Use of Ventilation-Perfusion Single-Photon Emission Computed Tomography to Select the Target Lobe for Endobronchial Valve Lung Volume Reduction

Abstract

<b><i>Background:</i></b> Quantitative planar ventilation-perfusion (VQ) has a complementary role in target lobe selection for endobronchial valve lung volume reduction (EBV-LVR), especially in homogenous disease. We investigated a novel method of lung lobar quantitation using VQ single-photon emission computed tomography (SPECT) with computed tomography (CT) to generate a parameter called the ventilation-perfusion differential index (VQDI). <b><i>Aim:</i></b> The aim of this study was to validate VQDI as a parameter for target lobe selection in EBV-LVR against the gold standard test of quantitative computed tomography (qCT). <b><i>Methods:</i></b> This study was a prospective, multi-centre, single-blinded, observational study of EBV-LVR patients. Baseline and 3-month post intervention VQ SPECT and qCT were performed. The target lobe was chosen using qCT and planar VQ report (CT<sub>TL</sub>) whilst blinded to VQDI. Post EBV-LVR, our nuclear physician, blinded to CT<sub>TL</sub>, selected a target lobe using deidentified VQDI (VQDI<sub>TL</sub>). Inter-rater agreement between CT<sub>TL</sub> and VQDI<sub>TL</sub> was calculated by Kappa statistic. Treatment outcomes were analysed with a linear mixed-effects model. <b><i>Results:</i></b> There was a high concordance between CT<sub>TL</sub> and VQDI<sub>TL</sub> in 16 patients (89%, Kappa statistic = 0.85). Post EBV-LVR, our subjects showed significant changes in FEV1 (mean difference [MD] +150 mL, <i>p</i> < 0.001), target lobe volume reduction (MD −973 mL, <i>p</i> < 0.001), residual volume (MD −800 mL, <i>p</i> < 0.001), and St. George’s Respiratory Questionnaire score (MD −11, <i>p</i> = 0.001). Improvements in 6-minute walk distances did not reach statistical significance. <b><i>Conclusion:</i></b> In this study of treatment responders, EBV-LVR target lobe selection using VQDI concurs with qCT and thus supports its value for this purpose. It complements qCT and may potentially be of synergistic value especially in homogenous emphysema.

Lobar quantification of pulmonary perfusion prior to minimally invasive lung reduction improves prediction of postprocedure outcomes: A pilot study

“…This study evaluated the lobar perfusion algorithm relative to zonal perfusion and found that the former was not inferior to the standard of care imaging conducted by the zonal perfusion as previously demonstrated in other studies (Gao et al, 2020;Provost et al, 2017;Singh et al, 2020;Tee et al, 2021). It is important to note that zonal perfusion still has clinical merit as apical lung quantification is better characterized using the zonal perfusion algorithm of the upper lobes.…”

“…Traditionally quantitative lung perfusion was performed utilizing planar imaging with molecular imaging processing software dividing the lungs into upper, middle and lower zones and analyzing counts obtained from each zone as opposed to anatomical lobar anatomy. With the increased use of SPECT/CT and development of CT‐based fissure‐identifying artificial intelligence algorithms, quantification perfusion studies can now be performed with lobar analysis with small studies showing enhanced quantification of the perfusion in a 5‐lobar analysis (Gao et al, 2020; Provost et al, 2017; Singh et al, 2020; Tee et al, 2021).…”

Quantitative lobar Tc99m-MAA SPECT/CT of the lung in pre-and post-procedural guidance for bronchoscopic lung volume reduction

“…We set out in this study to define the role of nuclear medicine, particularly quantitative lobar SPECT/CT, in BLVR therapy. Prior trials have shown the utility of SPECT/CT when there are multiple candidate target lobes, particularly in cases of homogenous or mild heterogenous emphysema [16]. Therefore, the objective is to define the role of SPECT/CT in cases of homogenously affected emphysematous lungs in which high-resolution CT (HRCT) could not identify a single suitable target lobe.…”

“…Therefore, the objective is to define the role of SPECT/CT in cases of homogenously affected emphysematous lungs in which high-resolution CT (HRCT) could not identify a single suitable target lobe. Prior studies such as Tee et al [16] and Kristiansen et al [17] have investigated SPECT/CT's role in BLVR planning with preliminary results showing its utility in a small sample size [17]. Tee et al [16] investigated a mixed distribution of homogenous and heterogenous emphysema.…”

Endoscopic lung volume reduction with endobronchial valves for severe chronic obstructive pulmonary disease: a coming of age in Australia

“…9 While ELVR with EBV has been performed in Australia since 2007, local evidence has been, until recently, focussed on mechanisms of action and assessment criteria. [10][11][12] However, there have now been two recent studies published with local data utilising accepted international guidelines for selection, which allows us to examine the local experience. The first by Sidhu et al 13 was a retrospective consecutive review of 39 patients undergoing ELVR with EBV at two Victorian centres.…”