ESTRO 2024 - Abstract Book

S3397

Physics - Detectors, dose measurement and phantoms

ESTRO 2024

Conclusion:

We present a general method for mapping the SR around the Liac HWL. Care must be taken in the choice of the detector to avoid underestimating the SR. 2 cm of RW3 is sufficient to stop scattered low penetration SR. The system is safe to be used in unshielded ORs in our reference setup. Additional measurements using clinically relevant linac orientations are planned.

Keywords: radioprotection, IORT

3108

Digital Poster

Physical dose validation of dynamic treatment for Gamma Knife radiosurgery

Benjamin Z Tham 1 , Dionne M Aleman 1 , Robert K Heaton 2 , Håkan Nordström 3 , Catherine Coolens 2

1 University of Toronto, Mechanical & Industrial Engineering, Toronto, Canada. 2 Princess Margaret Cancer Centre, Radiation Oncology, Toronto, Canada. 3 Elekta Instrument AB, Elekta AB, Stockholm, Sweden

Purpose/Objective:

Dynamic treatment in Gamma Knife (GK) radiosurgery systems delivers radiation continuously with couch movement, and has the potential to give faster treatment times and improved dose conformity and homogeneity. Existing GK dynamic treatment studies have focused only on computational simulations, and this study aims validate them with physical experimental measurements. The experiments aim to (1) address assumptions made with computational studies, such as the validity of treating a continuous path as discretised points, (2) investigate uncertainties in translating computed plans to actual dynamic treatment, and (3) determine ideal treatment planning parameters, such as interval distance for the discretisation of movement paths, collimator change limitations, and minimum isocentre treatment times.