Abstract #3072

MRI & Biopsy Performance in Delineating Recurrent Tumor Boundaries After Radiotherapy for Prostate Cancer

Cynthia Menard^1,2, Douglas Iupati¹, Jenny Lee¹, Anna Simeonov¹, Jessy Abed¹, Julia Publicover¹, Peter Chung¹, Andrew Bayley¹, Charles Catton¹, Michael Milosevic¹, Robert Bristow¹, Gerard Morton³, Padraig Warde¹, Kristy Brock¹, Masoom Haider³

¹Princess Margaret Hospital, Toronto, ON, Canada; ²Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada; ³Odette Cancer Center

We evaluated the performance of MRI (plus/minus guided biopsy) in delineating tumor boundaries for focal salvage therapy of prostate cancer recurrence after external beam radiotherapy. Twenty-three patients were enrolled and received an integrated multiparametric diagnostic and interventional biopsy procedure. MRI alone was not sufficiently accurate to define boundaries for tumor-targeted salvage even with addition of an uncertainty margin. MRI-guided biopsy improved both detection and delineation accuracy for recurrent tumor regions, and changed salvage therapy planning in the majority of patients.