Treatment Plan Robustness Under iPDT Source Position Uncertainty

Clinical iPDT operations cannot guarantee perfect dose delivery due to unavoidable uncertainties in both the power emitted precise position of a source. We use software tools to simulate and analyze the impact of uncertainties under angular variated insertions. Evaluate angular variation of each light source in 8 directions. Simulations are run on Colin27 brain models with nine virtual brain tumours constructed from GBM images from the cancer imaging archive. Analyze the volume of 100% dose for grey, white matters and tumour using a random combination of deviated directions for each light source for each model. The final result is on average less desirable than the nominal due to uncertainty in positions. The next steps for this work is to summarize a pattern for each tumour model and to find a way of improving the PDT-SPACE optimization algorithm that is more robust to position uncertainty.