Discriminating infection from sterile inflammation: can radiolabelled antibiotics solve the problem?

Excerpt

Scintigraphic imaging of infection and inflammation has been an important field in nuclear medicine for decades. If inflammation is defined as the response of the host to tissue injury irrespective of the cause of this process (micro-organisms, trauma, tumour, etc.), it is the case that all widely available radiopharmaceuticals, such as ⁶⁷Ga citrate, radiolabelled leucocytes and antigranulocyte monoclonal antibodies, and more recently [¹⁸F]fluorodeoxyglucose (FDG), are able to depict the inflammatory response of the host [1]. In many clinical situations, it is sufficient to identify a focus irrespective of its cause, as this serves to guide the use of other diagnostic techniques in order to achieve a final diagnosis. Infection can be considered a special subcategory of inflammatory disease, i.e. an inflammatory reaction of the host in response to invasion by micro-organisms. In many cases it is very important for clinical decision-making and treatment planning not only to determine whether or not there is an inflammatory response, but also to discriminate between infectious and sterile causes of the inflammation. For example, it is important to discriminate between sterile inflammation in the course of normal wound healing and postsurgical infection, and between sterile and infectious loosening of joint replacements [2, 3]. Although conventional radiopharmaceuticals do have merits in enabling such distinctions to be made, an imaging modality based on actual targeting of the causative micro-organism is probably better suited to identifying or excluding infection. …