Radiation therapy after mastectomy and breast reconstruction: what RT CHARM showed

For patients who have had or are planning reconstruction after removal of the breast, the course of radiation therapy can be shortened from 25 to 16 sessions. That is nine trips for radiation that can be avoided.

In October 2026, the RT CHARM results were published in the Journal of Clinical Oncology. The short course met the pre-specified non-inferiority criterion for the risk of reconstruction complications.

This news is particularly relevant for women after the surgical stage of breast cancer treatment who are scheduled for postoperative radiation.

What it is about

• 16 sessions over about three weeks were compared with 25 sessions over five weeks.
• The trial studied treatment after mastectomy with immediate or delayed reconstruction, using an implant or the patient's own tissue.
• The main question of the trial concerned reconstruction complications. The short regimen passed the non-inferiority test.

Key trial numbers

• 898 patients were enrolled. Median follow-up was 3.9 years.
• Radiation regimens: 42.56 Gy in 16 sessions or 50 Gy in 25 sessions.
• Reconstruction complications at two years: 12.3% with the short course and 10.2% with the standard course. Wound-healing problems, repeat hospitalizations, capsular contracture around the implant, unplanned surgeries and reconstruction failure were counted.
• Recurrence in the surgical area or regional lymph nodes at three years: 1.5% vs. 2.2%, respectively. No statistically significant difference was found.
• The rates of early and late side effects did not differ statistically.
• With implant-only reconstruction, complications were more frequent than with the patient's own tissue, regardless of the radiation regimen (odds ratio 1.65).

Why this matters for practice

The shortened course is called moderate hypofractionation: a higher dose is delivered per session, so fewer sessions are needed. The total dose and the whole treatment plan are calculated for this regimen. For the patient, the practical difference can be substantial: fewer trips, lower costs of staying near the center and less time away from family.

At the same time, hypofractionation is already part of current practice. The joint 2025 ASTRO, ASCO and SSO guideline names it as the preferred option after mastectomy, including with reconstruction; conventional fractionation is also acceptable. The new publication therefore strengthens the evidence base for an approach that is already in use.

Practical takeaway: the duration of radiation should be discussed when the overall treatment plan is drawn up. Coordination between the oncologist, the radiation oncologist and the reconstructive surgeon matters here, as do the condition of the tissues after surgery and the ability to protect the heart and lungs. The presence of an implant calls for careful planning but should not automatically rule out a discussion of the short regimen.

Limitations: what does not change yet

The trial had selection limitations. In particular, it did not include patients with distant metastases, T4 tumors, N3 lymph node involvement, prior chest radiation or serious postoperative complications. The protocol also did not include an additional higher-dose boost to the scar. The RT CHARM conclusions cannot be automatically applied to such situations.

The trial does not answer the question of whether radiation therapy after mastectomy can be omitted altogether. The indications for radiation and the choice of its regimen require separate decisions.

You must not stop a prescribed course on your own after the 16th session or skip treatments. If treatment has already started, any changes must be assessed by the radiation oncologist, taking into account the dose actually received.

When a second opinion is especially useful

• Radiation has been recommended after mastectomy, but its purpose, extent or duration is unclear.
• Reconstruction has already been performed or is planned, and the sequence of stages has not been coordinated.
• The radiation oncologist and the surgeon propose different treatment options.
• A long course has been prescribed, and the patient wants to understand whether the shortened regimen applies to her situation.
• There were surgical complications, prior radiation or other circumstances that require a separate review.

What to prepare for the consultation

• Histopathology report and results of the examination of the surgical specimen.
• Mastectomy operative report and information about the reconstruction, implant or tissue expander.
• Discharge summaries for the drug therapy received.
• CT, MRI, PET-CT and other imaging results, preferably together with the images.
• Biomarker data: ER, PR, HER2, Ki-67.
• Molecular testing results, if performed.
• The radiation oncologist's report with the proposed regimen and treatment fields; if treatment has started, information on the dose received.
• Recent blood tests.
• A list of comorbidities and current medications.

There is no need to undergo all of these tests specifically before the consultation. Bring the documents you already have; the doctor will decide whether additional tests are needed.

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