Lobar Quantification by Ventilation/Perfusion SPECT/CT in Patients with Severe Emphysema Undergoing Lung Volume Reduction with Endobronchial Valves

Respiration. 2019;98(3):230-238. doi: 10.1159/000500407. Epub 2019 Jun 5.

Abstract

Background: Endoscopic lung volume reduction (ELVR) therapy using one-way valves is used to treat chronic obstructive pulmonary disease patients with severe heterogeneous emphysema. A successful treatment results in atelectasis of the treated pulmonary lobe with subsequent reduction of ventilation (V) and perfusion (Q).

Objective: We evaluated the effects of ELVR on the targeted lobe using a new 3-dimensional ventilation and perfusion (V/Q) single-photon emission computed tomography (SPECT)/computed tomography (CT) analysis, which allows for simultaneous semi-automatic lobar pulmonary quantification of volume, ventilation and perfusion, on the first consecutive patients treated with ELVR at Rigshospitalet, Denmark. V/Q planar scintigraphy and V/Q SPECT/CT and lung function measurements were performed before and 6 months after intervention.

Results: We included 24 subjects (60 years, range 46-74 years; 37.5% men) with a baseline FEV1 of 25% predicted and RV of 257% predicted. V/Q SPECT/CT-assessed volume of the targeted lobe decreased by a mean of -395 mL and a relative mean of -26.8%, whilst ventilation and perfusion decreased by a relative mean of -37.1 and -25.7%. There was a significant increase in the same parameters of the non-targeted lobe(s) on the ipsilateral side. None of these changes were found in the analysis of planar V/Q imaging. The total lung volume decreased on average by -420 mL. Six months after ELVR, FEV1 had increased by 22%. Significant correlations were found between changes in FEV1 and changes in the volume of the treated lobe (SPECT/CT).

Conclusion: Semi-automatic SPECT/CT analysis can quantify volume, ventilation and perfusion changes in pulmonary lobes and may be used in the assessment of patient eligibility for ELVR, identifying target lobes, and evaluation of the regional effects of treatment.

Keywords: Bronchoscopy; COPD; Computed tomography; Lung volume reduction; Perfusion; Planar scintigraphy; SPECT; Valve; Ventilation.

MeSH terms

  • Aged
  • Bronchoscopy*
  • Female
  • Forced Expiratory Volume
  • Functional Residual Capacity
  • Humans
  • Image Processing, Computer-Assisted
  • Lung Volume Measurements / methods
  • Male
  • Middle Aged
  • Pneumonectomy*
  • Prospective Studies
  • Pulmonary Diffusing Capacity
  • Pulmonary Emphysema / diagnostic imaging*
  • Pulmonary Emphysema / surgery
  • Residual Volume
  • Severity of Illness Index
  • Single Photon Emission Computed Tomography Computed Tomography / methods*
  • Surgical Instruments
  • Total Lung Capacity
  • Treatment Outcome
  • Ventilation-Perfusion Scan / methods*