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Objectives The Phase I safety, biodistribution and internal radiation dosimetry study in adult healthy Japanese males of flutemetamol (18F) injection, an in vivo β-amyloid imaging agent, is reported and compared with previously obtained Caucasian data.

Carbon Monoxide (CO) is one of the leading causes of poison deaths in the United States. Signs and symptoms are clinically variable secondary to inconsistent targeting of highly metabolic tissues by the gas. We report a case of a man in his early to mid-30’s presenting to the emergency department with mental status changes, fatigue, headache, and flu-like symptoms for three days. The patient had been working on his motor vehicles in the garage during this time, using a portable diesel powered space heater to keep warm. Subsequent neurology and cardiology workup demonstrated bilateral globus pallidus (GP) lesions on brain imaging, increased non-myocardial infarction troponin levels, carboxyhemoglobin (COHb) level of 3.8%, elevated liver enzymes, and acute kidney failure. In this setting of his delayed presentation as a smoker with carbon monoxide poisoning, carboxyhemoglobin levels alone become less reliable. This report investigates the use of bilateral GP lesions, the most frequently affected structure, as well as damage preference to highly metabolic tissues to assist in diagnosis and prognosis for CO poisoning. Our observations can be used for further study of the relationship between bilateral GP necrosis and initial presentation and outcome of patients experiencing CO poisoning leading to earlier recognition, treatment, and decreased morbidity/mortality.

We report on the biodistribution and internal radiation dosimetry in humans of [18F]fluciclovine, a synthetic L-leucine analogue being investigated as a potential diagnostic biomarker for neoplasia. Whole-body positron emission tomography (PET) scans of 6 healthy volunteers were acquired at up to 16 time points up to about 5 h after a bolus administration of [18F]fluciclovine (153.8 ± 2.2 MBq). Venous blood samples were taken up to about 4 h post-injection from which 18F activity concentrations in whole blood and plasma were measured. Urine was collected as voided up to 4 h post-injection, from which the excreted 18F activity was measured. Absolute values of the 18F activity contained in up to 11 source regions (brain, salivary glands, lung, heart, pancreas, spleen, liver, red bone marrow, kidneys, uterus and urinary bladder contents) were determined directly from quantitative analysis of the images. For each source region, the 18F activity decay-corrected and normalised to that injected, as a function of time, was fit by an analytical function which was subsequently integrated to yield the cumulated activity normalised to the injected activity. These normalised cumulated activities were then used as input to the Organ Level INternal Dose Assessment/EXponential Modelling (OLINDA/EXM) package to calculate the internal radiation dosimetry of each subject following the Medical Internal Radiation Dose (MIRD) schema. An effective dose was then estimated for each subject. [18F]Fluciclovine was clinically well tolerated in this study. Very little 18F was excreted with only a mean value of 3.3 % present in the urine at about 4 h post-injection; no activity within the intestinal contents was noted. The highest mean initial uptakes were measured in the liver (13.8 %), red bone marrow (11.1 %) and lung (7.1 %). The highest mean radiation absorbed doses per unit administered activity were received by the pancreas (102.2 μGy/MBq), the cardiac wall (51.7 μGy/MBq) and the uterine wall (44.6 μGy/MBq). The mean effective dose per unit administered activity was 22.1 μSv/MBq. The internal radiation dosimetry of [18F]fluciclovine appears acceptable for PET imaging.

We report the safety, biodistribution, and internal radiation dosimetry of a new PET tracer, (18)F-AH111585, a peptide with a high affinity for the alpha(v)beta(3) integrin receptor involved in angiogenesis.PET scans of 8 healthy volunteers were acquired at time points up to 4 h after a bolus injection of (18)F-AH111585. (18)F activity in whole blood and plasma and excreted urine were measured up to 4 h after injection. In vivo (18)F activities in up to 12 source regions were determined from quantitative analysis of the images. The cumulated activities subsequently calculated were then used to determine the internal radiation dosimetry, including the effective dose.Injection of (18)F-AH111585 was well tolerated in all subjects, with no serious or drug-related adverse events reported. The main route of (18)F excretion was renal (37%), and the 3 highest initial uptakes were by liver (15%); combined walls of the small, upper large, and lower large intestines (11%); and kidneys (9%). The 3 highest absorbed doses were received by the urinary bladder wall (124 microGy/MBq), kidneys (102 microGy/MBq), and cardiac wall (59 microGy/MBq). The effective dose was 26 microGy/MBq.(18)F-AH111585 is a safe PET tracer with a dosimetry profile comparable to other common (18)F PET tracers.

The integrin αvβ3 receptor is upregulated on tumor cells and endothelium and plays important roles in angiogenesis and metastasis. Arg-Gly-Asp (RGD) peptide ligands have high affinity for these integrins and can be radiolabeled for PET imaging of angiogenesis or tumor development. We have assessed the safety, stability, and tumor distribution kinetics of a novel radiolabeled RGD-based integrin peptide-polymer conjugate, 18F-AH111585, and its feasibility to detect tumors in metastatic breast cancer patients using PET. Methods: The biodistribution of 18F-AH111585 was assessed in 18 tumor lesions from 7 patients with metastatic breast cancer by PET, and the PET data were compared with CT results. The metabolic stability of 18F-AH111585 was assessed by chromatography of plasma samples. Regions of interest (ROIs) defined over tumor and normal tissues of the PET images were used to determine the kinetics of radioligand binding in tissues. Results: The radiopharmaceutical and PET procedures were well tolerated in all patients. All 18 tumors detected by CT were visible on the 18F-AH111585 PET images, either as distinct increases in uptake compared with the surrounding normal tissue or, in the case of liver metastases, as regions of deficit uptake because of the high background activity in normal liver tissue. 18F-AH111585 was either homogeneously distributed in the tumors or appeared within the tumor rim, consistent with the pattern of viable peripheral tumor and central necrosis often seen in association with angiogenesis. Increased uptake compared with background (P = 0.002) was demonstrated in metastases in lung, pleura, bone, lymph node, and primary tumor. Conclusion:18F-AH111585 designed to bind the αvβ3 integrin is safe, metabolically stable, and retained in tumor tissues and detects breast cancer lesions by PET in most anatomic sites.