RT Journal Article SR Electronic T1 Detection of Recurrent Prostate Cancer Using 68Ga-RM2 PET/MRI in Patients with Negative Conventional Imaging JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 711 OP 711 VO 58 IS supplement 1 A1 Harrison, Caitlyn A1 Sonni, Ida A1 Loening, Andreas A1 Vasanawala, Shreyas A1 Iagaru, Andrei YR 2017 UL http://jnm.snmjournals.org/content/58/supplement_1/711.abstract AB 711Objectives: 68Ga-labeled DOTA-4-amino-1-carboxymethyl-piperidine-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2 (68Ga-RM2, formerly known as 68Ga-Bombesin or BAY86-7548) is a synthetic bombesin receptor antagonist that targets gastrin-releasing peptide receptors (GRPr). GRPr are highly overexpressed in several human tumors, including prostate cancer (PC). Because of their low expression in BPH and inflammatory prostatic tissues, imaging GRPr has potential advantages over current choline- and acetate-based radiotracers.Methods: We enrolled 31 men with BCR PC, 59-83 year-old (mean±SD: 68.7±6.8) in an IRB-approved prospective study. Imaging started at 40-69 minutes (mean±SD: 50.2±7.1) after injection of 3.6-4.1 mCi (mean±SD: 3.8±0.2) of 68Ga-RM2 using a time-of-flight enabled simultaneous PET/MRI scanner. MRI sequences consisted of T1-weighted, T2-weighted and DWI. SUVmax and SUVmean measurements were recorded in normal tissues and areas of uptake outside the expected physiologic biodistribution.Results: All patients had rising PSA (range: 0.3-36.4 ng/mL; mean±SD: 7.4±8.1) and non-contributory CI (CT, MRI, 99mTc MDP bone scan). High 68Ga-RM2 uptake (SUVmax: 12.7 ± 7.8 [range: 2.6 - 33.5], SUVmean: 5.7 ± 2.5 [range: 1.7 - 10.8]) corresponded to pelvic lymph nodes (8 patients), retroperitoneal lymph nodes (5 patients), prostate bed (3 patients), seminal vesicle (2 patients), supraclavicular lymph node (2 patients), mesenteric lymph nodes (1 patient), mediastinal lymph node (1 patient), liver (1 patient), lung (1 patient) and bone marrow (1 patient). 68Ga-RM2 PET findings were compatible with recurrent prostate cancer in 21 of the 31 participants. MRI identified findings compatible with recurrent prostate cancer in 10 of the 31 patients (lymph nodes in 7 patients, prostate bed in 1 patient, lung in 1 patient and bone marrow in 1 patient). Findings were confirmed by biopsy in 7/31 cases (22.6%) or clinical follow-up in 24/31 cases (77.4%).Conclusion: 68Ga-RM2 is a promising PET radiopharmaceutical for localization of disease in participants with BCR PC and non-contributory conventional imaging. Research Support: Piramal Imaging, GmbH