Breast cancer is estimated to affect approximately 300,000 women in the US in 2023. Studies demonstrate that 1 in 5 will develop breast cancer related lymphedema secondary to the treatments that they receive. BCRL at this time has no cure, however early detection can prevent the progression to late stage BCRL. At this time a technique of arm massage, manual lymphatic drainage (MLD), is used for treatment. This study investigates a new method of MLD, which is guided by the individual patients' lymphatic anatomy through use of ICG-lymphography.

Inclusion Criteria:

• Adults ≥ 18 years of age
• Patients undergoing axillary lymph node dissection with or without lymphatic reconstruction at diagnosis
• Patients must have ICG lymphatic mapping performed prior to axillary lymph node dissection
• A clinical diagnosis consistent with stage Tis-T4N0-3M0 breast cancer.
• ECOG Performance Status of 0-1
• Subjects must not have more than one active malignancy at the time of enrollment (Subjects with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen [as determined by the treating physician and approved by the PI] may be included).
• Written informed consent obtained from the subject and the subject agrees to comply with all the study-related procedures.
• Subjects of childbearing potential (SOCBP) must have a negative pregnancy test prior to enrollment and be using an adequate method of contraception to avoid pregnancy throughout study participation to minimize the risk of pregnancy. Prior to study enrollment, subjects of childbearing potential must be advised of the importance of avoiding pregnancy during trial participation and the potential risk factors for an unintentional pregnancy.
• Patients must undergo a baseline physical therapy evaluation prior to axillary lymph node dissection.
• Patients who have received neoadjuvant chemotherapy are required to see physical therapy for lymphedema assessment following completion of chemotherapy prior to surgery.

Exclusion Criteria:

• Patients with history of ipsilateral breast cancer (invasive or ductal carcinoma in situ (DCIS))
• Patients with history of prior ipsilateral axillary surgery, such as excisional biopsy of lymph nodes or treatment of benign axillary disease processes such as hidradenitis
• Patients with history of or concurrent diagnosis of contralateral breast cancer (bilateral breast cancer)
• Patients with planned contralateral axillary surgery or history of contralateral axillary surgery
• Patients with a history, or concurrent, malignancy of the ipsilateral upper extremity- i.e. skin cancer
• Patients with history of lymphedema or lymphatic dysmotility of the ipsilateral or contralateral arm or are found to have lymphatic dysfunction at their pre-operative visit
• Patients with history of upper extremity blood clot, lymphangitis/cellulitis
• Patients with history of congestive heart failure or significant cardiac disease (such as New York Heart Association Class III or greater cardiac disease) including pacemakers incompatible for bioimpedance
• Patients with evidence of liver dysfunction including diagnosis of end stage liver disease
• Patients with less than 10 lymph nodes removed if no neoadjuvant chemotherapy (NAC) received, or less than 8 lymph nodes if NAC received. These node counts include nodes harvested as part of sentinel lymph node biopsy
• There is a lack of description of intraoperative findings during axillary lymph node dissection, such as the absence of notes on anatomy and procedure.
• Patients who are confirmed to be pregnant or breastfeeding.
• History of any other disease, metabolic dysfunction, clinical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicates the use of protocol therapy or that might affect the interpretation of the results of the study or that puts the subject at high risk for treatment complications, in the opinion of the treating physician.
• Prisoners or subjects who are involuntarily incarcerated, or subjects who are compulsorily detained for treatment of either a psychiatric or physical illness.