ESTRO 2024 - Abstract Book

S5555

RTT - Patient care, preparation, immobilisation and IGRT verification protocols

ESTRO 2024

treatment sessions were used for the trial purpose. Couch shifts deviations were registered prospectively in the X (lateral),Y (longitudinal) and Z (vertical) directions for translations (automatic and manual corrections). The deviations in rotations (pitch, yaw and roll) were also registered. Comparisons were based on a Friedman's test on repeated measures. The RTTs’ satisfaction was assessed through dedicated surveys provided by Orfit industries, and evaluated through 3 domains: aesthetics, positioning reproducibility, and ergonomics. Answers to questions were scored using a Likert Scale ranging from 1 (strongly disagree) to 5 (strongly agree) and finally expressed in a percentage score.

Results:

Seventy-five women (60 ± 14 years old) treated in our department for breast cancer between 2017 and 2022 were included in the study: 37 in the MammoRX arm and 38 in the AIO Solution arm. Only 2 benefitted from lymph node irradiation in addition to the breast and both were randomised in the AIO Solution arm. Altogether, 1125 CBCTs were analysed in this trial.

As reported in Table 1, no statistically significant difference was observed in interfraction deviations for translations (automatic and manual) or for rotations.

Seven RTTs involved in the study answered to the survey. Their individual scores are reported in the radar plots illustrated in Figure 2. The general appreciation rates were similar between devices, with a score of 3,46 (69.1%) of satisfaction rate for the MammoRX vs 3,46 (69.3%) for the AIO Solution. The ergonomics was the only category were a difference could be observed in the surveys, with 2,98 (59.6%) satisfaction rate for the MammoRX vs 3,75 (75,0%) for the AIO Solution. This is of importance since the ergonomics appears to be the more relevant criteria for users besides the reproducibility rate, which was assessed by the trial [1].

Table 1 : Results of interfraction deviations in both arms (MammoRX and AIO Solution arms) depending on automatic and manual translations (in cm), and automatic rotations (in degrees).

Deviations

Direction

MammoRX 0.45 ± 3.30 -0.83 ± 4.60 -1.38 ± 4.00 0.99 ± 0.83 0.64 ± 0.98 0.63 ± 0.77 0.81 ± 3.29 -0.23 ± 4.70 -1.00 ± 4.00

AIO

p-value

Automatic Translation (in cm)

X Y Z

0.26 ± 3.24 0.49 ± 4.85 -0.95 ± 4.57 0.96 ± 0.99 0.76 ± 1.02 0.26 ± 3.30 0.89 ± 4.73 -0.81 ± 4.25 0.87 ± 0.8

0.45 0.40 0.22 0.20 0.23 0.49 0.08 0.96 0.14

Automatic Rotation (in degree)

Pitch

Yaw

Roll

Manual Translation (in cm)

X Y Z

Figure 1 : MammoRX and AIO Solution immobilisation devices proposed by Orfit industries and used in this trial for breast cancer patients treatments.