Associations of Pleural Puncture Angle and Other Factors With Major Adverse Events After Thermal Lung Tumor Ablation: A Two-Center Study.

. Applicator insertion parallel to the bronchovascular bundle has been recommended for percutaneous ablation of central lung tumors. However, the relationship between the applicator insertion angle and adverse events remains understudied. . The purpose of this study was to examine associations of the pleural puncture angle and other factors with major adverse events after percutaneous ablation of lung tumors. . This retrospective study included consecutive patients who underwent percutaneous cryoablation or microwave ablation (MWA) of lung tumors at two academic medical centers between February 1, 2008, and April 30, 2023. A reader measured the pleural puncture angle on intraprocedural CT images. A second reader independently performed measurements in a subset to assess interreader agreement. Sessions were classified as central if at least one targeted tumor was located more than 4 cm from the costal pleura and as noncentral otherwise. The relationship between major adverse events and the pleural puncture angle was evaluated by separate multivariable logistic regression models for central and noncentral sessions; models also included modality (cryoablation vs MWA), number of pleural punctures (< 3 vs ≥ 3), applicator path through lung parenchyma, and maximum applicator gauge. . The analysis included 260 patients (152 women, 108 men; median age, 65 years) who underwent 416 sessions (299 cryoablation procedures, 117 MWA procedures; median pleural puncture angle, 57°) targeting 638 tumors. Interreader agreement for pleural puncture angle in 100 randomly selected cases was excellent (intraclass correlation coefficient = 0.94). A total of 86 (21%) sessions were classified as central and 330 (79%) as non - central. Major adverse events occurred after 37 (9%) sessions. In multivariable analyses, for central sessions, major adverse events were independently associated only with pleural puncture angle (OR per 1° = 0.94; = .01); in noncentral sessions, major adverse events were independently associated with MWA (OR = 2.98; = .03) and three or more pleural punctures (OR = 3.75; = .004), but not with other factors including pleural puncture angle. . For ablations targeting central tumors, steeper pleural puncture angles were associated with fewer major adverse events. For ablations targeting noncentral tumors, the use of MWA and three or more pleural punctures were associated with increased major adverse events. . The findings support applicator insertion with a steep pleural puncture angle during percutaneous ablation of central lung tumors.