Radiation Therapy 101

There is a lot of information on radiation therapy online.  The process of delivering radiation isn’t exactly the same between facilities however it’s similar.  In this installment we will look into radiation therapy generically to provide a general overview.

Methods For Treatment

There are a number of ways to treat cancer with radiation; the method used depends on the nature and position of your cancer.  The most prevalent method of radiation is known as external beam therapy.  This is often done using a linear accelerator from the outside of the body directing radiation to the tumor.

Radiation therapy is known to affect both cancerous and normal cells.  Radiation has a greater effect on cancerous cells.  Treatment is given at the highest dose possible, within a safe limit, to kill cancerous cells without causing damage to normal, healthy cells.  If the goal is to reduce the size of the tumor in order to relieve symptoms or to shrink the tumor for surgery, low dosages are often used.

Radiation Professionals

Radiation therapy is planned out by a specialist cancer doctor known as a radiation oncologist.  Then radiation is delivered by a radiation therapist.  A team of specialists including nurses, health care assistants, counselors, and dieticians will work together to ensure the best possible outcome for your treatment.

There are many benefits included in how radiation treatment is planned.  Each patient has a unique treatment plan that is designed to meet each patient’s particular need.  During the initial visit a course of treatment will be planned.  This is done using simulators, x-rays, and scans to pinpoint the tumor.  The skin will be marked to define the treatment area. 

Life With Treatments

Most individuals receiving radiation therapy will not need to stay overnight in a hospital after receiving radiation.  Therapy is done on an outpatient need unless your radiation oncologist determines that treatment would be more effective if done while admitted.

Patients are allowed to continue life as normal during their radiation treatment.  It should not cause too much interruption to your day, in fact it should be looked at as another daily routine activity.  Radiation is given using a linear accelerator which works by delivering radiation from the outside through your skin.  Patients receiving treatment lay on a treatment couch and are asked to remain completely still.

Radiation oncologists will determine the length of treatment needed when first evaluating your situation.  The course of treatment can last anywhere from a week to six and can be performed on a weekly or daily basis.  This will depend on a number of factors including the area that is being treated, the aim of the treatment, and more. Each session of radiation varies depending on the machine used.  Most sessions last between five and fifteen minutes.

As an independent LINAC service company, Acceletronics is dedicated to delivering the best equipment performance and services for linear accelerators and CT scanners across all major brands and models, as well as new and refurbished LINAC systems for sale.  More information can be found online at https://www.acceletronics.com/.

A Sampling of Different LINAC Components and What They Do

A drive stand is a large part of a linear accelerator.  It is a cabinet in the shape of a rectangle that is attached to the floor within the treatment room.  The horizontal axis bearings that the gantry rotates on are positioned within the drive stand.
Components Within the Drive Stand

• Klystron or Magnetron
• RF Waveguide
• Circulator
• Cooling Water System

Klystron:

A Klystron is responsible for the microwave power that is used to accelerator the electrons.  This process occurs through intensification of present RF (Radio Frequency) electromagnetic waves.  The basic description of the operation of a Klystron is that it is a RF amplifier. A Klystron is often chosen for LINAC needing larger amounts of electron energy.

Magnetron:

A magnetron can be used in place of a Klystron.  A Magnetron is an electron tube that is responsible for providing the microwave power to accelerator electrons. A Magnetron is often chosen for LINAC needing smaller amounts of electron energy such as 4 MeV to 6 MeV LINAC.

RF Waveguide:

The structure in which the microwave powered RF electromagnetic waves are accelerated from the Klystron or Magnetron.

Circulator:

The circulator connects the Klystron or Magnetron to the RF Waveguide.

Cooling Water System:

A cooling system is in place to prevent overheating.  It creates a stable temperature environment within the Drive Stand and Gantry.

A gantry rotates three hundred and sixty degrees around a single point.  It works by directing the radiation beam from the LINAC to the tumor without moving the patient. 
Components Within the Gantry

• Electron Gun
• Accelerator Structure
• Treatment Head

Treatment Head:

The treatment head of a linear accelerator encompass the components that shape and monitor the radiation beam.  These components include bending magnet, collimator, ion chambers, tray slots, wedges, blocks, and compensators.

Modulator Cabinet:

The modulator cabinet is the loudest components of a linear accelerator.  This component is located within the radiation treatment room.  The modulator cabinet includes a fan control, auxiliary power distribution system, and a primary power distribution system.  The fan control is used to cool off the power distribution systems.  The power distribution systems include the emergency off button to shut down the power to the LINAC.

Bending Magnet:

A bending magnet is a component of a LINAC that changes the direction of the beam down towards the patient.  It bends the beam towards the target and produces different paths for the beam for different energy needs. 

As an independent LINAC service company, Acceletronics is dedicated to delivering the best equipment performance and services for linear accelerators and CT scanners across all major brands and models, as well as new and refurbished LINAC systems for sale.  More information can be found online at https://www.acceletronics.com/.

Exploring Radiation Therapy Treatments Part 2

As promised in our last blog post today we will dive into the concept of radiation therapy.  In our last installment we discussed linear accelerators and how the radiation beam is produced and delivered.  If you are unfamiliar with LINAC and how radiation is created and delivered look back at our previous blog post before continuing.  

Radiation Therapy

The treatment of cancer with radiation is known as radiation therapy. Depending on the type of cancer you have been diagnosed with will depend on the way radiation therapy is delivered to your tumor(s).  The most common method of radiation therapy is external beam therapy.  This involves delivery of radiation to the cancerous tumors from outside of the body.  The radiation is delivered directly to the tumor.  A LINAC allows the radiation beam to be shaped in the same shape as the cancerous tumor.  Another option of radiation therapy is internal radiation therapy.  This treatment involves implanting radiation directly onto the cancerous tumor. The nature of the cancer being treated will determine the type of radiation therapy delivered.

How It Works

Radiation therapy does not distinguish between healthy and cancerous cells although the effect is greater on cancerous cells. The highest dose of radiation possible is delivered to the cancerous tumor in the attempt to kill, break down, and shrink tumor. Smaller doses of radiation can be delivered when palliative care is the goal.  The goal of palliative care is to relive symptoms of cancer by shrinking the size of the tumor.  Palliative care is focused on increasing the quality of life left for a patient and their family.

Who Performs Radiation Therapy

A radiotherapist/radiation oncologist is what we refer to as a physician specializing in the treatment of cancer. This individual is the person that will plan and oversee your treatment from beginning until the end of treatment.  Radiation is delivered by a professional known as a radiation specialist.  A team of professionals will work with your specialists to ensure you are receiving the best care possible.  Some of the members of this team include: nurses, health care assistants, counselors, and dietitians.

Treatment Plan

Each course of radiation therapy is uniquely designed for the patient that is being treated.  A preliminary appointment will be scheduled in which you will discuss your course of treatment.  This plan is created by your radiation oncologist and radiation therapist using all the scans and x-rays that have been taken of your cancerous tumor.  The skin is colored in to define the location of the tumor and where the treatment will be delivered.  If radiation is being delivered to your head a head shell will be created for you that allows for the exact placement of treatment to be marked on the shell vs on your skin.  Treating cancer in the mouth or throat will require a dental assessment to determine if dental treatment is needed before radiation can be delivered.

Inpatient vs Outpatient

Patients that can go to and from the hospital easily will most likely be allowed to have outpatient radiation therapy.  Your radiation oncologist will tell you if they would prefer your treatment to be inpatient but overall most treatment is done on an outpatient basis. 

Additional Tests/Scans During Treatment

Over the course of radiation therapy, patients will be asked to have an occasional blood draw or urinalysis completed.  X-rays and other scans can also be required to determine if the radiation is working and if the placement of the treatment is correct based on the shrinking or break down of the tumor.

During Treatment What Should I Avoid

Radiation therapy should be considered an interruption to normal life.  Your daily life can be continued as normal if you are feeling emotionally and physically able.

Things to Keep in Mind During Radiation Therapy

Delivery – External radiation therapy is delivered using a machine known as a linear accelerator which was described in detail in our last installment.  For radiation to be delivered, you as the patient will be asked to lie on a couch under the LINAC and will need to remain still until the treatment is over.

Pain – Radiation therapy is painless.  The radiation can not be felt or seen during delivery.

Radioactivity – Patients always wonder if they will be radioactive after receiving radiation therapy.  You can rest assured that you will not be radioactive, there is no possible way for this to occur.

Duration – The duration of treatment will be decided by your radiation oncologist.  A course of radiation can be between one treatment to one every day, for one week to six weeks.  This will all depend on the type of cancer being treated, the dose of radiation needed, the part of the body being treated, and the aim at therapy whether it is therapeutic or palliative.

Length of Sessions - The length of each radiation session varies between machines and what is planned in your specific treatment plan.  Some LINAC operate at a faster rate than others.  Some cancerous tumors respond better to longer treatment sessions with smaller doses of radiation.  On average patients can expect that their sessions will last between five and fifteen minutes.

Do’s and Don’ts During Treatment

Do’s

• Make sure to drink plenty of fluids
• Eat a regular, balanced diet
• Shower regularly

Don’ts

• Avoid alcohol, spicy food, or extreme hot and cold food
• Avoid exposure to sunlight on the treated area
• Avoid applying creams and deodorant to the treated area

Radiation treatment is localized.  Side effects depend on the location of treatment on the body.  We should note that side effects are rare however the following can occur:

• Nausea
• Diarrhea
• Frequent Urination
• Sore Throat
• Localized Hair Loss

Work

Patients can keep on working as usual as long as they are feeling able and their radiation oncologists agree.  If your oncologist suggests time off for rest, it is best to listen to them and avoid work.

Once Treatment Is Finished

If you do have any of the above side effects, it can be assumed that they will end after a week or two.  The full benefits of radiation can usually be reached after a few weeks.  You will follow up with your specialists after four to six weeks of your final radiation treatment.  This will all be determined by your radiation therapist.

As an independent LINAC service company, Acceletronics is dedicated to delivering the best equipment performance and services for linear accelerators and CT scanners across all major brands and models, as well as new and refurbished LINAC systems for sale.  More information can be found online at https://www.acceletronics.com/.