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 89 men with biochemically recurrent PC from May 2017 to Sep 2020, 45-81 year-old (mean +/- standard deviation (SD): 67.8 +/- 7.1). Imaging started at 40-89 minutes (mean +/- SD: 51.1 +/- 11.8) after injection of 113.8-151.3 MBq (mean +/- SD: 139.7 +/- 5.1) 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; mean +/- SD: 5.3 +/- 14.0) and negative CI (CT or MRI, and 99mTc MDP bone scan) prior to enrollment. The observed 68Ga-RM2 PET detection rate was 69.7%. PSA ranged 0.2-17.2 (mean +/- SD: 2.0 +/- 3.7) in patients with negative scans and 0.2-124.0 (mean +/- SD: 6.8 +/- 3.1) 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, 2020
- Accession Number
- AD1126816
Entities
People
- Andrei Iagaru
Organizations
- Stanford University