Advanced Tech and Imaging Gammaknife and Cyberknife

Question 1

What were the key components of original gamma knives?

Answer 1

• 201 cobalt sources
• hemispherical arrangement
• collimator around frame attached to patient
• single or multiple isocentres treated

Question 2

What did newer specs (gammaknife) include?

Answer 2

• fewer cobalt sources
• a cylindrical configuration with five concentric rings
• no primary and secondary collimators
• integrated unit with collimator settings

Question 3

What is the problem with using ‘infinity’ beams?

Answer 3

• Nodes, path sets, isocentres vs non-isocentre modes, beam directions, modulation and motion tracking
• have to comprimise optimised plan vs delivery time
• intensity modulation is only through multiple beams delivered at unique points in the target volume
• During irradiation, movement through uses optimised path