Intensity modulated radiation therapy (IMRT): a new promising technology in radiation oncology.

Intensity modulated radiation therapy (IMRT) is a new technology in radiation oncology that delivers radiation more precisely to the tumor while relatively sparing the surrounding normal tissues. It also introduces new concepts of inverse planning and computer-controlled radiation deposition and normal tissue avoidance in contrast to the conventional trial-and-error approach. IMRT has wide application in most aspects of radiation oncology because of its ability to create multiple targets and multiple avoidance structures, to treat different targets simultaneously to different doses as well as to weight targets and avoidance structures according to their importance. By delivering radiation with greater precision, IMRT has been shown to minimize acute treatment-related morbidity, making dose escalation feasible which may ultimately improve local tumor control. IMRT has also introduced a new accelerated fractionation scheme known as SMART (simultaneous modulated accelerated radiation therapy) boost. By shortening the overall treatment time, SMART boost has the potential of improving tumor control in addition to offering patient convenience and cost savings.