ESTRO 2022 - Abstract Book

S303

Abstract book

ESTRO 2022

SP-0343 Robust treatment planning in particle therapy: Clinical implementation and potential pitfalls

E. Korevaar 1

1 UMCG, Radiotherapy, Groningen, The Netherlands

Abstract Text In photon treatment planning target volumes (PTVs) are used to make sure that the clinical target volume (CTV) receives adequate dose despite treatment uncertainties. The underlying static dose cloud approximation (the assumption that the dose distribution is invariant to errors) is problematic in intensity modulated proton treatments where range errors should be taken into account as well. A solution is robust planning, i.e., explicitly taking into account uncertainties in the robust optimization and robustness evaluation of treatment plans, in so called treatment scenarios. Although robust planning is conceptually straightforward, it introduces difficulties, e.g. in the scenario selection and evaluation of corresponding scenario dose distributions. The purpose of this talk is to give background information and provide practical choices to help the transition from PTV based planning to robust treatment planning. Important aspects are limitations of the method, assessment of criteria by benchmarking against a PTV method, and to include the whole radiation oncology team in the process. Furthermore, pitfalls and common misconceptions are discussed.

Teaching lecture: Essentials for risk management of a radiation oncology department

SP-0344 Essentials for risk management of a radiation oncology department

E. Ford

USA

Abstract not available

Teaching lecture: Less is more: The increasing use of hypofractionation in routine clinical practice and its impact on patient care

SP-0345 How should IGRT practices be revised to reflect delivery of large doses per fraction?

J. Ter-Minasjan

Estonia Abstract not available

SP-0346 How may shorter fractionation schedules affect patient care?

A. Stewart-Lord 1

1 London South Bank University, Institute of Health and Social Care, London, United Kingdom

Abstract Text Hypofractionation has shown to be beneficial in the management of a wide range of cancers1,2 including other advantages such as cost savings3. Trials over the last decade4,5,6 have demonstrated the advantages of hypofractionation compared with a standard radiotherapy regimen3. Covid-19 significantly impacted the way in which cancer patients7 are managed and even though the use of hypofractionation is well established in some cancer types; the application thereof during the pandemic has been widely expanded to minimise treatment time8. Even though the treatment outcomes have been well defined, there is limited evidence to suggest changes in patient care. Some oncology centres advocated for a reduced contact time between patient and staff9. Hypofractionation in an ageing population is particularly advantageous in allowing people to receive treatment in a shorter time demonstrating treatment outcomes similar to younger age groups10 however; greater consideration should be given to performance status and comorbidities associated with these treatment outcomes11. Fractionation schedules which allow delivery in less fractions, can be highly effective with limited treatment-related toxicity. Studies have shown that the late consequences of radiotherapy in these patient groups are seldom an issue even with larger fraction s12. However more recent studies suggest that a reduction in treatment time should not be the only reason for selecting this approach. Moderate hypofractionation should therefore be considered for those patient who are younger and who might experience long terms effects13. More studies are now investigating the tolerability of ultra-hypofractionated radiotherapy in an attempt to improve the therapeutic gain, suggesting that these approaches are well-tolerated and showed no statistical difference in toxicity14.

Hypofractionation in radiotherapy may be a good alternative to conventional fractionation however patience care remains paramount in the management of all toxicities related the radiotherapy delivery. There is no evidence to