Parts: Linear Accelerator

 

 

Tips for buying Linear Accelerator Parts

A linear accelerator (LINAC) is the device most commonly used for external beam radiation treatments for patients with cancer. The linear accelerator can also be used in stereotactic radiosurgery on targets within the brain. The linear accelerator is used to treat all parts/organs of the body. It delivers a uniform dose of high-energy x-ray or electrons to the region of the patient’s tumor. This radiation can destroy the cancer cells while sparing the surrounding normal tissue. LINAC can be used to treat all cancerous areas of the body and is used in not only external beam radiation therapy, but also for Stereotactic Radiosurgery and Stereotactic Body Radiotherapy.

Linear accelerators are comprised of a number of integrated and interdependent linear accelerator parts, using a radar type R.F Generator and an accelerating wave guide to create x-ray or electron beams for the radiotherapy treatment.  There are many other linear accelerator parts which support the function of the linear accelerator system.

LINAC machines may be dedicated or non-dedicated. Dedicated linear accelerators have the additional equipment to perform higher level treatments, such as the radiation couch, which is the preferred method. Non-Dedicated LINAC machines may be used for conventional radiation therapy, and after adding the attachment, can be used for higher level treatments. Non-dedicated linear accelerators are unable to attain the same degree of precision and accuracy that dedicated machines have. All of the special attachments are unique linear accelerator parts that cannot be used on other equipment.

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 of the checks match, the machine will turn on to deliver the treatment.

The linear accelerator uses microwave technology (similar to that used for radar) to accelerate electrons in a linear accelerator part called the “wave guide”, which allows these electrons to collide with a heavy metal target. As a result of the collisions, high-energy x-rays are produced from the target. The high-energy x-rays are directed at the patient’s tumor and shaped as they exit the machine to conform to the shape of the abnormal growth.  The beam may be shaped either by blocks that are placed in the head of the machine or by a multileaf collimator linear accelerator part that is incorporated into the head of the machine. The beam comes out of a linear accelerator part 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. The treatment couch can move in many directions including up, down, right, left, in and out. Radiation can be delivered to the tumor from any angle by rotating the gantry linear accelerator part and moving the treatment couch.

Electrons are accelerated to kinetic energies from 4 – 25 MeV using microwave RF Fields, in special evacuated accelerating wave guides.

Linear accelerators are usually mounted isocentrically and their operational systems are distributed between the 5 major linear accelerator parts as follows:

• Gantry.                            
• Gantry stand and support.                    
• Pulsed modulator cabinet.                    
• Patient’s support assembly – treatment couch.        
• Control consol.                        

The main beam forming components of a modern medical LINAC are grouped into the following linear accelerator parts:

• Injection system – the electron gun.            
• Radiofrequency power generator system.        
• Accelerating wave guide.                    
• Auxiliary system.                    
• Beam transport system.                
• Beam collimation and monitoring system .    

Linear accelerators have evolved to the current design through five generations and is now the most widely used radiation source in modern radiotherapy, with thousands of units in clinical practice around the world today.