How can use roipoly in a 3D image?

I have created a code in which I use ginput, roipoly and imcrop in order to select a ROI from a 2D slice. How can I do that in a 3D image(for every slice)?

[x,y]=ginput;
BW = roipoly(ROI, x, y);
 ...
A=ROI .*BW;
Final=imcrop(K);
figure; imagesc(Final); axis equal; colormap(gray); colorbar;