ESTRO 2024 - Abstract Book

S5624

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

ESTRO 2024

The population systematic error (∑) was expressed as the SD of the patient systematic errors, while the population random error (σ) was the root mean square of the average of all individual SDs.

Patient experience was self-reported using a Likert scale of 1-5 where 5=no anxiety whilst in the treatment position and 1=very anxious whilst in the treatment position.

Results:

16 thoracic patients underwent radical external beam radiotherapy with daily CBCT imaging between August 2023 and October 2023. 8 were treated with five-point immobilisation and 8 with four-point immobilisation. A total of 1920 displacement values were collected for analysis. The mean, systematic and random set up errors in all six dimensions are summarised in figure 2.

The four-point shells were less prone to systematic translational errors compared the five-point shells. There was no difference in randomised translations set up errors.

Five-point shells had less randomised rotational set up errors and there was little difference in terms of systematic rotational error.

Patients self-reported their experience of radiotherapy treatment where 5=no anxiety and 1=very anxious; those patients undergoing radiotherapy using a five-point shell had a mean score of 2.7, whilst those using a four-point shell demonstrated an improved mean score of 3.8.

Conclusion: