Fig. 2

Difference between two cycles of chemotherapy and baseline was assessed for ¹⁸F-FAZA T/Bg (a) and ¹⁸F-FDG SUV (b) in the all primary tumor voxels of seven (¹⁸F-FAZA) and six (¹⁸F-FDG) patients, respectively. a The vertical line in figure (a) denotes the hypoxic cutoff of 1.4 T/Bg. Areas above 1.4 T/Bg are considered hypoxic. A decrease in ¹⁸F-FAZA activity can be seen as a result of treatment, yet this is not so clear compared to ¹⁸F-FDG. The decrease in ¹⁸F-FAZA activity is, however, most pronounced in the most hypoxic areas. b Per patient, different cutoff values are seen, due to the use of the 41 % adoptive threshold technique in selecting tumor areas. A clear decrease in ¹⁸F-FDG activity in almost all tumor voxels as a result of treatment. Although the decrease is clear overall, the decrease is most pronounced in areas with initially the highest ¹⁸F-FDG uptake