Intra-abdominal photodynamic therapy: from theory to feasibility

Photodynamic therapy is a new anticancer technique, directed at the selective destruction of neoplastic tissue, which has been used in the treatment of superficial or intraluminal lesions. The technique has now reached the stage where it can be considered in the peroperative management of gastrointestinal tumours, for example in an attempt to eradicate micrometastases in the tissue around the primary tumour or in residual lymph nodes after curative resection. Many practical problems remain to be solved, such as the pharmacokinetics of photosensitizers, the dosimetry of illumination and the sensitivity of intra-abdominal organs. An experimental and clinical evaluation is in progress to assess the feasibility of photodynamic therapy in surgical practice.