Physics Bucharest 2017
Reason 1) before 1951 many beams to reduce skin dose
1895: discovery X-rays 1913: 140 kV, Coolidge: vacuum tube, heated kathode
1921: 200 kV 1925: 300 kV 1951: first cobalt treatment unit 1952: first clinical linear accelerator (Increase Energy → reduce skin dose) orthovoltage
100 120
Dose
0 20 40 60 80
> 1913 > 1951 > 1952
early days
Depth [cm]
0
5
10
15
20
25
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