Varian Medical Systems International Ag

Tuomas Erik Torsti

Esa Kuusela

Sami P Siljamaki

Janne Ilmari Nord

Janne Iimari Nord

Juha Kauppinen

Christopher Boylan

Marko Rusanen

Viljo Petaja

Ari Harju

Laura Kristiina Korhonen

Risto Ahonen

Petri Kokkonen

Timo Ikonen

Antti Karjalainen

Petri Hiltunen

A method of calculating radiation dose includes dosimetric projection of a collimator geometry. The method includes defining a three-dimensional (3D) geometry of a collimating device which defines an aperture configured to allow a radiation beam passing through, projecting the collimating device along the radiation beam into a two-dimensional (2D) geometry in a plane, calculating dosimetric opacity values of the collimating device at locations adjacent to the aperture based on the 3D geometry of the collimating device, and calculating transport of the radiation beam through the collimating device based on the 2D geometry projected in the plane and using the dosimetric opacity values of the collimating device at the locations adjacent to the aperture.

Dosimetric projection of collimator geometry

A portal imaging device is used to determine an amount of radiation that is delivered to at least one point while administering a radiation treatment therapy to a patient. Upon detecting that the amount of radiation that is delivered to that at least one point exceeds a predetermined amount of radiation (for example, a planned amount of radiation per the radiation treatment plan), administration of radiation treatment therapy to the patient can be automatically halted.

Radiation treatment platform and method using a portal imaging device to automatically control therapy administration

A method and system for providing intensity modulated radiation therapy to a moving target is disclosed. According to a preferred embodiment of the invention, a treatment plan for providing radiotherapy using a multi-leaf collimator ('MLC') comprises a plurality of sub-plans, each of which is optimized for a different phase of target movement. Movements of the treatment target are tracked in real time, and the choice of which sub-plan to implement is made in real time based on the tracked position of the target. Each of the sub-plans is preferably formulated to minimize interplay effects between target movements and MLC leaf movements, consistent with other planning goals. In addition, the sub-plans preferably include a predicted region corresponding to the next anticipated position of the target, in order to facilitate the transition to the next position.

Method and system for treating moving target

A method is proposed for accurate and efficient modeling of head scatter phase space for treatments with dynamic jaws. Specifically, the method enables the efficient calculation of the head scatter phase space in case of a dynamic treatment where jaws and MLC leaves move during the delivery. In one embodiment, the invention can be used to calculate the head scatter contribution during final dose calculation of dynamic treatments. This novel method also enables an accurate calculation of the head scatter contribution from optimal fluence and from jaw positions without having to calculate the leaf sequence. In this embodiment, the invention can be used in optimization of large field IMRT treatments.

Method for calculating head scatter phase space for radiation treatment using a multi-leaf collimator with dynamic jaws

A method of providing intensity modulated radiation therapy to a moving target is disclosed. The target moves periodically along a trajectory that is projected onto a multi-leaf collimator (MLC) plane. The MLC plane is divided into thin slices parallel to the movement of the target. The present invention optimizes the leaf sequence such that, within each slice, if a point receives radiation, all other points in that slice that receive the same amount or more fluence are also receiving radiation at the same time.

Leaf sequencing algorithm for moving targets

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Espoo, Finland

Tuomas Erik Torsti