Optimizing Low-Dose [18F]FDG-PET/CT Scans: Ensuring Quality Amid Radiotracer Availability Challenges - Insights from a Peripheral Tertiary Care Center.

Background: The introduction of positron emission tomography/computed tomography (PET/CT) has significantly advanced medical imaging. In oncology, ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT is particularly crucial for staging, evaluating treatment response, monitoring follow-up, and planning radiotherapy. However, in resource limiting hospitals, the availability of fluorine-labeled ¹⁸F-FDG limits optimal scan acquisition. This study aims to determine the optimal dosage and acquisition time to maximize patient throughput during shortages.

Aim and objective: To optimize low-dose ¹⁸F-FDG scan protocols while maintaining high image quality despite radiotracer availability challenges.

Materials and methods: PET/CT scans were performed using GE's Discovery IQ 5-ring, 16-slice system within 40-60 minutes of intravenous ¹⁸F-FDG injection. The protocol was adjusted to a low-dose (0.05 mCi/kg of ¹⁸F-FDG), and the PET data acquisition time was increased to 3 min per bed position to ensure image quality.

Results: Notable differences were observed in image quality scores based on varying acquisition times, with the extended acquisition time helping maintain diagnostic standards despite reduced tracer doses.

Conclusion: The high sensitivity and long axial length of the PET/CT system (with five rings spanning 26 cm AFOV) can significantly alleviate the challenges faced by cyclotron-dependent centers. By leveraging the increased sensitivity, we successfully reduced the injected activity rather than the scan time to address the tracer shortage at our institute. This approach proved to be effective in maintaining image quality and patient care standards.