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1.
Glucagon-like peptide-1 receptor imaging for the localisation of insulinomas: a prospective multicentre imaging study.
Christ, E, Wild, D, Ederer, S, Béhé, M, Nicolas, G, Caplin, ME, Brändle, M, Clerici, T, Fischli, S, Stettler, C, et al
The lancet. Diabetes & endocrinology. 2013;(2):115-22
Abstract
BACKGROUND Small benign insulinomas are hard to localise, leading to difficulties in planning of surgical interventions. We aimed to prospectively assess the insulinoma detection rate of single-photon emission CT in combination with CT (SPECT/CT) with a glucagon-like peptide-1 receptor avid radiotracer, and compare detection rates with conventional CT/MRI techniques. METHODS In our prospective imaging study, we enrolled adults aged 25-81 years at centres in Germany, Switzerland, and the UK. Eligible patients had proven clinical and biochemical endogenous hyperinsulinaemic hypoglycaemia and no evidence for metastatic disease on conventional imaging. CT/MRI imaging was done at referring centres according to standard protocols. At three tertiary nuclear medicine centres, we used whole body planar images and SPECT/CT of the abdomen up to 168 h after injection of (111)In-[Lys40(Ahx-DTPA-(111)In)NH2]-exendin-4 ((111)In-DTPA-exendin-4) to identify insulinomas. Consenting patients underwent surgery and imaging findings were confirmed histologically. FINDINGS Between Oct 1, 2008, and Dec 31, 2011, we recruited 30 patients. All patients underwent (111)In-DTPA-exendin-4 imaging, 25 patients underwent surgery (with histological analysis), and 27 patients were assessed with CT/MRI. (111)In-DTPA-exendin-4 SPECT/CT correctly detected 19 insulinomas and four additional positive lesions (two islet-cell hyperplasia and two uncharacterised lesions) resulting in a positive predictive value of 83% (95% CI 62-94). One true negative (islet-cell hyperplasia) and one false negative (malignant insulinoma) result was identified in separate patients by (111)In-DTPA-exendin-4 SPECT/CT. Seven patients (23%) were referred to surgery on the basis of (111)In-DTPA-exendin-4 imaging alone. For 23 assessable patients, (111)In-DTPA-exendin-4 SPECT/CT had a higher sensitivity (95% [95% CI 74-100]) than did CT/MRI (47% [27-68]; p=0.011). INTERPRETATION (111)In-DTPA-exendin-4 SPECT/CT could provide a good second-line imaging strategy for patients with negative results on initial imaging with CT/MRI. FUNDING Oncosuisse, the Swiss National Science Foundation, and UK Department of Health.
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2.
Molecular imaging in thyroid cancer.
Heston, TF, Wahl, RL
Cancer imaging : the official publication of the International Cancer Imaging Society. 2010;(1):1-7
Abstract
Molecular imaging plays an important role in the evaluation and management of thyroid cancer. The routine use of thyroid scanning in all thyroid nodules is no longer recommended by many authorities. In the initial work-up of a thyroid nodule, radioiodine imaging can be particularly helpful when the thyroid stimulating hormone level is low and an autonomously functioning nodule is suspected. Radioiodine imaging can also be helpful in the 10-15% of cases for which fine-needle aspiration biopsy is indeterminate. Therapy of confirmed thyroid cancer frequently involves administration of iodine-131 after surgery to ablate remnant tissue. In the follow-up of thyroid cancer patients, increased thyroglobulin levels will often prompt the empiric administration of 131I followed by whole body radioiodine imaging in the search for recurrent or metastatic disease. 131I imaging of the whole body and blood pharmacokinetics can be used to determine if higher doses of 131I can be given in thyroid cancer. The utility of [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) is steadily increasing. FDG is primarily taken up by dedifferentiated thyroid cancer cells, which are poorly iodine avid. Thus, it is particularly helpful in the patient with an increased thyroglobulin but negative radioiodine scan. FDG PET is also useful in the patient with a neck mass but unknown primary, in patients with aggressive (dedifferentiated) thyroid cancer, and in patients with differentiated cancer where histologic transformation to dedifferentiation is suspected. In rarer types of thyroid cancer, such as medullary thyroid cancer, FDG and other tracers such as 99mTc sestamibi, [11C]methionine, [111In]octreotide, and [68Ga]somatostatin receptor binding reagents have been utilized. 124I is not widely available, but has been used for PET imaging of thyroid cancer and will likely see broader applicability due to the advantages of PET methodology.
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3.
Roles of nuclear cardiology, cardiac computed tomography, and cardiac magnetic resonance: assessment of patients with suspected coronary artery disease.
Berman, DS, Hachamovitch, R, Shaw, LJ, Friedman, JD, Hayes, SW, Thomson, LE, Fieno, DS, Germano, G, Slomka, P, Wong, ND, et al
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2006;(1):74-82
Abstract
Noninvasive cardiac imaging is now central to the diagnosis and management of patients with known or suspected chronic coronary artery disease (CAD). Although rest echocardiography has become the most common of the techniques, nuclear cardiology and more recently cardiac computed tomography (CCT) and cardiac magnetic resonance (CMR) play important roles in this regard. This review examines the current applications and interactions of noninvasive cardiac imaging approaches for the assessment of patients with suspected CAD. In addition to considering the strengths and weaknesses of each technique, this review attempts to provide a guide to the selection of a test (or tests) that is based on the question being asked and the ability of each test to answer this question. In patients with suspected CAD, the pretest likelihood of disease, a clinical assessment, becomes the most important determinant of the initial test. If the likelihood is very low, no testing is needed. However, if the likelihood is low, recent data suggest that assessment of early atherosclerosis is likely to be the most useful and cost-effective test. In patients who have an intermediate likelihood of CAD, nuclear cardiology with myocardial perfusion SPECT (MPS) becomes highly valuable; however, coronary CT angiography (CTA), with fast 16-slice or greater scanners, may emerge as the initial test of choice. MPS would then be used if the CTA is inconclusive or if there is a need to assess the functional significance of a stenosis defined by CTA. Coronary CTA, however, is not yet widely available and is limited in patients with dense coronary calcification. In older patients with a high likelihood of CAD, MPS may be the initial test of choice, since a high proportion of these patients have too much coronary calcium to allow accurate assessment of the presence of coronary stenoses. PET/CT or SPECT/CT could emerge as important modalities combining the advantages of each modality. While CMR has great promise as a radiation-free and contrast-free "one-stop" shop, it currently lags behind CTA for noninvasive coronary angiography. Nonetheless, CMR clearly has the potential for this application and has already emerged as a highly effective method for assessing ventricular function, myocardial mass, and myocardial viability, and there is increasing use of this approach for clinical rest and stress perfusion measurements. CMR is particularly valuable in distinguishing ischemic from nonischemic cardiomyopathy. While CT and CMR are likely to grow considerably in diagnostic evaluation over the next several years, MPS and PET will continue to be very valuable techniques for this purpose.
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4.
PET and SPECT for detection of tumor progression in irradiated low-grade astrocytoma: a receiver-operating-characteristic analysis.
Henze, M, Mohammed, A, Schlemmer, HP, Herfarth, KK, Hoffner, S, Haufe, S, Mier, W, Eisenhut, M, Debus, J, Haberkorn, U
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2004;(4):579-86
Abstract
UNLABELLED Differentiation between tumor progression and radiation necrosis is one of the most difficult tasks in oncologic neuroradiology. Functional imaging of tumor metabolism can help with this task, but the choice of tracer is still controversial. This prospective study following up irradiated low-grade astrocytoma (LGA) was, to our knowledge, the first receiver-operating-characteristic (ROC) analysis that intraindividually evaluated the diagnostic performance of the SPECT tracers 3-[(123)I]iodo-alpha-methyl-L-tyrosine (IMT) and (99m)Tc(I)-hexakis(2-methoxyisobutylisonitrile) (MIBI) and the PET tracer (18)F-FDG. METHODS We examined 17 patients, initially with histologically proven LGA and treated by stereotactic radiotherapy, who presented with new gadolinium-diethylenetriaminepentaacetic acid-enhancing lesions (n = 26) on MRI. At that time, MRI could not differentiate between progressive tumor and nonprogressive tumor. This MRI examination was closely followed by (18)F-FDG PET and by (99m)Tc-MIBI and (123)I-IMT SPECT. Lesions were classified as progressive tumor (n = 17) or nonprogressive tumor (n = 9) on the basis of prospective follow-up (through clinical examination, MRI, and proton MR spectroscopy) for 26.6 +/- 6.6 mo after PET or SPECT. RESULTS (123)I-IMT yielded the best ROC characteristics and was the most accurate for classification, with an area under the ROC curve (A(z)) of 0.991. The A(z) of (18)F-FDG (0.947) was not significantly lower than that of (123)I-IMT. The difference in the A(z) of (99m)Tc-MIBI (0.713) from the A(z) of the other tracers used in our study was highly significant (P ≤ 0.01). (99m)Tc-MIBI SPECT was of low accuracy and, especially, of poor sensitivity even at modest specificity values. CONCLUSION (123)I-IMT SPECT imaging of amino acid transport accurately detects tumor progression in patients with irradiated LGA. In contrast to (123)I-IMT, (18)F-FDG PET was slightly less accurate for classification, and (99m)Tc-MIBI SPECT was of limited value. Imaging of amino acid transport with (123)I-IMT is a valuable additional tool for the follow-up of LGA, allowing early, noninvasive differentiation of lesions with ambiguous morphology after irradiation.
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5.
Comparison of O-(2-18F-fluoroethyl)-L-tyrosine PET and 3-123I-iodo-alpha-methyl-L-tyrosine SPECT in brain tumors.
Pauleit, D, Floeth, F, Tellmann, L, Hamacher, K, Hautzel, H, Müller, HW, Coenen, HH, Langen, KJ
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2004;(3):374-81
Abstract
UNLABELLED The aim of this study was to compare PET with O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) and SPECT with 3-(123)I-iodo-alpha-methyl- L-tyrosine ((123)I-IMT) in patients with brain tumors. METHODS Twenty patients with a suspected brain tumor were investigated by (18)F-FET PET, (123)I-IMT SPECT, and MRI within 3 wk. Region-of-interest analyses were performed on coregistered PET/SPECT/MRI images and the tumor-to-brain ratio (TBR), muscle-to-brain ratio (MBR), cerebellum-to-brain ratio (CerBR), and sinus-to-brain ratio (SBR) were calculated. In addition, the presence of tumor and the discrimination of anatomic structures on (18)F-FET PET and (123)I-IMT SPECT images were visually determined by 3 observers who were unaware of clinical data. RESULTS The TBR of (18)F-FET and (123)I-IMT uptake in cerebral tumors showed a highly significant correlation (r = 0.96; P < 0.001). In the visual analysis for the presence or absence of tumors, no differences for (123)I-IMT SPECT and (18)F-FET PET were found in 19 of 20 patients; in one patient a low-grade glioma was only identified on (18)F-FET PET images but not on (123)I-IMT SPECT images. The contrast between tumor and normal brain was significantly higher in (18)F-FET PET (TBR, 2.0 +/- 0.9) than in (123)I-IMT SPECT (TBR, 1.5 +/- 0.5). The discrimination of anatomic structures yielded a significantly better score on (18)F-FET PET images (rating score, 2.6 +/- 0.9) compared with (123)I-IMT SPECT images (rating score, 1.7 +/- 0.9). The uptake of (18)F-FET in the muscles was significantly higher compared with (123)I-IMT (MBR (18)F-FET, 1.4 +/- 0.3; MBR (123)I-IMT, 0.6 +/- 0.2; P < 0.001) and (18)F-FET demonstrated a significantly higher blood-pool radioactivity than (123)I-IMT (SBR (18)F-FET, 1.3 +/- 0.2; SBR (123)I-IMT, 0.8 +/- 0.2; P < 0.001). CONCLUSION The significant correlation of the TBRs of (18)F-FET and (123)I-IMT indicates that clinical experiences of brain tumor diagnostics with (123)I-IMT SPECT might be valid for (18)F-FET PET although substantial differences of the physiologic behavior were identified in extracerebral tissue. As (18)F-FET PET allows improved discrimination of anatomic structures and the tumor-to-brain contrast was significantly superior compared with (123)I-IMT SPECT scans, the results are encouraging for further evaluation of (18)F-FET for imaging brain tumors.
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6.
Use of stereotactic PET images in dosimetry planning of radiosurgery for brain tumors: clinical experience and proposed classification.
Levivier, M, Massager, N, Wikler, D, Lorenzoni, J, Ruiz, S, Devriendt, D, David, P, Desmedt, F, Simon, S, Van Houtte, P, et al
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2004;(7):1146-54
Abstract
UNLABELLED We developed a technique that allows the routine integration of PET in stereotactic neurosurgery, including radiosurgery. We report our clinical experience with the combined use of metabolic (i.e., PET) and anatomic (i.e., MRI and CT) images for the radiosurgical treatment of brain tumors. We propose a classification describing the relative role of the information provided by PET in this multimodality image-guided approach. METHODS Between December 1999 and March 2003, 57 patients had stereotactic PET as part of their image acquisition for the planning of gamma knife radiosurgery. Together with stereotactic MRI and CT, stereotactic PET images were acquired on the same day using either (18)F-FDG or (11)C-methionine. PET images were imported in the planning software for the radiosurgery dosimetry, and the target volume was defined using the combined information of PET and MRI or CT. To analyze the specific contribution of the PET findings, we propose a classification that reflects the strategy used to define the target volume. RESULTS The patients were offered radiosurgery with PET guidance when their tumor was ill-defined and we anticipated some limitation of target definition on MRI alone. This represents 10% of the radiosurgery procedures performed in our center during the same period of time. There were 40 primary brain lesions, 7 metastases, and 10 pituitary adenomas. Abnormal PET uptake was found in 62 of 72 targets (86%), and this information altered significantly the MRI-defined tumor in 43 targets (69%). CONCLUSION The integration of PET in radiosurgery provides additional information that opens new perspectives for the optimization of the treatment of brain tumors.
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7.
18F-FDG PET of patients with Hürthle cell carcinoma.
Lowe, VJ, Mullan, BP, Hay, ID, McIver, B, Kasperbauer, JL
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2003;(9):1402-6
Abstract
UNLABELLED Hürthle cell carcinoma is an uncommon differentiated thyroid cancer characterized by an aggressive clinical course and low avidity for (131)I. Treatment usually involves an aggressive surgical approach often combined with (131)I. (18)F-FDG PET has been helpful in the staging and evaluation of many types of aggressive malignancy. No reports to date have described the utility of PET in a series of patients with Hürthle cell cancer. We reviewed our experience with (18)F-FDG PET in the care of patients with Hürthle cell carcinoma to determine the likelihood of uptake in these cancers and the effect of (18)F-FDG PET on patient care. METHODS Patients with Hürthle cell cancer who were seen between June 2000 and April 2002 and were imaged with (18)F-FDG PET were included. Imaging and clinical data were reviewed. PET results were compared with the results of anatomic imaging (CT, sonography, or MRI) and (131)I imaging when performed. Patient charts were reviewed to identify any change in management that resulted from the (18)F-FDG PET findings. RESULTS Fourteen (18)F-FDG PET scans of 12 patients were obtained in the time frame indicated. All patients had documented Hürthle cell carcinoma. PET showed intense (18)F-FDG uptake in all known Hürthle cell cancer lesions but one. PET showed disease not identified by other imaging methods in 7 of the 14 PET scans. PET identified distant metastatic disease (5) or local disease (2) that was more extensive than otherwise demonstrated. In 7 of the 14 scans, the information provided by PET was used to guide or change therapy. CONCLUSION Hürthle cell carcinoma demonstrates intense uptake on (18)F-FDG PET images. PET improves disease detection and disease management in patients with Hürthle cell carcinoma relative to anatomic or iodine imaging. (18)F-FDG PET should be recommended for the evaluation and clinical management of patients with Hürthle cell carcinoma.
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8.
Measurement of the extracellular space in brain tumors using 76Br-bromide and PET.
Bruehlmeier, M, Roelcke, U, Bläuenstein, P, Missimer, J, Schubiger, PA, Locher, JT, Pellikka, R, Ametamey, SM
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2003;(8):1210-8
Abstract
UNLABELLED Brain edema significantly contributes to the clinical course of human brain tumor patients. There is evidence that an enlargement of the extracellular space (ECS) is involved in the development of brain edema. Although T2-weighted magnetic resonance (T2-MR) images represent brain edema by its increased water content, they do not differentiate ECS enlargement from increased intracellular water content. METHODS On the basis of the known distribution of bromide in the ECS, we used (76)Br-bromide and PET to measure the regional ECS in 9 brain tumor patients. Transport rate constants and the distribution volume (DV) of (76)Br-bromide in normal brain and tumor were derived from dynamic PET scans and the measured (76)Br-bromide concentration in arterial plasma. We evaluated different models regarding their reliability in estimating the ECS. RESULTS Assuming that the DV of (76)Br-bromide represents the ECS, robust estimates were possible for all investigated regions. In normal brain, ECS was within a narrow range-for example, occipital lobe, 19.9% +/- 3.1%-and was lower in 2 dexamethasone-treated patients compared with untreated patients. In 7 of 9 tumors, increased ECS ranged between 43.8% and 61.1%. ECS increases were confined to the tumor mass and did not extend into peritumoral edematous brain. Two patients with large hyperintense lesions according to T2-MR images showed normal ECS values within the lesion. CONCLUSION (76)Br-Bromide PET allows a quantitative measurement of the ECS in brain edema and in normal brain. The discrepancies between lesions shown by T2-MRI and regional ECS enlargement as measured with PET challenge the concept of tumor-induced brain edema.
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9.
PET imaging of osteosarcoma.
Brenner, W, Bohuslavizki, KH, Eary, JF
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2003;(6):930-42
Abstract
During the past decade the clinical value of PET imaging has been investigated for many different tumors. As knowledge of the advantages and limitations of this modality increased, PET has gained acceptance in tumor imaging. (18)F-FDG PET is now successfully used and approved for procedure reimbursement in many types of cancer-for example, lung cancer, melanoma, lymphoma, head and neck tumors, brain tumors, esophageal cancer, and colorectal cancer. In osteosarcoma, the introduction of neoadjuvant chemotherapy has dramatically improved survival rates, thus changing the demands for state-of-the-art imaging to provide detailed information on tumor staging and grading, evaluating treatment, and detecting recurrences. In this review, the available literature on PET imaging in osteosarcoma patients is critically summarized with respect to diagnosis, staging, therapy monitoring, and follow-up focusing on the clinically used tracers (18)F-FDG and (18)F-fluoride ion. Potential and probable indications are outlined. Because of the relatively small number of patients enrolled in clinical trials published to date, further research needs to be done in larger, prospective patient series to determine the full utility of PET in osteosarcoma.
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10.
Nuclear medicine and infection detection: the relative effectiveness of imaging with 111In-oxine-, 99mTc-HMPAO-, and 99mTc-stannous fluoride colloid-labeled leukocytes and with 67Ga-citrate.
Hughes, DK
Journal of nuclear medicine technology. 2003;(4):196-201; quiz 203-4
Abstract
With a current annual mortality rate of around 35% worldwide, infection remains a significant concern, and the diagnosis and localization of infectious foci is an important health issue. As an established infection-imaging modality, nuclear medicine plays a vital health-care role in the diagnosis and subsequent effective treatment of this condition. Despite the development of several newer radiopharmaceuticals, (67)Ga and leukocyte imaging procedures have maintained their established place for infection. Several techniques in nuclear medicine significantly aid infection diagnosis, including imaging with (111)In-oxine-, (99m)Tc-hexamethylpropyleneamine oxime-, and (99m)Tc-stannous fluoride colloid-labeled leukocytes and with (67)Ga-citrate. Each radiopharmaceutical has specific advantages and disadvantages that make it suitable to diagnose different infectious processes (e.g., soft-tissue sepsis, inflammatory bowel disease, osteomyelitis, occult fever, fever of unknown origin, and infections commonly found in immunocompromised patients). After finishing this article, the reader should be able to identify the properties of an ideal radiopharmaceutical for infection imaging, list a range of available infection-imaging radiopharmaceuticals, compare the relative results of a range of radiopharmaceuticals used internationally to detect infection in the body, understand several common infectious processes that can be diagnosed using nuclear medicine techniques, and select an appropriate radiopharmaceutical to image a range of infectious processes.