Department of Radiology, Shiga University of Medical Science, Otsu, Japan
Department of Radiology, Shiga University of Medical Science, Otsu, Japan.
Anticancer Res. 2021 May;41(5):2575-2581. doi: 10.21873/anticanres.15036.
BACKGROUND/AIM: Few previous studies have evaluated the effectiveness of single-isocenter multitarget (SIMT) stereotactic radiosurgery (SRS) in clinical practice.
Gross tumor volumes of 113 metastases in 13 patients were measured by contrast-enhanced magnetic resonance imaging. Prescribed doses were set at 20-24 Gy. Based on tumor reduction rates (TRRs) measured before and after SIMT SRS, tumor shrinkage effect was categorized into four grades; almost disappeared: TRR=1, decreased: 0.3≤TRR<1, stable: -0.2<TRR<0.3 and increased: TRR≤-0.2. Tumor shrinkage effects were compared among 3 groups; near group with a distance of <3.2 cm, middle group with a distance of ≥3.2 cm and <6.4 cm, and far group with a distance of ≥6.4 cm, categorized by distance from the isocenter.
Median survival time was 17 months, with 63.7%, 11.5% and 12.4% of metastases corresponded to almost disappeared, decreased and stable, respectively. No significant difference was found in the distribution for TRRs among 3 groups.
Good local control of multiple brain metastases was demonstrated by SIMT SRS, irrespective of distance from the isocenter.
背景/目的：之前很少有研究评估单等中心多靶（SIMT）立体定向放射外科（SRS）在临床实践中的有效性。
对 13 名患者的 113 个转移瘤的大体肿瘤体积进行了增强磁共振成像测量。设定的处方剂量为 20-24 Gy。根据 SIMT SRS 前后测量的肿瘤缩小率（TRR），将肿瘤退缩效果分为四级：几乎消失：TRR=1，减少：0.3≤TRR<1，稳定：-0.2<TRR<0.3，增加：TRR≤-0.2。将距离等中心点<3.2 cm 的近组、距离等中心点≥3.2 cm 且<6.4 cm 的中组和距离等中心点≥6.4 cm 的远组进行分组，比较各组间肿瘤退缩效果。
中位生存时间为 17 个月，几乎消失、减少和稳定的转移瘤分别占 63.7%、11.5%和 12.4%。3 组间 TRR 的分布无显著差异。
SIMT SRS 可实现多发脑转移瘤的良好局部控制，与距等中心点的距离无关。
