The present invention relates to a gas turbine blade (1) having a casted metal airfoil (2), said airfoil (2) comprising a main wall defining at least one interior cavity (9), having a first side wall (3) and a second side wall (4), which are coupled to each other at a leading edge (5) and a trailing edge (6), extending in a radial direction from a blade root (7) to a blade tip (8) and defining a radial span from 0% at the blade root (7) to 100% at the blade tip (8), wherein said main airfoil (2) has a radial span dependent chord length defined by a straight line connecting the leading edge (5) and the trailing edge (6) as well as a radial span dependent solidity ratio of metal area to total cross-sectional area, characterized in that solidity ratios in a machined zone of the airfoil (2) from 80% to 85% of span are below 35%, in particular all solidity ratios in said zone.