Fig. 3.

(a) VMAT plan for extremity MLS (GTV in red and PTV in blue). 95% isodose line (in thick green) encompasses the PTV on CT simulation image. (b) CBCT after 15 fractions shows significant tumor shrinkage (white arrow); original GTV and PTV contours are outside body anatomy. (c) Tumor response resulted in changes in target shape and volume, consequently 95% isodose line encroaches to normal nearby tissues, thus requiring adaptive radiation. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)