Intensity modulated radiation therapy (IMRT) precisely targets cancer cells while reducing the radiation dose to healthy organs. This technique is possible due to advanced radiation therapy machines equipped with a multileaf collimator (MLC) system. The MLC consists of hundreds of independently moving lead leaves that shape the radiation beam to match the tumor's exact contours. These leaves open and close rapidly, within tens of milliseconds, allowing a single radiation beam to be divided into hundreds of "beamlets" with varying intensities, creating a flexible radiation distribution pattern.

According to Master of Science, Doctor Vuong Ngoc Duong, Deputy Head of Radiation Therapy at Tam Anh General Hospital Hanoi, intensity modulated radiation therapy offers several advantages over other conventional radiation techniques. Currently, IMRT is applicable to most cancers and tumor locations indicated for radiation. However, it is more commonly used for tumors adjacent to critical structures such as those in the head and neck, nasopharynx, breast, prostate, and lung.

High precision

Intensity modulated radiation therapy allows radiation beams to conform closely to complex tumor shapes, precisely defining the treatment area. This is particularly effective for hard-to-reach tumors or those located near vital organs such as the brain, nasopharynx, and esophagus.

Protecting healthy tissue and sensitive organs

This method creates a rapid intensity drop at the boundary between the tumor and healthy tissue, shielding sensitive organs from excessive radiation. For instance, in head and neck cancer treatment, intensity modulated radiation therapy significantly reduces radiation exposure to the spinal cord, brainstem, optic nerves, and parotid glands, thereby preventing damage. By minimizing harm to healthy tissue, patients experience fewer side effects compared to conventional radiation techniques.

Doctors, medical engineers, and technicians check a patient's position for radiation therapy. *Photo: Tam Anh General Hospital*

Increased treatment effectiveness

Due to its optimal dose distribution capabilities, intensity modulated radiation therapy allows doctors to deliver higher radiation doses directly to the tumor compared to other conventional techniques. This enhances the effectiveness of radiation therapy and improves disease control without increasing the total radiation dose received by the patient.

Shortened treatment time

This radiation therapy delivers different dose levels to various regions within a single treatment session, enabling simultaneous treatment of multiple organs. For example, a patient with nasopharyngeal cancer can receive radiation to both the nasopharynx and cervical lymph nodes in the same course, reducing overall treatment time.

Doctor Duong advises cancer patients to seek care at multi-specialty hospitals equipped with advanced, synchronized radiation therapy units for proper examination, consultation, and treatment.

Thanh Long

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