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1.
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.

2.
Nanomaterials (Basel) ; 12(4)2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35214911

RESUMO

Nuclear imaging is a powerful non-invasive imaging technique that is rapidly developing in medical theranostics. Nuclear imaging requires radiolabeling isotopes for non-invasive imaging through the radioactive decay emission of the radionuclide. Nuclear imaging probes, commonly known as radiotracers, are radioisotope-labeled small molecules. Nanomaterials have shown potential as nuclear imaging probes for theranostic applications. By modifying the surface of nanomaterials, multifunctional radio-labeled nanomaterials can be obtained for in vivo biodistribution and targeting in initial animal imaging studies. Various surface modification strategies have been developed, and targeting moieties have been attached to the nanomaterials to render biocompatibility and enable specific targeting. Through integration of complementary imaging probes to a single nanoparticulate, multimodal molecular imaging can be performed as images with high sensitivity, resolution, and specificity. In this review, nanomaterial nuclear imaging probes including inorganic nanomaterials such as quantum dots (QDs), organic nanomaterials such as liposomes, and exosomes are summarized. These new developments in nanomaterials are expected to introduce a paradigm shift in nuclear imaging, thereby creating new opportunities for theranostic medical imaging tools.

3.
Drug Discov Today ; 27(1): 280-291, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34332093

RESUMO

Positron emission tomography (PET) is an extensively used nuclear functional imaging technique, especially for central nervous system (CNS) and oncological disorders. Currently, drug development is a lengthy and costly pursuit. Imaging with PET radiotracers could be an effective way to hasten drug discovery and advancement, because it facilitates the monitoring of key facets, such as receptor occupancy quantification, drug biodistribution, pharmacokinetic (PK) analyses, validation of target engagement, treatment monitoring, and measurement of neurotransmitter concentrations. These parameters demand careful analyses for the robust appraisal of newly formulated drugs during preclinical and clinical trials. In this review, we discuss the usage of PET imaging in radiopharmaceutical development; drug development approaches with PET imaging; and PET developments in oncological and cardiac drug discovery.


Assuntos
Desenvolvimento de Medicamentos/métodos , Descoberta de Drogas/métodos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacologia , Antineoplásicos/farmacologia , Fármacos Cardiovasculares/farmacologia , Monitoramento de Medicamentos/métodos , Humanos , Traçadores Radioativos
4.
Front Genet ; 12: 721832, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34512731

RESUMO

BACKGROUND: The standard of care for thyroid cancer management is thyroidectomy and adjuvant radioactive iodine (RAI). There is a paucity of clinical tool that quantifies residual thyroid volume reliably for precise adjuvant RAI dosing. Serum thyroglobulin (TG), tumour marker for thyroid cancer, takes 4 weeks for complete clearance due to its long half-life, and might be undetectable in 12% of structural disease patients. It detects recurrence with a sensitivity of 19-40%, mainly attributed to issue of TG antibody interference with TG immunometric assay. We hypothesise that the quantity of thyroid-specific cell-free RNA (cfRNA) is indicative of amount of thyroid tissues, and that during thyroid surgery, cfRNA levels decrease accordingly. METHODS: We identified 11 biologically significant and highly expressed thyroid-specific targets from Human Protein Atlas and literature. To assess for a fall in thyroid-specific cfRNA level, we recruited 16 patients undergoing thyroid surgery or RAI for malignant or benign thyroid disease, and tracked longitudinal trend of cfRNA. To assess the utility of cfRNA in detecting metastatic thyroid cancer, cfRNA of 11 patients at intermediate to high risk of recurrence was measured during surveillance and at time of clinical recurrence. RESULTS: The multiplex assay was capable of amplifying and quantifying multiple thyroid-specific genes in a single reaction. The selected targets were amplified successfully from RNA extracted directly from the thyroid (positive control), indicating that they were highly expressed within thyroid tissue. These cfRNAs were present in plasma, in amounts quantifiable using qRT-PCR. Four cfRNA transcripts (TPO, GFRA2, IVD, TG) fell post-treatment in more than 50% of cohort. The thyroid peroxidase (TPO) cfRNA fell post-therapy in 63% of cohort by 80%, as early as 1 day post-treatment, supporting the potential role as early indicator of remnant thyroid tissue volume. We demonstrated the clinical relevance of circulating TPO cfRNA by tracking temporal changes in setting of peri-treatment, recurrence, and TG Ab positive state. CONCLUSION: Using a multiplex pre-amplification approach, the TPO cfRNA was a potential biomarker that can track residual thyroid mass. It can be further optimised for quantification of thyroid volume to guide RAI doses and for detection of thyroid cancer recurrence.

5.
Liver Cancer ; 10(3): 224-239, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34239809

RESUMO

INTRODUCTION: Real-world management of patients with hepatocellular carcinoma (HCC) is crucially challenging in the current rapidly evolving clinical environment which includes the need for respecting patient preferences and autonomy. In this context, regional/national treatment guidelines nuanced to local demographics have increasing importance in guiding disease management. We report here real-world data on clinical outcomes in HCC from a validation of the Consensus Guidelines for HCC at the National Cancer Centre Singapore (NCCS). METHOD: We evaluated the NCCS guidelines using prospectively collected real-world data, comparing the efficacy of treatment received using overall survival (OS) and progression-free survival (PFS). Treatment outcomes were also independently evaluated against 2 external sets of guidelines, the Barcelona Clinic Liver Cancer (BCLC) and Hong Kong Liver Cancer (HKLC). RESULTS: Overall treatment compliance to the NCCS guidelines was 79.2%. Superior median OS was observed in patients receiving treatment compliant with NCCS guidelines for early (nonestimable vs. 23.5 months p < 0.0001), locally advanced (28.1 vs. 22.2 months p = 0.0216) and locally advanced with macrovascular invasion (10.3 vs. 3.3 months p = 0.0013) but not for metastatic HCC (8.1 vs. 6.8 months p = 0.6300), but PFS was similar. Better clinical outcomes were seen in BCLC C patients who received treatment compliant with NCCS guidelines than in patients with treatment only allowed by BCLC guidelines (median OS 14.2 vs. 7.4 months p = 0.0002; median PFS 6.1 vs. 4.0 months p = 0.0286). Clinical outcomes were, however, similar for patients across all HKLC stages receiving NCCS-recommended treatment regardless of whether their treatment was allowed by HKLC. CONCLUSION: The high overall compliance rate and satisfactory clinical outcomes of patients managed according to the NCCS guidelines confirm its validity. This validation using real-world data considers patient and treating clinician preferences, thus providing a realistic analysis of the usefulness of the NCCS guidelines when applied in the clinics.

6.
Ann Nucl Med ; 35(5): 557-568, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33683545

RESUMO

OBJECTIVE: Natural killer T-cell lymphoma (NKTCL) is an aggressive type of non-Hodgkin's lymphoma. While FDG-PET/CT imaging has been increasingly utilized for disease assessment, its prognostic value and potential utility in NKTCL patient stratification remain controversial. We aim to investigate the prognostic utility of FDG-PET/CT and its role in complementing clinical indices. METHODS: We conducted a retrospective review of 72 patients from a tertiary National Cancer Centre with biopsy-proven NKTCL and available FDG-PET/CT data (either baseline, end of treatment or both). Survival analysis was performed using the Kaplan-Meier method and multivariable Cox proportional regression. RESULTS: High initial SUVmax was significantly associated with advanced Ann-Arbor stage (p = 0.0352), elevated LDH levels (p = 0.0059) and plasma EBV DNA detection (p = 0.0278). SUVmax correlated with worse progression-free survival (PFS) (HR 3.68, 95% CI 1.56-8.69, p = 0.0030) and a trend toward worse overall survival (OS) (HR 2.06, 95% CI 0.95-4.45, p = 0.0676). End of treatment Deauville scores of 4-5, as compared to scores of 1-3, was associated with worse PFS (HR 2.72, 95% CI 1.04-7.12, p = 0.0419). Notably, while all patients with scores of 5 developed progressive disease, only 2 of 5 patients with scores of 4 eventually relapsed. Clinical indices (NABS score) were still able to stratify survival outcomes regardless of end-of-treatment Deauville scores. CONCLUSIONS: A Deauville score of 5 is more diagnostic of true disease progression than a score of 4, and NABS score may be used in patients who achieve Deauville scores of 1-3 for further risk stratification. A higher SUVmax at baseline portends a worse prognosis in NKTCL.


Assuntos
Linfoma Extranodal de Células T-NK/diagnóstico , Adulto , Idoso , Feminino , Humanos , Linfoma Extranodal de Células T-NK/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida
7.
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
8.
Eur Radiol ; 31(1): 468-474, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32780206

RESUMO

The coronavirus 2019 (COVID-19) outbreak poses a serious public health risk. To date, the disease has affected almost all countries in the world. The enormous scale of the outbreak and the relative lack of knowledge and information regarding a new virus, as well as the unpredictability of events, make it challenging for leadership teams to respond. This paper shares how we have reconfigured our radiology leadership team into a smaller disease outbreak task force (DOTF) to respond and coordinate all related efforts during this ongoing COVID-19 pandemic. The DOTF format is modelled after the military with domain groups looking at manpower, intelligence, operations, and logistics matters on a daily basis so that timely decisions can be made and action plans executed promptly. In managing the DOTF, discipline, flexibility, and teamwork are key principles, and these are built upon a strong foundation of focus on infection prevention and control, and patient and staff safety as well as staff well-being. The DOTF has positioned us well to confront the many challenges to date. We believe it will also help us navigate the complex issues that will arise with future surges in cases and in formulating strategies to manage exit from the present and future lockdowns. KEY POINTS: • In a pandemic, regular and directed meetings by a smaller leadership core group are required, for prompt decision making and execution of action plans. • The military format, with domain groups to look at manpower, intelligence, operations, and logistics matters, is useful in managing a pandemic. • Discipline, flexibility, and teamwork with strong focus on infection prevention and control, and patient and staff safety as well as staff well-being are key principles for leadership teams managing a pandemic.


Assuntos
COVID-19/terapia , Controle de Infecções , Liderança , Serviço Hospitalar de Radiologia/organização & administração , Centros de Atenção Terciária/organização & administração , COVID-19/diagnóstico por imagem , COVID-19/transmissão , Tomada de Decisão Clínica , Infecção Hospitalar/prevenção & controle , Humanos , Pandemias , Administração de Recursos Humanos em Hospitais , SARS-CoV-2 , Singapura/epidemiologia
9.
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
12.
Eur J Nucl Med Mol Imaging ; 47(7): 1645-1648, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32232520

RESUMO

PURPOSE: The aim of this short communication is to outline our experience in policies and processes of a nuclear medicine service during the COVID-19 outbreak in Singapore. METHODS: We describe the key considerations of policies and processes that have been implemented in our nuclear medicine service since the first case of COVID-19 was confirmed in Singapore General Hospital on 23 January 2020, up to the present time. RESULTS: Infection control, screening of patients and visitors, segregation of risk groups, segregation of staff and service continuity plans, communication and staff welfare, using electronic platforms for multi-disciplinary meetings and tele-reporting are discussed. CONCLUSION: Since our hospital received the first patient with COVID-19 in Singapore, our centre has managed 16 COVID-19 cases to date. There has not been any healthcare worker in our institution who has contracted COVID-19 through patient contact. We have highlighted for discussion some of the policies and processes to prepare a nuclear medicine service for the COVID-19 threat.


Assuntos
Infecções por Coronavirus/epidemiologia , Surtos de Doenças , Medicina Nuclear , Pneumonia Viral/epidemiologia , COVID-19 , Comunicação , Infecções por Coronavirus/prevenção & controle , Humanos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Relatório de Pesquisa , Risco , Segurança
13.
Acta Biomater ; 110: 15-36, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32335310

RESUMO

Gd3+-based contrast agents have been extensively used for signal enhancement of T1-weighted magnetic resonance imaging (MRI) due to the large magnetic moment and long electron spin relaxation time of the paramagnetic Gd3+ ion. The key requisites for the development of Gd3+-based contrast agents are their relaxivities and stabilities which can be achieved by chemical modifications. These modifications include coordinating Gd3+ with a chelator such as diethylenetriamine pentaacetic acid (DTPA) or 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), encapsulating Gd3+ in nanoparticles, conjugation to biomacromolecules such as polymer micelles and liposomes, or non-covalent binding to plasma proteins. In order to have a coherent diagnostic and therapeutic approach and to understand diseases better, the combination of MRI and optical imaging (OI) techniques into one technique entity has been developed to overcome the conventional boundaries of either imaging modality used alone through bringing the excellent spatial resolution of MRI and high sensitivity of OI into full play. Novel MRI and OI bimodal probes have been extensively studied in this regard. This review is an attempt to shed some light on the bimodal imaging probes by summarizing all recent noteworthy publications involving Gd3+ containing MR-optical imaging probes. The several key elements such as novel synthetic strategy, high sensitivity, biocompatibility, and targeting of the probes are highlighted in the review. STATEMENT OF SIGNIFICANCE: The present article aims at giving an overview of the existing bimodal MRI and OI imaging probes. The review structured as a series of examples of paramagnetic Gd3+ ions, either as ions in the crystalline structure of inorganic materials or chelates for contrast enhancement in MRI, while they are used as optical imaging probes in different modes. The comprehensive review focusing on the synthetic strategies, characterizations and properties of these bimodal imaging probes will be helpful in a way to prepare related work.


Assuntos
Meios de Contraste , Gadolínio , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Imagem Óptica
14.
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
15.
Endocrine ; 69(1): 126-132, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32112240

RESUMO

CONTEXT: To prepare for radioactive iodine therapy in post total thyroidectomy patients with well-differentiated thyroid cancer (WDTC), either thyroid hormone withdrawal (THW) or administration of recombinant human thyrotropin (rhTSH) can be performed. OBJECTIVE: Our objective is to compare quality of life (QoL) parameters using the SF-36v2 questionnaire (Short Form health survey) and a self-evaluated item, and the hypothyroid status using modified Billewicz scores in an Asian population undergoing either THW or rhTSH for remnant ablation or adjuvant treatment following total thyroidectomy for WDTC. We will also assess the proportion of patients achieving TSH level of >30 mU/L after 4 weeks of thyroid hormone withdrawal. RESULTS: Patients in the rhTSH group were better in the QoL domains of physical functioning, role functioning/physical and bodily pain, while patients in THW group were better in mental health. This was however, not statistically significant. Modified Billewicz scores were higher in patients in THW group as compared with rhTSH group and statistically significant. A total of 96.3% of patients achieved TSH level >30 mU/L after 4 weeks of THW. CONCLUSION: Clinical symptoms and signs of hypothyroidism as assessed with modified Billewicz scores were statistically significantly higher in the THW group. However, there was no statistically significant difference in QoL in the rhTSH group.


Assuntos
Qualidade de Vida , Neoplasias da Glândula Tireoide , Humanos , Radioisótopos do Iodo , Proteínas Recombinantes , Hormônios Tireóideos , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Tireotropina
16.
Cardiovasc Intervent Radiol ; 43(3): 478-487, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31705243

RESUMO

OBJECTIVES: To determine the rate of prophylactic embolization of extrahepatic vessels in patients undergoing yttrium-90 selective internal radiotherapy (90Y SIRT) for hepatocellular carcinoma (HCC) with the use of catheter-directed computed tomography hepatic angiography (CD-CTHA). MATERIALS AND METHODS: This retrospective study included 186 HCC patients who received 90Y SIRT from May 2010 to June 2015 in a single institution. All procedures were performed in a hybrid angiography-CT suite equipped with digital subtraction angiography (DSA) and CD-CTHA capabilities. CD-CTHA was performed during pre-treatment hepatic angiography. 90Y SIRT was administered approximately 2 weeks later. Selective prophylactic embolization of extrahepatic vessels was performed if extrahepatic enhancement was seen on CD-CTHA or if an extrahepatic vessel opacified on DSA/CD-CTHA despite the final microcatheter position for 90Y microsphere delivery being beyond the origin of this vessel. RESULTS: Thirty-five patients (18.8%) required selective embolization of extrahepatic vessels. Technical success of 90Y SIRT was 99.5%. Two patients (1.1%) developed radiation-induced gastrointestinal ulceration, and one (0.54%) developed radiation-induced pneumonitis. Extrahepatic uptake of 90Y microspheres was seen in the gallbladder of one patient without significant complications. CONCLUSION: The use of CD-CTHA in 90Y SIRT of HCC was associated with a low rate of prophylactic embolization of extrahepatic vessels while maintaining a high technical success rate of treatment and low rate of complications. LEVEL OF EVIDENCE: Level 4, case series.


Assuntos
Braquiterapia/métodos , Carcinoma Hepatocelular/radioterapia , Angiografia por Tomografia Computadorizada/instrumentação , Angiografia por Tomografia Computadorizada/métodos , Neoplasias Hepáticas/radioterapia , Radiografia Intervencionista/métodos , Radioisótopos de Ítrio , Carcinoma Hepatocelular/diagnóstico por imagem , Cateteres , Feminino , Artéria Hepática/diagnóstico por imagem , Humanos , Fígado/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Radiografia Intervencionista/instrumentação , Estudos Retrospectivos
17.
Clin Transplant ; 33(10): e13671, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31332844

RESUMO

The evolution of trabecular bone score (TBS) and bone mineral density (BMD) over the first 5 years after renal transplantation was prospectively evaluated in 164 patients. Dual energy X-ray absorptiometry (DXA) scans were performed at 0, 6, 12, 24, and 60 months. Cumulative steroid dose, serum 25(OH)D, calcium, parathyroid hormone, and total ALP levels at these time points were checked. Incident fractures were identified from X-rays/vertebral fracture assessments. Mean (SD) age, TBS, and lumbar spine BMD at baseline were 47.11 (9.53), 1.424 (0.097), and 0.935 (0.183) gm/cm2 , respectively. Baseline TBS was lower in tertiary 1.38 (0.07) vs secondary hyperparathyroidism 1.43 (0.01) vs post-parathyroidectomy 1.46 (0.11); P = .035. Trabecular bone score and BMD significantly decreased from baseline->6 months, changes after that at consecutive time points were non-significant. 11% had incident fractures during the follow-up period, majority being metatarsal with no vertebral or hip fractures noted. This first prospective evaluation of TBS and BMD evolution at multiple time points over 5 years suggest that microarchitectural and bone density deteriorations post-renal transplantation stabilize after 6 months. Stabilization of these parameters could partially account for the absence of major fractures noted in this Asian population. Possible genetic and ethnic differences in fracture risk between Asian and Caucasian renal transplant patients have to be explored through large population-based studies.


Assuntos
Densidade Óssea , Osso Esponjoso/fisiopatologia , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Fraturas por Osteoporose/patologia , Medição de Risco/métodos , Absorciometria de Fóton , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/etiologia , Prognóstico , Estudos Prospectivos , Fatores de Risco
18.
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.

19.
Neuroendocrinology ; 108(4): 265-277, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30399612

RESUMO

BACKGROUND: Epidemiological evidence suggests there are differences in gastroenteropancreatic neuroendocrine neoplasm (GEPNEN) among population groups. We aimed to contribute to the current evidence by evaluating the clinicopathological characteristics of GEPNEN in a multi-ethnic Asian group. MATERIALS AND METHODS: This was a retrospective chart review of patients diagnosed with GEPNEN at a tertiary medical institution at Singhealth Outram Campus, Singapore, between 1995 and 2015. RESULTS: Two hundred ninety-five patients were included in the evaluation, comprising Chinese (74.6%), Malay (4.4%), Indian (9.5%) and other (11.5%) ethnic backgrounds. The median age at diagnosis was 59 years; 52.5% were males. Distribution of disease stage at diagnosis was: localised (42.4%), regional (15.3%) and distant (38.0%). The three most common primary tumour sites were located in the pancreas (38.6%), rectum (19.7%) and stomach (9.5%), which varied significantly with ethnic background and age at diagnosis. Malay patients were younger (median 42 years) at diagnosis than Chinese (60 years). Patients with an appendiceal neuroendocrine neoplasm (NEN) (48 years) were younger compared to oesophageal NEN (66 years). Disease stage correlated with primary tumour site and grade (p < 0.001). Median overall survival (OS) for all GEPNEN was 10.2 years. Age at diagnosis, disease stage and grading were prognostic factors of OS in multivariable analyses. CONCLUSION: Our findings correspond with other studies that focus on GEPNEN incidences in Asian countries, with the pancreas, rectum and stomach being the most common primary tumour sites. Our findings suggest racial differences in primary tumour site and age at diagnosis. Further prospective population-based registries are required to understand these epidemiological differences.


Assuntos
Neoplasias Intestinais/patologia , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/patologia , Neoplasias Gástricas/patologia , Idoso , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias Gástricas/diagnóstico
20.
Eur J Radiol ; 105: 289-295, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30017295

RESUMO

BACKGROUND: Systemic sclerosis-associated gastrointestinal tract involvement (SSc-GIT) is an independent predictor of 2-year mortality in early SSc. Availability of non-invasive investigations will facilitate early diagnosis and monitoring. HYPOTHESIS: We investigate the role of 18F-FDG-PET-MRI in SSc-GIT, hypothesizing that i) higher bowel FDG-PET uptake, a surrogate biomarker for inflammation, distinguishes healthy bowel from inflamed SSc-GIT; ii) MRI T1-MOLLI mapping, a surrogate biomarker for cardiac fibrosis, distinguishes healthy bowel from fibrotic SSc-GIT. METHODS: In this prospective study, 16 SSc patients and 15 healthy controls were recruited. All SSc patients and 5 controls underwent PET-MRI (with T1-MOLLI mapping) on a Siemens 3T mMR; 10 controls underwent MRI without PET. Manual segmentation of the large and small bowels was performed jointly by two trained analysts in order to report T1 and PET values. Control dataset was used to assess normal healthy range. Mean T1 values, mean Tissue-to-Background (TBR) PET values, as well as amount of supposedly abnormal bowel (measured using the healthy ranges) was compared using Student's t-test and Cohen's d effect size. RESULTS: Mean T1 values in large (1113 ±â€¯182 ms vs 856 ±â€¯176 ms; p-value < 0.001) and small bowel (1331 ±â€¯239 ms vs 1169 ±â€¯118 ms; p = 0.02) were higher in SSc patients than controls. 87.5% of the SSc patients' bowel had at least a grade 3 segmental FDG-PET uptake, while no controls showed more than a grade 2 segmental uptake. Patients had higher large bowel mean PET TBR (1.12 ±â€¯0.22) than controls (0.82 ±â€¯0.20, p = 0.02). Using PET and T1 thresholds defined using the control PET-MR data, the percentage of supposedly healthy (non-fibrotic and non-inflamed) tissue was significantly lower in SSc patients (81.1 ±â€¯13.1%) than controls (95.7 ±â€¯3.1%, p = 0.03) for the large bowel. CONCLUSION: Our novel study of FDG-PET-MRI in SSc-GIT demonstrated promising results in non-invasively evaluating concurrently bowel inflammation and fibrosis.


Assuntos
Fibrose/diagnóstico por imagem , Fluordesoxiglucose F18 , Inflamação/diagnóstico por imagem , Enteropatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Escleroderma Sistêmico/diagnóstico por imagem , Simulação por Computador , Estudos Cross-Over , Feminino , Fibrose/patologia , Humanos , Processamento de Imagem Assistida por Computador , Inflamação/patologia , Enteropatias/patologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Tomografia por Emissão de Pósitrons/métodos , Reprodutibilidade dos Testes , Escleroderma Sistêmico/patologia
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