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RT of Stomach: volumes
•
GTV:
Gross disease (if visualized on PET and/or CT) and pathologically
enlarged lymph nodes
•
CTV
: GTV + stomach volume outlined from gastroesophageal junction to
beyond the duodenal bulb; the whole wall is included (perigastric nodes are
encompassed, if visible).
•
ITV
is determined by 4-D CT or by fluoroscopy to track variation of stomach
position during respiration. An additional margin of at least 1-2 cm may be added
to the CTV to accommodate stomach movement or internal volume changes.
•
PTV
is influenced by set-up variation; in the abdomen 1 cm over final ITV is
advised.
•
OAR
volumes for consideration in planning include: kidneys, liver, heart. lungs,
bowel, cord.