ESTRO 2024 - Abstract Book

S5487

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

ESTRO 2024

Average distance between CBCT and TPUS was 0.13±2.8 mm

Pearson R- 0.916

Ant/Post

Difference between set up error measurements as a function of the mean using Bland Altman analysis were -0.41, 0.36 mm

TPUS agreed with CBCT 91.7% of the time within 3mm, and 98.3% of the time between 5mm

Median absolute difference between TPUS and CBCT was 1.3mm

Average distance between CBCT and TPUS was -0.2±3.9 mm

Pearson R- 0.849

Conclusion:

Clarity TPUS has the benefit of no additional dose and intra-fractional monitoring after initial verification. Results show a very good correlation between the different modalities and that the modalities has the potential to be used interchangeably when prostate SABR is introduced. Inter-observer variability is to be considered, and further research with a larger population would be of benefit.

Keywords: Prostate, SABR, IGRT

References:

1) A.C. Tree, V.S. Khoo, N.J. van As, et al.Is biochemical relapse-free survival after profoundly hypofractionated radiotherapy consistent with current radiobiological models? Clin Oncol, 26 (2014), pp. 216-229. Is Biochemical Relapse-free Survival After Profoundly Hypofractionated Radiotherapy Consistent with Current Radiobiological Models? - ScienceDirect

2) Fontanarosa, D., et al., Review of ultrasound image guidance in external beam radiotherapy: I. Treatment planning and inter-fraction motion management. Phys Med Biol, 2015. 60(3): p. R77-114.

3) O'Shea, T., et al., Review of ultrasound image guidance in external beam radiotherapy part II: intra-fraction motion management and novel applications. Phys Med Biol, 2016. 61(8): p. R90-137.

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