16 Cervix Carcinoma

Cervix Cancer 309

Fig 14.4: GTV at diagnosis in definitive radiotherapy of limited disease (stage IIB with proximal parametrial extension): Drawing (1) and MRI study (2) (T2-weighted). The tumour extends into the left parametrium in the dorsal direction. Dimensions of the GTV (white arrows) are 4 cm in width and 4 cm in thickness. By MRI the height is 3.5 cm. The volume as calculated by w x t x h x 0.52 (ellipsoid formula) is 29 cm 3 , which corresponds to the volume measured by volumetry (76). The dorsolateral extension into the left parametrium is maximal 3 cm from the uterine canal (compare Fig 14.14A for endocavitary brachytherapy of this patient).