Intensity-Modulated Radiation Therapy (IMRT)

Intensity-Modulated Radiation Therapy (IMRT) is a high-precision radiotherapy modality that uses computer-controlled linear accelerators to deliver precise radiation doses to a malignant tumor or specific areas within the tumor.

How IMRT Works

IMRT allows the radiation oncologist to divide the radiation beam into hundreds of smaller, individual 'beamlets'. The intensity of each beamlet can be adjusted independently. This modulation enables the sculpting of a high radiation dose that conforms tightly around the outer contours of the tumor while creating steep drop-offs of dose near critical healthy structures (such as the spinal cord, brainstem, or salivary glands).

Clinical Importance in Head & Neck Cancers

IMRT is particularly vital for head and neck cancers, where tumors are located adjacent to crucial organs. Conventional radiation often leads to permanent xerostomia (dry mouth) due to salivary gland exposure. IMRT allows the radiation team to spare the parotid glands, significantly preserving post-treatment salivary function and improving long-term quality of life.