Radiation diagnosis devices, systems and methods are in general catheter form and include at least one expandable component that provides at least one diagnosis function and assists in placement of at least one radiation detector at a desired diagnosis location within an existing body cavity or at a percutaneous site or surgically-created site. Data collected by the detector that is positioned as determined by the medical professional allows the medical professional to monitor radiation levels, either residual from a prior radiation treatment, during a brachytherapy treatment at the catheter insertion site or in adjoining site, or during externally administered radiation.
