RESUMEN
ABSTRACT: 18F-PSMA PET/CT is an emerging standard of care in staging prostate cancer, evaluating biochemical recurrence and response to therapy. Despite the nomenclature, PSMA expression is also documented at the tumor-associated neovasculature of other malignant solid tumors including renal cell carcinoma. We report a case of 44-year-old man known to have renal cell carcinoma who underwent 18F-PSMA and 18F-FDG PET/CT for restaging after radical nephrectomy. A well-defined solitary cerebellar lesion with marked PSMA expression and equivocal FDG uptake was noted. MRI brain confirmed a matching cerebellar metastatic lesion. 18F-PSMA expression in the metastatic RCC raises a prospective guide to futuristic theragnostic uses.
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Carcinoma de Células Renales , Neoplasias Renales , Neoplasias de la Próstata , Adulto , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/patología , Radioisótopos de Galio , Humanos , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/patología , Masculino , Niacinamida/análogos & derivados , Oligopéptidos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Estudios Prospectivos , Neoplasias de la Próstata/patología , RadiofármacosRESUMEN
A 64-year-old woman with metastatic breast cancer on follow-up had suspicious recurrent brain metastases. She underwent F-FDG PET/CT, F-PSMA 1007 brain PET/CT, and brain MRI. F-PSMA 1007 showed intense tracer localization in the suspected recurrent brain metastasis in right parietal lobe and also picked up 2 more metastatic brain lesions, which had concurrent findings of metastasis in subsequent MRI. Our case highlights the feasibility of F-PSMA 1007 PET/CT imaging of brain metastases from nonprostate cancers. It may be used as surrogate imaging tracer for potential theranostic application using alpha or beta emitters considering its similarity to PSMA-617.
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Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/secundario , Neoplasias de la Mama/patología , Niacinamida/análogos & derivados , Oligopéptidos/metabolismo , Transporte Biológico , Neoplasias Encefálicas/diagnóstico por imagen , Femenino , Humanos , Persona de Mediana Edad , Niacinamida/metabolismo , Tomografía Computarizada por Tomografía de Emisión de PositronesRESUMEN
A 60-year-old man with suspected right renal cell carcinoma underwent F-FDG PET/CT and F prostate-specific membrane antigen (PSMA) 1007 PET/CT scan. Compared with the F-FDG PET/CT scan, F-PSMA 1007 PET/CT showed intense tracer concentration in the primary tumor in the right kidney and intense tracer concentration consistently in all lung nodules. Unlike noted in previous pilot studies with Ga-PSMA, we observed that the primary renal tumor also showed intense tracer avidity with F-PSMA 1007. F-PSMA 1007 PET/CT may provide preoperative insight into possible etiology, histopathological probability of tumor type, staging information, and theranostic potentials in evaluation of suspected renal cell carcinoma.
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Carcinoma de Células Renales/diagnóstico por imagen , Neoplasias Renales/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Radioisótopos de Flúor , Humanos , Masculino , Persona de Mediana Edad , Niacinamida/análogos & derivados , Oligopéptidos , RadiofármacosRESUMEN
Various positron emission tomography (PET) studies are available for prostate cancer which show various successes at demonstrating primary, recurrent, or metastatic tumor and assessing response to treatment. In this case report, we will present and compare pre- and post-therapy fluorodeoxyglucose, sodium fluoride, and gallium-68 prostate-specific membrane antigen PET images of a patient with prostate cancer.
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We incidentally identified gallbladder activity on 18F sodium fluoride (NaF) positron emission tomography/computed tomography (PET/CT) bone images in five patients. Variable degree of bowel activity is usually seen on NaF PET/CT images, and its mechanism is unknown. Gallbladder activity in our cases may indicate that hepatobiliary excretion of the 18F NaF is the reason for bowel activity on NaF PET/CT images. However, excretion of radiotracer through bowel may also contribute to the bowel activity.
RESUMEN
Gallium-68 prostate-specific membrane antigen (Ga-68 PSMA) ligand (HBED-CC) is a new promising positron emission tomography (PET) tracer for prostate cancer. Intense renal parenchymal uptake is a physiologic finding on Ga-68 PSMA ligand PET images. Evaluation of kidneys in low intensity demonstrates excellent distribution of this radiotracer in renal parenchyma with excellent image quality and resolution. In this article, we present the Ga-68 PSMA ligand PET renal images of four patients with prostate cancer. In two patients, there is normal distribution of radiotracer, and in other two, there are renal cysts causing parenchymal defects.
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The use of F-18 sodium fluoride (NaF) positron emission tomography/computed tomography (PET/CT) bone scan is increasing because of its higher sensitivity and specificity over standard bone scintigraphy (BS). Studies previously reported a prostate-specific antigen (PSA) cutoff value for ordering standard BS. However, this has not been determined for NaF PET yet. In this study, our goal was to determine a PSA cutoff level for ordering NaF PET/CT bone scan. Newly diagnosed and previously treated prostate cancer patients who had NaF PET/CT scan and PSA measurements within 2 mos of PET study were selected for analysis. When available, other parameters, such as Gleason score (GS), clinical stage, alkaline phosphatase levels, skeletal symptoms, and correlative image findings, were recorded. Receiver operating characteristic (ROC) analysis was performed to determine PSA cutoff values. Sixty-two patients (32 newly diagnosed and 30 previously treated) met the inclusion criteria. Near half of previously treated patients were on hormone therapy. NaF PET/CT was positive in 9 newly diagnosed (PSA mean: 91.6 ng/ml, range: 6.2-226 ng/ml) and in 6 previously treated patients (PSA mean: 146.4 ng/ml, range: 6.6-675 ng/ml). ROC analysis indicated that PSA cutoff value for NaF PET/CT positivity was >20 ng/ml in newly diagnosed and >6 ng/ml in previously treated patients. PSA cutoff value for ordering NaF PET/CT in newly diagnosed patients does not seem significantly different than the previous results for BS (>20 ng/ml). However, we found a lower PSA cutoff value of >6 ng/ml in previously treated patients.
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Fluorine-18-sodium fluoride (F-NaF) PET/CT is a relatively new and high-resolution bone imaging modality. Since the use of F-NaF PET/CT has been increasing, it is important to accurately assess the images and be aware of normal distribution and major artifacts. In this pictorial review article, we will describe the normal uptake patterns of F-NaF in the bone tissues, particularly in complex structures, as well as its physiologic soft tissue distribution and certain artifacts seen on F-NaF PET/CT images.
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Artefactos , Huesos/diagnóstico por imagen , Radioisótopos de Flúor , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Fluoruro de Sodio , Huesos/metabolismo , Humanos , Fluoruro de Sodio/metabolismo , Fluoruro de Sodio/farmacocinética , Distribución TisularRESUMEN
Ewing sarcoma is the second most common pediatric malignant bone tumor. It usually presents as a hot spot on a 3-phase bone scan as a result of increased vascularity of the tumor and new bone formation. However, aggressive Ewing sarcoma can also appear as a cold lesion. We present the features of a Ewing sarcoma of the rib on a 3-phase bone scan in a child who was being investigated for rib fracture after trauma.
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Neoplasias Óseas/irrigación sanguínea , Neoplasias Óseas/diagnóstico por imagen , Fracturas de las Costillas/diagnóstico por imagen , Costillas/irrigación sanguínea , Costillas/diagnóstico por imagen , Sarcoma de Ewing/irrigación sanguínea , Sarcoma de Ewing/diagnóstico por imagen , Velocidad del Flujo Sanguíneo , Niño , Imagen de Acumulación Sanguínea de Compuerta/métodos , Humanos , Hallazgos Incidentales , Masculino , Costillas/lesionesAsunto(s)
Riñón/anomalías , Riñón/diagnóstico por imagen , Ácido Dimercaptosuccínico de Tecnecio Tc 99m , Vejiga Urinaria/anomalías , Vejiga Urinaria/diagnóstico por imagen , Adulto , Diagnóstico Diferencial , Humanos , Masculino , Palpación , Radiografía , Renografía por Radioisótopo , RadiofármacosRESUMEN
OBJECTIVE: To perform a comparison between post-stress and rest gated single-photon emission computer tomography (SPECT) myocardial perfusion imaging (MPI) studies to assess post-stress stunning and the variables underlying this phenomenon. SUBJECTS AND METHODS: This was a prospective study of 318 consecutive adult patients undergoing stress and rest gated SPECT using a 2-day (99m)Tc-tetrofosmin protocol. Bruce protocol treadmill stress (n = 93) or i.v. dipyridamole pharmacologic stress (n = 225) were used as stressors. Ejection fractions (EF) and left ventricular (LV) end-diastolic (EDV) and end-systolic volumes (ESV) were calculated using the Cedars Sinai Quantitative Gated SPECT software. Perfusion defects were visually scored using a 20-segment model to obtain summed stress scores. Statistical analysis was performed by applying paired t test and multi-regression. Statistically significant (p < 0.05) paired differences between post-stress and rest EF and ESV and type of stressing were noted. RESULTS: Analysis of patient groups based on the type of stress showed significantly low EF on post-stress studies for both treadmill and dipyridamole stressing and also significantly high ESV on post-stress studies for dipyridamole. Multi-regression analysis using differences in post-stress and rest EF, EDV and ESV as dependent and summed stress scores, type of stress, delay time, previous myocardial infarction and size of LV as independent variables showed statistically significant associations between high summed stress scores (>13) and size of post-stress LV for EDV and ESV differences. High volumes were noted on post-stress studies. The magnitudes of the observed differences were well within the reproducibility of LV volume calculations. CONCLUSIONS: Patients showing stunning had significant ischemia or a dilated LV. The stunning manifested as high EDV and ESV differences. The magnitude of the differences observed in EF and LV volumes were not clinically significant.