External Beam Radiotherapy

First, you will have a consultation with your Clinical Oncologist. The Clinical Oncologist will review all your medical records and will briefly explain the overall process of radiotherapy including:

• Why the treatment plan is best for you
• Type and dose of radiation therapy you will receive
• How the treatment is done
• Side effects

After that, you will undergo CT simulation. The CT simulation is performed using a CT scan machine to precisely identify the tumour’s location, shape, and size. Special accessories known as immobilisation devices are used to help ensure you maintain a consistent position throughout the process. CT simulation usually takes about 30 to 60 minutes, depending on factors such as the scanning technique, scan length, and the patient's condition. Prior to CT simulation, you are required to:

• Remove your necklace, earrings, any metal accessories, and any valuables in your pockets prior to the procedure
• Inform the medical personnel on your medical history (i.e. asthma, diabetes, drug or non-drug allergies, implanted pacemaker)

In treatment planning, advanced computer software is used to create a 3D/4D image of treatment area. The Oncologist uses the CT simulation images to delineate the tumour and the organ at risk. Then, the Medical Physicist develops the optimal treatment plan, ensuring maximum radiation dose to the target area while minimising exposure to healthy tissue.

For advanced radiotherapy treatments, independent quality assurance (QA) of the treatment plan is conducted by a Medical Physicist. This verifies that the delivered treatment aligns with the correct prescription and intent. This rigorous check ensures secure, accurate, and precise delivery of the plan for each patient undergoing advanced treatment.

The Radiation Therapist may use the machine’s imaging system to perform image verification by taking a new image of the tumour before treatment delivery to verify the correct target of treatment. If needed, adjustments are made to align your position precisely with the planned position.

Duration:

• Approximately 15 to 30 minutes for each session
• Daily treatment, five days a week, from Monday to Friday

Inside the treatment room, there is a machine called a Linear Accelerator (LINAC) which is used for radiotherapy treatment. The Radiation Therapist will instruct you to lie down on the table and they will adjust your treatment position based on marks on your skin from the CT simulation. You will be continuously monitored by the Radiation Therapist outside the LINAC room.

During treatment delivery, the LINAC will rotate around you according to the treatment beam’s position. Throughout the delivery of the radiation beam, you will hear a buzzing noise coming from the LINAC, but you will not be able to feel, hear, see, or smell the radiation. To ensure the treatment is precisely targeted to the tumour, it is crucial for you to stay still and breathe normally. Once the treatment is done, the Radiation Therapist will re-enter the treatment room to accompany you out.