Intensity modulated Radiation Therapy (IMRT) is a type of conformal radiation, which shapes radiation beams to closely approximate the shape of the tumor. The intensity of the radiation in IMRT can be changed during treatment to spare more adjoining normal tissue than is spared during conventional radiation therapy. Because of this an increased dose of radiation can be delivered to the tumor using IMRT.

How does it work?

IMRT utilizes beams shaped by multileaf collimators (MLCs) that move in and out of the beam’s path during treatment, varying the radiation beam intensity across the targeted field.

A combination of such beams of varying intensity allows a highly sculpted three dimensional distribution of radiation, maximizing dose to the tumour while reducing or even avoiding healthy tissues. Advanced computer planning helps to find the best combination of beams to achieve the desired results.

Benefits of IMRT

  • Treatment is delivered with precise accuracy, thus minimizing the effect on
    surrounding normal tissues and organs
  • High therapeutic ratio (maximum tumour control and minimum side effects)
  • Treated on an outpatient basis
  • As side effects are reduced, patients can resume their normal activities earlier

Am I suitable for IMRT ?

Currently, IMRT is being used most extensively to treat cancers of the prostate, head and neck, gastrointestinal, gynaecologic malignancies, sarcomas and central nervous system. IMRT may also be beneficial for treating pediatric malignancies.

However, IMRT may not be suitable for all situations, so a radiation oncologist will determine the suitability based on the tumour position, age and comorbidity and recommend the most appropriate treatment technique.

Our Cancer Specialists


Dr. Jonathan Teh Yi Hui

Medical Director (CSR) & Senior Radiation Oncologist

Stereotactic Radiosurgery (SRS/SBRT), Head & Neck, Pediatric, Urologic, Gastrointestinal Cancers & Sarcoma


Dr Daniel Tan Yat Harn

Director & Senior Radiation Oncologist

Stereotactic Radiosurgery (SRS/SBRT), Brain and Spine, Breast and Prostate Cancers


Dr David Tan Boon Harn

Medical Director (AARO) & Senior Radiation Oncologist

Stereotactic Radiosurgery (SRS/SBRT), Gynaecological, Gastrointestinal & Lung Cancers

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