Optimizing Preventative Adjuvant Linac-Based Radiation: the OPAL Trial - Study of Hypofractionated Partial Breast Irradiation in Women With Early Stage Breast Cancer

If you agree to take part in this study, one (1) time before you begin radiation treatment:

- You will complete 1 questionnaire about how your breast currently looks and feels. It
should take about 10 minutes to complete the questionnaires.

- The study team will take pictures of your breast to compare the way it looks before and
after you begin receiving radiation. Your face will be covered (as much as possible) and
will not be included in the pictures.

Length of Study:

You will receive radiation for 2 to 2½ weeks. You will no longer be able to receive radiation
if intolerable side effects occur, or if you are unable to follow study directions. Your
participation will be over after the 5-year follow-up visit.

Study Treatment Administration:

If you agree to take part in this study, you will receive about 2 weeks of radiation (10
treatments) to the part of the breast where the disease first started. If the doctor thinks
it is needed, you will have 3 additional radiation treatments as a "boost." The boost will be
delivered to and focus more closely on the part of the breast where the disease first
started.

Follow-Up Visits:

3 weeks after you have finished receiving radiation, you will have a physical exam.

You will return for additional follow-up visits 6 months and 1, 2, 3, 4, and 5 years after
you have finished receiving radiation. At each visit:

- You will complete the study questionnaire

- The study team will take pictures of both of your breasts.

- You will have a physical exam.

Inclusion Criteria:

1. Age 50 or older.

2. Female sex.

3. Diagnosis of pathologically-confirmed invasive breast cancer or ductal carcinoma in
situ.

4. Pathologic T stage of Tis, T1, or T2 with total size of tumor < /= 3 cm (this size
criteria applies to both pure DCIS and invasive tumors).

5. For patients with invasive breast cancer, pathologic N stage of N0, N0 (i-), or N0
(i+). Pathologic staging of the axilla is not required for patients with pure DCIS.

6. Treatment with breast conserving surgery.

7. Unifocal primary tumor based on imaging and clinical assessment. Microscopic
multifocality is allowed.

8. Final surgical margins negative defined as no tumor on ink. Lobular carcinoma in situ
involving the final surgical margin will be disregarded.

9. For invasive cancers, the tumor must be estrogen receptor positive (defined as 10% or
greater expression of estrogen receptor)

10. If the patient has a history of a prior non-breast cancer, all treatment for this
cancer must have been completed at least one month prior to study registration and the
patient must have no evidence of disease for this prior non-breast cancer.

11. Patients must be enrolled on the trial within 12 weeks of the later of two dates: the
final breast conserving surgical procedure or administration of the last cycle of
cytotoxic chemotherapy.

12. Final criteria for eligibility established after simulation: The tumor bed can be
readily visualized on simulation CT and is localized to one quadrant or region of the
breast that is amenable to partial breast irradiation.

Exclusion Criteria:

1. Tumor invasion of the skin including dermis, chest wall, or pectoralis musculature.

2. Any evidence of nodal positivity beyond pathologic stage of pN0(i+).

3. Systemic chemotherapy prior to final breast conserving surgery.

4. Patient is pregnant or nursing.

5. History of therapeutic irradiation to the breast, lower neck, mediastinum or other
area in which there could potentially be overlap with the affected breast.

6. History of prior invasive or in situ cancer in either breast.

7. Current diagnosis of bilateral breast cancer.

8. History of lupus or scleroderma.