Techniques and systems for supplying fluid to a rotating gantry portion of a radiation treatment apparatus are disclosed where a first batch fluid is supplied to the rotating gantry when the rotating gantry is stationary a first time, discontinuing the supply when the rotating gantry is rotating, and supplying a second batch of fluid when the rotating gantry is stationary a second time. A storage component on the rotating gantry allows supplied fluid to be stored in the rotating gantry and used to shape a radiation beam and/or cool an ionizing radiation source, for example, while the rotating gantry is rotating. The techniques and systems may also be utilized to discharge a first fluid from the rotating gantry and supply a second fluid to replace the first fluid.