Fractionated radiotherapy of small inoperable lesions of the brain using a non-invasive stereotactic frame.
Arteriovenous malformations (AVMs) and benign or low grade, small malignant tumors can be treated by stereotactic radiotherapy in a single fraction. This report describes a technique for stereotactic treatment of small lesions using conventional, fractionated, photon beam irradiation. The Laitinen's stereoadapter, non-invasive head frame was used. This device was tested for accuracy by serial mountings and found to be accurate within 1 mm. The accuracy of the dose delivered was within 2%. Adaptation of this device to the linear accelerator required the design of secondary circular collimators which decreased the penumbra from 3-4 mm to 2-3 mm. The dose fall off outside the target volume is steep enough when using two non-coplanar arcs (90 to 10% within 1 cm). Thermoluminescent dosimetry (TLD) in a humanoid phantom showed good correlation with the calculated dose. This system permits delivery of fractionated radiation therapy to small volumes, easily and accurately, under stereotactic conditions.
Delannes
M
M
Department of Radiotherapy, Hopital Purpan, Toulouse, France.
Daly
N J
NJ
Bonnet
J
J
Sabatier
J
J
Tremoulet
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000532:radiotherapy*; D002648:Child; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D010315:Particle Accelerators; D011879:Radiotherapy Dosage; D013238:Stereotaxic Techniques