We demonstrate that Se administration in our AIT patient's cohort does not induce significant immunological changes, either in terms of cytokine production patterns of peripheral T lymphocytes or of TPOAb levels. Our data suggest that AIT patients with moderate disease activity (in terms of TPOAb and cytokine production patterns) may not (equally) benefit as patients with high disease activity.

Rationale: Novel radiopharmaceuticals for positron emission tomography (PET) are evaluated for the diagnosis of biochemically recurrent prostate cancer (BCR PC). Here, we compare the gastrin releasing peptide receptors (GRPR) -targeting 68 Ga-RM2 with the prostate specific membrane antigen (PSMA) -targeting 68 Ga-PSMA11 and 18 F-DCFPyL.Methods: Fifty patients had both 68 Ga-RM2 PET/MRI and 68 Ga-PSMA11 PET/CT (n=23) or 18 F-DCFPyL PET/CT (n=27) at an interval ranging from 1 to 60 days (mean±SD: 15.8±17.7).Maximum standardized uptake values (SUV max ) were collected for all lesions.Results: RM2 PET was positive in 35 and negative in 15 of the 50 patients. PSMA PET was positive in 37 and negative in 13 of the 50 patients. Both scans detected 70 lesions in 32 patients.Forty-three lesions in 18 patients were identified only on one scan: 68 Ga-RM2 detected 7 more lesions in 4 patients, while PSMA detected 36 more lesions in 13 patients.Conclusions: 68 Ga-RM2 remains a valuable radiopharmaceutical even when compared with the more widely used 68 Ga-PSMA11/ 18 F-DCFPyL in the evaluation of BCR PC. Larger studies are needed to verify that identifying patients for whom these two classes of radiopharmaceuticals are complementary may ultimately allow for personalized medicine.

18 F-DCFPyL (2-(3-{1-carboxy-5-[(6-18 F-fluoropyridine-3-carbonyl)amino]-pentyl}-ureido)-pentanedioic acid) is a promising PET radiopharmaceutical targeting prostate-specific membrane antigen (PSMA). We present our experience with this single-academic-center prospective study evaluating the positivity rate of 18 F-DCFPyL PET/CT in patients with biochemical recurrence (BCR) of prostate cancer (PC). Methods: We prospectively enrolled 72 men (52-91 y old; mean ± SD, 71.5 ± 7.2) with BCR after primary definitive treatment with prostatectomy (n 5 42) or radiotherapy (n 5 30). The presence of lesions compatible with PC was evaluated by 2 independent readers. Fifty-nine patients had scans concurrent with at least one other conventional scan: bone scanning (24), CT (21), MR (20), 18 F-fluciclovine PET/CT (18), or 18 F-NaF PET (14). Findings from 18 F-DCFPyL PET/CT were compared with those from other modalities. Impact on patient management based on 18 F-DCFPyL PET/CT was recorded from clinical chart review. Results: 18 F-DCFPyL PET/CT had an overall positivity rate of 85%, which increased with higher prostate-specific antigen (PSA) levels (ng/mL): 50% (PSA , 0.5), 69% (0.5 # PSA , 1), 100% (1 # PSA , 2), 91% (2 # PSA , 5), and 96% (PSA $ 5). 18 F-DCFPyL PET detected more lesions than conventional imaging. For anatomic imaging, 20 of 41 (49%) CT or MRI scans had findings congruent with 18 F-DCFPyL, whereas 18 F-DCFPyL PET was positive in 17 of 41 (41%) cases with negative CT or MRI findings. For bone imaging, 26 of 38 (68%) bone or 18 F-NaF PET scans were congruent with 18 F-DCFPyL PET, whereas 18 F-DCFPyL PET localized bone lesions in 8 of 38 (21%) patients with negative results on bone or 18 F-NaF PET scans. In 8 of 18 (44%) patients, 18 F-fluciclovine PET had located the same lesions as did 18 F-DCFPyL PET, whereas 5 of 18 (28%) patients with negative 18 F-fluciclovine findings had positive 18 F-DCFPyL PET findings and 1 of 18 (6%) patients with negative 18 F-DCFPyL findings had uptake in the prostate bed on 18 F-fluciclovine PET. In the remaining 4 of 18 (22%) patients, 18 F-DCFPyL and 18 F-fluciclovine scans showed different lesions. Lastly, 43 of 72 (60%) patients had treatment changes after 18 F-DCFPyL PET and, most noticeably, 17 of these patients (24% total) had lesion localization only on 18 F-DCFPyL PET, despite negative results on conventional imaging. Conclusion: 18 F-DCFPyL PET/CT is a promising diagnostic tool in the work-up of biochemically recurrent PC, given the high positivity rate as compared with Food and Drug Administration-approved currently available imaging modalities and its impact on clinical management in 60% of patients.

Targeting tumor-expressed receptors using selective molecules for diagnostic, therapeutic, or both diagnostic and therapeutic (theragnostic) purposes is a promising approach in oncologic applications. Such approaches have increased significantly over the past decade. Peptides such as gastrin-releasing peptide receptors targeting radiopharmaceuticals are small molecules with fast blood clearance and urinary excretion. They demonstrate good tissue diffusion, low immunogenicity, and highly selective binding to their target cell-surface receptors. They are also easily produced. Gastrin-releasing peptide receptors, part of the bombesin family, are overexpressed in many tumors, including breast and prostate cancer, and therefore represent an attractive target for future development.

(11)C-Methionine PET/CT is a useful complementary imaging technique to localize parathyroid adenoma or carcinoma in (99m)Tc-MIBI SPECT/CT-negative patients.