Letter from the Editors

Article Outline

• Copyright

This second seminar devoted to nuclear medicine techniques in the evaluation of infectious disease focuses more on the future of attacking these problems than the first issue. We move from the practical day-to-day applications of radionuclides in common infectious processes to situations in which they play a role in patients with diseases that are more difficult to diagnose and often less commonplace. Anyone who has spent time in medicine has encountered a patient with fever of unknown origin (FUO). Few things can be more perplexing, potentially more expensive to evaluate, and run the gamut from totally benign to life-threatening. Drs. Bleeker-Rovers, van der Meer, and Oyen have nicely put together a review of the potential applications of nuclear medicine techniques in patients who present with FUO. As with virtually every other condition discussed in this issue and the preceding one, there appears to be a potential role in PET imaging in helping to resolve this serious condition, where up to 50% of the patients remain without a definitive diagnosis.

From FUO, we move to an equally difficult and perplexing situation—the diagnosis of opportunistic infection. This review by Drs. O'Doherty, Barrington, and Klein illustrates the extensive problems that can be associated with immunocompromised patients. To clarify this situation for the reader, they have put together an excellent group of illustrative cases that run the gamut of various pathologies. A review of their carefully thought out tables and illustrations truly provides a unique perspective for the nuclear medicine physician faced with helping the clinician reach a diagnosis in an immunocomprised patient. Drs. Ben-Haim, Gacinovic, and Israel review an area that we don't often think of in terms of infection but one that also is extremely important, life-threatening, and continues to present problems associated with diseases such as diabetes. Cardiovascular infection and inflammation are extremely life-threatening. The diagnosis can be difficult to reach and yet many very successful therapies are available to us. Here to, as in the other conditions, positron emission tomography/computed tomography (PET/CT) and single-photon emission computed tomography/computed tomography (SPECT/CT) hybrid imaging devices appear to be making significant inroads by providing us with anatomic as well as functional information to help localize and characterize the disease.

Although we have reviewed the diagnostic approaches to a number of important infectious disease processes, there are a number of new approaches that are allowing us to extend our area of utility into the cardiovascular and abdominal systems, as well as in patients with postoperative infections. Drs. Petruzzi, Shanthly, and Thakur review for us recent trends in soft tissue infection imaging, which although they overlap with many of the infectious and inflammatory processes already discussed, need to be approached with a somewhat different perspective to provide the best possible aid to the treating physician.

Drs. Basu, Zhuang, Torigian, Rosenbaum, Chen, and Alavi then take us the final step, as we move from diseases that are based primarily on problems caused by infectious agents to those diseases that are of an inflammatory and often autoimmune nature. Although the overlap between infection and inflammation is discussed repeatedly throughout this issue, this article looks at these conditions solely from the point of view of inflammation, reviewing diseases such as sarcoidosis, atherosclerosis, inflammatory bowel disease, and rheumatoid and degenerative joint disease and the approach to their diagnosis. In many cases, the distinction between an inflammatory process and an infective process may be extraordinarily difficult. The authors acknowledge that although it may not be possible to make an absolute distinction between the two in many clinical situations, the ability to detect an inflammatory process and point to a site of potential biopsy often can allow the physician to take the next definitive step and biopsy the inflamed area to make an absolute diagnosis. They also mention FUO because this may often be strictly an inflammatory rather than an infectious process, and they include atherosclerosis as well, overlapping with the article on cardiovascular disease, again because there is an overlap between inflammation and atherosclerosis. These overlapping topics have always been encouraged by the editors as they provide the reader with an opportunity to look at nuclear medicine techniques and their applications from several points of view and provide a broader perspective on how to approach any given clinical situation.

Finally, we change our pace and switch from the diagnosis of infectious and inflammatory disease to treatment. Drs. Dadachova and Casadevall have been pioneers in the applications of nuclear medicine techniques to radioimmunotherapy of infectious disease. Here, they present an approach that can be used in patients in whom antibiotic resistance has occurred or in patients with diseases where there simply is no appropriate antibiotic to use for treatment. Radioimmunotherapy is one of the dreams of nuclear medicine and although much of the initial work was directed at radioimmunotherapy of cancer, another extremely important application is radioimmunotherapy of infectious diseases. Drs. Dadachova and Casadevall discuss a wide variety of diseases and potential therapeutic agents that will surely become available over the next several years.

This issue concludes our double-issue journey through infectious and inflammatory diseases. When the editors were considering this as a topic, we were not sure that this was an appropriate area for Seminars in Nuclear Medicine. However, as we delved more into the subject and sought advice from experts in the field, including Drs. Christopher Palestro and Abass Alavi, it became clear not only that there is a huge amount of material and many potential applications for nuclear medicine in this area, but that in fact there was so much that it would require two issues of Seminars. This seminar is truly a glimpse into where nuclear medicine is heading in the future.