A Trial of 15 Fraction vs 25 Fraction Pencil Beam Scanning Proton Radiotherapy After Mastectomy in Patients Requiring Regional Nodal Irradiation


  • Study type

  • Study phase

  • Study IDs

  • Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.
  • During the early phases (phases 1 and 2), researchers assess safety, side effects, optimal dosages and risks/benefits. In the later phase (phase 3), researchers study whether the treatment works better than the current standard therapy. They also compare the safety of the new treatment with that of current treatments. Phase 3 trials include large numbers of people to make sure that the result is valid. There are also less common very early (phase 0) and later (phase 4) phases. Phase 0 trials are small trials that help researchers decide if a new agent should be tested in a phase 1 trial. Phase 4 trials look at long-term safety and effectiveness, after a new treatment has been approved and is on the market.

  • Site IRB
    • Scottsdale/Phoenix, Arizona: 15-006137
    • Rochester, Minnesota: 15-006137
    NCT ID: NCT02783690
    Sponsor Protocol Number: MC1631

About this study

The purpose of this trial is to determine the safety of 15 fraction vs 25 fraction pencil beam scanning proton radiotherapy after mastectomy in patients requiring regional nodal irradiation. Proton therapy is recognized as a standard option for the delivery of radiotherapy for breast cancer.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

See eligibility criteria

Inclusion Criteria

  • Age ≥ 18 years
  • Histologic confirmation of breast cancer
  • Resected by mastectomy with or without immediate reconstruction 
  • Chest wall and regional nodal irradiation planned
  • pStage T1-T4N0-N3M0 or ypStage T0-4N0-N3M0 
    • The axilla must be staged by sentinel node biopsy alone, sentinel node biopsy followed by axillary node dissection, or axillary lymph node dissection alone
  • ECOG Performance Status 0 to 2 (Appendix I)
  • Negative pregnancy test done ≤ 7 days prior to registration, for women of childbearing potential only
  • Radiotherapy must begin within 12 weeks of last surgery (breast or axilla) or last chemotherapy
  • Breast implants and expanders are allowed
  • Able to and provides IRB approved study specific written informed consent
  • Ability to complete questionnaire(s) by themselves or with assistance
  • Able to complete all mandatory tests listed in section 4.0
  • Willing to return to enrolling institution for follow-up during the active monitoring phase of the study
  • Willing to provide tissue and blood samples for correlative research purposes
  • Rochester and Arizona patients must be willing to sign consent onto the Mayo Clinic Radiotherapy Patient Outcomes Registry and Biobanking study, IRB number 15-000136
  • Rochester patients must be willing to sign consent onto Evaluation of cardiac function in patients undergoing proton beam or photon radiotherapy, IRB number 15-007443

Exclusion Criteria

  • Medical contraindication to receipt of radiotherapy
  • Severe active co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens
  • Uncontrolled intercurrent illness including, but not limited to
    • Ongoing or active infection
    • Symptomatic congestive heart failure
    • Unstable angina pectoris
    • Cardiac arrhythmia
    • Psychiatric illness/social situations that would limit compliance with study requirements or providing informed consent
  • Active systemic lupus or scleroderma
  • Pregnancy or women of childbearing potential who are sexually active and not willing/able to use medically acceptable forms of contraception
  • Prior receipt of ipsilateral breast or chest wall radiation that would result in significant overlap of radiation therapy fields
    • Prior contralateral radiotherapy for breast cancer is allowed
  • Positive margins after definitive surgery
  • History of non-breast malignancies except for in situ cancers treated only by local excision and basal cell and squamous cell carcinomas of the skin within 5 years prior to study entry
  • Inflammatory breast cancer
  • Recurrent breast cancer
  • Boosts to the chest wall after mastectomy
    • Nodal boosts are allowed

Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status Contact

Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

Robert Mutter, M.D.

Contact us for the latest status

Contact information:

Cancer Center Clinical Trials Referral Office


Rochester, Minn.

Mayo Clinic principal investigator

Robert Mutter, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office



Mayo Clinic Footer