He is a leading authority on a variety of radiation treatments for cancer, including intensity modulated radiation therapy (IMRT) and high dose rate (HDR) brachytherapy. DiPetrillo is a pioneer in the use of IMRT, a noninvasive procedure that allows physicians to pinpoint delivery of radiation therapy, resulting in better tumor control with less toxicity. He is also an expert in the use of HDR brachytherapy, a treatment that involves the use of a robotic arm to deliver a radioactive “seed” to a tumor.