Data acquisition for PET in On-beam Hadrontherapy

The invention is part of the techniques for monitoring the path of the charged particles in the patient during an oncological hadrontherapy treatment. In Hadrontherapy, beams of light ions are accelerated in such a way as to hit and damage the tumour tissue inside the patient while sparing the surrounding healthy tissue. The invention concerns an original technique for improving image quality thanks to a new method of indirect synchronization of the acquisition system with the accelerator.

How does it work?

The invention consists of a PET (Positron Emission Tomography) system capable of monitoring the range of an hadrontherapy beam during irradiation. The system consists of two detector heads arranged approximately 50 cm apart, orthogonally to the beam direction. The detectors are based on LYSO scintillating blocks and SiPM photosensors, read by an array of ASICs, which in turn are managed by an FPGA. The acquired data is processed in real time in the FPGA itself and transmitted to a PC for further processing. A dedicated algorithm allows real-time filtering of the acquired events while minimizing data losses due to digital transmission limits.

Applications

• Study of fast, low-energy hadronic processes to improve the predictive power of treatment planning systems;
• Monitoring of treatment outcome in patients;
• Real-time monitoring and control of charged particle range in patients.

Advantages

• Significant noise reduction in monitoring images produced in the first moments of treatment;
• Possible reduction of the safety margins normally adopted in hadrontherapy (up to one cm around the tumour target) and therefore reduction of toxicity on healthy tissues;
• Less invasive monitoring operation than current systems due to high acquisition efficiency.