RESUMO
OBJECTIVE: The objective of this study is to determine the optimal ß value for clinical use in digital 68 Ga-prostate-specific membrane antigen (PSMA-11) PET/computed tomography (CT) imaging. METHODS: 68 Ga PSMA PET/CT of 21 patients with prostate cancer were reconstructed using block-sequential regularized expectation maximization ( ß value of 400-1600) and ordered subsets expectation maximization. Nine independent blinded readers evaluated each reconstruction for overall image quality, noise level and lesion detectability. Maximum standardized uptake value (SUVmax) of the most intense lesion, liver SUVmean and liver SUV SD were recorded. Lesions were then subdivided according to uptake and size; the SUVmax of these lesions were analyzed. RESULTS: There is a statistically significant correlation between improvement in image quality and ß value, with the best being ß 1400. This trend was also seen in image noise ( P â <â 0.001), with the least image noise reported with ß 1400. Lesion detectability was not significantly different between the different ß values ( P â =â 0.6452). There was no statistically significant difference in SUVmax of the most intense lesion ( P â =â 0.9966) and SUVmean of liver background between the different ß values ( P â =â 0.9999); however, the SUV SD of the liver background showed a clear trend, with the lowest with ß 1400 ( P â =â 0.0008). There was a decreasing trend observed in SUVmax when ß values increased from 800 to 1400 for all four subgroups, and this decrease was greatest in small and low uptake lesions. CONCLUSION: Bayesian penalized likelihood reconstruction algorithms improve image quality without affecting lesion detectability. A ß value of 1400 is optimal.
Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata , Masculino , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Próstata , Teorema de Bayes , Tomografia Computadorizada por Raios X , Neoplasias da Próstata/diagnóstico por imagemAssuntos
Antibióticos Antineoplásicos/efeitos adversos , Fístula Brônquica/etiologia , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/efeitos adversos , Fístula do Sistema Digestório/etiologia , Doxorrubicina/efeitos adversos , Abscesso Hepático/etiologia , Hepatopatias/etiologia , Neoplasias Hepáticas/terapia , Idoso de 80 Anos ou mais , Antibióticos Antineoplásicos/administração & dosagem , Fístula Brônquica/diagnóstico , Fístula Brônquica/terapia , Carcinoma Hepatocelular/patologia , Fístula do Sistema Digestório/diagnóstico , Fístula do Sistema Digestório/terapia , Doxorrubicina/administração & dosagem , Humanos , Abscesso Hepático/diagnóstico , Abscesso Hepático/terapia , Hepatopatias/diagnóstico , Hepatopatias/terapia , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Carga TumoralRESUMO
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.