The Role of Narrow Band Imaging (NBI) Bronchoscopy in Detecting Bronchial Squamous Dysplasia in Lung Cancer

1. Study Design: This is an observational diagnostic study. The research was conducted at the Central Surgical Installation (CSI) of Persahabatan Hospital, where bronchoscopy procedures, bronchial biopsy collection, and specimen handling took place. The histopathological examinations were carried out in the Department of Anatomical Pathology, Faculty of Medicine, Universitas Indonesia, Cipto Mangunkusumo National General Hospital. The patient recruitment time ranges from March to December 2023.
2. Population: The target population consists of all lung tumor patients. The accessible population consisted of lung tumor patients who underwent bronchoscopy procedures at Persahabatan Hospital from March to December 2023.
3. The study participants: The study participants comprised individuals from the accessible population who met the research subject acceptance criteria and provided informed consent. The consecutive sampling method was employed.
4. Study participants size calculation: The study participants size was calculated using the diagnostic research sample size formula. The minimum study participants size required was 110 subjects.
5. Inclusion criteria:

• Patient aged > 18 years undergoing bronchoscopy for diagnostic evaluation of lung tumors
• Recent radiological examinations, including both chest X-ray and chest CT scans, within the last month, revealed a central lesion of lung cancer

6. Exclusion criteria:

• Refusal to provide informed consent
• Contraindications to bronchoscopy

7. Study participants selection: Screening was conducted on all lung tumor patients scheduled for bronchoscopy procedures, and the study participants selection was carried out in accordance with the inclusion and exclusion criteria
8. Sampling Technique:

The preparation and execution of bronchoscopy and bronchial biopsy were performed in accordance with the standard operating procedures (SOP) at Persahabatan Hospital. The bronchoscopy and bronchial biopsy procedures were conducted by a single operator, the principal investigator. The bronchoscopy procedure uses general anesthesia. The flexible fiberoptic bronchoscopy was performed using an Olympus EVIS EXERA III with a Xenon light source, model CLV-190, and BF-1TQ170 series scope. The Boston Scientific Radial JawTM 4 disposable lung biopsy forceps were employed. Bronchoscopy was initially conducted under the white light, followed by narrow-spectrum light. The NBI assessment was performed in two areas, consisting of area 1 (trachea and carina) and area 2 (right main bronchus, right upper lobe orifice, truncus intermedius, right lower lobe orifice, left main bronchus, left upper lobe orifice, and left lower lobe orifice). Biopsies were taken from both areas based on the NBI bronchoscopy findings. Tissue from each area was placed in a separate 10% formalin solution. Tissue processing involved paraffin embedding and Hematoxylin-Eosin staining. Tissue processing was performed using a Tissue Processor machine. Following tissue processing, paraffin blocks were created and sectioned. Hematoxylin-Eosin staining was then performed. Diagnosis of squamous bronchial dysplasia (pre-cancer lesion) was made by a specialist in Anatomical Pathology. 9. Data analysis: The research data were recorded on research forms and subsequently entered into SPSS 26 software. the bivariate analysis was conducted between each vascular pattern based on NBI bronchoscopy and the histopathological result. The descriptive data will be presented by the text and tables consist of the basic characteristics of the study participants and research variables. The multivariate analysis was performed on all vascular patterns based on NBI bronchoscopy and histopathological results. Furthermore, a pre-cancer prediction score was generated. An analysis of the AUC (area under the curve) of the squamous dysplasia prediction model form NBI bronchoscopy findings was conducted with a significance level set at p < 0.0.5