Discordant Molecular Imaging Findings with 2-[F]FDG and [Ga]Ga-PSMA PET/CT in a Patient with Both Bladder and Prostate Cancer.

The prevalence of double primary prostate and bladder cancer is not uncommon. Though both share a common pathway of malignant transformation, they bear to differ in the case of 2-[F]FDG PET/CT and [Ga]Ga-PSMA uptake. We present a case of double primary cancer involving the bladder and prostate, where the prostatic primary showed intense [Ga]Ga-PSMA uptake with non-avid skeletal and pulmonary metastases, which showed intense 2-[F]FDG uptake, thus showing discordance due to different clonal origins.

18 F-FES Uptake in Radiation Pneumonitis.

18 F-FDG uptake in radiation pneumonitis is well documented; however, the same is less so for 18 F-floroestradiol (FES), which specifically binds to the estrogen receptors in vivo. We observed increased FES uptake in the right lung of an estrogen receptor positive breast cancer patient who had undergone right modified radical mastectomy followed by radiation therapy to chest wall. The possibility of FES uptake in radiation pneumonitis must therefore be kept in mind while interpreting FES PET.