CyberKnife Stereotactic Accelerated Partial Breast Irradiation (SAPBI)
CyberKnife Stereotactic Accelerated Partial Breast Irradiation (SAPBI)
This study will prospectively evaluate the technical feasibility, acute toxicity, late
 effects and oncologic outcomes of CyberKnife Stereotactic Accelerated Partial Breast
 Irradiation (CK-SAPBI) in early stage breast cancer. It will evaluate quality of life (QOL)
 issues as they relate to treatment-related side effects and cosmetic results.
This study will determine the feasibility, acute and late toxicity as well as oncologic
 outcomes following CK-SAPBI.
Inclusion Criteria:

 -  -Newly diagnosed Stage 0 or I breast cancer.

 -  On histological examination, the tumor must be DCIS or invasive non-lobular carcinoma
 of the breast

 -  Surgical treatment of the breast must have been wide excision, lumpectomy or partial
 mastectomy

 -  Age 50 years or greater

 -  ER positive: (≥1% of breast tumor cells express ER in their nuclei)

 -  PR (progesterone receptor) positive: (≥ 1% of breast tumor cells express PR in their
 nuclei)

 -  Her2 negative (IHC 0-1+; for IHC 2+, FISH (fluorescence in situ hybridization) must be
 non-amplified)

 -  Subjects with invasive tumors should undergo axillary sentinel lymph node evaluation
 or axillary lymph node dissection.

 -  Negative inked surgical margins of excision or re-excision, clear of invasive tumor
 (no cells on ink) and DCIS by at least 1 mm

 -  Negative post-excision or post-reexcision mammography if cancer presented with
 malignancy-associated microcalcifications with no remaining suspicious calcifications
 in the breast before radiotherapy. Alternatively, a specimen radiograph can be
 obtained showing all the suspicious calcifications.

 -  No involved axillary lymph nodes, N0(i+) allowed

 -  Enrollment and the plan to initiate of CyberKnife therapy within 12 weeks of the last
 breast cancer surgery.

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

 -  Signed study-specific informed consent form

 Exclusion Criteria:

 -  -Patients with invasive lobular carcinoma or nonepithelial breast malignancies such as
 sarcoma or lymphoma.

 -  Patients with tumors greater than 2 cm

 -  Patients with surgical margins which cannot be microscopically assessed or not cleared
 by at least 2mm at pathological evaluation.

 -  Patients with multicentric carcinoma or with other clinically or radiographically
 suspicious areas in the ipsilateral breast unless confirmed to be negative for
 malignancy by biopsy. Breast MRI will be recommended to exclude multicentric disease
 and additional suspicious areas will require biopsy to exclude malignancy.

 -  Patient with lymphovascular space invasion (LVSI).

 -  Patients with involved axillary nodes.

 -  Patients with collagen vascular diseases.

 -  Patient with known deleterious BRCA1/2 mutations or known mutations in other high
 penetrance genes (TP53, STK11, PTEN-phosphatase and tensin homolog, CDH1)

 -  Patients with prior ipsilateral breast irradiation.

 -  Patients with prior ipsilateral thoracic irradiation.

 -  Patients with Paget's disease of the nipple.

 -  Patients with diffuse suspicious microcalcifications.

 -  Patients with suspicious microcalcifications remaining on the post-excision mammogram.

 -  Patients receiving (neo)adjuvant systemic therapy other than hormonal therapy

 -  Patients with oncoplastic reconstruction and absence of surgical clips