In medicine, there is a clear trend towards individualized therapies, for cancer and other diseases. Individualized treatment planning for cancer, particularly in radiotherapy and light therapies, is a complex optimization problem. As analytical inverse planning solutions do not exist for light therapies, a large number of light delivery configurations must be evaluated to find one that best conforms to the clinical target (e.g., a tumour). An integral part of this optimization is the accurate computation of light dose, ideally using Monte Carlo (MC) simulations for realistic, 3-D modelling....