiation oncology services and for aligning billing with clinical practice in oncology care.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for the procedure, typical service locations, and the billing scope associated with CPT code 20555. The publication summarizes common modifiers associated with radiation therapy billing, highlights considerations for site-of-service coding, and outlines what to expect in payer coverage patterns at a national level. It also provides guidance on where to look for policy updates and reimbursement discussions relevant to interstitial brachytherapy.
This piece is intended for coding professionals, radiation oncology clinicians, and policy analysts seeking an authoritative snapshot of CPT code 20555, its clinical role, and its relevance to national payer coverage and billing practices.
Billing Code Overview
CPT code 20555 describes interstitial radioelement application (brachytherapy), a targeted radiotherapy technique in which radioactive seeds are placed within or adjacent to tumor tissue. The procedure involves inserting small tubes into which radioactive seeds are placed either immediately or at a later encounter; the seeds emit localized radiation that damages or destroys cancer cells.
Service type: Radiation therapy — interstitial brachytherapy
Typical site of service: Hospital-based radiation oncology departments, freestanding radiation oncology centers, or ambulatory surgical centers, depending on clinical setting and institutional capability.
Clinical & Coding Specifications
Clinical Context
A 68-year-old male with intermediate-risk localized prostate adenocarcinoma is scheduled for interstitial brachytherapy. The radiation oncology team performs pre-procedure planning including transrectal ultrasound imaging, prostate volume assessment, and treatment planning to determine seed number and placement. On the day of service the patient receives conscious sedation; the clinician inserts hollow needles or applicator tubes through the perineum into the prostate under ultrasound guidance and places radioactive seeds (permanent low-dose-rate seeds) into the prostatic tissue. Post-implant imaging (CT or ultrasound) is obtained to verify seed placement and dosimetry. The typical site of service is an outpatient hospital or ambulatory surgery center within a radiation oncology department. The clinical workflow often involves a multidisciplinary team: urology for biopsy/sampling and referral, radiation oncology for planning and implant, medical physics for seed ordering and dosimetry, and nursing for peri-procedural care. Recovery includes short observation and outpatient follow-up for urinary, rectal, and sexual function monitoring.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the physician’s professional services separate from technical facility services when applicable (e.g., physician interpretation/planning billed separately). |