RT Journal Article
SR Electronic
T1 Utility of <sup>64</sup>Cu-Sarcophagine-Bombesin PET/CT in Men with Biochemically Recurrent Prostate Cancer and Negative or Equivocal Findings on <sup>68</sup>Ga-PSMA-11 PET/CT
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP jnumed.124.267881
DO 10.2967/jnumed.124.267881
A1 Li, Sherrington
A1 Nguyen, Andrew
A1 Counter, William
A1 John, Nikeith C.
A1 De Leon, Jeremiah
A1 Hruby, George
A1 Joshua, Anthony M.
A1 Stricker, Phillip
A1 Crumbaker, Megan
A1 Ayati, Narjess
A1 Chan, Lyn
A1 Sabahi, Zahra
A1 Swiha, Mina
A1 Kneebone, Andrew
A1 Wong, Keith
A1 Liu, Victor
A1 Sharma, Shikha
A1 Agrawal, Shikha
A1 Emmett, Louise M.
YR 2024
UL http://jnm.snmjournals.org/content/early/2024/08/08/jnumed.124.267881.abstract
AB Despite a high detection rate of 68Ga-prostate-specific membrane antigen (PSMA) PET/CT in biochemical recurrence (BCR) of prostate cancer, a significant proportion of men have negative 68Ga-PSMA-11 PET/CT results. Gastrin-releasing peptide receptor, targeted by the copper-chelated bombesin analog 64Cu-sarcophagine-bombesin (SAR-BBN) PET/CT, is also overexpressed in prostate cancer. In this prospective imaging study, we investigate the detection rate of 64Cu-SAR-BBN PET/CT in patients with BCR and negative or equivocal 68Ga-PSMA-11 PET/CT results. Methods: Men with confirmed adenocarcinoma of the prostate, prior definitive therapy, and BCR (defined as a prostate-specific antigen [PSA] level &gt; 0.2 ng/mL) with negative or equivocal 68Ga-PSMA-11 PET/CT results within 3 mo were eligible for enrollment. 64Cu-SAR-BBN PET/CT scans were acquired at 1 and 3 h after administration of 200 MBq of 64Cu-SAR-BBN, with further delayed imaging undertaken optionally at 24 h. PSA (ng/mL) was determined at baseline. All PET (PSMA and bombesin) scans were assessed visually. Images were read with masking of the clinical results by 2 experienced nuclear medicine specialists, with a third reader in cases of discordance. Accuracy was defined using a standard of truth that included biopsy confirmation, confirmatory imaging, or response to targeted treatment. Results: Twenty-five patients were enrolled. Prior definitive therapy was radical prostatectomy (n = 24, 96%) or radiotherapy (n = 1, 4%). The median time since definitive therapy was 7 y (interquartile range [IQR], 4–11 y), and the Gleason score was 7 or less (n = 15, 60%), 8 (n = 3, 12%), or 9 (n = 7, 28%). The median PSA was 0.69 ng/mL (IQR, 0.28–2.45 ng/mL). Baseline PSMA PET scans were negative in 19 patients (76%) and equivocal in 6 (24%). 64Cu-SAR-BBN PET–avid disease was identified in 44% (11/25): 12% (3/25) with local recurrence, 20% (5/25) with pelvic node metastases, and 12% (3/25) with distant metastases. The κ-score between readers was 0.49 (95% CI, 0.16–0.82). Patients were followed up for a median of 10 mo (IQR, 9–12 mo). Bombesin PET/CT results were true-positive in 5 of 25 patients (20%), false-positive in 2 of 25 (8%), false-negative in 7 of 25 (28%), and unverified in 11 of 25 (44%). Conclusion: 64Cu-SAR-BBN PET/CT demonstrated sites of disease recurrence in 44% of BCR cases with negative or equivocal 68Ga-PSMA-11 PET/CT results. Further evaluation to confirm diagnostic benefit is warranted.