Methods for developing and using treatment plans with improved modulation for radiation therapy are disclosed. The methods involve adding an extra component to the patient-related objective function in order to make the optimization algorithm used to develop the treatment plan arrive at a solution with increased modulation. The extra component may take many forms. For example, the user may specify that the treatment plan favor solutions using a range of monitor units. The present invention is particularly useful in conjunction with radiotherapy systems having multileaf collimators for beam shaping, and in connection with advanced radiotherapy techniques, such as IMRT and arc therapy.