Intensity modulated radiation therapy (IMRT) for rectal cancer by prolonged course (case series)

Intensity modulated radiation therapy (IMRT) is an advanced radiation technique employing recent innovations in imaging and computer technology. Physicians at UCSF have used IMRT to treat cancer patients since 1997, giving us more experience with IMRT than most other centers in the United States and the rest of the world. IMRT planning starts with tumor target and normal tissue definition, followed by inverse planning. Using computer optimization, multiple small fields are designed to give a complex and conformal radiation dose distribution, which provides the prescription dose to the tumor target and minimizes dose to regional normal tissues.