Autofluorescence Bronchoscopy: A Novel Technique to Unleash the Buried Crab
Corresponding Author: Vidhya Priya S, Department of Respiratory Medicine, Shri Sathya Sai Medical College and Research Institute, Sri Balaji Vidyapeeth – Deemed to be University, Kancheepuram, Tamil Nadu, India, Phone: +91 9344215275, e-mail: firstname.lastname@example.org
How to cite this article: Priya SV, Vallabaneni V, Ragulan R, Varghese J, Sundarraj S. Autofluorescence Bronchoscopy: A Novel Technique to Unleash the Buried Crab. J Basic Clin Appl Health Sci 2022;5(2):58–59.
Source of support: Nil
Conflict of interest: None
Lung cancer is one of the most common cancers that causes death. Autofluorescence bronchoscopy is a recent technology which uses blue light to detect precancerous lesions that cannot be detected by conventional white light bronchoscopy. This is based on the principle that there is difference in emission of this light between premalignant and malignant tissue, that can be distinguished by a change in color emitted. Advantage of autofluorescence bronchoscopy is that it has excellent sensitivity in picking up abnormal tissues; therefore, early detection of cancers can be made, and appropriate treatment can be given, thereby increasing the survival. The major drawback of this procedure is that it lacks specificity.
Keywords: Autofluorescence bronchoscopy, Bronchoscopy, Lung cancer, Precancerous lesion.
Lung cancer is one of the most common cancers that causes death. Hence, early detection and treatment improve survival.1 Bronchoscopy is the most common modality used to detect lung cancers. The main disadvantage with the conventional bronchoscopy is that it uses white light, which makes it difficult to identify early cancerous lesions even for experienced bronchoscopists. Reports suggest that only 29% of carcinoma in situ lesions have been identified by white light bronchoscopy even when performed by experienced pulmonologist.2Autofluorescence bronchoscopy is a recent technology which uses blue light to detect precancerous lesions. This is based on the principle that normal tissue and cancerous tissue have difference in intensity.3
Autofluorescence bronchoscopy is a procedure wherein instead of white light like in traditional bronchoscopy, blue light through a specialized bronchoscope is used for illumination. The difference in emission of this light between premalignant and malignant tissue is distinguished by a change in color emitted. This is used to detect precancerous lesions, areas of dysplasia, small carcinomatous lesions, etc.4
Tissues emit fluorescence when exposed to light of specific wavelength. Autofluorescence bronchoscopy uses light source of specific wavelength that is used to illuminate bronchial tissues via bronchoscope. The image is captured by a camera and transmitted to system where the image is processed and produces an image to endobronchial tissues. The autofluorescence bronchoscopy systems are very sensitive to detect abnormal tissues.5
To screen high-risk patients.
Patients with sputum atypia and normal imaging.
To inspect for tumors in other sites in patients with known cancerous lesions.
To plan for treatment of early cancerous lesions.
To look for clearance following surgical resection of tumors.4
Contraindications to autofluorescence bronchoscopy are not different from routine bronchoscopy contraindications. They are severe hypoxia, recent myocardial infarction, bleeding diathesis, and hemodynamic abnormalities.6
A detailed history and physical examination should be done. Basic blood investigations and ECG should be done. Informed consent should be obtained from the patient and patient’s attender. Patient should be kept nil per oral for 6–8 hours prior to procedure. IV line secured and should be intact.6
Autofluorescence bronchoscopy is performed by a bronchoscopist and assisted by two respiratory therapists. It is performed under conscious sedation along with local anesthesia or general anesthesia in selective cases. First, the airway is inspected using conventional bronchoscope. Tissue specimens are not obtained at this point to avoid blurred images during the autofluorescence bronchoscopy. Then, the autofluorescence bronchoscopy is carried out like the normal bronchoscopy. Images of two different wavelengths (green and red) are captured and processed in system. The normal tissue appears green in color, and the abnormal tissue appears reddish in color. Postprocedure, the airway is inspected using conventional bronchoscope for any injury and any biopsies needed are done. Postprocedure, patient is started on orals after a period of observation. In the absence of any complications, they may be discharged. After uneventful recovery and in the absence of complications, the patient may be discharged on the same day.4,6
Complications are similar to conventional bronchoscopy. They are bleeding, hypoxia, pneumothorax, and cardiac abnormalities like arrhythmias, and rarely can cause death.6
A bronchoscopist should have performed at least 20 autofluorescence bronchoscopies under supervision before performing individually. Trained bronchoscopist should perform a minimum of 10 autofluorescence bronchoscopies per year to maintain competency.4
Advantage of autofluorescence bronchoscopy is that it has excellent sensitivity in picking up abnormal tissues.7
Disadvantage of autofluorescence bronchoscopy is that it has poor specificity.7
Vidhya Priya S https://orcid.org/0000-0002-9303-5063
2. Woolner LB, Fontana RS, Cortese DA, Sanderson DR, Bernatz PE, Payne WS, et al. Roentgenographically occult lung cancer: pathologic findings and frequency of multicentricity during a 10-year period. Mayo Clin Proc 1984;59(7):453–466. DOI: 10.1016/s0025-6196(12)60434-0.
3. Sutedja TG, Codrington H, Risse EK, Breuer RH, van Mourik JC, Golding RP, et al. Autofluorescence bronchoscopy improves staging of radiographically occult lung cancer and has an impact on therapeutic strategy. Chest 2001;120(4):1327–1332. DOI: 10.1378/chest.120.4.1327.
4. Crymes TP, Fish RG, Smith DE. Autofluorescence Bronchoscopy Definition Autofluorescence bronchoscopy is a bronchoscopic procedure in which a blue light rather than a white light is employed for illumination, and prema. CHEST 2003;123:1701. https://doi.org/10.1016/S0012-3692(15)33711-9.
6. Mahmoud N, Vashisht R, Sanghavi D, Kalanjeri S. Bronchoscopy. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448152/.
7. Edell E, Lam S, Pass H, Miller YE, Sutedja T, Kennedy T, et al. Detection and localization of intraepithelial neoplasia and invasive carcinoma using fluorescence-reflectance bronchoscopy: an international, multicenter clinical trial. J Thorac Oncol 2009;4(1):49–54. DOI: 10.1097/JTO.0b013e3181914506.
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