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What is image-guided radiation therapy (IGRT)?

Image-guided radiation therapy (IGRT) uses X-ray, cone-beam CT scanning, electromagnetic tracking, optical surface tracking and/or ultrasound imaging during treatments to locate and focus radiation beams precisely at the tumor(s) being treated.

Why it's done

Tumors can shift in the body because of breathing or other bodily movements. In order to deliver precise treatment, IGRT sets up the radiation exactly on target. Pictures are taken before, and even during, the time that radiation is being delivered to confirm that the alignment is pinpoint perfect.

The physicians compare images taken during a treatment simulation to past and new images taken of the patient’s tumor. Based on this comparison, and taking into account any movement of the tumor, the physician can make necessary adjustments to precisely target the tumor and avoid healthy tissue.

IGRT is used to treat cancerous and noncancerous tumors and is ideal for treating tumors located very close to sensitive structures and organs.

Our approach

At Northwell Health Cancer Institute, IGRT is one of many advanced radiation therapies used to treat malignant and benign tumors while minimizing damage to healthy tissue. By using IGRT, our physicians can deliver high-energy beams of radiation to a targeted area.

IGRT treatment is provided in a caring and professional environment by specialists dedicated to making each patient visit as informative and stress-free as possible. This begins with an in-depth conversation describing the treatment, including what to expect, possible side effects and goals. The personalized treatment also includes careful consideration of current health, family history, age and patient preferences.

All radiation therapies, including IGRT, are administered using evidence-based medicine. A multidisciplinary team of doctors, including radiologists, surgeons, pathologists, medical oncologists and radiology oncologists, collaborates on treatment plans to ensure that every aspect of treatment is precisely coordinated for the best possible outcome. This includes ongoing peer review and chart rounds.

Because convenience is a priority, we offer multiple locations for radiation therapy to enable you to obtain treatment near where you live or work. 

Research at Northwell

Advances in radiation oncology are continuously happening at Northwell Health Cancer Institute, allowing us to provide better care and more innovative technologies and treatments for patients. Through alliances with leading research organizations such as Cold Spring Harbor Laboratory, we participate in investigator-initiated trials to offer the most leading-edge therapies available. 

Northwell Health Cancer Institute is recognized worldwide for its commitment to providing pioneering treatment for cancer patients. Our ongoing focus on improving cancer treatments has contributed to significant advancements that are improving quality of life and survival rates for cancer patients.

Learn more about clinical trials and research happening at Northwell Health Cancer Institute.

What to expect

Prior to the IGRT procedure, you will be asked to provide a complete medical history and may have to undergo a thorough physical examination to ensure you are in good health. Blood tests and other diagnostic tests may be performed. It is important for you to notify your healthcare provider about any sensitivities or allergies to medication, latex, tape, contrast dyes, iodine or anesthetic agents.

Your attending radiation oncologist, who will be treating you with IGRT, will review all treatment options and discuss the risks specific to your treatment.

Your IGRT treatment team may use a variety of imaging techniques to ensure that your treatment is precisely focused on the tumor to protect nearby healthy cells and organs. Before and during the procedure, imaging tests may be performed. These images are compared to help position your body and your treatment to target the tumor.


Because IGRT treatment is an outpatient procedure, you will be observed for a period of time and then discharged home. You will not likely have a great amount of pain from the procedure. Over-the-counter medications, such as Tylenol or Motrin, can alleviate any discomfort.

Possible side effects

With IGRT, some patients have no side effects at all. However, when side effects do occur, they are typically related to the specific area(s) being treated. Side effects may include:

  • Fatigue
  • Mild skin reactions
  • Hair loss
  • Upset stomach

Most side effects usually go away after treatment ends. However, you may feel very tired for four to six weeks after your last treatment. Talk to your doctor about ways to treat potential side effects.

Support groups

Cancer is challenging, but you don’t have to go it alone. At Northwell Health Cancer Institute, a wide range of support groups are available to help you cope with diagnosis, treatment and post-treatment issues.

Learn more about support groups.

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