Partial-Breast Radiation Therapy in Treating Women With Early-Stage Breast Cancer

DISEASE CHARACTERISTICS:

• Histologically confirmed ductal carcinoma in situ (DCIS) of the breast or invasive breast adenocarcinoma

  • Stage 0, I, or II (T2, N0; tumor size ≤ 3 cm) disease

  • Pathologic staging of the axilla preferred

    • Clinical staging of the axilla allowed for patients ≥ 70 years of age with hormone receptor-positive tumors

• Unicentric tumor

  • Microscopic multifocality allowed as long as the total tumor size is ≤ 3 cm

• Must have undergone lumpectomy as definitive surgery

  • Negative surgical margins, defined as no tumor at the inked margin of resection after final surgery

    • Re-excision to obtain negative margins allowed
• Must have adequate skin spacing between balloon surface and surface of the skin and lung (≥ 7 mm)
• No multicentric carcinoma (invasive or DCIS) in more than one quadrant
• No clinically or pathologically positive regional lymph nodes
• No extensive intraductal component, defined as DCIS extending beyond the primary invasive component into normal breast parenchyma and composing > 25% of the primary tumor
• Hormone receptor status not specified

PATIENT CHARACTERISTICS:

• Menopausal status not specified
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

• No collagen-vascular disease, including any of the following:

  • Dermatomyositis
  • Systemic lupus erythematosus
  • Scleroderma-mixed connective tissue disease

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics