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1.
J Hypertens ; 40(6): 1179-1188, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35703880

RESUMO

OBJECTIVE: Adrenal vein sampling (AVS) is recommended to subtype primary aldosteronism, but it is technically challenging. We compared 11C-Metomidate-PET-computed tomography (PET-CT) and AVS for subtyping of primary aldosteronism. METHODS: Patients with confirmed primary aldosteronism underwent both AVS and 11C-Metomidate PET-CT (post-dexamethasone). All results were reviewed at a multidisciplinary meeting to decide on final subtype diagnosis. Primary outcome was accuracy of PET versus AVS to diagnosis of unilateral primary aldosteronism based on post-surgical biochemical cure. Secondary outcome was accuracy of both tests to final subtype diagnosis. RESULTS: All 25 patients recruited underwent PET and successful AVS (100%). Final diagnosis was unilateral in 22 patients, bilateral in two and indeterminate in one due to discordant lateralization. Twenty patients with unilateral primary aldosteronism underwent surgery, with 100% complete biochemical success, and 75% complete/partial clinical success. For the primary outcome, sensitivity of PET was 80% [95% confidence interval (95% CI): 56.3-94.3] and AVS was 75% (95% CI: 50.9-91.3). For the secondary outcome, sensitivity and specificity of PET was 81.9% (95% CI: 59.7-94.8) and 100% (95% CI: 15.8-100), and AVS was 68.2% (95% CI: 45.1-86.1) and 100% (95% CI: 15.8-100), respectively. Twelve out of 20 (60%) patients had both PET and AVS lateralization, four (20%) PET-only, three (15%) AVS-only, while one patient did not lateralize on PET or AVS. Post-surgery outcomes did not differ between patients identified by either test. CONCLUSION: In our pilot study, 11C-Metomidate PET-CT performed comparably to AVS, and this should be validated in larger studies. PET identified patients with unilateral primary aldosteronism missed on AVS, and these tests could be used together to identify more patients with unilateral primary aldosteronism. VIDEO ABSTRACT: http://links.lww.com/HJH/B918.


Assuntos
Hiperaldosteronismo , Glândulas Suprarrenais/irrigação sanguínea , Aldosterona , Radioisótopos de Carbono , Etomidato/análogos & derivados , Humanos , Hiperaldosteronismo/diagnóstico por imagem , Hiperaldosteronismo/cirurgia , Projetos Piloto , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Estudos Prospectivos , Estudos Retrospectivos
2.
Artigo em Inglês | MEDLINE | ID: mdl-35595985

RESUMO

Radioembolisation is an established transarterial therapy for hepatocellular carcinoma and liver metastasis. Success of radioembolisation depends on meticulous angiography and accurate dosimetry. Intra-procedure catheter-directed CT-angiography is commonly performed to improve the efficacy and safety of radioembolisation. This review article will (1) introduce the differences between cone beam CT and hybrid angiography-CT, and (2) describe the benefits of catheter-directed CT-angiography in radioembolisation from both an interventional radiology and nuclear medicine perspective.

3.
Clin Endocrinol (Oxf) ; 94(3): 504-512, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32886805

RESUMO

BACKGROUND: American Thyroid Association (ATA) low-intermediate-risk papillary thyroid cancer (PTC) patients without structural and biochemical evidence of disease on initial post-treatment evaluation have a low risk of recurrence. Studies have shown that with current ultrasound scans (US) and thyroglobulin assays, recurrences mostly occurred 2-8 years after initial therapy. The ATA recommends that neck US be done 6-12 months after surgery to establish patient's response to therapy, then periodically depending on risk of recurrence. The lack of clarity in recommendations on timing of follow-up US and fear of recurrence leads to frequent tests. OBJECTIVES: To evaluate the utility of routine neck US in ATA low-intermediate-risk PTC patients with no structural disease on neck US and non-stimulated thyroglobulin <1.0 ng/mL after initial therapy. METHODS: A retrospective study of 93 patients from Singapore, Saudi Arabia and Argentina with ATA low (n = 49) to intermediate (n = 44) risk PTC was conducted between 1998 and 2017. The outcome was to measure the frequency of identifying structural disease recurrence and non-actionable US abnormalities. RESULTS: Over a median follow-up of 5 years, five of the 93 patients (5.4%) developed structural neck recurrence on US at a median of 2.5 years after initial treatment. Indeterminate US abnormalities were detected in 19 of the 93 patients (20.4%) leading to additional tests, which did not detect significant disease. CONCLUSION: In ATA low-intermediate-risk PTC with no suspicious findings on neck US and a non-stimulated thyroglobulin of <1.0 ng/mL after initial therapy, frequent US is more likely to identify non-actionable abnormalities than clinically significant disease.


Assuntos
Neoplasias da Glândula Tireoide , Humanos , Recidiva Local de Neoplasia/diagnóstico por imagem , Estudos Retrospectivos , Câncer Papilífero da Tireoide/diagnóstico por imagem , Câncer Papilífero da Tireoide/cirurgia , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia
4.
Singapore Med J ; 62(9): 486-491, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-32227795

RESUMO

Radiation thyroiditis resulting from radioactive iodine-131 treatment for Graves' disease is an uncommon complication. Although a majority of patients are asymptomatic or manifest mild symptoms that can be managed conservatively, published literature describing severe radiation thyroiditis resulting in significant morbidity is lacking. We herein report on six patients with severe radiation thyroiditis that resulted in hospitalisation, including an unusual complication of myopericarditis.


Assuntos
Doença de Graves , Neoplasias da Glândula Tireoide , Tireoidite , Diagnóstico Diferencial , Doença de Graves/radioterapia , Humanos , Radioisótopos do Iodo/efeitos adversos , Neoplasias da Glândula Tireoide/diagnóstico , Tireoidite/complicações , Tireoidite/diagnóstico
5.
Semin Nucl Med ; 50(5): 419-433, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32768006

RESUMO

Liver cancer is one of the top leading causes of mortality worldwide. Conventional imaging using contrast enhanced CT and MRI are currently the mainstay of oncologic imaging of the liver for the diagnosis and management of cancer. In the past two decades, especially since the advent of hybrid imaging in the form of PET/CT and SPECT/CT, molecular imaging has been increasingly utilized for oncologic imaging and the variety of radionuclide probes for imaging liver cancers have been expanding. Beyond the usual workhorse of FDG as an oncologic tracer, there is a growing body of evidence showing that radiolabeled choline tracers, C-11 acetate and other new novel tracers may have increasing roles to play for the imaging of liver tumors. On the therapy front, there have also been advances in recent times in terms of targeted therapies for both primary and secondary liver malignancies, particularly with transarterial radioembolization. The concept of theranostics can be applied to transarterial radioembolization by utilizing a pretreatment planning scan, such as Tc-99m macroaggregated albumin scintigraphy, coupled with post treatment imaging. Radiation dose planning by personalized dosimetric calculations to the liver tumors is also being advocated. This article explores the general trends in the field of nuclear medicine for the imaging and treatment of liver cancer above and beyond routine diagnosis and management.


Assuntos
Neoplasias Hepáticas/diagnóstico por imagem , Imagem Molecular , Humanos , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/terapia
7.
Nucl Med Commun ; 41(7): 618-628, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32282629

RESUMO

OBJECTIVE: Metastatic castration-resistant prostate cancers are aggressive tumors with poor prognosis. Prostate-specific membrane antigen-targeted radionuclide therapy is a potential treatment for these patients. Here, we report our initial experience in Singapore. METHODS: Twenty men (median age 70) with progressive disease were prospectively recruited. Prostate-specific membrane antigen and fluorodeoxyglucose-PET/computed tomography were performed to confirm high prostate-specific membrane antigen-expression. Up to four cycles of lutetium-prostate-specific membrane antigen-I&T at 6-8 weekly intervals were administered. Patients were restaged 3 months following treatment. Primary endpoints were prostate-specific antigen decline ≥50% and treatment-related toxicity. Additional endpoints included radiological and clinical response as well as progression-free survival and overall survival from first cycle. RESULTS: Sixty-seven cycles were administered (median 4 cycles per patient, mean 6.5 GBq per cycle). Sixty five percent had ≥1 line of prior chemotherapy, 90% abiraterone, enzalutamide or both, and 30% radium-223 radionuclide therapy. All had bone metastases and 35% had visceral metastases. Prostate-specific antigen decline ≥50% was achieved in 50%. Grade 3-4 hematotoxicity was seen in up to 15%. Grade 3-4 non-hematotoxicity was not observed. Eleven patients had restaging scans 3 months post-treatment (5 = partial response, 6 = progressive disease). Fifty-seven percent (4/7) with bone pain had pain improvement. Median progression-free survival was 5.9 months and median overall survival 13.1 months. Patients with prostate-specific antigen decline ≥50% had longer progression-free survival and overall survival. CONCLUSION: Lutetium-prostate-specific membrane antigen-I&T therapy is effective with tolerable side effects in our local setting. Prostate-specific antigen decline ≥50% is associated with longer progression-free survival and overall survival.


Assuntos
Calicreínas/metabolismo , Lutécio/uso terapêutico , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Radioisótopos/uso terapêutico , Adulto , Idoso , Humanos , Lutécio/efeitos adversos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Projetos Piloto , Estudos Prospectivos , Radioisótopos/efeitos adversos , Análise de Sobrevida , Resultado do Tratamento
8.
Nucl Med Mol Imaging ; 53(2): 96-101, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31057680

RESUMO

The concept of theranostics, where individual patient-level biological information is used to choose the optimal therapy for that individual, has become more popular in the modern era of 'personalised' medicine. With the growth of theranostics, nuclear medicine as a specialty is uniquely poised to grow along with the ever-increasing number of concepts combining imaging and therapy. This special report summarises the status and growth of Theranostic Nuclear Medicine in Singapore. We will cover our experience with the use of radioiodine, radioiodinated metaiodobenzylguanidine, peptide receptor radionuclide therapy, prostate specific membrane antigen radioligand therapy, radium-223 and yttrium-90 selective internal radiation therapy. We also include a section on our radiopharmacy laboratory, crucial to our implementation of theranostic principles. Radionuclide theranostics has seen tremendous growth and we hope to be able to grow alongside to continue to serve the patients in Singapore and in the region.

10.
Clin Imaging ; 40(3): 486-91, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27133692

RESUMO

OBJECTIVES: Prostate carcinoma is a major health problem, and routine imaging shows only modest results in detecting and restaging clinically localized prostate cancer recurrence. Recent studies have shown promise of radiolabeled analogues of choline for positron emission tomography (PET) scans in patients of biochemical recurrence and that sequentially incremental Fluorocholine (FCH) uptake is associated with malignancy, whereas decreasing tracer activity suggests a benign aetiology. However, this pattern of tracer uptake has not been fully validated, and no standardized (18)F-Fluorocholine ((18)F-FCH) scan protocol is in place yet. This study aimed to better define the role of dual-phase (18)F-FCH PET/computed tomography (CT) imaging using retrospective masked reading focusing on detection of locoregional recurrence/metastasis in patients with biochemical failure after definitive local primary treatment. METHODS: A total of 32 subjects were enrolled during the period 04/2010 to 05/2014 with histologically proven prostate cancer that was treated with curative intent and had biochemical recurrence. Early scans and delayed imaging of the pelvis were graded separately by blinded readers. Final evaluation using the combination of information from dual-phase studies as a "summation scan" was also performed. Maximum standardized uptake value was computed using regions of interest constructed over focal hyperactivity. Calculations were performed using Statistical Product and Service Solutions, Version 20 for Windows. A composite reference consisting of histopathology, correlation with other imaging, or serum prostate specific antigen (PSA) trend with clinical follow-up of at least 6months was used to determine the true disease status of the patient. RESULTS: Early-phase pelvis imaging sensitivity and specificity were calculated to be 73.1% and 90.9%, respectively. Late-phase pelvis imaging sensitivity and specificity were 80.8% and 100%, respectively. Summation scan sensitivity and specificity were 76.9% and 100%, respectively. The odds ratio of having recurrent disease with an uptrend of SUVmax on dual-phase imaging was 33.3. The optimal cutoff value of PSA was 1.85ng/mL with 80% sensitivity and 62.5% specificity. CONCLUSIONS: Single late-phase FCH PET/CT imaging is a reliable scan modality which can detect sites of disease at low levels of PSA which still fulfil the criteria of biochemical recurrence. This will allow clinicians to identify sites for potential biopsy or start locoregional treatment.


Assuntos
Colina/análogos & derivados , Recidiva Local de Neoplasia/diagnóstico , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias da Próstata/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Colina/farmacologia , Radioisótopos de Flúor , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos
11.
Ann Nucl Med ; 30(3): 255-61, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26692012

RESUMO

OBJECTIVE: Activity planning for (90)Y radioembolization aims to maximize the effect of the treatment while keeping toxicity acceptably low. Our aim was to describe the amount of residual activity in post-treatment v-vials and tubing and analyze the possible factors affecting it (total activity administered, number of split activity injection(s), previous treatments, administration artery and microcatheter size), as these may influence dosimetric planning and treatment. METHODS: This was a retrospective review using case records of patients who received (90)Y-radioembolization for hepatic tumors at a single tertiary center. From August 2013 to September 2015, seventy-seven out of one hundred and fifty patients who received radioembolization with (90)Y resin microspheres due to inoperable Hepatocellular Carcinoma (HCC) or liver metastases were included. The rest were mainly excluded due to incomplete data sets. The number of split activities (injections) for the radioembolization could be: one single injection, two or three. The remnant activity in post-treatment v-vials and tubing were measured for every patient. The administration arteries evaluated were: proper hepatic artery (PHA), right hepatic artery (RHA), middle hepatic artery (MHA), left hepatic artery (LHA) and small caliber branch arteries. The sizes of the microcatheters (2.2 or 2.7 Fr) used to administer the dose were also evaluated. RESULTS: In total, 77 out of 150 patients were included in the final analysis. There were 59 men of median age 64.0 years old. The total median dose loss was 0.10 GBq. The total dose loss increased 0.244 GBq [95 % CI = (0.169, 0.318)] when three split activities were given compared to single activity injection. Activity loss for each injection increased 0.0297 GBq [95 % CI = (0.0151, 0.0443)] for every 1.0 GBq increase of split activity injection. There were no significant statistical differences in the rest of patient characteristics. CONCLUSIONS: There is significant loss of activity observed during radioembolization, which can have a major dosimetric impact. The total administered activity and the number of split injections during radioembolization are the main influencing factors. Further prospective studies as well as measures of clinical outcome are warranted.


Assuntos
Embolização Terapêutica/métodos , Neoplasias Hepáticas/terapia , Microesferas , Resinas Sintéticas/química , Radioisótopos de Ítrio/química , Radioisótopos de Ítrio/uso terapêutico , Idoso , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Radiometria , Estudos Retrospectivos
12.
J Breast Cancer ; 17(3): 291-4, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25320629

RESUMO

After mastectomy and axillary node dissection, chylous leakage is rare. However, considerable anatomical variation in the termination of the thoracic duct has been reported. Hence, during breast surgery, injury to the lateral terminating branch is not unlikely and might lead to retrograde chyle leak. Herein, we describe a patient who had a chylous leakage at her wound site after a left simple mastectomy and axillary node dissection and for whom lymphoscintigraphy with Tc-99m albumin nanocolloid was performed. In this case, additional hybrid single-photon emission computed tomography/computed tomography study was done, and has helped with the accurate identification of the chyle leakage site, thus aiding in surgical management.

13.
Can J Cardiol ; 30(8): 956.e15-7, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24951253

RESUMO

A man presented with shortness of breath, and a globular heart was seen on a chest radiograph. An echocardiogram showed masses at the atrioventricular grooves. Computed tomography (CT) coronary angiography and fluorine-18 ((18)F) fluorodeoxyglucose positron emission tomography (FDG-PET)/CT confirmed coronary aneurysms with hypermetabolic perivascular masses at the coronary arteries and right internal iliac artery. Histologic features were highly suspicious for IgG4-related disease (IgG4-RD). IgG4-RD is a recently recognized fibroinflammatory condition, and FDG-PET/CT can provide information about the disease pattern, which may suggest IgG4-RD, as well as the optimal biopsy site.


Assuntos
Arterite/diagnóstico , Doenças Autoimunes/diagnóstico , Vasos Coronários/patologia , Imunoglobulina G/sangue , Aneurisma Coronário/diagnóstico , Angiografia Coronária , Ecocardiografia , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada por Raios X
14.
Semin Musculoskelet Radiol ; 18(2): 194-202, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24715450

RESUMO

This article provides a brief overview of the current state of hybrid single-photon emission computed tomography/computer tomography (SPECT/CT) imaging in musculoskeletal infections. SPECT/CT imaging, compared with conventional planar study and SPECT alone, provides improved anatomic localization of infection and more accurate delineation of the extent of infection. This article emphasizes three clinical aspects where SPECT/CT is found to be most useful: differentiating between soft tissue and bone infections, assessing suspected infected sites with underlying structural bone alterations, and defining infective focus when complex anatomy is involved. The accurate assessment of site of infection is vital for selecting the most appropriate therapeutic strategy. Other advantages of SPECT/CT imaging such as reducing the inconvenience of combination planar studies, providing additional CT information, and increasing interobserver agreement are also discussed.


Assuntos
Infecções/diagnóstico , Doenças Musculoesqueléticas/diagnóstico , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodos , Doenças Ósseas/diagnóstico , Criança , Doenças do Pé/diagnóstico , Radioisótopos de Gálio , Humanos , Radioisótopos de Índio , Complicações Pós-Operatórias/diagnóstico , Infecções dos Tecidos Moles/diagnóstico , Doenças da Coluna Vertebral/diagnóstico , Tecnécio Tc 99m Exametazima , Medronato de Tecnécio Tc 99m , Ferimentos e Lesões/complicações
15.
Clin Nucl Med ; 39(7): 643-5, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24662655

RESUMO

We describe a rare case of myocardial plasmacytoma staged and followed up with FDG PET/CT. A 72-year-old man was incidentally identified with a right ventricular apical mass, which was pathologically confirmed to be a plasmacytoma. A pre-treatment FDG PET/CT scan subsequently showed lesions not only in the right ventricle but also in the bones and mediastinal lymph nodes, which led to the change in treatment plan. Post-therapy PET scan revealed good response. This case demonstrates the value of FDG PET/CT in accurately staging unusually presented plasmacytoma and in monitoring response to treatment.


Assuntos
Fluordesoxiglucose F18 , Miocárdio/patologia , Plasmocitoma/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Idoso , Humanos , Masculino
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