Purpose The study aimed to evaluate whether the relative height (RH) of the entry point (EP) during CT-guided lung biopsies, adjusted for patient positioning, can predict the risk of pneumothorax during the intervention, leveraging the gravitational effects on pleural pressure.Materials And Methods We retrospectively analyzed 128 percutaneous CT-guided lung biopsies performed at a single center between January 2018 and December 2023. Patients were grouped based on pneumothorax occurrence. Various measurement methods indirectly assessed the influence of gravitational force on pleural pressure, focusing on the RH at the EP with prone positioning adjustments (PP). Other confounding factors like patient demographics, lesion characteristics, pre-puncture fluid administration and other procedural details were assessed. Test performance metrics were compared using Chi-Square, Fisher's exact, and Mann-Whitney U tests. Univariate and binomial logistic regression assessed the influence of different parameters on pneumothorax occurrence.Results All measurements of lower RH at EP and pre-puncture fluid administration were significantly associated with a reduced incidence of peri-interventional pneumothorax (p < 0.01). The RH at EP adjusted for the prone position demonstrated the best predictive performance (AUC = 0.844). After adjusting for various confounding factors, both lower RH at EP adjusted for the prone position (OR 110.114, p < 0.001) and pleural fluid administration (OR 0.011, p = 0.011) remained independently associated with a lower risk of pneumothorax.Conclusion Strategic use of gravity by selecting the lowest possible entry point, ideally positioning the patient laterally, combined with pre-puncture pleural fluid administration, could be the key to reducing pneumothorax in CT-guided lung biopsies.
