Effetto dei movimenti che avvengono durante la singola frazione di trattamento e tra diverse frazioni utilizzando la tecnica proton pencil beam scanning per la cura dei tumori all'esofago

This project focus the attention on the oesophageal cancer, in particular the main purpose is to enhance the treatment accuracy. The first goal of this study is to analyze how intra and interfraction motion influence the oesophageal cancer treatment made with proton pencil beam scanning. In particular, available 4DCT scans allow to focus the attention on the breathing cycle. To do that several treatment planning systems, which differ on field configuration and robust optimization, are considered and tested. A spot-adapted scheme considering interplay effect is implemented and tested. It is interesting to observe if and how the spot-adapted scheme changes the dose delivered to the tumour target volumes and to significant organs at risk compared with the classic proton pencil beam scanning technique. The goal is to identify the field configurations and the coverage strategies less influenced by interplay effect and to understand if robust optimization improves the treatment. To do that, 4D accumulated dose and 4D dynamic dose are calculated and compared.