Surface membrane based bladder registration for evaluation of accumulated dose during brachytherapy in cervical cancer

A new optimisation strategy for surface mesh registration is proposed based on energy minimisation of an elastic surface membrane. The energy term is evaluated in three-dimensional space, optimisation however is performed while constraining the moving surface to a parametrised spherical space of the fixed surface. Optional landmark based matches can be included in the suggested iterative solver. The technique is demonstrated for bladder registration in brachytherapy treatment evaluation of cervical cancer. It holds promise to better estimate the accumulated but unintentional dose delivered to organs at risk.