Abstract
1910
Objectives [18F]DCFBC is a promising PET imaging agent for prostate cancer that targets the prostate-specific membrane antigen (PSMA). Whole body biodistribution analysis was performed on the initial patients of an ongoing Phase 1 clinical trial.
Methods Three male patients with documented prostate cancer were injected with between 360 and 373 MBq of [18F]DCFBC and subsequently underwent serial whole body PET/CT imaging. A total of five PET series were acquired for each patient over an approximate 2.5 hour period. ROIs were drawn and time-activity curves were generated for multiple organs, including heart, lung, liver, kidney, bladder, small bowel, brain and bone.
Results The maximum %ID/g appeared within the bladder and contents in all patients and ranged between 0.01 and 0.02, with the peak occurring between 40 and 100 minutes post-injection. There was an initial rise in renal activity that subsequently decreased in concert with the heart contents. The brain demonstrated little uptake, consistent with the hydrophilic nature of [18F]DCFBC. Interestingly, the testes demonstrate a slow rise in activity over time before reaching a plateau after 60 minutes. The remaining organs show continual decreasing activity over time.
Conclusions Initial human biodistribution data indicate that the bladder and contents receive the highest %ID/g. In contrast, preclinical data with mice demonstrated that the kidneys received the highest %ID/g, followed by the bladder. Dose reduction strategies such as hydration and bladder catheterization may allow an increase in the injected dose if desired. Biodistribution with additional patients is ongoing with formal dosimetric analysis planned in the near future.
Research Support NCI R01CA13467