A dome structure for a combustor of a gas turbine includes a frame structure extending circumferentially about a combustor centerline axis, and a plurality of integrated dome-deflector plate members mounted to the frame structure. Each of the plurality of integrated dome-deflector plate members includes a dome wall, a deflector wall, and a plurality of side walls connecting the dome wall and the deflector wall to each other. A cavity is defined by the dome wall, the deflector wall, and the plurality of side walls.