# The proton therapy research beamline at the Christie NHS foundation trust

## TL;DR

This paper describes a new proton therapy research facility in the UK that enables detailed biological and dosimetric studies to improve cancer treatment.

## Contribution

The paper introduces a unique UK-based proton therapy research beamline with high-throughput irradiation workflows and accurate dosimetry for radiobiological studies.

## Key findings

- The Manchester proton therapy research facility provides a clinically relevant platform for in vitro and in vivo experiments.
- A Monte Carlo beam model was developed to predict and validate complex measurements with high accuracy.
- High-throughput irradiation workflows and environmental control reduce experimental uncertainties in radiobiological research.

## Abstract

Proton therapy is a relatively new modality for cancer treatment and has several open research questions, particularly in the biological realm. Due to large infrastructure costs the modality is reserved for specialist treatment, limiting the patient outcome dataset. This requires supplementation with fundamental research through in vitro and in vivo systems. Similarly, the safety and potential benefits of new treatments, such as FLASH, should be demonstrated in lab environments prior to clinical translation. Greater access to clinically relevant research platforms is required. This work presents the capabilities of the Manchester proton therapy research facility for experimentalists’ assessment to meet their research goals. Details of the research beamline geometry are presented, along with workflows for in vitro sample irradiation within an automated sample handling environmental chamber. Absolute dose and dose depth of the proton research beamline was measured. The dose calibration across a range of energies and dose rates is presented and fits are mathematically described. Methods to convert measured, or planned, dose to sample dose are presented including for biological studies investigating end of proton range effects. Elements of the beam optics, impacting on spot size and therefore field homogeneity, were measured for sample irradiation and beam model development. A Monte Carlo beam model was established to predict physically difficult measurements and is compared to measurements throughout. Achievable dose rates for FLASH are presented alongside absolute dosimetric accuracy. There was a focus on radiobiological research in establishing the beamline. Special care was taken to develop high-throughput repeatable in vitro irradiation workflows, with an adjacent radiobiological lab for immediate processing. This will lead to a reduction in experimental uncertainties seen in the literature with demonstrated accurate dosimetry, tight environmental control, and a high degree of versatility. The infrastructure presented in this work is a unique facility in the UK.