Brain 17 Vienna

Technical Procedure

Junction lines are moved 0.5-1.0 cm every 8-12 Gy

to avoid overdosing or underdosing segments of the cord

Procedure: 1. shortening the inferior margin of the lateral cranial fields 2. Symmetrically lengthening the superior and inferior margins of the posterior spine field 3. Shortening the cranail margin of the caudal spinal field 4. The caudal spinal field remains unchanged

moving junction

SSD 100 cm

SSD 100 cm

tumour

rotation of collimator according to divergence angle of upper spinal field

isocentre

Spinal canal

SSD : source to skin distance