Final answer:
The minimum distance from source-to-table top for a fixed fluoroscopic unit should be at least 38 cm to reduce radiation exposure for safety.
Step-by-step explanation:
The minimum distance from source-to-table top for a fixed fluoroscopic unit should typically be at least 38 cm (15 inches), as recommended by various radiation safety guidelines. This minimum distance is set to ensure sufficient spatial separation to reduce radiation exposure to the patient. In the context of fluoroscopic procedures, it is crucial to maintain optimal distance to protect both patient and operating staff from unnecessary radiation. Safety measures such as lead aprons, fast films, and appropriate shielding, like those mentioned with respect to dental x-rays, are also applicable in fluoroscopy to minimize radiation doses. The technician's position, often shielded by a lead-lined door or window, further exemplifies protective measures taken during radiographic procedures.