RT Journal Article
SR Electronic
T1 c-MET Receptor–Targeted Fluorescence on the Road to Image-Guided Surgery in Penile Squamous Cell Carcinoma Patients
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 51
OP 56
DO 10.2967/jnumed.120.261864
VO 63
IS 1
A1 Hielke M. de Vries
A1 Elise Bekers
A1 Matthias N. van Oosterom
A1 M. Baris Karakullukcu
A1 Henk G. van
A1 der Poel
A1 Fijs W.B. van Leeuwen
A1 Tessa Buckle
A1 Oscar R. Brouwer
YR 2022
UL http://jnm.snmjournals.org/content/63/1/51.abstract
AB In penile squamous cell carcinoma (pSCC), primary surgery aims to obtain oncologically safe margins while minimizing mutilation. Surgical guidance provided by receptor-specific tracers could potentially improve margin detection and reduce unnecessary excision of healthy tissue. Here, we present the first results of a prospective feasibility study for real-time intraoperative visualization of pSCC using a fluorescent mesenchymal–epithelial transition factor (c-MET) receptor targeting tracer (EMI-137). Methods: EMI-137 tracer performance was initially assessed ex vivo (n = 10) via incubation of freshly excised pSCC in a solution containing EMI-137 (500 nM). The in vivo potential of c-MET targeting and intraoperative tumor visualization was assessed after intravenous administration of EMI-137 to 5 pSCC patients scheduled for surgical resection using a cyanine-5 fluorescence camera. Fluorescence imaging results were related to standard pathologic tumor evaluation and c-MET immunohistochemistry. Three of the 5 in vivo patients also underwent a sentinel node resection after local administration of the hybrid tracer indocyanine green– 99mTc-nanocolloid, which could be imaged using a near-infrared fluorescence camera. Results: No tracer-related adverse events were encountered. Both ex vivo and in vivo, EMI-137 enabled c-MET–based tumor visualization in all patients. Histopathologic analyses showed that all pSCCs expressed c-MET, with expression levels of at least 70% in 14 of 15 patients. Moreover, the highest c-MET expression levels were seen on the outside rim of the tumors, and a visual correlation was found between c-MET expression and fluorescence signal intensity. No complications were encountered when combining primary tumor targeting with lymphatic mapping. As such, simultaneous use of cyanine-5 and indocyanine green in the same patient proved to be feasible. Conclusion: Fluorescence imaging of c-MET receptor– expressing pSCC tumors after intravenous injection of EMI-137 was shown to be feasible and can be combined with fluorescence-based lymphatic mapping. This combination is unique and paves the way toward further development of this surgical guidance approach.