Precise navigation surgery of tumours in the lung in mouse models enabled by in situ fluorescence labelling with a killer-reporter adenovirus

Background: Current methods of image-guided surgery of tumours of the lung mostly rely on CT. A sensitive procedure of selective tumour fluorescence labelling would allow simple and high-resolution visualisation of the tumour for precise surgical navigation. Methods: Human lung cancer cell lines H460 and A549 were genetically transformed to express red fluorescent protein (RFP). Tumours were grown subcutaneously for each cell line and harvested and minced for surgical orthotopic implantation on the left lung of nude mice. Tumour growth was measured by fluorescence imaging. After the tumours reached 5 mm in diameter, they were injected under fluorescence guidance with the telomerase-dependent green fluorescent protein (GFP)-containing adenovirus, OBP-401. Viral labelling of the lung tumours with GFP precisely colocalised with tumour RFP expression. Three days after administration of OBP-401, fluorescence-guided surgery (FGS) was performed. Results: FGS of tumours in the lung was enabled by labelling with a telomerase-dependent adenovirus containing the GFP gene. Tumours in the lung were selectively and brightly labelled. FGS enabled complete lung tumour resection with no residual fluorescent tumour. Conclusions: FGS of tumours in the lung is feasible and more effective than bright-light surgery.