Patent Number: 
Section: claims

1. An improved method of calculating a radiation dose for a radiation treatment using a multi-leaf collimator for patients that will be treated with radiation therapy using the multi-leaf collimator comprising:providing a multi-leaf collimator comprising leaves of a tongue-and-groove design, the leaves having lateral edges and tip ends, wherein the lateral edges will be exposed to radiation during a treatment protocol,testing the multi-leaf collimator to determine a shape of a tongue-and-groove width, andsubtracting the shape of the tongue-and-groove width from a fluence map used for radiation dose calculations,wherein an amount subtracted depends on a distance from a tip end of each leaf to a point on each leaf, andwherein the amount subtracted comprises a non-constant width at the lateral edges of the leaves that are exposed to radiation and a constant transmission through the non-constant width is considered. 2. The improved method of claim 1, wherein the testing comprises asynchronous sweeping gap tests with different shifts s between adjacent leaf positions. 3. The improved method of claim 1, wherein the testing comprises asynchronous oscillating sweeping gap (aOSG) tests with different shifts s between adjacent leaf positions. 4. The improved method of claim 1, further comprising calculating an area A(s) of a tongue-and-groove profile area between each tip end and a point on each leaf. 5. An improved method of calculating a radiation dose for a radiation treatment using a multi-leaf collimator for patients that will be treated with radiation therapy using the multi-leaf collimator comprising:providing a multi-leaf collimator comprising leaves of a tongue-and-groove design, the leaves having lateral edges and tip ends, wherein the lateral edges will be exposed to radiation during a treatment protocol,determining a shape of a tongue-and-groove width by testing the multi-leaf collimator, andsubtracting the shape of the tongue-and-groove width from a fluence map used for radiation dose calculations,wherein an amount subtracted depends on a distance from a tip end of each leaf and a point on each leaf, andwherein the amount subtracted comprises a constant width at the lateral edges of the leaves that are exposed to radiation and a variable transmission through the constant width is considered. 6. The improved method of claim 5, further comprising obtaining the variable transmission with numerical methods taking into account a geometry of the leaves and a radiation transport across the multi-leaf collimator. 7. The improved method of claim 5, wherein the determining comprises testing the multi-leaf collimator by asynchronous sweeping gap tests with different shifts s between adjacent leaf positions. 8. The improved method of claim 5, wherein the determining comprises testing the multi-leaf collimator by asynchronous oscillating sweeping gap (aOSG) tests with different shifts s between adjacent leaf positions. 9. The improved method of claim 5, further comprising calculating an area A(s) of a tongue-and-groove profile area between each tip end and a point on each leaf.