ESTRO 2024 - Abstract Book

S4294

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

ESTRO 2024

Results:

Fifteen trans-continental institutions participated in the study (Europe=10, USA=4, Asia=1), representing both, proton (13) and carbon ion (2) facilities. Level of expertise in the clinical management of 4D cases was variable across institutes. Based on the general and specific questionnaires, a wide range of treated 4D indications were reported by facilities, including, e.g., lung, lymphoma, liver and esophagus. As presented in Figure 1, 4DCT is a standard procedure, with additional modalities, depending on the institutional guidelines, supporting the processing of target and OAR definition. However, as analyzed, differences in the binning approach (phase/amplitude) and in the number of reconstructed 4DCT phases (8/10) were observed.

Figure 2 presents the variety of reported motion mitigation solutions, whose use is dependent on the available tools, assessed motion extent and tumor location. The primary modality for planning among the institutions is averaged 4DCT, in combination at different institutes with deep inspiration breath-hold (DIBH), gated CT, 3DCT, mid-ventilation (MidV) image or combination of the average CT with selected breathing phases (e.g., T0, T50). For plan evaluation, most centers use either all or selected 4DCT breathing phases.