TriangleFOR PATIENTS · SOURCE READING
Interstitial brachytherapy
Source: Radiation for Breast Cancer, National Cancer Institute.
Source updated: Not stated in this source · Captured 2026-09-09.
Selected source text with whitespace normalised. This Triangle page is not an NCI PDQ summary. Independent clinical review is pending.
NCI patient treatment article for this disease Exact source article; not a clinically reviewed indication or current-standard recommendation.
In interstitial brachytherapy, several small tubes, called catheters, are inserted into the tissue where the breast cancer was and stitched in place. This is most often done 1 to 2 weeks after surgery. A radiation source, such as radioactive pellets or seeds, is temporarily placed into the catheters during each treatment session. Treatments usually last about 20 minutes. Two kinds of sources, high-dose implants and low-dose implants, can be used:
High-dose implants: If you receive high-dose implants, the radiation is delivered once or twice a day for about 5 days. You will be able to leave the hospital after each treatment, and you will not remain radioactive after. It is safe to be around others, including babies and children.
Low-dose implants: If you receive low-dose implants, treatment can be delivered over several hours to days. The radiation source stays in place and is slowly delivered to the tissue around the catheters. You will stay in the hospital throughout treatment to avoid exposing others to radiation. The radiation source and catheters are removed when treatment is complete. Then you can go home.
Preserved source evidence · Independent clinical review pending · Not medical advice