Abstract: A system for supporting a brachytherapy treatment includes a medical imaging system and a processing unit. The medical imaging system includes a SPECT unit and/or a CT unit. The processing unit is configured to receive a planning dataset, and determine a brachytherapy treatment plan based on the planning dataset. The treatment plan includes a planned dose distribution for a radiation source. The medical imaging system is configured to acquire a supervision dataset that includes an intra-procedural representation of the radiation source that, in an operating state of the system, has been positioned at a treatment site within a treatment region via a medical guide instrument. The processing unit is configured to register the supervision dataset and the planning dataset, determine an actual dose distribution based on the supervision dataset, and provide supervision information based on a comparison between the planned and actual dose distribution.