ESTRO 2024 - Abstract Book

S3531

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

Conclusion:

Co-planar partial-arc FFF VMAT technique produced equivalent target coverage, improved efficiency, better normal tissue sparing, and shorter delivery time compared to non-coplanar IMRT technique. Shorter delivery time also assists in the reduction of patient motion associated with breath hold. VMAT technique with FFF delivery is a suitable replacement for IMRT in APBI.

Keywords: APBI, VMAT, dose evaluation

1053

Digital Poster

Evaluation of treatment planning technique on metallic implant in Radixact® using Monte Carlo Method

Fu Ki Yeung, Chi Wai Cheung, Tin Lok Chiu, Siu Ki Yu

Hong Kong Sanatorium & Hospital, Medical Physics Department, Hong Kong, Hong Kong

Purpose/Objective:

There are patients with hip, dental, spine implants etc receiving radiotherapy treatment every day. Patients with metallic implants are common in nowadays radiotherapy treatment. Physicists may be consulted to decide from the following few treatment planning techniques, standard CT with override CT number of metallic implants by a commercially known density (NoExOv), standard CT with actual CT number (NoExNoOv) or extended CT with actual CT number (ExNoOv). Contouring of the implant is a challenging task due to CT dilution effect of metals. The metals show shape distortion and radial volume growth. This posts a controversial issue whether accepting the uncertainty of metal contouring or the measured CT number of metal. Currently, Siemens CT machines provide an option for extended CT scale so to avoid HU saturation upon dense metals. Some previous research focused on the comparison of these treatment planning techniques in AAA algorithm from Eclipse™ TPS (Varian Medical Systems, Inc).