Purpose
The accurate harvesting of a sentinel node in breast cancer includes a sequence of procedures with components from different medical specialities, including nuclear medicine, radiology, surgical oncology and pathology. The aim of this document is to provide general information about sentinel lymph node detection in breast cancer patients.

The EANM and SNMMI practice guideline for lymphoscintigraphy and sentinel node localization in breast cancer

The contrast mechanisms used for photoacoustic tomography (PAT) and fluorescence imaging differ in subtle, but significant, ways. The design of contrast agents for each or both modalities requires an understanding of the spectral characteristics as well as intra- and intermolecular interactions that occur during formulation. We found that fluorescence quenching that occurs in the formulation of near-infrared (NIR) fluorescent dyes in nanoparticles results in enhanced contrast for PAT. The ability of the new PAT method to utilize strongly absorbing chromophores for signal generation allowed us to convert a highly fluorescent dye into an exceptionally high PA contrast material. Spectroscopic characterization of the developed NIR dye-loaded perfluorocarbon-based nanoparticles for combined fluorescence and PA imaging revealed distinct dye-dependent photophysical behavior. We demonstrate that the enhanced contrast allows detection of regional lymph nodes of rats in vivo with time-domain optical and photoacoustic imaging methods. The results further show that the use of fluorescence lifetime imaging, which is less dependent on fluorescence intensity, provides a strategic approach to bridge the disparate contrast reporting mechanisms of fluorescence and PA imaging methods.

http://oilab.seas.wustl.edu/epub/2011/AkersW_2011_ACS%20Nano_v5_p173.pdf

Noninvasive Photoacoustic and Fluorescence Sentinel Lymph Node Identification using Dye-Loaded Perfluorocarbon Nanoparticles

More than 210,000 Americans will be diagnosed with breast cancer each year and more than 41,000 will die from this disease. Over the last two decades many novel therapies have been introduced. However, due to the limited availability and accuracy of prognostic and predictive markers, many patients will have to be treated for the benefit of a few. The lack of precise predictive markers not only pertains to the use of chemotherapy, but also to hormonal or targeted therapy. Still more than half of the patients treated will not derive a benefit. Currently, the prognosis and treatment plan for early stage breast cancer is based on the number of involved lymph nodes, the size of the tumor, the histological grade and type, as well as lymphatic and vascular invasion which will determine the potential benefits from adjuvant chemo- and radiation therapy. Further therapeutic intervention, targeting estrogen receptor and HER2 signaling pathways, are based on the qualitative and quantitative assessment of the estrogen receptor (ER) and progesterone receptor (PR) status and HER2 expression by immunohistochemistry or the HER2 amplification by prognostic and predictive values of gene expression patterns and the better definition of therapeutic targets will lead to significant change in the assessment and treatment of breast cancer in the near future.

In human breast cancer

Purpose
The aims of this study were (1) to evaluate FDG PET/CT and CT for the detection of axillary lymph node metastases in breast cancer (BC) patients and (2) to evaluate FDG PET/CT as a pre-test for the triage to sentinel lymph node biopsy (SLNB) versus axillary lymph node dissection (ALND).

Diagnostic value of full-dose FDG PET/CT for axillary lymph node staging in breast cancer patients.

Procedure guidelines for scintigraphic detection of sentinel node in breast cancer are presented. The paper was written by several experts in this field on behalf of the European Association of Nuclear Medicine Oncology and Dosimetry committees and approved by the Executive Committee.

/pdf/sentinel-node-in-breast-cancer-procedural-guidelines-38ft5gzrum.pdf

Sentinel node in breast cancer procedural guidelines

The status of the axilla is the single most important prognostic indicator of overall survival in patients with breast cancer. Staging is based on tumor size and on the presence of lymph node metastases. The number of lymph nodes, although prognostic, no longer impacts treatment options. Sentinel lymph node (SLN) mapping and dissection is a more sensitive and accurate technique for nodal evaluation and has been applied to staging of axillary lymph nodes in patients with breast cancer, providing prognostic information, with less surgical morbidity than with axillary lymph node dissection (ALND). When analyzed by an experienced pathologist with serial sectioning and immunohistochemical evaluation, SLN is the most accurate detection tool used in staging of breast cancer. In many centers that use these staging principles, ALND is no longer performed for histologically negative axillary SLNs. In addition, this technique may also be therapeutic because in most patients, the SLN is the only positive axillary node. SLN biopsy is justified in women with ductal carcinoma in situ who have a high risk of invasive carcinoma, such as those with large tumors, a mass, or high-grade lesions. SLN biopsy is performed in the setting of neoadjuvant chemotherapy and demonstrates accurate evaluation of the axilla in 90% of the cases. Women with locally advanced breast cancer may derive great benefit from a minimally invasive approach to the axilla because the extent of nodal involvement is unlikely to change further treatment. For clinically palpable nodes, ALND should be performed for therapeutic and local control. The use of sentinel node mapping in pregnancy is controversial. Vital blue dye is contraindicated in pregnant patients, although some have used radioactive colloid alone to map this subgroup of patients.

Farin Amersi

Papers

The benefits and limitations of sentinel lymph node biopsy