ABSTRACT
Prostate cancer brain metastases are rare but increasingly recognized with prostate-specific membrane antigen (PSMA) PET/CT. Distinguishing tumor response from postradiation changes are challenging on MRI. PSMA PET/CT may clarify equivocal brain lesions after radiotherapy. A 71-year-old man with metastatic prostate cancer developed 2 new brain lesions on PSMA PET/CT. Lesions were high PSMA-avid and MRI follow up showed enhancing masses with edema, consistent with metastases. He underwent whole-brain radiation. Follow-up PSMA PET/CT after radiotherapy demonstrated significantly decreased lesion size and activity, with activity lower than blood pool, indicating a treatment response. MRI also showed near-resolution of the lesions. This case highlights the potential utility of PSMA PET/CT for detecting prostate cancer brain metastases and monitoring treatment response. PSMA PET/CT provides valuable complementary information to MRI for managing irradiated prostate cancer brain metastases.
ABSTRACT
Paragangliomas are extra-adrenal catecholamine-secreting neuroendocrine tumors that can present with adrenergic signs and symptoms. The urinary bladder is a rare location for a paraganglioma, and these tumors must be distinguished from other more common bladder neoplasms. In this case report, we discuss a 59 year-old woman who initially presented with tachycardia, palpitations, chest tightness, shortness of breath, and weight loss. Laboratory evaluation showed significantly elevated catecholamines in the plasma and urine. A CT (Computed Tomography) scan of the abdomen and pelvis revealed an enhancing mass arising from the urinary bladder and an enlarged right pelvic lymph node. A follow up Ga-68 DOTATATE PET/CT (Positron Emission Tomography and/or Computed Tomography) showed increased uptake in the primary bladder mass, right pelvic lymph node, numerous skeletal lesions, and pulmonary nodules, consistent with metastatic paraganglioma of the urinary bladder. This case report demonstrates the radiological findings of metastatic urinary bladder paraganglioma and highlights the importance of skull base to mid-thigh PET/CT using Ga-68 DOTATATE. It is crucial for the radiologist to be familiar with the characteristics of urinary bladder paragangliomas and identify these tumors on imaging to allow prompt initiation of surgical resection and/or systemic therapy.
ABSTRACT
Several nuclear imaging techniques can be used to diagnose infectious and inflammatory processes. F-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a useful diagnostic technique to detect inflammation and infection quickly and accurately. We report the case of a patient with end-stage renal disease (ESRD) and recurrent bacterial infections where FDG PET/CT was used to identify the source of infection as sternal osteomyelitis and rule out suspected infection of the aortic valve prosthesis.
ABSTRACT
Radiologic imaging techniques, such as F-18-fluorodeoxyglucose positron emission tomography/computerized tomography (FDG PET/CT), provide diagnostic value in a variety of diseases. In cases of suspected infection, FDG PET/CT can find areas of fluorodeoxyglucose metabolism, correlating with local acute inflammation. The following case involves a man with end-stage renal disease (ESRD), who presented with symptoms of infection and positive blood cultures with high suspicion of arteriovenous fistula as the source of infection. The patient also had two central lines that could be a site of infection. Concerns for patient's persistent positive blood cultures necessitated FDG PET/CT to confirm site of infection. Confirming active infection and the source of infection guides therapeutic measures and eliminates concern for other disease etiologies common in patients with ESRD.
