Hybrid tracers and devices for intraoperative imaging: the future for radioguided surgery?

Radioguided surgery (RS) allows surgeons to identify tissues of interest that were preoperatively or intraoperatively marked with radiotracers. This discipline has seen major changes related to the development of new tracers, instrumentation and software. The goal of this review is to comment on current development and perspectives in the RS field. The review is based on published papers that highlight the role of RS and explore current advances such as the Guided intraOperative Scintigraphic Tumour Targeting (GOSTT) concept, which established the see, open and see strategy and propose a new one, Guided Hybrid intraOperative Specific Targeting (GHOST). We examine the development of radioactive, fluorescent and hybrid tracers and corresponding instrumentation and software to detect them and suggest ways in which these developments could be integrated. The role of hybrid tracers in RS, in particular Tc-99m nanocolloid indocyanine green on sentinel node procedures, is highlighted. Labeled specific targeted peptides, antibodies and nanostructures will allow better preoperative diagnosis and intraoperative localization of tissue of interest. Photodynamic therapy could be applied during surgery to eliminate residual tumoral tissue. In the follow up, patients could be considered for treatment with targeted radiotherapy. RS has moved from open surgery to laparoscopic and robotic surgery. In each of them it is possible to add fluorescent, radioactive and hybrid modules able to detect labeled tissue of interest, while preserving healthy ones. As we have seen, RS is advancing through an interdisciplinary collaboration that will provide surgeons with new tools to improve surgical outcomes.