L 23: HDR Brachy Flashcards
(16 cards)
1
Q
AAPM TG 56
Daily checks after Brachy
A
- AV systems
- radiation indicator lights
- Interlocks
- Source positioning accuracy
2
Q
At the time of source exchange
A
- Source strength measurements
- Printing of new decay tablets
During source exchange, only activity of the source is changed all the other parameters remain same like dose rate constant, geometry factor, radial dose function, anisotropy factor. activity~air kerma
3
Q
eye plaque
A
- eye diagram
- selection of eye plaque size/height
- treatment plan
- prescription dose: 8000-10000 cGy
- plaque preparation
4
Q
LDR
A
0.5-2 cGy/min
5
Q
HDR
A
> 20cGy/min
6
Q
leakage
A
<1mR/h at a distance of 10cm
7
Q
Electron brachy
A
- XOFT
- contura
8
Q
Lutathera / Lu 177
A
Beta decay
Energy - 497 KeV
9
Q
Ra 223 - Xofigo
A
Therapheutic dose is alpha emitter
10
Q
TYpical activity for an I192 source when first exchanged into HDR afterloader
A
10.0 Ci
11
Q
Brachy problem
A
12
Q
HDR , AAPM TG-43
A
formula can be used to calculate the dose on either MRI or CT scan.
13
Q
Post prostate seed implant
A
30 days (heal from procedure) post implant CT scan shuld be taken
14
Q
Brachy problem
A
15
Q
Annual QA for Us guided brachy
A
- Needle template alignment
- Axial and lateral resolution
- grayscale visibility
16
Q
Nuclear medicine, amount present after 1 hour of ingestion depends on
A
- 1/2 life of the radioisotope
- rate of organ uptake
- rate of organ clearance
