We developed a discrete tomography method for prostate implant reconstructions using only a limited number of X-ray projection images A 3D voxel volume is reconstructed by back-projection, using distance maps generated from the projection images The true seed locations are extracted from the voxel volume while false positive seeds are eliminated using a novel optimal geometry coverage model The attractive feature of our method is that it does not require exact seed segmentation of the X-ray images, it yields near 100% correct reconstruction from only six images with an average reconstruction accuracy of 0 86 mm (std = 0 46mm)