Local and metastatic relapses of
prostate cancer often occur following attempted curative resection of the primary
tumor, and up to 66% of local recurrences are associated with positive margins. Therefore, technologies that can improve the visualization of
tumor margins and adjuvant
therapies to ablate remaining
tumor tissues are needed during surgical resection of prostate
adenocarcinoma. Photodynamic agents have the potential to combine both fluorescence for
image-guided surgery (IGS) and
photodynamic therapy (
PDT) to resect and ablate
cancer cells. The objective of this study was to determine the utility of a targeted
PDT agent for IGS and adjuvant
PDT. Using a previously developed prostate-specific membrane
antigen (PSMA)-targeted
PDT agent, PSMA-1-Pc413, we showed that PSMA-1-Pc413 selectively highlighted PSMA-expressing
tumors, allowing IGS and more complete
tumor resection compared with white light surgery. Subsequent
PDT further reduced
tumor recurrence and extended animal survival significantly. This approach also enabled identification of
tumor cells in lymph nodes. In summary, this study presents a potential new treatment option for patients with
prostate cancer undergoing surgery, which improves
tumor visualization and discrimination during surgery, including identification of
cancer in lymph nodes. SIGNIFICANCE: These findings present a photodynamic agent that can be used for both
photodynamic therapy and
image-guided surgery, allowing better visualization of
tumor margins and elimination of
residual tumor tissues.