Meningiomas are the most common primary brain tumors in adults. They originate from the dura tissue, which is the closest layer of tissue to the skull, and often develop in the parasagittal region of the brain. Non-specific tumor treatments, including state of the art microsurgical techniques, cannot remove tumor tissue that has infiltrated major blood vessels in the parasagittal region. Tumor specific treatments are needed to eliminate cancerous tissue without damaging essential underlying tissues. Photodynamic Therapy (PDT) is a tumor specific treatment where oxygen molecules (3O2) react with a photosensitizer drug (S0) in the presence of high energy light to produce oxygen free radicals (1O2) that trigger apoptotic pathways. PDT is limited by the effective penetration depth of 3O2 in tissue. The penetration depth of 3O2 in tissue can be increased by maximizing the amount of oxygen carried in the blood and by accelerating the rate at which blood flows within the tissue. In Hyperbaric Oxygen Therapy (HBOT) patients are placed in a high pressure and oxygen environment which leads to massive increases in blood oxygen concentration. In Magnetic Heat Therapy (MHT), magnetic nanoparticles generate heat which is dispersed by increased blood flow within the tissue.
The Finite Element Method (FEM) is used to simulate the treatment of a parasagittal meningioma and breakaway layer of cancerous cells within healthy tissue. The effects of PDT/MHT and PDT on patients in a hyperbaric chamber were simulated. Negligible differences were found between treatments as HBOT is sufficient to saturate the tissue with oxygen. Our model corroborates existing literature suggesting that PDT can be used to specifically treat a tumor. A lethal dosage of oxygen free radicals accumulated in both the primary and breakaway cancerous layers following 100 seconds of PDT. The surrounding healthy tissue was left unharmed throughout the procedure. The results suggest that the [S0] remains approximately constant throughout PDT. Future models may treat the [S0] as a constant to greatly reducing the amount of coupling between equations. This allows future models to account for factors including reduced blood flow within tissue that is damaged by PDT. Although there is considerable research on PDT/MHT and PDT/HBOT, no existing literature investigates the potential of PDT/MHT/HBOT for treating brain tumors. The novelty of our project and the ethics involved with studying cancer treatment in human patients reduces the availability of data that can be used for validation of models. Thus, experiments should be conducted to improve the quality of our validation and support or refute the trends identified in our results.