2017_SBRT_Course Book

IGRT/Frameless: rotational correction

• 40 patients, 66 Brain metastases • Treatment with 6-DOF robotic couch correction based on ET/NB IGRT • Retrospective simulation of 4-DOF by manipulation of CT-dataset in TPS, omitting rotational correction • Paddick Conformity Index reduces from 0.68 to 0.59 (6-DOF versus 4-DOF correction)

6-DOF

4-DOF

TV PI

TV PI TV

PI ×

• Loss of 5% in prescription isodose coverage (80%).

Gevaert et al. Int J Radiat Oncol Biol Phys 2012 SBRT 2017 - D. Verellen

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