Complete blood count (CBC)/differential obtained within days prior to step registration Blood cell count (CBC)/differential obtained within days prior to registration on study Prestudy history and physical must be obtained within days prior to registration; patients must have a complete blood count (CBC) and basic metabolic panel including creatinine, potassium, chloride, blood urea nitrogen (BUN), carbon dioxide (CO) and glucose within days prior to registration The following laboratory values obtained =< days prior to registration; complete blood count (CBC), sodium, potassium, aspartate aminotransferase (AST), bilirubin and creatinine are to be obtained pre-study; Note: treatment initiation and dosing modification should be performed at the individual investigators discretion and be consistent with the product label and their medical practice Blood cell count (CBC)/differential obtained within weeks prior to registration on study Absolute neutrophil count >= , cells/mm^ based on complete blood count (CBC)/differential within days prior to Step registration Platelet count >= , cells/mm^ based on CBC/differential within days prior to Step registration Hemoglobin > . g/dl (may be transfused to achieve this level) based on CBC/differential within days prior to Step registration Patients must not have metastatic disease on staging work-up with blood cell count (CBC) and liver function studies No evidence of recurrent local or distant breast cancer by physical examination, blood tests (complete blood count [CBC], liver function tests [LFTs], alkaline phosphatase [alk phos]), or symptom-directed imaging, per National Comprehensive Cancer Network (NCCN) guidelines DONOR: Complete blood count (CBC) with differential and platelet count within normal limits, as deemed acceptable by the principal investigator Complete blood count (CBC)/differential obtained within days prior to starting the study drug with adequate bone marrow function, defined as follows: Microcytosis on screening blood cell count (CBC) (mean corpuscular volume [MCV] < fL) Complete blood count (CBC) - no clinically significant findings Complete blood count (CBC) with differential and a comprehensive metabolic panel (CMP) including liver function tests (LFTs) obtained within days prior to registration A complete blood count and differential must be obtained within days prior to radiation fraction DONOR: Complete blood count (CBC) within one week of donation; results of tests must be within a range that would not preclude donating blood or undergoing leukapheresis Complete blood count/differential at screening with adequate bone marrow function Complete blood count (CBC)/differential obtained no more than weeks prior to registration on study, with adequate bone marrow function Complete blood count, differential and platelet count must be within normal limits (WNL) or verified by the study chair to be related to conditions not interfering with normal health status Complete blood count (CBC)/differential obtained within days of registration on study (or within days prior to day of chemotherapy post-surgery for those patients having started chemotherapy prior to first step registration) Complete blood count (CBC)/differential obtained within days prior to registration on study, with adequate bone marrow function Complete blood count (CBC) without clinically significant abnormalities after review by the study physicians For patients undergoing brachytherapy only: complete blood count (CBC)/differential obtained within days prior to registration, with adequate bone marrow function defined as follows: Absolute neutrophil count (ANC) >= cells/mm^ based on complete blood count (CBC)/differential obtained within days prior to study registration Platelets >= , cells/mm^ based on CBC/differential obtained within days prior to study registration Complete blood count (CBC)/differential obtained within days prior to registration, with adequate bone marrow function DONOR: Complete blood count (CBC)/diff/platelet count near normal limits (+/- %) Hemoglobin > . g/dl based upon complete blood count (CBC)/differential obtained within weeks prior to registration on study DONOR: Complete blood count (CBC)/diff/platelet count near normal limits (plus/minus %) Patients must have adequate organ function, defined as (Note: Complete Blood Count (CBC) test should be obtained without transfusion or receipt of stimulating factors within weeks before obtaining screening blood sample): Complete blood count (CBC), differential and platelet count Acceptable hemoglobin and hematocrit level based on complete blood count (CBC) Subject has no access to a telephone. . Subject has no documented blood values (complete blood count [CBC], coagulation tests, urea and electrolytes, and liver function tests [LFTs]) within the last days. Patient or legal representative must agree to blood serum assessment including, complete blood count (CBC) with differential, comprehensive metabolic panel and serum osmolality at every sanctioned evaluation; additionally physician may require cardiac evaluation with echocardiogram, electrocardiogram, brain naturetic peptide or urinalysis if deemed appropriate A complete blood count (CBC) and chemistry profile (Cohort A), must have been performed after completion of any breast cancer surgery, radiation therapy, or cytotoxic chemotherapy, with reasonably normal liver and renal function as well as a hemoglobin of or higher and/or performed within a year of study entry A complete blood count (CBC) and chemistry profile, must have been performed after completion of any breast cancer surgery, radiation therapy, or cytotoxic chemotherapy, with reasonably normal liver and renal function and a hemoglobin of or higher Have reasonable organ function as documented by complete blood count (CBC) and metabolic chemistry profile (within months prior to study entry visit) Screening laboratory values (comprehensive metabolic panel, complete blood count [CBC], complete urinalysis, a urinary drug screen, and, if applicable, FSH) within institutional normal range or judged to be not clinically significant by the site principal investigator (PI) and medical monitor Complete blood count (CBC) including diff & platelets - without clinically significant abnormalities CBC (complete blood count) without clinically significant abnormalities after review by the study physicians Although not mandated by the protocol, the results of the computed tomography (CT) scans and labs (complete blood count [CBC], comprehensive metabolic panel [CMP]) that are performed as part of the standard work up should be available and should have been done within months prior to study entry Physical exam, complete blood count (CBC) and multiphasic (including electrolytes, blood urea nitrogen [BUN], creatinine, total bilirubin, aspartate aminotransferase [AST], and alanine aminotransferase [ALT]) must be done within days of PET imaging, but eligibility is not restricted by these results; the CBC and multiphasic may be drawn at the time of imaging Note: Complete blood count (CBC) and differential should be reported for the phenotyped sample.