Furthermore, the residence time of Tc-99m DPD was greater than that of blue dye, which rapidly exited the lymph nodes [6]. During the immunohistochemical analysis, we sought to confirm that the nodes harvested under Tc-99m diphosphonate guidance were sentinel. mean percentages of lymphoid cells that stained positively for S-100 or CD83 were lower in sentinel lymph nodes than in non-sentinel lymph nodes (1.5% vs. 9.0% for S-100, and 4.5% vs. 9.3% for CD83, respectively, p = 0.0286). The mean percentages of lymphoid cells in sentinel lymph nodes and non- sentinel lymph nodes expressing CD1a were 3.3% and 7.0%, respectively (p = ns). == Conclusions == Tc-99m diphosphonate can reliably detect regional lymph nodes in breast cancer. Keywords:Tc-99m diphosphonate, Sentinel node, Breast cancer == Introduction == Axillary lymph node visualization is a common bone scintigraphy finding whenever bone tracer is extravasated in the ipsilateral upper extremity. The frequency of axillary lymph node visualization in routine bone scintigraphy has been reported to be 2% for Tc-99m methylene diphosphonate (MDP). The advantage of Tc-99m MDP in terms of lymph node uptake and bone visualization was first reported by Boxen [1], who suggested the use of Tc-99m diphosphonate for lymphoscintigraphy (Fig.1and2). == Fig. 1. == Lymphoscintigraphy after a subareolar injection of Tc-99m diphosphonate depicted a focal hot activity (SLN: ) other than the injection site () within 15 min of injection in anterior (a) and right lateral views (b). Anatomic information was also provided at 15 h post-injection in anterior (c) and right lateral views (d) due to spontaneous absorption of Tc-99m diphosphonate by bone == Fig. 2. == Immunohistochemical analysis was performed with antibodies to S-100 (a,b), CD83 (c,d), and CD1a (e,f) in sentinel lymph nodes (SLNs) (a,c,e) and non-sentinel lymph nodes (non-SLNs) (b,d,f). Lesser numbers of S-100- and CD83-positive cells were observed in SLNs (aandc) than in non-SLNs (bandd) Sentinel lymph Rabbit Polyclonal to HOXA11/D11 node biopsy has been widely performed in patients with breast cancer to minimize complications of routine axillary lymph node dissection. Agents used to detect sentinel lymph nodes have included blue dyes or radiopharmaceuticals. The most commonly used radiopharmaceuticals in Europe and the US are radiolabeled colloids, such as Tc-99m sulfur colloid, Tc-99m antimony trisulfide colloid (ASC), and Tc-99m nanocolloidal albumin [2]. Unfortunately, these radiopharmaceuticals are not always available in Asia. Other proposed radiopharmaceuticals include Tc-99m-labeled dextran, Tc-99m hydroxy ethyl starch, Tc-99m human serum albumin (HSA), Tc-99m stannous phytate, and Tc-99m human polyclonal immunoglobulin G (HIG) [2,3]. However, commonly available and inexpensive Tc-99m diphosphonate has never been evaluated for sentinel lymph node mapping despite Boxens suggestion. Sentinel lymph node biopsy studies have generally been conducted, based on the assumption that lymph nodes detected by blue dye or radiopharmaceuticals are sentinel L-685458 [4,5]. However, recent immunohistochemical studies have stressed several characteristics of sentinel lymph nodes [6]. Sentinel lymph nodes are the first lymph nodes that receive lymph from a primary tumor and thus are most susceptible to metastasis. Furthermore, because lymph nodes closer to a cancer are immunosuppressed by cancer-derived products, this susceptibility is further increased [7]. These immunosuppressed sentinel lymph nodes have reduced paracortical areas and dendritic cell densities [8,9]. Moreover, mature dendritic cell densities decreased in sentinel lymph nodes, while immature dendritic cell densities increased. Therefore, the purpose of this study was to evaluate the potential of Tc-99m diphosphonate as a tracer for sentinel lymph node mapping in breast cancer by analyzing its identification rate and to confirm these findings by performing immunohistochemical studies. == Materials and Methods L-685458 == == Patients == Thirty-five patients with a clinical diagnosis of T1N0 or T2N0 breast cancer were prospectively enrolled from October 2007 to December 2008. The study was approved by the institutional review board for human research L-685458 of Kyung Hee University Neo-Medical Center, and informed consent was obtained from all patients. Patients with palpable axillary lymph nodes, regional and/or distant metastasis by radiological studies, such as ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography with fluorine-18-fluorodeoxyglucose (FDG PET), were excluded, as were patients with a multifocal tumor or medical history of previous chemotherapy. All of these 35 patients were initially enrolled and underwent early lymphoscintigraphic imaging. However, three L-685458 patients were not available.
Furthermore, the residence time of Tc-99m DPD was greater than that of blue dye, which rapidly exited the lymph nodes [6]