# Dynamic proton arc treatment planning study for oesophageal cancer

## TL;DR

This study compares a new proton therapy technique called Particle Arc Therapy (PAT) with traditional methods for treating oesophageal cancer, finding that PAT better protects nearby organs but takes longer to deliver.

## Contribution

The study introduces and evaluates a dynamic proton arc therapy approach for oesophageal cancer treatment.

## Key findings

- PAT reduced doses to organs at risk like the spinal canal, lungs, and heart.
- PAT plans maintained robustness despite uncertainties in motion, setup, and range.
- Delivery time for PAT was twice as long as conventional proton therapy.

## Abstract

Particle Arc Therapy (PAT) is considered a promising technique to improve conformity and reduce toxicities. Robustly optimized PAT plans were evaluated versus Intensity Modulated Proton Therapy (IMPT) for oesophageal cancer in 17 patients. Impact of motion, setup and range uncertainties on target coverage, plan quality and Organs At Risk (OAR) doses were assessed. PAT (two 80°–200°arcs) reduced OAR doses (spinal canal D0.05cm3: 5.12 Gy (12.8%), lungs and heart Dmean: 0.39 Gy (8.8%) and 0.83 Gy (10.5%)) while maintaining robustness. Similar toxicities were observed, but delivery time was doubled for PAT, indicating that further development is needed.

•Dynamic arc improved organ sparing.•Delivery time was doubled versus conventional protons.

Dynamic arc improved organ sparing.

Delivery time was doubled versus conventional protons.