A device for radiation treatment of proliferative tissue surrounding a cavity in an animal body includes at least a first inflatable chamber having a wall for placement in the cavity, a supportive probe having an elongated body with a distal end connected with the first inflatable chamber and a proximal end remaining outside the cavity, a device for inflating and deflating the first chamber, and a radiation delivering device for placing at least one energy emitting source within the cavity for performing said radiation treatment. It is possible to temporarily position a solid energy emitting source in a reproducible manner at different locations within the inflated chamber, such that subsequent identical radiation treatment sessions can be performed, whereas the comfort of the patient is maxim and an out hospitalization treatment is possible.