Cancer Still Sucks, But Proton Therapy Is Making A Huge Positive Difference In Many Patients' Lives

Cancer is — undeniably and profoundly — scary. Over 38 percent of adults will be diagnosed with some type of cancer over the course of their lives, along with numerous children. Each year, around 14 million new cases of cancer are identified, and a shocking 9.6 million people lose their lives to cancer worldwide. Lung, colorectal, stomach, liver, and breast cancers are the most deadly cancers.

For those people who are personally affected by cancer, because they or someone they care about was diagnosed with it, it’s easy to lose hope. But though cancer is a leading cause of death worldwide, there’s also good news — with the right action, lots of cases can be prevented and many more cured.

What is proton therapy for cancer?

Proton therapy is a relatively new method to deliver curative radiation to treat cancer. Like conventional radiation therapy (also called radiotherapy), which uses high-energy X-rays and gamma radiation, proton therapy uses protons (positively-charged subatomic particles) to damage, and eventually kill, cancer cells.

Using a particle accelerator, the machine used during proton therapy first extracts and collects protons from hydrogen, which is transformed from its natural gas state to a plasma state. The large magnets then “collect” and accelerate those protons to nearly 70 percent of the speed of light so they can gain enough energy, and finally leave the accelerator in the form of a proton beam. The proton beams are then navigated to the "gantry" (a robotic chair where the patient receives treatment), and finally to the patient — or, more precisely, the cancer itself.

When the protons travel through the body, they lose energy, and therewith also speed. And when the protons are slowed down to a specific degree, the energy they give to the surrounding molecules greatly increases and the protons stop moving. The time protons spend near the cancer cells is enough for the protons to give all of their remaining energy to the molecules that make up these cancer cells, including their DNA. This complex scientific process disrupts molecules' normal function, killing cancer cells.

The main types of proton therapy are:

• Passively scattered proton therapy, where a narrow beam is scattered to a larger area, resulting in higher unwanted radiation doses.
• Uniform scattering, which uses a broad beam to cover the treatment area.
• Pencil beam scanning, which is extremely precise but demands longer treatments. This technique is so targeted that even breathing and bowel movements can send the beam outside the treatment area. Although relatively new, this type of scanning has the greatest potential in the future of proton therapy.

What are the main benefits of proton therapy?

The fact that children are especially vulnerable to the effects of radiation, since they’re still growing, makes proton therapy uniquely suitable for the treatment of many pediatric cancers. Proton therapy can also make a big difference where tumors have taken hold in parts of the body that contain important and sensitive organs — breast cancer treatment may, for instance, require radiation to be delivered close to the heart. 

The precision of the radiation used in proton therapy greatly reduces the risk of secondary cancer as a result of the initial treatment, and research has shown proton therapy to have fewer, less intense, and less long-lasting side effects than conventional radiotherapy, so patients generally tolerate proton therapy very well.

Even with this innovative technology, going through cancer treatment won’t be easy — but patients who have been deemed suitable candidates for proton therapy can take comfort in knowing that they’re receiving the best care science has to offer, from a dedicated medical team who will work hard to meet their needs. “It is really exciting to be involved in all technological and clinical developments,” Dr Brouwer told SteadyHealth. 

What kinds of cancers can be treated with proton therapy?

Proton therapy can currently be used to treat many localized solid tumors that haven't metastasized, and the UMC Groningen highlights breast cancer, cancers of the neck and head, and brain tumors as cancers that are often better treated using this method. Not everyone diagnosed with cancer benefits from proton therapy, and patients who have access to a proton therapy center will have to ask their treating medical teams whether they would make good candidates.

If proton therapy is so awesome, why can’t everyone have it? 

Proton therapy can be up twice as expensive as conventional X-ray radiation. This cancer treatment is complex and still not widely available — in the United States, for instance, only 29 regional proton therapy centers are currently able to offer the treatment, and the situation is similar in most of the rest of the world. Dr Brouwer also adds that not every proton therapy center is the same, since the methods are improved constantly with new research — “high quality photon therapy can be better than proton therapy in older treatment centers.”

In the Netherlands, Dr Brouwer says, every cancer patients who would benefit from receiving proton therapy “can be treated in Groningen for the moment”, at the revolutionary new Proton Therapy Center that opened its doors in 2018.

Before choosing the best course of action, both photon and proton radiation treatment plans will be designed for each patient, after which their medical team chooses the option that is most suitable for the individual. “In Holland we follow the ‘model-based approach’,” Dr Brouwer shares, “and compare photon and proton plans on Normal tissue complication probability (NTCP).”

Patients diagnosed with brain cancer, chondrosarcoma (a type of bone cancer), and pediatric patients are the most obvious candidates for proton therapy, she explains. 

What can patients expect from proton therapy?

At UMC Groningen’s Proton Therapy Center, patients will meet with their radiation-oncologists before they start their treatment. This gives the medical team the chance to make sure they have all the information they need about the patient’s medical history and personal needs, and that the patient knows what they can expect.

Patients will learn about the number of proton therapy sessions they need, for instance, and what side effects are common. Patients receiving proton therapy for cancers of the head and neck may experience fatigue, a dry mouth, and difficulty swallowing, for instance. The skin around the treated area is also likely to become red and itchy.

Patients receiving treatment at Groningen's Proton Therapy Center are connected with a “patient service”, a dedicated team of people who help patients receiving cancer treatment navigate the therapeutic process, answering their questions every step of the way. 

After that, imaging techniques are used to pinpoint the exact region that will be treated, and where necessary, a mask will be made to keep the patient in the proper position during the radiation sessions. 

Once the treatment plan is complete, patients are ready to start their proton therapy sessions. The exact number of planned proton therapy sessions varies from case to case — patients might have anywhere between five and 39 treatment sessions — and individual treatments can last from 15 to 45 minutes.

How will proton therapy change in the future?

Dr Brouwer shares that UMC Groningen’s Proton Therapy Center “expects to publish the first results on head and neck cancer in the coming years”. Over the next decade, she says, “we will learn more on which patients and organs will benefit from proton therapy”. 

Proton beam therapy will be more widely available to cancer patients who would benefit from it in the future as more proton therapy centers open — and that will translate to better outcomes for many patients, especially children suffering from cancer.

Progress isn’t just possible, but already underway. A better future is indeed within reach.