IMRT 2018

Investigate*the*dosimetric*impact

3 cases (liver metastases) 6 MV VMAT plans Two 180 arcs

Prescribed dose: 12 Gy / fraction Definition of interplay effects: Volume of ITV with dose difference > 5% between simulated and convolved dose distributions (V > 5% ) Parameters investigated: Amplitude – 5, 15, 25 mm peak-to-peak Period time – 3, 5, 7 s Dose rate – 600 and 1400 MU/min Plan modulation complexity – 3 plans with different MU/Gy

A. Edvardsson et al. 2016 Motion induced interplay effects for hypo-fractionated FFF VMAT treatment of liver tumours. Radiotherapy and Oncology, Vol. 119, S218