D714B9Z
Brachytherapy Lymphatics, Axillary to None with Iodine 125 (I-125), Low Dose Rate (LDR) Approach
Procedural Specifications
| Clinical Axis | Detail Definition |
|---|---|
| Section | D Radiation Therapy |
| Body System | 7 Lymphatic and Hematologic System |
| Operation | 1 Brachytherapy |
| Body Part | 4 Lymphatics, Axillary |
| Approach | B Low Dose Rate (LDR) |
| Device | 9 Iodine 125 (I-125) |
| Qualifier | Z None |
Procedure Overview
Brachytherapy of the lymphatic and hematologic system involves placing a radioactive source directly into or adjacent to lymphatic tissue, delivering a concentrated, localized dose while sparing tissue farther from the source. This is less common than external beam treatment for this body system but may be used for localized nodal disease where direct source placement offers better dose control, or in combination with surgery for residual microscopic tumor at a nodal bed.
The radioactive material can be left in place temporarily and removed after a calculated dose is delivered, or in some cases placed permanently as small seeds that decay over time. The approach is chosen when the anatomic target allows safe, direct access for source placement.
Anatomy & Axis Detail
Lymphatics, Axillary
Brachytherapy of the axillary lymphatics places a radioactive source directly within or adjacent to nodal tissue in the armpit, most often used to deliver a targeted boost to a residual or recurrent nodal deposit after surgery or prior external beam treatment, when re-treating the entire axilla externally would risk excessive cumulative dose to the brachial plexus and skin. Source placement in this compact space requires care to avoid the axillary vessels and nerves that pass through the region, and implants are frequently performed intraoperatively or under image guidance to ensure accurate positioning relative to the nodal bed. This localized approach concentrates dose on a limited volume while sparing the broader shoulder and chest wall from additional exposure. Documentation should specify the focal axillary site treated and any relevant prior therapy.
Modality Qualifier: Low Dose Rate (LDR)
Low Dose Rate (LDR) denotes brachytherapy using a source of lower activity that remains implanted or applied over an extended period, from many hours to a few days, exploiting continuous low-level irradiation for tumor control. This differs from High Dose Rate (HDR), which compresses the same general goal into brief, higher-intensity sessions, and LDR is often chosen for permanent seed implants such as certain prostate treatments.
Isotope: Iodine 125 (I-125)
Iodine-125 is a low-energy, low-dose-rate radioisotope most often loaded into small permanent seeds implanted directly into tissue, commonly for early-stage prostate cancer or ocular tumors via plaque brachytherapy. Its longer half-life (about 60 days) gives a slower, more protracted dose delivery than Pd-103 or Cs-131, which is the key distinction among the permanent-seed isotopes.
Coding & Documentation
Coders confirm brachytherapy by finding documentation of a radioactive source being implanted, inserted, or applied directly at or near the lymphatic target, along with whether the source was temporary or permanent, which determines the correct approach and qualifier values. The radiation oncology or interventional procedure note should specify the isotope, source configuration, and duration of placement.
A frequent mistake is confusing a temporary applicator left in place for a planned removal with a permanent seed implant, which changes both the qualifier and the expected follow-up documentation. Coders should also verify the treated body part matches the nodal region named in the operative note rather than assuming it based on the underlying diagnosis.