Letter from the Editors

Article Outline

• Copyright

This issue of Seminars in Nuclear Medicine devoted to genitourinary (GU) nuclear medicine is considerably different in content from previous GU issues. Notably missing from the Table of Contents is any review of clearance techniques and any in-depth review of radiorenography. The Editors feel that these subjects have been relatively static during the last several years and do not require a significant review at this time. Another major difference is the inclusion of an article on female genital disease that has achieved a renaissance with positron emission tomography (PET) imaging.

In a more traditional vein, there is a superb review of pediatric renal nuclear medicine by Drs. Piepsz and Ham. Any active nuclear medicine practice—whether or not it includes pediatric studies—will benefit greatly from the information in this article. Dr. Piepsz’s contributions to the field of pediatric renal nuclear medicine are voluminous and he is clearly one of the outstanding international leaders in this field. The other article directed at renal nuclear medicine in current practice is the update of renal imaging by Drs. Grenier, Hauger, Cimpeau, and Pérot. Dr. Grenier and his group have considerable experience with renal imaging and provide us with a perspective of the relative roles of nuclear medicine, magnetic resonance imaging, computed tomography (CT), and ultrasound. Considerable emphasis is given to non-nuclear techniques where the greatest changes and advances have occurred during the last several years. There is no question that changes that have occurred in conventional radiologic techniques have had, and will continue to have, a very profound impact on the practice of renal nuclear medicine. These techniques will not replace radionuclide studies, but rather will significantly alter the algorithms which determine the order in which we perform examinations in specific disease states. Much of what is contained in this article is not yet routine medical practice, but there is little question that it will be of increasing importance over the next several years.

Positron emission tomography imaging has not yet had a major impact in the study of renal disease. However, Drs. Szabo, Xia, Mathews, and Brown have pioneered a novel approach to the use of renal PET. Their work examines kidney problems, not from that of indirect evaluation of changes in function relating to renal disease, but rather through measurement of the actual biologic systems affected. It is not clear how much the material in this article will become state-of-the-art practice in renal nuclear medicine, but it clearly shows great potential. At the very least, the work described in this review will have a profound impact on the way in which we approach the investigation of renal disease. The use of PET will provide insights into mechanisms of renovascular hypertension, congestive heart failure, and the role and reaction of the kidney in a wide variety of pathophysiologic states.

Although we would not normally include a bone imaging article in a kidney issue, a reasonable justification for departure exists here. Drs. Langsteger, Heinisch, and Fogelman review bone imaging from an entirely new point of view. They suggest that PET bone studies may indeed become state-of-the-art sometime during the next decade. This prediction will depend of course on further supporting data and the ultimate cost efficacy in performing these studies. In keeping with the GU topic of this seminar, their article places an emphasis on prostate and breast disease. Although breast disease theoretically could also be considered part of genital imaging, we have chosen only to include it here from the perspective of bone PET. A recent breast PET article appeared in the July 2004 (Vol 34, No 3) issue of Seminars. In addition, a full seminar devoted to breast disease (April 2005, Vol 35, No 2) provided current general reviews of nuclear medicine’s role in breast disease.

Among the specific genital diseases that can be evaluated with nuclear medicine are those of the prostate, testes, and bladder in males and ovary, endometrium, and cervix in females. The review by Drs. Jana and Blaufox covers the prostate, testes, and bladder. The prostate, because of its importance, deserves a considerable amount of discussion. However, with the exception of the bone scan, most nuclear medicine procedures related to the prostate have been somewhat disappointing. This includes Prostacint, which has failed to achieve as widespread use as its initial introduction promised. Scrotal imaging is the one area among male genital diseases where there is still a considerable amount of information to be gained. ¹⁸F-Fluorodeoxyglucose (FDG)-PET imaging in patients with testicular cancer has an important role to play in the follow-up and evaluation of testicular tumors. Bladder cancer is also included in this discussion, perhaps more because of its proximity than its direct role in the genital system. However, as is the case with some female tumors, although bladder cancer uptake of FDG is significant, there are considerable methodologic problems associated with the competing presence of FDG in the urine.

Finally, there is the article on the ovary, endometrium, and cervix by Drs. Yen and Lai. This area of PET imaging is just beginning to come into its own. Dr. Yen and her group present a very persuasive argument for the role of PET in evaluating female genital tumors, where imaging by other procedures is often very difficult.

Although we have recently abandoned the gamut section, we have chosen to include in this issue a brief report related to testicular imaging by Drs. Kuo, Cooper, and Cheng because of its relevance.

During the next several years, we will undoubtedly see the introduction of new imaging agents. A major emphasis has been placed on PET and there are likely to be several more specific agents introduced to compete with FDG. These agents will affect all nuclear medicine imaging and perhaps PET to the greatest extent. The role of PET continues to evolve into greater importance and it is likely, in the near future, that PET will become synonymous with PET/CT. Although just a few years ago an article on GU nuclear medicine might have included PET only as a research modality, it has now become integral to the practice of nuclear medicine in all areas.