OC-0135 GEC-ESTRO / ACROP recommendations for Quality Assurance of Ultrasound in Brachytherapy. (May 2021) - Siebert, F.; Kirisits, C.; Paulsen Hellebust, T.; Baltas, D.; Verhaegen, F.; Camps, S.; Pieters, B.; Kovács, G.; Thomadsen, B.