Author(s)

Mark Geurts

Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, USA.

The capability of the TrueBeam treatment system to deliver step and shoot IMRT plans at low dose rates was evaluated. Beam characteristics during low dose rates (5 to 100 MU/min) were evaluated for consistency using a planar ion chamber array. MU constancy, linearity, and beam profile symmetry were all found to be equivalent within 0.5%. The response of the Scandi Dos Delta 4 system was also evaluated at low dose rates of using static open beams compared to ion chamber measurements, and step and shoot IMRT plans comparing 5 - 20 MU/min and 100 MU/min dose rates, with a maximum observed absolute dose difference of 0.8% and equivalence margin of 0.2%. The Gamma Index and measurement reproducibility were also found to be equivalent.

PRDR, Low Dose Rate, Delta 4, TrueBeam

Geurts, M. (2017) TrueBeam Low Dose Rate Investigation for Pulsed Reduced Dose Rate IMRT. International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, 6, 139-149. doi: 10.4236/ijmpcero.2017.62013.