Sphericity is calculated by comparing the volume of the tumor to that of a sphere having the same surface area. The formula for sphericity is given by:
Sphericity = (pi^(1/3) * (6 * Volume)^(2/3)) / Surface Area
A perfect sphere has a sphericity of 1, while irregular shapes have values less than 1. Measurements are often obtained from medical imaging techniques such as MRI or CT scans, which provide detailed 3D representations of tumor structures.
