%0 Journal Article
%A Saito, Nami
%A Schmitt, Daniela
%A Bangert, Mark
%T Correlation between intrafractional motion and dosimetric changes for prostate IMRT: Comparison of different adaptive strategies.
%J Journal of applied clinical medical physics
%V 19
%N 4
%@ 1526-9914
%C Reston, Va.
%I ACMP
%M DKFZ-2018-01234
%P 87 - 97
%D 2018
%X To retrospectively analyze and estimate the dosimetric benefit of online and offline motion mitigation strategies for prostate IMRT.Intrafractional motion data of 21 prostate patients receiving intensity-modulated radiotherapy was acquired with an electromagnetic tracking system. Target trajectories of 734 fractions were analyzed per delivered multileaf-collimator segment in five motion metrics: three-dimensional displacement, distance from beam axis (DistToBeam), and three orthogonal components. Time-resolved dose calculations have been performed by shifting the target according to the sampled motion for the following scenarios: without adaptation, online-repositioning with a minimum threshold of 3 mm, and an offline approach using a modified field order applying horizontal before vertical beams. Change of D95 (targets) or V65 (organs at risk) relative to the static case, that is, ΔD95 or ΔV65, was extracted per fraction in percent. Correlation coefficients (CC) between the motion metrics and the dose metrics were extracted. Mean of patient-wise CC was used to evaluate the correlation of motion metric and dosimetric changes. Mean and standard deviation of the patient-wise correlation slopes (in 
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:29862644
%2 pmc:PMC6036361
%R 10.1002/acm2.12359
%U https://inrepo02.dkfz.de/record/136796