A frameless method for stereotactic radiotherapy.
A frameless method for stereotactic multiple arc radiotherapy (SMART) is described. Three short gold wires are implanted in the scalp approximately 100 mm apart. These are localized in a computed tomographic or angiographic study along with the target. Subsequently the gold markers are localized on beam films and the target position calculated using a computer program ISOLOC. This program provides the couch movements required to move the target to the isocentre and a micropositioner attached to the couch is used to make the adjustment. Beam films are repeated until the movements required are less than 1 mm in any direction. It is shown that the simple procedures of implanting the markers subcutaneously do not provide a stable reference system in about 25% of patients and the markers are now screwed into the cranium. The precision of the method is evaluated by phantom studies and measurements taken during several hundred treatments.
Jones
D
D
Northwest Medical Physics Center, Lynnwood, WA 98036-7306.
Christopherson
D A
DA
Washington
J T
JT
Hafermann
M D
MD
Rieke
J W
JW
Travaglini
J J
JJ
Vermeulen
S S
SS
D001927:Brain Diseases / Q000532:radiotherapy; D005069:Evaluation Studies as Topic; D006046:Gold; D006801:Humans; D008961:Models, Structural; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D013238:Stereotaxic Techniques
D006046:Gold