Predicting Lung Volume Reduction after Endobronchial Valve Therapy Is Maximized Using a Combination of Diagnostic Tools

Abstract

Background: Bronchoscopic lung volume reduction using one-way endobronchial valves (EBVs) has been proven to be effective in patients with severe emphysema. However, the selection of patients without collateral ventilation prior to treatment is critical for procedural success. Collateral ventilation can be assessed directly with the Chartis system or indirectly using computed tomography (CT) fissure analysis. Objectives: We retrospectively evaluated the diagnostic value of a combination of the quantitative CT interlobar fissure completeness score (FCS) and Chartis in predicting responders to EBV therapy. Methods: CT data from four prospective studies were pooled and analyzed using semiautomated software to quantify the completeness of interlobar fissures. These FCSs were compared to a reference standard of achieving ≥350 ml of target lobe volume reduction after EBV treatment. Using a receiver operating characteristic curve, optimal thresholds predictive of complete fissures (responders) and incomplete fissures (non-responders) were determined. A subgroup of patients with partially complete fissures was identified, where software had lower accuracy. The complementary value of Chartis was investigated in this group. Results: A fissure was defined as complete (FCS >95%), incomplete (FCS <80%), or partially complete (80% < FCS < 95%). The positive predictive value (PPV) of complete fissures is 88.1%, and the negative predictive value (NPV) is 92.9%, with an overall accuracy of 89.2%. Chartis was utilized in patients with partially complete fissures, with a PPV of 82.3%, an NPV of 84.6%, and an accuracy of 83.3%. Conclusion: Combining diagnostic tools could reduce the burden on patients and the healthcare system while providing clinicians with a better means for patient selection for EBV therapy.

Endobronchial Valves for Endoscopic Lung Volume Reduction: Best Practice Recommendations from Expert Panel on Endoscopic Lung Volume Reduction

“…Quantitative CT analysis has shown early promise, with predictive capabilities in the same range as Chartis in small data sets [7] . More recent data [8] support the use of quantitative CT measurements to screen in patients for further analysis and/or treatment with fissure completeness ≥ 80%. Patients with fissure integrity <80% are not considered for EBV treatment.…”

Endoscopic Lung Volume Reduction: An Expert Panel Recommendation – Update 2019

“…Semi-automated analysis evaluating the integrity of the fissure on a thin-slice CT scan has been developed by several companies. In a recently published paper by Koster et al [18], CT data from four prospective studies were pooled and analyzed using semi-automated software to quantify the completeness of interlobar fissures. These fissure completeness scores (FCSs) were compared to a reference standard of achieving ≥350 mL of target lobe volume reduction after EBV treatment.…”

Role of Quantitative Computed Tomographic Scan Analysis in Lung Volume Reduction for Emphysema

“…In 2016, Koster et al [46] combined the quantitative CT interlobar fissure completeness score and the Chartis System® in the assessment of patients receiving endobronchial valves. This resulted in a high diagnostic pre-procedural assessment for predicting patients with LVR ≥350 mL [46].…”

“…This resulted in a high diagnostic pre-procedural assessment for predicting patients with LVR ≥350 mL [46]. Collateral ventilation measurement is therefore recommended if the quantitative CT revealed fissure completeness between 80 and 95% to ensure the absence of collateral ventilation [47].…”