Comparison of peritumoral and subareolar injection of Tc99m sulphur colloid and blue-dye for detection of the sentinel lymph node in breast cancer.

Background: The new trend in diagnosis of the lymph node is sentinel node biopsy. This method has become increasingly accepted as a minimally invasive alternative to routine axillary dissection. Although the results of numerous studies have shown that sentinel node biopsy can accurately determine the axillary nodal status, the identification rates and false-negative rates have been variable. The sentinel lymph node is defined as the first node in the lymphatic basin that receives the primary lymphatic flow.
Material and Methods: Between September 1998 and August 2002 123 patients with primary operative breast cancer without clinical palpable axillary lymph nodes were enrolled in the study. There were two groups of patients according to sentinel node identification technique: 51 patients (Group I) received parenchymal, peritumoral injection of 1.0 ml of 16 MBq Tc(99m)-radiolabelled sulphur colloid and single intradermal injection of blue-dye over the tumour. The next 72 patients (Group II) received intradermal, periareolar one-site injection of 0.5 ml of 16 MBq Tc(99m)-radiolabelled sulphur colloid and blue-dye.
Results: Sentinel lymph node was found in 41 (80.4%) cases in Group I and in 67 (93.0%) cases in Group II (p = 0.028). The localisation of the axillary lymph node as a "hot spot" visualised by lymphoscintigraphy was successful in 39/51 (76.5%) cases in Group I and 67/72 (93.0%) in Group II, p = 0.004). In both groups the success of sentinel node identification in the axillary region by lymphoscintigraphy was connected with sentinel lymph node finding during surgery (Group I: p < 0.001, Group II: p < 0.001).
Conclusions: This study shows that intradermal, periareolar one-site injection of Tc(99m)-radiolabelled sulphur colloid and blue-dye is superior to peritumoral 4-sites injections Tc(99m)-radiolabelled sulphur colloid and single intradermal injection of blue-dye over the tumour in sentinel lymph node identification.