RESUMO
AIM: As sentinel lymph node (SLN) experience rises, it is important to identify factors that can limit lymphoscintigraphic mapping. METHODS: A prospective study was conducted with breast cancer patients that were submitted to sentinel node mapping by lymphoscintigraphy between October 2003 and January 2005. The analyzed factors were: patients' age, body mass index, tumor size, previous breast surgeries, time between a previous biopsy and the radiotracer injection and their impact on preoperative SLN identification. RESULTS: Two hundred and three breast cancer patients were injected with (99m)Technetium-sulfur colloid and submitted to lymphoscintigraphy scan for SLN biopsy. One hundred and eighty-four of these patients (90.64%) had a successfully identified SLN and 19 (9.36%) had a mapping failure. The median age of the successful group was 55.6 years and in the failure group was 57.1 years (P=0.002). The median body mass index was 25.3 and 27.6, respectively (P=0.024). The tumor size did not show any significant difference between the patients with successful mapping and failure (P=0.07). Previous breast surgery was an important limiting factor for SLN mapping (P=0.017). The mean time from biopsy to SLN detection was 23.6 days on the successfully marked patients and 17.4 days in the failure group (P<0.0001). All the 184 successfully mapped patients had the SLN identified. Only one patient of the failure group had the SLN identified using blue dye. CONCLUSION: Advanced age, elevated body mass index, previous breast surgery and a shorter period of time after a breast biopsy are causes for SLN identification failure. The tumor size was not a limiting factor.
