Ernst-Stecken Antje, Ganslandt Oliver, Lambrecht Ulrike, Sauer Rolf, Grabenbauer Gerhard
Department of Radiation Therapy and Novalis Shaped Beam Surgery Center, University of Erlangen, Germany.
Radiother Oncol. 2006 Oct;81(1):18-24. doi: 10.1016/j.radonc.2006.08.024. Epub 2006 Sep 15.
To prospectively evaluate efficacy and side effects of hypofractionated stereotactic radiotherapy (hfSRT) for irresectable brain metastases not amenable to radiosurgery (SRS).
From 1/2003 to 2/2005, 51 patients with 72 brain metastases were included in a prospective phase II-trial and accepted for treatment at the dedicated stereotactic radiosurgery system Novalis (BrainLAB, Heimstetten, Germany). In case of planned or prior whole brain radiotherapy (WBRT), hfSRT was to be performed with 5 x 6 Gy, otherwise with 5 x 7 Gy. This dose was prescribed to the 90% isodose line which should cover 100% of the planning target volume (PTV).
Rates of complete remission (CR), partial remission (PR), no change (NC) and progressive disease (PD) were 66.7%, 18.1%, 12.5% and 2.8%, respectively, after a median follow-up of 7 months. Median survival was 11 months. Disease-specific survival and survival related to brain metastases were strongly associated with the size of gross tumor volume (GTV), the planning target volume (PTV), Karnofsky Performance Score (KPS) and number of metastases. Side effects, i.e., increase in T2w-signal area, duration of steroid intake and size of new or progressive necrotic centre of metastasis, were dependent on the volume of normal brain irradiated with more than 4 Gy per fraction (V(4Gy)). Significantly more patients with a V(4Gy)> or =23 cc developed radiological signs of side effects from hfSRT.
Hypofractionated stereotactic radiotherapy with 5 x 6-7 Gy is an effective and safe treatment for brain metastases not amenable to single high-dose radiosurgery. The normal brain volume receiving >4 Gy per fraction may not exceed 20 cc.
前瞻性评估大分割立体定向放射治疗（hfSRT）对不适用于放射外科手术（SRS）的不可切除脑转移瘤的疗效和副作用。
从2003年1月至2005年2月，51例患有72个脑转移瘤的患者被纳入一项前瞻性II期试验，并在专用的立体定向放射外科系统Novalis（德国海姆斯泰滕BrainLAB公司）接受治疗。如果计划进行或之前已进行过全脑放疗（WBRT），则hfSRT采用5×6 Gy进行，否则采用5×7 Gy。该剂量处方给90%等剂量线，该等剂量线应覆盖100%的计划靶体积（PTV）。
中位随访7个月后，完全缓解（CR）、部分缓解（PR）、无变化（NC）和疾病进展（PD）的发生率分别为66.7%、18.1%、12.5%和2.8%。中位生存期为11个月。疾病特异性生存期和与脑转移相关的生存期与大体肿瘤体积（GTV）、计划靶体积（PTV）、卡诺夫斯基性能评分（KPS）和转移灶数量密切相关。副作用，即T2加权信号区域增加、类固醇摄入持续时间以及转移灶新的或进展性坏死中心的大小，取决于每分次接受超过4 Gy照射的正常脑体积（V(4Gy)）。V(4Gy)≥23 cc的患者出现hfSRT副作用放射学征象的明显更多。
采用5×6 - 7 Gy的大分割立体定向放射治疗是治疗不适用于单次高剂量放射外科手术的脑转移瘤的一种有效且安全的方法。每分次接受>4 Gy照射的正常脑体积不应超过20 cc。
