Photodynamic therapy of endobronchial malignancies

Abstract

Forty-nine tumor sites in 31 consecutive patients with tracheobronchial malignant neoplasms were treated with photodynamic therapy (PDT). After sensitization with the intravenous hematoporphyrin derivative (HpD) or its more purified form of dihematoporphyrin ether (DHE), 630 nm of light from a tunable sensitizer argon light system was delivered to the tumor site through the biopsy channel of a flexible bronchoscope. All patients had received, refused, or were ineligible for conventional surgery, ionizing radiation therapy, or chemotherapy. Before or at 1 month after each treatment, tumor response was evaluated according to the following categories: (1) complete response (CR) (no visible abnormality, and negative biopsy specimen and cytology); (2) partial response (PR) (degree of obstruction or size of tumor reduced more than 50%); (3) some response (SR) (degree of obstruction or size of tumor reduced 20% to 50%); and (4) progression (PROG) (degree of obstruction or size of tumor reduced by less than 20%). Results were as follows: (1) 37% of the tumors treated achieved CR; (2) 55% achieved PR; (3) 4% achieved SR; and (4) 4% were categorized as PROG. Complete follow-up was achieved in all patients. Clinical effect was evaluated 1 month after treatment by comparing the Karnofsky performance status (KPS), dyspnea level, oxygen requirement, and presence of symptoms. Sixty-eight percent had clinical improvement in at least one variable and 48% in two or more variables. The results of this study suggest that PDT can play a useful role in the treatment of endobronchial malignancies.