Episcleral plaques are commonly used for the treatment of ocular rumours su
ch as choroidal melanoma. Treatment planning involves the assignment of see
ds to slots on the plaque to achieve a desired dose rate distribution. Seed
assignment is rather straightforward if seeds are ordered on demand. Howev
er, the assignment task becomes tedious and laborious if the seeds have to
be chosen from an existing stock of seeds with different activities. To dar
e, this task has usually been performed by a human planner through trial an
d error. An algorithm has been developed to automate the task of seed assig
nment using a mixed-integer programming method. We also explore ways to sim
plify the problem such that the method becomes practical in most facilities
. We have tested the method on three randomly chosen clinical cases from ou
r past records, to show that the algorithm could yield solutions within a s
horter time frame and with less deviation from the desired dose rate distri
butions, as compared with the solutions from a human counterpart.