Proton therapy plays a crucial role in treating specific types of tumors. Compared with conventional photon therapy, it can significantly reduce radiation to healthy tissues, thereby lowering the risk of undesirable side effects. However, there is still room for improvement, especially when tumors are located very close to critical organs.
To ensure safe treatment, radiation plans include margins that account for uncertainties such as small patient movements or anatomical changes. These safety margins guarantee that the entire tumor receives the prescribed dose, but they also increase the radiation exposure of healthy tissue. Reducing these margins could therefore further minimize side effects and improve patients’ quality of life—provided that we can verify that treatment delivery remains accurate.
This in vivo range verification assesses the precision with which radiation is delivered into the patient by determining the depth at which the proton beam stops, i.e., the proton range. Because this range lies within the body, it cannot be measured directly. Instead, the secondary radiation produced during treatment, such as positron-emitting activity, can be visualized using positron emission tomography (PET) imaging techniques.
Current imaging systems, however, only provide information after treatment, limiting their usefulness for immediate verification. This thesis of Brian Zapien Campos focuses on developing a real-time method that enables continuous monitoring during patient irradiation. This approach represents a major step toward safer, more precise proton therapy and offers the potential to reduce treatment-related side effects.
