A volumetric analysis of GTVD and CTVHR as defined by the GEC ESTRO recommendations in FIGO stage IIB and IIIB cervical cancer patients treated with IGABT in a prospective multicentric trial (EMBRACE)

In patients with FIGO stage IIB and IIIB disease, intra-FIGO stage heterogeneity and overlap between the two stages exist with respect to tumor volume, treatment response and extent of parametrial disease at BT. Taking into account GTVD, parametrial disease at BT and the ratio of CTVHR/GTVD, five major groups exist. These enable prediction of GTVBT and CTVHR dose coverage through BT. IGABT, as performed in EMBRACE, accommodates to a considerable degree for the different variants of tumor regression in these groups through adaptation of the treatment technique including the use of needles. However, major variations remain at present with regard to dose to GTVBT and to CTVHR, which are most pronounced in G4 and G5. This new classification will be validated in future in regard to clinical outcome in EMBRACE.