The main reasons for the relatively low sensitivity of PSMA-targeted imaging of PCa are (i) the absence of or insufficient PSMA expression in about 10% of primary PCa, (ii) presence of lesions with downregulated PSMA due to therapy resistance (e.g., neuroendocrine-differentiated PCa), (iii) difficulties in the detection of lesions below 5 mm (80% of lymph node metastases are smaller than 8 mm), and (iv) lesion location in the proximity of the urinary bladder [4,10]. Here, FOLH1 is linked to metastatic malignant neoplasm in the lymph nodes.