Towards an optimal clinical protocol for the treatment of moving targets with pencil beam scanned proton therapy

At the University Medical Center Groningen (UMCG) Proton Therapy Center (GPTC), a novel and advantageous form of radiotherapy for the treatment of cancer is available. This treatment technique, referred as proton therapy, uses charged particles (protons) to irradiate, and consequently, damage the tumour. Due to the physical properties of protons, proton therapy allows to successfully kill the tumour, while sparing the adjacent healthy tissue from any damaging radiation. The tumours within liver, lung, and oesophageal cancer patients move due to the patients’ respiration. These moving tumours are surrounded by organs (heart, lung, spinal cord, and oesophagus), which need to be spared from radiation. This is why proton therapy is particularly valuable for these patients. However, the interference of the movement of these tumours with the highly precise proton therapy machine, brings a challenge for the execution of their treatments at the GPTC, and other proton centres. The work performed throughout this thesis focuses on achieving optimal and safe proton treatments for moving tumours. To complete this, we performed comprehensive and representative analysis with clinical patient data and proton machine specific information of our department. The tools developed and the results obtained contributed to the start of the treatment of moving tumours at the GPTC, and therefore we believe they will play an important role for the proton therapy community in general. We aim to extend our gained experience to all proton centres worldwide, so that moving tumours can take advantage of the clinical benefits expected from proton therapy.