OBJECTIVE: To demonstrate the possibilities, advantages and limitations of virtual bronchoscopy using data sets from positron emission tomography (PET) and computed tomography (CT). MATERIALS AND METHODS: Eight consecutive patients with non-small cell lung cancer (NSCLC) underwent PET/CT. PET was performed with a glucose analog, 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (18F-FDG), using a state-of-the-art full-ring Pico-3D PET scanner. CT was performed with a venous-dominant contrast-enhanced phase using a 16-slice CT scanner.

The performance of the Lung Imaging Fluorescence Endoscope (LIFE) system was compared with conventional bronchoscopy in 158 patients: 68 patients with invasive cancer, 42 patients with abnormal sputum cytology findings (12 early cancer and 26 dysplasia), 17 cases with resected lung cancer and 31 smokers with symptoms. The respective results of conventional bronchoscopy and LIFE for detection of dysplasia were; sensitivity 52% and 90% (biopsy basis), 62% and 92% (patient basis).

A new autofluorescence (AF) system for bronchoscopy that operates as compact as a conventional white light bronchoscopy system is described. The system is also capable of white light illumination and excitation of aminolevulinic acid (ALA) induced fluorescence. Changing between white light and (auto-) fluorescence mode is easy and always possible. Broad band excitation with blue light (AF: 380-460 nm; ALA 380-440 nm) delivers high intensity illumination at the distal end of the bronchoscope (AF typically 50 mW).

At the moment only early detection of lung cancer offers a good prognosis for the patients. Conventional white light endoscopy is mostly insufficient for early diagnosis. Therefore we developed a system of fluorescence diagnosis using 5-aminolaevulinic acid (ALA) exogeneously applied. As precursor of the heme synthesis it is metabolized to protoporphyrin IX - a red fluorescent substance. Therefore protoporphyrin IX accumulates in tumorous and premalignant tissue, and can be directly visualized by fluorescence bronchoscopy.

A fluorescence imaging system (Xillix LIFE - Lung Fluorescence Endoscopy system) using fluorescence for the accurate diagnosis and early detection of lesions through an endosocope has been developed. This system has applied an optical diagnostic technology to functionally diagnose lesions which have been difficult to morphologically recognize or are occult with conventional endoscope. The benefit of this system in the diagnosis of lung cancer has already been confirmed in the US and Japan, and feasibility of the system in the gastric intestinal field has also been evaluated.

Early diagnosis is the way to improve the rate of lung cancer survival, but is almost impossible today due to the lack of molecular probes that recognize lung cancer cells sensitively and selectively. We developed a new aptamer approach for the recognition of specific small-cell lung cancer (SCLC) cell-surface molecular markers. Our approach relies on cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX) to evolve aptamers for whole live cells that express a variety of surface markers representing molecular differences among cancer cells.