How anatomical impairments found on CT affect perfusion percentage assessed by SPECT/CT scan?

AIM: CT images can identify structural and opacity alterations of the lungs while nuclear medicine's lung perfusion studies show the homogeneity (or lack of) of blood perfusion on the organ. Therefore, the use of SPECT/CT in lung perfusion scintigraphies can help physicians to assess anatomical and functional alterations of the lungs and to differentiate between acute and chronic disease. OBJECTIVE: To develop a computer-aided methodology to quantify the total global perfusion of the lungs via SPECT/CT images and to compare these results with parenchymal alterations obtained in CT images. METHODS: 39 perfusion SPECT/CT images collected retrospectively from the Nuclear Medicine Facility of Botucatu Medical School's Clinics Hospital in São Paulo, Brazil, were analyzed. Anatomical lung impairments (emphysema, collapsed and infiltrated tissue) and the functional percentage of the lungs (blood perfusion) were quantified from CT and SPECT images, with the aid of the free, open-source software 3D Slicer. The results obtained with 3D Slicer (3D-TGP) were also compared to the total global perfusion of each patient's found on their medical report, obtained from visual inspection of planar images (2D-TGP). RESULTS: This research developed a novel and practical methodology for obtaining lungs' total global perfusion from SPECT/CT images in a semiautomatic manner. 3D-TGP versus 2D-TGP showed a bias of 7% with a variation up to 67% between the two methods. Perfusion percentage showed a weak positive correlation with infiltration (p = 0.0070 and ρ = 0.43) and collapsed parenchyma (p = 0.040 and ρ = 0.33). CONCLUSIONS: This research brings meaningful contributions to the scientific community because it used a free open-source software to quantify the lungs blood perfusion via SPECT/CT images and pointed that the relationship between parenchyma alterations and the organ's perfusion capability might not be so direct, given compensatory mechanisms.

Uso de la tomografía corporal total en pacientes con heridas de arma de fuego y hemodinámicamente inestables: ¿Rompiendo paradigmas de atención inicial? / Whole-body computed tomography in hemodynamically unstable patients with gunshot wounds: A paradigm shift in trauma management?

Introducción. El objetivo del estudio fue analizar el impacto del uso de la tomografía corporal total en la evaluación de los pacientes con trauma penetrante por proyectil de arma de fuego y hemodinámicamente inestables atendidos en un centro de referencia de trauma. Métodos. Se realizó un estudio analítico, retrospectivo, con base en un subanálisis del registro de la Sociedad Panamericana de Trauma ­ Fundación Valle del Lili. Se incluyeron los pacientes con trauma penetrante por proyectil de arma de fuego atendidos entre 2018 y 2021. Se excluyeron los pacientes con trauma craneoencefálico severo, trauma leve y en condición in extremis. Resultados. Doscientos pacientes cumplieron los criterios de elegibilidad, 115 fueron estudiados con tomografía corporal total y se compararon con 85 controles. La mortalidad intrahospitalaria en el grupo de tomografía fue de 4/115 (3,5 %) vs 10/85 (12 %) en el grupo control. En el análisis multivariado se identificó que la tomografía no tenía asociación significativa con la mortalidad (aOR=0,46; IC95% 0,10-1,94). El grupo de tomografía tuvo una reducción relativa del 39 % en la frecuencia de cirugías mayores, con un efecto asociado en la disminución de la necesidad de cirugía (aOR=0,47; IC95% 0,22-0,98). Conclusiones. La tomografía corporal total fue empleada en el abordaje inicial de los pacientes con trauma penetrante por proyectil de arma de fuego y hemodinámicamente inestables. Su uso no se asoció con una mayor mortalidad, pero sí con una menor frecuencia de cirugías mayores.

Introduction. This study aims to assess the impact of whole-body computed tomography (WBCT) in the evaluation of patients with penetrating gunshot wounds (GSW) who are hemodynamically unstable and treated at a trauma referral center. Methods. An analytical, retrospective study was conducted based on a subanalysis of the Panamerican Trauma Society-FVL registry. Patients with GSW treated between 2018 and 2021 were included. Patients with severe cranioencephalic trauma, minor trauma, and those in extremis were excluded. Patients with and without WBCT were compared. The primary outcome was in-hospital mortality, and the secondary outcome was the frequency of major surgeries (thoracotomy, sternotomy, cervicotomy, and/or laparotomy) during initial care. Results. Two hundred eligible patients were included, with 115 undergoing WBCT and compared to 85 controls. In-hospital mortality in the WBCT group was 4/115 (3.5%) compared to 10/85 (12%) in the control group. Multivariate analysis showed that WBCT was not significantly associated to mortality (aOR: 0.46; 95% CI 0.10-1.94). The WBCT group had a relative reduction of 39% in the frequency of major surgeries, with an associated effect on reducing the need for surgery (aOR: 0.47; 95% CI 0.22-0.98). Conclusions. Whole-body computed tomography was employed in the initial management of patients with penetrating firearm projectile injuries and hemodynamic instability. The use of WBCT was not associated with mortality but rather with a reduction in the frequency of major surgery.

SPECT/CT con 99mTc-pirofosfato en la evaluación de la amiloidosis cardíaca: estudio preliminar / SPECT/CT with 99mTc-pyrophosphate in the evaluation of cardiac amyloidosis: a preliminary study / SPECT/CT com pirofosfato de 99mTc na avaliação de amiloidose cardíaca: estudo preliminar

Introducción: la amiloidosis cardíaca (AC) es una miocardiopatía infiltrativa producida por depósito miocárdico extracelular de amiloide. Las variantes más frecuentes son debidas a cadenas ligeras de inmunoglobulinas o transtiretina (ATTR). El centellograma con 99mTc-pirofosfato (99mTc-PYP) es una técnica de imagen molecular que permite diferenciar los subtipos más frecuentes de AC. El presente estudio analizó el rol del 99mTc-PYP y el SPECT-CT en la evaluación de pacientes con sospecha clínica de AC. Materiales y métodos: se realizó 99mTc-PYP y SPECT-CT en 16 pacientes con sospecha clínica de AC, con edad promedio de 63 años. Se realizó análisis cualitativo de las imágenes planares y del SPECT-CT (Mediso, AnyScan), adquiridas 1-3 horas tras la inyección del radiotrazador. Para el análisis cuantitativo de las imágenes planares se calculó la relación H/CL (cuentas promedio obtenidas sobre las regiones de interés del corazón y el hemitórax contralateral). El estudio se consideró positivo para ATTR cuando la relación H/CL fue ≥1.5. Las imágenes de SPECT-CT fueron interpretadas para observar la distribución del trazador a nivel cardíaco y extracardíaco. Resultados: se identificó captación miocárdica de 99mTc-PYP en el ventrículo izquierdo en 6 pacientes y en el ventrículo derecho en 3 pacientes. En estos casos, la relación H/CL fue >1.5. En el resto se descartó la captación miocárdica, con relación H/CL<1.5. Se detectó actividad de pool vascular en las imágenes tomográficas de 7 pacientes y captación extracardíaca ósea anormal de causas traumáticas/degenerativas en 9 pacientes. Cinco pacientes presentaron captación hepática difusa, sin alteración estructural en el TC. Conclusiones: el 99mTc-PYP es una técnica clínicamente relevante en pacientes con sospecha de AC. Constituye una herramienta mínimamente invasiva, ampliamente disponible, de bajo costo y útil en el diagnóstico, pudiendo orientar al subtipo de AC. La información que aporta permite además orientar las opciones terapéuticas y brindar información pronóstica adicional.

Introduction: Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy caused by extracellular myocardial amyloid deposition. The most frequent variants are due to immunoglobulin light chains or transthyretin (ATTR). 99mTc-pyrophosphate (99mTc-PYP) scintigraphy is a molecular imaging technique that allows differentiation of the most common subtypes of AC. The present study analyzed the role of 99mTc-PYP and SPECT-CT in the evaluation of patients with clinical suspicion of CA. Materials and methods: 99mTc-PYP and SPECT-CT were performed in 16 patients with clinical suspicion of AC, with an average age of 63 years. Qualitative analysis was performed on the planar and SPECT-CT images (Mediso, AnyScan), acquired 1-3 hours after the injection of the radiotracer. For the quantitative analysis of the planar images, the H/CL ratio (average counts obtained over the regions of interest of the heart and the contralateral hemithorax) was calculated. The study was considered positive for ATTR when the H/CL ratio was ≥1.5. The SPECT-CT images were interpreted to observe the distribution of the tracer at the cardiac and extracardiac level. Results: Myocardial uptake of 99mTc-PYP was identified in the left ventricle in 6 patients and in the right ventricle in 3 patients. In these cases, the H/CL ratio was >1.5. In the rest, myocardial uptake was ruled out, with a H/CL ratio of 1.5. Vascular pool activity was detected in the tomographic images of 7 patients and abnormal extracardiac bone uptake of traumatic/degenerative causes in 9 patients. Five patients presented diffuse hepatic uptake, without structural alteration on CT. Conclusions: 99mTc-PYP is a clinically relevant technique in patients with suspected CA. It constitutes a minimally invasive tool, widely available, low cost and useful in diagnosis, and can guide the AC subtype. The information it provides also makes it possible to guide therapeutic options and provide additional prognostic information.

Introdução: a amiloidose cardíaca (AC) é uma cardiomiopatia infiltrativa causada pela deposição extracelular de amiloide no miocárdio. As variantes mais frequentes são devidas a cadeias leves de imunoglobulina ou transtirretina (ATTR). A cintilografia com 99mTc-pirofosfato (99mTc-PYP) é uma técnica de imagem molecular que permite a diferenciação dos subtipos mais comuns de QA. O presente estudo analisou o papel do 99mTc-PYP e do SPECT-CT na avaliação de pacientes com suspeita clínica de AC. Materiais e métodos: foram realizados 99mTc-PYP e SPECT-CT em 16 pacientes com suspeita clínica de QA, com idade média de 63 anos. A análise qualitativa foi realizada nas imagens planas e SPECT-CT (Mediso, AnyScan), adquiridas 1-3 horas após a injeção do radiotraçador. Para a análise quantitativa das imagens planas, foi calculada a relação H/CL (contagens médias obtidas nas regiões de interesse do coração e do hemitórax contralateral). O estudo foi considerado positivo para ATTR quando a relação H/CL era ≥1,5. As imagens SPECT-CT foram interpretadas para observar a distribuição do traçador em nível cardíaco e extracardíaco. Resultados: a captação miocárdica de 99mTc-PYP foi identificada no ventrículo esquerdo em 6 pacientes e no ventrículo direito em 3 pacientes. Nestes casos, a relação H/CL foi >1,5. Nos demais, foi descartada captação miocárdica, com relação H/CL de 1,5. Atividade do pool vascular foi detectada nas imagens tomográficas de 7 pacientes e captação óssea extracardíaca anormal de causas traumáticas/degenerativas em 9 pacientes. Cinco pacientes apresentaram captação hepática difusa, sem alteração estrutural na TC. Conclusões: o 99mTc-PYP é uma técnica clinicamente relevante em pacientes com suspeita de AC. Constitui uma ferramenta minimamente invasiva, amplamente disponível, de baixo custo e útil no diagnóstico, podendo orientar o subtipo AC. A informação que disponibiliza permite também orientar opções terapêuticas e fornecer informação prognóstica adicional.

Solitary Neuroblastoma in the Scapula.

ABSTRACT: Majority of primary pediatric neuroblastomas occur in the abdomen, followed by posterior mediastinum. A 7-year-old girl presented worsening pain in the left shoulder, and a CT image of the chest revealed osseous destruction in the left scapula, suggestive of bone tumor. A biopsy was performed. Pathological result was consistent with neuroblastoma. A 123I scan with SPECT/CT images was performed, which showed only increased activity in the left scapula without any other foci of abnormal activity elsewhere.

The role of SPECT/CT in painful, noninfected knees after knee arthroplasty: a systematic review and meta-analysis-a diagnostic test accuracy review.

PURPOSE: The aim of this systematic review was to present the current evidence on the clinical use of single-photon emission computed tomography/computed tomography (SPECT/CT) in the evaluation of noninfected painful knees after knee arthroplasty. METHODS: Embase, PubMed, Google Scholar, Ovid, Scopus, Science Direct and the Cochrane Database of Systematic Reviews were searched from database inception to May 2022 following the PRISMA guidelines. As a primary outcome, we defined the role of SPECT/CT in the diagnostic approach to noninfected painful knee arthroplasty; as a secondary objective, we described the noninfection-related factors linked to painful knee arthroplasty. Pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio values and other indicators were calculated; receiver operating characteristic (ROC) curve analysis results and a summary of the areas under the curve (AUCs) from the included studies were reported. A Fagan plot, likelihood ratio plot and Deeks' funnel plot were generated and analysed. Methodological quality was assessed using the QUADAS-2 tool, and the certainty of evidence was assessed by the GRADE approach. RESULTS: A total of 493 publications were identified, of which eight met the inclusion criteria, with a final pooled sample size of 308 patients. The pooled sensitivity and specificity of SPECT/CT in diagnosing the source of pain in painful knee prostheses were 0.86 (95% CI: 0.75-0.93) and 0.90 (95% CI: 0.79-0.96), respectively, with pooled +LR and -LR values of 8.9 (95% CI: 4.11-19.19) and 0.15 (95% CI: 0.09-0.28). The pooled diagnostic odds ratio was 57.35, and the area under the curve was 0.94. SPECT/CT highly accurately identified different sources of pain, such as loosening of the prosthetic components, patellofemoral overloading, instability, malalignment of the components and degeneration of the patellofemoral compartment. The confidence of the estimates was moderate according to the GRADE approach. CONCLUSION: With demonstrated high sensitivity and specificity, as a diagnostic tool, SPECT/CT can identify the source of pain in painful knees after knee arthroplasty, particularly in cases of loosening, patellofemoral disorders and component malalignment (level of evidence III). These findings have significant clinical repercussions, such as in changing the initial diagnosis, identifying or excluding different causes of painful knee arthroplasties, guiding subsequent treatment and positively impacting the final clinical outcome. We moderately recommend the use of SPECT/CT for identifying the source of pain after knee arthroplasty according to the GRADE assessment. This review was preregistered in Prospero under code CRD42022320457.

Incidental Diagnosis of Metastatic Breast Cancer in a Man With 99m Tc-PSMA SPECT/CT.

ABSTRACT: Breast cancer in men is a rare and unsuspected malignancy. A 48-year-old man begins with disabling low back pain. The CT scan reported a compression fracture in L2 and diffuse skeletal lesions suggestive of metastatic disease. The serum prostate-specific antigen was 6.2 ng/mL. He was referred for SPECT/CT with 99m Tc-EDDA/HYNIC-inhibitor prostate-specific membrane antigen due to clinical suspicion of prostate cancer. SPECT/CT with 99m Tc-EDDA/HYNIC-inhibitor prostate-specific membrane antigen showed a primary lesion in the left breast and multiple bone lesions. Biopsy confirmed infiltrating ductal carcinoma with positive hormone receptors and indeterminate HER2 (human epidermal growth factor receptor 2).

Dosis efectivas asociadas a estudios híbridos SPECT-CT en pacientes adultos / Effective dose associated to hybrid SPECT-CT imaging in adult patients / Doses eficazes associadas a estudos de SPECT-CT híbridos em pacientes adultos

Introducción: la técnica de imagen híbrida de SPECT-CT combina la imagen de la tomografía por emisión de fotón único (SPECT) con el estudio de tomografía computada (TC), obteniendo información funcional y anatómica en un mismo estudio. La dosis efectiva total de radiación ionizante recibida en los estudios SPECT-CT puede ser estimada a partir de la dosis efectiva atribuible a la actividad administrada del radiofármaco y la dosis efectiva del componente de tomografía computada (TC). Objetivos: estimar la dosis efectiva total en los protocolos SPECT-CT utilizados en población adulta y determinar el aporte adicional del estudio TC sobre la dosis efectiva total. Método: se evaluaron 258 estudios SPECT-CT para estimar la dosis efectiva total aportada por la administración de los radiofármacos y los estudios de TC de baja dosis. Para estimar el aporte de ambos componentes se utilizaron factores de conversión específicos de cada radiofármaco y región explorada mediante TC. Resultados: la dosis efectiva total (media ± DS) en los estudios SPECT-CT fueron: 12,4 ± 1,44 mSv en el estudio de perfusión miocárdica, 1,14 ± 0,25 mSv en ganglio centinela de mama, 8,6 ± 0,6 mSv paratiroides, 1,48 ± 1,02 mSv tiroides y los estudios óseos de las regiones de cuello 4,5 ± 0,3, tórax 6,07 ± 0,3 mSv, abdomen y pelvis 6,1 ± 0,3 mSv. La dosis de radiación aportada por el estudio TC se encuentra entre 0,46 mSv para la región del tórax en el estudio de ganglio centinela de mama y 2,3 mSv para el SPECT-CT óseo en la región de abdomen y pelvis. Conclusión: se logró estimar la dosis efectiva en los protocolos SPECT-CT de uso clínico más frecuente en población adulta y el aporte de los estudios TC a la dosis efectiva total siendo relativamente baja comparado con la dosis aportada por los radiofármacos administrados con la excepción del estudio de ganglio centinela donde la contribución del componente TC es aproximadamente la mitad de la dosis efectiva total.

Introduction: SPECT-CT Hybrid image technique combines the SPECT (single-photon emission computed tomography) image with the CT (computerized tomography) image to obtain both functional and anatomical images in the same study. The total effective ionizing radiation dose received in SPECT-CT studies may be estimated based on the effective dose from the radiopharmaceutical administered and the effective dose from the CT (computerized tomography) component. Objectives: the study aims to estimate the total effective dose in SPECT-CT protocols applied for the adult population, and to determine the additional contribution from the CT component to the total effective dose. Method: 258 SPECT-CT studies were evaluated to estimate the total effective dose from the administration of radiopharmaceuticals and low dose CT studies. Specific conversion factors for each radiopharmaceutical and area of the body explored with the CT were used to estimate radiation doses from both components. Results: total effective dose (average ± SD) in the SPECT-CT studies was: 12.4 ± 1.44 mSv in the myocardial perfusion study, 1.14 ± 0.25 mSv in the breast sentinel lymph node study, 8.6 ± 0.6 mSv in the parathyroid study, 1.48 ± 1.02 mSv in the thyroid study. As to bone studies, doses found were: 4.5 ± 0.3, in neck studies, 6.07 ± 0.3 mSv in thoracic studies and 6.1 ± 0.3 mSv in abdominal and pelvic studies. The radiation dose from the CT study ranges from 0.46 mSv for the thoracic region on the breast sentinel lymph node study to 2.3 mSv for the bone SPECT-CT study of the abdominal and pelvic region. Conclusions: we managed to estimate the effective dose in the the most frequently used SPECT-CT protocols for the adult population and the contribution of CT studies to the total effective dose. It was found to be relatively low when compared to the dose contributed by the radiopharmaceuticals administered, with the exception of the sentinel lymph node study for which the contribution from the CT study is approximately half the total effective dose.

Introdução: a técnica de imagem híbrida SPECT-CT combina a imagem de tomografia por emissão de fóton único (SPECT) com o estudo de tomografia computadorizada (TC), obtendo informações funcionais e anatômicas no mesmo estudo. A dose efetiva total de radiação ionizante recebida em estudos SPECT-CT pode ser estimada a partir da dose efetiva atribuível à atividade administrada do radiofármaco e da dose efetiva do componente de tomografia computadorizada (TC). Objetivos: estimar a dose efetiva total nos protocolos SPECT-CT utilizados na população adulta e determinar a contribuição adicional do estudo de TC na dose efetiva total. Método : 258 estudos SPECT-CT foram avaliados para estimar a dose efetiva total fornecida pela administração de radiofármacos e estudos de TC de baixa dose. Para estimar a contribuição de ambos os componentes, foram utilizados fatores de conversão específicos para cada radiofármaco e região explorada pela TC. ⁠ Resultados: a dose efetiva total (média ± DP) nos estudos SPECT-CT foi: 12,4 ± 1,44 mSv no estudo de perfusão miocárdica, 1,14 ± 0,25 mSv no linfonodo sentinela mamário, 8,6 ± 0,6 mSv paratireoide, 1,48 ± 1,02 mSv estudos de tireoide e ossos das regiões do pescoço 4,5 ± 0,3, tórax 6,07 ± 0,3 mSv, abdômen e pelve 6,1 ±0,3mSv. A dose de radiação fornecida pelo estudo de TC está entre 0,46 mSv para a região do tórax no estudo do linfonodo sentinela da mama e 2,3 mSv para o SPECT-CT ósseo na região do abdome e pelve. Conclusão: foi possível estimar a dose efetiva nos protocolos de SPECT-CT mais utilizados clinicamente na população adulta e a contribuição dos estudos de TC para a dose efetiva total, sendo relativamente baixa em relação à dose fornecida pelos radiofármacos administrados com a exceção do estudo do linfonodo sentinela onde a contribuição do componente TC é aproximadamente metade da dose efetiva total.

Diagnosis of Traumatic Bronchobiliary Fistula With Late 99m Tc-Mebrofenin SPECT/CT.

ABSTRACT: Bronchobiliary fistula (BBF) represents a rare disorder; it consists of abnormal interconnection between the biliary tract and bronchial trees. A 22-year-old woman with persistent chest pain, jaundice, and biliptysis was referred for hepatobiliary scintigraphy under clinical suspicion of a BBF. Patient medical history was consistent with biliary tree reconstruction secondary to an iatrogenic injury during cholecystectomy 4 years ago. Previous complementary studies (CT and MR cholangiopancreatography) were equivocal for diagnosis. Planar dynamic images of hepatobiliary scintigraphy in the first hour were inconclusive. A 24-hour SPECT/CT was performed and confirmed the BBF in a minimally invasive way.

Design, Synthesis and Preclinical Assessment of 99mTc-iFAP for In Vivo Fibroblast Activation Protein (FAP) Imaging.

Fibroblast activation protein (FAP) is expressed in the microenvironment of most human epithelial tumors. 68Ga-labeled FAP inhibitors based on the cyanopyrrolidine structure (FAPI) are currently used for the detection of the tumor microenvironment by PET imaging. This research aimed to design, synthesize and preclinically evaluate a new FAP inhibitor radiopharmaceutical based on the 99mTc-((R)-1-((6-hydrazinylnicotinoyl)-D-alanyl) pyrrolidin-2-yl) boronic acid (99mTc-iFAP) structure for SPECT imaging. Molecular docking for affinity calculations was performed using the AutoDock software. The chemical synthesis was based on a series of coupling reactions of 6-hidrazinylnicotinic acid (HYNIC) and D-alanine to a boronic acid derivative. The iFAP was prepared as a lyophilized formulation based on EDDA/SnCl2 for labeling with 99mTc. The radiochemical purity (R.P.) was verified via ITLC-SG and reversed-phase radio-HPLC. The stability in human serum was evaluated by size-exclusion HPLC. In vitro cell uptake was assessed using N30 stromal endometrial cells (FAP positive) and human fibroblasts (FAP negative). Biodistribution and tumor uptake were determined in Hep-G2 tumor-bearing nude mice, from which images were acquired using a micro-SPECT/CT. The iFAP ligand (Ki = 0.536 nm, AutoDock affinity), characterized by UV-Vis, FT-IR, 1H-NMR and UPLC-mass spectroscopies, was synthesized with a chemical purity of 92%. The 99mTc-iFAP was obtained with a R.P. >98%. In vitro and in vivo studies indicated high radiotracer stability in human serum (>95% at 24 h), specific recognition for FAP, high tumor uptake (7.05 ± 1.13% ID/g at 30 min) and fast kidney elimination. The results found in this research justify additional dosimetric and clinical studies to establish the sensitivity and specificity of the 99mTc-iFAP.

How and when is multiglandular disease diagnosed in sporadic primary hyperparathyroidism?

BACKGROUND: In total, ∼15% of patients with sporadic primary hyperparathyroidism have multiglandular disease, which may be suspected preoperatively but can only be confirmed intra or postoperatively. The study aim is to determine how and when patients are diagnosed with multiglandular disease and to what extent different modalities contribute. METHODS: Consecutive cases of sporadic primary hyperparathyroidism (2013-2019) undergoing initial exploration were reviewed from a single-institution prospective database. Preoperative single-photon emission tomography/computed tomography and neck ultrasound were routinely performed to help direct either bilateral or unilateral exploration guided by intraoperative parathyroid hormone monitoring using the dual criteria. Multiglandular disease was defined as either resection of >1 enlarged parathyroid or hypercalcemia at ≥6 months after single gland resection. RESULTS: Of 1,890 patients with sporadic primary hyperparathyroidism, multiglandular disease was identified in 254 (13.4%); 244 (96.1%) were diagnosed intraoperatively and 10 (3.9%) postoperatively. In these multiglandular disease patients, single gland disease was suggested on single-photon emission tomography/computed tomography in 54.0%, ultrasound in 49.2%, and both were concordant for single gland disease in 29.4%. Intraoperative multiglandular disease diagnosis was prompted by an inadequate intraoperative parathyroid hormone monitoring drop in 38.5%, by surgeon interpretation of imaging in 38.1%, by observing ipsilateral gland enlargement in 11.0%, by finding an initial gland <200 mg in 10.3%, and 2.0% had unexpected multiglandular disease during thyroidectomy. Multiglandular disease was diagnosed by postoperative hypercalcemia in 10 of 254 patients (4.9%). CONCLUSION: To avoid failure at parathyroidectomy for primary hyperparathyroidism, expert surgeons use multiple approaches to diagnose and manage multiglandular disease. Preoperative localization studies alone are insufficient, missing multiglandular disease in at least 30% of cases. All examined adjuncts are informative, including intraoperative parathyroid hormone monitoring, imaging, and intraoperative visual cues.

Evaluation of Traumatic Spinal Cord Injury in a Rat Model Using 99mTc-GA-5 as a Potential In Vivo Tracer.

Spinal cord injury (SCI) refers to the damage suffered in the spinal cord by any trauma or pathology. The purpose of this work was to determine whether 99mTc-GA-5, a radiotracer targeting Glial Fibrillary Acidic Protein (GFAP), can reveal in vivo the reactivation of astrocytes in a murine model with SCI. A method for the 99mTc radiolabeling of the mouse anti-GFAP monoclonal antibody GA-5 was implemented. Radiochemical characterization was performed, and radioimmunohistochemistry assays were used to evaluate the integrity of 99mTc-GA-5. MicroSPECT/CT was used for in vivo imaging to trace SCI in the rats. No alterations in the GA-5's recognition/specificity ability were observed after the radiolabeling. The GA-5's radiolabeling procedure implemented in this work offers a practical method to allow the in vivo following of this monoclonal antibody to evaluate its biodistribution and specificity for GFAP receptors using SPECT/CT molecular imaging.

Findings in [99mTc]MAA SPECT/CT in the diagnosis and follow-up of pulmonary embolism after infection by SARS-CoV-2 (COVID-19).

SARS-CoV-2 (COVID-19) infection is a current public health problem that has been shown to cause multiple complications, including pulmonary thromboembolism. The first presented case is a 59-year-old woman with a history of COPD, paroxysmal atrial fibrillation and COVID-19 infection in September 2020, consultation in December 2020 for atypical chest pain with suspected PE, AngioCT of pulmonary vessels was performed negative for emboli, subsequently [99mTc]Tc MAA SPECT/CT was indicated with a report of multiple triangular defects concerning acute pulmonary thromboembolism. A second case is a 70-year-old man with a history of dyslipidaemia, presented COVID-19 infection in September 2020 with a complication of PE with involvement of the left pulmonary artery, followed by [99mTc]Tc MAA SPECT/CT report multiple triangular and not triangles defects concerning pulmonary thromboembolism with signs of reperfusion.

Image-Guided Biopsy for Relapsed Neuroblastoma: Focus on Safety, Adequacy for Genetic Sequencing, and Correlation of Tumor Cell Percent With Quantitative Lesion MIBG Uptake.

PURPOSE: Many novel therapies for relapsed and refractory neuroblastoma require tumor tissue for genomic sequencing. We analyze our experience with image-guided biopsy in these patients, focusing on safety, yield, adequacy for next-generation sequencing (NGS), and correlation of tumor cell percent (TC%) with quantitative uptake on 123I-meta-iodobenzylguanidine (MIBG) single-photon emission computed tomography with computed tomography (SPECT/CT). MATERIALS AND METHODS: An 11-year retrospective review of image-guided biopsy on 66 patients (30 female), with a median age of 8.7 years (range, 0.9-49 years), who underwent 95 biopsies (55 bone and 40 soft tissue) of relapsed or refractory neuroblastoma lesions was performed. RESULTS: There were seven minor complications (7%) and one major complication (1%). Neuroblastoma was detected in 88% of MIBG- or fluorodeoxyglucose-avid foci. The overall NGS adequacy was 69% (64% in bone and 74% in soft tissue, P = .37). NGS adequacy within neuroblastoma-positive biopsies was 88% (82% bone and 96% soft tissue, P = .11). NGS-adequate biopsies had a greater mean TC% than inadequates (51% v 18%, P = .03). NGS-adequate biopsies had a higher mean number of needle passes (7.5 v 3.4, P = .0002). The mean tissue volume from NGS-adequate soft-tissue lesions was 0.16 cm3 ± 0.12. Lesion:liver and lesion:psoas MIBG uptake ratios correlated with TC% (r = 0.74, r = 0.72, and n = 14). Mean TC% in NGS-adequate samples was 51%, corresponding to a lesion:liver ratio of 2.9 and a lesion:psoas ratio of 9.0. Thirty percent of biopsies showed an actionable ALK mutation or other therapeutically relevant variant. CONCLUSION: Image-guided biopsy for relapsed or refractory neuroblastoma was safe and likely to provide NGS data to guide therapy decisions. A lesion:liver MIBG uptake ratio of ≥ 3 or a lesion:psoas ratio of > 9 was associated with a TC% sufficient to deliver NGS results.

Head-to-Head Comparison of 68Ga-PSMA-11 and 131I in the Follow-Up of Well-Differentiated Metastatic Thyroid Cancer: A New Potential Theragnostic Agent.

Introduction: Thyroid cancer is the main endocrine neoplasia worldwide, for which 131I therapy is the cornerstone treatment. One of the main problems of follow up in patients with this type of cancer, is the need for thyroglobulin stimulation, not to mention the poor availability of 123I or 124I, to perform studies with a higher degree of sensitivity. Prostatic Specific Membrane Antigen (PSMA) PET/CT has demonstrated to be quite useful in a diversified number of neoplasms, on behalf of its capacity of evaluating the extent of type II carboxypeptidase expression in vascular endothelium. The end point of this article is to assess whether this novel image method possesses applicability in thyroid neoplasms follow up, for diagnostic and potentially therapeutic purposes. Methods: We retrospectively evaluated well differentiated metastatic thyroid cancer patients, who underwent a post therapeutic 131I dose whole body scan (WBS) and complementary SPECT/CT, as well as 68Ga-PSMA-11 PET/CT. Results: Ten patients with differentiated thyroid cancer were included, of whom 80% were women and 20% men, mean age was 58 years old (± 11.6). Sixty-four metastatic lesions were analyzed, 67.19% had papillary histology and 32.81% were follicular type, the most affected site of metastases was bone in 57.81%, followed by lung 17.19%, lymph nodes 7.81%, postoperative thyroid bed 4.69%, brain 4.69% and others 7.81%. 68Ga PSMA-11 PET/CT detected 64/64 lesions, all of them also identified by computed tomography (CT), whereas 131I SPECT/CT detected 55/64 lesions. Discrepant lesions were localized in lung 44.4%, brain 22.2%, postoperative thyroid bed 11.1%, lymph nodes 11.1% and bone 11.1%. The degree of correspondence among observers was outstanding for both radiotracers, but close upon perfect for PSMA-11 (κ = 0.98; 95% CI, 0.80 - 0.91), as opposed to 131 I (κ = 0.86; 95% CI, 0.71 - 0.76). Conclusions: 68Ga-PSMA PET/CT showed an utterly superior capability for metastatic lesion detection when compared to 131I SPECT/CT. These findings suggest that PSMA PET/CT could possibly and precociously identify radioiodine refractoriness. PSMA uptake values not only expedite diagnosis, but also award it the ability to be used for therapeutic intents.

The additional prognostic value of myocardial perfusion SPECT in patients with known coronary artery disease with high exercise capacity.

BACKGROUND: The prognostic value of myocardial perfusion imaging (MPI) in patients with known coronary artery disease (CAD) and high exercise capacity is still unknown. We sought to determine the MPI additional prognostic value over electrocardiography (ECG) stress testing alone in patients with known CAD who achieved ≥ 10 metabolic equivalents (METs). METHODS AND RESULTS: We evaluated 926 patients with known CAD referred for MPI with exercise stress. Patients were followed for a mean of 32.4 ± 9.7 months for the occurrence of all-cause death or nonfatal myocardial infarction (MI). Those achieving ≥ 10 METs were younger, predominantly male, and had lower prevalence of cardiovascular risk factors. Patients reaching ≥ 10 METs had a lower annualized rate of hard events compared to their counterparts achieving < 10 METs (1.13%/year vs 3.95%/year, P < .001). Patients who achieved ≥ 10 METs with abnormal scans had a higher rate of hard events compared to those with normal scans (3.37%/year vs 0.57%/year, P = .023). Cardiac workload < 10 METs and an abnormal MPI scan were independent predictors of hard events. CONCLUSIONS: MPI is able to stratify patients with known CAD achieving ≥ 10 METs for the occurrence of all-cause death and nonfatal MI, with incremental prognostic value over ECG stress test alone.

Incidental CT Findings Suspicious for COVID-19-Associated Pneumonia on Nuclear Medicine Examinations: Recognition and Management Plan.

Some patients undergoing routine SPECT/CT and PET/CT examinations during the COVID-19 pandemic may incidentally reveal findings of COVID-19-associated pneumonia (C-19AP) on localizing CT. It is critical for nuclear medicine physicians to develop diagnostic skills for timely recognition of typical findings of C-19AP on a localizing CT. Furthermore, it is our responsibility to know the optimal practices for safely isolating and managing such patients while protecting the staff, other patients at the facility, family and/or friend accompanying the patients, and the public in general from risky exposure to COVID-19 sources. We offer several steps following an encounter suspicious of C-19AP.

Hybrid (2D/3D) Dosimetry of Radiolabeled Gold Nanoparticles for Sentinel Lymph Node Detection in Patients with Breast Cancer.

Previously, we reported the preparation and preclinical studies of 99mTc-labeled gold nanoparticles-mannose (99mTc-AuNP-mannose) with potential for sentinel lymph node (SLN) detection by using nuclear medicine procedures. This study aimed to evaluate the biokinetics and hybrid (2D/3D) dosimetry of 99mTc-AuNP-mannose in five patients with breast cancer under a sentinel lymph node detection protocol. Anterior and posterior whole-body planar images (2D, at 0.5, 2, 6, and 24 h) and single-photon emission computed tomography (3D at 6.5 h)/computed tomography (SPECT/CT) images were acquired after 99mTc-AuNP-mannose administration (37 MBq). Through a hybrid quantification method, activity in tissues of interest at the different acquisition times was determined and integrated over time to obtain the total nuclear transformations (N), as well as the mean residence time, in each tissue. N values and the OLINDA code were used for estimating the internal radiation absorbed doses. Results demonstrated that 99mTc-AuNP-mannose successfully accumulates and remains up to 24 h in the sentinel lymph node without detectable migration to other lymph nodes and no side effects on patients. Negligible absorption of the radiolabeled nanoparticles into the circulatory system was observed, from which the radio-nanosystem is rapidly eliminated by kidneys. Hybrid (2D/3D) dosimetry evaluations showed equivalent doses to SLN, breast, and kidneys of 172.34, 5.32, and 0.08 mSv/37 MBq, respectively, with an effective dose of 2.05E - 03 mSv/MBq. The mean effective residence time in SLN was 0.92 h. This preliminary study indicates that the use of 99mTc-AuNP-mannose for successful SLN detection in patients is safe, producing an effective dose at the level recommended for diagnostic studies (<10 mSv).

18F-fluorodeoxyglucose use after cardiac transplant: A comparative study of suppression of physiological myocardial uptake.

BACKGROUND: 18F-fluorodeoxyglucose (FDG) has been useful in the evaluation of myocardial inflammatory processes. However, it is challenging to identify them due to physiological 18F-FDG uptake. There are no publications demonstrating the application of FDG in post-transplant rejection in humans yet. The aim of this study is to determine the feasibility of suppression of myocardial FDG uptake in post-transplant patients, comparing three different protocols of preparation. METHODS: Ten patients after heart transplantation were imaged by FDG associated with three endomyocardial biopsies (EMB), scheduled in the first year after the procedure. Before each imaging, patients were randomized to one of three preparations: (1) hyperlipidic-hypoglycemic diet; (2) fasting longer than 12 hours; and (3) fasting associated with intravenous heparin. All patients would undergo the three methods. FDG images were analyzed using visual analysis scores and relative radiotracer cardiac uptake (RRCU). RESULTS: The suppression rate of radiotracer activity ranged from 55% to 62%. Visual analysis showed that preparation 3 presented less efficacy in the suppression compared to the others. However, RRCU did not show difference between the preparations. CONCLUSIONS: Suppression of physiological myocardial FDG uptake after cardiac transplantation is feasible. The usefulness of heparin in the suppression is unclear.

Inalação/perfusão pulmonar por SPECT-CT e ANGIO-TC de tórax no diagnóstico do tromboembolismo pulmonar em centro oncológico / Pulmonary inhalation/perfusion by SPECT-CT and ANGIO-TC of thorax in the diagnosis of pulmonary thromboembolism in oncologic center

Introdução: O Tromboembolismo Pulmonar (TEP) é uma entidade clínica e patológica caracterizada pela obstrução de coágulos sanguíneos na circulação pulmonar. Estes coágulos geralmente são oriundos da circulação venosa sistêmica estando intrinsecamente ligada à trombose venosa profunda (TVP), com redução ou escassez do fluxo sanguíneo para a área afetada, podendo levar o paciente rapidamente a morte. O TEP é evento muito comum em pacientes hospitalizados e com câncer. Hoje seu diagnóstico é definido pelas técnicas de ANGIO-TC de tórax (padrão ouro) e I/P por SPECT-CT. A técnica de I/P por SPECT-CT vem demonstrando alta acurácia para o diagnóstico de TEP, e por ser uma técnica de baixa dose de radiação e com definição tomográfica é de grande valia considera-la para o diagnóstico de TEP em pacientes oncológicos que frequentemente estão sendo submetidos a procedimentos de radiação e quimioterápicos. Objetivos: O objetivo do presente estudo é analisar o desempenho diagnóstico e a concordância entre os exames realizados pelas técnicas de Inalação/Perfusão Pulmonar por SPECT-CT e da ANGIO-TC de Tórax no diagnóstico do TEP em um Centro Oncológico. Avaliar o perfil dos pacientes e o Impacto na conduta médica. Métodos: Estudo de coorte descritivo, retrospectivo, quantitativo, qualitativo e unicêntrico; realizado através da análise de exames de Tomografia Computadorizada de Tórax-Protocolo para Pesquisa de TEP com contraste venoso iodado, realizados no Setor da Tomografia. E da análise dos exames de I/P por SPECT-CT com a inalação do DTPA99m e administração endovenosa do Macro-Agregado de Albumina99m ou MAA99m no Serviço de Medicina Nuclear do Departamento de Imagem do A.C.Camargo Câncer Center de Janeiro de 2015 a Maio de 2018. Resultados: Foi analisado um total de 410 exames e 363 pacientes. Duzentos e noventa e nove pacientes foram diagnosticados como negativos pra TEP e 64 pacientes como positivos pra TEP. Trezentos e trinta e cinco pacientes realizaram o exame de ANGIO-TC de tórax, 75 realizaram o exame de I/P pulmonar por SPECT-CT e 47 pacientes realizaram os dois exames. Oitenta por cento dos pacientes oncológicos apresentaram mais de uma das comorbidades além do câncer, sendo as mais prevalentes e que demonstraram associação com o diagnóstico de TEP o histórico de TEP/TVP, o Uso de anticoagulantes, Doenças pulmonares pré-existentes e HAS. Os tipos de câncer que demonstraram associação com o diagnóstico de TEP foram Câncer de pulmão, pâncreas e cérebro. Sendo mais prevalente o Câncer de pulmão nos pacientes com suspeita e diagnóstico de TEP. Os métodos de I/P pulmonar por SPECT-CT e ANGIO-TC de tórax obtiveram uma boa concordância nos resultados, e não houve impacto na conduta médica mediante o diagnóstico e tratamento nos dois Grupos analisados. Conclusão: Os métodos de I/P pulmonar por SPECT-CT e ANGIO-TC de tórax demonstraram ser ambos confiáveis e com alta acurácia para o diagnóstico do TEP em pacientes oncológicos. O SPECT-CT demonstrou ótima acurácia para o diagnóstico de TEP negativo podendo ser preferível e mais indicado para afastar TEP em pacientes oncológicos dada a sua menor radiação, porém para o diagnóstico de TEP positivo a ANGIO-TC de tórax ainda é mais indicada (AU)

Introduction: Pulmonary thromboembolism (PTE) is a clinical and pathological entity characterized by obstruction of blood clots in the pulmonary circulation. These clots usually come from the systemic venous circulation and are intrinsically linked to deep vein thrombosis (DVT), with reduced or scarce blood flow to the affected area, which can lead the patient quickly to death. PTE is a very common event in hospitalized patients with cancer. Today its diagnosis is defined by the techniques of ANGIO-TC of thorax (gold standard) and I/P by SPECT-CT. The technique of I/P by SPECT-CT has demonstrated high accuracy for the diagnosis of PTE, and because it is a technique of low radiation dose and with tomographic definition is of great value to consider it for the diagnosis of PTE in oncologic patients who are often undergoing radiation and chemotherapy procedures. Objectives: The objective of this study is to analyze the diagnostic performance and agreement between the tests performed by the inhalation/perfusion Pulmonary SPECT-CT and the ANGIO-TC Chest techniques in the diagnosis of PTE in an Oncologic Center. To evaluate the profile of patients and the impact on medical conduct. Methods: Descriptive, retrospective, quantitative, qualitative and unicentric cohort study; performed through the analysis of Thoracic Computed Tomography-Protocol for PTE Research with iodinated venous contrast, performed in the Tomography Sector. And the analysis of SPECT-CT I/P exams with inhalation of DTPA99m and intravenous administration of Macro-Agregado de Albumina99m or MAA99m at the Nuclear Medicine Service of the Imaging Department of the A.C.Camargo Cancer Center from January 2015 to May 2018. Results: A total of 410 tests and 363 patients were analyzed. Two hundred and ninety-nine patients were diagnosed as negative for TEP and 64 patients as positive for TEP. Three hundred and thirty-five patients underwent ANGIO-TC chest exam, 75 underwent SPECT-CT lung I/P exam and 47 patients underwent both exams. Eighty percent of oncologic patients presented more than one of the comorbidities besides cancer, being the most prevalent and that showed association with the diagnosis of PTE the history of PTE/TVP, the use of anticoagulants, pre-existing lung diseases and SAH. The types of cancer that demonstrated association with the diagnosis of PTE were Lung, pancreas and brain cancer. Lung cancer is more prevalent in patients with suspected and diagnosed PTE. The lung I/P methods by SPECT-CT and ANGIO-TC of thorax obtained a good agreement in the results, and there was no impact in the medical conduct through diagnosis and treatment in the two Groups analyzed. Conclusion: The methods of pulmonary I/P by SPECT-CT and ANGIO-TC of thorax demonstrated to be both reliable and with high accuracy for the diagnosis of PTE in oncologic patients. The SPECT-CT showed excellent accuracy for the diagnosis of negative PTE and may be preferable and more indicated to rule out PTE in oncologic patients due to its lower radiation, but for the diagnosis of positive PTE the chest ANGIO-TC is even more indicated (AU)

Hepatobiliary scintigraphy in the study of complications in adult patients after liver transplant. Description of the experience. / Gammagrafía hepatobiliar en el estudio de las complicaciones del trasplante hepático en adultos. Descripción de la experiencia.

OBJECTIVE: To show the experience of the use of hepatobiliary scintigraphy in patients with suspected complications after liver transplantation in a high complexity centre. MATERIAL AND METHOD: Retrospective, observational and descriptive study. All consecutive adult patients with liver transplantation between January 2013 and February 2018 were included, with one or more hepatobiliary scintigraphy during the early or late postoperative period. A total of 58 studies were analyzed in 38 patients (22 men and 16 women). Mean age: 48 years. In 34/38: cadaverous donor (89%), and in 4 (11%): a living donor. Demographic data and relevant information regarding the transplant were obtained, and the result was related to the surgical findings to determine the correlation between them. The influence of the test on the final clinical decisions was evaluated. RESULTS: Findings: 9 scans (14%) were normal, 36 studies were negative, and 21 were positive for biliary complications. Of the total of 58 studies, 50 (86%) had impact on the clinical behaviour of observation or intervention. All the patients with findings of biliary complications (21/21; 100%) had clinical repercussion since 18/21 patients were taken to invasive studies or treatments, and 3/21 patients continued in medical management for findings of non-surgical biliary complications. In 14/18 patients taken to studies or procedures, correlation was found with the scintigraphic study. In 24/36 (66%) of patients with negative scintigraphy, an impact on clinical behaviour was found. CONCLUSION: Hepatobiliary scintigraphy is a simple, non-invasive, reliable, current and available form for the early study of biliary complications in patients with liver transplantation. Important hepatocellular dysfunction should be taken into account as a frequent cause of false negative studies.