PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 30 days since prior chemotherapy (6 weeks since nitrosoureas) Endocrine therapy: Concurrent steroid therapy allowed Radiotherapy: At least 30 days since prior radiotherapy to the head and neck Surgery: At least 30 days since prior surgery and recovered Other: At least 30 days since prior light activated therapy or medication (e.g.,PUVA or Accutane) No prior photodynamic therapy At least 30 days since prior experimental drugs