Brachytherapy for Prostate Cancer 2017

CT T1+T2 CT+T2

Impact of interobserver variability on D90

Ref_D90 MeanObs_D90

SD

interobserver variability with respect to reference (1SD)

ref

Pat ient 1

Contouring large interobserver variability for D90 for all techniques Seeds ▪ CT: small interobserver spread for D90 ▪ slightly larger for technique (b), using T1 for seeds Fusion ▪ T1 + T2 : interobserver variability relatively small, but patient dependent ▪ CT + T2 : large interobserver variability

Patient 2

Patient 3

CT T1+T2 CT+T2