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 suitable for retaining within a body cavity such as the uterus, both during radiation treatment and during recovery time between radiation treatments. This distal portion can be intended for single-patient use and be disposed of after completion of a radiation treatment session having multiple radiation dose treatment times. One or both of real time in vivo detection and monitoring and hypertherapy features can be included. One or more of the system tandem or ovoid colpostats feature bendability to tailor the system to the specific body and patient being treated. The method includes having a tandem distal section inserted into a body cavity such as a uterus and remaining within the body cavity in between treatment times. Other systems and methods incorporate balloon devices that assist in spacing radiation doses away from body sites at which radiation treatment is not intended. Balloon devices also can be provided for adjusting and maintaining separation spacing between two ovoid colpostats while intracavitary.