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Evaluation of 177Lu-Dotatate treatment in patients with metastatic neuroendocrine tumors and prognostic factors

The lack of a standardized cut-off value in the quantitative method and an inter-observer disagreement in the evaluation of the semiquantitative score in 99mTc-DPD scintigraphy leaves several patients with cardiac amyloidosis (CA) undiagnosed (grade 1 and H/CL: 1–1.49). This study aims to increase diagnostic productivity of 99mTc-DPD scintigraphy in CA. This is a retrospective study of 170 patients with suspicion of CA. A total of 81 (47.6%) were classified as transthyretin CA (TTR-CA) and 9 (5.3%) as light-chain CA (LC-CA) applying the visual score. An enhanced quantitative method and cut-off point were attempted to reclassify inconclusive patients and reduce inter-observer variability. Applying the proposed quantitative method, of the 19 patients with grade 1 uptake, 2 became grade 0 (none-CA), 2 were reclassified as grade 3 (TTR-CA), and 2 were regrouped as grade 2 (1 TTR-CA and 1 LC-CA). Adjusting the quantitative method’s cut-off value to 1.3, four patients previously inconclusive were reclassified as TTR-CA, the diagnosis was confirmed in 3 and rejected in 1. When a 1.3 threshold is compared to 1.5, the sensitivity increases to 94% without reducing its specificity. The quantitative method improves the visual interpretation, reclassifying doubtful cases. The optimization of the cut-off value from 1.5 to 1.3 reclassifies a higher percentage of patients as TTR-CA with a higher sensitivity without reducing its specificity.

Introduction: The early diagnosis of infective endocarditis (IE) is a medical challenge and a multidisciplinary approach is essential to improve its frequently fatal prognosis. Our goal was to evaluate the usefulness of [18F]2-fluoro-2-deoxy-d-glucose positron emission tomography (18F-FDG PET) in the diagnosis of this disease. Materials and Methods: We prospectively assessed 43 patients (five female and 38 male) with clinical suspicion of IE between 2014 and 2017. All patients underwent transesophageal echocardiography (TEE) and an 18F-FDG PET scan, and the results were compared. A positive PET finding was defined as increased FDG uptake on cardiac valves or intracardiac devices. Results: Out of 43 patients with suspected IE, the diagnosis was confirmed in 30 cases (79.7%). 18F-FDG PET was positive in 24 patients, with 19 showing FDG uptake on cardiac valves (two native and 17 prosthetic) and five on cardiac devices, being concordant with echocardiographic findings in 11 cases. 18F-FDG PET sensitivity was 80%, specificity 92%, positive predictive value (PPV) 96% and negative predictive value (NPV) 66%. Echocardiography presented sensitivity, specificity, PPV and NPV of 36%, 84%, 84% and 36%, respectively. Conclusions: 18F-FDG PET proved to be a sensitive technique with a high diagnostic value in patients with prosthetic valves and intracardiac devices and suspected IE. Its utility decreased dramatically in patients with suspected IE on native valves, in which TEE presented higher sensitivity and thus better diagnostic value. Resumo: Introdução: O diagnóstico precoce de endocardite infecciosa (EI) é um desafio médico. Portanto, uma abordagem multidisciplinar é essencial para melhorar o prognóstico desta patologia, muitas vezes fatal. O nosso objetivo foi avaliar a utilidade da tomografia por emissão de pósitrons [18F] 2-fluoro-2-desoxi-D-glicose (18F-FDG-PET) no diagnóstico desta doença. Materiais e métodos: De forma prospetiva, avaliámos 43 doentes (5 do sexo feminino e 38 do masculino) clinicamente suspeitos de EI entre 2014-2017. Todos os doentes foram submetidos a um ecocardiograma transesofágico (ETE) e uma PET 18F-FDG, os resultados foram posteriormente comparados. Um critério PET positivo foi definido como um aumento na captação de FDG nas válvulas cardíacas ou nos dispositivos intracardíacos. Resultados: Dos 43 doentes com suspeita de EI, o diagnóstico foi confirmado em 30 casos (79,7%). O 18F-FDG-PET foi positivo em 24 doentes, dos quais 19 demonstraram captação de FDG nas válvulas cardíacas (2 nativas e 17 protésicas) e cinco nos dispositivos cardíacos, concordando com os achados ecocardiográficos em 11 casos. A sensibilidade de 18F-FDG-PET (S) foi de 80%, especificidade (P) de 92%, valor preditivo positivo (VPP) de 96% e valor preditivo negativo (VPN) de 66%. A ecocardiografia apresentou valores de S, P, PPV e VPN de 36%, 84%, 84% e 36%, respetivamente. Conclusões: O 18F-FDG-PET demonstrou ser uma técnica sensível com alto valor diagnóstico em doentes com suspeita de EI com próteses valvulares e dispositivos intracardíacos. A utilidade desta técnica diminui drasticamente em doentes com suspeita de EI nas válvulas nativas, nas quais a ETE apresentou maior sensibilidade e, portanto, melhor valor diagnóstico. Keywords: Infective endocarditis, Positron emission tomography, 18-Fluoro-2-deoxy-d-glucose, Transesophageal echocardiography, Palavras-chave: Endocardite infecciosa (EI), Tomografia por emissão de pósitrões (18F-FDG-PET), Ecocardiograma transesofágico (ETE)

Background Neuroendocrine tumours (NET) conform a rare type of neoplasm, mostly located in the gastrointestinal tract. They are slow-growing tumours, so at the time of the diagnosis, most patients present with metastatic lesions, mainly in the liver. The myocardium is a rare and important organ for metastasis, in which 68Ga-Dotatate positron emission tomography-computed tomography (PET/CT) shows a high diagnostic sensitivity for its detection, contrary to carcinoid valve disease, where anatomic imaging plays a key role, especially the echocardiogram. Case summary A 60-year-old man diagnosed with metastatic progressive ileal NET, who underwent a 68Ga-Dotatate PET/CT prior 177Lu-Dotatate therapy, showed a metastatic lesion in the left ventricle that was undetected in previous studies, such as an Octreoscan® and CT. A transthoracic echocardiogram was performed revealing the existence of a second cardiac lesion, a tricuspid valve carcinoid disease. A cardiac magnetic resonance showed no late gadolinium enhancement. Discussion The 68Ga-Dotatate PET/CT is currently considered the gold standard for assessment and follow-up of NET, including those with rare sites of metastasis such as cardiac infiltration. In this case, it stimulated the persue of possible cardiac involvement, detecting the coexistence of two types of lesions (cardiac metastasis and carcinoid valve disease). Of these, carcinoid valvulopathy develops in 50% of NET cases, while cardiac metastasis (CM) is less frequent (only 5%).

371 Background: Inflammation plays a key role in the pathophysiology of many diseases, including cancer. Systemic inflammatory factors have been validated as indicators of ongoing systemic inflammation that could be predictive markers of poor prognosis for oncological outcomes. However, it is unknown the prognostic impact of systemic inflammation markers in patients with GEP-NETs treated with PRRT. Methods: We conducted an observational, retrospective, multicentric study of 40 patients with GEP-NET treated with PRRT belonging to GGNET (Galician Research Group on Neuroendocrine Tumors) network at Nuclear Medicine Department of Santiago de Compostela University Hospital (Spain). The systemic inflammatory markers were calculated as follows: NLR = neutrophil count/lymphocyte count, PLR = platelet count/lymphocyte count, MLR= monocyte count/lymphocyte count, ALB= albumin levels and dNLR = neutrophil count/ (leucocytes count – neutrophils count). For the calculation of the different ratios, baseline analysis and after the second dose were used. The cut-off values were determined as the median of each values, correlating them with progression-free survival (PFS). Results: Data from 40 patients (pts) treated between 2016 and 2020 were recorded. Median age was 63.5 years (range 41-85) and 55% were male. Baseline ECOG PS 0/1/2 was 15 (37.5%)/16 (40%)/9 (22.5%). Tumor location was intestinal 26 pts (65%), pancreas 11 pts (27.5%) and unknown origin 3 pts (7.5%). 15 pts (37.5%) were functioning. Tumor grade G1/G2/G3 were 17 pts (42.5%)/ 20 pts (50%)/ 3 pts (7.5%), and Ki 67 20%/unknown were 11 pts (27.5%)/ 21 pts (52.5%)/ 3 pts (7.5%)/ 5 pts (12.5%), respectively. The most frequent site of metastasis was liver 32 pts (80%), lymph nodes 19 pts (47.5%), peritoneum 11 pts (27.5%) and bone 10 pts (25%). Surgery: 22 pts (55%) primary tumor surgery and 8 pts (20%) metastasectomy. Previous systemic treatments included somatostatin analogs (SSA) 40 pts (100%), everolimus 26 pts (65%) and sunitnib 11 pts (27.5%), others 7 pts (17.5%). The baseline cutoff-values for NLR was 2.61, for PLR 110.14, for MLR 0.31, for ALB 4.2. and for dNLR 1.71. The cutoff-values after the 2nd dose for NLR was 2.3, for PLR 2.15, for MLR 0.3, for ALB 4.2 and for dNLR 1.48. With a median follow up of 21 months, 14 pts (35%) had died. Median PFS was 27.2 m (95% CI 16.0-38.4m) and OS was not reached (NR). Pts with baseline higher NLR (>2.61 vs. 1.71 vs.