What is Image Guided Radiation Therapy (IGRT)?
Image-guided radiation therapy (IGRT) is that technique of radiotherapy verification in which high-precision three-dimensional images are taken to define how and where exactly the tumor volume of each patient is and where it is located during the duration of the treatment. It is a technique that allows greater precision at the moment of performing the radiation, thus adjusting the patient’s position and thus delivering the radiotherapy.
Why is it performed?
Image-guided radiation therapy (IGRT) is used to treat tumors located in areas of the body normally prone to movement (lungs, liver or prostate, for example) or those located near critical organs and tissues.
Importantly, it is a technique that is often combined with other advanced forms of high-precision radiotherapy, such as intensity-modulated radiation therapy (IMRT), proton beam therapy, stereotactic radiotherapy or stereotactic body radiation therapy (SBRT), which use computer-controlled X-rays to deliver precise radiation dosage to the tumor.
What does it consist of?
It consists of taking images before and during the administration of radiation, while the patient is lying on the treatment table, in order to delimit the tumor and thus improve the precision of the treatment, while preserving the surrounding healthy tissues. Thus, a high dose of radiation is emitted at the tumor from different angles with many very fine beams of light of varying intensity that surround the cancer cells, sparing healthy tissue. Because it applies smaller doses to normal tissues, it decreases side effects and improves the chance of eradicating the tumor.
Preparing for Image-Guided Radiation Therapy (IGRT)
Digital imaging scans are performed in pre-simulations to determine how advanced the disease is and to pinpoint the exact tumor to be treated. Thus, the scans are part of a computer-based treatment plan carried out on an individualized basis. Thanks to the simulations, the exact location is known and thus the volume of tissue treated is reduced, focusing only on the tumor.
Aftercare after the procedure
As irradiation in image-guided radiotherapy is performed on a smaller area of normal tissue, toxicity is reduced, which improves the patient’s quality of life and reduces side effects. However, the radiation oncology expert will recommend periodic visits to the patient to monitor the patient’s progress.