Radiation schedules for breast cancer treatment

If your doctor has recommended radiation therapy for you, you’ll work with your healthcare team to plan your radiation schedule.

Radiation treatments are usually given in a series of short daily doses designed to kill cancer cells in the breast tissue. While the radiation is working to target malignant cells, it can affect some healthy cells around the tumor location. Many plans are five days a week with no treatments on the weekends, which allows healthy cells to recover.

The type of radiation therapy, the dosage, and the number of days or weeks you’ll be treated during your radiation schedule depends on the characteristics of the cancer, including:

• The location and size of the tumor
• The type of cancer-removing surgery you had (lumpectomy or mastectomy)
• Whether cancer cells were found in any lymph nodes

Typical radiation schedules

In early-stage breast cancer, radiation therapy happens after the initial surgery to remove the cancer. When chemotherapy is part of your plan, radiation therapy is delayed until surgery and chemotherapy are complete. If the cancer is metastatic, radiation therapy may be used at any time to treat small areas of cancer that have metastasized to other parts of the body.

A typical schedule for standard whole breast radiation treatment is once a day, five days a week, for three to five weeks. The last week of treatment often includes a boost, or focused treatment, to the area where the tumor was found. According to radiation oncologist Neil K. Taunk, MD, MSCTS, “A three to four week course of whole breast radiation using a slightly higher dose per day but in fewer overall treatments, called hypofractionated radiation, is the most appropriate treatment for women who need treatment to the breast only, with few exceptions.”

It’s important to keep your scheduled appointments. Radiation therapy is most effective when you complete a full course without interruption. Call your radiation treatment center right away if you need to cancel an appointment because of an emergency or illness.

Your radiation oncologist will monitor how well the treatment is working, and you’ll likely have weekly check-ins to talk about any side effects and concerns you may have. Depending on how your body is responding to the treatment, your doctor may adjust the dose or schedule.

Unique radiation schedules

Radiation treatment schedules can vary, and researchers are studying ways to make schedules more convenient. In this section, we’ll look at different kinds of schedules and why doctors may recommend them.

Whole breast radiation therapy treatment schedules

A typical radiation therapy plan is whole breast-only radiation once a day for about 15 minutes a treatment, five days a week, for three to five weeks. Uncommonly, schedules can be as long as seven weeks. This presents challenges if you live far from your treatment facility, have financial difficulties, or can’t take time off work or away from family. The good news is that your healthcare team can often work with you to create a schedule that’s easier.

One way doctors create a shorter whole breast radiation treatment schedule is by slightly increasing the amount of radiation per treatment. This is called hypofractionated dosing. Radiation oncologists measure radiation dosing using a unit called a Gray, or Gy. A typical radiation therapy dose is 25-28 fractions (treatments) of 1.8-2 Gray per treatment. Hypofractionated radiation is given at more than 2 Gy per fraction. This increased dosing allows a person to complete radiation therapy in fewer days or weeks than with lower doses.

For example, if you’ve had a lumpectomy and no cancer was found in any lymph nodes, your doctor could offer you a schedule that allows you to receive a hypofractionated dose over a shorter period. Research shows that in women without cancer in the lymph nodes who’ve had a lumpectomy, the higher dose of radiation in a shorter timeframe is just as effective at reducing the risk of recurrence as longer, lower-dose radiation schedules.

Another way doctors can adapt a whole breast radiation treatment schedule is by significantly increasing the Gray (Gy), or dose, of radiation to give treatment in five once-a-week fractions (treatments) or five fractions in a single week. Right now, the National Comprehensive Cancer Network (NCCN) only recommends this schedule (called ultra-hypofractionated whole breast radiation) for certain adults over the age of 50 who:

• Have early-stage breast cancer
• Had lumpectomy
• Had no lymph nodes test positive for cancer cells

Ultra-hypofractionated whole breast radiation consists of 28.5 Gy of radiation given in five once-a-week fractions, or 26 Gy of radiation given in five consecutive days. Rarely, a boost is given after this schedule. It’s a good option for people who need to travel far to get treatment, or who may have difficulty changing their schedule to be at daily radiation appointments.

Partial breast radiation treatment schedules

In some cases, higher doses of radiation can be given in a shorter time to just one part of the breast. This is called partial breast radiation. Partial breast radiation was developed to reduce the impact that whole breast radiation can have on healthy tissue and organs, including the ribs, heart, and lungs.

Partial breast radiation can be given:

• By external beam radiation using higher doses in a shorter timeframe
• By temporarily placing small amounts of radioactive material inside your breast where the tumor was in a procedure called brachytherapy; brachytherapy is not as available as external beam radiation

In 2023, the American Society for Therapeutic Radiology and Oncology (ASTRO) published new guidelines for partial breast radiation in early-stage invasive breast cancer or ductal carcinoma in situ (DCIS).

For early-stage, invasive breast cancer, ASTRO strongly recommends partial breast radiation instead of whole breast radiation if all of these are true:

• The tumor is estrogen receptor-positive and grade 1 or 2.
• The tumor is two centimeters or less.
• You are age 40 or older.

For DCIS, the ASTRO guidelines strongly recommend partial breast radiation as an alternative to whole breast radiation if all of the following are true:

• The DCIS is grade 1 or 2.
• The DCIS is two centimeters or less.
• You are age 40 or older.

For more details on eligibility for partial radiation, visit the Radiation therapy for breast cancer page.

External beam partial breast radiation is typically given in 30 Gy in five fractions. The five fractions are given every other day, so treatment takes place over two weeks. Other possible schedules:

• 40 Gy given in 15 fractions given once per day
• 5 Gy given in 10 fractions scheduled twice a day for five days. This regimen is less preferred.

If you’re offered brachytherapy, a common schedule is 34 Gy in 10 fractions scheduled twice a day for five days.

Another partial breast radiation procedure called intraoperative radiation therapy (IORT) uses one single, large dose of radiation just after surgeons remove the tumor during lumpectomy. IORT is recommended for use in clinical trials and is not available today at most hospitals.

Your doctors might recommend a partial breast radiation schedule if the traits of the tumor suggest you could benefit from it. You can also ask your doctor if you are an appropriate candidate for partial breast radiation.

Other treatment schedule considerations

Researchers are studying newer approaches that give radiation over other shorter periods, such as single-dose external beam and brachytherapy schedules. They are working to learn more about which people are most likely to benefit from shorter-course radiation.

If you have been diagnosed with metastatic breast cancer and your doctor has recommended radiation therapy to relieve symptoms such as bone pain, your radiation schedule will probably be different than a typical three- to five-week whole breast schedule. You and your doctor will decide on a plan that’s unique to the size and location of the cancer, the reason for treatment, other treatments you are receiving, and your overall health.

As you make a radiation therapy plan, it’s important to know that in many cases, radiation therapy cannot be given more than once to the same part of the body. The body’s organs and tissues can handle a certain, limited amount of radiation, but too much radiation can cause permanent damage. But there are exceptions. Dr. Taunk explains, “In specific situations, repeat radiation to the same area may be recommended. However, the risks of repeat radiation should be discussed with your radiation oncologist. Careful planning by an experienced radiation oncologist is recommended in these situations.”

What to expect at radiation therapy appointments

During your radiation therapy treatment appointments, your healthcare team will help you prepare by explaining:

• The members of your radiation treatment team, who typically include:
  • Your radiation oncologist
  • A radiation therapist trained to use the radiation equipment
  • A radiation therapy nurse or nurses who can provide guidance about the treatment and managing side effects
  • An oncology social worker who can provide emotional support and point you to resources for financial support and transportation assistance
• The risks and benefits of radiation therapy
• The length of each treatment—usually about 15 minutes
• The initial planning or simulation session for treatment, in which your team will:
  • Position you on the treatment table to find the exact area on your body where radiation will be directed.
  • Mark the area with very small tattoos.
  • Teach you how to use devices that keep you from moving when you’re getting treatment. These immobilization devices, such as a breast board or arm immobilizer, help support your body and reduce the risk of radiation to other organs.

If your doctor recommends the deep inspiration breath hold (DIBH) technique to reduce the risk of radiation exposure to your heart, you will be coached on how to hold your breath before treatment begins.

How dosage is monitored

Throughout radiation treatment, your radiation therapy team will pay close attention to your treatment plan and the amount of radiation that’s been recommended for you. During each session, your team will measure and monitor your dose. Technology such as digital imaging systems can see the radiation beam and monitor whether the dose given is the same for each treatment. These techniques allow your team to make sure that the radiation beam is targeting the planned area correctly.

Tips & things to remember

Here are some important things to know as you prepare for radiation therapy:

• If your team puts temporary markings on the radiation treatment area (usually with a felt-tip marker or pen), you may be asked to avoid washing them. If you get tattoo markings, you can bathe normally.
• Talk to your doctor about any over-the-counter drugs, vitamins, and herbal supplements you take. You may be advised to stop taking a drug or supplement temporarily if it interacts with your treatment.
• Your doctor will talk with you about avoiding pregnancy and using reliable birth control during treatment, because radiation can harm a developing baby.
• Radiation therapy can make the treatment area more sensitive to the sun’s rays. Ask your treatment team for recommendations on types of sunscreen and protective clothing.
• After breast cancer surgery, your doctor likely gave you physical therapy exercise guidance for regaining flexibility in your arm. It’s important to keep doing these exercises, because radiation for breast cancer can cause arm and shoulder stiffness. Talk with your doctor about how to exercise your arm safely during and after your radiation treatment.
• If you are receiving external beam radiation treatment, you are not radioactive, and there is no radiation risk to people around you.
• If you receive internal radiation (brachytherapy), your body does give off radiation. If the radiation is a high dose, your doctor may recommend that you stay in a private hospital room while you’re receiving treatment and have limited contact with friends and family. Your doctor will talk with you about safety measures for brachytherapy.
• If you are having difficulty paying for treatment, with transportation to treatments, or any other issues, ask to talk with the hospital social worker. The social worker can often find resources to help you. You can also visit the financial matters section for information on managing costs and insurance.

To learn more about radiation therapy treatment, visit the radiation therapy for breast cancer page.