Inclusion Criteria:

- Ductal carcinoma in situ (DCIS) or invasive ductal, medullary, papillary, colloid
(mucinous) lobular or tubular histologies.

- American Joint Committee on Cancer (AJCC) DCIS or Stage T1- T2, N0 histologically
confirmed invasive carcinoma of the breast treated with partial mastectomy with
axillary evaluation as appropriate, axillary node dissection or sentinel node biopsy
(SLN). Patients with DCIS with or without SLN or axillary node dissection are
eligible. Patients greater than 70 years old, with stage 1 disease who are
estrogen/progesterone receptor positive (ER/PR+), with or without SLN or axillary
node dissection are also eligible.

- Partial mastectomy with or without reconstruction consisting of local tissue
rearrangement and/or reduction mammoplasty (ipsilateral and bilateral). Patients who
have undergone surgery and/or chemotherapy prior to treatment with radiation therapy
are still eligible for enrollment and all evaluations and photographs will begin
prior to radiation. Retrospective Placement of at least 3 surgical clips in the
lumpectomy cavity is strongly encouraged. Retrospective data may be collected on
women who have completed their entire course of treatment as long as they are
formally consented.

- Unifocal breast cancer which may be encompassed by excision of a single portion of
breast tissue.

- Negative inked histologic margins of partial mastectomy or re-excision specimen to be
confirmed prior to radiation. Positive margins are unacceptable. Every effort
should be made by the surgeon to obtain negative margins with the initial excision.

- Negative post-partial mastectomy mammography (if malignancy associated
micro-calcifications were initially present.)

- Tamoxifen or Arimidex therapy is allowed. If chemotherapy is administered prior to
radiation (but following surgery), then a minimum of two weeks must elapse prior to
the start of radiation therapy.

- The patient must be 50 years of age or older.

- Signed study-specific informed consent form prior to study entry.

Exclusion Criteria:

- Patients enrolled on another clinical trial involving any treatment which may affect
the cosmesis of the bilateral breasts. This would include the taking of medications,
vitamin supplements, variation in radiation or surgery or topical application to the
breast.

- Patients who are node positive.

- Patients with distant metastases.

- Palpable or radiographically suspicious contralateral axillary, supraclavicular,
infraclavicular or internal mammary nodes, unless there is histologic confirmation
that these nodes are negative for tumor.

- Any previously treated contralateral breast carcinoma or synchronous ipsilateral
breast carcinoma.

- Prior non-hormonal therapy or radiation therapy for the current breast cancer; prior
chemotherapy if administered less than two weeks from the start of therapy.

- Patients with Paget's disease of the nipple.

- Patients with prior breast reconstructive surgery including breast mastopexy or
breast augmentation.

- Patients with skin involvement, regardless of tumor size.

- Patients with collagenous diseases, specifically systemic lupus erythematosis,
scleroderma or dermatomyositis.

- Patients with severe peripheral vascular disease or coronary artery disease (ex.
Previous acute myocardial infarction requiring stents or coronary artery bypass graft
within past two years; prior bypass graft of any type etc.)

- Patients with co-existing medical conditions with life expectancy less than 5 years.

- Patients with psychiatric disorders that would preclude obtaining informed consent.

- Other malignancy except non-melanomatous skin cancer less than 5 years prior to
participation in this study; the disease free interval from any prior carcinoma must
be continuous.

- Patients who are pregnant or lactating.