Target movement during each IMRT sessions.


In IMRT, the intensities of each ports are not homogenous. So theoretically, several °∆hot spots°« or °∆cold spots°« will be made when target or OARs (Organ at Risk) are moving during each treatment sessions.

This animation simulates imaginary the movement of target (Prostate) and MLC. If target moves for the direction of MLC movement, the posterior side of prostate will be irradiated higher dose.

In Tomotherapy, radiation port (slit like) mounted CT scanner-like ring gantry rotates 360 degrees during treatment sessions. It means that if target move out its slit, target will be not irradiated.


The movement of target during each treatment sessions has been studying around the world. But if possible, each ports had better homogenous during each sessions.


last modification date: 2007/03/05