Leksell Gamma Knife coordinate setting slippage: how often, how much?
OBJECTIVE
The aim of this study was to determine the incidence and magnitude of coordinate setting slippage during gamma knife surgery (GKS).


METHODS
Thirty-six consecutive patients undergoing GKS with a Leksell unit between June and December 2000 had their coordinates (right and left x-, y-, and z-coordinates; 1548 coordinates; 258 isocenters) and gamma angles checked after the delivery of treatment to each isocenter to determine whether the coordinate settings had slipped and, if so, which settings and the magnitude of the slippage.


CONCLUSIONS
Coordinate setting slippage during GKS with a Leksell unit does occur but is rare. The magnitude of such slippage is typically within the error of the stereotactic system and coordinate reading. The authors noted that coordinate setting slippage is significantly correlated with patient weight.
Division of Radiation Oncology and Department of Neurologic Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA. robert@mayo.edu
Robert L
RL
Foote
Bruce E
BE
Pollock
Michael J
MJ
Link
Yolanda I
YI
Garces
Robert W
RW
Kline
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000601:surgery*; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects* / Q000295:instrumentation*; D012189:Retrospective Studies; D016474:Weight-Bearing