Usefulness of 5-aminolevulinic acid-photodynamic for diagnosing lung cancer

Yoon, Sung Ho; Lee, Seung Il; Kwon, Yong Eun

Abstract

BACKGROUNDS/AIMS
Photodynamic diagnosis (PDD) is a modern method for fluorescence imaging of a bronchogenic malignancy. Adverse effects and high costs, partly related to the general application of photosensitizers, are important limitations of the method. However, local application of a photosensitizer could help minimize these problems. 5-Aminolevulinic acid (ALA)-induced fluorescence promotes tumor selective accumulation of protoporphyrin, so tumors can be distinguished from healthy tissue. We compared white light bronchoscopy (WLB) with PDD for the early detection and exact staging of lung cancer.
METHODS
We examined 56 stage I and II lung cancer patients (age 65 years; range, 44.83) by photodynamic bronchoscopy (D-Light/AFsystem; Karl Storz GmBH, Tuttlingen, Germany) who had symptoms of cough, sputum, and hemoptysis with atypical cells in sputum cytology. Biopsies were taken from suspected lung cancer by both methods, and 181 lesions were analyzed.
RESULTS
The diagnostic accuracy of WLB, using histopathologic results as the standard, was 48.6%, whereas the accuracy using ALA-PDD was 73.5%. The sensitivity of WLB for detecting dysplasia or cancer was 57.1%, and the specificity was 85.6%. When the results from ALA-PDD were considered, these values were 90.5% and 79.1%, respectively. Of 2 patients with carcinoma in situ, only ALA-PDD revealed the lesions. Three patients with initial stage I or II became stage IIIB or IV after ALA-PDD.
CONCLUSIONS
Early detection and exact staging of lung cancer can be facilitated using a combination of ALA-PDD and WLB.