The procurement seeks one Siemens Vision 600 PET/CT scanner or equivalent to replace an existing system reaching end of service life on 31DEC2026. The replacement is urgently needed to continue clinical PET/CT scans for adult and pediatric patients with cancer and other serious conditions at the Clinical Center. The new system must provide state-of-the-art sensitivity, resolution, and field of view to improve lesion detection and support accurate diagnosis and treatment planning. This acquisition is required for continuity of safe patient care and to support innovative clinical research protocols. Expedited procurement processing is requested due to the urgency.