Advances in radiotherapy dosimetry and patient care

Dedicated IMRT optimization can generate a highly conformal non-uniform dose distributions leading to the optimal biological effects. If there were no intra-fraction motion management technique involved, then the attempt to optimize delivery will most likely smear the dose or even worse, the interplay of intra-fraction motion and IMRT beam motion will result in hot or cold spots throughout the field. A number of novel intra-fraction motion management techniques for adaptive 4D TomoTherapy/TopoTherapy treatment such as 3.5D, Breath hold delivery, Breath synchronization planning and delivery (BSD), Gated Tomo delivery (TomoGate), Real time motion adaptive delivery (RMAD) and real time motion adaptive optimization (RMAO) will be discussed. Primary objective of this presentation is to describe recent developments in the real time respiration monitoring during the radiotherapy treatment delivery. Primarily non-invasive approaches will be discussed. Major emphasis is to deliver accurate dose to the tumor while achieving at the same time reduction in the volume of normal tissue being irradiated to high dose. These approaches would enable adjustment of margins to account for motion. Radiation treatment at a higher dose will be achieved at a constant level of normal tissue toxicity, which can potentially yield increased local control. The presented methodology will show that real time motion tracking during the delivery of radiotherapy is feasible