摘要Objective:This study aims to verify the feasibility of reducing the in-jected activity of 18F-FDG by shortening the bed-dwell time based on body weight,and to design a weight-stratified radiation dose optimization system to balance image quality and safety in adult tumor patients.Methods:A total of 100 tumor patients were selected and divided into a training set(70 cases)and a validation set(30 cas-es)in a 7∶3 ratio using the hold-out method.All patients received a standard injec-tion of 18F-FDG at 5.3 MBq/kg and underwent whole-body scanning on a PHILIPS Ingenuity TF PET-CT system(VIP recording mode,180 s/bed position for the train-ing set).Six low-dose datasets were generated from the training set by simulating different bed-dwell times(60-160 s/bed position).The lesion detection concordance rate,subjective confidence,SUVmax error,and signal-to-noise ratio(SNR)were com-pared across different body weight subgroups.The validation set was scanned ac-cording to the optimization system derived from the training set to evaluate its effects on image quality,injected 18F-FDG activity,and PET radiation dose.Results:For patients with body weight>70 kg,a bed-dwell time≥120 s/bed position achieved a lesion detection rate of 92%and an SUVmax error<5%.For patients with body weight≤70 kg,a bed-dwell time≥140 s/bed position was required to maintain compara-ble diagnostic accuracy,with a lesion detection concordance rate of 96.3%and an SUVmax error of 3.5%±1.2%.In the validation set,the mean effective dose(EDPET)was significantly lower than that in the pre-optimization training set for all body weight subgroups(P<0.05).Conclusion:The weight-stratified radiation dose optimization system based on shortened bed-dwell time can reduce the 18F-FDG radiation dose for patients weighing>70 kg while maintaining lesion detection rates,thereby lowering the radiation exposure level in adult tumor patients.