Patient Care and Research

SSO/ASTRO/ASCO Consensus Guideline on Margins for Breast Conserving Surgery (BCS) with Whole Breast Irradiation in Ductal Carcinoma in Situ (DCIS) 

Published: September 2016 (Web posted June 2016)

Read Full-Text Guideline

This collaborative guideline focuses on several elements of optimal margin negative margin width for DCIS treated with breast-conserving surgery and whole breast irradiation. It defines positive margins and provides recommendations on negative margin width. It also discusses the impact on negative margin width of treatment with excision alone or with endocrine therapy; patient and tumor features; and DCIS in presence of invasive breast cancer. The role of margin width in choice of technique, fractionation and boost dose for whole breast irradiation is also covered.

Developed in collaboration with:

  • American Society for Radiation Oncology
  • American Society of Clinical Oncology
  • Society of Surgical Oncology

Endorsed by:

American Society of Breast Surgeons

Key Points:

  • Determination of optimal margin width to minimize risk of ipsilateral breast tumor recurrence
  • Whole-breast radiation therapy (WBRT) in combination with excision
  • Excision alone
  • Endocrine therapy
  • Consideration of unfavorable risk factors in determining margin width
  • Choice of WBRT delivery technique, fractionation and boost dose
  • Considerations for DCIS with microinvasion when determining optimal margin width


Radiation Therapy for Breast Cancer (CME)
Summary Recommendation Table (SSO)
Guideline Summary PowerPoint Presentation (Slides) 
Patient Brochure

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