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Protec9ve!shielding!
Collimator!channels!
Leksell
®!
Coordinate!
Frame!
Pa9ent!!
posi9oning!system
!
Radia9on!sources!
Isocenter/!
Target!in!the!brain!
Frame-based Stereotactic Radiosurgery
Positioning Accuracy
Accuracy!and!stability!of!posi9oning!in!radiosurgery:!!
long!–term!results!of!the!Gamma!Knife!system.!
!
!
!
!
!
!
!
!
!!!!!Heck!B!et!al!
Med!Phys!2007!Apr;!34(4):!1487J95!
Graf2Chromic2films2
densitometric!measurements!
!
!
!X:!J!0.014+/J!0.09mm!
!
!
!Y:!!!!0.013+/J!0.09mm!
!
!
!Z:!J!0.002+/J!0.06mm!
!
!
All!measured!data!were!within!a!sphere!of!!
0.2mm
!radius!
!
2
MRI>based2target2defini0on2
!
!
!X:!0.06+/J0.09mm!
!
!
!Y:!0.04+/J0.09mm!