ESTRO 2024 - Abstract Book

S4147

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

ESTRO 2024

Results:

Table 1 presents the mean and standard deviation of the positional mismatch for the AP, LR and SI direction for all patients. Since SI motion was present on both the sagittal and coronal planes, we reported on this motion separately by using the notations SI sag and SI cor respectively.

direction

mismatch

AP

-0.11 mm ± 0.26 mm

LR

-0.01 mm ± 0.06 mm

SI sag

0.08 mm ± 0.33 mm

SI cor

-0.26 mm ± 0.43 mm

Table 1: Positional mismatches per direction (mean ± std)

Overall, the mismatch between the two algorithms is close to zero for all motion directions. Figure 1 presents an example of intrafraction motion tracking using CMM and elastix.

The number of drift corrections corresponding to the CMM- and elastix-based motion signals using 1 mm and 2 mm decision thresholds are presented on Table 2. An overall good agreement between the two algorithms for both decision thresholds can be observed.