ESTRO 2024 - Abstract Book

S4586

Physics - Optimisation, algorithms and applications for ion beam treatment planning

ESTR0 2024

The results indicated that the coplanar arc at a couch angle of 0° consistently remained the longest within the iterative process, along with the smaller couch angles at ± 10°. The number of arcs in each plan did not have a significant impact on the plan quality metrics; D95% (p > 0.9), D99% (p > 0.9), Paddick’s CI (p > 0.9), dose gradient (p > 0.9) and maximum dose from PTV (p > 0.7).

The study found that non-coplanar arcs with smaller couch angles (+/- 10°) had no significant improvement or degradation for SABR spine patients when compared to coplanar planning techniques. This was highlighted by the lack of statistically significant differences for the plan quality metrics; D95% (p > 0.1), D99% (p > 0.3) of the PTV, the gradient of the line dose profile from the target to the isocentre (p > 0.5), Paddick’s conformity index (p > 0.3) and maximum dose 0.2cm from the PTV (p > 0.3).

Conclusion: