£6m for state of the art treatment equipment
Watch the video of the new IMAT, developed by Elekta
IMAT VideoThe New Oncology Wing at St James's Hospital is one of the biggest purpose-built cancer centre in western Europe. It is designed to improve the outcomes of cancer treatment for our cancer patients in Yorkshire.
The pace of change in cancer care, treatment & scientific improvement has meant that we can now apply those changes directly to patient care much more quickly than in the past.
New drugs are targeted at a molecular level. New imaging techniques and a better understanding of the biology of cancer cells means that existing treatments can be used with much greater impact. This can bring about higher cure rates & even where treatment is palliative in nature, patients can enjoy a longer & better quality of life.
Linear Accelerator
A linear accelerator (LINAC) is the device most commonly used for external beam radiation treatments for patients with cancer. The linear accelerator can al so be used in stereotactic radiosurgery similar to that achieved using the gamma knife on targets within the brain. The linear accelerator can also be used to treat areas outside of the brain. It delivers a uniform dose of high-energy x-ray to the region of the patient's tumour. These x-rays can destroy the cancer cells while sparing the surrounding normal tissue.
A linear accelerator is also used for Intensity-Modulated Radiation Therapy (IMRT).
How it works
The linear accelerator uses microwave technology (similar to that used for radar) to accelerate electrons in a part of the accelerator called the "wave guide", then allows these electrons to collide with a heavy metal target. As a result of the collisions, high-energy x-rays are scattered from the target. A portion of these x-rays is collected and then shaped to form a beam that matches the patient's tumour. The beam comes out of a part of the accelerator called a gantry, which rotates around the patient. The patient lies on a moveable treatment couch and lasers are used to make sure the patient is in the proper position. Radiation can be delivered to the tumour from any angle by rotating the gantry and moving the treatment couch.
The patient's consultant oncologist prescribes the appropriate treatment volume and dosage. The medical physicist and the dosimetrist determine how to deliver the prescribed dose and calculate the amount of time it will take the accelerator to deliver that dose. Radiation therapists operate the linear accelerator and give patients their daily radiation treatments.
Safety
Patient safety is very important. During treatment the radiation therapist continuously watches the patient through a closed-circuit television monitor. There is also a microphone in the treatment room so that the patient can speak to the therapist if needed. Port films (x-rays taken with the treatment beam) are checked regularly to make sure that the beam position doesn't vary from the original plan.
The linear accelerator sits in a room with lead and concrete walls so that the high-energy x-rays do not escape. The radiation therapist must turn on the accelerator from outside the treatment room. Because the accelerator only gives off radiation when it is actually turned on, the risk of accidental exposure is extremely low. Indeed, pregnant women are allowed to operate linear accelerators.
Modern radiation machines have internal checking systems to provide further safety so that the machine will not turn on until all the treatment requirements prescribed by your physician are perfect. When all the checks match and are perfect, the machine will turn on to give your treatment.
Quality control of the linear accelerator is also very important. There are several systems built into the accelerator so that it won't deliver a higher dose than the radiation oncologist prescribed. Each morning before any patients are treated, the radiation therapist uses a piece of equipment called a "tracker" to make sure that the radiation intensity is uniform across the beam. In addition, the radiation physicist makes more detailed weekly and monthly checks of the accelerator beam.
We have reached a very exciting time in radiotherapy as we look forward to our move to the Yorkshire Cancer Centre.
Intensity modulated radiotherapy is a highly technical new approach to the delivery of radiotherapy where, under sophisticated computer control, the shapes of the beams & the radiation dose intensity are varied across the tumour to shape in three dimensions to the complex shape of the tumour volume.
IMAT (Intensity Modulated Arc Therapy) £6m - out target to provide two machines
A British company Elekta, has recently developed a highly technical process called IMAT (intensity modulated arc therapy) where besides the shape of the beam and the radiation dose intensity, the direction of the beam is changed throughout treatment by arcing the machine around the patient. Our Medical Physicists are looking for systems which give us image guided radiotherapy, where an imaging system is mounted on the treatment machine so that they can image at the same time. That allows the clinician to modify treatments on a daily basis - to adapt the treatment to suit the position of the patient on any given day.
The benefits of the IMAT system to cancer patients are enormous - higher dosage to the cancerous tumour whilst avoiding healthy tissue - resulting in less side effects and positive outcomes.
