Clinical photodynamic therapy: The evolution of photodynamic therapy treatment of head and neck cancer

Abstract

The modern era of photodynamic therapy (PDT) treatment of human cancer began in earnest in 1978, with the publication by Dougherty et al. of the first large series of humans with refractory or recurrent skin cancers successfully treated with PDT using HpD (Photofrin). The first human series of head and neck cancer patients successfully treated with PDT (Photofrin) was published in 1985, by Keller et al. Since that time, numerous clinical investigators around the world have treated thousands of head and neck cancer patients with PDT in clinical trials. These head and neck cancer PDT clinical trials enrolled patients with various stages of disease, and locations of the tumor and were treated using a variety of photosensitizers. Head and neck cancer PDT treatments were performed as the primary treatment with the intent to cure, as a late-stage treatment for palliation of the tumor, or as an adjuvant or neoadjuvant treatment in combination with surgery, radiation, chemotherapy and most recently immunotherapy. Over the past five decades, head and neck cancer PDT has evolved as newer and more targeted photosensitizers became available for clinical use, as well as advances in laser and fiberoptic technologies allowing for the activating light to be successfully and more easily delivered deep into large invasive tumors. In addition, PDT can be accurately delivered using endoscopic, robotic, CT, ultrasound and MRI guidance thereby specifically targeting the tumor and reducing treatment morbidity. Significant progress has been achieved in the ease of use and treatment efficacy of head and neck cancer PDT in various stages of the disease.