Biochemically recurrent prostate cancer: rationalisation of the approach to imaging.

AIM: To assess the utility of magnetic resonance imaging (MRI) in addition to the additive benefit of the conventional imaging techniques, computed tomography (CT) and nuclear medicine (NM) bone scintigraphy, for investigation of biochemical recurrence (BCR) post-prostatectomy where access to prostate specific membrane antigen (PSMA) positron-emission tomography (PET)-CT is challenging. MATERIALS AND METHODS: Relevant imaging over a 5-year period was reviewed. Ethical approval was granted by the internal review board. All patients with suspected BCR, defined as a PSA ≥0.2 ng/ml on two separate occasions, underwent a retrospective imaging review. This was performed on PACS archive search database in a single centre using search terms "PSA" and "prostatectomy" in the three imaging methods; MRI, CT, and NM bone scintigraphy. All PSMA PET CT performed were recorded. RESULTS: One hundred and eighty-five patients were identified. Patients with an MRI pelvis that demonstrated distant metastases (i.e., pelvic bone metastases or lymph node involvement more cranial to the bifurcation of the common iliac arteries) were more likely to have a positive CT and/or NM bone scintigraphy. The Pearson correlation coefficient between the findings of M1 disease at MRI pelvis and the presence of distant metastases at CT thorax, abdomen, pelvis and NM bone scintigraphy was calculated at 0.81 (p<0.01) and 0.91 (p<0.01) respectively. CONCLUSION: An imaging strategy based on risk stratification and technique-specific selection criteria leads to more appropriate use of resources, and in turn, increases the yield of conventional imaging methods. MRI prostate findings can be used to predict the additive value of CT/NM bone scintigraphy allowing a more streamlined approach to their use.

Diagnostic Imaging: Appropriate and Safe Use.

The use of diagnostic radiography has doubled in the past two decades. Image Gently (children) and Image Wisely (adults) are multidisciplinary initiatives that seek to reduce radiation exposure by eliminating unnecessary procedures and offering best practices. Patients with an estimated glomerular filtration rate less than 30 mL per minute per 1.73 m2 may have increased risk of nephropathy when exposed to iodinated contrast media and increased risk of nephrogenic systemic fibrosis when exposed to gadolinium-based contrast agents. American College of Radiology Appropriateness Criteria can help guide specific diagnostic imaging choices. Noncontrast head computed tomography is the first-line modality when a stroke is suspected. Magnetic resonance imaging stroke protocols and computed tomography perfusion scans can augment evaluation and potentially expand pharmacologic and endovascular therapy timeframes. Imaging should be avoided in patients with uncomplicated headache syndromes unless the history or physical examination reveals red flag features. Cardiac computed tomography angiography, stress echocardiography, and myocardial perfusion scintigraphy (nuclear stress test) are appropriate for patients with chest pain and low to intermediate cardiovascular risk and have comparable sensitivity and specificity. Computed tomography pulmonary angiography is the preferred test for high-risk patients or those with a positive d-dimer test result, and ventilation-perfusion scintigraphy is reserved for patients with an estimated glomerular filtration rate less than 30 mL per minute per 1.73 m2 or a known contrast allergy. Computed tomography with intravenous contrast is preferred for evaluating adults with suspected appendicitis; however, ultrasonography should precede computed tomography in children, and definitive treatment should be initiated if positive. Ultrasonography is the first-line modality for assessing right upper quadrant pain suggestive of biliary disease. Mass size and patient age dictate surveillance recommendations for adnexal masses. Imaging should not be performed for acute (less than six weeks) low back pain unless red flag features are found on patient history. Ultrasonography should be used for the evaluation of suspicious thyroid nodules identified incidentally on computed tomography.

Assessment of an in-house phantom for the quality control of a clinical gamma camera.

OBJECTIVE: Since in-house phantoms may provide effective quality control for gamma cameras in clinical settings, this study aims to assess an in-house phantom designed to perform quality control tests of a gamma camera using locally available, affordable materials. This is of particular importance in developing countries where scientific support may not be readily available. MATERIALS AND METHODS: The phantom was made from cylindrical plexiglass with a diameter of 230 mm and thickness of 60 mm. The phantom design was based on NEMA recommendations and only used materials that are locally available and generally accessible to most nuclear medicine departments and require minimal engineering instruction. RESULTS: The phantom demonstrated high levels of reliability and accuracy. The integral uniformity range was between 1.93% and 2.40%. The differential uniformity ranged between 1.48% and 1.70%. CONCLUSION: This work demonstrates that in-house phantoms are capable of monitoring gamma camera performance. This approach is particularly useful when scientific support is not easily accessible and when commercial phantoms are not readily available.

Recommendations for nuclear neuroimaging of patients with neurological disorders in the COVID-19 era.

The novel coronavirus disease 2019 (COVID-19) pandemic has changed people's normal lives in a very short time causing extensive infections and mortality, which required the national health systems to be adapted to new situation. Changes in healthcare services included modifications of standard procedures in nuclear medicine departments in order to limit COVID-19 spreading and protect patients and personnel. Here, we recommend management of patients with neurological diseases and especially dementia and movement disorders, who are referred for neuroimaging with nuclear medicine techniques.

Challenges and priorities in skeletal, gastrointestinal, hepatobiliary, genitourinary and lung scintigraphy during the COVID-19 pandemic.

On December 29, 2019, a hospital in the City of Wuhan, Hubei Province, in Central China, admitted four individuals with pneumonia. The hospital reported this occurrence to the local center for disease control (CDC), which lead Wuhan CDC staff to initiate a field investigation with a retrospective search for pneumonia patients. On December 31, 2019, the World Health Organization (WHO) was alerted by the Chinese authorities for several cases of pneumonia of unknown origin in the City of Wuhan. On January 7, 2020, a novel virus was identified as the causative agent, belonging to the Coronaviridae family (Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2). Within the same month, the virus spread to other provinces of China, as well as a number of neighbouring countries. On February 11, 2020, the WHO announced that the SARS-CoV-2 - caused infection would be called coronavirus disease 2019 (COVID-19). On February 15, 2020, the first death due to COVID-19 in Europe was reported; a Chinese tourist who died in France. The first COVID-19 case was diagnosed in Greece on February 26th. The WHO declared COVID-19 a pandemic on 11 March 2020. On March 12th, movie theaters, gyms and courtrooms were closed in Greece and on March 13th, with 190 confirmed cases and 1 death, malls, cafés, restaurants, bars, beauty parlors, museums and archaeological sites were also closed. So far, COVID-19 pandemic has affected the way people live and work globally, and has resulted in extreme strain on the healthcare systems worldwide. Most of the nuclear medicine studies are performed on an out-patient basis. Therefore, without effective implementation of the required preventive measures, there is a significant risk for viral transmission when visiting nuclear medicine departments, particularly in periods of high community spread.

EANM practice guideline/SNMMI procedure standard for RAIU and thyroid scintigraphy.

INTRODUCTION: Scintigraphic evaluation of the thyroid gland enables determination of the iodine-123 iodide or the 99mTc-pertechnetate uptake and distribution and remains the most accurate method for the diagnosis and quantification of thyroid autonomy and the detection of ectopic thyroid tissue. In addition, thyroid scintigraphy and radioiodine uptake test are useful to discriminate hyperthyroidism from destructive thyrotoxicosis and iodine-induced hyperthyroidism, respectively. METHODS: Several radiopharmaceuticals are available to help in differentiating benign from malignant cytologically indeterminate thyroid nodules and for supporting clinical decision-making. This joint practice guideline/procedure standard from the European Association of Nuclear Medicine (EANM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) provides recommendations based on the available evidence in the literature. CONCLUSION: The purpose of this practice guideline/procedure standard is to assist imaging specialists and clinicians in recommending, performing, and interpreting the results of thyroid scintigraphy (including positron emission tomography) with various radiopharmaceuticals and radioiodine uptake test in patients with different thyroid diseases.

The use of labelled leucocyte scintigraphy to evaluate chronic periprosthetic joint infections: a retrospective multicentre study on 168 patients.

Labelled leucocyte scintigraphy (LS) is regarded as helpful when exploring bone and joint infections. The aim of this study was to evaluate the utility of LS for the diagnosis of chronic periprosthetic joint infections (PJIs) in patients exhibiting arthroplastic loosening. One hundred sixty-eight patients were referred to centres for treatment of complex PJI. One hundred fifty underwent LS using 99mTc-HMPAO (LLS); 18 also underwent anti-granulocyte scintigraphy (AGS) and 13 additional SPECT with tomodensitometry imaging (SPECT-CT). The LS results were compared with bone scan data. For all, the final diagnoses were determined microbiologically; perioperative samples were cultured. LS values were examined, as well as sensitivity by microorganism, anatomical sites, and injected activity. LS results were also evaluated according to the current use of antibiotics or not. The sensitivity, specificity, and positive predictive value of LLS were 72%, 60%, and 80%, respectively. LLS performed better than did AGS. SPECT-CT revealed the accurate locations of infections. The sensitivity of LS was not significantly affected by the causative pathogen or the injected activity. No correlation was evident between the current antibiotic treatment and the LS value. The test was more sensitive for knee (84%) than hip arthroplasty (57%) but was less specific for knee (52% vs. 75%). Sensitivity and specificity of LLS varied by the location of infection bone scan provide no additional value in PJI diagnosis. Current antibiotic treatment seems to have no influence on LS sensitivity as well as labelling leukocyte activity or pathogens responsible for chronic PJI.

Interobserver agreement on interpretation of conventional dacryocystography and dacryoscintigraphy findings: A retrospective single-centre study.

IMPORTANCE: This study assesses the interobserver agreement on dacryocystography (DCG) and dacryoscintigraphy (DSG) findings. BACKGROUND: There are no standard grading criteria to guide the interpretation of conventional DCG and DSG findings and therefore there may be a degree of subjectivity. This study evaluates the level of interobserver agreement in the interpretation of DCG and DSG findings. DESIGN: A retrospective observational study at the Royal Adelaide Hospital. PARTICIPANTS: A total of 165 patients who presented with epiphora with 276 DCGs and 290 DSGs performed were included in this study. METHODS: DCG and DSG images were obtained, anonymized, randomized and interpreted by three independent oculoplastic surgeons. Standard grading criteria were set for both DCG and DSG images. Data from all observers were analysed for interobserver agreement using Kappa (κ) statistics, generated using a variation of Cohen's kappa for multiple observers. MAIN OUTCOME MEASURES: Level of interobserver agreement (κ values) in the grading of DCG and DSG findings. RESULTS: There was an overall moderate interobserver agreement for DCG findings (κ = 0.55), with the highest agreement on interpreting canalicular obstruction (κ = 0.80), followed by proximal nasolacrimal duct obstruction (κ = 0.67) and normal patency (κ = 0.63). There was an overall fair interobserver agreement for DSG findings (κ = 0.36), with the best being moderate agreement (κ = 0.42-0.50) for interpreting pre-sac delay and post-sac proximal delay. CONCLUSIONS AND RELEVANCE: DCG offers good reliability in interpreting patent and obstructed systems. On the other hand, DSG has poor agreement and highlights some of the limitations in the ability to guide epiphora management.

Somatostatin receptor expression in non-classical locations - clinical relevance?

In-111 pentetreotide (Octreoscan) is a radiolabeled somatostatin analog with high binding affinity to somatostatin receptors (SSTR) used in somatostatin receptor scintigraphy (SRS). Pentetreotide labelled with In-111 is widely used due to its high affinity to SSTR 2 and 5. SSTR are expressed on neuroendocrine cells as well as several non-neural and non-endocrine cells with varying levels of density. We retrospectively reviewed articles and publications related to octreoscan accumulation in sites that classically do not have high concentrations of SSTR as well as in organs and tissues from diseases which are not usually diagnosed by octreoscan. The significance of a positive uptake as assessed by octreoscan in non-somatostatin receptor related diseases is not fully understood yet. Localization of octreotide in non-oncological disease states such as inflammation is due to presence of SSTR in activated immunological cells, over-expression by activated cells in the respective tissue and SSTR expression by blood vessels. In granulomatous diseases, over-expression of SSTR2 preferential binding sites were detected in epitheloid and giant cells. The purpose of the current study is to identify octreoscan localization in non-somatostatin receptor related disease sites to better understand the mechanism of this nonspecific accumulation which may help expand the clinical utilization of functional imaging utilizing somatostatin receptor scintigraphy in diagnosis and perhaps therapy.

Italian consensus on diagnosis and treatment of differentiated thyroid cancer: joint statements of six Italian societies.

BACKGROUND: Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. METHODS: Six scientific Italian societies entitled to cure thyroid cancer patients (the Italian Thyroid Association, the Medical Endocrinology Association, the Italian Society of Endocrinology, the Italian Association of Nuclear Medicine and Molecular Imaging, the Italian Society of Unified Endocrine Surgery and the Italian Society of Anatomic Pathology and Diagnostic Cytology) felt the need to develop a consensus report based on significant scientific advances occurred in the field. OBJECTIVE: The document includes recommendations regarding initial evaluation of thyroid nodules, clinical and ultrasound criteria for fine-needle aspiration biopsy, initial management of thyroid cancer including staging and risk assessment, surgical management, radioiodine remnant ablation, and levothyroxine therapy, short-term and long-term follow-up strategies, and management of recurrent and metastatic disease. The objective of this consensus is to inform clinicians, patients, researchers, and health policy makers about the best strategies (and their limitations) relating to the diagnosis and treatment of differentiated thyroid cancer.

The value of local normal limits in quantitative Thallium-201 CZT MPI SPECT.

BACKGROUND: Considering the distinctive characteristics of CZT detectors, automatic quantification of ischemia using normal limits included with software package may deliver suboptimal results for CAD detection. The present study aims to evaluate the benefits of creating normal limits specific to a local population and laboratory protocol. METHODS AND RESULTS: Two groups were selected from patients who had undergone a CZT MPI. Normal limits were generated with the QPS application based on the population with low likelihood of CAD. Using the vendor-supplied and the population-specific normal limits i-TPD and vessel-specific SDS results obtained for patients who had subsequently undergone coronary angiography were compared with coronary angiography data. A weak correlation was observed for low i-TPD (stress TPD minus rest TPD) and SDS values. Both databases gave similar values for the area under the ROC curve concerning i-TPD (0.75 to 0.74) and SDS results (0.72 to 0.75 for the LAD, 0.62 to 0.64 for the LCx, and 0.63 to 0.67 for the RCA). Sensitivity (60%), specificity (78%), and predictive positive (84%) and negative (52%) values were also similar with a diagnostic and prognostic threshold value. CONCLUSION: The use of a population-specific created database did not influence the diagnostic value of thallium-201 MPI QPS results using a CZT camera.

Imaging for the exclusion of pulmonary embolism in pregnancy.

BACKGROUND: Pulmonary embolism is a leading cause of pregnancy-related death. An accurate diagnosis in pregnant patients is crucial to prevent untreated pulmonary embolism as well as unnecessary anticoagulant treatment and future preventive measures. Applied imaging techniques might perform differently in these younger patients with less comorbidity and altered physiology, who largely have been excluded from diagnostic studies. OBJECTIVES: To determine the diagnostic accuracy of computed tomography pulmonary angiography (CTPA), lung scintigraphy and magnetic resonance angiography (MRA) for the diagnosis of pulmonary embolism during pregnancy. SEARCH METHODS: We searched MEDLINE and Embase until July 2015. We used included studies as seeds in citations searches and in 'find similar' functions and searched reference lists. We approached experts in the field to help us identify non-indexed studies. SELECTION CRITERIA: We included consecutive series of pregnant patients suspected of pulmonary embolism who had undergone one of the index tests (computed tomography (CT) pulmonary angiography, lung scintigraphy or MRA) and clinical follow-up or pulmonary angiography as a reference test. DATA COLLECTION AND ANALYSIS: Two review authors performed data extraction and quality assessment. We contacted investigators of potentially eligible studies to obtain missing information. In the primary analysis, we regarded inconclusive index test results as a negative reference test, and treatment for pulmonary embolism after an inconclusive index test as a positive reference test. MAIN RESULTS: We included 11 studies (four CTPA, five lung scintigraphy, two both) with a total of 695 CTPA and 665 lung scintigraphy results. Lung scintigraphy was applied by different techniques. No MRA studies matched our inclusion criteria.Overall, risk of bias and concerns regarding applicability were high in all studies as judged in light of the review research question, as was heterogeneity in study methods. We did not undertake meta-analysis. All studies used clinical follow-up as a reference standard, none in a manner that enabled reliable identification of false positives. Sensitivity and negative predictive value were therefore the only valid test accuracy measures.The median negative predictive value for CTPA was 100% (range 96% to 100%). Median sensitivity was 83% (range 0% to 100%).The median negative predictive value for lung scintigraphy was 100% (range 99% to 100%). Median sensitivity was 100% (range 0% to 100%).The median frequency of inconclusive results was 5.9% (range 0.9% to 36%) for CTPA and 4.0% (range 0% to 23%) for lung scintigraphy. The overall median prevalence of pulmonary embolism was 3.3% (range 0.0% to 8.7%). AUTHORS' CONCLUSIONS: Both CTPA and lung scintigraphy seem appropriate for exclusion of pulmonary embolism during pregnancy. However, the quality of the evidence mandates cautious adoption of this conclusion. Important limitations included poor reference standards, necessary assumptions in the analysis regarding inconclusive test results and the inherent inability of included studies to identify false positives. It is unclear which test has the highest accuracy. There is a need for direct comparisons between diagnostic methods, including MR, in prospective randomized diagnostic studies.

The bone scintigraphy in the diagnosis and management in children with febrile osteoarticular pain.

BACKGROUND: Bone and joint infections are common diseases in pediatrics. They still are a public health problem in Tunisia. The diagnosis is based on clinical, biological, radiological and skeletal scintigraphy arguments. The purpose of this study is to determine the contribution of triple phase bone scan in the exploration of musculoskeletal pain febrile child. METHODS: This was a descriptive and retrospective study. It was conducted over a period of 5 years. It has interested all children explored in nuclear medicine department with suspected acute osteomyelitis (OMA) , osteoarthritis (OA) or septic arthritis (SA) referred from Orthopaedic Infantile service. All these patients had, alongside the conventional radiologic exams, a triple phase bone scan HMDP-Tc99m. RESULTS: We collected 62 patients. Among the selected diagnoses, there were: 22 OMA, 4 OA, 4 SA. The mean age of the patients was 5.58 years with a male predominance. The main reason for consultation was pain. Fever was ≥ 38° C in 80 % of cases. The preferential localization was the lower limb (93.5 %). The quantitative and qualitative bone scan abnormalities objectified led to a correct diagnosis of: 18 OMA, 3 OA and 2 SA with a respectively estimated sensitivity and specificity of 76.6% and 90.6% in the all population. CONCLUSIONS: Bone scan demonstrates early abnormalities allowing osteoaricular infection diagnosis. It highlights the infection site, and draws a map of the lesions. Currently, imaging modalities differ in their availability, their cost, their input and diagnostic accuracy but they are complementary.

The EANM practice guidelines for bone scintigraphy.

PURPOSE: The radionuclide bone scan is the cornerstone of skeletal nuclear medicine imaging. Bone scintigraphy is a highly sensitive diagnostic nuclear medicine imaging technique that uses a radiotracer to evaluate the distribution of active bone formation in the skeleton related to malignant and benign disease, as well as physiological processes. METHODS: The European Association of Nuclear Medicine (EANM) has written and approved these guidelines to promote the use of nuclear medicine procedures of high quality. CONCLUSION: The present guidelines offer assistance to nuclear medicine practitioners in optimizing the diagnostic procedure and interpreting bone scintigraphy. These guidelines describe the protocols that are currently accepted and used routinely, but do not include all existing procedures. They should therefore not be taken as exclusive of other nuclear medicine modalities that can be used to obtain comparable results. It is important to remember that the resources and facilities available for patient care may vary.

Adopting new gamma cameras and reconstruction algorithms: Do we need to re-establish normal reference values?

BACKGROUND: The impact of adopting new single photon emission computed tomography (SPECT) cameras and new reconstruction algorithms on left ventricular (LV) volumes has not been well established. We sought to understand the impact of hardware and software changes on normal LV reference ranges. METHODS: Consecutive patients who underwent stress Tc-99m tetrofosmin 8-frame gated SPECT MPI were screened. Patients with a history of myocardial infarction, coronary revascularization, abnormal MPI, or known LV dysfunction/reduced ejection fraction were excluded. A total of 1953 consecutive normal patients, with rest LV end-diastolic volume (EDV) and end-systolic volume (ESV) measurements were analyzed. After stratifying according to sex, LV volumes indexed to body surface area were compared across the different gamma cameras. RESULTS: In a normal population, measurements with CZT were different from those obtained by the dual-headed NaI gamma cameras for LV EDVi (men: 53.6 ± 10.4 vs 48.3 ± 10.2 mL/m(2) and women: 43.3 ± 8.9 vs 37.8 ± 9.3 mL/m(2); P < 0.001) and LV ESVi (men: 21.7 ± 7.0 vs 16.9 ± 6.2 mL/m(2) and women: 13.4 ± 5.3 vs 10.6 ± 4.7 mL/m(2); P < 0.001). Inter- and intra-observer reliability for all measures was excellent. These findings were verified in a prospectively collected cohort. A sub-analysis of LV measurements comparing new resolution recovery and standard reconstruction software revealed no significant differences in LV measures. CONCLUSION: This study demonstrates that normal references ranges of LV volumes vary between SPECT cameras and confirms the need for establishing reference values that are camera specific.

Validation of the paracetamol absorption test for measuring gastric tube emptying in esophagectomized patients versus gold standard scintigraphy.

OBJECTIVE: Scintigraphy is the gold standard for objective measurement of delayed gastric tube emptying after esophagectomy. The aim of this pilot study is to validate, by reference to scintigraphy, the paracetamol absorption test for measuring gastric tube emptying in esophagectomized patients. MATERIAL AND METHODS: The paracetamol absorption test and scintigraphy were performed simultaneously in 13 patients who had undergone an esophagectomy with gastric tube reconstruction. Emptying was calculated for both methods and compared. Post-esophagectomy symptoms and quality of life (QoL) were assessed by European Organization on Research and Treatment of Cancer questionnaires. RESULTS: Mean time to 50% emptying was 17 min measured with the paracetamol absorption test and 23 min with scintigraphy. For time to 25% emptying, Bland-Altman calculation gave a bias of 1.6 min and 95% limits of agreement (LoA) of -6.3 to 9.5 min. For time to 50% emptying, there was one outlier resulting in a bias of -6.33 min and 95% LoA of -36.4 to 23.8 min. For time to 75% emptying, bias was -11.6 min and 95% LoA of -38.5 to 15.4 min. Post-esophagectomy symptoms were similar to those reported previously, and QoL was comparable to the general Swedish population. CONCLUSIONS: There was reasonably close correlation between the paracetamol absorption test and scintigraphy for time to 25% and 50% emptying, except for one outlier. For time to 75% emptying the methods were in less accordance. The results indicate that the paracetamol absorption test may be a useful screening tool for identifying delayed gastric tube emptying in this patient group.