Safety and Feasibility of PARP1/2 Imaging with 18F-PARPi in Patients with Head and Neck Cancer

Purpose: We performed a first-in-human clinical trial. The aim of this study was to determine safety and feasibility of PET imaging with F-18-PARPi in patients with head and neck cancer. Patients and Methods: Eleven patients with newly diagnosed or recurrent oral and oropharyngeal cancer were injected with F-18-PARPi (331 +/- 42 MBq), and dynamic PET/CF imaging was performed between 0 and 25 minutes postinjection. Static PET/CT scans were obtained at 30, 60, and 120 minutes postinjection. Blood samples for tracer concentration and metabolite analysis were collected. Blood pressure, ECG, oxygen levels, clinical chemistry, and complete blood count were obtained before and after tracer administration. Results F-18-PARPi was well-tolerated by all patients without any safety concerns. Of the 11 patients included in the analysis, F-18-PARPi had focal uptake in all primary lesions (n = 10, SUVmax, = 2.8 +/- 1.2) and all F-18-FDG-positive lymph nodes (n = 34). F-18-PARPi uptake was seen in F-18-FDG-negative lymph nodes of 3 patients (n = 6). Focal uptake of tracer in primary and metastatic lesions was corroborated by CT alone or in combination with F-18-FDG. The overall effective dose with F-18-PARPi PET was 3.9 mSv - 5.2 mSv, contrast was high [SUVmax(lesion)/SUVmax(trapezius muscle) = 4.5] and less variable than F-18-FDG when compared with the genioglossus muscle (1.3 vs. 6.0, P = 0.001). Conclusions Imaging of head and neck cancer with F-18-PARPi is feasible and safe. F-18-PARPi detects primary and metastatic lesions, and retention in tumors is longer than in healthy tissues.