Physics Bucharest 2017

Exact match of field edges using ‘half’ beams

focus

Breast

junction plane through isocenter

‘half’ beam

Simple geometry, complex dosimetry

 couch always at 0   AP-field: only use upper half of collimator  tangential fields: only use lower half of collimator  in junction plane exact match, defined by sides of leaves (independent of leaf calibrations)

central axis

cranial edge