ESTRO 2024 - Abstract Book

S4227

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

ESTRO 2024

intrafractional dose distribution, dose constraint was met in all sessions with “on couch” and Table 3 shows the dose volume index with “pre”. V45Gy < 1cm 3 was not met in 4 sessions of 2 patients for stomach, and those of duodenum was not met in 5 sessions of 3 patients. However, comparing to our previous report taking interfractional motion into consideration, the degree of deviation was minor (1).

Table 2. The Simpson similarity coefficient between “on couch” and “pre”

Organ

Margin (mm)

Median Simpson similarity coefficient (range)

Stomach

10

1 (0.96-1)

7 5 5 3

0.98 (0.90-1) 0.97 (0.83-1)

Duodenum

0.87 (0.73-0.94) 0.82 (0.63-0.90)

Conclusion:

Although there was a certain intrafractional motion, oART is promising for reducing PRV margins.