Failure predictors of the sentinel lymph node in patients with breast cancer using Tc-99m sulfur colloid and periareolar injection.

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.

Identification of sentinel node in breast cancer: comparison between peritumoral and periareolar injection of the radiopharmaceutical contrast medium.

Axillary node status is the most important prognostic factor for patients with primary breast carcinoma. The sentinel node biopsy (SN) technique has received much attention as a possible alternative to axillary lymph node dissection. The aim of this study is to identify the sentinel node by periareolar and subdermal injection of the radiopharmaceutical in four points, independent of tumor topography and the presence of biopsies and/or previous surgery. The peritumoral injection technique was carried out for comparison purposes. This study was performed on 115 patients, divided into 2 groups: Group A (25 patients, peritumoral injection) and Group B (90 patients, injection in four points). All the SN biopsies were studied by both imprint cytology and H&E staining. Control axillary lymph-node dissection was followed in all patients from Group A and in these positive cases from Group B. Twenty-two out of the twenty-five (88%) SNs were identified in Group A. There was no false negative; the sensitivity and specificity were 100%. Eighty-two of the ninety (91.1%) SNs were identified in Group B. Lymphoscintigraphy showed radiopharmaceutical migration to axilla in 93.7% of the cases. Hotspot area was 10 to 100 times the intensity of the background radiation. Among the 92 cases with negative sentinel nodes at intraoperative examination (TP), the SN histopathology confirmed the absence of cancer cells in 89 patients, whereas 3 were positive for metastatic cells. This study shows that periareolar injection in four points seems to be a good lymphatic mapping method for SN identification. We suggest standardizing this site of injection to identify the SNs. More studies to confirm these findings are ongoing.