DG14B6Z
Brachytherapy Parathyroid Glands to None with Cesium 131 (Cs-131), Low Dose Rate (LDR) Approach
Procedural Specifications
| Clinical Axis | Detail Definition |
|---|---|
| Section | D Radiation Therapy |
| Body System | G Endocrine System |
| Operation | 1 Brachytherapy |
| Body Part | 4 Parathyroid Glands |
| Approach | B Low Dose Rate (LDR) |
| Device | 6 Cesium 131 (Cs-131) |
| Qualifier | Z None |
Procedure Overview
Brachytherapy for the endocrine system involves placing a radioactive source directly into or immediately next to a gland, such as the thyroid or an adrenal gland, rather than aiming radiation at it from outside the body. Because the source sits so close to the target tissue, it can deliver a concentrated dose to the tumor while limiting exposure to surrounding structures.
This approach is used less often for endocrine tumors than external beam therapy, but it may be chosen when a tumor is well localized and accessible, or when a patient has already received prior external radiation and cannot tolerate additional beam exposure to the area. The radioactive material can be left in place temporarily or permanently, depending on the type of source and the treatment plan developed by the radiation oncology team.
Patients typically undergo a minor procedure to place the source, followed by a defined period during which the radiation is active, after which temporary sources are removed.
Anatomy & Axis Detail
Parathyroid Glands
The parathyroid glands are tiny hormone-producing structures near the thyroid that regulate calcium homeostasis, and interstitial brachytherapy targeting them is rarely performed given their small size and close proximity to vital neck structures. When used, it is typically reserved for recurrent or residual parathyroid carcinoma after surgery, where a sealed radioactive source is placed directly into or near the tumor bed to deliver a concentrated dose that spares the trachea, esophagus, and recurrent laryngeal nerve running nearby. Because the glands can be difficult to visualize precisely and their number varies among individuals, preprocedural localization studies guide source placement, and documentation should note whether the target is a single remaining gland or a broader area of suspected residual disease.
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: Cesium 131 (Cs-131)
Cesium-131 is a permanent-seed brachytherapy isotope, similar in application to I-125 and Pd-103, implanted for prostate and other solid tumors, but distinguished by its notably shorter half-life of roughly 9.7 days. This compresses dose delivery into a shorter window than either I-125 or Pd-103, which can be clinically relevant for tumor kinetics and post-implant management.
Coding & Documentation
The operative note must document direct placement of a radioactive source in or adjacent to the endocrine gland, along with the specific gland treated, to support a code from this family. Coders should confirm whether the source was temporary or permanent, since this can affect qualifier selection and whether a separate removal procedure needs to be captured later. A common mistake is confusing brachytherapy with radioactive iodine ablation for thyroid disease, which is often administered orally or systemically rather than through direct implantation and may not be coded as a procedure in this section at all. Another pitfall is failing to code the placement device or applicator separately when the documentation calls for it under coding guidelines.