  The high dose gradients near the source characteristics of brachytherapy are
equivalent to nefarious effects if unnoticed errors take place during the
patient treatment. In vivo dosimetry is the only method to quantify the
delivered dose. Previous studies to this one, have characterized potential
detectors that can be used as in vivo dosimeter. Some of them have focused on
the source tracking topic in HDR brachytherapy. The aim of this study is to
perform 3D source position reconstruction by combining in vivo dosimetry
measurements from two independent detector systems. The first was based on
multiple (three) plastic scintillator detectors and the second on a single
inorganic crystal (CsI:Tl). By combining two detector responses, we enabled the
determination of the absolute source coordinates in 3D space. The method in
this study proposed can be extended to the combination of different systems.
