NCIt definition : The length of a straight line passing through the center of a circle or sphere and
connecting two points on the circumference.;
Alternative definition : CDISC: The length of a straight line passing through the center of a circle or sphere
and connecting two points on the circumference. (NCI); NCI-GLOSS: The length of a straight line that extends from one edge of a tumor or
other object, through its center and to the opposite edge. It is usually used to measure
the size of round or spherical shapes.;