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Breast
Complex target
Issues to consider for matching
Superior edge of tangential field to inf edge of nodal field.
Solutions
Angulation
By inferior angulation of the tangential fields
Calculated angles for couch, gantry and collimator to keep match plane at
junction
Half beam block technique (single isocentre)
Blocking the supraclav field’s inferior half, eliminating its divergence
inferiorly
?Leave a gap
Risk of under dosing