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What is intensity-modulated radiation therapy?

Intensity-modulated radiation therapy (IMRT) is a highly precise radiation therapy technique that modulates the dose of radiation, based on the shape of the tumor, to deliver a sufficient dose to the tumor while sparing healthy tissue. This is a recent advance in the delivery of radiation that allows for very little collateral impact to surrounding tissues or organs, which is especially important in vital areas. 

Tumors can often be irregularly shaped and these odd shapes can pose problems when treated with radiation delivered in straight lines. The software used in IMRT matches the exact shape of the tumor to deliver radiation with greater precision, using modified intensity “beamlets.” Because IMRT conforms the radiation dose to the target area, it is typically used to treat difficult-to-reach tumors.

Why it's done

IMRT is used to treat cancerous and noncancerous tumors and is ideal for treating tumors located very close to sensitive structures and organs, including:

  • Brain tumors
  • Breast cancer
  • Esophageal cancer
  • Liver cancer
  • Lung cancer
  • Lymphoma
  • Pancreatic cancer
  • Skull base tumors
  • Soft tissue sarcoma
  • Stomach cancer

Our approach

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

IMRT 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 IMRT, 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 IMRT 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 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 IMRT, will review all treatment options and discuss the risks specific to your treatment.

IMRT typically requires multiple treatment sessions. The type, location and size of your tumor, as well as your overall health, will determine the total number of IMRT sessions and radiation dose needed. Patients are often scheduled for IMRT sessions five days a week for five to eight weeks.

During each treatment session, you will be placed on a treatment table. You may need to be repositioned during the procedure, which typically lasts between 10 and 30 minutes. There is no pain during IMRT treatments.

Because IMRT treatment is an outpatient procedure, you will be observed for a period of time and then discharged home.

Possible side effects

With IMRT, 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 include:

  • Fatigue
  • Hair loss
  • Mouth problems or difficulty swallowing
  • Digestion problems
  • Diarrhea
  • Nausea and vomiting
  • Headaches
  • Soreness in the treatment area
  • Urinary difficulties

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. Over-the-counter medications, such as Tylenol or Motrin, can alleviate any discomfort.

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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