Purpose To retrospectively investigate the impact of the electrode array diameter on local tumor progression after lung radiofrequency ablation. Materials and Methods This study included 651 lung tumors treated using multitined expandable electrodes and followed for 6 months. The mean long-axis tumor diameter was 12 mm ± 7 (range, 2-42 mm). The difference between electrode array diameter and tumor diameter (DAT) was used to investigate the impact of the electrode array diameter. All tumors were classified into 2 groups according to various variables including DAT (10 mm or < 10 mm). The primary technique efficacy rates were calculated using Kaplan-Meier analysis and compared between the 2 groups of each variable using the log-rank test. In addition, crude and multivariate multilevel survival analyses were performed by sequentially including DAT and the other variables in 5 models. Results The median DAT for 651 tumors was 12 mm (range, -15 to 24 mm). The technique efficacy rate was significantly lower in the < 10 mm DAT group than in the 10 mm group (P <.001). In the crude and multivariate multilevel survival analyses, < 10 mm DAT was a significant risk factor for local progression in all models except model 5 (P =.067). In the 10 mm group, the technique efficacy rates were not significantly different between the 2 10 mm DAT subgroups (10 to <15 mm DAT vs 15 mm DAT). Conclusions DAT is an important risk factor for local progression. We recommend an electrode that is 10 mm larger than the tumor diameter.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine