Skip to 0 minutes and 6 seconds Entering the treatment room, you will walk down a maze. When you enter the room, you will see the linear accelerator. You will also see the laser system. The lasers are located on the walls of the treatment room and also on the ceiling. These lasers are used to position you for treatment. When positioning the lasers, the radiation therapists with dim the room lights. There is a treatment couch that you will lie on and be positioned down for treatment. There are various components to the linear accelerator. The gantry is the main body of the linear accelerator. It can move 360 degrees around the treatment couch, and is noisy when moving.
Skip to 0 minutes and 49 seconds The radiation therapist can move the gantry when they are both in the treatment room, and also outside the treatment room. In order to facilitate the movement of the gantry the treatment couch is deliberately quite narrow.
Skip to 1 minute and 3 seconds The circular part of the linear accelerator at the head of the gantry is called the collimator. This too can move 360 degrees.
Skip to 1 minute and 16 seconds From the head of the gantry, the light field size can be seen. The light field size shows the radiation therapist, or RTTs, the size, shape, and orientation of the treatment beam. From here, the radiation therapist can also use a measurement tool called the optical distance indicator, or ODI, to take various measurements. These measurements are compared to your personalised treatment plan to ensure that the treatment is correctly delivered. The radiation therapist can move the treatment couch in many different directions to position you correctly for treatment. This can be up, down, vertical, side-to-side, lateral, top-to-bottom, longitudinal. And the treatment couch can also be rotated. The radiation therapist also take images of your treatment regularly throughout your treatment course.
Skip to 2 minutes and 15 seconds A panel will appear to capture these images. These images are only used to ensure your position is as planned. These images do not tell the radiation therapist how the treatment is working.
Skip to 2 minutes and 29 seconds You will also notice other pieces of equipment in the treatment room. These can be devices that are used to position and immobilise you for treatment. Here is an example of an immobilisation system for brain tumours.
Skip to 2 minutes and 44 seconds This system is used for mobilising patients receiving radiation therapy to the chest or thoracic region, such as breast, lung, or esophageal cancers. This device can be individualised to different patient shapes and sizes. Other devices that can be added to the head of the gantry are known as accessory equipment. This one is added if electron therapy is to be delivered. You will hear the radiation therapist calling out a series of numbers to one another during positioning and before they leave the treatment room. This is part of quality control, verifying the parameters of your personalised treatment plan.
The treatment room
In this video, Claire is using a piece of technology called VERT or Virtual Environment of a Radiotherapy Treatment Room, to show what a treatment room looks like.
This technology is often used to educate radiation therapy students here in Trinity College.
Some of the terms used in the video include:
- Radiation therapy is generated by a large machine called a linear accelerator which delivers high energy x-rays or electron beams to a patient’s tumour.
- All patients being treated with radiation therapy must lie on a narrow bed which is known as the treatment couch. Most modern treatment couches are made from a carbon material which allows photon energies to travel through the bed and treat the patient i.e. they have a low attenuation of the beam.
- The gantry is the main body of the linear accelerator. It can move 360 degrees around the treatment couch and is noisy when moving. The radiation therapists can move the gantry when they are both in the treatment room and also outside the treatment room. In order to facilitate the movement of the gantry, the treatment couch is deliberately quite narrow.
- The circular part of the linear accelerator at the head of the gantry is called the collimator. This too can move 360 degrees.
Light field size
- The light field shows the radiation therapists (RTTs) the size, shape and orientation of the treatment beam.
Optical Distance Indicator (ODI)
- This a measurement tool that can be used daily to take various measurements. These measurements are compared to your personalised treatment plan to ensure that the treatment is correctly delivered.
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