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Introduction Surgical treatment of hyperparathyroidism related to chronic kidney disease is a real challenge for Brazilian public health care. High cost medications and long waiting lines to perform preoperative exams, especially technetium Tc 99m Sestamibi (MIBI) are some of the reasons. Despite the reality that the aid of localization exams are questionable in this scenario, doctors are too apprehensive in performing surgery without it. Objective The study aimed at evaluating the efficacy of surgery for renal hyperparathyroidism without preoperative MIBI. Methods A total of 114 patients were surgically treated. Total parathyroidectomy with autotransplantation and subtotal parathyroidectomy were carried out without preoperative MIBI. Results and conclusion Among the 114 patients undergoing surgery, 37 had secondary hyperparathyroidism in dialysis replacement, and 77 patients had post-renal transplant persistent disease. We were successful in 107 cases with only 7 failures (93.8% of success rate). Among these failures, only one parathyroid gland was not found in 4 cases, 2 parathyroid glands were not found in 2 cases and in 1 patient the 4 glands were found but this patient remained hypercalcemic and a postoperative diagnosis of supernumerary parathyroid gland was made. Surgery for treatment of renal hyperparathyroidism proved to be an effective (93.8%) and reproductible procedure, even without MIBI.

Objective Primary hyperparathyroidism (PHPT) is one of the most frequent endocrine diseases. Most of the patients with PHPT are asymptomatic, and only 20% of them become symptomatic with increasing levels of calcium. It has been reported that normocalcemic primary hyperparathyroidism (NPHPT) may be the incipient period of PHPT where calcium (Ca) levels are in normal range, and it may advance to overt PHPT. Early diagnosis of PHPT is important in order to prevent its complications. In this retrospective study, we aimed to evaluate the role of 99mTc-MIBI parathyroid scintigraphy on lesion detection in patients with NPHPT. Material and methods The parathyroid scintigraphy database was reviewed retrospectively in patients with PHPT. 117 patients who underwent 99mTc-MIBI scintigraphy were recruited to the study. Serum calcium level above 10.5 mg/dl was considered as hypercalcemia. Results A total of 117 patients (female/male:98/19) mean serum PTH levels (mean ± SD) were 149 ± 97 pg/ml in normocalcemic group (Ca:9.6 ± 0.6 mg/dl, n:38) and 189 ± 135 pg/ml in hypercalcemic group (Ca:11.4 ± 0.6 mg/dl, n:79) (p:0.072). The sex and ages were not different between the scintigraphy positive and negative groups, but the lesion detection rates with parathyroid scintigraphy were 42% in normocalcemic group and 81% in hypercalcemic group (p Conclusions Several factors including serum Ca, the imaging protocol, existence of multiglandular disease, the size and MIBI biokinetics of the adenoma may influence lesion detectability in parathyroid scintigraphy. Although high serum Ca level is an important parameter in predicting its success, parathyroid scintigraphy remains a valuable diagnostic method even in patients with NPHPT.

The objective of this study was to investigate the clinical manifestations and pathologic appearances of the submandibular gland (SMG) in Stevens-Johnson syndrome (SJS).Patients with autologous transplantation of SMG for treatment of severe dry eye between March 1998 and May 2018 were divided into the SJS group (70 cases) and non-SJS group (50 cases) according to the history of SJS. The SMG weight and computed tomography volume and salivary flow rate were measured. The concentration index and secretion index were estimated using scintigraphy with technetium-99m-pertechnetate. Histopathology studies of SMG tissues were conducted, and the acini parameters were measured using a digital image analyzer.A decreased computed tomography volume and weight was observed in 48.57% the SJS group and 2% in the non-SJS group (P.01). The rest whole, acid-stimulated whole, and SMG rest salivary flow rates decreased in the SJS group (P.05). The normal SMG concentration index (37.5% vs 96.67%, P.001) and secretion index (35% vs 96.67%, P.001) rates were lower in the SJS group than in the non-SJS group. The glandular parenchyma was reduced, the acinar space was widened, and the fat content was increased in the SJS group.SMG atrophic and degenerative changes occurred in the SJS group, with a decrease in salivary secretion function in more than half of the patients.

PURPOSE We aimed to compare the inter-center cranial computed tomography (CT) acquisition rates, CT findings, CT-related radiation dose, and variability of CT acquisition parameters for neurologic events among patients with implantable cardioverter-defibrillator (ICD) or left ventricular assist device (LVAD). METHODS A total of 224 patients (ICD group, n=155; LVAD group, n=69) who had at least one cranial CT scan were enrolled from 3 medical centers (Centers A, B, and C). The variability and effect of the number, indication, and findings of cranial CT scans as well as CT acquisition parameters including tube potential (kV), tube current (mAs), tube rotation time, slice collimation, and spiral or sequential scanning techniques on CT dose index volume (CTDIvol), and total dose length product (DLP) were analyzed. RESULTS The mean DLP value of Center A and the mean CTDIvol values of Centers A and C were significantly lower than those of Center B (P

Systemic sclerosis (SSc)-associated gastrointestinal (GI) complications are attributed to a variety of factors, including diet, microbiota dysbiosis, or GI transit abnormalities. Our objective was to examine the contribution of abnormal GI transit to SSc Medsger GI severity scores and/or University of California Los Angeles Scleroderma Clinical Trial Consortium Gastrointestinal Tract (UCLA GIT) 2.0 symptoms.Patients with SSc and GI symptoms (n = 71) and healthy controls (n = 18) underwent whole gut transit (WGT) scintigraphy to assess transit from the esophagus to the colon. The presence of delayed transit and percent emptying in each GI region were measured. We compared the WGT measurements between categories of the Medsger GI severity score (0-4) and across UCLA GIT 2.0 domains and total score (0-3).A total of 88% of patients had1 abnormal region of the gut on WGT scintigraphy. All patients requiring total parenteral nutrition had delayed small bowel transit, compared to only approximately 11% of patients in other Medsger GI severity groups (P ≤ 0.01). Severe colonic transit delays were more likely in patients with Medsger GI scores of 3 (pseudo-obstruction and/or malabsorption) compared to other Medsger GI groups (P = 0.02). Seventy-percent of these patients had ≤30% colonic emptying at 72 hours. Modest associations were noted between gastroesophageal reflux disease symptoms and delayed esophageal (r = -0.31, P = 0.05) and gastric emptying (r = -0.32, P = 0.05).These data are important in providing evidence that SSc bowel disease affects transit of GI content and that delay in transit accounts in part for both bowel symptoms and Medsger GI severity. Prospective studies examining the benefit of early therapeutic intervention targeting GI transit abnormalities in patients at high risk for severe GI complications are needed.

Discutem-se os mecanismos que presidem a obtenção de imagens por métodos não invasivos (medicina nuclear, ultrassonografia, tomografia computorizada de transmissão e de emissão). Introduzem-se definições para sensibilidade, especificidade, valor de previsão e precisão. Defendem-se estratégias de diagnóstico clínico para lesões ocupantes de espaço e sugerem-se orientações para futuro desenvolvimento.

One of the major effects of the COVID-19 pandemic within nuclear medicine was to halt performance of lung ventilation studies, due to concern regarding spread of contaminated secretions into the ambient air. A number of variant protocols for performing lung scintigraphy emerged in the medical literature which minimized or eliminated the ventilation component, due to the persistent need to provide this critical diagnostic service without compromising the safety of staff and patients. We have summarized and reviewed these protocols, many of which are based on concepts developed earlier in the history of lung scintigraphy. It is possible that some of these interim remedies may gain traction and earn a more permanent place in the ongoing practice of nuclear medicine.

Introduction Gland-preserving surgery is often used for benign tumours in the parotid gland. Partial superficial parotidectomy via a periauricular incision may bring satisfactory cosmetic outcomes but the disease control outcome remains unrevealed. This study evaluated functional and disease control outcomes after gland-preserving surgery via periauricular incision for pleomorphic adenoma of the parotid gland. Methods This longitudinal study included 248 consecutive patients with parotid pleomorphic adenoma who underwent the preservation of most normal parotid tissues and the facial nerve combined with the en-bloc resection of tumours via periauricular incision. Postoperative complications, subjective satisfaction, salivary function, and tumour recurrence were assessed in each patient. The secretory function of the salivary gland was measured using salivary scintigraphy at 6 months after surgery, and ultrasonography was regularly followed. Results Median tumour size was 2.5 cm (range, 0.8–5.2 cm) and median operation time was 55 min (range, 39–88 min). All tumours were safely removed by gland-preserving surgery via periauricular incision without extension to Blair or hairline incision and tumour spillage. Temporary and permanent paralysis of the facial nerve was 14 (5.6%) and none of the study patients, respectively. Postoperative complications were minor and Frey's syndrome was found in 6 (2.4%) patients. The Secretary function of the affected gland was equal to that of the unaffected gland. No patients had a recurrence for a median follow-up of 78 months (range, 24–126 months). Conclusions Functional gland-preserving surgery via periauricular incision can treat pleomorphic adenoma in the parotid gland with satisfactory functional, cosmetic, and disease control outcomes.

Tuberculosis (TB) continues to be a major cause of death worldwide that can be effectively treated with timely diagnosis and treatment. With the advent of nuclear imaging techniques like 18Fluorine Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography (18F-FDG) PET/CT, the diagnosis of tuberculosis, particularly its extrapulmonary forms, has received great impetus in cases where microbiological confirmation cannot be achieved. Although detection of mycobacteria either by staining, culture or nucleic acid amplification techniques still form the gold standard of diagnosis, newer diagnostic techniques are always welcome in the field which can expedite clinical management. Use of radiolabeled antibiotics is one such evolving sphere which needs further research. Moving ahead from radiolabeled leukocytes, antibiotics are being increasingly focused upon to act as a vehicle to locate infectious lesions. Antibiotics like ciprofloxacin have been labeled with diagnostic radionuclides such as Technetium-99m (Tc-99m) and used to image many infectious diseases with encouraging results in TB. However, the nonspecific attributes of ciprofloxacin have hindered its growth to assist the diagnosis of TB. A novel approach would be to utilize ethambutol, a specific antitubercular agent, which has been found to be safe and effective in the diagnosis of TB in the available published studies. Ethambutol is known to be taken up specifically by tubercular lesions. This forms the basis of using Tc-99m labelled ethambutol for imaging TB lesions. An added advantage would be its ability to differentiate tubercular from malignant and fungal lung lesions that are the usual differentials in patients suspected of having TB. Most of the studies involving ethambutol have been done in skeletal TB and its validation in other forms of TB is still awaited. Recently the role of PET-CT has also been explored in human studies using 11C Rifampicin to study the antibiotic uptake in tubercular lesions. This review summarizes the available evidence regarding diagnosis of TB by radiolabeled antibiotic imaging to emphasize the need for accelerated research in the fight against TB.

The field of nuclear medicine and molecular imaging has grown tremendously over the past several years with the approval of new imaging agents, diagnostic radiopharmaceuticals, and radiopharmaceutical therapies. Clinical research continues to expand within nuclear medicine and molecular imaging departments. Working as a nuclear medicine technologist on a clinical trial or with investigational radiopharmaceuticals can be quite different from working in an approved-drug setting in the clinic. Nuclear medicine technologists involved in clinical trials can be at the front line of following rigorous trial requirements and ensuring good-quality data. The details of working in clinical research are often not taught in nuclear medicine technologist programs. As such, there is an emerging need for education about clinical research for both experienced and new nuclear medicine technologists, particularly for those working with investigational radiopharmaceuticals. This article is an introduction to the SNMMI Clinical Trials Network Research Series for Technologists. This series of articles aims to provide education on working in the context of a clinical trial within the nuclear medicine department. The following 7 topics will be addressed in the series: ethical issues in clinical research, application of good clinical practice to clinical research in medical imaging, contract research organizations with application in clinical imaging, a clinical research primer on the regulatory process for how and when radiopharmaceuticals can be used and the role of the institutional review board, use of imaging agents in therapeutic drug development and approval, imaging agent trials, and imaging agents with radiopharmaceutical therapies in clinical trials. Other topics may be added over the course of the development of the series.

We aimed to find and compare the efficacy of ultrasonography (US), technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy (MIBI-S), and single-photon emission computed tomography-computed tomography (SPECT-CT) in detecting the localization of parathyroid adenomas in patients with primary hyperparathyroidism.In total, 348 patients were included in this study. Preoperative parathyroid imaging with US, MIBI-S, and SPECT-CT was evaluated and compared with operative findings. The results of the imaging methods were compared with pathology and operation reports.In 318 patients (91.3%), one of the imaging methods was able to localize the lesion correctly. US detected the localization of the parathyroid lesions correctly in 268 patients (77%), whereas SPECT-CT and MIBI-S were correct in 254 (73%) and 209 (60%) patients, respectively. There was a statistically significant relationship between the parathyroid hormone (PTH) level and 3 imaging methods' success rates (P.05). The PTH cut-off value, which best determined the correct localization, was 152.5 pg/mL for US, 143 pg/mL for MIBI-S, and 143 pg/mL for SPECT-CT. It was observed that the correct localization rate for parathyroid lesions increased with higher PTH levels.In our study population, US was more successful, in most cases, than other imaging methods in localizing parathyroid lesions but SPECT-CT was more accurate in localizing mediastinal lesions. In addition, it was found that preoperative PTH levels affect the accuracy of imaging methods.

BACKGROUND The clinical utility of fatty meal stimulated cholescintigraphy particularly using a standardized formulation in patients with suspected functional gallbladder disorder has not been extensively studied. We present our seven-year clinical experience using an Ensure plus protocol. METHODS A retrospective study was performed on patients undergoing stimulated cholescintigraphy using Ensure Plus for evaluation of suspected functional gallbladder disorder. A gallbladder ejection fraction (GBEF) of

AIM Rectal neuroendocrine tumours (NETs) are the most common type of gastrointestinal NET. European Neuroendocrine Tumour Society guidelines suggest that rectal NETs measuring ≤10 mm are indolent with low risk of spread. In practice, many patients with lesions ≤1 cm do not undergo complete tumour staging. However, the size of the lesion may not be the only risk factor for nodal involvement/metastases. The aim of this study was to determine if MRI ± nuclear medicine imaging alters tumour stage in patients with rectal NETs ≤10 mm. METHODS Patients referred to a tertiary NET centre between 2005 and 2020 who met the inclusion criteria of a rectal NET ≤10 mm, full cross-sectional imaging, primarily an MRI scan and, if abnormal findings were identified, a subsequent 68 Ga-DOTATATE positron emission tomography scan were included. All patients were followed up at our institution. RESULTS In all, 32 patients with rectal NETs 10 mm or less were included in the study: 16 women; median age 58 years (range 33-71); 47% (n = 15) were referred from bowel cancer screening procedures. The median size of the lesions was 5 mm (range 2-10 mm). 81% (n = 26) were World Health Organization Grade 1 tumours with Ki67

OBJECTIVE To determine the prevalence of intra-patient inter-metastatic heterogeneity based on positron emission tomography (PET)/computed tomography (CT) in patients with metastatic castration-resistant prostate cancer (mCRPC) and to determine the prevalence of neuroendocrine disease in these patients and their eligibility for radioligand therapies (RLTs). PATIENTS AND METHODS This multicentre observational prospective clinical study will include 100 patients with mCRPC from five Canadian academic centres. Patients with radiological or biochemical progression and harbouring at least three metastases by conventional imaging will be accrued. Intra-patient inter-metastatic heterogeneity will be determined with triple-tracer imaging using fluorine-18 fluorodeoxyglucose (18 F-FDG), gallium-68-(68 Ga)-prostate-specific membrane antigen (PSMA)-617 and 68 Ga-DOTATATE, which are a glucose analogue, a PSMA receptor ligand and a somatostatin receptor ligand, respectively. The 68 Ga-PSMA-617 and 18 F-FDG PET/CT scans will be performed first. If at least one PSMA-negative/FDG-positive lesion is observed, an additional PET/CT scan with 68 Ga-DOTATATE will be performed. The tracer uptake of individual lesions will be assessed for each PET tracer and patients with lesions presenting discordant uptake profiles will be considered as having inter-metastatic heterogeneous disease and may be offered a biopsy. EXPECTED RESULTS The proposed triple-tracer approach will allow whole-body mCRPC characterisation, investigating the inter-metastatic heterogeneity in order to better understand the phenotypic plasticity of prostate cancer, including the neuroendocrine transdifferentiation that occurs during mCRPC progression. Based on 68 Ga-PSMA-617 or 68 Ga-DOTATATE PET positivity, the potential eligibility of patients for PSMA and DOTATATE-based RLT will be assessed. Non-invasive whole-body determination of mCRPC heterogeneity and transdifferentiation is highly innovative and might establish the basis for new therapeutic strategies. Comparison of molecular imaging findings with biopsies will also link metastasis biology to radiomic features. CONCLUSION This study will add novel, biologically relevant dimensions to molecular imaging: the non-invasive detection of inter-metastatic heterogeneity and transdifferentiation to neuroendocrine prostate cancer by using a multi-tracer PET/CT strategy to further personalise the care of patients with mCRPC.

We aimed to compare the reliability of bone scintigraphy (BS) and fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)—derived parameters in the detection of active arthritis in 28-joint areas and evaluate the reliability of joint counts between BS and clinical assessment in patients with rheumatoid arthritis (RA). We enrolled 106 patients (67 in the development group and 39 in the validation groups) with active RA who underwent BS, 18F-FDG PET/computed tomography (CT), and clinical evaluation of disease activity. We compared the results of BS-derived joint assessment with those of PET-derived and clinical joint assessments. Subsequently we developed a disease activity score (DAS) using BS-positive joints and validated it in an independent group. The number of BS-positive joints in 28-joint areas significantly correlated with the swollen /tender joint counts (SJC/TJC) and PET-derived joint counts. A BS uptake score of 2 (strong positive) was significantly more sensitive compared with a BS uptake score of 1 (weak positive) in detecting a PET-positive joint among the 28-joints. After conducting multivariate analyses including erythrocyte sediment rate (ESR) and patient global assessment (PGA) in addition to BS-derived parameters, BS/DAS was obtained as follows: 0.056 × number of BS-positive joints in 28 joints + 0.012 × ESR + 0.030 × PGA. A significant correlation between BS/DAS and DAS28-ESR was confirmed in the validation group. Strong positive uptake of BS is sensitive and reproducible for the detection of active joints, and can complement the clinical assessment of disease activity in RA.

Purpose In this study, we aim to evaluate the efficacy and safety of 225AC-DOTATATE targeted alpha therapy in advanced-stage paragangliomas (PGLs). Methods Nine (6 males and 3 females) consecutive patients with histologically proven PGLs were treated with 225Ac-DOTATATE targeted alpha therapy (TAT) and concomitant radiosensitizer, capecitabine, at 8-weekly intervals up to a cumulative activity of ~ 74 MBq. The primary endpoint included evaluating therapy response and disease control rate (DCR) using the RECIST 1.1 criteria. Additional secondary endpoints comprised clinical response assessment using EORTC QLQ-H&N35 questionnaire, Karnofsky Performance Scale (KPS), Eastern Cooperative Oncology Group performance status (ECOG), analgesic score (AS), dose alterations of anti-hypertensive drugs (anti-HTN), and the safety and side-effect profile evaluation as per CTCAE criteria version 5.0. Results Following 225Ac-DOTATATE treatment, morphological response revealed partial response in 50%, stable disease in 37.5%, and disease progression in 12.5%, with a DCR of 87.5%. Similarly, the symptomatic response was remarkable, and anti-HTN drugs were stopped in 25% and reduced in 37.5%. Another significant finding in our study revealed a morphologic DCR of 66.6% (2/3) in patients who failed previous lutetium-177 peptide receptor radionuclide therapy (177Lu-PRRT). Regarding the KPS, ECOG, and AS performance scores, a notable improvement was observed post-225Ac-DOTATATE treatment. The QLQ-H&N35 symptom scores evaluated in seven H&N PGL patients showed significant improvement in all aspects. No improvement in sexual function was noted (P = 0.3559). Despite the significant reduction in the analgesic score post-treatment (P = 0.0031), the QLQ-H&N35 revealed only marginal significance concerning the intake of pain killers (P = 0.1723). No grade III/IV hematological, renal, and hepatological toxicities were noted. Conclusion The evidence from this study suggests 225Ac-DOTATATE therapy is effective and safe in the treatment of advanced-stage PGLs and also reports a clear benefit even in patient’s refractory to the previous 177Lu-PRRT. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-021-05632-5.

Background The purpose of this study was to investigate the efficiency of quantitative parameters of bone scintigraphy in detecting clinically active joint and high disease activity in patients with rheumatoid arthritis. Methods We retrospectively enrolled 65 patients with rheumatoid arthritis who underwent bone scintigraphy for diagnostic work-up. Quantitative analysis of bone scintigraphy images was conducted using an in-house software, and joint uptake ratio of 28 joints was measured for the calculation of the disease activity score of 28 joints using erythrocyte sedimentation rate (DAS28-ESR). The relationship between joint uptake ratio and clinical findings and the efficiency of joint uptake ratio in detecting clinically active joint and high disease activity were assessed. Results Clinically active joint (tender and/or swollen joints) showed significantly higher joint uptake ratio than did other non-affected joints (p p Conclusion Quantitative parameters of bone scintigraphy showed high sensitivity and NPV for detecting clinically active joint and high disease activity in patients with rheumatoid arthritis.

Introduction This study aimed to evaluate the effect of sono-scintigraphic correlation on the success of minimal invasive parathyroidectomy (MIP) via surgeon performed continuous intraoperative sonographic guidance in patients operated for primary hyperparathyroidism(PHPT) without intact parathormone (PTH) measurement. Materials and methods A retrospective analysis of a prospective database was conducted to review patients who underwent MIP (July 2017-October 2019). The screened parameters were preoperative PTH level, preoperative ultrasonography (US), preoperative scintigraphy, intraoperative US, intraoperative frozen section analysis, postoperative PTH level and permanent pathology report. Intraoperative intact PTH measurement was not employed due to institutional policy. Results Preoperative US alone localized the specific side (right/left, inferior/superior) of abnormality in 54 out of 74 (72.97%) cases. Scintigraphy alone localized the specific side in 58 (78.37%) cases. The sensitivity of preoperative US and scintigraphy alone was 76.05% and 86.56%, respectively. Sono-scintigraphic discordance was present in 6 cases (8.1%) and intraoperative real-time US predicted accurate localization of adenoma in 4 (66.6%) and scintigraphy in 2 (44.4%) patients. The frozen section analysis confirmed parathyroid cells in all cases evaluated. Conclusion Sono-scintigraphic concordance with intraoperative real-time imaging increases surgical success rates in cases where MIP is planned under the circumstances of limited resources regarding unavailability of intact PTH measurement.

Peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues such as 177-lutetium DOTATATE is an effective treatment modality for neuroendocrine tumours, paragangliomas, and neuroblastomas. However, renal and haematopoietic toxicities are the major limitations of this therapeutic approach. The renal toxicity of PRRT is mediated by renal proximal tubular reabsorption and interstitial retention of the radiolabelled peptides resulting in excessive renal irradiation that can be dose-limiting. To protect the kidneys from PRRT-induced radiation nephropathy, basic amino acids are infused during PRRT as they competitively bind to the proximal tubular cells and prevent uptake of the radionuclide. In adults, 1 L of a basic amino acid solution consisting of arginine and lysine is infused over 4 h commencing 30 min prior to PRRT. However, this volume of amino acids infused over 4 h is excessive in small children and can result in hemodynamic overload. This is all the more relevant in paediatric oncology, as many of the children may have been heavily pretreated and so may have treatment-related renal and or cardiac impairment. We have therefore developed the following guidelines for safe paediatric dosing of renal protective amino acid infusions during PRRT. Our recommendations have been made taking into consideration the renal physiology in small children and the principles of safe fluid management in children.

To determine in a group of patients with progressive metastatic neuroendocrine tumors (PM-NETs) treated with 177Lu-DOTATATE whether a correlation exists between somatostatin receptor (SSTR)-2 expression in various tumors on baseline 68Ga-DOTATATE PET and their response to therapy. A secondary aim was to determine whether an association exists between tumor product of diameter (POD) and PET-derived Krenning score.Patients treated PM-NETs who had SSTR-2 overexpression (SSTR-RADS 5) on screening 68Ga-DOTATATE PET and CT at baseline and 3 months after therapy completion were included. Marker lesions on baseline CT were reassessed on CT after therapy using adapted Southwest Oncology Group solid tumor evaluation criteria. For each lesion, bidimensional diameter on CT and SSTR expression on PET (SSTR-RADS uptake scorePET-derived Krenning score) were recorded. Logistic regression models fitted through generalized estimating equations were used to assess for an association between SSTR expression and response to therapy, or lesion's POD.Forty-one patients with SSTR-RADS 5 PM-NETs treated with 177Lu-DOTATATE were included. There were 135 marker lesions (mean 3.2 lesions/patient) with Krenning score of 4 (n = 74), 3 (n = 44) or 2 (n = 17). There was no association found between SSTR-2 expression, as determined by SSTR-RADS uptake score or PET-derived Krenning score, and POD or response to therapy.In patients with SSTR-RADS 5 PM-NETs treated with 177Lu-DOTATATE, there was similar response to therapy for all lesions with PET-generated Krenning score ≥2. No correlation was found between lesion's POD and level of tracer uptake.

The landscape of nuclear oncology is rapidly changing. The advent of molecular radionuclide theranostics, multidisciplinary tumor board decision making, artificial intelligence and radiomics interpretation of diagnostic imaging, evolution of pharmacogenomics prediction of tumor response, and regulatory requirements for prospective individual dosimetry are just some of the elements which are broadening the essence of physician responsibility. The burgeoning knowledge base essential for mastering the emergent technologies, and their profound effect on moral philosophic aspects of provision of cancer care, are challenging. The new relationship of the theranostic nuclear physician with respect to shared care of the individual patient, particularly with regard to transparency, accountability, and responsibility for targeted radionuclide diagnosis and therapy of cancer, will be explored in this update.

Dedicated multi-slice single-photon emission computed tomography/computed tomography (SPECT/CT) cameras have become widely available and are becoming a mainstay of clinical practice. The integration of SPECT and CT allow for precise anatomic location of scintigraphic findings. Fusion imaging with SPECT/CT can improve both sensitivity and specificity by reducing equivocal interpretation in comparison to planar scintigraphy or SPECT alone. This review article addresses the technique, basic science principles, and applications of integrated SPECT/CT in the evaluation of musculoskeletal pathology.

The study of the processes and mechanisms of the medium group mass nuclear systems formation (formed in reactions with protons) has both an important fundamental and practical significance. These tasks are especially important for the production of medical radionuclides, which are used for the effective early diagnosis and treatment of the various cancers. Combining the methods of radionuclide imaging with the methods of radionuclide therapy (therapy plus diagnostics—theranostics), it is possible to implement unique methods of non-surgical treatment of tumors with their precise visualization and minimal side effects. Therefore, in this work the experimental and theoretical studies of the nuclear reaction excitation functions with targets: 117Sn and 119Sn in the proton energy range of 6–18 MeV are carried out. Cross sections of the formation of antimony radionuclides are obtained for these reactions, and the mechanisms of such reactions are analyzed. Antimony radionuclides are promising for use in theranostics.

BACKGROUND Appropriate use criteria (AUC) enhance application of cardiovascular imaging techniques but have been applied in limited settings, primarily in common cardiovascular disease processes. There are several complex systemic diseases with cardiovascular implications and special populations with unique cardiovascular considerations that could benefit from appropriateness analysis. Moreover, the high medical complexity of these topics indicate they would benefit from high-yield expert consensus recommendations of the available imaging options. The ASNC Imaging Indications (ASNC-I2) Series will provide a concise overview of relevant disease processes and their multimodality evaluation and will provide consensus clinical indications, diagnostic criteria, and clinical algorithms with representative clinical cases. METHODS For each ASNC-I2 document, a diverse writing group and rating panel will be composed of experts from societies pertinent to the topic, including relevant imaging societies and clinical societies that manage the disease under evaluation. The rating panel will follow robust modified Delphi methodology and commonly-accepted appropriateness methods to create consensus diagnostic criteria, clinical algorithms, and clinical indications that they will then rate with level of agreement recorded. The clinical and imaging experts will provide concise, high-yield clinical summaries of the disease process, the non-imaging evaluation, and multimodality imaging. Relevant cases will be provided highlighting application of the diagnostic criteria and clinical algorithms. CONCLUSION The ASNC Imaging Indications (ASNC-I2) Series will complement the diverse portfolio of documents from ASNC. It will use a multisocietal approach with robust appropriateness methodology to guide use of radionuclide imaging in the multimodality imaging context for the cardiovascular care of patients.

У статті розглядаються можливості динамічних і статичних радіонуклідних досліджень у діагностиці аномалій та оцінці особливостей функціонального стану аномальних нирок. Подано переваги, недоліки та можливості радіонуклідної діагностики при аномаліях кількості, розмірів, положення, відношення та структури нирок. Зроблено висновки про високу діагностичну значимість радіонуклідних досліджень і проведення їх разом з ультразвуковим скринінгом при веденні пацієнтів із поданими аномаліями нирок.

Acute and chronic forms of pyelonephritis are the most common diseases of the urinary system in all age groups. The incidence rate of acute pyelonephritis in children is 19.1 per 1000, chronic pyelonephritis — 5–12.5 per 1000 people. In this paper, based on retrospective analysis, the diagnostic role of radionuclide imaging methods in acute and chronic pyelonephritis has been studied. Due to high sensitivity, radionuclide methods of research allow determining the degree of functional and topographical changes in each kidney in patients with pyelonephritis — secretory function and the nature of passage of the radiopharmaceutical through the renal collecting system and ureter. Radionuclide research methods are sensitive and accurate methods of radiation imaging in pyelonephritis, as well as reliable means for dynamic monitoring in the postoperative observation of patients. The use of radionuclide imaging techniques allows you to establish the cause and effects of pyelonephritis and to develop a rational treatment plan.

Background According to current guidelines, bone scintigraphy is not routinely indicated in patients with invasive bladder cancer prior to radical cystectomy unless specific symptoms are present. These guidelines, however, are based on sparse data of low quality. Objective To assess the clinical impact of routine staging bone scintigraphy on further patient management. Design, setting, and participants A retrospective, single-center study of 1287 consecutive patients, who were scheduled to undergo radical cystectomy due to invasive bladder cancer between January 2000 and December 2017, was conducted. All patients were prospectively followed up according to our institutional protocol. Intervention Bone scintigraphy as staging imaging prior to radical cystectomy. Outcome measurements and statistical analysis The primary endpoint was the change in intended patient management. Secondary endpoints were the need for additional imaging, the diagnostic performance of baseline bone scintigraphy, and the association between clinical and radiological findings on bone metastases and survival. Logistic and Cox regression models were used for univariate and multivariate analyses. Results and limitations Of 1287 patients scheduled for radical cystectomy, 1148 (89%) underwent bone scintigraphy as staging imaging. Overall, baseline bone scintigraphy led to a change in the intended management in 19/1148 (1.7%) patients. Additional imaging was performed in 44/1148 (4%) patients. Although positive bone scintigraphy findings were associated with the occurrence/development of bone metastases, the diagnostic performance of baseline bone scintigraphy was generally poor (positive predictive value, negative predictive value, sensitivity, and specificity were 56%, 89%, 27%, and 96%, respectively). Higher clinical tumor stage and the nonperformance of cystectomy had negative impacts on cancer-specific survival and overall survival, while positive bone scintigraphy was associated with worse cancer-specific survival. This study was limited by its retrospective nature and the lack of follow-up bone scintigraphy in all patients. Conclusions These results demonstrate the limited value of bone scintigraphy in the staging of invasive bladder cancer and do not support its routine use. Patient summary In this study, we looked at the clinical impact of bone scintigraphy on the diagnostics of patients with invasive bladder cancer. We found that routine staging bone scintigraphy had limited impact on further patient management. We conclude that bone scintigraphy should not be part of routine staging in patients with invasive bladder cancer.

Hip prosthetic loosening is often difficult to detect at an early stage, and there has been uncertainty for a long time as to when the loosening occurs and thus to the basic causes. By comparing different diagnostic methods, we found that loosening is best defined as prosthetic migration and measured by radiostereometric analysis. Convincing evidence indicates that poor interlock, poor bone quality, and resorption of a necrotic bone bed may initiate loosening during or shortly after surgery; this forms the basis of the theory of early loosening. Biomechanical factors do affect the subsequent progression of loosening, which may increase subclinically during a long period of time. Eventually, the loosening may be detected on standard radiographs and may be interpreted as late loosening but should to be interpreted as late detection of loosening. The theory of early loosening explains the rapid early migration, the development of periprosthetic osteolysis and granulomas, the causality between wear and loosening, and largely the epidemiology of clinical failure of hip prostheses. Aspects discussed are definition of loosening, the pattern of early migration, the choice of migration threshold, the current understanding of loosening, a less exothermic bone cement, cemented taper-slip stems, a new exciting computed tomography-based technique for simpler implant migration studies, and research suggestions.

Magnetic resonance imaging (MRI) is considered the gold standard for the evaluation of anal fistulas. There is sufficient literature available outlining the interpretation of fistula MRI before performing surgery. However, the interpretation of MRI becomes quite challenging in the postoperative period after the surgery of fistula has been undertaken. Incidentally, there are scarce data and no set guidelines regarding analysis of fistula MRI in the postoperative period. In this article, we discuss the challenges faced while interpreting the postoperative MRI, the timing of the postoperative MRI, the utility of MRI in the postoperative period for the management of anal fistulas, the importance of the active involvement and experience of the treating clinician in interpreting MRI scans, and the latest advancements in the field.

Purpose: To investigate if i) the risk of ischemia on Myocardial Perfusion Scan (MPS) ii) number of coronary angiographies (CAG) performed iii) necessity for invasive (stent implantation or coronary artery by-pass grefting (CABG)) or medical treatment increased in patients infected with COVID-19.Methods:Patients who were referred to MPS between August 2020-April 2021 with a history of active symptomatic Covid-19 infection (confirmed by PCR positivity) in the last 6 months were involved in the study group. Age-and gender matched control group was composed of randomly chosen patients who attended for MPS between January 2019 – September 2019, before pandemic. Frequency of ischemia, CAG, invasive or medical treatments were compared between groups. Results:Ischemia was reported more frequently in the study group (pConclusion:There exists a significant increase in the frequency of ischemia on MPS, undergoing CAG, stent implantation or CABG and initiation of medical therapy in patients with a history of Covid-19 infection in the last 6 months. MPS is a reliable method in patients who present with cardiovascular symptoms in the late COVID period.

Major cerebral vessels have been proposed as a target of defective mitochondrial metabolism in patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes syndrome (MELAS). Cerebral angiographic techniques are not routinely performed in MELAS patients. A systematic literature review was performed to identify studies describing major vessel caliber alterations in MELAS. Twenty-three studies reporting on 46 MELAS patients were included. Alterations in major caliber vessels were present in 59% (27/46) of patients. Dilation occurred in 37% (17/46) of patients, and in 88% (15/17) of them during a stroke-like episode (SLE). Stenosis was reported in 24% (11/46) of patients: 36% (4/11) related to an SLE and 64% (7/11) to dissections or degenerative changes. During an SLE, identification of intracranial vessels dilation or stenosis could be a selection tool for new treatment protocols. Outside SLE, identification of major cerebral vessels dissections and degenerative changes may help to prevent subsequent complications. (c) 2021 Elsevier Masson SAS. All rights reserved.

Thyroglossal duct cysts, which are the most frequently encountered congenital cervical anomalies in children, occur due to embryologic remnants of the thyroglossal duct. Although diagnosis may be challenging, clinicians can be aided by imaging and fine-needle aspiration biopsies. We describe the clinical management of a two-year-old boy with a thyroglossal duct cyst mimicking a goitre on a pertechnetate thyroid scan.

Scanning ion conductance microscopy (SICM) is a type of in situ measurement technology for noncontact detection of samples in electrolytes with nanoscale resolution and has been used increasingly in biomedical and electrochemical fields in recent years. However, there is an inherent contradiction in the technique that makes SICM's sensitivity and accuracy difficult to balance. Higher sensitivity allows for faster probe speeds and higher scanning reliability but leads to lower accuracy, and vice versa. To resolve this problem, an adaptive sensitivity scanning method is proposed here that is designed to increase SICM's imaging efficiency without reducing its scanning reliability and accuracy. In the proposed scanning method, the sensitivity is automatically switched via the bias voltage based on the probe-sample distance. When the probe is located far away from the sample, the probe then predetects the sample position rapidly with high sensitivity. When the sample has been sensed in the high-sensitivity phase, the probe then detects the sample with low sensitivity. The basic theory and the feasibility of the alterable sensitivity detection strategy is also studied using the finite element method (FEM) and by performing experiments in this work. Finally, through testing of the standard silicon and polydimethylsiloxane (PDMS) samples, the proposed method is shown to increase SICM imaging efficiency significantly by up to 5 times relative to the conventional hopping mode without sacrificing the scanning accuracy and reliability.

PURPOSE: The ability of ultrasound to assess pathology is increasing with the development of quantitative parameters. Among these are a set of parameters derived from the recent H-scan analysis of subresolvable scattering. The emergence of these quantitative measures of tissue/ultrasound interactions now enables a study of the unique trajectories of multiparametric features in multidimensional space, representing the progression of specific diseases over time. We develop the mathematical and visual tools that are effective for classifying, quantifying, and visualizing the steady progression of several diseases from independent studies, all within a uniform framework. METHODS: After applying the H-scan analysis of ultrasound echoes, we trained a support vector machine (SVM) to classify the unique trajectories of progressive liver disease from fibrosis, steatosis, and pancreatic ductal adenocarcinoma (PDAC) metastasis. Our approaches include the development of trajectory maps and disease-specific color imaging stains. RESULTS: The multidimensional SVM image classification reached 100% accuracy across the three different studies. CONCLUSION: H-scan trajectories can be useful to track the progression of multiple classes of diseases, improving diagnosis, staging, and assessing the response to therapy.

Introduction The utility of evaluating a sagittal view of CT of the spine is well-known. In many clinical cases, the sagittal view includes noise generated from surrounding objects and may degrade the image quality. Iterative reconstruction (IR) techniques are useful for noise reduction; however, they can reduce spatial resolution. The aim of this study was to evaluate the effectiveness of the adaptive statistical iterative reconstruction (ASiR) for generating sagittal CT images of the spine when compared to filtered back projection (FBP). Methods The image quality of clinical images from 25 patients were subjectively assessed. Three radiologists rated spatial resolution, image noise, and overall image quality using a five-point scale. For objective assessment, z-direction modulation transfer function (z-MTF) was measured using a custom-made phantom. Additionally, z-axis noise power spectrum (z-NPS) was measured using a water phantom. An improved adaptive statistical iterative reconstruction algorithm called ASiR-V was used in this study. Blending levels were 50%, and 100% (ASiR-V50, ASiR-V100, respectively). Results For subjective assessments, images using ASiR-V100 were determined to have the best overall image quality, despite having received the worst score in the assessment of spatial resolution. For objective assessments, the image using ASiR-V50 and ASiR-V100 curves were slightly degraded in terms of low contrast z-MTF when compared to FBP. Conclusion ASiR-V was effective to improve the image quality when compared with FBP when reviewing sagittal reformats of the spine. Implications for practice This study suggests that high resolution is not the only thing that is key when reviewing sagittal CT spinal reformats. Such images should be provided as part of routine CT spine protocols, where available.

Drug delivery to the colon offers great promise for local treatment of colonic diseases as it allows bypassing systemic absorption in the small intestine, thereby increasing luminal drug concentrations in the colon. The primary objective of this in vivo pharmaco-scintigraphy study was to assess the colon drug targeting accuracy of a metronidazole benzoate colonic drug delivery system intended for local treatment of Clostridioides difficile infections. Additionally, it was assessed if the concept of mucoadhesion would increase colonic residence time and promote higher drug bioavailability. Two different capsule formulations were designed and tested in healthy human subjects. Capsules contained either non-mucoadhesive (NM) or mucoadhesive (M) microgranules, both loaded with 100 mg metronidazole benzoate (antibiotic prodrug) and 5 mg samarium oxide (scintigraphy tracer). Filled capsules were coated with a colonic-targeting technology consisting of two functional layers, which allow for accelerated drug release mediated by the intestinal pH in combination with or without colonic bacteria. Coated capsules were neutron-activated to yield the radioisotope 153Sm prior to administration to 18 healthy subjects. Gamma-scintigraphy imaging was combined with the measurement of drug plasma levels. Formulation NM showed high colon-targeting accuracy. Initial capsule disintegration within the targeted ileocolonic region was observed in 8 out of 9 subjects (89%) with colonic arrival times in the range of 3.5 to 12 h and reduced systemic exposure. In contrast, the mucoadhesive formulation M showed some inconsistency regarding the site of initial capsule disintegration (targeting accuracy 56%). Variability of drug release was attributed to self-adhesion and agglomeration of the mucoadhesive microparticles within the capsule. Accurate ileocolonic delivery of metronidazole-loaded microgranules was achieved following oral administration of colonic-targeted capsules. Delayed drug release from NM microparticles in the colon leads to a reduced systemic exposure compared to immediate-release data from literature and presumably elevated drug concentrations in the colonic lumen. This approach offers promising options for the local treatment of colonic diseases.

Introduction This study examined whether time-activity curves (TAC) can be used to differentiate between patients with and without Sjogren's syndrome using SPECT/CT. Methods Thirteen xerostomia patients (5 with Sjogren's syndrome and 8 without Sjogren's syndrome) underwent SPECT/CT. Salivary gland secretion data were digitally observed, producing separate time-activity curves (TAC) for the submandibular glands and parotid glands using SPECT/CT. The salivary gland secretion fraction was defined as A (before stimulation test [counts/frame]) divided by B (after stimulation test [counts/frame]). The A/B ratios of patients with Sjogren's syndrome and those without Sjogren's syndrome were compared using the Mann-Whitney U test for nonparametric data. Results The A/B ratio of parotid glands with Sjogren's syndrome (1.3 ± 0.2) was significantly lower than for those without Sjogren's syndrome (2.7 ± 0.7). The A/B ratio of submandibular glands with Sjogren's syndrome (1.3 ± 0.4) is significantly lower than for those without Sjogren's syndrome (1.8 ± 0.6). Conclusion The TAC for the submandibular glands and parotid glands using SPECT/CT may be useful for the objective and quantitative diagnosis of Sjogren's syndrome.

Objective Coronavirus disease 2019 (COVID‐19) has caused hundreds of thousands of infections and deaths. Efficient diagnostic methods could help curb its global spread. The purpose of this study was to develop and evaluate a method for accurately diagnosing COVID‐19 based on computed tomography (CT) scans in real time. Methods We propose an architecture named “concatenated feature pyramid network” (“Concat‐FPN”) with an attention mechanism, by concatenating feature maps of multiple. The proposed architecture is then used to form two networks, which we call COVID‐CT‐GAN and COVID‐CT‐DenseNet, the former for data augmentation and the latter for data classification. Results The proposed method is evaluated on 3 different numbers of magnitude of COVID‐19 CT datasets. Compared with the method without GANs for data augmentation or the original network auxiliary classifier generative adversarial network, COVID‐CT‐GAN increases the accuracy by 2% to 3%, the recall by 2% to 4%, the precision by 1% to 3%, the F1‐score by 1% to 3%, and the area under the curve by 1% to 4%. Compared with the original network DenseNet‐201, COVID‐CT‐DenseNet increases the accuracy by 1% to 3%, the recall by 4% to 9%, the precision by 1%, the F1‐score by 1% to 3%, and the area under the curve by 2%. Conclusion The experimental results show that our method improves the efficiency of diagnosing COVID‐19 on CT images, and helps overcome the problem of limited training data when using deep learning methods to diagnose COVID‐19. Significance Our method can help clinicians build deep learning models using their private datasets to achieve automatic diagnosis of COVID‐19 with a high precision.

There are scanty data on the rate of abnormal Tc-99 m dimercaptosuccinic acid (DMSA) renal scintigraphy and associated factors in children older than 5 years with diagnosis of VUR. We do not have knowledge about which older children should undergo DMSA after VUR diagnosis. This study aims to assess the rate of abnormal DMSA findings and associated factors in children older than 5 years of age diagnosed with VUR. We retrospectively reviewed the medical records of 258 children with VUR diagnosed at or older than 5 year age. 179 children [42 (23.5%) males and 137 (76.5%) females] with complete data were included. 268 reflux units were compared according to gender, bilaterality, grade, reflux phase at voiding cystourethrography, febrile urinary tract infection (fUTI), lower urinary tract dysfunction (LUTD), and DMSA findings with uni- and multivariate analysis. The median age was 110 (60–216) months. VUR grades were I, II, and III in 197 (73.6%) units and IV–V in 71 (26.4%). 138 (51.5%) renal units had abnormal DMSA. VUR grade (p

Theranostics combines diagnosis and targeted therapy, achieved by the use of the same or similar molecules labeled with different radiopharmaceuticals or identical with different dosages. One of the best examples is the use of metaiodobenzylguanidine (MIBG). In the management of neuroblastoma-the most common extracranial solid tumor in children. MIBG has utility not only for diagnosis, risk-stratification, and response monitoring but also for cancer therapy, particularly in the setting of relapsed/refractory disease. Improved techniques and new emerging radiopharmaceuticals likely will strengthen the role of nuclear medicine in the management of neuroblastoma.

Targeting of human epidermal growth factor type 2 (HER2) using monoclonal antibodies, antibody-drug conjugates and tyrosine kinase inhibitors extends survival of patients with HER2-expressing metastatic breast cancer. High expression of HER2 is a predictive biomarker for such specific treatment. Accurate determination of HER2 expression level is necessary for stratification of patients to targeted therapy. Non-invasive in vivo radionuclide molecular imaging of HER2 has a potential of repetitive measurements, addressing issues of heterogeneous expression and conversion of HER2 status during disease progression or in response to therapy. Imaging probes based of several classes of targeting proteins are currently in preclinical and early clinical development. Both preclinical and clinical data suggest that the most promising are imaging agents based on small proteins, such as single domain antibodies or engineered scaffold proteins. These agents permit a very specific high-contrast imaging at the day of injection.

No abstract available

Objective. Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by chronic hypophosphatemia and osteomalacia. We present case of a patient with a protracted clinical course of TIO. TIO profoundly affected every aspect of his life with subsequent profound physical and psychosocial disabilities. Method. The review of a complex clinical presentation, serial laboratory investigations, and imaging modalities of a patient with TIO caused by a mesenchymal tumor. Results. The patient presented with chronic lower back pain, severe bilateral leg weakness, and multiple pathological fractures due to severe osteoporosis. His investigations revealed hypophosphatemia, low 1,25 dihydroxyvitamin D, phosphaturia and normal serum calcium, and parathyroid hormone. Elevated fibroblast growth factor 23 (FGF23) confirmed the diagnosis of TIO and 68Ga-DOTATATE-positron emission tomography/computed tomography (PET/CT) imaging correctly identified a tumor in the left femoral head. His clinical features and biochemical abnormalities promptly recovered after successful surgical resection of the mesenchymal tumor. Conclusion. The present case demonstrated the need to extensively investigate causes of generalized bone pain in patients with hypophosphatemia, as TIO is highly curable. Importantly, 68Ga-DOTATATE PET/CT imaging successfully identified the FGF23 producing tumor, which was undetectable by conventional imaging, favoring its early use in suspected TIO presentation. The present report highlights the importance of timely diagnosis of this complex medical condition, aiming to improve general awareness and enable better clinical outcomes for this rare disorder.

A 15-year-old adolescent girl diagnosed of interaortocaval paraganglioma with a positive 123I-MIGB SPECT/CT and 1 unsuccessful prior surgery was operated on with the assistance of a handheld gamma camera. Once the lesion was located and removed, 2 images were taken, one of the surgical field (without 123I-MIGB uptake) and another of the tumor ex vivo (with high 123I-MIGB uptake), confirming that the lesion had been satisfactorily excised. This case highlights the use of a portable gamma camera as a useful tool to locate this rare tumor, with a SPECT/CT positive for 123I-MIGB and a difficult anatomical location suspected.

BACKGROUND The current diagnostic criteria for temporomandibular disorders (TMD) do not require imaging for the diagnosis of degenerative joint disease (DJD) of the temporomandibular joint (TMJ) condyle, and there is a lack of data investigating the effectiveness of imaging modalities in predicting long-term TMJ DJD prognosis. OBJECTIVES To verify the association between initial bone scintigraphy results and long-term DJD bone changes occurring in the TMJ condyle on cone beam computed tomography (CBCT). METHODS Initial bone scintigraphy, panoramic radiography and CBCT results were analysed in relation to long-term (12 months) TMJ DJD bone change on CBCTs in 55 TMD patients (110 joints). Clinical and radiographic indices were statistically analysed among three groups (improved, no change, and worsened) based on long-term TMJ DJD prognosis calculated by destructive change index (DCI). RESULTS Neither the uptake ratio nor visual assessment results from initial bone scintigraphy showed a significant difference according to long-term condylar bone change groups. The cut-off value of bone scintigraphy uptake ratio was 2.53 for long-term worsening of TMJ DJD. Worsening of TMJ DJD was significantly associated with the diagnosis based on panoramic radiography (p = .011) and CBCT (p

Introduction: The overexpression of somatostatin receptor type 2 (SSTR2) is a unique characteristic of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), which establishes the basis for both diagnosis and therapy. The SSTR status can be evaluated by immunohistochemical staining (IHC) and 68Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) imaging. This study attempted to determine the relationship between IHC and 68Ga-DOTATATE PET/CT imaging and to explore the optimal cutoff value for SSTR IHC reading. Patients and Methods: A total of 100 GEP-NENs with SSTR PET/CT and pathological data were retrospectively analyzed, which consisted of neuroendocrine tumor (NET) G1 (n = 9), NET G2 (n = 64), NET G3 (n = 13), neuroendocrine carcinoma ( n = 10), and mixed neuroendocrine-non-NENs ( n = 4). SSTR2-IHC results were interpreted by 4 well-established semiquantitative scoring systems, including human epidermal growth factor receptor 2 (HER2) score, Volante score, H score, and immunoreactive score. Results: In the homogeneous SSTR2 expression group (accounting for 57% of all cases), the 4 scoring systems were highly concordant with each other (Kendall’s Tau-b coefficient range: 0.80–0.96, p < 0.001) and also highly correlated with the 68Ga-DOTATATE PET/CT imaging results (Spearman’s rank correlation coefficients: 0.71, 0.86, 0.80, and 0.71, p < 0.001). In the heterogeneous group (43%), the 4 scoring systems revealed a lower level of concordance (the Kendall Tau-b coefficient range: 0.40–0.75, p < 0.01), and the correlation with 68Ga-DOTATATE PET/CT imaging was also lower, albeit statistically significant (Spearman’s rank correlation coefficients: 0.53, 0.38, 0.36, and 0.33, p < 0.05). Heterogeneous SSTR2 expression was mainly observed in the HER2 2+ cases, for which the combination with H score could help identify positive cases with increased sensitivity and specificity. The highest sensitivity and specificity of H scores in predicting the imaging results were achieved at 86.10 and 89.30% when defining the cutoff value as 160, indicating that 80% of the tumor cells were moderately positive or 55% were strongly positive. Conclusions: SSTR2 IHC was found to predict 68Ga-DOTATATE PET/CT imaging accurately, especially in the homogeneous expression group. According to the positive 68Ga-DOTATATE PET/CT outcomes, 80% of the tumor cells moderately positive or 55% strongly positive was the cutoff values for SSTR2-IHC reading.

Neuroendocrine neoplasms (NENs) represent a heterogeneous group of tumours. CT or MRI, while being widely available, have recognised limitations for NENs. Consequently, molecular PET/CT imaging plays a fundamental role in NEN diagnosis, detection and characterisation, and has a high management impact, particularly on the selection of patients for radioligand therapy. 68Ga-labelled octreotide derivatives for somatostatin receptor (SSR) imaging are well established for NEN. 18F-FDG (FDG) for imaging tumour metabolic activity, and the dual-tracer imaging approach, are increasingly advocated. The use of other tracers, including [18F]FDOPA and [68Ga]Ga-NOTA-exendin 4, will be outlined. The development of novel radiotracers targeting alternative NEN targets offers promise to further improve NEN detection, characterisation and personalisation of treatments.

Background Targeted axillary dissection (TAD), the combination of sentinel lymph node biopsy (SLNB) and targeted lymph node biopsy (TLNB), can reduce the false negative rates of sentinel node biopsy alone dramatically in breast cancer patients, who received neoadjuvant chemotherapy (NAC). However methods for TAD are still under investigation. Methods Magseed®, a non-radioactive magnetic marker was used to mark the biopsied positive TLN after NAC. The SLNB with the standard technetium-based method and the selective TLNB with Magseed® localization were performed in 40 patients. The TLNs were identified with the Sentimag® probe and excised in all patients. Specimen x-ray was performed to confirm the Magseed® within the prior to NAC biopsied and clipped lymph node. Results The TLN identification rate was 100% (40/40), the SLN identification rate was 82.5% (33/40), the concordance rate between the TLN and the SLN was 65% (26/40). Complications according Magseed® deployment or identification could not be observed. Conclusion Magseed® is a reliable and feasible marker for the identification of TLNs after NAC., Highlights • TLNB is an accurate method for the identification of marked lymph nodes after NAC. • Selective excision of TLNs is feasible. • Magseed® allows a non-radioactive, wireless marking of TLNs.