Presentation on theme: "What is the appropriate margin for focal therapy of prostate cancer when using MRI/MRSI for treatment planning? Proposed secondary study for ACRIN 6659."— Presentation transcript:
1What is the appropriate margin for focal therapy of prostate cancer when using MRI/MRSI for treatment planning?Proposed secondary study for ACRIN 6659 dataFergus Coakley MD, Professor of Radiology and Urology,Chief, Abdominal Imaging, University of California San Francisco
2ObjectiveDetermine the appropriate margin for focal therapy of prostate cancer when planned from MRI/MRSI
3BackgroundIncreasing interest in focal therapy as “middle way” for prostate cancer treatmentActive surveillance – minimalistDefinitive treatment (RRP or RT) – high morbidityThree requirements for focal therapy:Clinical selection – no consensusRadiological selection – MRI criteria on next slideAdequate margin – purpose of this proposal
4UCSF selection study88 patients with MRI/MRSI before RRP and with detailed tumor mapsMRI/MRSI reviewed by two independent readersDominant treatable foci = largest lesion & > 0.5ccResults:ALL visible lesions on T2 with ≥0.54 cm3 of concordant MRSI abnormality (n = 27 and 25 for reader 1 and 2, respectively) were correctly identified dominant treatable tumor foci
5Proposal (two steps) Apply UCSF criteria to ACRIN database T2 visible & ≥0.54 cm3 concordant MRSITwo readers (remote or travel to ACRIN HQ?)Anticipate small number will meet criteria (<10?)Co-register digital pathology with T2Pick largest/best T2 image and “best match” pathology slideMorph gland outline on pathology to T2 (allows margin measurement using MRI calipers)Measure maximum margin (per quadrant and separate capsular from non-capsular?)
6“Best match” T2 MRI and pathology slice Example“Best match” T2 MRI and pathology slice
9Measure margins – maximum capsular and non-capsular plus by quadrant? ExampleMeasure margins – maximum capsular and non-capsular plus by quadrant?
10AnalysisPresumably will be essentially descriptive – what margin would have encompassed all the tumors?Issues for discussion:Explore additional selection criteria?More than two reads?Can readings be done remotely?Who will fuse images and measure margins?Funding level? Travel and/or time?