Intraoperative Imaging Techniques to Support Complete Tumor Resection in Partial Nephrectomy

With more complex kidney tumors treated by nephron-sparing surgery (NSS), complete tumor resection is becoming increasingly challenging. Intraoperative imaging may improve the establishment of negative surgical margins.

To discuss intraoperative imaging techniques that may help achieve complete tumor resection in NSS of renal tumors.

PubMed was searched for English articles on intraoperative imaging during NSS of renal cell carcinoma published after 2005, and a reference search of retrieved articles was performed.

Included studies reported about ultrasonography, fluorescence imaging, augmented reality, optical coherence tomography, and ex vivo magnetic resonance imaging (MRI). The number of patients included in these studies is limited, and randomized controlled trials have not been performed. Ultrasonography is a well-established technique to assess tumor localization and may be used to evaluate surgical margins of the resected specimen. Fluorescence imaging with indocyanine green may help differentiate tumor from normal kidney tissue. It is yet unclear whether fluorescence imaging can detect positive surgical margins. Augmented reality is best studied in robotic laparoscopic surgery, and may be useful for tumor localization and resection, if the problem of tissue deformation during surgery can be solved. More results have to be awaited about optical coherence tomography and ex vivo MRI.

Ultrasonography is a widely used technique to assist the surgeon in partial nephrectomy nowadays, while the use of fluorescence imaging and augmented reality is emerging. Although various techniques can be used during NSS, the added value of intraoperative imaging to support negative surgical margins remains to be demonstrated.

In this review, we discuss the value of various intraoperative imaging techniques that may help a urologist achieve complete tumor resection in nephron-sparing surgery for kidney tumors. Ultrasonography, fluorescence imaging, and augmented reality have been studied best, but their added value needs further investigation.