Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
Department of Radiology, University of Michigan, Ann Arbor, Michigan.
Int J Radiat Oncol Biol Phys. 2018 Mar 15;100(4):950-958. doi: 10.1016/j.ijrobp.2017.12.014. Epub 2017 Dec 15.
Stereotactic body radiation therapy (SBRT) and radiofrequency ablation (RFA) are widely used therapies for the treatment of intrahepatic metastases; however, direct comparisons are lacking. We sought to compare outcomes for these 2 modalities.
From 2000 to 2015, 161 patients with 282 pathologically diagnosed unresectable liver metastases were treated with RFA (n = 112) or SBRT (n = 170) at a single institution. The primary outcome was freedom from local progression (FFLP). The effect of treatment and covariates on FFLP was modeled using a mixed-effects Cox model with application of inverse probability treatment weighting to adjust for potential imbalances in treatment modality.
The median follow-up period was 24.6 months. Patients receiving SBRT had larger tumors than those treated with RFA (median, 2.7 cm vs 1.8 cm; P < .01). On univariate analysis, tumor size was associated with worse FFLP for RFA (hazard ratio [HR]; 1.57; 95% confidence interval [CI], 1.15-2.14; P < .01) but not for SBRT (HR, 1.38; 95% CI, 0.76-2.51; P = .3). The 2-year FFLP rate was 88.2% compared with 73.9%, favoring SBRT (P = .06). For tumors ≥2 cm in diameter, SBRT was associated with improved FFLP (HR, 0.28; 95% CI, 0.09-0.93; P < .01). On multivariate analysis, treatment with SBRT (HR, 0.21; 95% CI, 0.07-0.62; P = .005) and smaller tumor size (HR, 0.65; 95% CI, 0.47-0.91; P = .01) were associated with improved FFLP. The 2-year overall survival rate was 51.1%, with no difference between groups (P = .8). Grade ≥3 treatment-related toxicity was rare, with no difference between SBRT (n = 4) and RFA (n = 3).
Treatment with SBRT or RFA is well tolerated and provides excellent and similar local control for intrahepatic metastases <2 cm in size. For tumors ≥2 cm in size, treatment with SBRT is associated with improved FFLP and may be the preferable treatment.
立体定向体部放射治疗（SBRT）和射频消融（RFA）是治疗肝内转移的广泛应用的治疗方法；然而，缺乏直接比较。我们旨在比较这两种方法的结果。
2000 年至 2015 年，在一家机构治疗了 161 名患有 282 个经病理诊断为不可切除的肝转移的患者，分别接受 RFA（n=112）或 SBRT（n=170）治疗。主要结局是无局部进展（FFLP）。使用混合效应 Cox 模型来模拟治疗和协变量对 FFLP 的影响，并应用逆概率治疗加权来调整治疗方式的潜在不平衡。
中位随访时间为 24.6 个月。接受 SBRT 的患者肿瘤大于接受 RFA 的患者（中位数，2.7cm 与 1.8cm；P<.01）。单因素分析显示，肿瘤大小与 RFA 的 FFLP 较差相关（风险比[HR]，1.57；95%置信区间[CI]，1.15-2.14；P<.01），但与 SBRT 无关（HR，1.38；95%CI，0.76-2.51；P=0.3）。2 年 FFLP 率为 88.2%，而 SBRT 为 73.9%，SBRT 更优（P=0.06）。对于直径≥2cm 的肿瘤，SBRT 与改善的 FFLP 相关（HR，0.28；95%CI，0.09-0.93；P<.01）。多因素分析显示，SBRT 治疗（HR，0.21；95%CI，0.07-0.62；P=0.005）和肿瘤较小（HR，0.65；95%CI，0.47-0.91；P=0.01）与改善的 FFLP 相关。2 年总生存率为 51.1%，组间无差异（P=0.8）。≥3 级与治疗相关的毒性反应罕见，SBRT（n=4）和 RFA（n=3）之间无差异。
SBRT 或 RFA 治疗耐受良好，为大小<2cm 的肝内转移提供了极好且相似的局部控制。对于直径≥2cm 的肿瘤，SBRT 治疗与改善的 FFLP 相关，可能是更好的治疗方法。
