Nuclear Medicine Techniques Research Articles

The Investigation of Absorbed Dose in Gastroesophageal Reflax Imaging Procedure in Children and Neonates

Introduction: Nuclear medicine techniques have been widely employed in the assessment of gastroesophageal dysfunction. Gastroesophageal reflux (GER) is a common, self-limited process in infants and children that usually resolves at 12 to 18 months of age. Clinical management of GER includes conservative treatment, thickened feedings, positional therapy and parental reassurance. On the other hand, GER disease (GERD) is a less common, more serious pathological process that is manifested by poor weight gain, signs of esophagitis and persistent respiratory symptoms that usually warrant medical management and diagnostic evaluation. photon sources are used for many applications, especially in medicine imaging. Milk scan is used as a sensitive and accurate method for diagnosing GERD in children. The aim of this study is to estimate the amount of absorbed doses in the organs of the stomach, esophagus, and heart of children and infants, who suffer from GERD, using the nuclear imaging. Materials and Methods: By using the computational phantoms of (ORNL) and the MCNPX code in the Monte Carlo method, the absorbed dose of the 99mTc source was calculated as for different age groups. In this test, a certain radiopharmaceutical, which is often Tc99m colloid sulfur, is mixed with the breast milk or milk powder and will be given to the child. After entering the stomach, this radiopharmaceutical will go to an area in the esophagus and will be detected and imaged using the gamma camera. Results: Results from the gamma dosimeter calculation, in which stomach has the highest absorbed dose from photon radiation because this radiopharmaceutical has the maximum accumulation in this organ. it is noteworthy that all the results in this study haven't exceeded the recommended ICRP standards. The obtained results revealed that the absorbed energy fraction in the organs of the esophagus and heart has an inverse relationship with the distance the source organ. The organ, which absorbs the most dose from gamma radiation is stomach and this is expected because we defined the organ in the calculation code as the radiation source. Our study also shows a correlation between the age of the patients investigated and the rate of their absorbed dose, older children showing a absorbed dose is decreased than younger children. Conclusion: The major objective of the present study is to diagnose GERD, using the labeled colloid sulfur radiopharmaceutical with 99mTc, to take the maximum absorbed dose in the stomach and the minimum dose in the organs of the esophagus and heart to create the maximum of effect for imaging and the minimum of complications.

Structural and Functional Magnetic Resonance Imaging of Dementia With Lewy Bodies.

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia after Alzheimer's disease (AD). Although diagnosis may be challenging, there is increasing evidence that the use of biomarkers according to 2017 revised criteria for diagnosis and management of dementia with Lewy bodies can increase diagnostic accuracy. Apart from nuclear medicine techniques, various magnetic resonance imaging (MRI) techniques have been utilized in attempt to enhance diagnostic accuracy. This chapter reviews structural, functional and diffusion MRI studies in DLB cohorts being compared to healthy controls, AD or dementia in Parkinson's disease (PDD). We also included relatively new MRI methods that may have potential to identify early DLB subjects and aim at examining brain iron and neuromelanin.

Pros and Cons of the SeHCAT Test in Bile Acid Diarrhea: A More Appropriate Use of an Old Nuclear Medicine Technique.

Bile acid malabsorption (BAM) causing chronic diarrhea may be due to organic as well as functional disorders, and some of them were included under the general label of diarrheic-type irritable bowel syndrome (IBS-D). The 75-selenium homocholic acid taurine (SeHCAT) test is a nuclear medicine investigation considered to be the gold standard for the diagnosis of bile acid malabsorption (BAM). Many studies demonstrate that it could be effective in the clinical workout of chronic diarrhea due to different conditions. The SeHCAT test provides a quantitative assessment to estimate the severity of BAM and the possible response to therapy with bile acid sequestrants (BASs). However, there is no general agreement regarding its cutoff value and the test is not widely available. The aim of this review is to discuss the advantages and disadvantages of the SeHCAT test in clinical practice.

Antibody-Based Tracers for PET/SPECT Imaging of Chronic Inflammatory Diseases.

Chronic inflammatory diseases are often progressive, resulting not only in physical damage to patients but also social and economic burdens, making early diagnosis of them critical. Nuclear medicine techniques can enhance the detection of inflammation by providing functional as well as anatomical information when combined with other modalities such as magnetic resonance imaging, computed tomography or ultrasonography. Although small molecules and peptides were mainly used for the treatment and imaging of chronic inflammatory diseases in the past, antibodies and their fragments have also been emerging for chronic inflammatory diseases as they show high specificity to their targets and can have various biological half-lives depending on how they are engineered. In addition, imaging with antibodies or their fragments can visualize the in vivo biodistribution of the probes or help monitor therapeutic responses, thereby providing physicians with a greater understanding of drug behavior in vivo and another means of monitoring their patients. In this review, we introduce various targets and radiolabeled antibody-based probes for the molecular imaging of chronic inflammatory diseases in preclinical and clinical studies. Targets can be classified into three different categories: 1) cell-adhesion molecules, 2) surface markers on immune cells, and 3) cytokines or enzymes. The limitations and future directions of using radiolabeled antibodies for imaging inflammatory diseases are also discussed.

Pancreatic VIPomas from China: Case reports and literature review

Vasoactive intestinal polypeptide-secreting tumors (VIPomas) are rare neuroendocrine tumors that often present as watery diarrhea, hypokalemia, and achlorhydria or hypochlorhydria. In this study, we present our institutional experience of diagnosis and treatment of VIPomas, along with a review of the Chinese literature since 1980. Patient #1, diagnosed in 1984 and with intact clinical records, shows the natural history of this disease. Patient #2, diagnosed in 2015, shows the results of evaluation by nuclear medicine techniques and the outcomes of standardized treatment. Comprehensive review of 41 cases allows evaluation of clinical characteristics, treatments and outcomes of pancreatic VIPoma patients. All patients presented with watery diarrhea. The average stool volume reached 3247 mL per day. Average serum VIP level was 839.3 ng/L. Twelve of the 41 cases were reported to have metastases at diagnosis. Somatostatin receptor scintigraphy and 18FDG PET-CT are efficient methods for detection of VIPoma. Surgical excision can promptly alleviate hormonal symptoms.

Treatment of Primary Liver Tumors and Liver Metastases, Part 2: Non-Nuclear Medicine Techniques.

Image-guided procedures are used worldwide in the management of primary liver tumors and liver metastases. These locoregional therapies include local tumor ablation and transarterial therapies and can occasionally downstage an inoperable patient to an operable status. In hepatocellular carcinoma, data have suggested that for tumors smaller than 2 cm ablation may be preferable to surgery. Similar results are emerging for colorectal cancer liver metastases. Catheter-directed therapies such as bland embolization, transarterial chemoembolization, and drug-eluting beads represent potential techniques that can provide survival benefit for inoperable patients. In this review we highlight the most used techniques and the evidence supporting their current indications for the treatment of liver tumors. We briefly review upcoming developments in combination strategies with temperature-sensitive liposomes or immunotherapy for enhancing ablation efficacy.

Uji Klirens dan Uji Pirogenitas sebagai Bagian dari Penentuan Mutu Biologi Sediaan 90Y-EDTMP

Cancer is one of the causes of death in Indonesia and even the world. Nuclear medicine techniques with radiopharmaceuticals and SPECT are one of the ways to treat cancer, but their use in Indonesia is not yet popular. Radiopharmaceuticals marked with radionuclide emitting beta (β) radiation are proven to be used for cancer therapy, one that has been developed in PTRR-BATAN is 90Y-EDTMP. Yttrium-90 is used in nuclear medicine by utilizing β radiation (E max 2.28 MeV). The β energy which is produced from the decay process of 90Y radionuclides to 90Zr can kill cancer cells. This study aimed to provide information about the substances biological effects so that preventive measures can be taken to protect humans. This study conducted evaluation of the 90Y-marked radiopharmaceutical (90Y produced from a 90Sr / 90Y generator which is 90Y-EDTMP) encompasses clearance test, pyrogen test, and dose safety test in experimental animals. The clearance test utilized mice, the pyrogen test utilized rabbits, and the dose safety test utilized mice. The results of the clearance test showed that 90Y-EDTMP compound which was excreted in 192 hour was 49.70% through urine and 14.59% through feces. The total excretion of 90Y-EDTMP within 192 hours was 64.57%. Based on the results of clearance tests with calculations, 90Y of 90Sr / 90Y generators in 90Y-EDTMP dosage form had 84.2 hours of half-life, 36.5 hours of an effective half-life and 52.7 hours of a residence time. Pyrogen test results showed pyrogen-free. The 90Y-EDTMP dose safety test showed that the dose is safe and not deadly. The development of 90Y-EDTMP is expected to be improved to produce radiopharmaceuticals for cancer therapy in order to make a real contribution in public health services.

Role of Recent Imaging Modalities in Diagnosis of Diabetic Foot

Background: osteomyelitis and septic arthritis complicate up to one third of diabetic foot infections that require hospitalization and often result from contaminated soft tissues. Early diagnosis is difficult to achieve through noninvasive imaging studies. Nuclear medicine and radiologic imaging techniques, although commonly used, may lack accuracy. CT is used routinely because it is widely available, but it is of limited diagnostic value in early stages of acute osteomyelitis of the foot and in patients with diabetic osteoarthropathy. MRI, because of its high sensitivity and specificity, is considered the modality of choice for diagnosing osteomyelitis of the foot and for identifying associated soft-tissue abnormalities such as cellulitis, phlegmon, abscess, sinus tracts and ulcers. Aim of the work: this study aimed to assess the role of recent imaging modalities such as high resolution ultrasound, CTA, MRI, MRA and PET/CT in the early detection and /or improving the prognosis of diabetic foot. Conclusion: the major complication facing patients with diabetic foot is amputation that is why tight glycemic control is mandatory. In addition to routine screening for early detection of diabetic foot complications can be helpful. With advancement of radiological techniques, the prognosis of diabetic foot has improved.

CT and MRI of adrenal gland pathologies.

Besides ultrasound and nuclear medicine techniques, computed tomography (CT) and magnetic resonance imaging (MRI) are commonly used to examine adrenal lesions in both symptomatic and asymptomatic patients. Some adrenal lesions have characteristic radiological features. If an adrenal nodule is discovered incidentally, determining whether the lesion is benign or malignant is of great importance. According to their biological behavior, lesions can be divided into benign (mainly: adenoma, hyperplasia, pheochromocytoma, cyst, hemorrhage, cystic lymphangioma, myelolipoma, hemangioma, ganglioneuroma, teratoma) and malignant (mainly: metastases, adrenal cortical carcinoma, neuroblastoma, lymphoma) conditions. In this paper, we review CT/MRI findings of common adrenal gland lesions.

Imaging Guided Breast Interventions.

Breast imaging is a developing field, with new and upcoming innovations, decreasing the morbidity and mortality related to breast pathologies with main emphasis on breast cancer. Breast imaging has an essential role in the detection and management of breast disease. It includes a multimodality approach, i.e. mammography, ultrasound, magnetic resonance imaging, nuclear medicine techniques and interventional procedures, done for the diagnosis and definitive management of breast abnormalities. The range of methods to perform biopsy of a suspicious breast lesion found on imaging has also increased markedly from the 1990s with hi-technological progress in surgical as well as percutaneous breast biopsy methods. The image guided percutaneous breast biopsy procedures cause minimal breast scarring, save time, and relieve the patient of the anxiety of going to the operation theatre. The aim of this review was to describe and discuss the different image guided breast biopsy techniques presently employed along with the indications, contraindication, merits and demerits of each method.

Treatment of Primary Liver Tumors and Liver Metastases, Part 1: Nuclear Medicine Techniques

90Y radioembolization is an increasingly used treatment for both primary and metastatic malignancy in the liver. Understanding the biophysical properties, dosing concerns, and imaging appearance of this treatment is important for interventional radiologists and nuclear medicine physicians to provide important therapy. 90Y radioembolization is efficacious and safe, although the possibility of complications does exist. This article provides a comprehensive in-depth discussion about the indications for 90Y radioembolization, reviews the role of preprocedural angiography and 99mTc-macroaggregated albumin scans, illustrates different dosing techniques, compares and contrasts resin and glass microspheres, and describes potential complications.

An overview of recent developments in FLUKA PET tools

The new developments of the FLUKA Positron-Emission-Tomography (PET) tools are detailed. FLUKA is a fully integrated Monte Carlo (MC) particle transport code, used for an extended range of applications, including Medical Physics. Recently, it provided the medical community with dedicated simulation tools for clinical applications, including the PET simulation package. PET is a well-established imaging technique in nuclear medicine, and a promising method for clinical in vivo treatment verification in hadrontherapy. The application of clinically established PET scanners to new irradiation environments such as hadrontherapy requires further experimental and theoretical research to which MC simulations could be applied. The FLUKA PET tools, besides featuring PET scanner models in its library, allow the configuration of new PET prototypes via the FLUKA Graphical User Interface (GUI) Flair. Both the beam time structure and scan time can be specified by the user, reproducing PET acquisitions in time, in a particle therapy scenario. Furthermore, different scoring routines allow the analysis of single and coincident events, and identification of parent isotopes generating annihilation events. Two reconstruction codes are currently supported: the Filtered Back–Projection (FBP) and Maximum–Likelihood Expectation Maximization (MLEM), the latter embedded in the tools. Compatibility with other reconstruction frameworks is also possible. The FLUKA PET tools package has been successfully tested for different detectors and scenarios, including conventional functional PET applications and in beam PET, either using radioactive sources, or simulating hadron beam irradiations. The results obtained so far confirm the FLUKA PET tools suitability to perform PET simulations in R&D environment.

Current Status of Molecular Imaging in Infections.

There is an increased need to find non-invasive tools for early diagnosis and follow-up of infections. Nuclear medicine techniques may be used to diagnose, localize and evaluate the severity and the extent of infections before the occurrence of anatomical abnormalities. This review focuses on different approaches based on radiolabelled cells, peptides and antibodies or [18F]FDG to image infective diseases in agreement with what is being jointly evaluated by the European Association of Nuclear Medicine (EANM). This is particularly relevant, since the EANM has strated a wide program of collaboration with other European clinical societies to define common diagnostic flow-charts in many of these infective diseases. It emerges the role of radiolabelled WBC by SPECT/CT for prosthetic joint infections and of FDG by PET/CT for spondylodiscitis. Comparable values of accuracy have been described for WBC and FDG in the diagnosis of vascular fgraft infections, diabetic gfoot, endocarditis and peripheral bone osteomyelitis, with some exceptions.

Current Status of Molecular Imaging in Inflammatory and Autoimmune Disorders

In the field of inflammation imaging, nuclear medicine techniques can be considered as a non-invasive tool to early detect pathophysiological changes in affected tissues. These changes usually occur before clinical onset of symptoms and before the development of anatomical changes, that are commonly detected by radiological procedures. This is particularly important for prognostic purposes, therapy decision making and for therapy follow-up. Here we review the current state-of-the art of nuclear medicine for diagnostic purposes in different conditions characterized by a chronic inflammation, such as vulnerable atherosclerotic plaques, vasculitis, rheumatoid arthritis, Sjogren syndrome, autoimmune thyroid diseases, inflammatory bowel diseases, Coeliac disease, Type 1 diabetes mellitus and other immunological diseases. Overall, we describe several different approaches based on radiolabeled cells, peptides and antibodies or FDG. It emerges the role of PET and of hybrid cameras in particular (SPECT/CT and PET/CT) for diagnosis of these disorders and for therapy decision making and followup.

The Role of PET in Monitoring Therapy in Fungal Infections

Positron emission tomography (PET) is a powerful diagnostic nuclear medicine imaging technique. PET allows in vivo detection of a wide variety of physiologic and pathologic phenomena and it offers a noninvasive tool for the monitoring of therapy in various diseases. Invasive fungal infections (IFIs) are a global concern because of the increasing population of patients at risk of IFIs and the high morbidity and mortality. Therapy with antifungal agents is long-standing and expensive. The emerging resistant fungal strains make the management of IFIs challenging. There is an absolute need for a sensitive noninvasive biomarker capable of monitoring the disease activity of IFIs and determining the efficacy of treatment at an early time point. PET imaging with 18F-fluorodeoxyglucose (FDG) was used to detect and assess disease activity in IFI foci already over 20 years ago. At that time, it was suggested it could be a useful biomarker for monitoring antifungal therapy. However, this knowledge has still not been fully exploited for the management of IFIs. The literature reveals an increasing realization of the usefulness of PET in monitoring therapy of IFIs. In this review, we highlight the advantages of nuclear medicine techniques in the management of IFIs with emphasis of the role of PET in monitoring therapy efficacy.

Characterization of hemangioma by nuclear medicine techniques

Characterization of hemangioma by nuclear medicine techniques

NUCLEAR IMAGING IN THE DIAGNOSIS OF CARDIAC AMYLOIDOSIS

Histological analysis of endomyocardial tissue is still the gold standard for the diagnosis of cardiac amyloidosis but has its limitations. Accordingly, there is a need for noninvasive techniques to cardiac amyloidosis diagnostics. Echocardiography and magnetic resonance imaging can show characteristics which may not be very specific for cardiac amyloid. Recently, new opportunities of nuclear imaging in risk stratification and assessment of prognosis for patients with cardiac amyloidosis have appeared. During the last two decades different classes of radiopharmaceuticals have been developed based on compounds tropic to the components of amyloid infiltrates. In this paper we describe the current possibilities and perspectives of nuclear medicine techniques in patients with cardiac amyloidosis, including osteotropic and neurotropic scintigraphy, single-photon and positron emission tomography

Oxygen Sensing, Hypoxia Tracing and in Vivo Imaging with Functional Metalloprobes for the Early Detection of Non-communicable Diseases.

Hypoxia has been identified as one of the hallmarks of tumor environments and a prognosis factor in many cancers. The development of ideal chemical probes for imaging and sensing of hypoxia remains elusive. Crucial characteristics would include a measurable response to subtle variations of pO2 in living systems and an ability to accumulate only in the areas of interest (e.g., targeting hypoxia tissues) whilst exhibiting kinetic stabilities in vitro and in vivo. A sensitive probe would comprise platforms for applications in imaging and therapy for non-communicable diseases (NCDs) relying on sensitive detection of pO2. Just a handful of probes for the in vivo imaging of hypoxia [mainly using positron emission tomography (PET)] have reached the clinical research stage. Many chemical compounds, whilst presenting promising in vitro results as oxygen-sensing probes, are facing considerable disadvantages regarding their general application in vivo. The mechanisms of action of many hypoxia tracers have not been entirely rationalized, especially in the case of metallo-probes. An insight into the hypoxia selectivity mechanisms can allow an optimization of current imaging probes candidates and this will be explored hereby. The mechanistic understanding of the modes of action of coordination compounds under oxygen concentration gradients in living cells allows an expansion of the scope of compounds toward in vivo applications which, in turn, would help translate these into clinical applications. We summarize hereby some of the recent research efforts made toward the discovery of new oxygen sensing molecules having a metal-ligand core. We discuss their applications in vitro and/or in vivo, with an appreciation of a plethora of molecular imaging techniques (mainly reliant on nuclear medicine techniques) currently applied in the detection and tracing of hypoxia in the preclinical and clinical setups. The design of imaging/sensing probe for early-stage diagnosis would longer term avoid invasive procedures providing platforms for therapy monitoring in a variety of NCDs and, particularly, in cancers.

Characterization of 111In-labeled Glucose-Dependent Insulinotropic Polypeptide as a Radiotracer for Neuroendocrine Tumors

Somatostatin receptor targeting is considered the standard nuclear medicine technique for visualization of neuroendocrine tumors (NET). Since not all NETs over-express somatostatin receptors, the search for novel targets, visualizing these NETs, is ongoing. Many NETs, expressing low somatostatin receptor levels, express glucose-dependent insulinotropic polypeptide (GIP) receptors (GIPR). Here, we evaluated the performance of [Lys37(DTPA)]N-acetyl-GIP1-42, a newly synthesized GIP analogue to investigate whether NET imaging via GIPR targeting is feasible. Therefore, [Lys37(DTPA)]N-acetyl-GIP1-42 was radiolabeled with 111In with specific activity up to 1.2 TBq/µmol and both in vitro and in vivo receptor targeting properties were examined. In vitro, [Lys37(111In-DTPA)]N-acetyl-GIP1-42 showed receptor-mediated binding to BHK-GIPR positive cells, NES2Y cells and isolated islets. In vivo, both NES2Y and GIPR-transfected BHK tumors were visualized on SPECT/CT. Furthermore, co-administration of an excess unlabeled GIP1-42 lowered tracer uptake from 0.7 ± 0.2%ID/g to 0.6 ± 0.01%ID/g (p = 0.78) in NES2Y tumors and significantly lowered tracer uptake from 3.3 ± 0.8 to 0.8 ± 0.2%ID/g (p = 0.0001) in GIPR-transfected BHK tumors. In conclusion, [Lys37(111In-DTPA)]N-acetyl-GIP1-42 shows receptor-mediated binding in various models. Furthermore, both GIPR-transfected BHK tumors and NES2Y tumors were visible on SPECT/CT using this tracer. Therefore, [Lys37(111In-DTPA)]N-acetyl-GIP1-42 SPECT seems promising for visualization of somatostatin receptor negative NETs.

ACTUALITIES IN ENDOCRINOLOGY- PARATHYROID IMAGING.

Parathyroid imaging modalities have been used to guide clinicians and surgeons in finding the source of hyperparathyroidism for over 40 years. Primary hyperparathyroidism (PHPT) is generally caused by a parathyroid gland(s) autonomous production of parathyroid hormone (PTH), associated by enlargement of one or more glands. Noninvasive imaging procedures that are used in the management of hyperparathyroidism are anatomical (ultrasound, computer tomography, magnetic resonance imaging) and/or functional (nuclear medicine techniques: planar scintigraphy, single photon emission tomography, positron emission imaging) and/or hybrid imaging.