Table 1.

Comparison of technologies used to create GRID dosimetry

	Pros	Cons
Collimator block	• Cost-effective • Reusable • Can be customized to specifications • Adjustable field by closing jaws	• Made to order • Limited to 1 pattern • Heavy • Necessary to mount and dismount
Multileaf collimator	• Available in most institutions • More flexible in creating field pattern	• Long delivery time • Requires more monitor units • More radiation leakage • Higher valley-to-peak doses • Higher surface doses
Hybrid collimation	• Easier to craft • Lighter than block • Faster than multileaf collimator	• Valley-to-peak ratio lower along diagonals