A linear accelerator (LINAC) is a device, which functions by customizing high energy x-rays or electrons, so as to conform to a tumor’s shape, destroy cancer cells and spare surrounding normal tissue. This improvement incorporates a lot of built-in safety measures to ascertain that higher dose than prescribed will not be delivered. Besides, there are routine checks that are usually carried out on this equipment by a certified medical physicist to confirm its proper working.

When a patient is scheduled for radiation therapy via LINAC, a radiation oncologist will work in conjunction with both a radiation dosimetrist and a medical physicist to get a treatment plan develop for him or her. This treatment plan is usually double checked by a doctor prior to treatment in order to sustain quality assurance procedures.

What is a LINAC used for?

A linear accelerator (LINAC) is a device which is often used for the treatment of external beam radiation for cancer patients. All parts or organs of the body is indicated with the LINAC as it delivers high energy x-rays or electrons to the location of the tumor in the patient’s body. LINAC ensures treatment by destroying the cancer cells and spares the surrounding normal tissue. All body sites can be treated via LINAC, using conventional techniques and other therapies like Stereotactic Body Radio Therapy (SBRT), Volumetric Modulated Arc Therapy (VMAT), Intensity-Modulated Radiation Therapy (IMRT), Image Guided Radiation Therapy (IGRT) and Stereotactic

How LINAC systems work?

A linear accelerator employs micro wave technology for accelerating electrons in the wave guide a part of the accelerator. It achieves this by allowing collusion between these electrons and a heavy metal. The target is to produce high energy x-rays.

As the x-rays exit from the linear accelerator, they are made to conform to the shape of the patient’s tumor. The customized beam, which is incorporated into the head of the machine, is then directed to the tumor.

At this point, the patient is positioned on a moveable treatment couch while the beam diffuses from the gantry (a part of the linear accelerator) and it is being made to rotate round the patient. From any angle, the tumor can receive radiation when the gantry is rotated and the treatment couch is moved.

LINAC and Safety

There are several ways of ensuring a patient’s safety while using this equipment.  Prior to treating a patient, the radiation oncologist in conjunction with the radiation dosimetrist and medical physicist develop and approve a treatment plan.

Having double checked this treatment plan, treatments and quality assurance procedures are carried out to ensure that the treatment will be delivered as planned. It is highly essential to ensure quality assurance of the accelerator. It contains several built-in systems which ensure that it does not deliver a higher dose than the one prescribed.

As a safety measure, the radiation therapist inspects the machine every morning and ensures uniform radiation intensity across the beam. Besides, a more detailed and annual checks of the linear accelerator are carried out by the medical physicist.  The modern linear accelerators also have some internal checking systems which prevent the machine from being turned on until all prescribed treatment requirements are met.

As treatment continues, the patient is continuously observed by the radiation therapist via a closed- circuit television monitor. The patient will also be able to speak with the therapist if the need arises. In addition, pot films and cone beams are regularly inspected to prevent variation of the beam position from the original plan.

It is also crucial to ensure the safety of the staff that operates the linear accelerator. The linear accelerator is placed in a room reinforced with lead and concrete walls to shield the high-energy x-rays and ensures that the accelerator is turned on from outside the treatment room. In this case, accidental exposure risks are drastically low.

Acceletronics is an independent service company dedicated to delivering the best equipment performance and service reliability from Linear Accelerators and CT Scanners across all major brands and models. Learn more about Acceletronics and their selection of new and refurbished linear accelerators and CT scanners today at http://www.acceletronics.com.  To contact one of our LINAC experts call 610.524.3300.