Accuracy and precision of perfusion lung scintigraphy versus 133Xe-radiospirometry for preoperative pulmonary functional assessment of patients with lung cancer

Complication and lung function impairment prediction using perfusion and computed tomography air trapping (CLIPPCAIR): protocol for the development and validation of a novel multivariable model for the prediction of post-resection lung function

Background

Recent advancements in computed tomography (CT) scanning and post processing have provided new means of assessing factors affecting respiratory function. For lung cancer patients requiring resection, and especially those with respiratory comorbidities such as chronic obstructive pulmonary disease (COPD), the ability to predict post-operative lung function is a crucial step in the lung cancer operability assessment. The primary objective of the CLIPPCAIR study is to use novel CT data to develop and validate an algorithm for the prediction of lung function remaining after pneumectomy/lobectomy.

Methods

Two sequential cohorts of non-small cell lung cancer patients requiring a pre-resection CT scan will be recruited at the Montpellier University Hospital, France: a test population (N=60) on which predictive models will be developed, and a further model validation population (N=100). Enrolment will occur during routine pre-surgical consults and follow-up visits will occur 1 and 6 months after pneumectomy/lobectomy. The primary outcome to be predicted is forced expiratory volume in 1 second (FEV1) six months after lung resection. The baseline CT variables that will be used to develop the primary multivariable regression model are: expiratory to inspiratory ratios of mean lung density (MLD_e/i for the total lung and resected volume), the percentage of voxels attenuating at less than ‒950 HU (PVOX_‒950 for the total lung and resected volume) and the ratio of iodine concentrations for the resected volume over that of the total lung. The correlation between predicted and real values will be compared to (and is expected to improve upon) that of previously published methods. Secondary analyses will include the prediction of transfer factor for carbon monoxide (TLCO) and complications in a similar fashion. The option to explore further variables as predictors of post-resection lung function or complications is kept open.

Discussion

Current methods for estimating post-resection lung function are imperfect and can add assessments (such as scintigraphy) to the pre-surgical workup. By using CT imaging data in a novel fashion, the results of the CLIPPCAIR study may not only improve such estimates, it may also simplify patient pathways.

Trial registration

Clinicaltrials.gov (NCT03885765).

Comparison of predicted postoperative forced expiratory volume in the first second (FEV1) using lung perfusion scintigraphy with observed forced expiratory volume in the first second (FEV1) post lung resection

Lung perfusion scintigraphy is done as a part of preoperative evaluation in lung cancer patients for the prediction of postoperative forced expiratory volume in the first second (FEV1). This study was performed to see the accuracy of prediction of postoperative FEV1 by perfusion scintigraphy for patients undergoing lobectomy/pneumonectomy by comparing it with actual postoperative FEV1 obtained by spirometry 4-6 months after surgery. We retrospectively reviewed 50 surgically resected lung cancer patients who underwent preoperative spirometry, lung perfusion study, and postoperative spirometry. Pearson's correlation coefficient was used to evaluate the relationship between predicted postoperative FEV1 (PPO FEV1) by lung perfusion scintigraphy and postoperative actual FEV1 measured by spirometry. Agreement between the two methods was analyzed with Bland-Altman method. The correlation between the PPO FEV1 and actual postoperative FEV1 was statistically significant (r = 0.847, P = 0.000). The correlation was better for pneumonectomy compared to lobectomy (r = 0.930 [P = 0.000] vs. 0.792 [P = 0.000]). The agreement analysis showed a mean difference of -0.0558 with a standard deviation (SD) of 0.284. The limits of agreement vary over a wide range from --0.625 to 0.513 L (mean ± 2 SD) for the entire group. For pneumonectomy, the mean difference was -0.0121 and SD 0.169 with limits of agreement varying between -0.30 L and 0.30 L. For lobectomy, the mean difference was -0.0826 and SD 0.336 with limits of agreement varying between -0.755 L and 0.590 L. Postoperative FEV1 predicted using lung perfusion scintigraphy shows good correlation with actual postoperative FEV1 and shows reasonably good agreement in patients undergoing pneumonectomy. The limits of agreement appear to be clinically unacceptable in patients undergoing lobectomy, where single-photon emission computed tomography (SPECT) or SPECT/CT techniques may improve prediction.

Radioiodination, diagnostic nuclear imaging and bioevaluation of olmesartan as a tracer for cardiac imaging

The present work has been oriented to prepare radioiodinated olmesartan for a potential cardiac imaging. Olmesartan has been labeled using 125I or 131I with N-bromosuccinimide (NBS) as an oxidizing agent. Many factors like amount of N-bromosuccinimide, amount of substrate, pH, reaction temperature and reaction time, have been systematically studied to optimize high yield of [125I]iodoolmesartan. The biological distribution indicates the suitability of [125I]iodoolmesartan as a novel tracer to image heart.

Lung function in the late postoperative phase and influencing factors in patients undergoing pulmonary lobectomy

BACKGROUND

Lung function in the late postoperative phase after pulmonary lobectomy is insufficiently characterized. This study aimed to appraise lung function in the late postoperative phase according to vital capacity (VC) and forced expiratory volume in 1 second (FEV1) in patients who underwent pulmonary lobectomy.

METHODS

Pre- and postoperative VC and FEV1 were reviewed in 112 patients who underwent pulmonary lobectomy. Postoperative lung volume was assessed >1 year after surgery. Postoperative decreases in VC and FEV1 were compared with preoperative predicted values among patients who underwent resection of specific lobe. Determinants effecting a decrease in lung function were also investigated.

RESULTS

A mean postoperative decreased VC of 10.5%±1.8% was recorded in patients who underwent right upper lobectomy (RU), 7.2%±1.5% for right middle lobectomy (RM), 14.3%±2.3% for right lower lobectomy (RL), 16.6%±3.0% for left upper lobectomy (LU), and 14.7%±2.5% for left lower lobectomy (LL). Corresponding FEV1 values were 14.8%±1.8% for RU, 11.9%±4.0% for RM, 14.9%±2.3% for RL, 17.9%±2.9% for LU, and 15.1%±2.4% for LL. The actual decreasing rate of VC was overestimated in patients who underwent RU, RL, LU, and LL. In contrast, FEV1 was overestimated only in patients who underwent RL and LL. Patients with chronic obstructive pulmonary disease (COPD) exhibited significantly better preservation of FEV1.

CONCLUSIONS

Patients scheduled for RL and LL, or those with COPD, appeared to exhibit preserved lung function in the late postoperative phase after pulmonary lobectomy.

The role of dual-energy computed tomography in the assessment of pulmonary function

The assessment of pulmonary function, including ventilation and perfusion status, is important in addition to the evaluation of structural changes of the lung parenchyma in various pulmonary diseases. The dual-energy computed tomography (DECT) technique can provide the pulmonary functional information and high resolution anatomic information simultaneously. The application of DECT for the evaluation of pulmonary function has been investigated in various pulmonary diseases, such as pulmonary embolism, asthma and chronic obstructive lung disease and so on. In this review article, we will present principles and technical aspects of DECT, along with clinical applications for the assessment pulmonary function in various lung diseases.