Many people with breast cancer will have radiation therapy as part of their treatment. A benefit of radiation therapy is that it can destroy cancer cells within a specific area. But in the process, it can affect nearby healthy tissue.
Proton therapy is a type of external beam radiation therapy that can lower the risk of damage to surrounding tissue. If you have breast cancer, this can help prevent radiation damage to your heart and lungs.
In this article, we’ll discuss proton therapy and when it’s used as well as answer some FAQs about proton therapy for breast cancer.
Radiation therapy uses high-intensity energy beams to destroy cancer cells.
In traditional radiation therapy, also known as photon therapy, the energy comes from X-rays. These beams pass through the tumor and continue on, which can sometimes harm nearby healthy tissues and organs. In breast cancer treatment, this can damage heart or lung tissue.
More precise targeting may help reduce tissue damage
Proton therapy allows more precise targeting. Since it uses charged particles called protons instead of X-rays, doctors can choose a specific stopping point. They can concentrate the energy beams directly on the tumor without letting it pass through to the underlying tissue.
As a result, proton therapy may reduce the risk of damage to the heart and lungs, according to
Proton therapy may be used to treat breast cancer that is:
- stage 1, 2, and 3
- estrogen receptor-positive or negative
- progesterone receptor-positive or negative
- HER2-positive or negative
- ductal carcinoma in situ
- invasive ductal carcinoma
- invasive lobular carcinoma
Traditional radiation vs. proton therapy
Both traditional and proton radiation therapy kill cancer cells. The difference is in precision. Traditional radiation therapy allows the beam to extend beyond the tumor, which can damage healthy tissue and organs.
Proton therapy stops where the tumor stops. Since radiation does not exit the tumor, there’s less potential for damage to healthy tissue, including the heart and lungs.
Factors that may increase radiation to the heart include:
- having tumors on the left side
- having tumors in the inner quadrant
- having a mastectomy
- receiving radiation therapy to regional lymph nodes
Your doctor might also recommend proton therapy if you’re at high risk of heart disease.
Treatment typically involves multiple therapies
Breast cancer treatment usually involves multiple therapies. These may include:
- a mastectomy or lumpectomy
- radiation therapy
- targeted therapy
- hormone therapy
- biologic therapy
Factors that influence your treatment plan
Your doctor will present a treatment plan based on factors such as your:
- age and overall health
- stage at diagnosis
- specific type of breast cancer
- tumor grade
- previous cancer treatments if it is a recurrence
A 2018 study followed 42 people who had proton therapy after a mastectomy for non-metastatic breast cancer. After almost 3 years of median follow-up, the overall survival rate was 97.2 percent. This is equivalent to outcomes with traditional radiation therapy.
A phase 2 study published in 2019 found that proton therapy for breast cancer has a similar rate of disease control as traditional radiation therapy.
Larger long-term studies are still needed.
Getting proton therapy is very similar to getting traditional radiation therapy.
The outpatient procedure takes just a few minutes, but you’ll probably be in the procedure room for about 30 minutes. It’s usually administered five times a week for up to 6 weeks, the same as traditional radiation therapy.
Prior to starting, the radiation therapist will find the best position for treatment and mark your skin accordingly. These markings will guide all future treatments.
It’s an open machine, so you won’t feel closed in. Once you’re properly positioned, the therapist will go to the control room to deliver the treatment. You’ll need to remain perfectly still, but the treatment is painless.
The therapist can communicate with you through an intercom and let you know when it’s fine to move. You’ll be able to leave as soon as it’s over.
Side effects of proton therapy are similar to those of traditional radiation. These may include:
- skin tenderness
- redness that resembles a sunburn
Research from 2018 suggests that proton therapy has a favorable toxicity profile.
Within 90 days of starting treatment, 12 percent in the proton group had a side effect severe enough to need hospitalization. That compares to 28 percent in the traditional radiation group.
But it will take longer follow-up times and clinical trials to fully investigate long-term adverse effects.
Is proton therapy more effective than traditional radiation therapy?
Both types of radiation therapy are effective.
Is proton therapy safer than traditional radiation therapy?
Since proton beams do not continue past the tumor site, it may lower the risk of radiation damage to healthy tissues. If you have breast cancer, that can mean reducing the chances of damage to the heart and lungs.
This may be especially important if you’re at high risk of heart disease. More long-term studies of traditional versus proton radiation therapy are needed.
Is proton therapy used for other types of cancer?
Yes, proton therapy is used to treat a variety of other cancers. These include:
- prostate cancer
- brain cancer
- lung cancer
- liver cancer
- esophagus cancer
- many pediatric cancers
Is proton therapy covered by health insurance?
Medicare and some other insurance providers cover all or a portion of the cost of proton therapy. Not all do, though. It’s important to check with your insurance provider before starting therapy so that you’re not caught off guard.
Your doctor’s office can help determine whether your policy covers proton therapy.
Where can you get proton therapy?
Many major hospitals and cancer treatment centers now offer proton therapy, though it may be difficult to find in some areas. Your oncology team can let you know if there’s a location near you.
Proton therapy is an advanced type of external beam radiation therapy. It delivers high-dose radiation directly to cancer cells.
It’s more precise than traditional radiation therapy, so it’s less likely to harm nearby tissues and organs. When treating breast cancer, proton therapy may lower the risk of heart or lung damage. Side effects can include skin tenderness, redness, and tiredness.
The experience is similar to getting traditional radiation therapy and is generally just one part of your overall treatment plan.
If your doctor recommends radiation treatment for breast cancer, ask if proton therapy is a good option for you.