The role of lymphoscintigraphy in the management of the patient with breast cancer

Introduction: Regional nodal status is the most powerful predictor of recur rence and survival in women with breast cancer. Lymphatic mapping and senti nel lymph node (SLN) biopsy have been found to accurately predict the regio nal nodal status. Preoperative lymphoscintigraphy has been used in melanoma patients to identify the basins at risk for metastases when primary sites are located in watershed areas of the body. This study was performed to def ine the role of lymphoscintigraphy for axillary nodal staging in women with breast cancer. Specifically. can preoperative lymphoscintigraphy define a population of women with breast cancer who have multidirectional drainage o r who do not drain to the axilla and need no axillary dissection? Methods: 516 patients with invasive breast canter were accrued in a nationa l breast lymphatic mapping trial sponsored by the U.S. Department of Defens e. Preoperative lymphoscintigraphy images were produced using filtered tech netium-99 sulfur colloid. Lymphatic drainage to axillary and internal mamma ry sites was noted. Results: Drainage to an axillary SLN was found in 335 (65%) patients, and i nternal mammary or extra-axillary drainage was noted in 52 (10%) patients. By using sensitive hand-held probes and vital blue dye intraoperatively, th e overall success rate of finding an axillary SLN was 85%. Of the 335 patie nts who had an axillary SLN identified with imaging, all had successful SLN biopsy procedures. Although no SLNs could be imaged in 181 patients, 153 ( 85%) of these patients had an axillary SLN identified with intraoperative m apping. For 28 patients in which lymphoscintigraphy was negative and intrao perative mapping was unsuccessful, complete axillary node dissection was pe rformed, and 13 (46%) of these patients were found to have metastatic disea se in the basin. Conclusions: Preoperative Lymphoscintigraphy can identify those women with primary breast cancers who have extra-axillary regional basin drainage such as internal mammary. The ability to image an axillary. SLN was associated with a high success rate of being able to find the node intraoperatively wi th a combination mapping technique. In a high percentage of patients with n egative lymphoscintigraphy. the SLN was identified with more sensitive hand -held probes. Therefore, patients who have a negative preoperative lymphosc intigraphy and intraoperatively are found to have no "hot" spot in the axil la with the hand-held probe still need an axillary node dissection, because 46% of these patients contain metastatic disease in the axilla.