Microsoft Word - Scientific Program IGRT 2016 Madrid V3

Pelvic nodal dosing and bladder filling?

a relative bladder height change

18%

her exact test). Thirty-one kV-CBCTs

xis bony-to-fiducial translation

5 mm

and lower than the relative bladder height variations be-

tween groups with acceptable and suboptimal coverage

(

.001 and

.05, respectively). Only 2 kV-CBCTs, from

tive planning CTs (left) and kilovoltage cone-beam CTs (right) from 2 patients included in this study.

ical target volume (CTV

) 95%; bottom, V

100

CTV

65%. Cyan, CTV

; magenta, nodal planning target

isodose line; bright red, 95% isodose line; dark red, 90% isodose line. A color version of this figure is

2015

Pelvic nodal dosing: Implications fo SBRT

835

03/01/13

Kishan A, IJROBP 2015

Planning

CBCT of the day

Patient 1

Patient 2

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