Clinical and imaging factors associated with prolonged ablation time in radiofrequency ablation for early-stage breast cancer.
Radiofrequency ablation (RFA) is a minimally invasive treatment for selected patients with early-stage breast cancer, but ablation time varies substantially. We investigated clinical, imaging, procedural, and pathological factors associated with prolonged ablation time.
We retrospectively analyzed 72 patients who underwent breast RFA at a single institution between April 2024 and November 2025. Clinical variables, ultrasonographic tumor characteristics, mammography-based background breast density, ultrasonography-based puncture-site breast density, initial impedance, maximum power, and temperature were evaluated. Exploratory pathological assessment of stromal predominance was performed in 48 patients.
The median ablation time was 649.5 s (IQR 508.8-879.5). Ablation target size, ultrasonographic tumor dimensions, background density, puncture-site density (p < 0.001), and maximum power were positively associated with ablation time, whereas initial impedance showed a negative correlation. Puncture-site density and initial impedance were strongly inversely correlated (r = -0.716, p < 0.001). Mammography-based background density and ultrasonography-based puncture-site density showed substantial agreement (60/72, 83.3%) and strong ordinal correlation (Spearman r = 0.838, p < 0.001). In multivariable analysis, ablation target size (β = 60.26 s/mm, p = 0.003), initial impedance conditional on puncture-site density (β = 2.89 s/Ω, p = 0.015), and puncture-site density (β = 388.33 s/category, p < 0.001) were independently associated with prolonged ablation time.
Ablation time is influenced by tumor size, local tissue density, impedance, and possibly stromal predominance. Local ultrasonographic assessment complements mammographic density for procedure-specific RFA planning, although prospective validation is required.
We retrospectively analyzed 72 patients who underwent breast RFA at a single institution between April 2024 and November 2025. Clinical variables, ultrasonographic tumor characteristics, mammography-based background breast density, ultrasonography-based puncture-site breast density, initial impedance, maximum power, and temperature were evaluated. Exploratory pathological assessment of stromal predominance was performed in 48 patients.
The median ablation time was 649.5 s (IQR 508.8-879.5). Ablation target size, ultrasonographic tumor dimensions, background density, puncture-site density (p < 0.001), and maximum power were positively associated with ablation time, whereas initial impedance showed a negative correlation. Puncture-site density and initial impedance were strongly inversely correlated (r = -0.716, p < 0.001). Mammography-based background density and ultrasonography-based puncture-site density showed substantial agreement (60/72, 83.3%) and strong ordinal correlation (Spearman r = 0.838, p < 0.001). In multivariable analysis, ablation target size (β = 60.26 s/mm, p = 0.003), initial impedance conditional on puncture-site density (β = 2.89 s/Ω, p = 0.015), and puncture-site density (β = 388.33 s/category, p < 0.001) were independently associated with prolonged ablation time.
Ablation time is influenced by tumor size, local tissue density, impedance, and possibly stromal predominance. Local ultrasonographic assessment complements mammographic density for procedure-specific RFA planning, although prospective validation is required.
Authors
Watanabe Watanabe, Kashiwagi Kashiwagi, Nishikawa Nishikawa, Kochi Kochi, Takada Takada, Tauchi Tauchi, Ogisawa Ogisawa, Kinoshita Kinoshita, Shibutani Shibutani, Morisaki Morisaki
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