4D Image-Guided Partial Breast Radiation in Stage 0 and l Breast Cancer

Inclusion Criteria

• •The patient must consent to be in the study and must have a signed an approved consent form conforming with institutional guidelines.
• •Patient must be \> 50 years old.
• •The patient should have a life expectancy of at least two years with a karnofsky performance status \> 70.
• •The patient must have stage 0 or I breast cancer.
• •On histological examination, the tumor must be DCIS or invasive adenocarcinoma of the breast.
• •Surgical treatment of the breast must have been lumpectomy. The margins of the resected specimen must be histologically free of tumor (\>2mm, DCIS and invasive). Re-excision of surgical margins is permitted.
• •Gross disease must be unifocal with pathologic (invasive and/or DCIS) tumor size 2 cm or less. (Patients with microscopic multifocality are eligible as long as total pathologic tumor size is 2 cm or less.)
• •Patients with invasive breast cancer are required to have axillary staging which can include sentinel node biopsy alone (if negative), sentinel node biopsy followed by axillary dissection or sampling with a minimum total of 6 axillary nodes or axillary dissection alone (with a minimum of 6 axillary nodes). Axillary staging is NOT required for patients with DCIS.
• •The patient must have simulation within 8 weeks/56 days of the final surgery for their breast cancer (lumpectomy, re-excision of margins, or axillary staging procedure).
• •Chemotherapy is permitted if planned for ≥ 2 weeks after radiation.
• •Urine pregnancy test must be performed and be negative on all women younger than 60 who have not had a tubal ligation, oophorectomy, or hysterectomy.
• •Separate incisions for the lumpectomy and sentinel node biopsy should be present. Use of only one incision will typically result in a contiguous cavity with the tumor bed and the sentinel node sampling, and inability of the radiation oncologist to delineate the tumor bed from the sentinel node bed.
• •The patient must have a cavity which is able to be targeted with external beam APBI, either through surgical clip placement, or CVS 3 or higher. The cavity to whole breast ratio must be 30% or less.