ESTRO course Dose Modelling and Verification 2017

400-401 / 1245

Other image possibilities
MRI images?
 MRI superior soft tissue contrast
 Lower intraobserver variation
 Smaller margins
 Bulk density assignment?
 Bone must be delineated on the scans
 Doses not as accurate as could be
 DRR’s difficult
 Atlas-based electron density mapping method
 MRI atlas built up from number of patients
 Corresponding CT data sets
 Patient MRI mapped to atlas, same vectors applied to CT Atlas
 PseudoCT and planning CT dose differences 95%
<2%/2mm.
 Full examination of uncertainties needed
 How similar is anatomy of patients?
Dowling IJROBP 83 (2012). Prostate