Intensity-Modulated Radiation Therapy (IMRT)

What is intensity-modulated radiation therapy (IMRT)?

Intensity modulated radiotherapy (IMRT), volumetric arc therapy (VMAT) and tomotherapy further improve the shaping of a radiation dose to match the tumour shape, compared to 3D conformal radiation therapy (3D-CRT).

In 3D-CRT, the shape of the radiation dose are essentially limited to simple squares or rectangles because of the uniform intensity across each radiation field.

In IMRT, VMAT or tomotherapy, use of a greater number of radiation fields combined with variation of beam intensity within each radiation field allows the oncologist to create any shape to match the tumour and spare normal organs.

For example, where a tumour wraps round a normal organ, IMRT, VMAT and tomotherapy can create a C-shaped radiation dose to treat the tumour and spare the normal organ in the centre. Whereas in 3D-CRT, the central normal organ would get the same full dose as the surrounding tumour.

IMRT, VMAT and tomotherapy use different methods to achieve the same dose-shaping outcome and are largely interchangeable.

IMRT and image-guided radiation therapy

Image-guided radiation therapy (IGRT) can be used to complement IMRT to improve the positional accuracy of the radiation therapy treatment. IGRT uses imaging technology such as X-rays to visualise the position of the tumour so that radiotherapy can be delivered accurately.

Why do you need IMRT?

IMRT has several advantages such as:

  • Improved cure rates. Higher doses of radiation can be given to treat the tumour.
  • Fewer side effects. Concentrating the radiation beams at the target allows us to limit side effects by avoiding or reducing exposure to the surrounding healthy tissue.
  • Option of re-treatment. If re-treatment is needed, IMRT is preferred to reduce injury to normal organs.
  • More people can be treated. Radiation therapy allows your tumour to be treated even if it is difficult to reach or is located close to an important organ.
  • Better quality of life. Your body recovers better with IMRT than with conventional radiation therapy.

What are the risks and complications of IMRT?

Radiation therapy can cause side effects. They may be the result from the treatment itself or from radiation damage to the healthy cells around the treatment area. Side effects may vary depending on the kind of tissue structures near the tumour being irradiated.

In rare instances, a new cancer different from the first one being treated may develop years later. After treatment, your doctor will regularly check for complications and recurrent or new cancers.

Find out more about the risks of radiation therapy.

Why choose Mount Elizabeth Hospitals?

Mount Elizabeth works closely with Parkway Cancer Centre to provide a suite of cancer treatments for our patients in Singapore and the region.

Our multidisciplinary team of radiation oncologists and other medical professionals work together to provide you with customised care and treatment through innovative cancer therapies, including intensity-modulated radiation therapy (IMRT).

Supported by modern technology and facilities, we offer comprehensive cancer care with a focus on good outcomes and quality of life.

Our radiation oncologists

Our team of oncology specialists combine personalised care and the use of innovative medical technologies such as intensity-modulated radiation therapy (IMRT) across their treatment of different cancers.

Please check with your insurance provider for more information, and for their most up-to-date list of panel doctors.

^Specialists may qualify to be on the Extended Panel (EP). You may enjoy selected panel benefits depending on your policy and riders.
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