Proton therapy which is also termed as proton beam therapy, is a type of radiation therapy which uses high energy beams for treating various types of cancer. This treatment delivers external beams of radiation directly to the cancerous tissues.
The procedure is generally performed in outpatient treatment centers, where they use a machine known as cyclotron or synchrotron. Since these machines are quite large and expensive, only a limited number of centers offer this treatment. Studies have shown that proton therapy causes fewer side effects, compared to other traditional radiation therapies, as doctors are able to better control where exactly the proton beams will deposit their energy.
Proton therapy is also used quite often in combination with other cancer treatments such as chemotherapy and surgery, though in some cases, proton therapy might be the only treatment recommended by your doctor.
Proton therapy is a preferred treatment method for cancer as well as some noncancerous tumors. Sometimes, it is the only treatment required for your condition, though in other cases it is used in conjunction with other treatments such as surgery and chemotherapy.
This procedure can be used for treating:
- Brain tumors
- Esophageal cancer
- Breast cancer
- Lung cancer
- Cancer in children
- Eye melanoma
- Head and neck cancers
- Liver cancer
- Pituitary gland tumors
- Prostate cancer
- Tumors affecting your spine
- Tumors in the base of your skull
Before you undergo this procedure, your health care team will be guiding you through a planning process for ensuring that the proton beam reaches the precise spot in the body where it is required.
The planning typically includes:
Determining the best position for you during treatment- During radiation simulation, the radiation therapy team will work so that they are able to find a comfortable position for you during the treatment. It’s imperative that you lie still during treatment; therefore, it is quite important to find a comfortable position. To do this, first you will be positioned on the table to be used during your treatment. Cushions and restraints are used for placing you in the correct position and for helping you hold still. The team will mark the area of your body that will be receiving the radiation. Depending on your situation, you might receive temporary marking with a marker or you may also receive permanent tattoos.
Planning the path of the protons with imaging tests- Your team might require you to undergo magnetic resonance imaging (MRI) or computerized tomography (CT) scans to determine the area of your body to be treated and how best to reach it using the proton beams.
Typically, you will need to undergo proton therapy for five days a week for several weeks. Depending on your condition, in some cases, however, you may need only one or a few treatments. The actual treatment should take only a minute or so. However, you need to spend over 30 minutes generally preparing for each treatment session.
You might also need to undergo weekly CT scans to see if the dose you are receiving needs to be recalculated based on changes in weight or tumor size and shape depending on your situation.
During the procedure, first, you are positioned on a table. To hold your body still, cushions and restrains will be used. Then you will undergo an imaging test such as an X-ray or CT scan, to ensure that your body is in the same precise position before each treatment.
Then the team will leave the room and go to an area from where they will be able to monitor you.
What you experience next will depend on the type of proton therapy machine which your treatment team is using:
- If you’re undergoing the treatment with a machine called a gantry, you will be placed on a table that is slid slowly into the circular opening of the machine. The machine then rotates around you to direct the proton beams at the precise points.
- If you’re undergoing proton therapy with a fixed-beam machine, the table where you are positioned on will move while the proton therapy machine will remain still. Your table’s movement during the treatment is controlled remotely by your radiation therapy team. How often your table will move during the treatment can depend on your situation.
You will not be able to feel the radiation during your treatment.
After proton therapy
Once your treatment session is over, you can resume your daily activities. You will not be radioactive or give off any radiation.
It is to be noted that the side effects of radiation usually develop over time. Though you may experience few side effects at the beginning, after multiple treatments you will be experiencing fatigue, which can make it feel like your usual activities are requiring more energy or that you have very little energy during your everyday tasks. You might notice sunburn-like skin redness as well in the area where the proton beams are directed.
Your doctor can recommend periodic imaging tests during and after your proton therapy. This is to determine how well your cancer is responding to the treatment. How often you will need to undergo these scans depends on your situation.
Proton therapy can cause multiple side effects, especially when the energy from the proton beam damages any of your healthy tissues. Since doctors are able to better control where the energy is released during the treatment, the treatment is believed to have fewer side effects as compared to traditional radiation therapy.
The side effects that you will go through will depend on which part of your body is being treated as well as the dose that you receive.
Generally, the common side effects of this treatment include:
- Eating and digestion problems
- Skin redness around the part of the body being treated
- Hair loss around the part of the body being treated
- Soreness around the part of the body being treated