The invention provides a method and a device for estimating
dose distribution change, and a method and a
system for direct
machine parameter optimizing. The
estimation method comprises the following steps of determining the
initial dose distribution before a blade is moved; in the
initial dose distribution, determining the
dose change influence range caused by the blade moving; for an interest point in the
dose change influence range, according to the
initial dose distribution, obtaining the initial dose of the interest point before the blade moving, determining a reference point correlated with the interest point because of the blade moving, and according to the dose of the reference point in the initial
dose distribution, obtaining the current dose of the interest point after the blade moving; according to the initial dose and the current dose of the interest point, calculating the dose change of the interest point. The
estimation method has the advantages that the
estimation accuracy on the
dose distribution change is higher, the calculation speed is high, the calculation amount is less, the memory occupation is less, and the like.