IMRT/IGRT Flashcards Preview

Dosimetry > IMRT/IGRT > Flashcards

Flashcards in IMRT/IGRT Deck (37):
1

how many MLC leaves are there

52-120 leaves

2

? dimensional data set req'd for planning

3D

3

in IMRT tx, fluence is

NONUNIFORM

4

in IMRT, MU in ? b/c fld blocked @ any time

more

5

mlc single focus is ? direction & ? ends

one & round

6

mlc double focus is ? edge

flat

7

vmat uses less/more mu compared to imrt

less

8

in inverse tx planning, the weights & intensities of beamlets are

adjusted

9

mlc INTRA leaf transmission is at what area

middle of leaf

10

mlc INTER leaf transmission is at what area

b/n 2 leaves

11

in forward tx planning a ? beam enters pt

UNIFORM

12

compensators are classes of ? system

imrt

13

mlc speed is > ? per second

2

14

dwell time is when leaves are ? in their configuration & beam is >

open; on

15

peacock system is the

collimator

16

crane is ? system

indexing

17

bat stands for

B-mode acquisition & targeting

18

MLC width is

0.5-2.0cm

19

in inverse tx planning, each beam ? as it enters pt

modified

20

in inverse tx planning, beam is ?

nonuniform

21

in inverse tx planning, coverage of tumor can be ?

predetermined

22

mlc INTRA leaf transmission is ?%

0.8-1.5%

23

mlc INTER leaf transmission is ?%

1.1-2.5%

24

wedges are classes of ? systems

imrt

25

examples of transmission blocks are

-dynamic jaws
-moving bars
-mlc
-tomo collimators
-scanned elementary beams

26

transmission blocks are the only 5 that allow

dynamic intensity modulation

27

do leaves have same velocity in dynamic step & shoot?

diff velocity

28

? delivers 1 fld at each gan angle; typically tx 3-5 arcs

IMAT

29

crane system has what accuracy

0.1-0.2mm

30

crane system reduces inhomogeneity to +/- ? %

3%

31

mimic is ? leaves per bank

20

32

? treats 1 or 2 slices tx @ a time

mimic

33

MLC is made of ? cm thick tungsten

8

34

in helical tomo, mlc is while table moves

reconfigured

35

with imrt, it is possible to achieve dose distrib comparable to ?

x-ray/gamma knife

36

imrt can compete with ? therapy

p+

37

imrt is/isn't effective tx superficial disease

is