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

A Single Institution, Prospective, Non-randomized Study of Partial Breast Irradiation Using the MammoSite Radiation Therapy System (Breast Brachytherapy Applicator)

RATIONALE: Internal radiation therapy uses radioactive material placed directly into or near a tumor to kill tumor cells. It may also cause less damage to normal tissue.

PURPOSE: This phase II trial is studying how well partial-breast radiation therapy works in treating women with early-stage breast cancer.

OBJECTIVES:

Primary

• To examine the efficacy of MammoSite® Radiation Therapy System (RTS) in delivering partial-breast irradiation to women with early-stage breast cancer.

Secondary

• To assess the toxicities associated with MammoSite® RTS in these patients.
• To evaluate the cosmetic results in the breast after brachytherapy with the MammoSite® RTS.
• To correlate the cosmetic results with the use of chemotherapy, volume of the implant, and distance from the implant to the skin.
• To correlate the local recurrence rate with time between surgery and implant.

OUTLINE: Patients undergo placement of the MammoSite® Radiation Therapy System (RTS) device into the cavity where the tumor was removed either at the time of surgery or percutaneously under ultrasound guidance after surgery. Within 2-5 days after the device implant, patients undergo partial-breast irradiation delivered by MammoSite® RTS twice daily for 5 days.

After completion of study therapy, patients are followed up periodically for 5 years.

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