Superiority of single-photon emission computed tomography for predicting postoperative lung function after anatomical...

Accurate prediction of postoperative pulmonary function is crucial for surgical decision-making in patients undergoing anatomic lung resection for non-small cell lung cancer (NSCLC). Traditional assessment methods based on planar ventilation/perfusion (V/Q) scintigraphy or anatomical segment calculation (ASC) are limited by low spatial resolution and simplified assumptions of uniform segmental volume and contribution. The use of hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) has emerged as a modern alternative for three-dimensional functional assessment, but its comparative accuracy remains uncertain. Therefore, this study aimed to compare the accuracy of SPECT/CT with planar V/Q scintigraphy and ASC in predicting postoperative pulmonary function after anatomic lung resection.

We systematically searched PubMed, Embase, and the Cochrane Library through June 2025 for studies comparing SPECT/CT with conventional methods (planar V/Q scan or ASC) for predicting postoperative pulmonary function after anatomic lung resection. Eligible studies included adults with lung cancer reporting both predicted and observed postoperative forced expiratory volume in one second (FEV₁) and/or diffusing capacity for carbon monoxide (DLCO) values. Statistical analysis was performed using Bland-Altman plots, linear regression, and bar-plot comparison of absolute differences between predicted and observed values. The protocol was registered in PROSPERO (CRD420251103221).

Five studies comprising 424 patients met inclusion criteria. Across cohorts, mean age ranged from 66 to 68 years, and lobectomy represented the predominant type of surgical resection. SPECT/CT demonstrated the smallest bias and narrowest limits of agreement for both FEV₁ [mean difference (MD) =-4.5] and DLCO (MD =-2.2), outperforming ASC (MD =-4.2) and planar V/Q (MD =-12.9). Correlation between predicted and observed values was strongest with SPECT/CT (R²=0.89 for FEV₁; R²=0.91 for DLCO), intermediate with ASC, and weakest with V/Q. Absolute prediction errors were lowest with SPECT/CT, indicating superior agreement and precision. Overall evidence quality by Grading of Recommendation, Assessment, Development, and Evaluations (GRADE) was rated as moderate for SPECT/CT and low for conventional methods.

In patients with NSCLC undergoing anatomic lung resection, preoperative SPECT/CT provides the most accurate prediction of postoperative FEV₁ and DLCO values than planar V/Q scintigraphy or ASC. Our findings suggest that SPECT/CT should be considered the preferred modality for functional evaluation before lung resection, particularly in patients with borderline pulmonary reserve. Future multicenter prospective studies should validate standardized thresholds for surgical eligibility.