AIRWAY IMAGING APPROACHES

Bronchoscopic Optical Techniques Although invasive,
fiberoptic bronchoscopy has been considered in certain
high-risk lung cancer screening contexts. Autofluorescence
bronchoscopy (AFB), based on altered refractile properties of
multilayered hyperplastic or dysplastic epithelium, has proven
superior to conventional white-light bronchoscopy (WLB) in
detecting moderate-to-severe dysplasia, and carcinoma in situ
with 56% to 82% sensitivity (AFB), versus 9% to 58% sensitivity
(WLB). 7,8 AFB is not universally available. Because there
are several localized responses to detection of premalignancy and
overt but confined bronchial malignancies (Nd:YAG laser therapy,
photodynamic therapy [PDT], electrocautery, cryotherapy,
and brachytherapy), some have advocated routine bronchoscopic
screening of individuals determined as high risk by other means
(e.g., high-grade sputum atypia, chronic obstructive pulmonary
disease [COPD], asbestos exposure). 9,10 Specificity of AFB has
been a question. Advancement of WLB techniques, including
light-scattering technologies and videobronchoscopy, is imminent.
4,11–14 High-density radiographic CT image reconstruction
has allowed for the development of virtual bronchoscopy ,
a technique that is completely noninvasive, although radiation
dose is not trivial, and radiologist/computer evaluation strategies
still evolving 15 (see Chapters 19 and 28).