The use of small specimen test techniques (SSTT) to determine mechanical properties of irradiated materials has been studied over the previous decades both in fission and fusion programs, but also to characterise and optimise new materials by nuclear and non-nuclear communities. Currently a number of activities are running that focus on the standardisation of the use of SSTT to determine fracture toughness properties for fusion reactor materials (IAEA , EUROfusion , F4E ), and long-term operation of LWR (CRIEPI ). In fact, the determination of the T0 reference temperature (ASTM E1921 ) has been successfully determined by testing small specimens (W=8mm, B=4mm) of non-irradiated and irradiated pressure vessel materials. However, some concerns exist about the use of the Master Curve on ferritic-martensitic steels, not only with SSTT but also with 1T CT specimens. The main concern is the slope of the MC [7, 8], that seems to be steeper than the standard one. In this paper, the fracture toughness of Eurofer97 has been obtained by testing small CT specimens with the geometry selected in IFMIF-DONES (W=9.2mm, B=4.6mm) in the transition region. T0 has been determined and compared to the one obtained from 0.5T CT specimens. The scatter of the results has also been assessed to validate the scatter description of the MC.