Purpose: A novel [⁶⁸Ga]-labeled DOTA-4-amino-1-carboxymethyl-piperidine-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH₂ peptide (BAY86-7548) having high affinity to bombesin receptor subtype II to detect primary and metastatic prostate carcinoma using positron emission tomography/computed tomography (PET/CT) was synthesized and evaluated for prostate cancer. Experimental Design: In this first human study with BAY86-7548, 14 men scheduled for radical prostatectomy (n = 11) or with biochemical recurrence after surgery or hormonal therapy (n = 3) were enrolled. The patients received an intravenous injection of BAY86-7548 followed by over 60-minute dynamic imaging of prostate gland (n = 10) and/or subsequent whole-body imaging (n = 14). The visual assessment of PET/CT images included evaluation of intraprostatic (12 subsextants) and pelvic nodal uptake of BAY86-7548 in 11 surgical patients and detection of potential metastatic foci in all patients. In patients with biochemical recurrence, results were compared with those of either [¹¹C]-acetate (n = 2) or [¹⁸F]-fluoromethylcholine (n = 1) PET/CT. Results: We found a sensitivity, specificity, and accuracy of 88%, 81% and 83%, respectively, for detection of primary PCa and sensitivity of 70% for metastatic lymph nodes using histology as gold standard. BAY86-7548 correctly detected local recurrence in prostate bed and showed nodal relapse in accordance with [¹¹C]-acetate PET/CT in 2 patients with biochemical relapse. In the third hormone refractory patient, BAY86-7548 failed to show multiple bone metastases evident on [¹⁸F]-fluoromethylcholine PET/CT. Conclusion: BAY86-7548 PET/CT is a promising molecular imaging technique for detecting intraprostatic prostate cancer. Clin Cancer Res; 19(19); 5434–43. ©2013 AACR.

Objective: Brain acetylcholinesterase activity was determined in healthy controls and in patients with mild cognitive impairment and early Alzheimer’s disease. Methods: A specific acetylcholinesterase tracer, [methyl-¹¹C]N-methyl-piperidyl-4-acetate ([¹¹C]MP4A), and a three dimensional PET system with magnetic resonance coregistration were used for imaging. Results: There was a significant difference in the acetylcholinesterase activity in the hippocampus between the groups (p = 0.03), the mean (SD) acetylcholinesterase activity (k₃ values, min⁻¹) being 0.114 (0.036) in controls, 0.098 (0.023) in mild cognitive impairment, and 0.085 (0.022) in Alzheimer’s disease. The mini-mental state examination score showed no significant relation with acetylcholinesterase activity in any brain area in the combined mild cognitive impairment/Alzheimer group. Conclusions: Hippocampal acetylcholinesterase activity is only slightly reduced in mild cognitive impairment and early Alzheimer’s disease and so the value of in vivo acetylcholinesterase measurements in detecting the early Alzheimer process is limited.