Commissioning and management of stereotactic radiotherapy and intensity modulated radiotherapy

This paper explained the points that should be kept in mind when implementing stereotactic radiotherapy or intensity-modulated radiotherapy (IMRT) using a linac device. The items to be considered in the introduction of stereotactic radiotherapy (intracranial site and head/neck) are explained in the following order: (1) before introduction, (2) from equipment installation to linac equipment acceptance test, (3) beam data acquisition, (4) modeling - commissioning, (5) simulation and the examination of patient fixation device, (6) examination of therapy plan, and (7) start of usage. In addition, the reference data for isocenter accuracy should be acquired in advance. As the definition in insurance practice, the position accuracy of irradiation center must be within 2 mm. In commissioning, in addition to the commissioning of normal irradiation, the dose calculation accuracy of a small irradiation field should be evaluated. In the introduction of stereotactic radiotherapy (trunk), there is a slightly different point at the start-up: the response to respiratory movements and heterogeneous tissue peculiar to the trunk should be examined. The matters to be considered in the introduction of IMRT were also detailed. In IMRT, the control of multi-leaf collimator (MLC) position accuracy is an important item, and changes in leaf gap width have a large effect on dose. DMLC power ratio test should be performed as soon as possible after the acceptance test has been completed to obtain reference data. In addition, as well as the accuracy control of IMRT devices, it is required to perform the dose verification for individual patient prior to treatment. (A.O.)