IMRT/IGRT Flashcards
how many MLC leaves are there
52-120 leaves
? dimensional data set req’d for planning
3D
in IMRT tx, fluence is
NONUNIFORM
in IMRT, MU in ? b/c fld blocked @ any time
more
mlc single focus is ? direction & ? ends
one & round
mlc double focus is ? edge
flat
vmat uses less/more mu compared to imrt
less
in inverse tx planning, the weights & intensities of beamlets are
adjusted
mlc INTRA leaf transmission is at what area
middle of leaf
mlc INTER leaf transmission is at what area
b/n 2 leaves
in forward tx planning a ? beam enters pt
UNIFORM
compensators are classes of ? system
imrt
mlc speed is > ? per second
2
dwell time is when leaves are ? in their configuration & beam is >
open; on
peacock system is the
collimator
crane is ? system
indexing
bat stands for
B-mode acquisition & targeting
MLC width is
0.5-2.0cm
in inverse tx planning, each beam ? as it enters pt
modified
in inverse tx planning, beam is ?
nonuniform
in inverse tx planning, coverage of tumor can be ?
predetermined
mlc INTRA leaf transmission is ?%
0.8-1.5%
mlc INTER leaf transmission is ?%
1.1-2.5%
wedges are classes of ? systems
imrt
examples of transmission blocks are
- dynamic jaws
- moving bars
- mlc
- tomo collimators
- scanned elementary beams
transmission blocks are the only 5 that allow
dynamic intensity modulation
do leaves have same velocity in dynamic step & shoot?
diff velocity
? delivers 1 fld at each gan angle; typically tx 3-5 arcs
IMAT
crane system has what accuracy
0.1-0.2mm
crane system reduces inhomogeneity to +/- ? %
3%
mimic is ? leaves per bank
20
? treats 1 or 2 slices tx @ a time
mimic
MLC is made of ? cm thick tungsten
8
in helical tomo, mlc is while table moves
reconfigured
with imrt, it is possible to achieve dose distrib comparable to ?
x-ray/gamma knife
imrt can compete with ? therapy
p+
imrt is/isn’t effective tx superficial disease
is
