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Imaging in Modern RT for Lymphoma
Old RT
Modern RT
Large volume + high dose
Smaller
volume
+ lower
dose
Conventional Sim
CT
Sim
2D planning: Anatomical borders related to
bony landmarks
3D
outlining
Simple calculation
Computerised
calculation – 3D dosimetry
No correction for tissue inhomogeneity
Correction for tissue
inhomogeneity
AP / PA
Possibility of
complex
field arrangement if
appropriate
No OAR doses
OAR
doses and constraints
Blocks
MLC
s
Sometimes: only 1 field treated daily or
patients turned round between fields
All
fields treated daily
Pt in same position ±
immobilisation
Crude verification of delivery (beam film)
Verification with
Image-guidance
(IGRT)