1620-1621 / 3581
ESTRO IG and Adaptive
Course Parikh 25.10.2016
CTV, PTV margins for APBI:
Brachytherapy (Mammosite, SAVI):
Cavity + 1 cm = CTV = PTV
EBRT:
Cavity + 1-1.5 cm = CTV.
CTV + 1 cm = PTV
PTV = Cavity + 2-2.5 cm
Larger PTV margins needed due to:
Setup uncertainty
Intra-fraction motion
We sought to evaluate MR-IGRT for delivery of APBI given easy
localization of cavity on MRI (setup) and ability to monitor intra-
fraction motion.
Background
Cavity
Preferred
Alternative
CTV=Br PTV
EBRT PTV
Courtesy of Maria Thomas, MD, PhD
MRG-RT: Moderate Experience - Breast