RT Journal Article SR Electronic T1 Differentiation of Discordant Lesions on Dual-Tracer PET/CT (68Ga-PSMA-11 and 18F-FDG) in Prostate Carcinoma: Diagnosis of Second Primary Malignancies JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP jnmt.123.265779 DO 10.2967/jnmt.123.265779 A1 Chalikandy, Ashwini A1 Yadav, Subhash A1 Basu, Sandip YR 2023 UL http://tech.snmjournals.org/content/early/2023/08/16/jnmt.123.265779.abstract AB We present 2 cases of metastatic castration-resistant prostate carcinoma with discordant lesions on dual-tracer PET/CT (68Ga-PSMA-11 and 18F-FDG PET/CT), which on subsequent histopathologic evaluation revealed second primary malignancies of combined hepatocellular carcinoma and cholangiocarcinoma and poorly differentiated squamous cell carcinoma. These case illustrations emphasize the need to evaluate discordant lesions on dual-tracer PET/CT, which can lead to early diagnosis of second primary malignancies and thereby can provide better management in these patients.