[Photodynamic therapy of roentgenographically occult lung cancer].

Between December 1983 and August 1990 25 patients (a total of 29 carcinomas) with roentgenographically occult lung cancer were treated by PDT at National Kinki Central Hospital for Chest Diseases. A complete remission (CR) occurred in 21 carcinomas (72%). Of 19 carcinomas with tumor length of 1 cm or less, 17 ones (89.5%) achieved a CR. Of 21 carcinomas with visible tumor of the peripheral area, 17 ones (85.7%) achieved a CR. Five carcinomas relapsed from 7 to 18 months after PDT. The length of tumor and the visibility of peripheral area of tumor are important factors for CR and relapse. Fourteen patients (56%) had double, triple or quadruple cancers. Until now, 10 patients died. The main causes of death were metachronous secondary cancers and respiratory or heart failure. PDT have a potential to become an alternative to surgical resection as the primary treatment for early stage roentgenographically occult lung cancer.