Due to the severe complications of expanded lymph node dissection (ePLND) and the limited detection rates of metastatic positive lymph nodes, targeted sentinel lymph node detection was considered to be a promising alternative to ePLND. This study aimed to evaluate the effectiveness and safety of fluorescent targeting nucleic acid aptamers for lymph node dissection during robot-assisted radical prostatectomy (RARP).

In this study, the prostate cancer cell-specific nucleic acid aptamer Wy-5a was covalently combined with the fluorescent contrast agent indocyanine green (ICG) to develop a prostate cancer-specific fluorescent targeting nucleic acid agent Wy-5a-ICG. Compared with the commercial ICG, optical properties and physical and chemical characteristics of Wy-5a-ICG were analyzed. The specificity and safety of Wy-5a-ICG binding to prostate cancer cells were identified in vivo and in vitro. After institutional review board approval, in April 2021, one patient with intermediate-risk prostate cancer in our hospital was enrolled, with a Briganti nomogram score of 5.4%, and 10 mg fluorescent agent was injected the night before surgery. During the operation, the pelvic fluorescent lymph node (FLN) as a sentinel lymph node was carefully detected in the dark field, and the FLNs sites were recorded. FLNS were removed and submitted for pathological examination. The fluorescence of the gland was detected and recorded in the dark field invasion during prostatectomy.

The physical and chemical properties of Wy-5a-ICG and ICG were similar, and the optical characteristics were identical. MTT assay and toxicity test confirmed that Wy-5a-ICG was safe in vitro and in vivo. The operation was completed successfully, and there were no complications. Pathological showed negative margins, and a total of 2 lymph nodes were dissected, of which 1 was positive metastasis.

Wy-5a-ICG aptamer can be used as an efficient tool for prostate cancer imaging. The results suggest that Wy-5a-ICG can provide real-time targeted sentinel lymph node dissection during RARP.