Internal Radiation (Brachytherapy) In some types of cancer, the tumors are more difficult to treat using external radiation. Cancer treatment at the Baystate Regional Cancer Program includes internal beam radiation therapy, or brachytherapy, as a more effective way to target these tumors. This involves placing the radiation source inside the body, next to or in the tumor. Our radiation oncology experts offer the most advanced internal beam radiation options, including: High-Dose Rate (HDR) Implants If you are receiving high-dose rate implants, you can expect: Right before your treatment, an applicator will be put in place to help administer the radiation. The radiation source will be placed internally for 10 to 20 minutes at a time, and then removed. You will need to return for treatment once a week for two to five weeks. Your individual schedule will depend on your type of cancer. Permanent Interstitial Implants If you are receiving permanent interstitial implants, you can expect: You will receive anesthesia to keep you pain free while the radiation seeds are implanted. Once the radiation seeds are in place, they will stay in your body. The amount of radiation emitted from the seeds will decrease each day, eventually ending. You should limit your time around other people when the radiation is first put in place, especially children and pregnant women.