Diffuse Uptake Research Articles

SAT569 Papillary Thyroid Carcinoma With Renal Metastasis Treated With Radioactive Iodine: A Case Report

Abstract Disclosure: A.A. Apa-ap: None. M.B. Sedurante: None. J. Lacuata: None. J. Gacula: None. V. Lee: None. M.L. Hernandez: None. INTRODUCTION. Papillary thyroid cancer (PTC) is one of the most treatable cancers in comparison to undifferentiated thyroid malignancies. It advances slowly, and there is only 1-4 percent of cases of distant metastases. Renal involvement from PTC is very rare with an incidence of 0.47 percent. CASE DESCRIPTION. This paper describes a 34-year-old Filipino female presenting with an 8-year history of hoarseness and a gradually enlarging anterior neck mass. Metastatic workup revealed innumerable bilateral pulmonary nodules bilateral cervical lymphadenopathy, and bilateral renal mass on CT scan. The right pole of the kidney shows a solid heterogeneously enhancing partially-exophytic focus measuring 4.9 x 4.2 x 4.3cm likely a primary renal cell carcinoma versus metastasis. The left renal mass shows a hypodense non-enhancing partially-exophytic focus measuring 3.9 x 3.6 x 3.6cm probably a renal cyst. Clinically, the patient did not show any urinary symptoms and creatine clearance was normal. The patient underwent total thyroidectomy and neck dissection and histopathology revealed PTC. The patient underwent simultaneous ultrasound right renal mass biopsy which revealed few fragments of thyroid tissues with atypia most likely representative of metastasis of PTC. Since the radiographic finding was suggestive of a renal cyst, the left renal mass was not biopsied. Patient refused nephrectomy and underwent 1 cycle of Radioactive Iodine (RAI) Therapy. Post therapy whole body scan showed mildly increased and diffuse tracer uptake activity in bilateral lungs and large avid focus, approximately 5.0 x 4.4 cm, seen in the inferior pole of the right kidney. Surveillance showed increased thyroglobulin. To date, the patient still refused surgery and is contemplating undergoing another cycle of RAI therapy. DISCUSSION. Due to the rarity of the metastatic site, the ideal course of treatment for this illness is unknown. To our knowledge, there are only approximate of 30 case reports on WDTC with renal metastasis in the literature. Presentation: Saturday, June 17, 2023

SAT581 Parathyroid Hormone Related Protein-induced Hypercalcemia In Medullary Thyroid Carcinoma In Pediatric Patient With MEN2A

Abstract Disclosure: S.A. Ackah: None. L.A. DiMeglio: None. J.C. Sanchez: None. G.C. Geddes: None. Background: PTHrp is a well-known cause of hypercalcemia of malignancy. Although PTHrp can often be detected in papillary, follicular and anaplastic thyroid cancers it does not always lead to hypercalcemia. Okotur 2007 described PTHrp in an adult medullary thyroid carcinoma (MTC). No pediatric cases have been described. Case: 8 year old female presented on transfer from hospital in Kenya where she had been admitted for three months with diarrhea and malnourishment (weight Z-score -6.5). She had been initially treated for aspiration pneumonia with negative testing for HIV, tuberculosis, stool cultures and parasites. At our facility, chest, abdomen and pelvis imaging were interpreted as an abscess from perforated appendicitis, bilateral hydroureteronephrosis, bilateral multifocal pneumonia and coronary artery ectasia. She experienced respiratory status decline requiring intubation. Further work up included consults and testing by infectious disease, genetics, immunology, cardiology, gastroenterology, pulmonology, and urology. In Kenya, the patient was initially normocalcemic and the calcium then slowly increased, so that on admission to our facility was found to have calcium 18.3 mg/dL (8.5-10.5), phosphorous 3.3 mg/dL (3.4-5.5), Creatinine 0.3 mg/dL (0.3-0.8), albumin 3.5 g/dL (3.5-4.7), PTH 5 pg/mL(10-65), TSH 1.9 mIU/ml (0.4-4.2), Free T4 0.8 ng/dL(0.6-1.5). IV hydration and pamidronate 0.5 mg/kg x 3 days administration resolved the hypercalemia. Rapid whole genome testing revealed a de novo pathogenic variant in RET (RET NM_020975.6 c.2753T>C; p.M918T) previously reported in individuals with MEN type 2A and 2B phenotypes. Thyroid ultrasound showed 2 nodules. FNA of both showed MTC; MTC was also present on lung biopsy. Screening labs obtained then showed PTHrp 301 pmol/L(adult range 0.0-3.4), Calcitonin 1433 pg/mL(0.0-5.1), VIP <13 pg/mL(0-60), Gastrin 45 pg/mL(0-100), Chromogranin A 4049 ng/mL(0-103), CEA123.7 ng/mL(0.0-2.5), metanephrine 0.91 nmol/L(0.00-0.49), normetanephrine 0.48 nmol/L(0.00-0.89). Bone scan showed diffusely diminished physiological uptake in the growth plates and diffuse bilateral lung uptake. Due to concern about ability to tolerate thyroidectomy, the patient was begun on selpercatinib, an oral chemotherapeutic agent specifically for tumors with disruption of RET gene. On day 11 of treatment, she was extubated to noninvasive respiratory support. Now, 3 months out from pamidronate and her hypercalcemia has not recurred. Conclusions: Hypercalcemia in pediatric patients with low PTH should prompt further workup including PTHrP measurement. In this case, we report a case of a child with MEN 2A and metastasized MTC with hypercalcemia attributable to PTHrp secretion.

SAT490 Graves’ Disease In Remission Aggravated By Himalayan Salt Consumption

Abstract Disclosure: M.K. Shakir: None. K.F. Brown: None. J.S. Hatfield: None. N.O. Vietor: None. T.D. Hoang: None. Introduction: In iodine-replete countries, iodine-induced thyrotoxicosis may occasionally develop after ingestion or therapy with high doses of iodine. Recently, Himalayan salt has become very popular to bridge iodine deficiency, control hypothyroidism, and improve thyroid function. We report a patient with a history of treated Graves’ disease (GD) who developed acute thyrotoxicosis following the use of Himalayan salt. Case report: A 58-year-old woman presented with symptoms of heat intolerance, and unexpected 18-lbs weight loss over 3 months. Physical examination: HR 108 bpm, BP 110/70 mm Hg, normal eye examination, thyroid 45 gms, diffusely enlarged. Examinations of the heart, lungs and abdomen were normal. Lab tests: TSH 0.01 IU/mL, free T4 3.8 ng/dL, T3 308 pg/dL, thyrotropin receptor Ab 4.2 IU/L (<1.0), and thyroid stimulating immunoglobulin 1.89 1U/L (0.06-0.55). The I131 uptake was 60% at 4 hours and the thyroid scan revealed diffuse homogenous uptake confirming GD. She was treated with methimazole (MMI) for 2 years and remission was achieved. MMI was stopped and she remained euthyroid. Twelve months later, she developed hyperthyroid symptoms with a 15-lb weight loss, palpitations, and anxiety. Examination confirmed a 50-gram diffuse goiter and other physical findings consistent with hyperthyroidism. She admitted that she had been taking Himalayan salt (approximately 10 grams daily) in place of regular salt for the past 6 months. Lab tests confirmed recurrent GD: TSH <0.01 IU/mL, FT4 4.1 ng/dL, total T3 278 pg/dL, and I131 uptake was 55% at 24 hours. A 24-hours urine iodine was 898 mcg (normal 100-199) and plasma iodine level was 484 mcg/L (normal 52-109). A diagnosis of iodine-induced recurrence of GD was made, and she was treated with MMI and low iodine diet. After 3 months, she improved significantly and was able to discontinue the MMI by 6 months. A follow- up urine iodine was 189 mcg/L with a plasma iodine level of 78 mcg/L. Subsequently she remained euthyroid for an additional 18 months of follow-up without any treatment. Conclusion: The recommended daily dietary allowance for iodine in adults is 150mcg. Himalayan rock salt may provide a rich source of iodine and consumption of large amounts can lead to iodine excess. However, the available studies do not provide the iodine content in commercially available Himalayan salt preparations. Although the Himalayan salt is advertised to have beneficial effects in patients with thyroid disorders, this food supplement may have deleterious effects in susceptible patients who do not have iodine deficiency, have GD, or are at risk for thyrotoxicosis. Indeed, Himalayan salt use exacerbated GD in our patient, as evidenced by iodine overdose during acute exacerbation and resolution of GD with iodine normalization and low dose MMI. We recommend that patients with thyroid disorders be educated regarding Himalayan salt use. Presentation Date: Saturday, June 17, 2023

FRI564 Thymic Hyperplasia In Graves' Disease: An Under-recognized Association

Abstract Disclosure: S. Nachum: None. A. Rivadeneira: None. K.N. Kobaly: None. Association of thymic hyperplasia (TH) with Graves’ disease (GD) is rare and underrecognized. In an era of increased diagnostic imaging, incidental findings of thymic masses in patients with GD may be increasingly identified and awareness of this association may reduce unnecessary interventions. We report three cases of GD with TH at presentation, one of which includes resolution of TH. CASE 1: 56 year-old man with unintentional weight loss, palpitations and eye discomfort was diagnosed with GD (TSH <0.015, FT4 4.47, TRAB 8.18, TSI 8.51). He had an incidental 3x3 cm anterior mediastinal mass on a chest CT. MRI chest suggested TH. Myasthenia gravis antibodies were negative. I-123 uptake and scan showed diffusely increased uptake within the thyroid gland and no increased uptake in the upper chest corresponding to mediastinal mass. Initiation of methimazole normalized thyroid function. CT chest at 9 months showed near resolution of the anterior mediastinal soft tissue density compatible with resolving TH. CASE 2: 23 year-old woman presented with insomnia, palpitations, and neck pain and was found to have GD (TSH <0.01, FT4 2.75, TRAB 9.16, TSI 8.84). CT neck obtained due to pain showed diffuse enlargement of the thyroid and a soft tissue density in the partially imaged superior mediastinum. Methimazole was started. Further evaluation of mass is pending. CASE 3: 35 year-old man presented with atrial fibrillation and was diagnosed with hyperthyroidism (TSH < 0.01, FT4 5.55). Tc-99m pertechnetate scan showed diffuse uptake consistent with GD. Methimazole was started. CT chest obtained due to concern for pulmonary embolism showed a 12.6 x 3.0 cm anterior mediastinal mass. HCG was undetectable. Further evaluation of mass is pending. Discussion: TH is thought to occur due to hormonal excess stimulating the thymic cortex and immunological mechanisms that result in formation of medullary lymphoid follicles.1 The incidence of TH in GD is unknown as diagnostic imaging is not routinely obtained. A study of thymic biopsies in patients undergoing thyroidectomy found 38% of patients with thyrotoxicosis had histological evidence of TH.2 This benign condition improves with treatment of GD, with decreased thymic size after 5-24 months of treatment with antithyroid drugs.3 In the absence of a discrete mass, invasion of other tissues or calcifications, repeat imaging after 6 months with regression of TH by 50% obviates the need for biopsy.1 Biopsy and thymectomy should be deferred when thyrotoxic due to risk of precipitating thyroid storm4 and be reconsidered if thymus fails to regress on repeat imaging. Additional guidance for observation is needed as the differential diagnosis for mediastinal mass includes diseases warranting more urgent diagnosis and intervention. Identification of high-risk patient characteristics or imaging findings may be of clinical utility in this circumstance. Presentation: Friday, June 16, 2023

Elevated prostate-specific antigen in Paget’s disease

ABSTRACT A 70-year-old man diagnosed with acinar adenocarcinoma prostate (Gleason score 4 + 4 = 8) underwent bone scintigraphy due to high serum prostate-specific antigen level (224 ng/mL; normal <4 ng/mL). Bone scan revealed moderately increased diffuse tracer uptake in the right hemipelvis, while the rest of the scan appeared normal, leading to suspicion of Paget’s disease. Gallium-68-prostate-specific membrane antigen (PSMA) positron emission tomography–computed tomography scan (CT) showed a PSMA-avid lesion in the left lobe of the prostate, with no PSMA uptake in the areas of diffuse sclerosis in the right hemipelvis, as seen on CT. This confirmed the diagnosis of Paget’s disease.

Subacute thyroiditis: clinical significance of diffuse 18-fluorodeoxyglucose uptake. Case report

Background. Subacute thyroiditis is a rare inflammatory thyroid disease presumably associated with viral infection, including COVID-19. It accounts for about 5% of all thyroid diseases.
 Materials and methods. A clinical case of de Quervain's subacute thyroiditis in a patient with diffuse hypermetabolic 18-fluorodeoxyglucose uptake by the thyroid gland is presented.
 Results. A 61-year-old patient with no history of thyroid disorders 3 weeks after COVID-19 experienced fever in the evenings (37.839.8C). He had moderate pain in the thyroid gland with radiation to the jaw, severe weakness, hand tremors, shivers, 12 kg weight loss, and sweating. These symptoms lasted for 3 weeks. Physical examination showed an enlarged thyroid gland, dense and extremely tender, especially its left lobe. Ultrasound showed an enlarged thyroid gland with a heterogeneous structure and large hypoechoic areas in both lobes up to 47 mm with fuzzy contour. Color Doppler imaging revealed reduced blood flow. Combined positron-emission and X-ray computed tomography with 18-fluorodeoxyglucose showed an increased diffuse uptake of the radiopharmaceutical in the thyroid gland and enlargement of its lobes, SUVmax 10.55. Blood thyroid-stimulating hormone is low, free triiodothyronine and thyroxine are high, and ferritin concentration is markedly increased, consistent with thyrotoxicosis. A fine-needle aspiration biopsy was performed. Cytology confirmed de Quervain's subacute thyroiditis. Glucocorticoids and nonsteroidal anti-inflammatory drugs were administered. Four weeks after the treatment, the clinical manifestations resolved. The patient was assessed in 6 months. Ultrasound showed a thyroid gland of regular size with smooth contours; color Doppler mapping revealed normal blood flow. Thyroid-stimulating hormone, triiodothyronine, and thyroxine were within reference ranges.
 Conclusion. The SARS-CoV-2 virus can be regarded as the cause of subacute thyroiditis. Combined positron-emission and X-ray computed tomography with 18-fluorodeoxyglucose showed diffuse intensive radiopharmaceutical uptake in the thyroid gland. Cytology is the basis for differential diagnostics. Glucocorticoids and nonsteroidal anti-inflammatory drugs are the first-choice agents.

Multiple myeloma with diffuse uptake on 18F-PSMA-1007 positron emission tomography/computed tomography: a case description and literature review.

Multiple myeloma with diffuse uptake on 18F-PSMA-1007 positron emission tomography/computed tomography: a case description and literature review.

Extensive cardiac FDG uptake in a patient with AL amyloidosis

Cardiac AL amyloidosis is a medical emergency causing rapid deterioration of cardiac function; however, it remains to be a diagnostic challenge especially when presenting with unusual symptoms and clinical findings. We present case of a 44-year-old patient with typical angina, persistently elevated troponin and normal epicardial coronary arteries. He was initially treated for myocarditis due to chest pain with troponin rise. However, CMR finding of subendocardial enhancement, increased native T1 values as well as extensive diffuse FDG uptake on PET-CT also suggested inflammatory cardiac conditions. Rapid decline in LV function and clinical deterioration led to further investigations including serum free light chains and bone marrow biopsy which confirmed systemic AL amyloidosis. Although the pathophysiology of unusual FDG PET-CT findings remains unknown, marked myocardial FDG uptake might have been caused by various features that were associated with AL amyloidosis including myocardial cell toxicity/inflammation or microvascular dysfunction. Awareness of these features specific to AL amyloidosis among physicians and description of associated cardiac FDG uptake findings has a potential to aid early diagnosis.

Diagnostic and Prognostic Value of 18F-FDG PET/CT in Bone Marrow Infiltration of Newly Diagnosed Diffuse Large B-Cell Lymphoma

To explore the diagnostic value of 18F-FDG PET/CT in bone marrow infiltration (BMI) of newly diagnosed diffuse large B-cell lymphoma (DLBCL), compared with the results of bone marrow biopsy (BMB) and investigate whether the BMI diagnosed by 18F-FDG PET/CT and other factors have independent prognostic values. Ninety-four newly diagnosed DLBCL patients who underwent PET/CT in Clinical Medical College of Shanghai General Hospital of Nanjing Medical University were included. BMB was performed within 2 weeks before or after PET/CT, and standardized treatment was performed after PET/CT. The manifestations of bone marrow (BM) FDG uptake were recorded. The diagnostic criteria of BMI were BMB positive or focal BM FDG uptake confirmed by imaging follow-up. The relationship between clinical features and BM FDG uptake and the values of PET/CT and BMB in the diagnosis of BMI was analyzed. The progression-free survival (PFS) was analyzed by Kaplan-Meier survival curves, log-rank test was used to compare PFS rate, and Cox regression model was used to analyze the independent risk factors affecting PFS. Among 94 DLBCL patients, 34 patients showed focal BM uptake (fPET), 7 patients showed super BM uptake (sBMU), 11 patients showed diffuse homogenous uptake higher than liver (dPET), and the other 42 patients had normal BM uptake (nPET) (lower than liver). BMB positive was found in all sBMU patients, in 20.6%(7/34) of fPET patients, and in 27.3% (3/11) of dPET patients. All nPET patients had negative BMB results. dPET patients were associated with lower hemoglobin level and leukocyte count compared with nPET group (P < 0.001, P =0.026). Compared with fPET patients, sBMU patients were more likely to have B symptoms and elevated lactate dehydrogenase (LDH). A total of 44 patients were diagnosed BMI, including 17 cases with BMB+. The sensitivity and specificity of BMB in the diagnosis of BMI was 38.6% (17/44) and 100% (50/50), respectively. Using fPET and sBMU as criteria of PET BMI, the diagnostic sensitivity and specificity of PET/CT was 93.2% (41/44) and 100% (50/50), respectively. Kaplan-Meier analysis showed that there was no significant difference in 2-year PFS rate between nPET and dPET patients (P >0.05), while sBMU patients had lower 2-year PFS rate compared with fPET patients (P < 0.001). Multivariate analysis showed that higher Ann Arbor stage (HR=9.010, P =0.04) and sBMU (HR=3.964, P =0.002) were independent risk factors affecting PFS. Increased BM FDG uptake of DLBCL can be manifested as dPET, fPET and sBMU. fPET and sBMU can replace BMB to diagnose BMI. Although dPET cannot completely exclude the possibility of BMI, it does not affect the prognosis, so it can be diagnosed as PET BMI negative. sBMU is an independent prognostic risk factor.

ACE2 PET in healthy and diseased conditions

AbstractAngiotensin converting enzyme 2 (ACE2) played a critical role in regulating renin‐angiotensin‐aldosterone system (RAAS). In this research, 68Ga‐cyc‐DX600 was synthesized as PET tracer of ACE2 imaging. ACE2 positron emission tomography/magnetic resonance (PET/MR) was preliminary administered on twelve healthy volunteers, and the images were normalized and registered to establish the standard model of ACE2 PET. In diseased conditions, 68Ga‐cyc‐DX600 PET and 18F‐FDG PET were compared for COVID‐19 (one in acute phase and three in post‐COVID), anemia (n = 1) and malignancies (n = 2) to evaluate the diagnostic efficiency. 68Ga‐cyc‐DX600 PET was of a definite ACE2 dependence. For the tracer uptake of ACE2 PET/MR of female and male, differences existed in salivary glands, upper respiratory tract and kidneys, meanwhile, age, and body mass index (BMI) were also the confounding factors. RAAS‐related tissue and organs were of the relatively higher tracer uptake, such as SUVmean of cardiac chamber (3.786 ± 1.495), liver (5.342 ± 2.267), spleen (4.465 ± 2.508), and kidney (4.906 ± 1.619 for female and 8.431 ± 5.179 for male). For COVID‐19, ACE2 PET revealed ACE2 fluctuations, particularly in the susceptible organs, including liver, spleen and testis. In the case of anemia, the activated local RAS in the bone marrow was of diffuse high tracer uptake. ACE2 PET of malignancies added supplementary information to FDG PET. 68Ga‐cyc‐DX600‐based ACE2 PET models were established for visually monitoring of whole‐body ACE2 expression. The feasibility of ACE2 PET in supervising disease was primarily proved in COVID‐19, anemia and malignancies as providing a comprehensive view on the disease process and functional recovery.

Cardiac fludeoxyglucose-18 positron emission tomography in genotype-positive arrhythmogenic cardiomyopathy

BackgroundMyocardial inflammation contributes to the pathogenesis of arrhythmogenic cardiomyopathy (ACM), a clinically and genetically heterogenous disorder. Due to phenotypic overlap, some patients with genetic ACM may be evaluated for an underlying inflammatory cardiomyopathy. However, the cardiac fludeoxyglucose (FDG) positron emission tomography (PET) findings in ACM patients have not been elucidated. MethodsAll genotype-positive patients in the Mayo Clinic ACM registry (n = 323) who received a cardiac FDG PET were included in this study. Pertinent data were extracted from the medical record. ResultsCollectively, 12/323 (4%; 67% female) genotype-positive ACM patients received a cardiac PET FDG scan as part of their clinical evaluation (median age at scan 49 ± 13 years). Amongst these patients, pathogenic/likely pathogenic variants were detected in LMNA (n = 7), DSP (n = 3), FLNC (n = 1) and PLN (n = 1). Of note, 6/12 (50%) had abnormal myocardial FDG uptake, including diffuse (entire myocardium) uptake in 2/6 (33%), focal (1–2 segments) uptake in 2/6 (33%) and patchy (3+ segments) in 2/6 (33%). Median myocardial standardized uptake value ratio was 2.1. Interestingly, LMNA-positive patients accounted for 3 out of 6 (50%) positive studies (diffuse uptake in 2 and focal uptake in 1). ConclusionAbnormal myocardial FDG uptake is common in genetic ACM patients undergoing cardiac FDG PET. This study further supports the role of myocardial inflammation in ACM. Further investigation is needed to determine role of FDG PET in diagnosis and management of ACM and investigate the role of inflammation in ACM.

Diagnostic values of delayed additional FDG PET/CT scan in the evaluation of cardiac sarcoidosis.

This study aimed to compare the contribution of 18F-fluorodepxyglucose (FDG) positron (PET)/ computed tomography (CT) acquisition of early and delayed scans in patients with cardiac sarcoidosis (CS). Twenty-three patients with CS (median age: 69years; 11 women) were retrospectively evaluated using dual-phase FDG PET/CT. All patients were instructed to consume a low-carbohydrate diet followed by fasting for 18h before FDG injection to reduce physiological myocardial uptake. PET/CT was acquired at 60min (early) and 100min (delayed) after FDG administration. Focal and focal on diffuse uptake on visual analysis was considered positive for CS. A semi-quantitative analysis was performed using the maximum standardized uptake value (SUVmax) of the cardiac lesion and the mean SUV (SUVmean) of the blood pool. Significant myocardial FDG uptake was observed in 21 patients (91.3%) in the early acquisition group and in 23 patients in the delayed scan group (100%). Compared to the early scan, the delayed scan showed a significantly higher SUVmax of the cardiac lesion [median, 4.0; IQR (interquartile range, 2.9 to 7.0) vs. 5.8 (IQR 3.7 to 10.1); P = 0.0030] and a significantly lower SUVmean of blood pool [median, 1.3 (IQR, 1.2 to 1.4) vs. 1.1 (IQR, 0.9 to 1.2); P < 0.0001]. Delayed FDG PET/CT acquisition improves detection accuracy in patients with CS compared to early scans with washout of the blood pool activity. Therefore, it can contribute to a more accurate assessment of CS.

Unusual Diffuse and Heterogeneous FDG Uptake in Appendicular Bone Marrow Space in a Patient with Acute Lymphoblastic Leukemia.

We describe a case of F-18-2-fluoro-2-deoxyglucose (FDG) uptake in the appendicular bones on a positron emission tomography/computed tomography (PET/CT) scan in a 20-year-old woman with a diagnosis of acute lymphoblastic leukemia. An FDG PET/CT was performed on this patient because of fever of unknown origin, revealing diffuse and heterogeneous FDG uptake in the bone marrow space of both humeri, femurs, and tibiae. The patient underwent magnetic resonance imaging, which demonstrated bone infarction with heterogeneous high, intermediate, and dark signal intensities on T1- and T2-weighted images in the same areas.

Non-invasive in vivo thrombus imaging in patients with ischaemic stroke or transient ischaemic attack

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Life Molecular Imaging provide reagents for GP1 production free of charge. Background and Purpose 18F-GP1 is a novel positron-emitting radiotracer that has high and specific binding affinity for the activated glycoprotein IIb/IIIa receptor, a key receptor in platelet activation and thrombus formation. Preliminary studies 18F-GP1 demonstrated excellent in vivo binding properties which enabled detection of intravascular thrombosis in a range of conditions including coronary thrombosis, left ventricular thrombus, pulmonary thromboembolism, and deep vein thrombosis. In a pilot proof-of-concept study, we aimed to determine its potential clinical application in establishing the role and origin of thrombus in stroke . Methods Autoradiography of 18F-GP1 uptake was performed on post-mortem samples of infarcted brain tissue following an acute ischaemic stroke and from control brain tissue without stroke. Eleven patients with recent ischaemic stroke (n=9) or transient ischaemic attack (n=2) underwent 18F-GP1 positron emission tomography and computed tomography angiography at median of 11 (absolute range 2–21) days from symptom onset. 18F-GP1 uptake (quantified by maximum target-to-background ratio, TBRmax) was assessed in the carotid arteries and brain. Results Ex vivo autoradiography of post-mortem infarcted brain tissue showed focal uptake corresponding to intraluminal thrombus within the culprit vessel and downstream microvasculature. There was also evidence of lower diffuse uptake within some of the infarcted brain tissue reflecting microthrombi within regions of reperfusion haemorrhage. In vivo 18F-GP1 uptake was identified in 9 of 11 patients: 3 in the carotid arteries only, 3 in the brain only and 3 in both the brain and carotid arteries. In those with carotid uptake, 3 participants had &amp;gt;50% stenosis and 3 had non-stenotic disease. One case had bilateral stenotic disease (&amp;gt;70%) but only the culprit carotid artery demonstrated 18F-GP1 uptake. The average uptake was higher in the culprit (median TBRmax 1.55 [interquartile range 1.26–1.82]) compared with the contralateral non-culprit carotid artery (TBRmax 1.22 [1.19–1.6]). In those with brain 18F-GP1 uptake (TBRmax 6.45 [4.89–7.65]), areas of acute infarction on computed tomography correlated with brain 18F-GP1 uptake in 6 cases. There was no brain 18F-GP1 uptake in the 7 cases without CT-defined acute cerebral infarction. Conclusions 18F-GP1 positron emission tomography and computed tomography angiography is a novel non-invasive method of identifying in vivo cerebrovascular thrombosis which holds major promise in understanding the role and origin of thrombosis in stroke.

Graves’ disease after exposure to the SARS-CoV-2 vaccine: a case report and review of the literature

BackgroundAutoimmune/inflammatory syndrome induced by adjuvants (ASIA) is characterized by immune system dysregulation after exposure to adjuvants, such as aluminum. Although cases of autoimmune thyroid diseases caused by ASIA have been reported, Graves' disease is one of the rarer diseases. There are some reports that vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause ASIA. Here, we describe a case of Graves’ disease following SARS-CoV-2 vaccination and a review of the literature.Case presentationA 41-year-old woman was admitted to our hospital because of palpitations and fatigue. Two weeks after receiving the second SARS-CoV-2 vaccine (BNT162b2, Coronavirus Modified Uridine messenger RNA (mRNA) Vaccine, Pfizer), she developed fatigue and gradually worsened. On admission, she exhibited thyrotoxicosis (thyroid-stimulating hormone (TSH) < 0.01 mIU/L (0.08–0.54), free triiodothyronine (FT3) 33.2 pmol/L (3.8–6.3), and free thyroxine (FT4) 72.1 pmol/L (11.6–19.3)) and palpitations associated with atrial fibrillation. TSH receptor antibody (TRAb) was positive (TRAb 5.0 IU/L (< 2.0)), and 99mTc scintigraphy showed diffuse uptake in the thyroid gland, suggesting that the thyrotoxicosis in this case was caused by Graves’ disease. Thiamazole was prescribed to correct her condition, and soon after this treatment was initiated, her symptoms and thyroid hormone levels were significantly reduced.ConclusionsThis case report reinforces the potential correlation between ASIA affecting the thyroid and SARS-CoV-2 mRNA vaccines. The clinical course suggests that it is essential to consider the possibility of developing ASIA, such as Graves' disease, after exposure to the SARS-CoV-2 vaccine.

17th International Conference on Malignant Lymphoma, Palazzo dei Congressi, Lugano, Switzerland, 13 - 17 June, 2023.

Introduction and Aim: Recently, in an ancillary study of FOLL12 trial (NCT02063685), total Metabolic Tumor Volume (tMTV) assessed before treatment has been demonstrated to be an independent predictor of PFS in patients receiving frontline immune chemotherapy (1). During the segmentation procedure, it has been observed that frequently spleen MTV (sMTV) heavily influenced the tMTV value, particularly in case of diffuse spleen uptake included in tMTV calculation. High tMTV could be a negative prognostic factor as it represents the tumor burden. On this basis, the aim of the current study was to evaluate the effect of the sMTV defined on baseline PET on tMTV calculation and its impact on outcome, particularly 5y-PFS (Progression Free Survival), in follicular lymphoma patients. Methods and Results: Overall, 690 patients with baseline PET were included in the analysis, 48% were older than 60 years, 89% had stage III-IV disease and 40% had a high-risk FLIPI-2 score. Overall, the 5y-PFS was 79% (95% CI, 76%–82%). Among 690 patients 469 (67.9%) did not have spleen involvement while 128 (18.5%) and 93 (13.4%) showed focal and diffuse spleen involvement, respectively. The 5y-PFS (95% CI) according the spleen status was 67% (62–72), 58% (48–67) and 61% (49–61) in patients without, with focal and with diffuse spleen involvement, respectively (p not significant). MTV calculation was performed with a threshold of 41% for segmentation. In the whole population of 690 patients, the tMTV threshold to categorized low and high tumor burden was 224 and 194 ml with and without sMTV, respectively. Assuming 200 ml as a tMTV threshold, only 16/693 pts (2.3%) changed from low to high tumor burden when the sMTV was included in the tMTV. Including sMTV in tMTV, with a threshold of 200 ml, the 5y-PFS in patients with low and high tMTV was 73% (95% CI: 67–78) and 58% (95% CI: 53–64), respectively, with a HR of 1.83 (p < 0.001). Excluding sMTV from tMTV, the 5y-PFS in patients with low and high tMTV was 72% (95% CI: 67–77) and 58% (95% CI: 52–64) with a HR of 1.80 (p < 0.001). In the two groups, HRs values for tMTV >200 ml showed negligible difference, independently from sMTV inclusion. Conclusion: These preliminary data of the FOLL12 trial showed that tMTV correlated with outcome in terms of PFS; on the contrary the metabolic spleen status defined in the baseline PET do not seem to show any prognostic added value, neither in case of focal nor in case of diffuse uptake. Finally, the inclusion/exclusion of the sMTV into the tMTV did not significantly change either the risk classification of the patients or the outcome in terms of PFS. Larger patients population are needed to confirm these data.

Potential clinical utility of 68Ga-DOTATATE PET/CT for detection and response assessment in cardiac sarcoidosis

BackgroundSomatostatin receptor is expressed in sarcoid granulomas, and preliminary clinical studies have shown that myocardial sarcoidosis can be identified on somatostatin receptor-targeted PET. We examined the potential clinical use of 68Ga-DOTATATE PET/CT for diagnosis and response assessment in cardiac sarcoidosis compared to 18F-FDG PET/CT. MethodsEleven cardiac sarcoidosis patients with 18F-FDG PET/CT were prospectively enrolled for cardiac 68Ga-DOTATATE PET/CT. The two PET/CT studies were interpreted independently and were compared for patient-level and segment-level concordance, as well as for the degree of radiotracer uptake. Follow-up 68Ga-DOTATATE PET/CT was performed in eight patients. ResultsPatient-level concordance was 91%: ten patients had multifocal DOTATATE uptake (active cardiac sarcoidosis) and one patient showed diffuse DOTATATE uptake. Segment-level agreement was 77.1% (Kappa 0.53 ± 0.07). The SUVmax-to-blood pool ratio was lower on 68Ga-DOTATATE PET/CT (3.2 ± 0.6 vs. 4.9 ± 1.5, P = 0.006 on paired t test). Follow-up 68Ga-DOTATATE PET/CT showed one case of complete response and one case of partial response, while 18F-FDG PET/CT showed four cases of response, including three with complete response. ConclusionCompared to 18F-FDG PET/CT, 68Ga-DOTATATE PET/CT can identify active cardiac sarcoidosis with high patient-level concordance, but with moderate segment-level concordance, low signal-to-background ratio, and underestimation of treatment response.

18F-FDG/PET-CT imaging findings after sternotomy

BackgroundThe clinical diagnosis of deep sternal wound infection (DSWI) is supported by imaging findings including 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT). To avoid misinterpretation due to normal post-surgery inflammation we assessed normal imaging findings in non-infected patients after sternotomy. MethodsThis is a prospective cohort study including non-infectious patients with sternotomy. All patients underwent 18F-FDG-PET/CT at either 5 weeks (group 1), 12 weeks (group 2) or 52 weeks (group 3) post-surgery. 18F-FDG uptake was scored visually in five categories and assessed quantitatively. ResultsA total of 44 patients were included. Sternal mean SUVmax was 7.34 (± 1.86), 5.22 (± 2.55) and 3.20 (± 1.80) in group 1, 2 and 3, respectively (p < 0.01). Sternal mean SUVmean was 3.84 (± 1.00), 2.69 (± 1.32) and 1.71 (± 0.98) in group 1, 2 and 3 (p < 0.01). All patients in group 1 had elevated uptake whereas group 2 and 3 showed 2/15 (13%) and 11/20 (55%) patients respectively with no elevated uptake. Group 3 still showed an elevated uptake pattern in in 9/20 (45%) and in 3/9 (33%) with a high-grade diffuse uptake pattern. ConclusionThis study shows significant lower sternal 18F-FDG at 55 weeks compared to 5 weeks post-sternotomy however elevated uptake patterns may persist.

Generalized ossificant myositis with intensive diffuse muscle uptake in whole body bone scan of a 13-year-old boy

Generalized ossificant myositis with intensive diffuse muscle uptake in whole body bone scan of a 13-year-old boy

Hepatic Superscan in Methotrexate-Associated Lymphoproliferative Disorder.

A 60-year-old man on methotrexate for treatment of adult-onset Still disease presented with acute onset of fever, pancytopenia, and deranged liver function. Besides FDG-avid lesions in spleen and skeleton, his 18F-FDG PET/CT study showed diffuse and intense uptake in the liver with significantly suppressed heart and brain activity (reminiscent of a hepatic superscan). Subsequent biopsy confirmed the diagnosis of methotrexate-associated lymphoproliferative disorder.