Brachytherapy

Question 1

use of radioactive sources in close proximity to target area for radiotherapy

Answer 1

brachytherapy

Question 2

other names for brachytherapy

Answer 2

internal radiation therapy
sealed therapy
radium therapy
curie therapy
plesiotherapy
endocurie therapy

Question 3

Advantage of brachytherapy

Answer 3

improved localized dose to target

Question 4

Disadvantage of brachytherapy

Answer 4

only good for well-localized tumors, small lesions, labor intensive

Question 5

Contraindications of brachy

Answer 5

1. if tumor not clearly delineated
2. active infection
3. if evidence of bone involvement

Question 6

earliest form of radiotherapy 19th century

Answer 6

radium

Question 7

ideal brachytherapy source

Answer 7

pure gamma emitter
medium gamma energy
high specific activity
stable daughter product
long half live (temporary implants)
medium half life (permanent implants)

Question 8

1. 226 Ra
   Half life:
   Proton E.:
   HVL:

Answer 8

226 - Radium
1600 years
0.047-2.45 MeV
8.0 mm Hg

Question 9

2. 222 Rn
   Half life:
   Proton E.:
   HVL:

Answer 9

222 - Radon
3.83 yrs
0.047-2.45 MeV
8.0 mm Hg

Question 10

3. 60 Co
   Half life:
   Proton E.:
   HVL:

Answer 10

60- Cobalt
5,26 yrs
1.17, 1.33 MeV
11.0 mmHg

Question 11

4. 137- Ce
   Half life:
   Proton E.:
   HVL:

Answer 11

137- Cesium
30.0 yrs
0.662 MeV
5.5 mmHg

Question 12

5. 192 -Ir
   Half life:
   Proton E.:
   HVL:

Answer 12

192 - Iridium
74.2 yrs
0.36-1.06 MeV
2.5 mmHg

Question 13

6. 198 - Au
   Half life:
   Proton E.:
   HVL:

Answer 13

198- Gold
2.7 yrs
0.412 MeV
2.5 mmHg

Question 14

7. 125 - I
   Half life:
   Proton E.:
   HVL:

Answer 14

125 - Iodine
60.2 years
0.028 MeV
0.025 mmHg

Question 15

8. 103-Pd
   Half life:
   Proton E.:
   HVL:

Answer 15

103 -Paladium
17.0 yrs
0.21 MeV
0.008 mmHg

Question 16

first radioisotope used clinically in 1903

Answer 16

Radium

Question 17

Reasons why radon and radium is not used anymore

Answer 17

a. wide energy spectrum - high dose close to source (difficult shielding)
b. Radon - daughter product is a noble gas (contamination risk)
c. long half life means disposal is difficult

Question 18

main substitute for radium
used in gynecological applications

Answer 18

137 Ce

Question 19

measure estimate radioactive decay

Answer 19

decay correction

Question 20

decay correction for 137 Cs [..]
must be replaced every [..]

Answer 20

every 6 mos
10-15 yrs

Question 21

most important source for HDR (high dose rate) applications

Answer 21

192 Ir

Question 22

decay correction for 192 Ir [..]
must be replaced every [..]

Answer 22

for each treatment
3-4 mos

Question 23

radioisotope with very low energy-shielding is easy and easily absorbed
mostly used in the form of seeds

Answer 23

125 I

Question 24

replacement for I 125
permanent implant
dose rate 2.5 larger than 125 I

Answer 24

103 Pd

Question 25

energy for 103 Pd

Answer 25

22 kV

Question 26

energy for 103 Pd

Answer 26

22 keV

Question 27

permanent implant short enough to let activity decay in patient energy [..]

Answer 27

Gold 198 412 keV

Question 28

wire, low dose rate radioisotope interstitial implant

Answer 28

Iridium 192

Question 29

[source shapes and forms] balls of approx 3mm diameters

Answer 29

pellets

Question 30

[source shapes and forms] small cylinders about 1mm diam and 4mm length

Answer 30

seeds

Question 31

[source shapes and forms] b/w 15 and 45 mm active length

Answer 31

needles

Question 32

[source shapes and forms] about 14 mm length, used for gynecological implants

Answer 32

tubes

Question 33

[source shapes and forms] shaped as it is, approx. 60mm active length

Answer 33

hairpin

Question 34

[source shapes and forms] any length, customized in the hospital inactive ends may be added

Answer 34

wire

Question 35

[source shapes and forms] high activity miniature cylinder sources approx 1mm diam, 10 mm length

Answer 35

HDR Sources

Question 36

small containers for activity usually 125 I, 103 Pd or 198 Au for permanent implant

Answer 36

seeds

Question 37

implants in operating theater, directly introduced to ROI usually 192 Ir for temporary implants

Answer 37

needles and hairpins

Question 38

radioisotope used for LDR interstitial implants cutting manual technique

Answer 38

192 Ir wire

Question 39

[applicators] treatm. of superficial lesions with radioactive sources in close contact with skin

Answer 39

Surface Moulds

Question 40

introduction of radioactivity using an applicator placed in a body cavity

Answer 40

intracavitary implants

Question 41

intracavitary implant usually used in:

Answer 41

gynecological bronchus esophagus rectum

Question 42

most common application for cervix cancer either monotherapy or addition to EBT

Answer 42

gynecological implants

Question 43

often used in palliative to open air ways HDR brachytherapy most often single catheter

Answer 43

bronchus implants

Question 44

implants of needles of flexible catheters directly in the target area requires surgery - often major

Answer 44

interstitial implants

Question 45

interstitial implants are commonly used in:

Answer 45

breast head and neck sarcomas

Question 46

typically a boost often utilizes templates to improve source positioning

Answer 46

breast implants

Question 47

[implant technique] pt. discharged with implant in place

Answer 47

permanent implants

Question 48

[implant technique] implant removed before pt. is discharged from hospital

Answer 48

temporary implants

Question 49

treats breast ca from within breast in 5 days with fewr side fx than standard 6 or 7 wks uses special balloon catheter in lumpectomy cavity and inflated with saline solution

Answer 49

Mammosite

Question 50

other name for mammosite

Answer 50

balloon catheter radiation

Question 51

Adv. of mammosite

Answer 51

completed in 5-7 days surgical scar but no skin thickening or burns v. small portion and healthy tissue unaffected

Question 52

Disadv. of mammosite

Answer 52

avoid showers for a week saline filled balloon feels odd infections can occur

Question 53

used in operating theatre useful for incomplete removal of ca

Answer 53

intraoperative brachytherapy