ESTRO 2024 - Abstract Book

S4157

Physics - Intra-fraction motion management and real-time adaptive radiotherapy

ESTRO 2024

Figure 2. Motion tracking structure selection: (a) spinal cord only; (b) spinal cord and a signal vertebra; (c) Three vertebral bodies including spinal cord.

Conclusion:

From the pilot study, real-time motion tracking in the MR-guided spine SBRT seems feasible. Further analysis with an increased sample size will help to identify the safe and optimal tolerance for clinical motion management system and evaluate final tracking results and the necessity and frequency of baseline shifts over time.

Keywords: Spine SBRT, MR-guided, motion tracking

References:

Keiper TD, Tai A, Li XA. Feasibility of real-time motion tracking using cine MRI during MR-guided radiation therapy for abdominal targets. Med Phys. 2020 Aug;47(8):3554-3566

Jassar H, Tai A, Li XA. Real-time motion monitoring using orthogonal cine MRI during MR-guided adaptive radiation therapy for abdominal tumors on 1.5T MR-Linac. Med Phys. 2023 May;50(5):3103-3116.

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Proffered Paper

Real-time adaptive radiation therapy for multiple lung targets: a proof-of-concept study

Emily A Hewson 1 , Lars Mejnertsen 1 , Jeremy T Booth 2,3 , Paul J Keall 1

1 Image X Institute, University of Sydney, Sydney, Australia. 2 Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, Australia. 3 School of Physics, University of Sydney, Sydney, Australia

Purpose/Objective:

Accurate radiation therapy for lung cancer patients with multiple lesions is challenging due to the large, independent motion of targets during treatment [1]. Real-time adaptive methods to account for multiple lung targets do not exist and currently motion can only be compensated using large margins which result in increased healthy tissue doses and cannot guarantee target coverage. Recent studies have also suggested that these patients could greatly benefit from higher escalated doses [2], furthering the need for an accurate motion adaptive treatment strategy. To address this issue, a multi-target multileaf collimator (MLC) tracking method was developed to demonstrate a world-first method that adapts to the motion of multiple lung targets independently in real time and was investigated in silico for lung cancer stereotactic ablative radiation therapy (SABR) treatment.