PT  - JOURNAL ARTICLE
AU  - Darr, Christopher
AU  - Harke, Nina
AU  - Radtke, Jan Philipp
AU  - Yirga, Leubet
AU  - Kesch, Claudia
AU  - Grootendorst, Maarten
AU  - Fendler, Wolfgang
AU  - Fragoso Costa, Pedro
AU  - Rischpler, Christoph
AU  - Praus, Christine
AU  - Haubold, Johannes
AU  - Reis, Henning
AU  - Hager, Thomas
AU  - Herrmann, Ken
AU  - Binse, Ina
AU  - Hadaschik, Boris
TI  - Intraoperative <sup>68</sup>Gallium-PSMA Cerenkov Luminescence Imaging for surgical margins in radical prostatectomy – a feasibility study
AID  - 10.2967/jnumed.119.240424
DP  - 2020 Feb 01
TA  - Journal of Nuclear Medicine
PG  - jnumed.119.240424
4099  - http://jnm.snmjournals.org/content/early/2020/02/13/jnumed.119.240424.short
4100  - http://jnm.snmjournals.org/content/early/2020/02/13/jnumed.119.240424.full
AB  - Objective: To assess the feasibility and accuracy of Cerenkov Luminescence Imaging (CLI) for assessment of surgical margins intraoperatively during radical prostatectomy (RPE). Methods: A single centre feasibility study included 10 patients with high-risk primary prostate cancer (PC). 68Ga-PSMA PET/CT scans were performed followed by RPE and intraoperative CLI of the excised prostate. In addition to imaging the intact prostate, in the first two patients the prostate gland was incised and imaged with CLI to visualise the primary tumour. We compared the tumour margin status on CLI to postoperative histopathology. Measured CLI intensities were determined as tumour to background ratio (TBR). Results: Tumour cells were successfully detected on the incised prostate CLI images as confirmed by histopathology. 3 of 10 men had histopathological positive surgical margins (PSMs), and 2 of 3 PSMs were accurately detected on CLI. Overall, 25 (72%) out of 35 regions of interest (ROIs) proved to visualize a tumour signal according to standard histopathology. The median tumour radiance in these areas was 11301 photons/s/cm2/sr (range 3328 - 25428 photons/s/cm2/sr) and median TBR was 4.2 (range 2.1 – 11.6). False positive signals were seen mainly at the prostate base with PC cells overlaid by benign tissue. PSMA-immunohistochemistry (PSMA-IHC) revealed strong PSMA staining of benign gland tissue, which impacts measured activities. Conclusion: This feasibility showed that 68Ga-PSMA CLI is a new intraoperative imaging technique capable of imaging the entire specimen’s surface to detect PC tissue at the resection margin. Further optimisation of the CLI protocol, or the use of lower-energetic imaging tracers such as 18F-PSMA, are required to reduce false positives. A larger study will be performed to assess diagnostic performance.