PRIMARY OBJECTIVES: * To test the accuracy of image-guided fluorescence to detect residual disease. (Phase I) - completed * To determine the safety of intraoperative PDT after fluorescence-guided surgery in patients with loco-regionally advanced or recurrent colorectal cancer undergoing surgery. (Phase I) - completed * To determine the potential efficacy of intraoperative PDT (after image-guided fluorescence surgery). (Phase II) - SECONDARY OBJECTIVES: * To assess the relationship between disease free survival and changes in levels of carcinoembryonic antigen (CEA) and circulating tumor DNA (ctDNA). (Phase II) * To assess rate of recurrence by using standard-of-care computed tomography (CT) and/or magnetic resonance imaging (MRI). (Phase II) OUTLINE: Patients receive aminolevulinic acid orally (PO) 2 to 4 hours prior to standard of care (SOC) surgery.
Patients then undergo image-guided fluorescence 5-10 minutes post surgery, and intraoperative PDT 15-45 minutes post surgery. Patients also undergo computed tomography (CT) or magnetic resonance imaging (MRI) during screening and on follow up. Patients also undergo blood sample collection throughout the trial. After completion of study treatment, patients are followed up at 3 months, 24 weeks, and every 3 to 6 months for 3 years.
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).