Partial Breast Radiation Therapy in Treating Women Undergoing Breast Conservation Therapy for Early-Stage Breast Cancer
Partial Breast Radiation Therapy in Treating Women Undergoing Breast Conservation Therapy for Early-Stage Breast Cancer
RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells.

 PURPOSE: This clinical trial is studying the side effects of partial breast radiation therapy
 and how well it works in treating women undergoing breast conservation therapy for
 early-stage breast cancer.
OBJECTIVES:

 -  To allow women undergoing breast conservation therapy for early-stage breast cancer to
 have access to accelerated partial breast irradiation therapy on a controlled trial.

 -  To capture prospective data on acute and late toxicity and disease recurrence in
 patients treated with this therapy.

 -  To summarize the institutional experience of these patients treated with this
 experimental therapy.

 OUTLINE: Within 9 weeks after surgery, patients undergo accelerated partial breast
 irradiation (including conformal external-beam irradiation, interstitial brachytherapy,
 intracavitary brachytherapy, or proton beam irradiation) twice daily for 5 days (10
 fractions).

 After completion of study therapy, patients are followed every 3 to 6 months for at least 5
 years and then annually thereafter.
DISEASE CHARACTERISTICS:

 -  Women who have chosen to undergo breast conservation therapy, including lumpectomy and
 breast irradiation, at the University of Pennsylvania for any invasive mammary
 carcinoma or intraductal breast cancer

 -  Stage I-II invasive or intraductal breast cancer

 -  Unifocal tumor ≤ 3.0 cm in size

 -  Patients with microscopic multifocality are eligible provided total
 pathologic tumor size is ≤ 3 cm

 -  No proven multicentric carcinoma in more than 1 quadrant or separated by 4 or
 more centimeters

 -  Pre- or post-biopsy ipsilateral* breast MRI negative for multicentric
 disease (i.e., areas of cancer that cannot be removed in a single excision
 specimen) or other suspicious findings NOTE: *Patients with synchronous
 bilateral breast cancers who will be treated with radiotherapy to each
 breast are eligible, provided such treatment can be performed in a manner
 that avoids overlap between treatment fields. Both sides may be treated with
 partial breast irradiation (PBI) if the pathologic eligibility criteria are
 met for both tumors, or only one side may be treated with PBI if the
 criteria are met for only one tumor.

 -  Negative margins of excision (≥ 2 mm) OR no tumor seen in a re-excision specimen

 -  No extensive intraductal component present

 -  Negative sentinel lymph node (SLN) or axillary lymph node dissection OR fewer
 than 4 positive nodes on adequate axillary lymph node dissection (i.e., 10 or
 more lymph nodes removed)

 -  If a SLN is positive on hematoxylin and eosin (but not by
 immunohistochemistry alone), complete axillary lymph node dissection is
 required

 -  Axillary lymph node staging is not required for patients with ductal
 carcinoma in situ

 -  No SLN identified in the internal mammary nodes

 -  No node > 2 cm

 -  No node with extracapsular extension

 -  Surgical clips placed in the operative bed OR ability to visualize operative bed on CT
 scan of the breast

 -  Target lumpectomy cavity/whole breast reference volume must be ≤ 30% based on the
 treatment planning CT scan

 -  No diffuse calcifications on diagnostic mammogram

 -  Negative post-biopsy mammogram required if presented with mammographically
 detected microcalcifications

 -  Hormone receptor status unspecified

 PATIENT CHARACTERISTICS:

 -  Female

 -  Menopausal status not specified

 -  History of non-breast malignancies allowed provided patients have been disease free
 for 5 or more years prior to randomization and are deemed by their physician to be at
 low risk for recurrence

 -  Treated carcinoma in situ of the cervix, carcinoma in situ of the colon, melanoma
 in situ, or basal cell and squamous cell skin cancer within the past 5 years
 allowed

 -  Patients must agree to undergo breast MRI

 -  No contraindication to MRI, including a pacemaker or other foreign body

 -  Not pregnant or nursing

 -  No technical impediment to appropriate dosimetry

 -  No personal history of collagen vascular disease

 PRIOR CONCURRENT THERAPY:

 -  See Disease Characteristics

 -  No prior in-field irradiation

 -  No presence of breast implant

 -  No breast reconstructive surgery prior to study entry

 -  No prior neoadjuvant chemotherapy or hormonal therapy