System, process and apparatus to determine linac isocenter

A LINAC radiation isocenter determination process comprising:

• mounting a signal emitter module on a collimator;
• mounting a signal receiver module in a location with an unobstructed view of the signal emitter module;
• rotating the collimator with a gantry positioned at a first angle while the signal receiver module acquires signal emitter module positions;
• determining a calculated collimator axis of rotation from the signal emitter module positions acquired with the gantry positioned at the first angle;
• rotating the collimator with the gantry positioned at a second angle while the signal receiver module captures the signal emitter module positions;
• determining a calculated collimator axis of rotation from the signal emitter module positions acquired with the gantry positioned at the second angle;
• and
• determining LINAC radiation isocenter using the calculated collimator axis of rotation with the gantry positioned at the first angle and the calculated collimator axis of rotation with the gantry positioned at the second angle.

A LINAC gantry axis of rotation determination process comprising:

• mounting a signal emitter module on a collimator;
• mounting a signal receiver module at a location with an unobstructed view of the signal emitter module;
• and
• determining the gantry axis rotation by rotating the gantry while the signal receiver module acquires signal emitter module positions.

A LINAC collimator axis of rotation determination process comprising:

• mounting a signal emitter module on a collimator;
• mounting a signal receiver module at a location with an unobstructed view of the signal emitter module;
• and
• determining the collimator axis rotation by rotating the collimator while the signal receiver module acquires signal emitter module positions.

A LINAC couch axis of rotation determination process comprising:

• mounting a signal emitter module on a collimator;
• mounting a signal receiver module at a location with an unobstructed view of the signal emitter module;
• and
• determining the collimator axis rotation by rotating the couch while the signal receiver module acquires signal emitter module positions.

A collimator axis walkout determination process comprising:

• mounting a signal emitter module on a collimator;
• mounting a signal receiver module at a location with an unobstructed view of the signal emitter module;
• determining a path through space of the signal emitter module during the collimator rotation by analyzing signal emitter module positions;
• fitting the computed signal emitter module positions to a three-dimensions circle in space;
• and
• computing an error vector between each position and a nearest point to the fit three-dimensional circle.

A couch axis walkout determination process comprising:

• mounting a signal emitter module on a collimator;
• mounting a signal receiver module at a location with an unobstructed view of the signal emitter module;
• determining a path through space of the signal emitter module during couch rotation by analyzing signal emitter module positions;
• fitting the computed signal emitter module positions to a three-dimensions circle in space;
• and
• computing an error vector between each position and a nearest point to the fit three-dimensional circle.