The application and challenges of clinical PD-PDT in the head and neck region: a short review.

We review current clinical applications of photodiagnosis (PD) and photodynamic therapy (PDT) in the head and neck field and highlight the actual status, problems, challenges as well as the future of this emerging treatment modality. In recent years literature presented input from many new developments and their applications. This is due to better awareness and developing knowledge about PD-PDT from the clinical staff, both nurses and doctors. But it is also a result of improved drug and hardware development such as lasers, LEDs and related optical devices. Current photo-medical applications in the head and neck region range from diagnostics, treatment of premalignant and malignant lesions, aesthetic and cosmetic applications to the ever expanding anti-microbial applications. Although treatment of premalignant and early malignant lesions of the oropharyngeal cavity have long been the favourite lesions to treat with PDT patients with unsalvageable tumors have also been responding remarkably well to PDT, adding significant quality of life. There is growing interest in anti-microbiological PDT and recent progress has shown that this application is able to significantly reduce the number or even eradicate specific microbial pathogens. During many surgical treatments better control of microbiological activity through PDT may lead to a better outcome. Despite progressive development in this field a few problems remain: prolonged phototoxicity, limited penetration of the photosensitizer and light, inadequate specificity, PDT-related pain as well as the lack of uniformly accepted protocols both for light application as well as photosensitizers. Recent studies have shown that PDT based pain can be separated from other forms of pain, offering hope that a specific management of pain will be possible. If PDT will become fully accepted by patients and doctors we must care about the negative factors such as pain and prolonged phototoxicity.