[Photodynamic therapy in the gastrointestinal tract. Possibilities and limits]

Photodynamic therapy (PDT) is characterized by the extensive selective accumulation of a photoactive agent, the photosensitizer, in malignant or precancerous tumour cells. The photoactive compound is activated by light beam of a specific wavelength and causes cell death. A significant proportion of patients with gastrointestinal malignancies cannot undergo curative treatment, as either the cancer is too advanced or the patient's general constitution is too poor to allow invasive strategies. In such cases, PDT has already proven to be a promising therapeutic modality for selected dysplasias and malignancies in the gastrointestinal tract.

A retrospective review of the literature was performed in order to determine the experience gained with PDT and to assess its clinical value in the curative and palliative management of gastrointestinal neoplasms.

PDT seems to be an adequate treatment for selected forms of early cancer and small lesions of the GI tract or for small residual areas after the tumour has been debulked by other techniques (e.g. limited surgical resection, thermal ablation). Especially for patients who refuse or are ineligible for conventional surgery, PDT offers promising results compared to currently accepted clinical approaches.

As a primary or adjuvant mode for either curative or palliative treatment of gastrointestinal neoplasms, PDT is a potentially effective, minimally invasive therapeutic modality. However, further clinical assessment by means of comparative, standardized studies is essential to the definition of its role in oncology.