Patients were randomized to four different treatment arms: SFX (2
Gy / fraction / day to 70
Gy in 35 fractions over seven weeks), HFX (1.2
Gy / fraction, twice daily, to 81.6
Gy over seven weeks), AFX - S (1.6
Gy / fraction, twice daily, to 67.2
Gy over six weeks, with a two - week break after 38.4
Gy) and AFX - C (
total dose of 72
Gy delivered over six weeks in 1.8
Gy daily fractions and additional 1.5
Gy boost field in the afternoon during the last 12 days of treatment).
The
total radiation delivered, 0.5 gray (
Gy), was high relative to environmental levels (from sources such as naturally occurring radon in rock), but significantly lower than equivalent human doses experienced in CAT - scans or cancer therapy.