Search

This study aimed to develop a single photo emission computed tomography/fluorescence (SPECT/FL) bimodal imaging probe to image blood cells. Hyperbranched polyglycerol (HPG) was synthesized by anionic ring-opening polymerization. Succinic anhydride was used to functionalize HPG. Then, indocyanine green (ICG) was bound to HPG, with a 73.59% binding yield. Deferoxamine (DFO) was subsequently bound to ICG-HPG, and DFO-ICG-HPG was radiolabeled with technetium-99m, with 100% yield. The molecular weight of HPG in this study was found to be 6.8 kDa. In in vitro studies, the radiolabeled nanoconjugates remained stable even after 6 h (last timepoint when stability was assessed), and when the nanoconjugates were applied to K562 chronic myeloid leukemia cells, the highest cell viability was observed at a concentration of 5 mu g/mL and binding efficiency increased over time, reaching 30% at 6 h (last timepoint when binding efficiency was assessed). The results support the feasibility of the developed probe to image blood cells, which would be useful for applications such as detecting internal bleeding. [GRAPHICS] ., Ege University Research Fund [2018 FBE 006]; NIH/NCI Cancer Support Grant [P30 CA008748], This work was financially supported by Ege University Research Fund (2018 FBE 006) and partially presented at HEZARFEN International Congress of Science, Mathematics, and Engineering Sciences held in Izmir/Turkey on November 8-10, 2019. Dr. Omer Aras was partially supported through the NIH/NCI Cancer Support Grant P30 CA008748.

Background and Design: Psoriasis is a common chronic inflammatory skin disease believed to affect renal functions. Glomerular filtration rate (GFR) is the most important indicator used to assess renal functions. The present study aims to measure the renal function of psoriasis patients via the technetium-99m diethylenetriamine pentaacetate (Tc-99m DTPA) method and compare the values obtained with those determined through indirect measurement methods, such as the modification of diet in renal disease (MDRD) and chronic kidney disease epidemiology collaboration (CKD-EPI), considering the effects of systemic treatments and comorbidities. Materials and Methods: Eighty-seven patients diagnosed with chronic plaque-type psoriasis vulgaris were included in this study. The patients’ demographic characteristics, disease duration, psoriasis area and severity index score, drugs received for psoriasis treatment, comorbidities, and drugs received for comorbidity treatment were noted. Estimated GFRs were also calculated using the MDRD and CKD-EPI formulas. Results: Tc-99m DTPA values were affected only by age. As the patient age increased, a significant decrease in GFR measured with Tc-99m DTPA (r=0.289, p

Introduction. Overexpression of Her2/neu is detected in 15–20 % of patients with breast cancer and associated with an aggressive form of disease and low overall and disease-free survival rates. Currently, immunohistochemical studies (IHC) and methods of in situ hybridization are used to assess Her2/neu status. One of significant drawbacks of this detection is the impossibility of simultaneous assessment of the receptor status of the primary tumor and metastatic sites. The increasing popularity of radionuclide methods using recombinant proteins as a targeting module have already demonstrated their effectiveness in solving this question at the initial stages of clinical research.The purpose of this study is to demonstrate a clinical case of assessing the extent of breast cancer in a patient with overexpression of Her2/neu using a radiopharmaceutical based on targeted protein molecules labeled with technetium-99m.Description of the clinical case. A patient diagnosed with stage IIIA right breast cancer (T2N2M0), multicentric growth and metastases in right axillary and subclavian lymph nodes at the diagnostic stage was injected intravenously with 99mTc-ADAPT6 radiopharmaceutical. The drug was prepared in the Department of Nuclear Medicine of Research Cancer Institute (Tomsk) immediately before its administration. Planar scintigraphy and singlephoton emission tomography of the chest organs were performed 2 hours after injection of 99mTc-ADAPT6 radiopharmaceutical. In addition to the previously described tumors, 3 foci of hyperfixation of the tracer in the projection of the 5th rib on the right along the middle-clavicular line, as well as in the projection of the 8 and 9 thoracic vertebrae (Th VIII, IX) were found. Computed tomography of the chest organs and bone scintigraphy with 99mTc-pyrophosphate showed no metastases in the 5th rib on the right and Th VIII, IX. Magnetic resonance imaging of the thoracic spine revealed 2 metastatic foci in Th VIII, IX. Planar scintigraphy with 99mTc-pyrophosphate and CT performed 6 months after injection of 99mTc-ADAPT6 revealed previously described foci in the projection of the thoracic spine (Th VIII, IX) and 5 ribs on the right along the mid-clavicular line. Conclusion. The results demonstrated during the study suggest that 99mTc-ADAPT6 is a promising tracer for molecular imaging of tumor foci with overexpression of the Her2/neu receptor in breast cancer patients.

The aim of this study was to estimate and subsequently measure the occupational radiation exposure for all personnel involved in producing, administering, or performing imaging or surgery with [99mTc]Tc-PSMA-I&S, which has been introduced for identification of tumor-positive lymph nodes during salvage prostate cancer surgery. Methods: The effective dose was estimated and subsequently measured with electronic personal dosimeters for the following procedures and personnel: labeling and quality control by the radiopharmacy technologist, syringe preparation by the nuclear medicine laboratory technologist, patient administration by the nuclear medicine physician, patient imaging by the nuclear medicine imaging technologist, and robot-assisted laparoscopic salvage lymph node dissection attended by an anesthesiology technologist, scrub nurse, surgical nurse, and surgeon. The dose rate of the patient was measured immediately after administration of [99mTc]Tc-PSMA-I&S, after imaging, and after surgery. Results: The estimated dose per procedure ranged from 1.59 × 10-10 μSv (imaging technologist) to 9.74 μSv (scrub nurse). The measured effective dose ranged from 0 to 5 μSv for all personnel during a single procedure with [99mTc]Tc-PSMA-I&S. The highest effective dose was received by the scrub nurse (3.2 ± 1.3 μSv), whereas the lowest dose was measured for the surgical nurse (0.2 ± 0.5 μSv). If a single scrub nurse were to perform as many as 100 procedures with [99mTc]Tc-PSMA-I&S in a year, the total effective dose would be 320 μSv/y. Immediately after administration, the dose rate at 50 cm from the patient was 18.5 ± 1.6 μSv/h, which dropped to 1.8 ± 0.3 μSv/h after imaging the following day, reducing even further to 0.56 ± 0.33 μSv/h after surgery. Conclusion: The effective dose for personnel involved in handling [99mTc]Tc-PSMA-I&S is comparable to that of other 99mTc-radiopharmaceuticals and therefore safe for imaging and radioguided surgery.

Recently, the applicability of somatostatin receptor-targeted (SSTR-t) radiotracers for post-ischemic myocardial inflammation imaging has been shown using PET. Currently, there are no studies which demonstrate ability of SPECT and technetium-99m SSTR-t radiotracers to detect inflammation, which appears in response to acute myocardial infarction (AMI). A case of 51-year-old male with acute anterior myocardial infarction (AMI) with ST elevation has been presented. This patient on 7th day after AMI onset underwent SPECT/CT (by cardiac cadmium-zinc-telluride gamma-camera) with 99mTc-Tectrotide, cardiac MRI with gadolinium and, on 9th day after AMI, myocardial perfusion scintigraphy (MPS) at rest. Clear myocardial uptake of 99mTc-Tectrotide, predominantly in apical and intermediate anterior wall of left ventricle was detected. The uptake matched with areas of hypoperfusion (by SPECT) and myocardial injury (by MRI). This case demonstrated the applicability of technetium-99m-labeled SSTR-t radiotracers for post-infarction inflammation imaging. Currently assumed, that SSTR-t radiotracers reflect an increased number of activated macrophages infiltrating infarcted myocardium, which is not possible using any other imaging technique. Thus, potentially, SSTR scintigraphy may be useful for diagnosis and monitoring of myocardial post-infarction inflammation as well as for anti-inflammatory image-guide therapy assessment.

Nodular regenerative hyperplasia (NRH) of the liver may lead to noncirrhotic portal hypertension with subsequent development of portosystemic shunts. While extrahepatic and macrovascular shunts are readily visualized with imaging or endoscopy, there is no standard technique to detect intrahepatic microvascular portosystemic shunting and quantitatively assess shunt burden. We present a case of a 53-year-old female with suspected NRH and hepatopulmonary syndrome with inconclusive liver biopsies and absent portosystemic shunts per abdominal imaging. A percutaneous transportal infusion of Technetium-99m labeled macroaggregated albumin (99mTc-MAA) successfully identified intrahepatic microvascular portosystemic shunting and quantified a lung shunt fraction of more than 30%. NRH was subsequently confirmed with a surgical wedge biopsy and the patient was successfuly treated with a liver transplant. Transportal 99mTc-MAA could be used to both identify and quantify otherwise occult microvascular portosystemic shunts in patients with clinical sequelae of portal hypertension.

Patients who underwentQuantitative assessment of myocardial radiotracer activity with CPA or VOI have high diagnostic accuracy for ATTR-CM. Both measures are potential non-invasive markers to follow progression of disease or response to therapy.Las imágenes deLa evaluación cuantitativa de la actividad del radiotrazador en miocárdico con CPA o VOI tiene una alta certeza diagnóstica para ATTR-CM. Ambas medidas son potenciales marcadores no invasivos para seguir la progresión de la enfermedad o la respuesta a terapia.背景:L’imagerie au 99mTc-pyrophosphate est devenue une méthode non invasive importante pour le diagnostic de l’amyloidose cardiaque à transthyrétine (ATTR-CM). La quantification de l’activité du 99mTc-pyrophosphate sur les images SPECT, pourrait être un marqueur de l’intensité de la maladie. Dans cette étude, nous avons évalué la précision diagnostique et la signification clinique de la quantification au 99mTc-pyrophosphate. MéTHODES ET RéSULTATS: Les patients ayant bénéficié d’une imagerie au 99mTc-pyrophosphate pour suspicion d’ATTR-CM ont été inclus. Nous avons calculé l’activité (CPA) et le volume (VOI) du 99mTc-pyrophosphate (CPA) au niveau du myocarde sur les images SPECT en rapport à l’activité sanguine au niveau de la cavité ventriculaire gauche. La précision du test a été évaluée en utilisant la surface (AUC) sous la courbe ROC. Au total, 124 patients ont été étudiés (âge moyen de 73,9 ± 11,4). Quarante trois de ces patients (34.7%) furent diagnostiqués positivement pour l’ ATTR-CM. La précision diagnostique de la CPA s’est révélée la plus élevée (AUC 0,996, IC à 95% 0,987 - 1,00), et s’est avérée significativement plus élevée que le score de Perugini (AUC 0,952, p = 0,016). Chez les patients avec ATTR-CM, la CPA est associée à une fraction d’éjection ventriculaire gauche réduite (odds ratio ajusté de 1,28, p = 0,035) et une augmentation d’ hospitalisation pour insuffisance cardiaque (hazard ratio ajusté de 1,29, p = 0,006).L’évaluation quantitative de l’activité du 99mTc-pyrophosphate est d’une grande précision diagnostique pour l’ ATTR-CM. Les mesures CAP et VOI sont des marqueurs non invasifs potentiels pour le suivi de la progression de la maladie ou réponse au traitement.

Objective To determine the frequency of pyramidal lobe remnants after total thyroidectomy (TT) and the effect on stimulated thyroglobulin (Tg). Methods The study included 1740 differentiated thyroid cancer (DTC) patients who were followed up by our center. The department database was searched to identify DTC patients with residual pyramidal lobe after TT. All postoperative technetium-99m pertechnetate thyroid scintigraphy images were re-evaluated for pyramidal lobe residue. Serum stimulated Tg and thyroid stimulating hormone (TSH) levels measured within the first 6 months after TT were retrieved from the database. Results Pyramidal lobe residue was detected in 10.4% of the patients who underwent TT. Evidence of the pyramidal lobe was present on preoperative ultrasonography in 1.6% of the patients with residual pyramidal lobe. Stimulated Tg in patients with pyramidal lobe residue was significantly higher than that in patients without residue (P = .01). Endogenous stimulated TSH in patients with residual pyramidal lobe was significantly lower than that in patients without residue (P = .036). In 5.7% of patients with pyramidal lobe residue, a TSH level of >30 mIU/L was not achieved, which was a significantly higher rate than that in patients without pyramidal lobe residue (P = .034) and is the level required for maximum radioiodine uptake. Conclusion Pyramidal lobe residue was found in almost 10% of DTC patients. The pyramidal lobe is often missed on preoperative ultrasonography. Residual pyramidal lobe increased stimulated Tg and decreased endogenous stimulated TSH. Residual pyramidal lobe may complicate the follow-up of DTC patients.

We studied an original radiolabeled complex of antimicrobial peptides UBI29-41 and UBI18-35, ubiquicidin derivatives, for distinguishing between bacterial and aseptic inflammation. For radiolabeling of the peptides with technetium-99m, a bifunctional chelating agent succinimide-1-yl 6-(bis(pyridin-2-ylmethyl)amino)hexanoate was used. The obtained complexes 99mТс-DPAH-UBI29-41 and 99mТс-DPAH-UBI18-35 had radiolabeling yield >80% and radiochemical purity >96%. Accumulation of the complexes in the focus of bacterial inflammation in bone structures and the absence of this complex in the site of aseptic inflammation was confirmed in a rat model of traumatic osteomyelitis by single-photon emission computed tomography.

In the 1980s, 201Tl scintigraphy helped to introduce noninvasive assessment of myocardial perfusion as an important clinical tool for the detection and management of coronary artery disease (CAD). Monovalent cations such as 201Tl exhibit pharmacokinetics that are very suitable for the assessment of

Introduction. Skin cancers came first in Russia in numbers of oncological diseases. Melanoma, making up only a small part of these cases, leads to the most serious consequences. The nuclear medicine methods application is necessary at the stages of clarifying the diagnosis, searching for remote metastases and the treatment monitoring. The work is devoted to one of the stages of the radiopharmaceutical development for the diagnostics of malignant melanoma and its metastases based on the synthetic analog of α-melanocyte stimulating hormone (SAH) and radionuclide Tc-99m.Aim. The selection of optimal conditions for the preparation of the SAH ∙ 99mTc complex and the study of the using possibility it as a diagnostic tool in in vitro experiments.Materials and methods. Experimental work was carried out to optimize the conditions for obtaining the complex compound SAH ∙ 99mTc. The binding and internalization of this compound by B16-F0 melanoma cells has been studied.Results and discussion. The results of labeling SAH with a 99mTc radionuclide under a wide range of conditions were obtained both by the direct method and using the intermediate complex. The target compound rapidly binds to B16-F0 melanoma cells. The degree of internalization is more than 85 %.Conclusion. Based on the results of chemical experiments and data from in vitro experiments, optimal conditions for obtaining a complex compound SAH ∙ 99mTc with a radiochemical yield of more than 90 % were found. The mechanism of binding of this compound to malignant melanoma cells has been established.

Background: As the treatment approaches of Graves’ disease (GD) and thyroiditis are different, the differential diagnosis is essential. Aim: To assess the diagnostic value of free triiodothyronine (FT3) to free thyroxine (FT4) ratio for differentiation between GD and destructive thyroiditis. Subjects and Methods: The present study was conducted on 100 newly diagnosed thyrotoxicosis patients; 61 with thyroiditis (group 1) and 39 with GD (group 2) and 20 healthy, age-matched subjects representing a control group (Group 3). All participants underwent medical history taking and clinical examination, serum levels of thyroid-stimulating hormone (TSH), FT3, and FT4 were measured, Technetium 99m thyroid Scan was done to all recruited patients. Results: The present results recorded significant increases in FT3, FT4, and decreases in TSH levels in Graves’ disease group than in the thyroiditis group. There was a statistically significant difference between the study groups regarding FT3/FT4 ratio, which was lower in thyroiditis group than in Graves’ disease group (0.21± 0.03 in group 1 vs 0.35±0.18 in group 2, p-value

Background Little is known about factors that influence the efficacy of transarterial radioembolization (TARE). Purpose To determine the relationship between tumor radiation-absorbed dose and survival and tumor response in locally advanced inoperable hepatocellular carcinoma treated with TARE. Materials and Methods This was a secondary analysis of prospectively acquired data (between December 2011 and March 2015) from participants who received TARE in the Sorafenib versus Radioembolization in Advanced Hepatocellular Carcinoma (SARAH) trial (ClinicalTrials.gov identifier: NCT01482442). Tumor-absorbed dose was computed using technetium 99m (99mTc) macroaggregated human albumin (MAA) SPECT/CT. Visual agreement among CT, 99mTc-MAA SPECT/CT, and yttrium 90 (90Y) SPECT/CT or PET/CT was scored as optimal, suboptimal, or not optimal. Overall survival (OS) and tumor response at 6-month follow-up CT (Response Evaluation Criteria in Solid Tumors, version 1.1) were assessed. OS was evaluated using Kaplan-Meier tests. A propensity score comparing participants receiving a tumor dose greater than or equal to 100 Gy (best cut-off according to the receiver operating characteristic curve and median tumor radiation-absorbed dose values in the study groups) with those receiving sorafenib was calculated. Results One hundred twenty-one participants (median age, 67 years; interquartile range [IQR]: 61-73 years; 110 men) were evaluated in the dose-survival group, and 109 (median age, 66 years; IQR: 61-71 years; 100 men) were evaluated in the dose-tumor response group. In the dose-survival group, median OS was 9.3 months (95% confidence interval [CI]: 6.7 months, 10.7 months), and median tumor radiation-absorbed dose was 112 Gy (IQR: 68-220 Gy). Participants who received at least 100 Gy (n = 67) had longer survival than those who received less than 100 Gy (median, 14.1 months [95% CI: 9.6 months, 18.6 months] vs 6.1 months [95% CI: 4.9 months, 6.8 months], respectively; P < .001), and those with optimal agreement (n = 24) had the longest median OS (24.9 months; 95% CI: 9.6 months, 33.9 months). In the dose-tumor response group, tumor radiation-absorbed dose was higher in participants with disease control versus those with progressive disease (median, 121 Gy [IQR: 86-190 Gy] vs 85 Gy [IQR: 58-164 Gy]; P = .02). The highest disease control rate was observed in 31 of 40 participants (78%) with a tumor radiation-absorbed dose greater than or equal to 100 Gy and optimal agreement. Conclusion Higher tumor radiation-absorbed dose computed at technetium 99m macroaggregated human albumin SPECT/CT was associated with better overall survival and disease control in hepatocellular carcinoma treated with transarterial radioembolization with yttrium 90 in the Sorafenib versus Radioembolization in Advanced Hepatocellular Carcinoma trial. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Sofocleous and Kamarinos in this issue.

Radionuclide whole-body bone scan is a useful investigation of choice to detect the skeletal metastases in prostate cancer. It is indicated in patients having elevated serum prostate-specific antigen (Sr. PSA) or patients with bone pain. Elevated Sr. PSA levels have high predictive value for skeletal metastases; however, there is no consensus regarding cut-off value of Sr. PSA above which bone scan is indicated. This study was performed to find out the accuracy of Sr. PSA test and to know the optimal cut-off value of Sr. PSA with high sensitivity and specificity in the prediction of skeletal metastases on bone scan in prostate cancer patients. A retrospective analysis of medical records of 307 prostate cancer patients referred to the department of nuclear medicine for bone scan between June 2009 and June 2014 was done. Of 307 patients, 15 cases were excluded due to nonavailability of Sr. PSA. Bone scan was performed 3 h after administration of 20 mCi Tc-99m methylene diphosphonate intravenously. Whole-body sweep imaging was performed and spot views were taken wherever required. Of 292 cases, 174 (59.58%) patients had positive bone scan for metastases and 118 (40.41%) patients had negative bone scan for metastases. Maximum and minimum Sr. PSA levels in positive and negative bone scan patients were 1260 and 0.02 ng/ml and 198.34 ng/ml and 0.01 ng/ml, respectively. On comparison of the mean Sr. PSA levels between positive and negative groups, we found significant Sr. PSA levels (P < 0.05). We used receiver operating characteristic (ROC) curve analyses to find out the accuracy of Sr. PSA test and to know the optimal cut-off value of Sr. PSA with maximum sensitivity and specificity in the prediction of skeletal metastases on bone scan. Area under ROC curve was 0.878 (87%). This indicates that the accuracy of Sr. PSA test in the prediction of skeletal metastases on bone scan was good. The optimal cut-off value of Sr. PSA in the prediction of positive bone scan for skeletal metastases in the management of prostate cancer was 29.16 ng/ml, with sensitivity and specificity of 89.0% and 74.6%, respectively. In this study, we conclude that the accuracy of Sr. PSA test in the prediction of skeletal metastases is good. ROC-derived optimal cut-off value of Sr. PSA for positive skeletal metastases on bone scan is >29.16 ng/ml; thus, the chances of getting positive bone scan for skeletal metastasis are less in prostate cancer patients with Sr. PSA

Bone scans differentiate transthyretin (ATTR) cardiac amyloidosis from light chain amyloidosis and other causes of increased left ventricular (LV) wall thickness. We examined the prevalence and implications of cardiac uptake in the general population. Patients were included based on having undertaken a bone scan for non-cardiac indications using Technetium 99m hydroxymethylene diphosphonate (HMDP) or Technetium 99m methylene diphosphonate (MDP). Blinded image review was undertaken. Positive was defined as cardiac uptake ≥ rib AND heart/whole body ratio (H/WB) > 0.0388. Echocardiography and clinical records were reviewed. 6918 patients were included. 15/3472 HMDP scans were positive (14 males, 1 female): none in individuals aged

Background: Soft tissue and bone infection and neuro osteoarthropathy involving the foot are the most common long-term complications of diabetes mellitus, implying a serious impairment in quality of life for patients in the advanced stages of the disease. Both pathologies often coexist and differentiating between them is crucial because the management may differ substantially. Misdiagnosis may result in high morbidity for the patient such as unnecessary limb amputation. Diagnosis is largely based on clinical signs supplemented by various imaging modalities such as radiography, MR imaging, and hybrid imaging techniques such as F-18 fluorodeoxyglu-cose-positron emission tomography and nuclear imaging studies. Aim of Study: The aim of this study is to evaluate the diagnostic value of MRI and technetium-99m Hexamethyl-propylene Amine Oxime (HMPAO) labeled leukocyte scin-tigraphy in the diagnosis and differentiation between acute osteomyelitis and neuroarthropathy in the diabetic foot. Patients and Methods: The study included 35 patients (20 men and 15 women) aged 62±8.8 years having diabetes mellitus and a total of 43 clinically suspicious infection sites. The basic exploration included standard radiography, three-phase bone scintigraphy and 99mTc-HMPAO Leucocyte Scan (HMPAO-LS) and pre and post contrast enhanced MRI. 16 bone and 10 soft tissue biopsies were obtained from ulceration sites. Clinical follow-up as well as scintigraphy and MRI performed 4 months after initial diagnosis and 1 month after antibiotic withdrawal were performed in suspected osteomy-elitis cases. Results: Among the 43 sites, 23 sites were finally diag-nosed as osteomyelitis. No osteomyelitis was present at 20 sites, of which 9 sites were diagnosed as cellulitis and 11 as neuropathic ulcers based on combined clinical, imaging, pathologic findings and follow-up. The sensitivity and specif-icity of MRI were (95% and 85%) and of Labeled leucocyte scanning were (87% and 90%) respectively.Conclusion: The combined use of 99mTc-HMPAO-LS and MRI yielded higher diagnostic efficacy in diabetic foot related complications.

Complicated Meckel's diverticulum (MD) in pediatric age group may not present with classic symptoms or signs. The routine modalities of investigations for the detection of MD are ultrasonography (US), computerized tomography, and air enema. However, these may miss the diagnosis in cases of atypical patterns of presentation. In such situations, the radionuclide Meckel scan helps to narrow down the diagnosis. The objective of this case report was to present an unusual presentation of MD where the diagnosis was established by a radionuclide scan against other methods which were equivocal. An 8-year-old boy was admitted with features of intestinal obstruction.99mTc-pertechnetate Meckel's scintigraphy showed localization of tracer in ectopic gastric mucosa. The surgical exploration after the Meckel's scan revealed a curve-shaped MD localized 50 cm proximal to the ileocecal valve. The surgery was completed after a diverticulectomy, and the patient was relived of symptoms. MD scintigraphy can help detect ectopic gastric mucosa in cases of unusual presentation by considering the atypical presentation, variation in shape, and location on Meckel's scan and improve the disease management.

AIM To investigate the diagnostic ability of maximum standardised uptake value (SUVmax) at combined single-photon-emission computed tomography/computed tomography (SPECT/CT) for the evaluation of osteonecrosis of the jaw. MATERIALS AND METHODS Seven patients with mandibular osteonecrosis (three osteoradionecrosis, three medication-related osteonecrosis of the jaw (MRONJ), and one rheumatoid arthritis) underwent SPECT/CT at 4 hours after injection of technetium 99m hydroxymethylene diphosphonate. The SPECT/CT parameters SUVmax were compared for the osteonecrosis with normal mandible. Statistical analyses among the SUVmax of osteonecrosis were performed by one-way repeated measures analysis of variance with Tukey's HSD (honestly significant difference) test. A p-value RESULTS SUVmax for MRONJ and rheumatoid arthritis (23.24±8.63) were significantly higher than those for osteoradionecrosis (9.05±1.39, p=0.005) and normal mandible (3.57±0.46, p=0.000). CONCLUSIONS SUVmax derived from bone SPECT/CT could be useful for the evaluation of osteonecrosis of the jaw.

We report herein a case of a 40-year-old male patient with chronic renal failure presenting a severe hyperparathyroidism with an elevation of parathormone level evaluated in nuclear medicine department for MIBI-Technetium-99m parathyroid scintigraphy. The parathyroid scintigraphy revealed the appearance of a preferential fixation of the MIBI-99mTc opposite the lower left pole of the thyroid and opposite the upper part of the right hemi thorax. A subsequent single-photon emission computed tomography-computed tomography focused on the cervico-thoracic region was performed and showed an ectopic parathyroid adenoma associated with an incidental brown tumor mimicking bone and lung metastases. Our case report confirms the usefulness of additional hybrid SPECT-CT imaging in the management of hyperparathyroidism.

Background Speckle tracking echocardiography (STE) may be useful for the detection of subclinical systolic function abnormalities. Dynamic acquisition of myocardial blood flow using 99mTc-MIBI SPECT-CZT gamma camera allows the calculation of coronary flow reserve (CFR). Purpose The aim of our study is to assess the relationship between left ventricular longitudinal strain (LS) and CFR in patients with suspected coronary artery disease (CAD). Methods 55 patients (pts) (43.6% females, mean age 64.6±8.4 years) with suspected CAD underwent transthoracic echocardiography with assessment global and local LS by STE. We calculated mean global left ventricular LS (GLS), as well as LS of individual coronary artery territories (LAD LS, LCx LS and RCA LS). All pts underwent myocardial perfusion study with novel solid-state CZT nuclear camera (dipyridamole stress protocol). We measured CFR of the left ventricle and individual coronary territories. Results Mean absolute GLS in pts with total CFR 2 (median value −13.9 vs −18.3; p (−15.8) – its sensitivity was 68%, specificity 77.7%, and overall accuracy 73%. Conclusions Indices of left ventricular longitudinal function obtained by speckle tracking echocardiography correlate with SPECT-derived CFR in patients with suspected CAD. Funding Acknowledgement Type of funding sources: None.

Objective To investigate a mechanistic determinant of left atrial (LA) reservoir function in patients presenting left ventricular (LV) hypertrophy, and clarify diagnostic and prognostic values of LA reservoir strain in patients with cardiac amyloidosis (CA). Methods Three-hundred sixty patients (median age: 68 years, male gender: 65%) with left ventricular hypertrophy (LVH) assessed by echocardiography were retrospectively included. The LVH etiologies were diagnosed by any of biopsy, cardiac magnetic resonance imaging or 99mTc-PYP scintigraphy. LV segmental longitudinal strain was estimated from apical three views, and LA reservoir strain was measured from an apical 4-chamber view. Results The LVH etiologies were confirmed with CA in 81 patients, hypertensive heart disease in 87 patients, hypertrophic cardiomyopathy in 143 patients, and miscellaneous disorders in 49 patients. The median (25th, 75th percentile) value of LV ejection fraction was 59% (48–67). LV basal longitudinal strain and LA reservoir strain were significantly reduced in patients with CA compared with those with other etiologies; LV basal strain: 5.4% (3.9–8.7) vs. 11.9% (9.3–14.6), LA reservoir strain: 9.2% (6.3–12.3) vs. 17.5% (11.3–24.1), p Conclusions The decrease of LV longitudinal shortening at cardiac base could worsen LA reservoir function especially in patients with CA. LA reservoir strain might be an alternative measure to identify CA etiology and have a predictive value of heart failure hospitalization in patients with LV hypertrophy. Funding Acknowledgement Type of funding sources: None.

Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Pfizer Research Grant (ID#57165999) Background Misfolding of transthyretin (TTR) is the source of two distinct forms of amyloidosis (ATTR): acquired or wild-type (ATTRwt) and hereditary (ATTRm), which is transmitted in an autosomal dominant inheritance with a variable penetrance. Types of transthyretin (TTR) gene mutations display genetic and ethnic variability. Purpose The aim of this prospective study was to assess the TTR gene variants, echocardiographic parameters and regional left ventricle 99mTc-DPD uptake among patients with ATTR and first-degree relatives. Methods We present data based on evaluation of first 25 patients (13 (52%) females), including 10 (40%) index patients with ATTR (age 66.4 ± 13 years) and 15 (60%) first-degree relatives who were studied between June 2020 and February 2021. Analysis included clinical data, free light chain blood immunoglobulins and urine immunofixation, transthoracic echocardiography (TTE) with global longitudinal strain (GLS) analysis, single-photon emission computed tomography (SPECT) with 3,3-disphono-1,2-propanodicarboxylic acid (DPD), genetic testing by an amplicon-based next-generation TTR sequencing approach, and in selected cases cardiac or soft tissue biopsy. Results Overall, 6 index patients were diagnosed with ATTRm and 4 with ATTRwt presenting mixed, cardiac or neuropathic phenotype. There were detected following types of TTR variants - Phe53Leu, Ala101Val, Glu112Lys, Glu109Lys. Nine out of 10 index patients were diagnosed with amyloid cardiomyopathy (CA) with grade 2-3 tracer uptake in SPECT and symptomatic heart failure (NYHA 2.2 ± 1.1; NT-proBNP value 2224 ± 2799 pg/ml). In both ATTRm and ATTRwt there were patients presenting with either focal or diffuse tracer pattern evaluated by SPECT technique. In TTE there was marked left ventricle (LV) hypertrophy with maximum wall thickness of 22 ± 5 mm and LV mass value index value of 382 ± 111 g/m2. All patients with CA had abnormal global longitudinal strain (GLS, -14.5 ± 5%) and diastolic dysfunction (EA 1.56 ± 0.76, E/E’ 16 ± 11). None of relatives expressed tracer uptake in scintigraphy. Overall, 5 first-degree relatives were diagnosed with Phe53Leu variant, among them two patients presented with decreased GLS value. Conclusions Patients with ATTR presented in TTE with LV hypertrophy, decreased GLS value, diastolic dysfunction and grade 2-3 in scintigraphy with either focal or diffuse tracer uptake in SPECT technique. None of first-degree relatives expressed increased tracer uptake in scintigraphy. However, some of relatives who were diagnosed with pathogenic TTR variant presented with decreased GLS value.

Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Universitary Clinic Hospital of Valencia Aim Cardiac uptake of 99mTc-DPD has proved its diagnostic efficacy in transthyretin cardiac amyloidosis(ATTR). We compared the usual visual assessment with two quantitative methods to evaluate cardiac activity and its possible relation with clinical follow-up. Methods We have studied 37 successive patients(p):32 men, 52-90 y/o (79.6 ± 9.3), submitted by suspected cardiac amyloidosis TTR by echo/cardiac MRI. After IV administration of 21.5 ± 3.4mCi of 99mTc-DPD, we obtained early (at 5min) and late (at 3h) whole body(WB) planar images and late SPECT. We assessed cardiac uptake in planar images by visual score (0-absent, 1-cardiac uptake lower than bone uptake, 2-equal, 3- higher than bone uptake), considering 2-3 score compatible with ATTR in absence of abnormal light chains on serum-urine. We obtained quantitative evaluation by heart/contralateral thoracic activity ratio (H/CL) in late images and from early and late WB images the heart retention(HR) ratio and heart/whole body(HWB) activity ratio. Clinical follow-up (12.4 ± 8.3 months) considering as cardiac events(CE): cardiac death and heart failure(HF) admissions. Results Visual score 0(11p), 1(2p), 2(4p) and 3(20p), considering group1(0-1) not suggestive of ATTR and group2(2-3) compatible with ATTR. SPECT showed biventricular uptake with septal predominance in group2. H/CL index was 2.23 ± 0.54(group2) vs 1.05 ± 0.10(group1) p Conclusion We have found excellent correlation between visual score and the evaluated methods of quantitation of 99mTc-DPD cardiac uptake in our patients referred by suspected cardiac amyloidosis. These quantitative methods could be a helpful tool to correctly identify some patients with doubtful activity and could be useful in the follow-up evaluation, although it is necessary to study a greater number of patients.

Currently the development of technologies for labeling somatostatin with technetium-99m for diagnosing radionuclide neuroendocrine tumors is under way. Somatostatin analogues are binded with technetium99m only by the preliminary addition of a chelating agent. Therefore, it is important to develop a method for preparation of an octreotide derivative by modifying octreotide with precursors: ligands with high chelating ability for its tight binding with technetium-99m. ω-Bis(pyridin-2-ylmethyl)amino)aliphatic acids can be used successfully as such precursors.The purpose of the study was to develop a method for obtaining a new octreotide derivative for diagnosing neuroendocrine tumors.Materials and methods. The somatostatin octreotide analogue was used as the object of the study; succinimid-1-yl 6-(bis(pyridin-2-ylmethyl)amino)hexanoate was used as a chelating agent. Methods of high performance liquid chromatography and mass spectrometry were used to separate and analyze the synthesized compounds.Results. A method to produce an original octreotide derivative using a succinimid-1-yl 6-(bis(pyridin2-ylmethyl)amino)hexanoate as a chelating agent was proposed. The conditions of analytical and semipreparative HPLC for the analysis and purification of the active octreotide derivative (a monosubstituted derivative of the amino acid residue of D-phenylalanine) were suggested.Conclusion. The synthesized derivative of octreotide has a chelating center for strong binding to technetium-99m in its structure, which can be useful for diagnosing neuroendocrine tumors.

Here we reported the development of a novel immuno-SPECT tracer, namely 99mTc-JS001, to non-invasively image PD-1 expression in mice. The JS001 antibody was directly labeled by the most widely used SPECT radionuclide 99mTc with a radiochemical yield of 90%, and the specific activity was ≤74 GBq/mmol. After the radiolabeling, 99mTc-JS001 exhibited a similar immnuoaffinity to PD-1 in vitro. 99mTc-conjugated JS001 maintained intact in 5% HSA system for 24 h. S180 sarcoma xenograft-bearing Kunming mice and BGC823 gastric cancer orthotopic tumor model were built. Bio-distribution and/or immuno-SPECT studies with 99mTc-JS001 showed the antibody maintained in the blood, liver, kidneys and tumors at 1.5 ID%/g, 1.4 ID%/g, 2.0 ID%/g and 0.5 ID%/g, respectively. Also, there was a higher uptake in the BGC823 orthotopic tumor than that in the adjunct stomach. These results demonstrated that 99mTc-JS001 might have capacity to monitor the PD-1 expression in vivo, which might facilitate the anti-PD-1 antibodies treatment in preclinical models.

This study aimed to evaluate fused images of single-photon emission computed tomography/computed tomography (SPECT/CT), stand-alone whole-body scintigraphy (WBS) and stand-alone CT in the diagnosis of post-traumatic chronic-infected nonunion osteomyelitis (OST) of the lower limb.The imaging data from 144 patients with known/suspected chronic-infected fracture nonunion in the lower limbs following internal/external fixation between June 2015 and December 2017 were reviewed retrospectively. Technetium-99m-methylene diphosphonate SPECT/CT scans were performed on the patients. For each patient, the diagnosis on the basis of each imaging approach was classified as yes (OST), no (no OST), or equivocal by experienced nuclear medicine physicians and radiologists. An intraoperative bacterial culture experiment was conducted as our gold standard. The diagnostic sensitivity, specificity, accuracy, positive predictive value, negative predictive value, κ coefficient, significance level, and agreement level were analyzed.The diagnosis on the basis of SPECT/CT fused images showed a sensitivity of 91.3%, a specificity of 84.6%, and accuracy of 88.9% compared to that based on WBS, with a sensitivity of 52.2%, a specificity of 15.4%, accuracy of 38.9%, and CT, with a sensitivity of 65.2%, a specificity of 23.1%, accuracy of 50.0%. The fused images can show the precise sites of post-traumatic chronic-infected OST. Considerable agreement (κ 0.679) was found between the SPECT/CT diagnosis and an intraoperative bacterial culture test (WBS, κ 0.218; CT, κ = 0.184).Technetium-99m-methylene diphosphonate SPECT/CT imaging fusion can improve diagnostic confidence for post-traumatic patients with chronic nonunion OST. This imaging approach can achieve an accurate diagnosis by revealing the precise location and scope of OST with high sensitivity and specificity, which has important implications for surgical guidance by providing the precise location of OST.

Neuroendocrine tumors (NETs) have reasonably high 5-year survival rates when diagnosed at an early stage but are significantly more lethal when discovered only after metastasis. Although several imaging modalities such as computed tomography (CT), positron emission tomography, and magnetic resonance imaging can detect neuroendocrine tumors, their high false positive rates suggest that more specific diagnostic tests are required. Targeted imaging agents such as Octreoscan® have met some of this need for improved specificity, but their inability to image poorly differentiated NETs suggests that improved NET imaging agents are still needed. Because neurokinin 1 receptors (NK1Rs) are widely over-expressed in neuroendocrine tumors, but show limited expression in healthy tissues, we have undertaken to develop an NK1R-targeted imaging agent for improved diagnosis and staging of neuroendocrine tumors. A small molecule NK1R antagonist was conjugated via a flexible spacer to a Tc-99m chelating peptide. After complexation with Tc-99m, binding of the conjugate to human embryonic kidney (HEK293) cells transfected with the human NK1R was evaluated as a function of radioimaging agent concentration. In vivo imaging of HEK293-NK1R tumor xenografts in mice was also performed by single-photon emission computed tomography/computed tomography (γ-SPECT/CT), and the distribution of the conjugate in various tissues was quantified by tissue resection and γ-counting. NK1R-targeted Tc-99m-based radioimaging agent displayed excellent affinity (Kd = 16.8 nM) and specificity for HEK293-NK1R tumor xenograft. SPECT/CT analysis of tumor-bearing mice demonstrated significant tumor uptake and high tumor to background ratio as early as 2 h post injection. The excellent tumor contrast afforded by our NK1R-targeted radioimaging agent exhibits properties that could improve early diagnosis and staging of many neuroendocrine tumors.

Clinically evident arterial thrombosis is rare following thrombin injection therapy for femoral pseudoaneurysm. However, it is unclear to what extent injected thrombin may pass to the ipsilateral lower limb arteries. To assess if technetium 99m injected at the time of thrombin injection for femoral artery pseudoaneurysm therapy passes into the adjacent lower limb arteries. This was a prospective trial with institutional review board approval. Four consecutive patients with common femoral pseudoaneurysms and failed manual compression were enrolled. Under real-time colour flow doppler ultrasound, a mixture of 1000 IU thrombin and approximately 200 MBq technetium 99m was injected in 0.1-mL doses into the pseudoaneurysm until thrombosis occurred. Gamma camera imaging of the syringe before injection, the injected groin after thrombosis and the syringe after injection were performed. Analysis of the gamma camera information was performed to determine the amount of technetium 99m deposited in the arterial tree. All the procedures were technically successful. A mean of 33% (range 3–50%; SD 21) of the administered technetium 99m dose was deposited in the arterial circulation during pseudoaneurysm therapy. No clinically evident arterial thrombosis was identified. Technetium 99m is routinely deposited in the arterial circulation following injection of a mixture of thrombin and technetium for therapy of common femoral artery pseudoaneurysms. This suggests that arterial passage of thrombin is more common than clinically evident.

Background: Primary hyperparathyroidism is uncommon in equids. Objectives: To describe the diagnostic findings and efficacy of treatment in equids with primary hyperparathyroidism. Study design: Retrospective case series describing 16 horses and one mule. Methods: Cases were identified by retrospective review of records at Cornell University and via an ACVIM listserv query. Inclusion criteria were an equid with hypercalcemia, normal renal function and high parathyroid hormone (PTH) or histopathological diagnosis of a parathyroid adenoma. Equids with normal PTH and PTH-related protein (PTHrP) in the face of hypercalcemia were included as suspect cases. Results: The most common presenting complaints were weight loss (12/17) and hypercalcemia (10/17). PTH was above reference range in 12/17 cases. Suspected parathyroid tumours were localised in 12/14 equids imaged using ultrasonography alone (2/3), technetium 99m Tc sestamibi scintigraphy alone (1/1) or both modalities (9/10). Three horses did not have imaging performed. Surgical exploration successfully excised tumours in six of 10 cases. Five were located at the thoracic inlet, and surgery resulted in complete cure. One tumour was excised from the thyroid lobe, and the horse remained hypercalcemic. Four other cases explored surgically, four treated medically and three that were not treated also remained hypercalcemic. Main limitations: The small study size prohibited statistical analysis. Conclusions: Parathyroid adenomas in equids can be successfully localised with ultrasonography and scintigraphy. Surgical excision appears more likely to be successful for single gland disease at the thoracic inlet.

Aim Breast cancer is a health problem worldwide with high incidence and mortality rates. It is well known that the development of more sensitive and specific diagnostic methods is of great importance since an early diagnosis is essential to successfully treat tumors. Lapachol is a natural compound, belonging to the naphthoquinone group that has been widely used in traditional medicine to treat various illnesses, including cancer. The aim of this study was to evaluate technetium-99m-labeled lapachol as an imaging probe for breast cancer identification. Methods To achieve this purpose, lapachol was labeled with technetium-99m, radiochemical purity and in vitro stability were determined. Blood clearance, in healthy mice, and biodistribution, in 4T1 tumor-bearing mice, were also evaluated. Results Lapachol was successfully labeled with technetium-99m, with high values of radiochemical yield (95.9 ± 3.4%). In vitro stability showed that the radiolabeled complex remained stable for up to 24 h, with values above 90% for both saline and plasma (95.6 ± 3.6% and 96.4 ± 1.7%, respectively). The radiolabeled complex decays in a biphasic manner, with a half-life of distribution and elimination equal to 3.3 and 50.0 min, respectively. Biodistribution and scintigraphic images showed high uptake in organs of excretion (kidneys, liver, and intestine). It could be also noted that tumor uptake was higher than the muscle at all time points. Tumor-to-muscle ratio reaches ∼4.5 at 24 h after administration. Conclusion These findings suggest that 99mTc-Lapachol can be a potential diagnostic agent for breast tumors.

Fibrodysplasia ossificans progressiva is a rare genetic disease believed to occur in approximately 1 in 2 million people worldwide and is characterized by progressive extraosseous ossification over the course of a lifetime in an inevitable and unpredictable episodic manner, with most patients being confined to a wheelchair by the third decade of life and requiring life-long care. The extraosseous calcification involves ligaments, tendons, muscles, and connective tissue leading to severe restriction of movements. Another hallmark of this condition is abnormal great toes. The diagnosis is often made on clinical and radiological examination, but Technetium-99m methylene diphosphonate (Tc-99m MDP) bone scan is usually indicated to determine the extent of the disease. We hereby present a case series comprising of four patients suffering from this debilitating illness who underwent Tc99m MDP bone scan for initial diagnosis and localizing sites of heterotopic ossification.

Spines is a common site of extrapulmonary Mycobacterium tuberculosis infection (MTI). Spine destruction due to MTI can mimic other etiologies. Treatment of choice for spinal tuberculosis (STB) is anti-TB drugs while surgery could be needed in other causes. The gold standard for STB diagnosis is histopathology examination from biopsy tissue. Technetium-99m-ethambutol (99mTc-EMB) scintigraphy can be used to detect and localize of TB. The aim of this study was to evaluate the role of 99mTc-EMB scintigraphy in STB management. Retrospective study was carried out from 2006 to 2014. Subject STB were patient STB with suspected of STB and underwent 99mTc-EMB scintigraphy. The histopathologic result was used as gold standard. Whole body planar acquisition was taken at 1 and 3 h postinjection of 370 MBq. Single-photon emission computed tomography/computed tomography acquisition was performed on suspected area. 99mTc-EMB image were analyzed by two nuclear medicine specialis. The 93 subject STB were included in this study. Histopathologic data were available in 40/93 subject STB. Positive and negative 99mTc-EMB scintigraphy were 32 and 8 subject STB. 99mTc-EMB scintigraphy result STB was concordance with the histopathologic finding in 37 subject STB. Sensitivity, specivicity, positive- and negative-predictive value, and accuracy of 99mTc-EMB scintigraphy 90.91%, 71.43%, 93.75%, 62.5%, and 87.5%, respectively. This study showed that patient STB with suspected 99mTc-EMB scintigraphy result could be directly treated with anti-TB. 99mTc-EMB scintigraphy has significant role in the management of STB.

Objective The aim of this study was to determine whether technetium-99m (99mTc) nanocolloid was a suitable alternative tracer for carrying out milk scan studies in pediatric patients. Participants and methods Twenty-seven milk scans performed with 99mTc nanocolloid were retrospectively assessed for identification of significant esophageal hold-up, gastroesophageal reflux, pulmonary aspiration, and gastric emptying (GE). Scans were also assessed for liver, spleen, and bone marrow uptake. GE results were compared with those of 27 randomly selected normal GE studies carried out using 99mTc tin colloid. Results None of the studies had liver, spleen, or bone marrow uptake, and all studies were interpretable. Significant esophageal hold-up and gastroesophageal reflux was observed in 11 and 48% of the patients, respectively. Only one patient had evidence of pulmonary aspiration, and all patients had normal GE at 2 h after radiolabeled milk ingestion. The average rate of GE at 2 h was faster in the 99mTc nanocolloid group compared with the 99mTc tin colloid group (8.85% retained±8.96% vs. 15.48% retained±10.52%, P=0.016). Conclusion Our findings show that 99mTc nanocolloid is technically a suitable alternative to 99mTc sulfur colloid for performing milk scans. However, we could not conclude with certainty on the comparison of the GE rates of 99mTc nanocolloid and 99mTc tin colloid. This was because of the variability in the two population groups as well as the fact that the milk that was used in each patient was individualized to the patient and was not standardized.

The aim of this observational cross-sectional study with retrospective review of the data is to evaluate the efficacy of using technetium-99m-octreotide (Tc-99m-OCT) in imaging neuroendocrine tumors (NETs) in our tertiary care hospital. A total of 58 patients had Tc-99m-OCT were identified in our database, from January 2013 to December 2016. Forty-one patients (age range of 15–75 years) meet our inclusion criteria, namely histopathology proven NETs, Tc-99m-OCT scan, computed tomography (CT), or magnetic resonance imaging (MRI) done in our institute for correlation. Twenty-three patients had true positive Tc-99m-OCT scan. In addition to the primary tumors, the octreotide scan revealed metastasis in the lung, liver, and retroperitoneal lymph nodes. The smallest lesion detected on octreotide scan was a 4-mm pulmonary nodule that was missed on lung window CT scan. The Tc-99m-OCT had 17 true negative, one false negative, and no false positive. The CT and MRI scans had 18 true positive, 17 true negative, 5 false negative, and one false positive. The overall sensitivity, specificity, accuracy, positive, and negative predictive values of Tc-99m-OCT scan were 96%, 100%, 97%, 100%, and 94%, respectively. Whereas those of CT and MRI were 78%, 94%, 85%, 94%, and 77%, respectively. Our diagnostic accuracy of Tc-99m-OCT is high. We recommend that, in addition to the conventional radiological investigations, Tc-99m-OCT scan, or other somatostatin receptor imaging (SSR) is a mandate for better and accurate staging of patients with NETs.

Background The fluorescent dye indocyanine green (ICG) has emerged as a promising tracer for intraoperative detection of sentinel lymph nodes (SLNs) in early‐stage cervical cancer. Although researchers suggest the SLN detection of ICG is equal to the more conventional combined approach of a radiotracer and blue dye, no consensus has been reached. Aims We aimed to assess the differences in overall and bilateral SLN detection rates with ICG versus the combined approach, the radiotracer technetium‐99m (99mTc) with blue dye. Methods and Results We searched MEDLINE, Embase, and the Cochrane Library from inception to January 1, 2020 and included studies reporting on a comparison of SLN detection with ICG versus 99mTc with blue dye in early‐stage cervical cancer. The overall and bilateral detection rates were pooled with random‐effects meta‐analyses. From 118 studies retrieved seven studies (one cross‐sectional; six retrospective cohorts) were included, encompassing 589 patients. No significant differences were found in the pooled overall SLN detection rate of ICG versus 99mTc with blue dye. Meta‐analyses of all studies showed ICG to result in a higher bilateral SLN detection rate than 99mTc with blue dye; 90.3% (95%CI, 79.8‐100.0%) with ICG versus 73.5% (95%CI, 66.4‐80.6%) with 99mTc with blue dye. This resulted in a significant and clinically relevant risk difference of 16.6% (95%CI, 5.3‐28.0%). With sensitivity analysis, the risk difference of the bilateral detection rate maintained in favor of ICG but was no longer significant (13.2%, 95%CI −0.8‐27.3%). Conclusion ICG appears to provide higher bilateral SLN detection rates compared to 99mTc with blue dye in patients with early‐stage cervical cancer. However, in adherence with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidelines, the quality of evidence is too low to provide strong recommendations and directly omit the combined approach of 99mTc with blue dye.

To develop potential technetium-99m single-photon emission computed tomography (SPECT) imaging agents for bacterial infection imaging, the novel norfloxacin isonitrile derivatives CN4NF and CN5NF were synthesized and radiolabeled with a [99mTc][Tc(I)]+ core to obtain [99mTc]Tc-CN4NF and [99mTc]Tc-CN5NF. These compounds were produced in high radiolabeling yields and showed hydrophilicity and good stability in vitro. The bacterial binding assay indicated that [99mTc]Tc-CN4NF and [99mTc]Tc-CN5NF were specific to bacteria. Compared with [99mTc]Tc-CN4NF, biodistribution studies of [99mTc]Tc-CN5NF showed a higher uptake in bacteria-infected tissues than in turpentine-induced abscesses, indicating that [99mTc]Tc-CN5NF could distinguish bacterial infection from sterile inflammation. In addition, [99mTc]Tc-CN5NF had higher abscess/blood and abscess/muscle ratios. SPECT image of [99mTc]Tc-CN5NF showed that there was a clear accumulation in the infection site, suggesting that it could be a potential bacterial infection imaging radiotracer.

Goiter with an intrathoracic component is relatively common; however, it is less common to see extent outside the anterior or posterior mediastinum. We present a case of intrathoracic goiter of significant size and abnormal placement which is examined using both 99mTc-pertechnetate and iodine-123 single-photon emission computed tomography/computed tomography.

BackgroundThis study aimed to evaluate the clinical value of indocyanine green sentinel lymph node (SLN) mapping in patients with vulvar cancer. The conventional procedure of SLN mapping in vulvar cancer includes peritumoral injection of technetium-99m nanocolloid before surgery and intraoperative injection of a blue dye. However, these techniques harbor some limitations. Near-infrared fluorescence imaging with indocyanine green has gained popularity in SLN mapping in different types of cancer.MethodsWe analyzed retrospectively vulvar cancer patients at our institution between 2013 and 2020 undergoing indocyanine green SLN mapping by applying video telescope operating microscope system technology.Results64 groins of 34 patients were analyzed. In 53 groins we used technetium-99m nanocolloid, in four patent blue, and in five both techniques, additionally to indocyanine green for SLN detection. In total, 120 SLNs were identified and removed. The SLN detection rate of indocyanine green was comparable to technetium-99m nanocolloid (p=.143) and higher than patent blue (p=.003). The best results were achieved using a combination of ICG and technetium-99m nanocolloid (detection rate of 96.9%). SLN detection rates of indocyanine green were significantly higher in patients with positive lymph nodes (p=.035) and lymphatic space invasion (p=.004) compared to technetium-99m nanocolloid.ConclusionIndocyanine green SLN mapping in vulvar cancer is feasible and safe, with reasonable detection rates. Due to its easy application and few side effects, it offers a sound alternative to the conventional SLN mapping techniques in vulvar cancer. In patients with lymph node metastasis, indocyanine green even outperformed technetium-99m nanocolloid in terms of detection rate.

Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Russian Science Foundation BACKGROUND To date, radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) is a valuable treatment option. So far there are no clear predictors of the effectiveness of AF ablation. Nowadays, the association of cardiac sympathetic nervous system and the development and maintenance of AF has been showed. The association between сardiac sympathetic system impairment, assessed by 123I-MIBG scintigraphy and RFCA effectiveness was shown previously. However, the is lack of data concerning to prognostic value of MIBG scintigraphy in patients with different forms of AF – persistent (PAF) and long-standing persistent (LSPAF). PURPOSE To study the prognostic significance of 123I-MIBG scintigraphy in RFCA efficacy in patients with persistent and long-standing persistent AF. METHODS The study enrolled 36 patients with drug-resistant AF (both persistent (n = 20) and long-standing persistent (n = 16) forms). All patients had comorbidity as chronic coronary syndrome and hypertension. A comparison group (n = 10) was also enrolled in the study. It includes patients with chronic coronary syndrome and arterial hypertension (without arrhythmia). All patients underwent 123I-MIBG and 99mTc-MIBI scintigraphy to evaluate the cardiac sympathetic activity and myocardial perfusion, respectively. Patients with AF performed RFCA. After of 1 year follow-up patients were examined for AF recurrence. The AF recurrence was considered to be an AF of at least 30 sec duration on a 12-lead ECG or on the Holter monitoring. RESULTS During the follow-up period, AF recurrences were reported in 7 (35%) PAF patients and in 8 (50%) LSPAF patients. According to multivariate analysis only a high pre-ablation washout rate of 123I-MIBG (WR) in PAF patients (OR: 1.668; 95% CI: 1.093–2.548) and large pre-ablation 123I-MIBG/99mTc-MIBI mismatch score in LSPAF patients (OR: 2.155; 95% CI: 1.192–3.897) were independent predictors of AF recurrence after RFCA. ROC analysis indicated that in PAF patients with higher WR ≥ 20.8% (AUC: 0.968; Sensitivity: 100 %; Specificity: 45%; p < 0.05) and LSPAF patients with larger 123I-MIBG/99mTc-MIBI mismatch score ≥ 12.5 % (AUC: 0.942; Sensitivity: 81 %; Specificity: 28 %; p < 0.05) had a higher risk of AF recurrence after RFCA. CONCLUSION In AF patients the incidence of arrhythmia recurrence after RFCA is associated with impaired cardiac sympathetic nervous activity. In PAF patients the values of 123I-MIBG washout rate can predict AF recurrence. In LSPAF patients innervation/perfusion mismatch has prognostic value in terms of AF recurrence.

Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Background Myocardial extracellular volume (ECV) increases with fibrosis, oedema or infiltration. ECV by CMR predicts all-cause and cardiovascular mortality in severe AS after valve intervention. Previous studies have shown that ECV can be reliably quantified by computed tomography (ECVCT), but these studies have not differentiated between ECV elevation due to fibrosis or cardiac amyloid deposition (13-16% of patients with severe AS). Purpose We hypothesised that ECVCT quantification, performed as part of a transcatheter aortic valve implantation (TAVI) work-up CT, predicts survival in patients with severe AS without cardiac amyloid (lone AS). Methods Patients aged ≥75, with severe AS, referred for TAVI at Barts Heart Centre (as part of ATTRact-AS (NCT03029026)) underwent CT as part of their clinical work-up. All patients had 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy and those with a positive result were excluded. CT was performed on a 128-slice dual-source 3rdgeneration scanner (Siemens Somatom FORCE) and ECVCT was acquired during the TAVI work-up CT using additional pre- and 3-minute post-contrast ‘axial shuttle mode’ acquisitions (no additional contrast). ECVCT was calculated from the Hounsfield units (HU) and a venous haematocrit (HCT): ECVCT = (1-HCT) x (ΔHUmyo/ΔHUblood). Results Following exclusion of 16 patients with cardiac uptake on DPD, 93 patients (41% male, aged 85 ± 5 years) were included in the study. All patients had severe AS (AV Vmax 4.12 ± 0.63m/s, mean AV gradient 42 ± 14mmHg, AVA 0.71 ± 0.23cm2). The mean HCT was 0.38 ± 0.04 and total dose-length product for additional research scans was 364 ± 41 mGy.cm. 76 patients (82%) underwent TAVI. ECVCT was 32 ± 3% in the entire cohort, which we then split into those with a ‘higher’ ECVCT (>34%, n = 23, representing the highest quartile) and those with a ‘lower’ ECVCT (≤34%, n = 70, representing the lower quartiles). Over a median follow-up of 25 months (IQR 17-34 months) there were 27 deaths (29%), of whom 11 did not undergo TAVI (41%). There were 10 deaths in the 23 patients (44%) with a higher ECVCT, compared to 17 in the 70 patients (24%) with a lower ECVCT (p = 0.03, figure 1). This mortality difference remained significant when those patients who did not undergo TAVI were excluded (p = 0.03). Conclusions Myocardial fibrosis quantified by ECVCT is associated with a significantly worse prognosis in lone AS, even after patients with AS-amyloid are excluded. ECVCT can be performed as a simple addition to the TAVI work-up CT and provides additional prognostic information. Abstract Figure.

Background: Infective endocarditis (IE) is an infection of the heart’s endocardial surface. In recent years, nuclear imaging methods have gained importance in the diagnosis of IE. The present study aims to investigate the imaging potential of 99mTc-labeled vancomycin (99mTc-Vancomycin) as a new agent that would enable the diagnosis of IE in its early stages when it is difficult to diagnose or has small vegetation in the experimental rat model. Methods: 99mTc-Vancomycin scintigraphy was evaluated for its accumulation in IE with Staphylococcus aureus performed in an experimental rat model. Serial planar scintigraphic and biodistribution analysis of infected vegetations are compared to rats with sterile vegetations. The heart was identified as an infected organ, the liver was identified as a non-infected organ and the heart/liver uptake ratio (T / NT ratio) was compared between infective endocarditis and sterile endocarditis groups. Results: Planar scintigrams (in vivo measurements) showed more uptake in the heart of rats in the infective endocarditis group compared to the uptake in the heart of rats in the sterile endocarditis group, but this difference was not statistically significant (p>0.05). From the ex vivo measurements, the 99mTc-Vancomycin heart uptake increased significantly (p = 0.016), liver uptake was significantly decreased (p = 0.045) and the T/NT ratio was significantly higher (p = 0.014) in the infective endocarditis group compared to the sterile endocarditis group. Conclusions: In this experimental study, 99mTc-Vancomycin scintigraphy ensured the detection of ex vivo infected tissue in a rat model of IE. In addition, the absence of significant 99mTc-Vancomycin uptake in the sterile endocarditis group indicates that this agent targeted the infected tissue instead of the sterile inflammatory tissue. Finally, this agent should also be evaluated with animal- specific imaging devices.

For effective Auger therapy of cancer, the Auger-electron emitters must be delivered to the tumor cells in close proximity to a radiosensitive cellular target. Nuclear DNA is considered the most relevant target of Auger electrons to have augmented radiotoxic effects and significant cell death. However, there is a growing body of evidence that other targets, such as the mitochondria, could be relevant subcellular targets in Auger therapy. Thus, we developed dual-targeted 99mTc(I) tricarbonyl complexes containing a triphenylphosphonium (TPP) moiety to promote accumulation of 99mTc in the mitochondria, and a bombesin peptide to provide specificity towards the gastrin releasing peptide receptor (GRPr) overexpressed in prostate cancer cells. The designed dual-targeted complex, 99mTc-TPP-BBN, is efficiently internalized by human prostate cancer PC3 cells through a specific GRPr-mediated mechanism of uptake. Moreover, the radioconjugate provided an augmented accumulation of 99mTc in the mitochondria of the target tumor cells, most probably following its intracellular cleavage by cathepsin B. In addition, 99mTc-TPP-BBN showed an enhanced ability to reduce the survival of PC3 cells, in a dose-dependent manner.

5-Fluorouracil (5-FU) is an antineoplastic drug that causes, as a side effect, intestinal mucositis, acute inflammation in the small bowel. The Heat Shock Protein (Hsp) are highly expressed in inflammatory conditions, developing an important role in immune modulation. Thus, they are potential candidates for the treatment of inflammatory diseases. In the mucositis mouse model, the present study aimed to evaluate the beneficial effect of oral administration of milk fermented by Lactobacillus delbrueckii CIDCA 133 (pExu:hsp65), a recombinant strain. This approach showed increased levels of sIgA in the intestinal fluid, reducing inflammatory infiltrate and intestinal permeability. Additionally, the histological score was improved. Protection was associated with a reduction in the gene expression of pro-inflammatory cytokines such as Tnf, Il6, Il12, and Il1b, and an increase in Il10, Muc2, and claudin 1 (Cldn1) and 2 (Cldn2) gene expression in ileum tissue. These findings are corroborated with the increased number of goblet cells, the electronic microscopy images, and the reduction of intestinal permeability. The administration of milk fermented by this recombinant probiotic strain was also able to reverse the high levels of gene expression of Tlrs caused by the 5-FU. Thus, the rCIDCA 133:Hsp65 strain was revealed to be a promising preventive strategy for small bowel inflammation.

Radiopharmaceuticals have been developed to image selectively most of the organ systems of the body. Most commonly, these agents are labelled with the gamma-emitters technetium-99m, iodine-123 or indium-111. The most widely used studies are skeletal scintigraphy, myocardial perfusion imaging, and lung ventilation and perfusion imaging; the targeting agents used are, respectively, bisphosphonate compounds that bind to the hydroxyapatite matrix, lipophilic cations that are trapped in the mitochondria of myocytes, aerosols that outline the airways and particles that are trapped in pulmonary capillaries. If targeting is sufficiently high, the same or similar agents can be labelled with beta- or alpha-particle-emitting radionuclides for therapy. The most common radionuclide therapy is iodine-131 sodium iodide for benign or malignant thyroid disease. After many years of promise, there has been a great expansion in the use of radionuclide therapy with the recent introduction of lutetium-177 somatostatin-receptor-binding peptides (e.g. DOTATATE) for the treatment of neuroendocrine tumours and radium-223 chloride for use in metastatic prostate cancer.

Imaging in patients with Paget's disease of bone is very important clinically to show the presence of Pagetic abnormalities, assess disease progression, and identify adversely affected structures throughout disease course. Abnormalities and progression may be seen on radiographs, computed tomography, magnetic resonance imaging, and nuclear imaging. Herein, we report a case Paget's disease of bone showing diffuse characteristic pathology using technetium-99m-labelled diphosphonate tracer in bone scintigraphy (nuclear imaging). This case emphasizes the ability of nuclear imaging to rapidly visualize and assess progressive distribution of Pagetic involvement in a patient previously diagnosed with pituitary adenoma and mild Paget's disease of the skull.

Background Cardiac amyloidosis (CA), characterized by amyloid protein deposition in the heart, is a treatable disease. Although left ventricular (LV) wall thickness is the most established imaging predictor for CA, several echocardiographic indices including deformation parameters also contribute to the screening of CA. However, it is unclear whether additive values of echocardiographic indices have greater benefit over the conventional clinical predictors for the screening of CA. Therefore, we sought to compare the incremental benefits of echocardiographic indices over the clinical parameters for the screening of CA and externally validate their incremental benefits. Methods We retrospectively studied 295 consecutive patients (median age, 67 years; male, 65%; mean LV wall thickness (MWT), 12 mm) with LV hypertrophy who underwent echocardiography as well as the detailed work-up for myocardium (Biopsy, technetium pyrophosphate scintigraphy (99mTc-PYP) or cardiac magnetic resonance imaging). CA was diagnosed through biopsy or 99mTc-PYP. The clinical model considers patients' age and the low-voltage in electrocardiography in reference to previous studies. Continuous echocardiographic variables were represented in binary through generally accepted external cutoff points. The incremental benefits of the echocardiography findings over the clinical model were assessed using with the help of both receiver-operated characteristic curve analysis and comparison of area under the curves. Furthermore, these incremental benefits were validated in the external validation sample (median age, 70 years; male, 69%; MWT, 12 mm). Results Among the enrolled patients, CA was observed in 18% of cases. Table presents the results of this study. Of the echocardiographic parameters, relative apical sparing pattern (RASP) was the greatest contributor for improvement of diagnostic accuracy of the clinical model. The next greatest contributor was LV wall thickness, followed by left atrial reservoir strain (LAS), E/e', left atrial volume index, ejection fraction strain ratio, and pericardial effusion, respectively. Similarly, RASP, LV wall thickness, global longitudinal strain, ejection fraction, LAS, and granular sparkling showed significant incremental benefit in the validation cohort. Only mean wall thickness, LV wall thickness, LAS, E/e' and RASP consistently improved the diagnostic accuracy of the clinical model. Conclusion During the screening process, adding LV wall thickness, LAS, and RASP to the clinical parameters may be useful for the accurate diagnosis of CA in patients with LV hypertrophy. Figure 1 Funding Acknowledgement Type of funding source: None

Background/Introduction Recent recognition that ATTR cardiac amyloidosis (ATTR-CA) is not uncommon and the emergence of novel therapeutic opportunities resulted in the publication of “Expert Consensus Recommendations for Multimodality Imaging in Cardiac Amyloidosis”. However, almost all data were derived from general purpose NaI cameras, while new cardiac dedicated CZT cameras are becoming more widespread. Purpose To evaluate Tc-99m pyrophosphate (PYP) scintigraphy on D-SPECT cardio dedicated CZT camera (Spectrum Dynamics) in suspected ATTR-CA patients. Methods Seventy three consecutive patients suspected for ATTR-CA underwent planar (5 min), SPECT and gated SPECT (10 min, 8 bins) scintigraphy 89±26 min after injection of Tc99m-PYP 740 MBq, followed by late scintigraphy after 92±36 min in 65 consecutive patients. Perguini visual score, planar H/CL and SPECT derived H/CL ratio were evaluated by two blinded independent experienced readers. Diagnosis was based on visual interpretation after blood pool and monoclonal gammopathy were excluded. Results Very good to excellent planar and SPECT image quality was observed in almost all patients. PYP scintigraphy was positive in 6/73 patients, with left ventricular wall uptake clearly evident in the planar images of most patients. There was perfect agreement between readers regarding positive/negative interpretation. There was also substantial inter-observer agreement regarding the Perguini scoring (Cohen's k with linear weighting 0.819, 95% CI 0.701–0.937). Inter-observer agreement for H/CL ratio was also good (Pearson's correlation coefficient r(71)=0.873). SPECT and gated SPECT images were helpful only in one positive patient, and did not have an added value in any of the negative studies. Slightly better images were observed during late scintigraphy, but there was no change in interpretation, and H/CL ratio was not significantly changed (median difference −0.01, IQR 0.09). Alas, Inter-observer agreement of H/CL ratio was lower (Pearson's correlation coefficient r(64)=0.633). We also evaluated H/CL ratio derived from SPECT based application of the camera manufacturer. Agreement between early planar and early SPECT based H/CL ratio was good for both readers (r(69)=0.778 and r(66)=0.747), but inter-observer agreement was lower (r(66)=0.697). Conclusions ATTR PYP scintigraphy using cardiac dedicated CZT camera yielded excellent images in almost all patients, and uptake in the left ventricular wall could be easily identified in positive patients. Inter-observer agreement was excellent for both visual scoring and planar H/CL ratio. Early planar images were high quality, and limited additional diagnostic value was observed for both SPECT and gated SPECT scintigraphy and from later acquisition. Funding Acknowledgement Type of funding source: None

Introduction Indocyanine green (ICG) is a promising tracer in sentinel lymph node (SLN) procedure in patients with early stage cervical cancer. Our objective was to assess the differences in overall and bilateral detection rates of ICG versus technetium-99 m (99mTc) with or without blue dye. Methods We searched Medline, Embase and the Cochrane Library from inception to April 1st, 2020. Studies reporting on a direct comparison of SLN detection with ICG versus 99mTc ± blue dye in early stage cervical cancer were included. Two reviewers independently selected eligible articles and assessed study quality using the ROBINS-I tool. The overall and bilateral detection rates were pooled with random-effects meta-analyses. Results From 112 studies retrieved, nine met selection criteria. One study was excluded due to a critical risk of bias. The remaining eight cohort studies of limited quality (two prospective; six retrospective) included 654 patients. No significant differences were found in the pooled overall detection rate of ICG versus 99mTc ± blue dye (98.7% (95%CI, 96.5–100.0%) versus 95.6% (95%CI, 92.1–99.2%), respectively). Use of ICG significantly increased bilateral detection rates compared with 99mTc ± blue dye; 91.5% (95%CI, 82.3–100%) versus 71.7 (95%CI, 64.7–78.7%), respectively, with an OR of 5.17 (95% CI, 1.88–14.21, P 0.01). Five studies reported on patients in partial overlap of each other. No adverse events related to ICG were described. Conclusion/Implications In early stage cervical cancer, ICG appears to be superior to the 99mTc with or without blue dye in terms of bilateral SLN detection. Additional prospective studies are needed.