68Ga Bombesin PET/MRI in Patients with Biochemically Recurrent Prostate Cancer and Noncontributory Conventional Imaging
Abstract
Purpose: 68Ga-labeled DOTA-4-amino-1-carboxymethyl-piperidine-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2 (68Ga-RM2) is a synthetic bombesin receptor antagonist that targets gastrin-releasing peptide receptors (GRPr). GRPr proteins are highly overexpressed in several human tumors, including prostate cancer (PC). Methods: We enrolled 49 men with biochemically recurrent PC from May 2017 to Sep 2018, 59-79 year-old (meanstandard deviation (SD): 69.85.4). Imaging started at 40-89 minutes (meanSD: 56.328.6) after injection of 127.5-149.7 MBq (meanSD: 141.64.4) of 68Ga-RM2 using a time-of-flight (TOF)-enabled simultaneous positron emission tomography (PET) / magnetic resonance imaging (MRI) scanner. T1-weighted (T1w), T2-weighted (T2w) and diffusion-weighted images (DWI) were acquired. Results: All patients had rising prostate specific antigen (PSA) (range: 0.2-124.0 ng/mL; meanSD: 6.619.3) and negative CI (CT or MRI, and 99mTc MDP bone scan) prior to enrollment. The observed 68Ga-RM2 PET detection rate was 73.5%. 68Ga-RM2 PET identified recurrent PC in 36 of the 49 participants. PSA ranged 0.2-9.1 (meanSD: 1.92.5) in patients with negative scans and 0.2-124.0 (meanSD: 8.220.4) in patients with positive scans. Conclusions: 68Ga-RM2 PET can be used for assessment of GRPr expression in patients with biochemically recurrent PC. High uptake in multiple areas compatible with cancer lesions suggests that 68Ga-RM2 is a promising PET radiopharmaceutical for localization of disease in participants with biochemically recurrent PC and negative conventional imaging.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2018
- Accession Number
- AD1073045
Entities
People
- Andrei Iagaru
Organizations
- Stanford University