Fluorescence Image Guided Surgery Followed by Intraoperative Photodynamic Therapy for Improving Local Tumor Control in Patients With Locally Advanced or Recurrent Colorectal Cancer

\*As of June 2026- Phase I has been completed and we are now in Phase II. This phase I/II trial studies the side effects and how well fluorescence image guided surgery followed by intraoperative photodynamic therapy for improving local tumor control in patients with colorectal cancer that has spread to nearby tissue or lymph nodes (locally advanced) or that has come back after a period of improvement (recurrent). Fluorescence image guided surgery uses a drug named aminolevulinic acid hydrochloride. Aminolevulinic acid hydrochloride is a photosensitizing agent, meaning that is activated by light and, is converted to another drug in cancer cells more than in normal cells. The converted drug emits fluorescence red light when activated with low power blue light. It is used to assist the surgeon to see cancer cells and small cancerous tissue that may have been missed during routine surgery. In addition to emitting fluorescence light, the converted drug in the cancer cells and tissue can be activated with red laser light to kill cancer cells. This procedure is called photodynamic therapy (PDT). Performing fluorescence image guided surgery followed by intraoperative photodynamic therapy after the surgical removal of the colorectal tumor before the surgical site will be closed may be effective and improve outcomes in patients with locally advanced or recurrent colorectal cancer.