Table 1.

Recommendations for target definition according to EORTC, RTOG and ESTRO-ACROP

Contouring approach	Dose prescription	GTV	CTV
EORTC single phase	30 × 2.0 Gy	Resection cavity + residual T1 enhancement	GTV + 2 cm
RTOG two phases	23 × 2.0 Gy	GTV1: Resection cavity + residual T1 enhancement + FLAIR abnormality (oedema)	CTV1 = GTV1 + 2 cm (the margin is 2.5 cm in cases where no oedema is presented)
	+ 7 × 2.0 Gy	GTV2: Resection cavity + residual T1 enhancement	GTV2 + 2 cm
ESTRO-ACROP	30 × 2.0 Gy	Resection cavity + residual T1 enhancement + FLAIR abnormality (oedema) for secondary glioblasomas	GTV + 2 cm

Abbreviations: EORTC = European Organisation for Research and Treatment of Cancer; ESTRO-ACROP = European Society for Radiotherapy & Oncology - Advisory Committee on Radiation Oncology Practice; CTV = clinical target volume; FLAIR = Fluid-attenuated Inversion Recovery. GTV = gross tumor volume; RTOG = Radiation Therapy Oncology Group