PDF(Pubmed)
Abstract：
General radiotherapeutic management for >10 brain metastases (BMs) totaling >100 cm3, including multiple large lesions (>10-30 cm3) in close proximity, demonstrated limited efficacy and/or safety. We describe a case of 12 BMs, summating 122.2 cm3, including a 39.6 cm3 maximum lesion and adjacent ones. The patient had an 8.1-year treatment history for recurrent/metastatic breast cancer refractory to endocrine and chemotherapy. BMs were treated with conventional whole-brain radiotherapy (WBRT) with 30 Gy/10 fractions (fr), followed by an immediate stereotactic radiosurgery (SRS) boost with 27 Gy/5 fr (52-64% isodoses) which covers the gross tumor boundaries of selected eight lesions (total 118.4 cm3). The SRS dose was defined to ensure the cumulative biologically effective dose (BED10) of just ≥80 Gy while minimizing the risk of radiation injury. The SRS was performed using a CyberKnife (CK) robotic system (Accuray Incorporated, Sunnyvale, California, United States) with a variable-sized collimator (10-40 mm), for which en bloc consecutive irradiation, using 215 beams based on a comprehensively optimized single plan (path), was adopted. The treatment time per fraction was ≤45 min (mean 5.6 min per lesion). Afterward, BMs demonstrated remarkable regression over six months, causing the total residual visible lesions of 12.6 cm3 (10.3%) at 11.4 months, despite the absence of obvious lesion shrinkage during the radiotherapy. WBRT, followed by an immediate 5-fr SRS boost with a total BED10 of 80 Gy to large and/or culprit lesions, can be an efficacious and safe treatment option for multiple BMs, totaling >120 cm3. En bloc consecutive irradiation with a single path provides overwhelmingly more efficient delivery for treating multiple lesions using CK in terms of irradiation time and comprehensive reduction of normal brain dose compared to individual planning. Volumetric-modulated arc-based >10-fr SRS with simultaneously integrated reduced-dose WBRT may be an alternative to further enhance efficacy and safety.
摘要：
>10个脑转移瘤（BMs）总>100cm3的一般放射治疗管理，包括近距离的多个大病灶（>10-30cm3），显示有限的疗效和/或安全性。我们描述了一个12个弹道导弹的案例，总计122.2cm3，包括39.6cm3的最大病变和相邻病变。该患者有8.1年的复发/转移性乳腺癌治疗史，难以内分泌和化疗。BMs采用30Gy/10分（fr）的常规全脑放疗（WBRT）治疗，随后立即进行立体定向放射外科（SRS）增强，以27Gy/5fr（52-64％等剂量）覆盖选定的8个病变的大体肿瘤边界（总计118.4cm3）。定义SRS剂量以确保累积生物有效剂量（BED10）刚好≥80Gy，同时将辐射损伤的风险降至最低。SRS是使用射波刀(CK)机器人系统(AccurayIncorporated，桑尼维尔,加州,美国）带有可变尺寸的准直器（10-40毫米），对于整体连续辐照，使用基于全面优化的单个计划（路径）的215个波束，被采纳了。每个部分的治疗时间≤45分钟（平均每个病变5.6分钟）。之后,BMS在六个月内表现出显著的回归，在11.4个月时导致12.6cm3（10.3％）的总残留可见病变，尽管放疗期间没有明显的病灶收缩。WBRT,然后立即进行5-frSRS增强，总BED10为80Gy，以达到大的和/或罪魁祸首的病变，可以是多个BM的有效和安全的治疗选择，总计>120cm3。与个人计划相比，使用单一路径的整体连续照射在照射时间和正常脑剂量的全面减少方面，为使用CK治疗多个病变提供了绝对更有效的递送。体积调制的基于电弧的>10-frSRS与同时集成的减少剂量WBRT可能是进一步提高疗效和安全性的替代方案。
