Intracavitary brachytherapy tandem and ovoid oncology treatment systems and methods are provided. One such system and method employs a multi-part tandem having a detachable distal section retained within a body cavity during and between radiation treatments. This can be for single-patient use and disposed of after completion of a multiple-dose radiation treatment session. Real time in vivo detection and monitoring and hytpertherapy features can be included. Tandem or ovoid colpostats can feature bendability to tailor the system to the specific body and patient being treated. Other systems and methods incorporate balloon devices that assist in spacing radiation doses away from chosen body sites. Balloon devices also can be provided for adjusting and maintaining separation spacing between two ovoid colpostats.