ESTRO 2024 - Abstract Book

S5485

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

ESTRO 2024

Fig. 2: translations and rotations of the post-CBCT for the three investigated groups: without a wedge (NoW), with the old wedge (OW) and with the new wedge (NW).

Conclusion:

In both groups with wedges, 2/12 (17%) patients had an intrafraction motion exceeding the tolerance of >1 mm and/or >1 degree. It can be concluded that the GTV-PTV margin cannot be reduced to 1 mm for patients laying on wedges.

Keywords: IGRT, Radiosurgery, Margin

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Poster Discussion

Verification accuracy comparison of Transperineal ultrasound & CBCT,in preparation for Prostate SABR

Harley Stephens

university hospitals bristol, radiotherapy, Bristol, United Kingdom

Purpose/Objective:

The aim of the study was to compare the use of Clarity trans-perineal ultrasound (TPUS), against the ‘Gold standard’ of Cone beam computed tomography (CBCT) with fiducials, for verification of patients receiving radical radiotherapy to the prostate. There is a clinical advantage to evaluate the value of using ultrasound alone, due to its non-ionising properties.