Maintenance-Induced Configuration Drift in Nuclear Medicine Quality Control: The Role of Technologists and Site...

Maintenance-induced configuration drift detected during a 3-lot validation study is described, highlighting the role of nuclear medicine technologists and site engineers in its resolution. A radio-high-performance liquid chromatography system was used during validation of a new positron-emitting radiopharmaceutical. After routine maintenance, reduced peak intensity was observed despite otherwise normal operation. An investigation was conducted by nuclear medicine technologists and site engineers. The reduced peak intensity was traced to an unintended shift in the detector energy window from the standard 511 keV to approximately 400 keV. Peak intensities decreased to approximately 40%-60% of expected values. Restoration of the correct setting recovered normal performance. Maintenance may introduce configuration drift that is not detected through routine operational checks. Postmaintenance verification by nuclear medicine technologists is important, particularly during validation studies.