Sentinel Lymph Node Imaging and Biopsy in Breast Cancer

Abstract

Enfeksiyon-Enflamasyon: Moleküler Görüntülemede Kullanılan SPECT RadyofarmasötikleriFunctional and metabolic Nuclear medicine imaging techniques demonstrate infectious as well as inflammed foci before the presence of any anatomical sign. Numerous techniques have been developed for scintigraphic visualisation of infection and inflammation for a period of more than a half century. Specific as well as nonspecific radiopharmaceuticals have been utilised. The uptake mechanisms of non-specific agents are mostly dependant on changes in vascular permeability. That's why it is not possible to distinguish infection and inlammation using non-specific agents. Ga-67 citrate can also be used for diagnosis of infection in several pathological cases. The uptake mechanism of Ga-67 citrate in infectious foci is dependent on many factors but binding to transferin in the circulating blood is the initial step. On the other hand In-111 oxin or Tc-99m labelled immunoglobulin are accumulated at the infection site with the activation of Fc-ɣ receptors in the leukocytes. Although In-111 and Tc99m labelled leukocyte scıntigraphy have been developed in the 1970s, this method has been still a golden one. As the isolation and labelling process of luekocytes is time consuming and involved some risk factors, the researches have been investigating ways to develop spesific agents which will trap in leucosite in vivo. Tc-99m and I-123 labelled antigranulocyte antibodies, peptides, cytokines, all of which will target and bind leukocyte receptors have been used to visualise infections. Additionally antibiotics and antimicrobial peptides have been labelled with radionuclides in vivo, in order to carry out spesific visualisation techniques.