IGRT 2016 Madrid

Pelvic nodal dosing and bladder filling? Pelvic nodal dosing: Implications fo SBRT 835

! 2015

Inadequate nodal coverage if : ? SI shift on the prostate >5mm ? Or variation of bladder height >18% 3 SOLUTIONS: 1. Enforcing strict bladder filling 2. Larger nodal PTV margins 3. Daily online replan or library of plans

Planning

CBCT of the day

tive planning CTs (left) and kilovoltage cone-beam CTs (right) from 2 patients included in this study. ical target volume (CTV N ) 95%; bottom, V 100 CTV N 65%. Cyan, CTV N ; magenta, nodal planning target isodose line; bright red, 95% isodose line; dark red, 90% isodose line. A color version of this figure is djournal.org . Patient 1 Patient 2

and lower than the relative bladder height variations be- tween groups with acceptable and suboptimal coverage ( P < .001 and P < .05, respectively). Only 2 kV-CBCTs, from Kishan A, IJROBP 2015

a relative bladder height change < 18% her exact test). Thirty-one kV-CBCTs xis bony-to-fiducial translation < 5 mm 03/01/13