A lightweight, portable, interchangeable and effective overlay plate that will increase the efficiency of brachytherapy radiation treatment and reduce the duration of the radiation exposure during the radioactive seed insertion and positioning in brachytherapy. The overlay plate has a limited number of apertures specific to the treatment of a particular patient and is attached to the matrix used to position and guide the needles with the radioactive seeds. The apertures of the overlay plate may further be truncated-cone-shaped, with the narrow ends aligned with corresponding apertures in the matrix and the flared ends facing the user. The overlay plate minimizes the radiation exposure as much as reasonably possible because any amount of radiation exposure carries a risk to the exposed individual, and the overlay plate may also be manufactured from radiation-protective material to further minimize the radiation exposure.
