Trial Information

Partial Breast Treatment Using Single Dose Intraoperative Radiotherapy for Patients With Early Stage Breast Cancer - A Feasibility Study With Molecular Analysis of Tumors and Normal Breast Epithelial Tissue

OBJECTIVES:

Primary

- Determine the feasibility of intraoperative partial breast radiotherapy prior to
surgical resection in older women with low-risk early stage primary invasive ductal
carcinoma of the breast.

- Determine the rate of good/excellent cosmesis, as measured by the RTOG cosmetic rating
scale, in patients treated with this regimen.

- Compare the cosmetic outcome in patients treated with this regimen with that of
patients treated with partial breast brachytherapy in clinical trial RTOG-9517.

- Determine the incidence of grade 3-4 toxicity of this regimen in these patients.

- Determine the rate of ipsilateral breast recurrence, including recurrence within the
tumor bed as compared to elsewhere in the breast, in patients treated with this
regimen.

Secondary

- Determine the radiation-induced activation of receptors and signal transduction
pathways involved in radiation response in patients treated with this regimen.

OUTLINE: This is a non-randomized study.

Patients undergo intraoperative lymphatic mapping and sentinel lymphadenectomy OR standard
level I, II axillary dissection to evaluate the lymph nodes followed by intraoperative
breast ultrasonography to define the tumor target volume. Patients then undergo
intraoperative single-dose partial breast radiotherapy followed by segmental mastectomy
(i.e., lumpectomy) of the tumor. Patients with 1 or 2 tumor-involved surgical margins may
undergo repeat segmental mastectomy. Patients with > 2 tumor-involved surgical margins
undergo mastectomy. Patients determined to have a tumor size > 3 cm or an extensive
intraductal component on final pathology evaluation undergo standard external beam
radiotherapy after surgery.

After completion of study treatment, patients are followed every 3 months for 2 years, every
6 months for 3 years, and then annually thereafter.

PROJECTED ACCRUAL: A total of 71 patients will be accrued for this study within 2 to 3
years.