Brachytherapy

Question 0

Therapeutically relevant distance & energy

Answer 0

Distance= 3 to 20 mm
Only photons (x- or gamma rays) with 
Energies >15 keV

Question 1

Guide for brachytherapy dosimetry

Answer 1

Task Group 43

Question 2

Factors that influence the single-source dose distribution (photon-emitting sources):

Answer 2

1. Distance (inverse-square law)
2. Absorption & scattering in the source core & encapsulation
3. Photon attenuation
4. Scattering in the surrounding medium

Question 3

Effects of encapsulation on a brachytherapy source

Answer 3

1. Prevents radioactive leakage
2. Absorbs non-penetrating radiation (beta, alpha rays, low-energy photons)
3. Decreases surface dose

Question 4

Isotropic point source

Answer 4

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