Dalhousie University

Robert Lee MacDonald

Alasdair Syme

Christopher G Thomas

Brian Little

Methods and systems for radiation treatment planning and delivery apply a CODA cube. Cost values in the CODA cube may be used in the optimization of couch, collimator, and gantry angles simultaneously. Trajectories generated using the CODA cube show significant benefits when compared to conventional VMAT. A statistically significant sparing to OAR maximum radiation doses was seen. CODA plans resulted in a reduction to maximum radiation dose in OARs of 20.6% (p<0.01), with maximum brainstem radiation dose decreased by 2.63 Gy (p=0.031) on average. Mean reduction in total MU was 8.6% (p=0.156), and a mean decrease in non-target brain tissue receiving 12 Gy or higher was 3.9% (p=0.16), when compared to standard VMAT methods (n=7).

Systems and methods for planning, controlling and/or delivering radiotherapy and radiosurgery using combined optimization of dynamic axes (CODA)

A radiation treatment planning system and method for generating plans to treat plural target volumes, each associated with a prescribed dose, does not require delivery of radiation to every target volume from every beam direction. Allowing target volumes to be omitted for some control points facilitates generation of treatment plans that deliver less radiation dose to non-target tissues by allowing beam shaping to more closely fit the remaining target volumes. Simulated annealing using an objective function may be applied to determine parameters such as the number of control points for which a target volume is not targeted.

Coordinated radiotherapy for plural targets

Generating a plan for radiation treatment of multiple target volumes such as, for example, multiple brain tumors, involves optimizing a grouping of the target volumes into subsets and generating treatment plans for each subset. Resulting treatment plans may minimize radiation dose to tissues outside of the target volumes. A radiation treatment planning system may be configured to operate in this manner and to upload control signals which cause a radiation therapy device such as a linear accelerator to execute the radiation treatment plans.

Radiation treatment planning with multiple target subset optimization

Systems and methods are provided for determining an angular trajectory for dynamically rotating a multileaf collimator during arc therapy. According to various embodiments, a suitable collimator trajectory may be determined based on the reduction or minimization of a residual unblocked area residing between a planning target volume and leaves of the multileaf collimator in the beam's eye view over the set of control points corresponding to an arc therapy plan. Various example methods are provided for determining collimator trajectories based on whitespace reduction, and for providing quantitative measures of whitespace optimization associated with a given trajectory. In some embodiments, the whitespace may be calculated using terms that account for the overlap of a planning target volume with an organ at risk of exposure.

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Antigonish, Canada

Robert Lee MacDonald