C.8.8.27 Beam Limiting Device Position Macro

Table C.8.8.27-1 specifies the attributes that specify the Beam Limiting Device Sequence.

Table C.8.8.27-1BEAM LIMITING DEVICE POSITION MACRO ATTRIBUTES

Attribute Name Tag Type Description
Beam Limiting Device Position Sequence (300A,011A) 1C Introduces sequence of beam limiting device (collimator) jaw or leaf (element) positions. One or more items shall be included in this sequence. Required if Ion Beam Limiting Device Sequence (300A,03A4) or Beam Limiting Device Leaf Pairs Sequence (3008,00A0) is included in this SOP instance and for first item of Ion Control Point Sequence, or if Beam Limiting Device changes during Beam.
>RT Beam Limiting Device Type (300A,00B8) 1 Type of beam limiting device (collimator). The value of this attribute shall correspond to RT Beam Limiting Device Type (300A,00B8) defined in an item of Ion Beam Limiting Device Sequence (300A,03A4). Enumerated Values: X = symmetric jaw pair in IEC X direction Y = symmetric jaw pair in IEC Y direction ASYMX = asymmetric jaw pair in IEC X direction ASYMY = asymmetric pair in IEC Y direction MLCX = multileaf (multi-element) jaw pair in IEC X direction MLCY = multileaf (multi-element) jaw pair in IEC Y direction
>Leaf/Jaw Positions (300A,011C) 1 Positions of beam limiting device (collimator) leaf (element) or jaw pairs (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), e.g. X-axis for MLCX, Y-axis for MLCY. Contains 2N values, where N is the Number of Leaf/Jaw Pairs (300A,00BC) in Ion Beam Limiting Device Sequence (300A,03A4). Values shall be listed in IEC leaf (element) subscript order 101, 102, ... 1N, 201, 202, ... 2N. See section C.8.8.25.3.