CHAPTER 24: Head and Neck Photodynamic Therapy

Photodynamic therapy (PDT) has a very long history in the treatment of head and neck cancer. It is particularly appropriate as head and neck cancers are predominantly locoregional problems and conventional therapies often have devastating consequences in terms of function and aesthetics. In addition, as there is the potential for new tumours to arise in the upper aerodigestive tract, PDT offers a repeatable, function-preserving treatment that should be integrated into care pathways for head and neck cancer. In this chapter, the development of PDT in the head and neck is described, starting with a series of animal-based safety studies. Having understood the mechanisms of its effect, a series of prospective human studies is described that confirms the effectiveness and cost-effectiveness of the treatment. Initially, treatments were carried out by surface illumination, and while this was effective, there are clearly limits to the depth of treatment one can achieve. The subsequent development of image-guided treatments with more accurate targeting has raised the possibility of PDT as a first-line alternative to surgery and chemo-radiotherapy where there is significant comorbidity. There is a great deal of published data supporting a role for PDT in this area, but we have been very slow to adopt this in Europe and North America, and the reasons for this and the potential solutions are discussed. However, this is not the case in other parts of the world, where PDT is being developed for use in a number of conditions, in which it provides a reliable, cost-effective alternative to complex, expensive treatments such as ablative and reconstructive surgery or chemo-radiotherapy.