ESTRO 2024 - Abstract Book

S4711

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

ESTR0 2024

Figure 2: Dose statistics of the 1,625 treatment course simulations for plans robustly optimized with 3mm and 5mm setup uncertainty, with individual patient excess risk estimates.

Conclusion:

It is possible to reduce the robustness margin settings from 5mm to 3mm for breast IMPT treatment while maintaining target coverage, and simultaneously achieving a significant reduction in OAR dose and the risk for secondary tumours. However, it is important to pay attention to the lymph nodes, as they are most affected by the margin reduction and therefore further work on differential setup errors relative to the CTV should be performed.

Keywords: IMPT, margin reduction, breast cancer

References:

1. Darby SC, Ewertz M, McGale P, Bennet AM, Blom-Goldman U, Brønnum D, Correa C, Cutter D, Gagliardi G, Gigante B, Jensen MB, Nisbet A, Peto R, Rahimi K, Taylor C, Hall P. Risk of ischemic heart disease in women after radiotherapy for breast cancer. N Engl J Med 2013; 14;368(11):987-98.

2. Taylor C, Correa C, Duane FK, Aznar MC, Anderson SJ, Bergh J, Dodwell D, Ewertz M, Gray R, Jagsi R, Pierce L, Pritchard KI, Swain S, Wang Z, Wang Y, Whelan T, Peto R, McGale P; Early Breast Cancer Trialists' Collaborative Group.Estimating