179 - Results of a Prospective Trial to Evaluate Novel Lung Function Imaging for Lung Cancer Surgery

L. J. Wilson¹, R. Castillo², E. Castillo³, B. L. Jones⁴, M. Miften⁴, L. Olsen⁵, V. Aragam¹, R. A. Meguid⁶, C. Erickson⁷, A. Young⁸, M. Blum⁹, T. Grenda¹, J. Barta¹, B. E. Leiby¹⁰, T. V. Waxweiler¹¹, B. D. Kavanagh⁴, J. D. Mitchell¹², and Y. Vinogradskiy¹³; ¹Thomas Jefferson University, Philadelphia, PA, ²Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA, ³Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, ⁴Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO, ⁵Memorial Hospital, Colorado Springs, CO, ⁶Department of Surgery, University of Colorado School of Medicine, Aurora, CO, ⁷UCHealth Thoracic Surgery, Colorado Springs, CO, ⁸University of Colorado Anschutz, Aurora, CO, ⁹University of Colorado Health, Colorado Springs, CO, ¹⁰Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, PA, ¹¹Department of Radiation Oncology, University of Colorado School of Medicine, Colorado Springs, CO, ¹²University of Colorado, Aurora, CO, ¹³Department of Radiation Oncology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA

Purpose/Objective(s): Surgery is the primary form of definitive treatment for early-stage lung cancer. Patients with poor lung function before surgery are at high risk of pulmonary complications after resection. Surgeons evaluate patient fitness for surgery using pulmonary function tests (PFTs) and calculate the predicted postoperative PFT (ppoPFT) values by estimating the volume of lung tissue to be resected. Conventional ppoPFT calculations assume a homogeneous lung function, which can be inaccurate. 4DCT-ventilation is a novel lung function imaging modality developed in radiation oncology that uses 4DCT data to calculate ventilation maps. The purpose of this study was to report the first pilot clinical trial to prospectively investigate the suitability of 4DCT-ventilation for lung cancer surgical evaluation. Materials/

Methods: The trial enrolled patients with lung cancer who were being evaluated for surgical resection. Eligible patients were being considered for pneumonectomy, lobectomy, or segmentectomy. Each patient underwent PFTs and 4DCT imaging prior to surgery and 3 months after surgery. Previously validated image processing techniques generated 4DCT-ventilation images using the presurgical 4DCT data. We calculated 4DCT-ventilation-based ppoPFTs by scaling preoperative PFTs by the 4DCT-ventilation-based lung function in the delineated surgical volume. We compared ppoPFTs to true postoperative PFTs using the concordance correlation coefficient (CCC) and root mean squared (RMS) error for the 3 most common PFT measures: Forced Expiratory Volume in 1 s (FEV1), Forced Vital Capacity (FVC), and Diffusing Capacity of the Lungs for Carbon Monoxide (DLCO). The primary endpoint was CCC between 4DCT-ventilation-based ppoPFTs and true postoperative PFTs, with a hypothesized correlation = 85%.
Results: From 05/2018 to 08/2021, 65 patients consented to the study and 37 completed presurgical 4DCT and pre- and post-surgical PFTs. 26 (70%) patients underwent lobectomy and 11 (30%) underwent segmentectomy. The 4DCT-ventilation-based CCCs for predicting true postoperative PFTs were 90%, 87%, and 89% for FEV1, FVC, and DLCO, respectively. The RMS errors in 4DCT-ventilation-based ppoPFTs were 13.5%, 14.9%, and 14.4% for FEV1, FVC, and DLCO, respectively.
Conclusion: This was the first pilot study to prospectively evaluate the accuracy of 4DCT-ventilation imaging for predicting PFT-based lung function following lung cancer surgery. The study met the primary CCC criteria for the 3 most common PFT measures with variations observed in individual patients. Future work will evaluate individual patient differences, compare 4DCT-ventilation with conventional ppoPFT calculations, and develop more sophisticated algorithms for postoperative lung function prediction. 4DCT-ventilation methods developed in radiation oncology can be innovatively applied to improve the ability of surgeons to quantitatively evaluate patient appropriateness and safety for lung cancer resection.