We have had the privilege of previously editing single volumes of Seminars in Nuclear Medicine, but to edit a double volume seems a rare treat indeed. This provides us with the opportunity to address, in considerable depth, many of the topics that we are passionate about and that we hope will provide a source of reference, which will stand the test of time.
Nevertheless, we recognize that medicine moves forward at a rapid pace and nowhere is this more apparent than in the field of imaging. An understanding of the advantages and limitations of the modalities available will help expedite diagnosis, and hence treatment. Dr Vijayanathan and coauthors have elegantly reviewed the investigation of the musculoskeletal system by conventional radiological techniques and to be able to comprehensively cover the topics of infection, arthropathy, malignancy, and trauma is a difficult task, but one in which they have succeeded.
The use of tracer techniques to assess both global and regional skeletal metabolism is technically challenging and at present is essentially limited to research. Nevertheless, this has potentially important clinical implications, and it is hoped that in the future less complicated techniques will become available. Dr Blake and coauthors update us with regard to the current status of quantitative studies of bone using 99mTc-MDP skeletal plasma clearance.
Radionuclide scintigraphy is highly sensitive for lesion detection, but the specificity is relatively low. This limitation related to specificity can be at least partially addressed by a thorough knowledge and experience of normal variants and common disease patterns, which will often avoid misinterpretation. Dr Gnanasegaran and coauthors have described the common patterns, variants, artifacts, and pitfalls in conventional radionuclide planar, single-photon emission computed tomography (SPECT), and hybrid bone (SPECT/computed tomography [CT]) imaging with a large number of illustrative cases.
We predicted some years ago that routine bone scanning will eventually be performed using fluoride positron emission tomography (PET) scans and there is no reason to change that prediction. However, although there have been great advances in radionuclide bone imaging, there is still much that we do not fully understand. For example, how we should optimally use PET to evaluate bone metastases because several tumors, such as prostate and to a lesser extent renal cell carcinoma, show variable fluorodeoxyglucose (FDG) avidity, and the situation is further complicated even when tumors are FDG avid if a patient has previously received treatment. An important question, which has not been adequately answered, is that if a metastasis does not show FDG avidity then what are the prognostic implications for the patient and indeed does this lesion matter at all.
The use of choline continues to show promise in prostate cancer, and there will undoubtedly be further opportunities for the use of new PET tracers for specific malignancies. Dr Beheshti and coauthors have written an interesting and extensive review addressing the role of SPECT and PET in imaging bone metastases with a variety of tracers in patients with prostate cancer. From prostate cancer, we move on to another excellent review by Drs Ben-Haim and Israel, assessing the role of SPECT and PET in imaging bone metastases in patients with breast cancer. Dr Chua and coauthors provide a broad perspective of SPECT and PET imaging in miscellaneous cancers, including lung, thyroid, renal cancer, myeloma, and neuroendocrine tumors.
We believe that SPECT/CT is a significant advance in the field of bone imaging, and we are still learning its capabilities and potential applications in clinical practice. In the last article, in part I of the bone update series, Dr Gnanasegaran and coauthors have reviewed the potential application of SPECT/CT in benign and malignant bone disease with illustrative clinical examples.
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