Practical aspects of photodynamic therapy for superficial bladder carcinoma

Most clinicians equate laser use with direct thermal ablation of tissue, but the precise spatial and temporal control of laser energy has made possible a number of diagnostic and therapeutic applications for these unique light sources that do not involve nonspecific thermal destruction of tissue. One such application is the detection and treatment of tissue with compounds that absorb specific types of light, known as photodynamic therapy (PDT). This article examines the practical aspects of PDT for the treatment of superficial bladder carcinoma with an emphasis on dosimetry. The results presented are encouraging and suggest that patient who have diffuse superficial bladder carcinoma refractive to standard treatment methods should be given the benefit of whole bladder PDT before commitment to radical extirpative surgery. Close attention to dosimetry will be required. PDT remains experimental at this stage; it has been approved for general use only in Canada, though filings with regulatory agencies in both the United States and Europe are anticipated in the near future.