Where is a brachytherapy usually done? At a hospital?

Hospital. Brachytherapy is a form of radiation therapy to treat prostate cancer. It is a painful procedure and requires anesthesia. It also usually requires fluoroscopy (x-ray) which is available in the operating room.
Seeds. Brachytherapy is usually performed under anesthesia, so that would be either at a hospital or outpatient surgery center.