Fig. 2.

Subtraction images (A) and associated signal enhancement threshold vs volume curves (B) from representative patients for each of the three groups. The slices are approximately through the center of the tumour. The pink outline represents the skin/air interface. The single fraction images show clear evidence of an increase in the signal enhancement volume local to the tumour following SABR, and this is not seen in the 30 Gy/3 fraction patient. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)