Conventional treatment plan for pelvic tumors	IMRT plan for pelvic tumors

Intensity Modulated Radiation Therapy (IMRT) is a method used to conform radiation treatment dose to a target volume. IMRT uses advanced mechanical and computing technology that adjusts the shape of the radiation field and its intensity. This ‘sculpts’ or ‘paints’ the dose precisely to the affected area. Combining this with multiple fields allows the treatment to be delivered to the target site while avoiding normal tissue and critical structures.

IMRT differs from conventional 3-D radiation therapy, which uses static field sizes and uniform intensity to deliver the dose for each field. IMRT makes use of dynamic “leafs” which move in and out of the field throughout its delivery. This complex, orchestrated movements modulates the dose delivered at every point in the field. The main purpose of IMRT is to deliver the same quality of treatment while reducing toxicity and patient complications. In receiving an IMRT treatment, the patient can benefit in multiple ways. First, normal tissue dose, or dose to critical organs, can be greatly reduced. A patient received IMRT has a lower probability of toxicity and radiation induced complications. Second, local control of the tumor can be increased by allowing higher doses to be delivered with fewer side effects thereby improving the success of the treatment.