RT Journal Article SR Electronic T1 c-Met PET Imaging Detects Early-Stage Locoregional Recurrence of Basal-Like Breast Cancer JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 765 OP 770 DO 10.2967/jnumed.115.164384 VO 57 IS 5 A1 Appitha Arulappu A1 Mark Battle A1 Michel Eisenblaetter A1 Graeme McRobbie A1 Imtiaz Khan A1 James Monypenny A1 Gregory Weitsman A1 Myria Galazi A1 Susan Hoppmann A1 Patrycja Gazinska A1 Wulan Wulaningsih A1 Grethe Tang Dalsgaard A1 Sven Macholl A1 Tony Ng YR 2016 UL http://jnm.snmjournals.org/content/57/5/765.abstract AB Locoregional recurrence of breast cancer poses significant clinical problems because of frequent inoperability once the chest wall is involved. Early detection of recurrence by molecular imaging agents against therapeutically targetable receptors, such as c-Met, would be of potential benefit. The aim of this study was to assess 18F-AH113804, a peptide-based molecular imaging agent with high affinity for human c-Met, for the detection of early-stage locoregional recurrence in a human basal-like breast cancer model, HCC1954. Methods: HCC1954 tumor–bearing xenograft models were established, and 18F-AH113804 was administered. Distribution of radioactivity was determined via PET at 60 min after radiotracer injection. PET and CT images were acquired 10 d after tumor inoculation, to establish baseline distribution and uptake, and then on selected days after surgical tumor resection. CT images and caliper were used to determine the tumor volume. Radiotracer uptake was assessed by 18F-AH113804 PET imaging. c-Met expression was assessed by immunofluorescence imaging of tumor samples and correlated with 18F-AH113804 PET imaging results. Results: Baseline uptake of 18F-AH113804, determined in tumor-bearing animals after 10 d, was approximately 2-fold higher in the tumor than in muscle tissue or the contralateral mammary fat pad. The tumor growth rate, determined from CT images, was comparable between the animals with recurrent tumors, with detection of tumors of low volume (<10 mm3) only possible by day 20 after tumor resection. 18F-AH113804 PET detected local tumor recurrence as early as 6 d after surgery in the recurrent tumor–bearing animals and exhibited significantly higher 18F-AH113804 uptake (in comparison to mammary fatty tissue), with a target-to-background (muscle) ratio of approximately 3:1 (P < 0.01). The c-Met expression of individual resected tumor samples, determined by immunofluorescence, correlated with the respective 18F-AH113804 imaging signals (r = 0.82, P < 0.05). Conclusion: 18F-AH113804 PET provides a new diagnostic tool for the detection of c-Met–expressing primary tumor and has potential utility for the detection of locoregional recurrence from an early stage.