IGRT or Image Guided Radiation Therapy, according to Consultant Oncologist & Radiotherapist Dr Shum Weng Yoon, is the next step in radiation therapy, aimed at improving accuracy in radiation field placement and decrease radiation doses to small tissues.
Touted as the most advanced radiation therapy today, IGRT minimises sides effects and improves treatment outcomes.
Before the IGRT radiation beam is turned on, doctors, such as Dr Shum, and radiation therapists will use an imaging tool to determine the precise location of the tumour. Imaging enables a smaller radiation field to be achieved, maximising radiation to the tumour and minimising radiation damage to normal tissues.
Most cancers will benefit from treatments that are more accurate and precise. Tumours of the prostate, head and neck, and, the lung is better treated with IGRT to ensure that delicate tissues such as the rectum, urinary bladder, spinal cord and salivary gland are spared from radiation.
Take, for example, the treatment of prostate cancer.
“We see significant benefits in treating prostate cancer using IGRT. As the bladder fills and empties, the prostate moves, sometimes significantly.”
“This means that the prostate will be at different positions for each day of the radiation treatment.”
At Mahkota Medical Centre, IGRT is used to determine the position of prostate just before radiation is delivered.
Patients need to undergo a CT simulation before radiation therapy is carried out. The images produced from the CT simulation will be used to formulate a customised treatment plan for every patient.
During treatment, the patient is comfortably seated on a treatment couch in the same position as planned from the reference imaging dataset. A read time x-ray and Computer Tomography will be taken before radiation therapy.
After referring to the images produced from the CT simulation, radiation therapy is administered externally vial the Linear Acceleration in regimented doses. The 15-20 minute treatment is pain-free.
Radiation therapy is given five days a week, with the whole treatment duration varying from one to seven-week depending on size, location and type of cancer.