comscoreLying Facedown for Radiation Therapy Causes Fewer Skin Side Effects in Women With Large Breasts

Lying Facedown for Radiation Therapy Causes Fewer Skin Side Effects in Women With Large Breasts

During external whole-breast radiation therapy for breast cancer, women with large breasts who lay facedown had fewer skin side effects than women who lay faceup.
Jun 3, 2022.

During external whole-breast radiation therapy for breast cancer, women with large breasts who lay facedown had fewer skin side effects than women who lay faceup, according to a Canadian study.

The research was published online on May 26, 2022, by the journal JAMA Oncology. Read the abstract of “Effect of Supine vs Prone Breast Radiotherapy on Acute Toxic Effects of the Skin Among Women With Large Breast Size: A Randomized Clinical Trial.”

Doctors call lying facedown prone and lying faceup supine.


Whole-breast radiation

For many years, people received external whole-breast radiation on an outpatient basis, usually five days a week for five to seven weeks.

Radiation oncologists measure the dose of radiation therapy in units called the Gray. If you were on a five-week treatment schedule, you’d receive a total of 45 to 50 Gray in five weeks (1.8 to 2 Gray at each of 25 treatments).

But a five- to seven-week nearly daily commitment is difficult for many people, especially if they live far away from a treatment center.

So doctors developed a radiation therapy schedule that involves fewer treatments with higher doses of radiation at each treatment. This accelerated, or hypofractionated, radiation schedule puts about the same radiation dose into a three- to five-week schedule.

People commonly lie faceup when receiving external radiation.


Skin side effects of radiation therapy

External radiation therapy commonly causes skin changes in the treated area. The reaction is much like a sunburn, with redness and possible itching, burning, soreness, peeling, blistering, or darkening of the skin. These changes usually happen gradually throughout your treatment and typically only in certain areas.

You’re more likely to have significant skin side effects if you had mastectomy or chemotherapy before radiation or if you have:

  • fair skin

  • larger breasts

  • certain health conditions that affect skin healing, such as a connective tissue disorder


About the study

A small study found that lying facedown during radiation therapy decreased skin side effects in women with large breasts. In this larger study, the researchers wanted to see if they could duplicate those results.

The study included 357 Canadian women with a bra band size of 40 or larger or a D cup size or larger who had been diagnosed with early-stage invasive breast cancer or DCIS between April 2013 and March 2018. All the women had lumpectomy and were scheduled to have external whole-breast radiation therapy after surgery. No women were scheduled to have radiation to the lymph nodes, and no women had connective tissue disease.

The researchers randomly assigned the women to receive radiation either lying faceup or facedown:

  • 182 women received radiation therapy lying faceup

  • 175 women received radiation therapy lying facedown

The only difference between the two groups was the position in which they received radiation. All the women received the same dose per treatment and the same number of treatments.

When the study began, the women were on a conventional schedule, receiving 2 Gray per treatment for 25 treatments. In 2016, the researchers switched to an accelerated schedule, so the women received 2.6 Gray per treatment for 16 treatments.

Equal numbers of women in each treatment group received a boost dose of radiation — an additional dose to the area where the cancer used to be.

Skin peeling and blistering — called moist desquamation by the researchers — in the breast area as a result of radiation was more common in women who received treatment lying faceup:

  • 39.6% of women who received radiation lying faceup had skin peeling and blistering

  • 26.9% of women who received radiation lying facedown had skin peeling and blistering

This difference was statistically significant, which means it was likely due to the difference in position and not just because of chance.

Women who received radiation lying faceup also had more severe skin peeling and blistering than women who received radiation lying facedown.

There were no differences in breast swelling, redness, or pain between the two groups.

When the researchers looked at the two different treatment schedules, they found that women on the traditional schedule who received radiation lying faceup had more skin peeling and blistering and more pain than women who received radiation lying facedown. These differences also were statistically significant.

For women on the accelerated schedule, overall rates of skin peeling and blistering and pain were lower than women on the traditional schedule. Also for women on the accelerated schedule, the rates of skin peeling and blistering and pain were about the same, no matter which position the women were in when they received radiation therapy.

“Radiation therapy is an important and effective form of treatment for many people with breast cancer,” said Marisa Weiss, MD, director of breast radiation oncology at Lankenau Medical Center, and chief medical officer and founder of “The goal is always to maximize the benefits and reduce any associated side effects. Your position while receiving radiation therapy can affect side effects.

“Lying prone — facedown — on the radiation treatment table can help treat the breast, while reducing the amount of normal tissue and avoiding skin folds in the treatment area,” Dr. Weiss continued. “This is especially true for women with large breasts, who are more likely to develop moist desquamation inside skin folds around the breast. Generally, there are three skin folds: in the armpit, under the breast, and in the cleavage area. Avoiding radiation dose to the heart is also important; the heart is located in the middle on the left side of the chest.”


What this means for you

If you have large breasts and radiation after lumpectomy is part of your treatment plan, you may want to ask your doctor whether receiving radiation lying facedown makes sense for your unique situation.

It’s important to know that advances in radiation therapy have greatly reduced the amount of radiation that the heart, lungs, and other healthy tissues are exposed to, which reduces the risk of skin side effects. Doctors use computers to plan radiation therapy that is extremely precise in dose and delivery.

It’s also important to know that some people — such as people with mobility issues and people who need radiation to the lymph nodes — are likely to receive radiation lying faceup.

“If you receive radiation while lying on your back, there are steps that can be taken to reduce the risk of skin breakdown,” Dr. Weiss explained. “Ask your radiation doctor to use special wedges to keep the skin folds open. Also ask your doctor about using deep inspiration breath hold techniques to reduce the radiation dose to the heart.”

Learn more about Radiation Therapy.

Written by: Jamie DePolo, senior editor

— Last updated on June 28, 2022, 7:51 PM

Reviewed by 1 medical adviser
Brian Wojciechowski, MD
Crozer Health System, Philadelphia area, PA
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