When it comes to treating cancer with radiation, many patients are concerned about the long-term effects the treatment will have on their heart. For cancers near this vital organ, traditional x-ray radiation can cause several cardiac health issues, including heart attacks, heart failure, and arrhythmias.1
Heart radiation from cancer treatment is especially worrisome for breast, lung, and esophageal cancer patients. If any part of the heart is exposed to radiation, the risk of heart disease is increased. Often, these cardiac side effects don’t appear until several years after the cancer treatment.
In this article, we’ll look at each of those cancers and identify the risk associated with radiation, as well as how proton therapy cancer treatment can help alleviate some of the concerns.
Breast cancer treatment and heart radiation
Breast cancer patients have several treatment options, including surgery, chemotherapy, and radiation. These different methods are often used in conjunction with one another. For instance, a patient may choose to have surgery first to remove most of the cancer, then follow that up with radiation to ensure all cancer cells are destroyed.
When radiation therapy is part of the treatment plan, patients must consider their heart health. This is especially important for left-sided breast cancer, in which the cancer is close to critical structures like the heart, LAD (left anterior descending artery), and lungs.
With traditional x-ray radiation, physicians are not able to control the depth of the radiation. In other words, it will pass through the body entirely. Traditional radiation will destroy the cancer cells, but it will also enter the chest wall and expose anything in its path to harmful x-rays.
In fact, a study published in the New England Journal of Medicine confirmed the dangers traditional radiation poses to the heart. Researchers found the more radiation a patient’s heart received, the higher their risk of heart disease was later in life.2
That’s where proton therapy can help. Proton therapy is a more precise form of radiation therapy. It is just as effective at killing cancer cells and has remarkable advantages when it comes to lowering the risk of radiation side effects.
Protons have distinct characteristics that allow physicians to precisely target the tumor. Most importantly, they can also control the depth of the radiation beam. This means the protons will reach their target, destroy the cancer cells, then stop before entering the chest wall. Those vital organs and critical structures in the chest are spared from unnecessary radiation.
As a result, there is a lower risk of damage to the heart, which results in fewer long-term cardiac side effects.
Lung cancer treatment
Lung cancer patients have similar concerns about radiation therapy due to the lungs’ proximity to the heart. Just like with breast cancer, it is common for a lung cancer treatment plan to include multiple modalities, such as chemotherapy and radiation.
However, with traditional radiation, the heart is at risk of unnecessary radiation exposure, increasing the chances of long-term cardiac side effects.
A study from Penn Medicine suggests that proton therapy can help. Researchers looked at 200 lung cancer patients, some of whom underwent traditional x-ray radiation, while others chose proton therapy. They found that fewer proton therapy patients experienced mini-strokes and heart attacks compared to the traditional radiation group.
In addition to these long-term benefits, proton therapy also has short-term benefits for lung cancer treatment. Traditional radiation patients often experience side effects like nausea, shortness of breath, fatigue, or significant weight loss. However, proton therapy has been shown to nearly eliminate these ailments, resulting in a better recovery experience.
Researchers have compared the effects of radiation therapy on a patient’s lungs and esophagus. For lung cancer patients who received proton therapy, the rates of pneumonitis and esophagitis (inflammation of the lungs and esophagus) are significantly lower compared to patients treated with traditional radiation.
Esophageal cancer treatment
Esophageal cancer treatment also typically combines different modalities, and radiation therapy is often an important part of the plan. However, clinical studies have shown that the use of radiation therapy increases the risk of death related to heart disease.
A study published in the Journal of Gastrointestinal Oncology evaluated more than 40,000 patients who underwent esophageal cancer treatment. Researchers found that for patients receiving radiation therapy, death from heart disease occurred at 1.45 times the rate of those who didn’t receive it.3
The esophagus is located very close to the heart, making heart radiation from cancer treatment a serious concern. Proton therapy can help mitigate those concerns because of its ability to precisely target the tumor and limit exposure to the surrounding area.
A revolutionary form of proton therapy is called pencil beam scanning (PBS). This allows the proton radiation to conform to the shape and size of the targeted tumor, further reducing the risk of radiation exposure to the heart, as well as other critical organs and structures like the lungs and spinal cord.
The benefits of proton therapy lower the risk of short and long-term side effects for esophageal cancer patients. In fact, research suggests that using proton therapy in conjunction with surgery resulted in fewer post-surgery complications and shorter hospital stays.4
Sources & Studies:
- Harvard Heart Letter: Cancer treatments may harm the heart. Harvard Health Publishing, Harvard Medical School. 2012 Aug.
- Darby S, et al. Risk of ischemic heart disease in women after radiotherapy for breast cancer. N Engl J Med. 368;11.
- Frandsen J, et al. Increased risk of death due to heart disease after radiotherapy for esophageal cancer. J Gastrointest Oncol. 2015;6(5):516-523.
- Simone CB, et al. Clinical outcomes and toxicities of proton radiotherapy for gastrointestinal neoplasm: a systematic review. J Gastrointest Oncol. 2016 Aug;7(4):644-64.