fbpx Body Position During Radiation Matters for Large-Breasted Women
A woman lies down under a radiation machine.
A woman lies down under a radiation machine.

Body Position During Radiation Matters for Large-Breasted Women

Administering this treatment facedown results in fewer side effects for some cancer patients.
Stephanie Anderson Witmer
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Stephanie Anderson Witmer

Patients who undergo radiation treatment for breast cancer typically lie on their backs. But a 2022 Canadian study published in JAMA Oncology demonstrates women with larger breasts who receive radiation therapy facedown in the prone position may have fewer post-treatment side effects.

The study included 357 postsurgery breast cancer patients with large breasts (defined as a bra size of at least a D-cup or a 40-inch band). They were randomized to receive the same dosage of radiation either in the prone (lying flat, facedown) or the supine (lying flat, faceup) position. Researchers found women whose body position during radiation treatment was lying on their bellies were up to 50 percent less likely to develop one of the most common and painful side effects of radiation: the skin condition moist desquamation.

Moist desquamation is a breakdown of the skin tissue at the radiation site. It may look like a sunburn and can last for several weeks after treatment. It can be severe enough that the top layer of skin peels away and oozes. Commonplace activities such as bathing or wearing a bra can become uncomfortable or excruciating for patients.

What the study found

The study focused not on better outcomes from the radiation treatment but on improved quality of life for breast cancer patients, according to the study's lead author, Danny Vesprini, M.D., an assistant professor at the University of Toronto and a radiation oncologist at Odette Cancer Centre at Sunnybrook Hospital.

"What we showed was that if you compared women that were on their belly, which was the experimental arm, to those that were on their back, which is the standard way to treat people, the women on their belly were less likely to develop the skin breakdown and less likely to have pain," he said.

Women with larger breasts tend to experience more skin irritation following treatment, explained Eugene Shieh, M.D., a radiation oncologist with GenesisCare in Florida.

"It is a not uncommon event for women undergoing breast radiation, especially larger-breasted women," said Shieh, who was not affiliated with the study. "Typically, it happens in areas where there are skinfolds, such as below the breast or close to the armpit. Those folds are more prevalent in larger-breasted women."

When women with larger breasts lie facedown, their breasts pull away from the chest wall, resulting in fewer skinfolds and side effects to the skin. It's possible women with smaller breasts could benefit as well, but this trial was designed for women with D-cups or larger because they're more at risk for developing those skin reactions.

"A woman with a C-cup very well may benefit the same way, but their risk of getting the side effect in regards to the skin breakdown is a lower percentage to start off with," Vesprini said.

Why supine is the standard

If receiving radiation in the prone position results in fewer skin reactions in certain women, why are they typically treated on their backs? Mostly because it's easier, for both the patient and the radiation technician. Patients usually receive radiation five consecutive days a week for several weeks and they lie in the exact same position each time for about 15 to 20 minutes.

"Radiation is a treatment where you want to be very precise and you want something that's very reproducible," Vesprini said. "Lying on your back is a very natural thing for people to do. It's easy to see the breast. We tattoo people [where they receive radiation], so [it's] easy to access the tattoos. We can make sure everything's in the right position, and patients may feel more comfortable on the back. Lying on your belly is not as stable a position."

Factors such as the patient's body size or the location of the tumor may prevent the prone position from being a feasible option for some people, he added. Additionally, doing the procedure in this position would require radiation centers to purchase a different type of radiation board, one with holes for patients' breasts.

What comes next

"Moving forward, for patients and their doctors, this study likely confirms that in patients with large breasts, shorter treatment schedules for post-op whole-breast radiation lead to less short-term toxicity to the breast than longer schedules," said Neil D'Souza, M.D., a radiation oncologist with Arizona Oncology who was not affiliated with the study. "If a longer schedule is used, then prone positioning for these patients leads to less toxicity."

The study's findings may also have long-term implications. Women who experience more skin reactions during radiation treatment have a higher chance of developing future problems, including cosmetic changes to the skin and chronic pain, Vesprini said. Future research will look at whether limiting these reactions from the start leads to long-term improvements. In addition, Vesprini and his team plan to investigate whether this treatment could also spare the lungs and heart from radiation's side effects.

Vesprini said the novelty of this study was its simplicity: no complicated gadgets, innovative drugs or cutting-edge technology; just flipping patients from their backs to their bellies.

"It's a simple, low-tech solution, but it had a significant improvement," he said. "I think we have to sometimes step back and not always think about the crazy-hard stuff or the very expensive stuff. There's sometimes very easy things we can do to make people's lives better."