Photoradiation therapy of head and neck cancer.

We have embarked upon a pilot study of photoradiation therapy (PRT) in the treatment of persistent or recurrent cancer of the head and neck, utilizing the photosensitizing agent, hematoporphyrin derivative (HPD). This treatment is based upon selective concentration of HPD within malignant tissue, with resultant necrosis upon illumination with light of the appropriate wavelength (640 nm). Patients entered in this trial have failed all forms of conventional therapy. Twenty-one patients with local recurrence were treated. Sites of recurrence were: tongue (9); nasopharynx (3); floor of mouth (2); soft palate (2); oropharynx (1); buccal mucosa (1); maxilla (1); larynx (1); and basal cell nevus (1). There were six complete responses and twelve partial responses (greater than 50% reduction). These responses are clinically significant, with some complete responses lasting over 1 year after a single course of therapy. Ten patients with cutaneous metastases from head and neck primary tumors were also treated. There were two complete responses and three partial responses. However, these patients rapidly developed new tumors in areas adjacent to those previously treated. Less than complete responses could be augmented by repeated applications of this technique. The success of this pilot study combined with the accessibility of head and neck primaries suggest that there should be a clinical trial of HPD-PRT in early mucosal cancer of the head and neck region.