Nuclear Medicine in the Imaging and Management of Breast Cancer

Axillary nodal status is the most important prognostic factor for patients with breast cancer. Clinical assessment and imaging modalities are not always reliable. Surgical removal and histopathological examination of axillary lymph nodes remain essential methods of staging the axilla and planning breast cancer therapy (Chu et al, 2010; Perry, 2001) But whether axillary lymph node dissection improves survival remains controversial. Historically, nodal involvement was determined by conventional axillary dissection. (Gill, 2009) Till 1990s conventional axillary dissection was performed in all women with breast cancer with great incidence of morbidities such as pain, numbness, shoulder joint stiffness, scarring, infection and long term lymphoedema. (Mansel et al, 2006) Sentinel lymph node biopsy has recently been introduced in the treatment of women with breast cancer. The American Society of Clinical Oncology in 2005 (Lyman, 2005), and more recently the British Association of Surgical Oncology (Association of Breast Surgery, 2009) endorsed sentinel lymph node biopsy (SLNB) as the recommended method of staging early breast cancer in clinically node negative patients. The sentinel lymph node hypothesis is that the sentinel lymph nodes are the first nodes draining a tumor and that focused histological analysis of sentinel lymph nodes is predictive of the status of the regional nodes thus accurately staging the breast disease with lower incidence of complications. (Krag et al, 1998; Morton et al, 1992) Giuliano et al (Giuliano et al, 1994) demonstrated that the status of sentinel nodes, with respect to the presence of metastases, accurately reflected the metastatic content of the local nodal basin. Early works support the feasibility and accuracy of sentinel lymph node biopsy. However, the optimal management of the axilla remains uncertain as axillary lymph node dissection, sentinel lymph node biopsy and lymphoscintigraphy have been described as reliable alternative procedures. By combining preoperative lymphatic mapping with intraoperative gamma probe detection nuclear medicine procedures are increasingly used to identify and detect the sentinel node in breast cancer, and in other malignancies.