The goal of this study is to find out which immune molecules, cells, and genes are involved in the development of lymphedema (LE), so that medicines that target them can be considered for treating lymphedema. The hypothesis is that LE is a systemic, autoimmune-like disease that is initiated by inflammatory cytokines induced by surgery, radiation, and possibly chemotherapy in genetically susceptible patients.

Inclusion Criteria:

• Participants must be at least 18 years of age
• Participants must have been clinically diagnosed with breast cancer and scheduled for axillary lymph node dissection (ALND) and radiation treatment at MD Anderson (receiving chemotherapy, mastectomy or breast-conserving surgery, ALND (>10 nodes) and radiation treatment for breast cancer, identified by Drs. Mittendorf and Shaitelman of the Nellie B. Connally Breast Cancer Center at MD Anderson)
• Ambulatory and possessing all four limbs
• No prior radiation therapy
• Negative urine pregnancy test within 36 hours prior to study drug administration, if of childbearing potential
• Females participants must complete the Female Enrollment Form. Childbearing potential participants must agree to use one of the medically accepted forms of contraception for a period of one month after study participation. Female participants who meet the criteria for non-childbearing will still complete the Female Enrollment Form, but are not restricted to the use of contraception following study participation.

Exclusion Criteria:

• Participants with a known or suspected allergy to iodine
• Participants who are breastfeeding, pregnant or trying to become pregnant
• Severe underlying chronic illness or disease (other than breast cancer)
• Participants not capable of keeping moderately still for the imaging portion of the study session (~1 hour for imaging)