ESTRO 2024 - Abstract Book

S4069

Physics - Inter-fraction motion management and offline adaptive radiotherapy

ESTRO 2024

Results:

A total of 100 CBCT images were delivered and registered with the planning CT scans. The data was represented in Table 1 and Figure 1. There was no statistical difference in the doses encompassed CTV (CTV V 25Gy ), comparing among bone (translation) correction (98.91%, 98.11-99.72), bone (translation and rotation) correction (98.97%, 98.18-99.77), or bone/soft tissue correction (98.68%, 98.65-99.71), p=0.378. Bladder showed a trend of higher V 25Gy with bone/soft tissue correction (12.70%, 9.56-15.84) compared to bone (translation) correction (10.43%, 6.77-14.10) and bone (translation and rotation) correction (10.51%, 6.82-14.19), p=0.005. Bowel V 25Gy were higher with bone/soft tissue correction (69.48 cc, 53.06-85.90) compared to bone (translation/rotation) correction (51.55 cc, 43.26-59.85) and bone (translation) correction (48.27 cc, 38.88-57.66), p=0.006.

Table1: Dosimetric data of 100 CBCT images

Mean Value

NonRo vs Ro

NonRo vs Soft

Ro vs Soft

p value

bone (translation):

bone

Protocol

Plan

bone/soft tissue: Soft

(translation and

NonRo

rotation): Ro

CTV V 23.75Gy (%)

100%

99.84% (99.65 100.00)

99.77% (99.42-100.00)

99.40% (99.86 100.00)

0.257

1.000

0.534

0.766

V 25Gy (%)

98.91% (98.11-99.72) 10.00% (5.84-14.14) 22.33% (17.07-27.60) 10.43% (6.77-14.10)

98.97% (98.18-99.77) 9.94% (5.76-14.12) 22.38% (17.15-27.61) 10.51% (6.82-14.19)

98.68% (98.65-99.71) 9.13% (5.34-12.91) 25.85% (21.43-30.26) 12.70% (9.56-15.84)

> 99%

99.92%

0.378

0.006

0.974

0.114

V 26.25Gy (%)

9.88%

< 10%

0.027

1.000

0.068

0.110

Bladder V 22.2Gy (%)

< 40%

26.33%

0.002

1.000

0.006

0.005

V 25Gy (%)

< 15%

11.50%

0.005

1.000

0.015

0.014

V 27.8Gy (%)

< 0%

0.00%

0.00%

0.00%

0.00%

1487.23 (1365.41 1609.05)

1485.84 (1369.61 1602.07)

1536.54 (1425.88 1647.20)

AUC (%V.Gy)

1574.85

0.013

1.000

0.062

0.034

Bowel V 19.5Gy (%)

< 180cc

153.92cc

170.92cc (149.01 192.43)

171.63cc (149.20 194.06)

189.42cc (157.31 221.53)

0.053

1.000

0.155

0.167