diaddddddd122223d Diagnosis of esophagial cancer (Artesh medical university) Dr Saidi
When think about it? dysphagia (Transient "sticking ) weight loss retrosternal discomfort or a burning sensation screening for or surveillance of Barrett's esophagus Regurgitation of saliva or food uncontaminated by gastric secretions iron deficiency anemia intractable coughing or frequent pneumonias
How to evaluate the patient? Barrium swallow : may suggest the presence of esophageal cancer Endoscopy : While the endoscopic visualization of a large mucosal mass is nearly pathognomonic of esophageal cancer, biopsy must be performed to confirm the diagnosis : First biopsy — 93 percent Four biopsies — 95 percent Seven biopsies — 98 percent
Chromoendoscopy Lugol's solution Toluidine blue Screening for early squamous esophageal cancers in alcohol and tobacco abusers [13] and patients with head and neck cancers13 Staining metaplasia in the esophagus (Barrett's esophagus)
Magnification endoscopy Magnification endoscopes include an adjustable focusing mechanism that permits standard endoscopic views and the ability to enlarge the image from 1.5X to 150X Resolution is related to pixel density. Conventional endoscopes have pixel densities in the range of 100,000 to 200,000. By contrast, the newest magnification endoscopes have pixel densities as high as 850,000
Fluorescence spectroscopy Fluorescence diagnosis can be achieved by measuring either fluorescence generated by endogenous molecules ( autofluorescence ) or tissue fluorescence following administrationof an exogenous agent ( drug-enhanced fluorescence ).
FLUORESCENCE IMAGING In parallel with point spectroscopy, real-time fluorescence imaging prototypes have been developed, providing a field of view similar to that of a conventional endoscope.The LIFE (light-induced fluorescence endoscopy) system uses a blue light source for tissue excitation and two intensified charged coupled device (CCD) cameras for the detection of green (490–560 nm) and red (O630 nm) fluorescence.
GRAPOPTICAL COHERENCE TOMOGRAPHY Optical coherence tomography (OCT) is the optical analogue of high frequency B mode ultrasonography. OCT images are acquired in near realtimeand with a resolution that is 10-fold higher than that of endoscopicultrasound (EUS), thereby allowing identification of microscopic features such as villi, glands, and crypts.
Clinical application In its current state, OCT will likely localize areas displaying architectural distortion for biopsy, but may play only a limited role in the detection and staging of dysplastic lesions. OCT may be useful, however, for determining lesion extension into the submucosa and aid in the selection of patients suitable for endoscopic mucosal resection. Assessment of the stomach by OCT is more challenging and of limited value, since the thick and highly scattering gastric mucosa restricts imaging depth and contrast.
Summary Conventional white light endoscopy with biopsy remains the gold standard for the identification of pre-malignant and early malignant changes in the upper GI tract these modalities are likely to be used by the endoscopist as guiding tools for targeted biopsies, and to more accurately assess lesion margins and adequacy of endoscopic treatment.