Physiological FAP-activation in a postpartum woman observed in oncological FAPI-PET/CT

Purpose!#!One therapy option for prostate cancer patients with bone metastases is the use of [!##!Methods!#!Multiple blood samples from nine prostate cancer patients were collected before and after administration of [!##!Results!#!The absorbed doses to the blood were less than 6 mGy up to 4 h after administration and maximally 16 mGy in total. Up to 4 h after administration, the α-track frequency was significantly increased relative to baseline and correlated with the absorbed dose to the blood in the dose range < 3 mGy. In most of the late samples (24 h - 4 weeks after administration), the α-track frequency remained elevated.!##!Conclusion!#!The γ-H2AX+53BP1 assay is a potent method for detection of α-particle-induced DNA damages during treatment with or after accidental incorporation of radionuclides even at low absorbed doses. It may serve as a biomarker discriminating α- from β-emitters based on damage geometry.