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Objective This study aimed to (1) compare the agreement of two evaluation methods of metabolic response in patients with non-small cell lung cancer (NSCLC) and determine their prognostic value and (2) explore an optimal cutoff of metabolic reduction to distinguish a more favorable subset of responders. Methods This is a secondary analysis of prospective studies. Enrolled patients underwent 18F-PET/CT within 2 weeks before, during, and months after radiotherapy (post-RT). Metabolic response was assessed using both Peter MacCallum (PM) method of qualitative visual assessment and University of Michigan (UM) method of semiquantitative measurement. The agreement between two methods determined response, and their prediction of outcome was analyzed. Results Forty-four patients with median follow-up of 25.2 months were analyzed. A moderate agreement was observed between PM- and UM-based response assessment (Kappa coefficient = 0.434), unveiling a significant difference in CMR rate (p = 0.001). Categorical responses derived from either method were significantly predictive of overall survival (OS) and progression-free survival (PFS) (p Conclusions There was a modest discrepancy in metabolic response rates between PM and UM criteria, though both could offer predictive classification for survival. The percentage decrease provides an ordinal value that correlates with prolonged survival, recommending 75 % as the optimal threshold at identifying better responders.

Blood glucose is routinely measured prior to436 FDG PET/CT consecutive studies performed for oncology staging in 229 patients (226 male) at the Ann Arbor Veterans Administration Healthcare System were reviewed. All patients had blood glucose measured (112.4±34.1mg/dL) prior to injection of 466.2±51.8MBq (12.6±1.4mCi) of FDG. SUV measurements of brain, aortic arch blood-pool, liver, and spleen were obtained at 64.5±10.2min' post-injection.We found a negative inverse relationship of brain SUV with increasing plasma glucose, levels for both absolute and normalized (either to blood-pool or liver) values. Higher blood glucose levels had a mild effect upon liver and blood-pool SUV. By contrast, spleen SUV was independent of blood glucose, but demonstrated the greatest variability (deviation on linear regression). In contrast to other tissues, liver and spleen SUV normalized to blood-pool SUV were not dependent upon blood glucose levels.The effects of hyperglycemia upon FDG uptake in brain and liver, over a range of blood glucose values generally considered acceptable for clinical PET imaging, may have measurable effects on semi-quantitative image analysis.

The purpose of this study was to systematically review the utility of single-photon emission tomography–computed tomography (SPET–CT) fusion imaging in the investigation of thyroid cancer. We performed a systematic search of the world literature on radionuclide SPET–CT imaging of thyroid cancer using the medical databases Medline (OVID) and PubMed. The following search terms were used to identify relevant studies: (a) thyroid, combined with (b) SPECT/CT or SPECT–CT or SPET/CT or SPET–CT. The electronic searches returned citations for 1,189 potentially eligible articles and 98 abstracts were reviewed for relevance by two co-authors. Thirty-one peer-reviewed full articles reporting the utility, value and diagnostic performance of radioiodine SPET–CT for the imaging of well-differentiated thyroid cancer were selected. The quality of these studies was assessed using the quality assessment of diagnostic accuracy studies-2 tool. As there was heterogeneity in the studies, a systematic review analysis was conducted as our chosen research synthesis method. A total of 31 studies published between 2003 and 2014 report the utility of radioiodine SPET–CT. These studies uniformly found incremental diagnostic value of I-123 and I-131 SPET–CT over SPET and/or planar imaging. SPET–CT allows accurate characterization of radioiodine uptake in the neck and at distant sites, clarifies equivocal foci of radioactivity, improves specificity for disease, and evaluates benign physiological etiologies. Additional pilot uses of SPET–CT have been reported, e.g., for thyroid nodule evaluation, medullary thyroid cancer work-up, and investigation of lingual thyroid. Radioiodine SPET–CT fusion imaging of thyroid cancer has incremental utility, improving image interpretation as compared to planar and SPET imaging. It is likely to see more widespread application in the future.

The diagnosis of dementia syndromes can be challenging for clinicians, particularly in the early stages of disease. Patients with higher education levels may experience a marked decline in cognitive function before their dementia is detectable with routine testing methods. In addition, comorbid conditions (eg, depression) and the use of certain medications can confound the clinical assessment. Clinicians require a high degree of certainty before making a diagnosis of Alzheimer disease or some other neurodegenerative disorder, since the impact on patients and their families can be devastating. Moreover, accurate diagnosis is important because emerging therapeutic regimens vary depending on the cause of the dementia. Clinically based testing is useful; however, the results usually do not enable the clinician to make a definitive diagnosis. For this reason, imaging biomarkers are playing an increasingly important role in the workup of patients with suspected dementia. Positron emission tomography with 2-[fluorine-18]fluoro-2-deoxy-D-glucose allows detection of neurodegenerative disorders earlier than is otherwise possible. Accurate interpretation of these studies requires recognition of typical metabolic patterns caused by dementias and of artifacts introduced by image processing. Although visual interpretation is a vital component of image analysis, computer-assisted diagnostic software has been shown to increase diagnostic accuracy.

Summary Background To determine whether the addition of molecular and imaging biomarkers to established clinical risk factors could help predict locoregional failure (LRF) after chemoradiation in human papillomavirus (HPV)-related (+) oropharyngeal cancer (OPC) and improve patient selection for locoregional treatment de-intensification. Methods HPV status was determined for 198 consecutive patients with stage III/IV OPC treated with definitive chemoradiation from 5/2003 to 10/2010. The impact of pre-therapy epidermal growth factor receptor (EGFR) overexpression; imaging biomarkers including primary tumor and nodal maximum standardized uptake values on FDG-PET, gross tumor volumes, and matted nodes; and clinical factors on LRF (including residual disease at adjuvant neck dissection) was assessed. Results Primary tumors were HPV+ in 184 patients and HPV-negative in 14. EGFR overexpression was related to HPV-negative status and was univariately associated with LRF in the overall population, but was neither retained in the multivariate model after adjustment for HPV status, nor associated with LRF in HPV+ patients. Similarly, imaging biomarkers were univariately associated with LRF, but correlated with T-stage and/or N-stage and did not remain predictive in HPV+ patients after adjustment for T4- and N3-stages, which were the only significant predictors of LRF on multivariate analysis. Among HPV+ patients with non-T4- or N3-stages, only minimal smoking was associated with decreased LRF. Conclusions The prognostic impact of EGFR overexpression and imaging biomarkers on LRF was predominantly related to their association with HPV-negative status and T- or N-stage, respectively. Among HPV+ OPC patients treated with uniform chemoradiation, only T4-stage, N3-stage, and smoking contributed to risk-stratification for LRF.

Endocrine tumors are hormonally active benign or malignant neoplasms arising within endocrine organs or from specialized cells of the amine precursor uptake and decarboxylation system. The detection rate of these tumors is increasing as a result of sensitive biochemical tests and high-resolution diagnostic imaging. Medical imaging has become a key component in the diagnosis and staging of endocrine malignancies; however, despite the impressive advances in computed tomography (CT) and MRI, detection of small primary tumors and metastases continues to be a challenge. Functional imaging techniques use radiopharmaceuticals targeted at unique tumor cellular processes in order to provide sensitive and highly specific whole-body imaging. Functional imaging allows prediction of the efficacy of radionuclide or receptor-based therapies and surveillance after therapy. Advances in imaging have not been limited to radiopharmaceuticals. Hybrid scanner technology in the form of PET/CT and single photon emission computed tomography (SPECT)/CT, designed to combine functional images with anatomic maps, has further improved the diagnostic accuracy. High-resolution hybrid imaging when deployed with novel PET and SPECT radiopharmaceuticals has the potential to dramatically change, individualize, and optimize imaging plans based on the histological grade, degree of differentiation, and genetic profile of each patient's endocrine neoplasm.

Sites of infection and inflammation can be misleading in oncology PET/CT imaging because these areas commonly show 18F-FDG activity. Caution in the interpretation must be taken to avoid the misdiagnosis of malignancy. Utilization of both CT findings as well as patient history can help differentiate benign infectious and inflammatory processes from malignancy, although occasionally additional work-up may be required. This article discusses the mechanism of 18F-FDG uptake in infection and inflammation with illustrative examples.

Oral activity on radioiodine scintigraphy is commonly seen and may cause diagnostic dilemma. Determining the precise mechanism of oral uptake on radioiodine scintigraphy will increase the accuracy and confidence of interpretation and avoid possible misinterpretation.To determine the etiology of focal persistent radioiodine oral uptake seen on radioiodine scans.Retrospective sequential series at a university clinic and a phantom study experiment.Preablation iodine-131 planar and single photon emission computed tomography/computed tomography (SPECT/CT) scans of 216 patients after total thyroidectomy were reviewed. Planar images were inspected for the presence of oral activity above the salivary gland background and SPECT/CT was reviewed to determine the location and nature of oral activity. A post-hoc phantom study was designed using typodont stone models fitted with various dental materials, immersed in a diluted iodine-131 solution, and imaged with SPECT/CT to characterize radioiodine uptake by high-attenuation dental materials.Oral activity was seen on planar images in 123 of 216 (57%) patients; 12 patients were excluded from analysis because the SPECT/CT field of view did not cover the entire oral cavity. In the remainding 111 patients SPECT/CT images demonstrated focal uptake localizing to high-attenuation dental material on the CT in 95 of 111 (86%) patients. All cases of oral activity on planar imaging were interpreted as benign etiology on SPECT/CT. The phantom study confirmed focal in vitro uptake within high-attenuation dental materials representing a range of commonly used metal alloys.Focal oral activity on diagnostic radioiodine scans frequently localizes to high-attenuation dental material on SPECT/CT. We postulate that an affinity between negatively charged iodide ions (I(-)) in saliva and positively charged metal ions (eg, Ag(+), Hg(+), Au(2+), Pd(2+)) within the dental materials is at the basis of persistent focal radioiodine uptake in the oral cavity. This represents a new mechanism underlying benign radioiodine activity not previously described in the medical literature.

Radioiodine imaging has a well-established role in depicting metastatic disease after thyroidectomy in patients with well-differentiated thyroid cancer. Uptake of radioiodine in thyroid metastases depends on expression of sodium-iodide symporter (NIS) by tumor tissues. However, because radioiodine may also accumulate in normal structures and tissues, it is important to distinguish physiologic radioiodine activity from metastatic disease. Furthermore, secretions that contain radioiodine may also simulate pathologic uptake. A spectrum of physiologic distributions, normal variants, and benign mimics of disease have been described in the literature; yet, even when armed with a comprehensive knowledge of these patterns, interpreting radiologists and nuclear physicians may still encounter diagnostic uncertainty. Single-photon emission computed tomography (SPECT) with integrated computed tomography (CT) is a novel technology that, when applied to diagnostic iodine 123 or iodine 131 ((131)I) radioiodine scintigraphy, may accurately localize and help distinguish benign mimics of disease, with the potential to alter the management plan. SPECT/CT is increasingly being used with radioiodine scintigraphy to evaluate patients with thyroid cancer and shows promise for improving imaging specificity and reducing false-positive results.

Nuclear medicine traditionally employs planar and single photon emission computed tomography (SPECT) imaging techniques to depict the biodistribution of radiotracers for the diagnostic investigation of a range of disorders of endocrine gland function. The usefulness of combining functional information with anatomy derived from computed tomography (CT), magnetic resonance imaging (MRI), and high resolution ultrasound (US), has long been appreciated, either using visual side-by-side correlation, or software-based co-registration. The emergence of hybrid SPECT/CT camera technology now allows the simultaneous acquisition of combined multi-modality imaging, with seamless fusion of 3D volume datasets. Thus, it is not surprising that there is growing literature describing the many advantages that contemporary SPECT/CT technology brings to radionuclide investigation of endocrine disorders, showing potential advantages for the pre-operative locating of the parathyroid adenoma using a minimally invasive surgical approach, especially in the presence of ectopic glands and in multiglandular disease. In conclusion, hybrid SPECT/CT imaging has become an essential tool to ensure the most accurate diagnostic in the management of patients with hyperparathyroidism.

Squamous cell carcinoma is the most frequent malignancy of the head and neck region, accounting for 5% of all malignant tumors worldwide. Accurate staging at diagnosis is critical for selection of appropriate treatment strategy. A variety of therapeutic options are used for treatment, including surgery with or without radical dissection, lymph node dissections of various severities, radiotherapy, chemotherapy, and combinations of these. Precise prediction of the extent of primary tumors, detection of unknown primary tumor, cervical lymph node status, and distant metastatic spread is important for treatment planning and prognosis. Accurate evaluation of these factors prior to treatment helps guide surgical extent or radiation porta, minimizing locoregional treatment failure.

The objective of this study was to detect regional patterns of cardiac sympathetic denervation in idiopathic Parkinson disease (IPD) using 11C-hydroxyephedrine (11C-HED) PET and determine the denervation rate over 2 y. Methods: We obtained 62 cardiac 11C-HED PET scans in 39 patients (30 men and 9 women; mean age ± SD, 61.9 ± 5.9 y), including 23 patients with follow-up scans at 2 y. We derived 11C-HED retention indices (RIs; mL of blood/min/mL of tissue) reflecting nerve density and integrity for 480 left ventricular (LV) sectors. We compared IPD patients with 33 healthy controls using z score analysis; RI values ≤ 2.5 SDs were considered abnormal. We expressed global and regional LV denervation as the percentage extent of z score severity and severity-extent product (SEP) on 9-segment bullseye maps and decline in cardiac sympathetic innervation as the 2-y difference in SEP (diff-SEP). Results: Baseline 11C-HED PET in the 39 IPD patients revealed an RI mean of 0.052 ± 0.022 mL of blood/min/mL of tissue. In comparison with data from normal controls, 12 patients had normal 11C-HED PET, 5 showed mild denervation (percentage extent < 30%), and 22 had moderate to severe denervation (percentage extent > 30%, z score ≤ 2.5 SD). In the 23 paired PET scans, worsening cardiac denervation (global diff-SEP > 9) occurred in 14 of 23 (60.9%) patients over 2 y, including percentage LV abnormality (59% increasing to 66%), z-severity (–2.4 down to –2.5), and SEP (–195 to –227) (P = 0.0062). We found a mean annual decline of 4.6% ± 5.6 (maximum, 13%) in 11C-HED retention from a baseline global RI mean of 0.0481 ± 0.0218 to 0.0432 ± 0.0220 (P = 0.0009). At baseline, 5 patients with normal uptake had no interval change; 3 with mild denervation developed interval decline in lateral and inferior segments (diff-SEP –82 to –99) compared with anterior and septal segments (–65 to –79), whereas the reverse pattern occurred in 15 patients with severe baseline denervation. Conclusion: Progressive decline in cardiac sympathetic neural integrity in IPD patients occurs at a modest rate over 2 y on 11C-HED scans with marked heterogeneity and a regional pattern of involvement and decline.

Adrenocortical cancer (ACC) is an uncommon primary neoplasm of the adrenal cortex with dismal prognosis. It often presents with symptoms and signs of adrenal cortical hormone hypersecretion and abdominal mass effect or is incidentally detected as an adrenal mass on imaging performed for other indications. Endocrine evaluation, comprehensive staging, and meticulous resection are crucial to ensure the best possible outcome. Despite extensive initial surgical resection, local and distant metastases are not uncommon with disappointing 5-year survival, although progress is being made at high-volume centers. Accurate restaging of recurrent disease is important to guide further management. Mitotane, external beam radiation and chemotherapy, and newer anticancer systemic treatments are used as adjunctives for inoperable disease and distant metastases. Contrast-enhanced CT and MRI are first-line imaging modalities for evaluation of ACC to characterize adrenal masses and to determine tumor resectability. Emerging literature supports F-FDG PET/CT use to determine the malignant potential of adrenal masses. In patients with a diagnosis of ACC, FDG PET/CT is sensitive for detecting metastatic disease, and its tumor accumulation has been correlated to pathology, Weiss scores, and prognosis. Metomidate, labeled with C for PET or with I for SPECT/CT, allows characterization of an adrenal mass as being of adrenocortical origin with high specificity. Taking advantage of its adrenocortical avidity, metomidate has been labeled with I for radionuclide therapy in a subset of ACC. In this review, we describe how nuclear medicine imaging, and specifically PET, can assist surgical management of ACC.

PURPOSE to determine whether single time-point single-photon emission computed tomography-computed tomography (SPECT/CT) somatostatin receptor imaging can replace traditional dual time-point planar and SPECT somatostatin receptor scintigraphy for evaluation of neuroendocrine tumors. MATERIALS AND METHODS twenty-four patients (9 males, 15 females; mean age: 56 years; range: 14-82 years) underwent [111-In] pentetreotide scintigraphy, with planar whole-body images acquired at 24 and 48 hours after injection and abdominal SPECT/CT at 24 hours postinjection. Two blinded readers independently interpreted each study, using single time-point (24 hours planar and SPECT/CT) and separately using dual time-point (24- and 48-hours planar, and 24-hour SPECT without CT) image information. Consensus interpretations were compared with surgical pathology, or clinical and radiologic follow-up for at least 12 months. RESULTS Interobserver agreement was excellent (κ = 0.86) for single time-point imaging, and good (κ = 0.56) with dual time-point imaging. After consensus review, single time-point imaging identified pathologic lesions in 11 of 12 subjects with diagnosis of NET at follow-up, and in 0 of 12 subjects without NET (sensitivity 92%; specificity 100%). Dual time-point imaging performed similarly, but missed an additional NET case (sensitivity 83%; specificity 100%). After review of SPECT/CT, the readers considered that additional 48 hours imaging was not necessary in the majority of cases, indicating high degree of confidence with the single time-point imaging. CONCLUSION [111-In] pentetreotide SPECT/CT imaging at 24 hours identifies pathologic disease sites and distinguishes physiologic activity equally well compared to traditional strategies using 2 imaging days. Routine use of SPECT/CT will allow single time-point imaging without loss of diagnostic accuracy, enhancing patient convenience, and clinical throughput.

The purpose of this article is to present our initial experience with hypersecretory adrenal syndromes investigated with radioiodinated I-6-B-iodomethyl-19-norcholesterol (NP-59) and SPECT-CT.Illustrative cases are presented of patients being investigated for adrenal hypersecretory syndromes, with or without adrenal nodules, using NP-59 scintigraphy with SPECT-CT imaging, representing a spectrum of diagnoses. Clinical and imaging data are reviewed to evaluate whether additional information derived from near-simultaneous anatomic localization aids study interpretation.The final diagnoses reached are hyperfunctional and nonfunctioning adrenal nodules, physiological bowel activity, and bilateral adrenal hyperplasia. SPECT-CT assisted study interpretation by localizing focal uptake to the adrenal glands, allowing direct assessment of function within adrenal nodules, and distinguishing physiological bowel activity from adrenal uptake. SPECT-CT provided additional information to planar and SPECT imaging, which improved confidence of study interpretation.Utilization of SPECT-CT with NP-59 scintigraphy allows precise localization of the functional activity to anatomic structures improving diagnostic interpretation.

Hepatic arterial infusion chemotherapy (HAIC) is a palliative therapy option for advanced, unresectable liver metastases from colorectal carcinoma. A woman with multiple colorectal liver metastases was treated with HAIC and systemic chemotherapy. Serial 18F-FDG PET/CT imaging showed local therapeutic response of liver metastases to regional delivery of chemotherapy, but concurrent disease progression at extra-hepatic sites suggesting ineffective systemic chemotherapy. Hepatic disease also progressed in the caudate lobe, likely due to variable regional arterial supply. This case is illustrative of the rationale for HAIC in the management of inoperable hepatic metastases and also demonstrates limitations of this approach.

Rationale and Objectives Hybrid single photon-emission computed tomographic (SPECT) and computed tomographic (CT) imaging for the investigation of neuroendocrine tumors allows the fusion of functional and anatomic information in a rapid and efficient method. The aim of this study was to assess the incremental diagnostic value of 111 In pentetreotide SPECT/CT imaging compared with traditional planar and SPECT imaging with respect to lesion localization and characterization and reader confidence. Materials and Methods Forty-nine patients (23 male, 26 female; mean age, 56.9 years; range, 14–88 years) who underwent 111 In pentetreotide planar, SPECT, and SPECT/CT imaging were eligible for this retrospective study, including patients with suspected or confirmed carcinoid tumors ( n = 24), endocrine pancreatic tumors ( n = 18), medullary thyroid cancer ( n = 3), paragangliomas ( n = 2), and multiple endocrine neoplasia type I ( n = 2). Planar and SPECT images were reviewed by two blinded readers, followed by interpretation using additional SPECT/CT images in a subsequent session. A third reader provided consensus in cases with disagreements. Results In 55 of 89 lesions (61.8%), 111 In pentetreotide SPECT/CT imaging improved lesion localization compared to planar and SPECT imaging; in 25 of 89 lesions (28.1%), SPECT/CT imaging changed lesion classification. In 20 of 49 patients (40.8%) for reader 1 and 14 of 49 patients (28.6%) for reader 2, 111 In pentetreotide SPECT/CT imaging provided incremental diagnostic value, which was considered likely to affect patient management in twelve of 20 and seven of 14 patients, respectively. Increased reader confidence was found in 32 of 49 patients (65.3%) for both readers with uniformly high confidence after SPECT/CT interpretation. Conclusions Hybrid 111 In pentetreotide SPECT/CT imaging provides incremental diagnostic value and greater reader confidence over planar and SPECT imaging. This is achieved though superior lesion localization, the identification of physiologic activity, and additional anatomic information derived from the nondiagnostic CT portion of the study.

OBJECTIVE. The objective of our study was to review recurrent laryngeal nerve (RLN) anatomy and describe the typical 18F-FDG (FDG) PET/CT appearance of vocal cord paresis due to oncology-related RLN injury including a spectrum of presentations, causes, and sites of nerve injury.CONCLUSION. Oncology-related RLN palsy may be caused by direct tumor invasion or its therapy. FDG PET/CT findings should be recognized to avoid misdiagnosis. Laryngoscopy confirms the suspected diagnosis and excludes primary vocal cord neoplasm.

Human studies have reported conflicting results on the association of hypoalbuminemia with osteoporosis.The aim of the study is to test the independent association between hypoalbuminemia and osteoporosis.This is a cross-sectional observation.Patients are the outpatient consecutive individuals with available clinical, laboratory, and densitometry data from 2001 to 2013 in our tertiary care academic medical center.Exposure is hypoalbuminemia defined as serum albumin less than 3.5 g/dL.Osteoporosis is defined as bone mineral density of 2.5 SD or less below the mean peak bone mass of young, healthy adults.Overall, 21 121 patients were included. Mean of age was 61 years (SD 14). There were 4244 males (20.1%) and 1614 patients of African-American ethnicity (7.6%). There was a graded decrease in rate of osteoporosis from 28.0% (n = 33) at albumin of 3 g/dL or less to 9.3% (n = 1548) at albumin greater than 4 g/dL (P.001) at the femoral neck and from 20.3% (n = 24) to 6.1% (n = 1011) at the total hip (P.001). In a fully adjusted model, the odds of osteoporosis at albumin of 3 g/dL or less was 3.31-fold (95% confidence interval [CI] 2.08-5.28, P.001) at the femoral neck, 2.98-fold (95% CI 1.76-5.01, P.001) at the total hip, and 2.18-fold (95% CI 1.43-3.31, P.001) at the lumbar spine as compared with albumin greater than 4 mg/dL. A similar independent association was identified with a longer-observed duration of hypoalbuminemia.In a large population, we report an independent association of osteoporosis with lower levels of serum albumin and a longer-observed duration of hypoalbuminemia.

OBJECTIVE. Extraosseous radioactivity outside of the expected biodistribution is often encountered on 99mTc–methylene diphosphate (MDP) bone scintigraphy, and proper interpretation requires an understanding of the mechanisms underlying this uptake and knowledge of the possible causes, depending on the site or structure involved. CONCLUSION. We present examples of extraosseous radiotracer uptake seen on 99mTc-MDP bone scans in which either SPECT with integrated CT or correlative imaging improved the study's interpretation.

Age was a modifier of the independent association between hyponatremia and osteoporosis (OP). Risk of OP was the highest in the youngest age group as compared to older patients. A longer duration of hyponatremia revealed a similar association with OP in all anatomical sites.Epidemiologic studies provide conflicting results on the relationship between hyponatremia and OP. Our aim is to test the modification effect of age on the relationship between hyponatremia and OP at various anatomical sites in a large patient population.This is a cross-sectional observation of consecutive patients with available bone densitometry, demographic, clinical, and laboratory data from 2001 to 2013 at a single center. OP was defined as a bone mineral density of ≤2.5 standard deviations below the mean peak bone mass of young, healthy adults. Hyponatremia was defined as serum sodium ≤135 mmol/L. Multiple logistic regressions were used to calculate adjusted odds ratio (OR).Overall, 24,784 patients were included. There were 4549 males (18.4 %). Hyponatremia was present in 703 patients (2.8 %), femoral neck OP in 2603 (10.5 %), total hip OP in 1885 (7.5 %), and lumbar OP in 4830 (19.5 %). Total hip OP occurred in 17.6 % (n = 124) of patients with hyponatremia as compared to 6.6 % (n = 880) of patients with sodium level of "140-145" mmol/L (P 0.001). After multivariable adjustments, hyponatremia was associated with 2.46-fold higher odds of total hip OP (95 % CI, 1.36 to 4.46) in age55 years, 1.96-fold (1.13 to 3.41) in age 55 to 67 years, and 1.55-fold (1.13 to 2.12) in age67 years (age-sodium category interaction P value = 0.002).Age appeared as a modifier of the independent association between hyponatremia and OP. Risk of OP was the highest in the youngest age group as compared to older patients.

Inguinoscrotal hernias that contain bladder diverticulae are a rare occurrence. We report the case of a 85 yearold man with intense radioactivity overlying the left pubic tubercle on [Tc99m]-methylene-diphosponate (MDP) bone scan. SPECT/CT imaging established the diagnosis of excreted urinary radioactivity within a large herniated bladder diverticulum. SPECT/CT is a useful technique for evaluation of non-osseous uptake on [Tc99m]-MDP bone scintigraphy

Unexpected radioiodine distributions may be encountered on post-therapy I-131 thyroid cancer scans due to a range of benign physiological processes, causing diagnostic dilemma and potentially mimicking metastatic disease. We present two cases of intense focal uptake related to concentration of radioiodine activity on wrist-watches by differing mechanisms, which should be confirmed by clinical history and not be mistaken for metastatic disease.

PET/CT with (18)F-fluorodeoxyglucose (FDG) or using different radiocompounds has proven accuracy for detection of adrenal metastases in patients undergoing cancer staging. It can assist the diagnostic work-up in oncology patients by identifying distant metastases to the adrenal(s) and defining oligometastatic disease that may benefit from targeted intervention. In patients with incidentally discovered adrenal nodules, so-called adrenal "incidentaloma" FDG PET/CT is emerging as a useful test to distinguish benign from malignant etiology. Current published evidence suggests a role for FDG PET/CT in assessing the malignant potential of an adrenal lesion that has been 'indeterminately' categorized with unenhanced CT, adrenal protocol contrast-enhanced CT, or chemical-shift MRI. FDG PET/CT could be used to stratify patients with higher risk of malignancy for surgical intervention, while recommending surveillance for adrenal masses with low malignant potential. There are caveats for interpretation of the metabolic activity of an adrenal nodule on PET/CT that may lead to false-positive and false-negative interpretation. Adrenal lesions represent a wide spectrum of etiologies, and the typical appearances on PET/CT are still being described, therefore our goal was to summarize the current diagnostic strategies for evaluation of adrenal lesions and present metabolic and anatomic appearances of common and uncommon adrenal lesions. In spite of the emerging role of PET/CT to differentiate benign from malignant adrenal mass, especially in difficult cases, it should be emphasized that PET/CT is not needed for most patients and that many diagnostic problems can be resolved by CT and/or MR imaging.

Nuclear medicine imaging of endocrine disorders takes advantage of unique cellular properties of endocrine organs and tissues that can be depicted by targeted radiopharmaceuticals. Detailed functional maps of biodistributions of radiopharmaceutical uptake can be displayed in three-dimensional tomographic formats, using single photon emission computed tomography (CT) that can now be directly combined with simultaneously acquired cross-sectional anatomic maps derived from CT. The integration of function depicted by scintigraphy and anatomy with CT has synergistically improved the efficacy of nuclear medicine imaging across a broad spectrum of clinical applications, which include some of the oldest imaging studies of endocrine dysfunction.

This is an interactive module aimed at senior medical students and radiology residents during a nuclear medicine rotation that discusses the common imaging findings of conditions that cause hyperthyroidism. Typical cases of Graves disease, Plummer disease, toxic multinodular goiter, and thyroiditis are presented in an interactive fashion using illustrative case examples accompanied by multiple-choice questions. Issues that arise following radioiodine therapy with regard to Nuclear Regulatory Commission rules, and causes and mechanisms of iodine-induced hyperthyroidism and hypothyroidism are also discussed. It is anticipated that an individual will go through the presentation in a self-guided manner. It will likely take approximately 1 hour to complete the entire presentation. While this basic presentation should suffice for medical students and junior residents, it is not meant to be a definitive source of facts for more senior radiologists. Those that require more in-depth information can utilize some of the selected resources listed at the end of the presentation or consult a nuclear medicine textbook. Because of the question and answer format, it is hoped that this presentation will be useful for medical students, radiology residents, and even practicing radiologists as a review tool.

Summary Objectives Although widely adopted, the accuracy of post-chemoradiotherapy (CRT) 18 F-fluorodeoxygluocose positron emission tomography/computed tomography (PET/CT) for predicting locoregional failure (LRF) in human papillomavirus-related (HPV+) oropharyngeal cancer (OPC) remains poorly characterized. We assessed the predictive value of 3-month PET/CT response for LRF in this population. Materials and methods 101 consecutive patients with stage III-IV HPV+ OPC who underwent definitive CRT with pre-treatment and 3-month post-CRT PET/CT at our institution from 3/2005-3/2011 were included. 3-month PET/CT response was re-classified as complete-response (CR), near-CR, or incomplete-response ( Results Among 98 patients with an evaluable primary tumor, LF occurred in 2/67 patients with CR, 0/20 with near-CR, and 1/11 with max thresholds or % change did not improve the accuracy of 3-month PET/CT. Use of additional PET/CT surveillance after 3 months in 67 patients accurately detected both LF (96%) and RF (97%). Conclusions In the largest study to-date of PET/CT response assessment in HPV+ OPC, 3-month PET/CT response demonstrated high NPV for LRF, though with disappointing sensitivity and PPV. Subsequent PET/CT surveillance showed potential utility for early detection of LRFs.

Endocrine tumors are hormonally active benign or malignant neoplasms arising within endocrine organs or from specialized cells of the amine precursor uptake and decarboxylation (APUD) system that are increasing in incidence as a result of sensitive biochemical tests and high-resolution diagnostic imaging. Not unlike tumors of other systems, endocrine neoplasms are heterogenous with variable prognosis characterized by well-differentiated thyroid cancer with very favorable outcome, medullary thyroid cancer and neuroendocrine-type tumors with intermediate outcomes, and anaplastic thyroid, adrenocortical, and Merkel cell cancers with the poorest clinical outcomes. Medical imaging has become a key component in diagnosis and staging of endocrine malignancies; however, even with great advances in computed tomography and magnetic resonance imaging, detection of small primary tumors and metastases continues to be a challenge. Complimentary functional imaging targets tumor cellular processes that actively accumulate radiopharmaceuticals, allowing sensitive and highly specific oncological imaging. Surveillance of endocrine malignancies commonly combines functional imaging with tumor-specific laboratory biomarkers. Furthermore, functional imaging studies can predict efficacy of radionuclide or receptor-based therapies. The last decade has seen an increasing use of combined PET-CT and SPECT-CT scanners designed to create functional and anatomic maps with resultant incremental diagnostic capabilities. These technologies together with the development of novel PET and SPECT radiopharmaceuticals make patient-individualized functional imaging protocols possible, based on the histological grade, degree of differentiation, and genetic profile of their endocrine neoplasm.

Thyroid cancer is the most common endocrine malignancy in adults, with 44,670 (10,740M:33,930F) newly diagnosed cases reported in the USA in 2010 and 1,690 deaths. The incidence of thyroid cancer continues to rise, with a 2.4-fold increase in incidence since 1975, based largely upon detection of small (≤2 cm) tumors, which represent 87 % of newly diagnosed cases. After initial diagnosis, staging and risk stratification are used to individualize treatment decisions, inform on prognosis for an individual patient, decide on the use of postoperative 131I therapy, and determine the frequency and intensity of follow-up. A growing number of studies confirm that radioiodine 131I SPECT/CT is a powerful diagnostic tool, overcoming many limitations encountered with planar imaging interpretation. SPECT/CT reduces the number of equivocal radioiodine foci encountered in the neck and body and allows more precise characterization of the etiology (benign vs. malignant) of focal radioiodine uptake, contributing to completion of staging in thyroid cancer by improved characterization of N and M scores. The additional information obtained with SPECT/CT impacts management in a significant number of patients. The new technology of SPECT/CT has changed the field and may lead to reassessment of current management protocols and guidelines in thyroid cancer.

Dynamic bone scanning with (99m)Tc-labeled diphosphonates and (18)F-labeled sodium fluoride provides functional information sensitive for subtle changes in bone turnover and perfusion, which assists the clinical management of numerous osseous pathologies. This article reviews the mechanisms of uptake of (99m)Tc-labeled diphosphonates and (18)F-sodium fluoride and discusses and compares the performance of these bone-seeking radiotracers for clinical and research applications, using dynamic and multiple-time-point imaging protocols and quantitative techniques.

The utility of preablation radioiodine scans for the management of differentiated thyroid cancer remains controversial.To determine the contribution of preablation Iodine 131 (131-I) planar with single-photon emission computed tomography/computed tomography (SPECT/CT; diagnostic [Dx] scans) to differentiated thyroid cancer staging.Prospective sequential series at university clinic.Using American Joint Committee on Cancer (AJCC) tumor, node, metastasis (TNM) staging, seventh edition 320 patients post-total thyroidectomy were initially staged based on clinical and pathology data (pTN) and then restaged after imaging (TNM). The impact of Dx scans with SPECT/CT on N and M scores, and TNM stage, was assessed in younger, age45 years, n = 138 (43%), and older, age ≥ 45 years, n = 182 (57%) patients, with subgroup analysis for T1a and T1b tumors.In younger patients Dx scans detected distant metastases in 5 of 138 patients (4%), and nodal metastases in 61 of 138 patients (44%), including unsuspected nodal metastases in 24 of 63 (38%) patients initially assigned pathologic (p) N0 or pNx. In older patients distant metastases were detected in 18 of 182 patients (10%), and nodal metastases in 51 of 182 patients (28%), including unsuspected nodal metastases in 26 of 108 (24%) patients initially assigned pN0 or pNx. Dx scans detected distant metastases in 2 of 49 (4%) T1a, and 3 of 67 (4.5%) T1b patients.Dx scans detected regional metastases in 35% of patients, and distant metastases in 8% of patients. Information acquired with Dx scans changed staging in 4% of younger, and 25% of older patients. Preablation scans with SPECT/CT contribute to staging of thyroid cancer. Identification of regional and distant metastases prior to radioiodine therapy has significant potential to alter patient management.

To review the benefits of single photon emission computed tomography (SPECT)/computed tomography (CT) hybrid imaging for diagnosis of various endocrine disorders.We performed MEDLINE and PubMed searches using the terms: "SPECT/CT"; "functional anatomic mapping"; "transmission emission tomography"; "parathyroid adenoma"; "thyroid cancer"; "neuroendocrine tumor"; "adrenal"; "pheochromocytoma"; "paraganglioma"; in order to identify relevant articles published in English during the years 2003 to 2015. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts (case reports, reviews, meta-analyses and abstracts) concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology.The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging, with seamless fusion of three-dimensional volume datasets. The usefulness of combining functional information to depict the bio-distribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin, with anatomy derived from CT, has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function. The literature describes benefits of SPECT/CT for (99m)Tc-sestamibi parathyroid scintigraphy and (99m)Tc-pertechnetate thyroid scintigraphy, (123)I- or (131)I-radioiodine for staging of differentiated thyroid carcinoma, (111)In- and (99m)Tc- labeled somatostatin receptor analogues for detection of neuroendocrine tumors, (131)I-norcholesterol (NP-59) scans for assessment of adrenal cortical hyperfunction, and (123)I- or (131)I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma.SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy from CT, translating to improved diagnostic accuracy and meaningful impact on patient care.

To determine whether cardiac sympathetic denervation in idiopathic Parkinson disease (IPD) affects the left ventricle in a distinct regional pattern versus a more global pattern with use of carbon 11 (11C) meta-hydroxyephedrine (HED) positron emission tomography (PET).This prospective study was approved by the institutional review board and was compliant with HIPAA. Informed consent was obtained from all subjects. Cardiac PET was performed with 11C HED in 27 patients with IPD (20 men and seven women aged 50-74 years; mean age, 62 years±6 [standard deviation]). 11C HED retention indexes (RIs), which reflect nerve density and integrity, were determined. RIs for 33 healthy control subjects (15 men and 18 women aged 20-78 years; mean age, 47 years±17) were used as a control database. Patients with IPD were compared with control subjects by using z score analysis. Global and segmental measurements of sympathetic denervation were expressed as percentage extent, z score severity, and severity-extent product (SEP). Group comparisons were performed with the Student t test.The mean 11C HED RI was 0.086 mL of blood per minute per milliliter tissue±0.015 for control subjects and 0.043 mL of blood per minute per milliliter tissue±0.016 for patients with IPD (P0001). When compared with normative data from the control database, profound cardiac denervation (global extent50%) was seen in most patients (19 of 27 patients, 70%). Four patients had normal 11C HED studies and four had mild denervation (global extent25%). The mean global denervation extent was 62%±38, the mean severity z score was -2.7±1.2, and the mean SEP was -202±131 (range, -358 to 0). Segmental analysis revealed relative sparing of anterior and proximal septal segments (mean extent, 48%-51%; mean severity z score, -2.47 to -2.0; mean SEP, -167 to -139), with lateral and proximal inferior segments more severely affected (mean extent, 68%-73%; mean severity z score, -2.8 to -2.62; mean SEP, -271 to -230). Patients with normal findings or preserved denervation did not significantly differ in mean age (t=1.09) or disease duration (t=0.44) compared to patients with severe sympathetic denervation.Cardiac sympathetic denervation in IPD is extensive, with a segmental pattern that involves the proximal lateral left ventricular wall most severely, with relative sparing of the anterior and proximal septal walls.

Purpose The aims of this study were to: (1) estimate the volumetric and metabolic growth rate of non-small cell lung cancer (NSCLC), (2) evaluate disease progression prior to treatment, and (3) explore the effects of tumor growth rate and time to treatment (TTT) on survival outcome. Methods Patients with inoperable stages I–III NSCLC with serial pre-treatment PET/CT scans were eligible for this study. PET-derived metabolic tumor volumes (PET-MTV) and CT-derived gross tumor volumes (CT-GTV) were contoured using PET/CT information. Normalized standardized uptake values (NSUV) in tumors including the NSUVmean and NSUVmax were measured. Tumor growth rates expressed as doubling time (DT) were estimated using an exponential model. Pre-treatment disease progression defined as the development of any new site of disease on PET/CT and change in TNM stage (AJCC 7th ed.) were recorded. Growth rate and tumor progression were analyzed with respect to overall (OS) and progression free survival (PFS). Results Thirty-four patients with a median inter-scan interval (ISI) of 43 days and TTT of 48 days were analyzed. Tumor volumes showed remarkable inter-scan growth while NSUV did not increase significantly. The DT for PET-MTV, CT-GTV, NSUVmean and NSUVmax were 124, 139, 597, and 333 days, respectively. Pre-treatment disease progression occurred in 20.6% patients with longer ISI being a significant risk factor (OR = 1.027, p = 0.02). The optimal threshold ISI to predict progression was 58 days (4.8% vs. 46.2%, p = 0.007). Neither tumor growth rates nor TTT were significantly correlated to OS or PFS. Conclusions NSCLC displays rapid tumor volume growth whereas NSUVmean and NSUVmax are relatively stable over the same time period. Longer delays before initiation of treatment are associated with higher risk of pre-treatment disease progression.

Cardiac uptake of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) is frequently observed on FDG positron-emission tomography combined with computed tomography (PET-CT) performed for diagnosis, staging, and assessment of therapeutic response of lymphoma and solid cancers, despite careful patient preparation to limit myocardial glucose substrate utilisation. We illustrate the varied physiological patterns of cardiac FDG uptake, and show a spectrum of pathological conditions causing FDG uptake within myocardial and pericardial structures, due to clinically important benign and malignant diseases. Recognition and awareness of these various causes of FDG uptake in the heart, along with the appropriate use of correlative contrast-enhanced CT and magnetic resonance imaging (MRI) will facilitate correct interpretation.

A 74-y-old male smoker presented with hemoptysis and was diagnosed with non–small cell lung cancer causing postobstructive pneumonia. He complained of lower back pain. A PET/CT scan was ordered to stage his disease. Sixty minutes after intravenous administration of 595.7 MBq (16.1 mCi) of 18F-FDG

Medullary thyroid cancer (MTC) is a rare, neuroendocrine tumour (NET) of parafollicular C cells comprising 5–8% of all thyroid cancers with variable biological behaviour and prognosis [1]. Overall mean survival in MTC is 75–85% at 10 years [1–3]. Management of both hereditary (20–30%) and sporadic MTC is challenging due to early cervical lymph node metastases occurring in 50% of patients and distant metastases to the liver, lung and bones being found in 10–20% at diagnosis [1, 3]. MTC secretes several neuroendocrine peptides, of which calcitonin (Ct) and less-specific carcinoembryonic antigen (CEA) are useful tumour markers for diagnosis, surveillance and prognosis. Yet despite the high sensitivity of an elevated serum Ct value as a predictor of disease presence, MTC is an elusive and notoriously problematic tumour to image [1, 3]. Anatomy-based imaging with CT and MRI has exhibited limited sensitivity due to the frequent small size of the metastatic deposits. Although a variety of specific and nonspecific scintigraphic techniques such as Tl, Tc-sestamibi, Tc-tetrofosmin, I/I-metaiodobenzylguanidine, Tc-(V)dimercaptosuccinic acid (DMSA), and Inoctreotide have been used to image MTC, none has emerged as the imaging technique of choice [4, 5]. This raises the question as to why we have been unable to successfully image MTC. The rarity of MTC implies that no single centre can collect a sufficient number of cases, and to date there have been no large, cooperative studies to establish optimal imaging protocols. It has become apparent that MTCs are a heterogeneous group of neoplasms, and the biological behaviour of one MTC may differ significantly from that of another. Imaging approaches that have proven successful, for example using F-fluorodeoxyglucose (FDG) PET/CT in lymphoma and solid cancers and In-octreotide for somatostatin receptor scintigraphy (SRS) in carcinoids, may be too simplistic an imaging approach for MTC, which often appears intermediate in biological behaviour between more aggressive neoplasms characterized by high Ki-67 indices, and hormonally active NETs in which FDG PET has limited value. Genetic testing provides a valuable insight into the phenotypic expression of MTC. Genetic mapping has confirmed the central role of germline mutations of the rearranged during transfection (RET) protooncogene in the pathogenesis of inherited MTC and has shown that somatic RET mutations occur in 50–60% of patients with sporadic MTC, and there have been advances in our understanding of how activated RET tyrosine kinase signalling pathways affect tumour growth and angiogenesis [1, 6–8]. Insights from genetic testing allow informed management decisions. As an example, the dilemma of the timing of prophylactic thyroidectomy in multiple endocrine neoplasia type 2 (MEN2), an autosomal D. Rubello (*) :M. C. Marzola : S. Chondrogiannis Department of Nuclear Medicine, Medical Physics, Radiology, Santa Maria della Misericordia Hospital, Via Tre Martiri 140, 45100 Rovigo, Italy e-mail: domenico.rubello@libero.it

Item does not contain fulltext Gender differences in brain dopaminergic activity have been variably reported in the literature. We performed an evaluation for gender effects on striatal dopamine transporter (DAT) binding in a group of normal subjects. Community-dwelling adults (n = 85, 50F/35M, mean age 62.7 +/- 16.2 SD, range 20-85) underwent DAT [(11)C]2-beta-carbomethoxy-3beta-(4-fluorophenyl) tropane (beta-CFT) positron emission tomography (PET) imaging. Gender effects for DAT binding were compared using ANCOVA for two subgroups; young-to-middle aged adults and older adults, using an age threshold of 60 years. There were 54 subjects (24M/30F; mean age 72.9 +/- 7.3) 60 years and older and 31 (11M/20F; mean age 45.0 +/- 11.4) subjects younger than 60. Age-adjusted striatal DAT gender effects were present in the young-to-middle (F = 10.4, P = 0.003) but not in the elderly age group (F = 0.5, ns). Gender differences in nigrostriatal dopaminergic innervation are present, with higher levels of DAT binding in young-to-middle age women compared to men, but not present in the elderly. 01 januari 2012

Medullary thyroid cancer (MTC) arises from parafollicular C cells and is an elusive tumor to image. It occurs as a sporadic neoplasm in 70-80% of cases and is hereditary in 20-30% because of germline mutations of the rearranged during transfection proto-oncogene. Successful disease management relies on accurate staging. Tumor secretory biomarkers are highly sensitive to a disease; however, despite a wide variety of radiopharmaceuticals for molecular imaging that take advantage of hybrid SPECT/CT and PET/CT fusion imaging, imaging of MTC is still problematic. After initial surgical resection, the limited sensitivity of localization of small locoregional disease and the inability to detect early liver metastases hamper the success of later surgical approaches. F-fluorodeoxyglucose PET has been used to detect MTC recurrences with modest success and may be best suited for only a small subset of more biologically aggressive MTCs. Recent developments in PET imaging with novel radiopharmaceuticals targeting specific cellular processes of MTC offer increased sensitivity for identifying recurrence, assessing prognosis, and guiding selection of optimal therapies.

Neuroendocrine tumours (NETs) are rare, heterogeneous, and often hormonally active neoplasms. Nuclear medicine (NM) imaging using single photon- and positron-emitting radiopharmaceuticals allows sensitive and highly specific molecular imaging of NETs, complementary to anatomy-based techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI). Somatostatin-receptor scintigraphy is a whole-body imaging technique widely used for diagnosis, staging and restaging of NETs. The increasing availability of hybrid single-photon emission CT (SPECT)/CT cameras now offers superior accuracy for localization and functional characterization of NETs compared to traditional planar and SPECT imaging. The potential role of positron-emission tomography (PET) tracers in the functional imaging of NETs is also being increasingly recognized. In addition to 2-[ 18 F]-fluoro-2-deoxy-d-glucose (FDG), newer positron-emitting radiopharmaceuticals such as 18 F-dihydroxyphenylalanine (DOPA) and 68 Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) peptides, show promise for the future. This article will summarize the role of current and emerging radiopharmaceuticals in NM imaging of this rare but important group of tumours.

Positron emission tomography (PET) has seen an increasing clinical utilization in the last decade, such that it is now a standard oncology imaging modality. Its success is based on the detection of altered fluorine-18 fluorodeoxyglucose (18F-FDG) biodistribution, reflecting glucose transport/metabolism in malignant tumor tissues. Integrated PET/computed tomography cameras combine functional and anatomical information in a synergistic manner that improves diagnostic interpretation, and newer positron-emitting radiopharmaceuticals have been developed to expand the application of non-FDG PET imaging. The increasing use of cross-sectional imaging procedures has led to a more frequent detection of incidental adrenal masses. Although conventional imaging modalities such as computed tomography and MRI can characterize the majority of these lesions, 18F-FDG PET has been reported as a useful tool to distinguish benign from malignant etiologies in indeterminate adrenal masses. Although 18F-FDG PET has enjoyed success in staging a wide range of cancers, including detection of adrenal metastases and evaluation of adrenocortical carcinoma, it has had limited impact for the evaluation of neuroendocrine tumors. Positron-emitting amine precursor and somatostatin analogs have been validated in research settings to provide accurate imaging of enterochromaffin and chromaffin neuroendocrine tumors and medullary thyroid cancer. The aim of this review article is to provide an overview of the role of 18F-FDG and newer positron-emitting radiopharmaceuticals in the evaluation of adrenal and neuroendocrine tumors.

Somatostatine receptor scintigraphy (SRS) with somatostatine analogs is nowadays established as a first-line tool in the detection, staging and evaluation of the response of neuroendocrine tumors (NETs) and some neural crest tumors, yielding much better results than conventional imaging techniques [1] as many subtypes of these tumors overexpress a high density of somatostatine receptors at the cell surface [2, 3]. This overexpression of the somatostatin receptors, however, may also be present in some other tumors, such as differentiated thyroid carcinoma, lung cancer, breast cancer, meningiomas, well-differentiated astrocytomas, pituitary tumors, lymphoma and several others [4–7]. Some benign conditions, mainly related to the presence of inflammatory cells, i.e., in thyroidal oftalmopathy [8], may also show an increased expression of these surface receptors.

Background and purpose Incidentally discovered adrenal masses are commonly seen with high resolution diagnostic imaging performed for indications other than adrenal disease. Although the majority of these masses are benign and non-secretory, their unexpected discovery prompts further biochemical and often repeated imaging evaluations, sufficient to identify hormonally active adrenal masses and/or primary or metastatic neoplasms to the adrenal(s). In the present paper we investigate the role of PET and PET/CT for the detection of adrenal incidentalomas in comparison with CT and MRI. Materials and methods a systematic revision of the papers published in PubMed/Medline until September 2010 was done. Results The diagnostic imaging approach to incidentally discovered adrenal masses includes computed tomography (CT), magnetic resonance imaging (MRI) and more recently positron emission tomography (PET) with radiopharmaceuticals designed to exploit mechanisms of cellular metabolism, adrenal substrate precursor uptake, or receptor binding. Conclusion The functional maps created by PET imaging agents and the anatomic information provided by near-simultaneously acquired, co-registered CT facilitates localization and diagnosis of adrenal dysfunction, distinguishes unilateral from bilateral disease, and aids in characterizing malignant primary and metastatic adrenal disease.

The purpose of this study was to evaluate the feasibility of staging differentiated thyroid carcinoma (DTC) before initial radioiodine therapy using diagnostic radioiodine-131 ((131)I) scintigraphy with SPECT/CT and to determine the additional value of SPECT/CT.Forty-eight patients (12 men and 36 women; age range, 17-82 years) with DTC underwent diagnostic (131)I planar imaging and SPECT/CT scintigraphy reinterpreted by two readers, one of whom was not blinded to patients' clinical details. Staging and scoring of carcinomas was done by use of TNM with three levels of sequential information: histopathologic analysis and chest radiograph data, planar images, and SPECT/CT data. Restaging based on the imaging findings was designated as "iTNM."Diagnostic (131)I scintigraphy allowed TNM staging of DTC before initial radioiodine therapy. Planar images detected previously unsuspected distant disease in four (50%) of eight patients with a score of M1. SPECT/CT changed the planar scan interpretation for 19 (40%) of 48 patients, detecting regional nodal metastases in four patients and clarifying equivocal focal neck uptake in 15 patients. Compared with histopathologic analysis and chest radiograph data, planar images and SPECT/CT changed the postsurgical DTC stage for 10 (21%) of 48 patients. SPECT/CT information changed the proposed (131)I therapeutic dose for 28 (58%) of 48 patients, on the basis of our department protocol.Diagnostic (131)I scintigraphy, planar images, and SPECT/CT complete the postsurgical staging of DTC. SPECT/CT reduces the number of equivocal diagnoses on planar imaging and improves the interpretation of (131)I scintigraphy. The consequent changes in TNM scores and staging should influence the (131)I dose prescribed at initial therapy.