Intensity Modulated Radiation Therapy


IMRT (Intensity Modulated Radiation Therapy) is a non-invasive procedure used to treat patients with a number of different kinds of cancer.  Using a high-precision radiation targeting system, IMRT is able to maximize the radiation delivered to tumors while minimizing damage to healthy tissue.  With years of specialized training and clinical success using this technology, our doctors are able to give our patients the best possible outcomes.

IMRT is delivered by specially equipped linear accelerators guided by a sophisticated computer system. The radiation beam generated by the IMRT system is shaped by 120 computer controlled multi-leaf collimators or “fingers” which allow exquisite conformality. Whereas traditional radiation treatments were delivered by 4-6 separate beams, IMRT employs hundreds of coplanar beams to precisely kill tumor cells.

This pinpoint accuracy of IMRT has several vital advantages for cancer patients. It allows maximization of dose delivery to the targeted tumor while minimizing healthy surrounding tissues from unnecessary exposure. As such, this theoretically will translate into higher local cure rates and fewer side effects from radiation treatments.

While IMRT has been employed successfully to treat many types of cancers, its benefits are apparent for prostate, lung, gastrointestinal, gynecological and head and neck cancer patients. Prostate cancer cells are relatively radio-resistant and require high doses for effective cure. This dose requirement is also compounded by its precarious anatomical location, as it is flanked by radiation sensitive structures such as the bladder and the rectum. Hence, IMRT allows for conformal dose delivery while minimizing the dose to the non-target tissues. Potential benefits of prostate IMRT include higher cure rates highlighted by lower chances of rectal bleeding and urinary complications.

It has also been proven to decrease side effects in patients with head and neck cancers treated with IMRT. Studies comparing IMRT to standard radiation showed less xerostomia (dryness of the mouth), less pain with swallowing, and less long-term complications. Our techniques allow less dose to be delivered to vital structures of the head and neck region involved in producing saliva and swallowing.

Breast cancer is another disease that may benefit from the unique attributes of IMRT. Particular with cancers of the left breast, which lies above the heart, IMRT offers an excellent therapeutic option. It allows a conformal dose distribution around the breast while minimizing any dose to the myocardium. Consequently, potential long term complications of cardiovascular disease and pericarditis can be minimized.

Brain tumor treatments are also being revolutionized by IMRT therapy. In particular, Princeton Radiation Oncology’s utilization of BrainLab’s micromulti-leaf system allows the most sophisticated radiation treatments to the central nervous system. Brain tumors are often irregularly shaped and almost always lie adjacent to vital non-target structures. Hence, IMRT’s elegant dose distribution is also ideal for brain treatments.