A treatment planning system is used as a step in the treatment planning process for radiation therapy. It provides computerized methods for creating beam arrangements and calculating dose distributions for patient specific anatomy. Before clinical use, the TPS goes through a commissioning process where beam measurements and parameters are entered into the system, and the commissioner confirms functionality and accuracy on all system components. Once in use, certain parameters, or data within the TPS may deviate from that established during commissioning, which may be due to vendor updates or user changes. To avoid errors in the treatment planning process, a review of any of these changes should be done through a routine quality assurance check.