Noninvasive Verification of a Very Small Intraocular Prostate Carcinoma Metastasis by 68Ga-PSMA-11 PET/CT.

ABSTRACT: A male patient underwent 68Ga-PSMA-11 PET/CT for the evaluation of a suspected intraocular metastasis in the right eye. Although the choroidal thickening was very small (4 × 2 mm), and ophthalmoscopy as well as MRI were inconclusive, PET/CT imaging showed distinct PSMA expression in the suspected lesion, confirming prostate cancer metastasis. The ability of dedicated PSMA ligand PET/CT imaging to detect small metastases, even with 68Ga-labeled ligands, has been demonstrated. Therefore, the use of further invasive diagnostic procedures could be avoided. Thus, the possibility of detecting intraocular metastases of prostate cancer should be considered in routine PET/CT imaging.

The effect of butylscopolamine on [18F]FDG uptake in the gastrointestinal tract is negligible and regionally variable.

BACKGROUND: Butylscopolamine (or hyoscine butylbromide, trade name Buscopan®) is occasionally administered as a premedication to reduce non-specific FDG uptake in the gastrointestinal tract based on its antiperistaltic effect. To date, there are no consistent recommendations for its use. The aim of this study was to quantify the reduction in intestinal and non-intestinal uptake by butylscopolamine administration and to derive relevance for clinical evaluation. RESULTS: 458 patients (PET/CT for lung cancer) were retrospectively reviewed. 218 patients with butylscopolamine and 240 patients without butylscopolamine had comparable characteristics. While the SUVmean in the gullet/stomach and small intestine was significantly reduced with butylscopolamine, the colon and rectum/anus showed no difference. The liver and salivary glands showed a reduced SUVmean, while skeletal muscle and blood pool were unaffected. An effect of butylscopolamine was particularly evident in men and patients under 65 years of age. There was no difference in the perceived confidence in the assessment of intestinal findings in the subjective evaluation, although in the butylscopolamine group further diagnostics appeared advisable more frequently. CONCLUSIONS: Butylscopolamine reduces gastrointestinal FDG accumulation only in selected segments and, despite a significant effect, only to a small extent. A general recommendation for the use of butylscopolamine cannot be derived from these results, its use for specific issues could be considered individually.

Complete Right-to-Left Shunt in Lung Perfusion Scintigraphy.

ABSTRACT: Lung scintigraphy was performed to rule out pulmonary embolism in a 37-year-old woman suffering from dyspnea and hypoxemia after routine diagnostics failed to find the underlying disease. Perfusion scans did not show tracer uptake within the lungs despite ventilation scans being unremarkable. Instead, the result suggested a complete right-to-left shunt, which was a conundrum. With the assistance of CT an uncommon congenital vessel aberration turned out to be the cause of this exceptional scintigraphy finding, as well as the yet unexplained hypoxemia.