1. Sensitivity and Diagnostic Accuracy of Different Sampling Modalities with
Electromagnetic Navigational Bronchoscopy & Effect of Radial EBUS on Yield
Deepankar Sharma, MD and Christina Bellinger, MD
Department of Pulmonary and Critical Care Medicine, Wake Forest School of Medicine
Introduction
Objectives
Results
Discussion
Lung cancer continues to be the leading cause of deaths in both men and women. With national lung cancer screening trial and recent development in screening guidelines, more and more peripheral lung nodules are being discovered.
Lung nodules represent a challenge as obtaining tissue biopsy from these lesions require safe and accurate modality with minimal peri-operative morbidity.
Electromagnetic navigational bronchoscopy (ENB) is a recent technology that allows a relatively safer method to biopsy lung nodules and has been recommended by ACCP for diagnosis of lung cancer if the lung lesions are difficult to reach with conventional bronchoscopes.
ENB is a vital tool in diagnosing malignant and benign peripheral lung lesions, providing a safer alternative than trans-thoracic needle aspirations.
At Wake Forest, ENB was implemented in 2011 using Medtronic’s “Super Dimensional” system. It is performed by few physicians at Wake Forest who have had training and experience in performing this and other advanced bronchoscopic procedures.
As this is a relatively new technology, the best sampling modality has yet to be determined.
We present one such study aimed to evaluate the sensitivity of different sampling modalities independently and in combination. We also evaluated the difference in yield and sensitivity with the addition of radial probe EBUS.
To assess the overall yield and accuracy of ENB in diagnosing malignancy and infection as the underlying cause of lung nodules/mass.
To evaluate the diagnostic accuracy and sensitivity of different sampling modalities (needle aspiration, brush biopsy, trans-bronchial forceps biopsies) independently and in combination.
To evaluate the difference in diagnostic accuracy and sensitivity with the addition of radial probe EBUS to augment ENB.
To understand the change in procedural accuracy with experience at a single institution.
To evaluate effect of location of the lesion on the sensitivity and accuracy of ENB.
Many studies reported overall sensitivity and accuracy but none to our knowledge evaluated the sensitivities and accuracy of different sampling instruments.
At our institution, most common indication for ENB is lung nodule (52%) followed by lung mass (42%).
Out of all the malignancies, adenocarcinoma was the most common (47%) followed by squamous cell cancer (25%).
Rapid on-site cytology was used in 50% of cases and have a sensitivity of 81% with 100% specificity.
Overall complication rate was 8.9% with pneumothorax being the most common complication (4.7%) followed by post operative hypoxia (2%) and 1 (<1%) case each of pneumonia, bleeding and bronchospasm.
Until 2016, our program offered a third year track for 1 year of dedicated training in field of interventional pulmonology. Presence of IP fellow during the ENB procedure improved its sensitivity from 53% to 61% and diagnostic accuracy from 65% to 73%.
Total Patients: 148
Total no. of lesions: 164
Sensitivity & accuracy by location of the lesion
Lost follow up: 4
Follow up pending: 2
Failed to register: 2
Lesion not reached: 5
N = 65
Sensitivity: 65% Accuracy: 74%
Total Patients included: 135
Total no. of lesions included: 145
Malignant: 60 (42%)
Infection: 8 (6%)
Benign: 35 (24%)
N = 22
Sensitivity: 81% Accuracy: 86%
Baseline characteristics
Lesion size
24.7 +/ mm
Bronchus sign
137 (95%)
Procedure duration
71 +/- 28 mins
Concurrent linear EBUS
92 (61%)
N = 58
Sensitivity: 43% Accuracy: 63%
Methods
Retrospective study chart review of all the patients that had ENB performed at our tertiary care, university hospital since its implementation in 2011.
The study was approved by IRB.
We reviewed the lesion size, location, airway-lesion relationship, cytology and pathology results reported per sampling modality, results of molecular marker tests (EGFR, ALK and ROS1) and if the Radial EBUS was used in conjunction with ENB or not.
Patients with no evidence of malignancy on ENB guided biopsy were followed up with imaging or subsequent biopsies using other modalities to determine true benign nature of their lesion.
Conclusion
Although our overall sensitivity was low, there has been a significant improvement with experience. Our sensitivities using various sampling modalities demonstrates that a combined approach may be most advantageous and involvement of formally trained physicians and use of radial probe EBUS may improve yield.