New guidelines say accelerated whole-breast irradiation should be used to treat most breast cancers

Home Blog New guidelines say accelerated whole-breast irradiation should be used to treat most breast cancers

The American Society for Radiation Oncology (ASTRO) has put out updated guidelines on whole-breast radiation therapy.

The updated guidelines say that most women diagnosed with breast cancer should be treated with accelerated whole-breast irradiation as the standard of care. The new guideline greatly increases the number of women recommended to have accelerated whole-breast irradiation.

The updated guidelines were published online on March 12, 2018 by the journal Practical Radiation Oncology. Read “Radiation therapy for the whole breast: Executive summary of an American Society for Radiation Oncology (ASTRO) evidence-based guideline.”

The new guideline replaces the ASTRO guideline released in 2011, which recommended accelerated whole-breast irradiation for selected patients only: mainly women 50 and older when diagnosed and women diagnosed with breast cancer that was small and had not spread to the lymph nodes.

Women diagnosed with early-stage breast cancer who have lumpectomy to remove the cancer usually have radiation therapy after surgery. Radiation therapy after lumpectomy lowers the risk of the cancer coming back (recurrence) and makes lumpectomy as effective as mastectomy.

Whole-breast radiation therapy after breast cancer surgery is usually given as one treatment per day, 5 days a week, for 5 to 7 weeks. A Gray is the way radiation oncologists measure the dose of radiation therapy; if you’re on a 5-week treatment schedule, 50 Gray is the usual amount given during the 5 weeks (2 Gray at each treatment). A supplemental “boost” dose may be included at the end of the regimen that targets the area where the cancer was.

Radiation treatment schedules were developed based on research results. But a 5- to 7-week nearly daily commitment may be difficult for some women, especially if they live far away from a treatment center. So doctors developed and studied a different radiation therapy schedule that involves fewer treatments with higher doses of radiation at each treatment, but the same total radiation dose. This accelerated, or hypofractionated, radiation schedule puts the same radiation dose into a 3- to 5-week schedule.

A hypofractionated whole-breast radiation schedule is appealing to doctors and people getting radiation for several reasons:

  • convenience: arranging daily trips to get treatment can be a problem for some women; fewer treatment days or a shorter period of time may be easier to schedule
  • if radiation is more convenient to schedule, it’s probably easier for women to get all the recommended radiation therapy

"Recent long-term results from several large trials strongly support the safety and efficacy of accelerated treatment for most breast cancer patients," guideline task force co-chair Benjamin Smith, of the University of Texas MD Anderson Cancer Center in Houston, said in a statement. "Conventional therapy does not provide an incremental benefit in either tumor control or side effects compared to hypofractionated whole-breast irradiation."

To write the updated guideline, ASTRO experts reviewed 100 studies on hypofractionated whole-breast irradiation published between 2009 and 2016.

The guideline provides doctors with guidance for dosing, planning, and delivering whole-breast irradiation with or without an additional boost. Key recommendations in the guideline are:

  • Treatment decisions, including decisions between hypofractionated and conventional whole-breast irradiation, should be personalized for each patient.
  • The preferred hypofractionated dose schedule is 4,000 Centigray (cGy) in 15 doses or 4,250 cGy in 16 doses.
  • The decision to offer hypofractionated whole-breast irradiation should not depend on:
    • cancer grade
    • whether the cancer is in the right or left breast
    • previous chemotherapy
    • previous or current treatment with Herceptin (chemical name: trastuzumab) or hormonal therapy
    • breast size
  • For women diagnosed with DCIS, hypofractionated whole-breast irradiation may be used an alternative to conventional dosing.
  • For women diagnosed with invasive breast cancer, a boost to the area where the cancer used to be is recommended for cancers with positive margins, women who are age 50 or younger, and women age 51-70 with high-grade breast cancer.
  • For women who are older than 70 with low-to-intermediate grade disease, and women with hormone-positive disease with wide negative margins, a boost to the area where the cancer was is not recommended.
  • For women diagnosed with DCIS, a boost to the area where the cancer used to be is recommended for women age 50 and younger, women with high-grade cancer, and women with positive or close margins.
  • Three-dimensional conformal (3-D CRT) treatment planning with a forward planned, field-in-field technique is recommended.

"These guidelines apply to most women diagnosed with breast cancer," said Marisa Weiss, M.D., chief medical officer and radiation oncologist. "There are some exceptions, however. The ability to deliver a larger daily dose requires that your doctor design a radiation treatment plan that is very even throughout the whole area of the breast. Sometimes this is hard to achieve. In women with very large breasts or who have a large chest size, it may be hard to achieve an even dose, so your doctor may recommend a traditional dose schedule of 5 to 7 weeks.

"It is important for each person to get the best care possible for her unique situation," she continued. "The hypofractionated schedule is likely more convenient and less disruptive in your busy life. Still, if you have to have a longer treatment plan, don’t think that this means you have a worse situation or worse outcome. These guidelines have no impact on prognosis or how well you do."

If you’ve been diagnosed with early-stage breast cancer that has been removed with lumpectomy and radiation therapy will be part of your treatment plant, it makes sense to talk to your doctor about the new ASTRO guideline and whether hypofractionated whole-breast irradiation makes sense for you and your unique situation.

It’s also a good idea to talk to your doctor about skin reactions to radiation -- together you can develop a plan to ease any skin irritation that happens during and after radiation therapy.



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