Département de l'Imagerie Médical et Science de l'Information, Geneva University Hospital, 1211, Geneva 14, Switzerland.
J Neurooncol. 2011 Apr;102(2):295-300. doi: 10.1007/s11060-010-0318-2. Epub 2010 Aug 20.
This study was to evaluate the treatment dosimetry, efficacy and toxicity of intensity modulated radiation therapy (IMRT) and fractionated stereotactic radiotherapy (FSRT) in the management of infratentorial ependymoma. Between 1999 and 2007, seven children (median age, 3.1 years) with infratentorial ependymoma were planned with either IMRT (3 patients) or SFRT (4 patients), the latter after conventional posterior fossa irradiation. Two children underwent gross total resection. Median prescribed dose was 59.4 Gy (range, 55.8-60). The median follow-up for surviving patients was 4.8 years (range, 1.3-8). IMRT (median dose, 59.4 Gy) and FSRT (median dose, 55.8 Gy) achieved similar optimal target coverage. Percentages of maximum doses delivered to the cochleae (59.5 vs 85.0% Gy; P = 0.05) were significantly inferior with IMRT, when compared to FSRT planning. Percentages of maximum doses administered to the pituitary gland (38.2 vs 20.1%; P = 0.05) and optic chiasm (38.1 vs 14.1%; P = 0.001) were, however, significantly higher with IMRT, when compared to FSRT planning. No recurrences were observed at the last follow-up. The estimated 3-year progression-free survival and overall survival were 87.5 and 100%, respectively. No grade >1 acute toxicity was observed. Two patients presented late adverse events (grade 2 hypoacousia) during follow-up, without cognitive impairment. IMRT or FSRT for infratentorial ependymomas is effective and associated with a tolerable toxicity level. Both treatment techniques were able to capitalize their intrinsic conformal ability to deliver high-dose radiation. Larger series of patients treated with these two modalities will be necessary to more fully evaluate these delivery techniques.
本研究旨在评估调强放疗（IMRT）和分次立体定向放疗（FSRT）在小脑幕下室管膜瘤治疗中的剂量学、疗效和毒性。1999 年至 2007 年间，7 名小脑幕下室管膜瘤患儿（中位年龄 3.1 岁）分别接受 IMRT（3 例）或 FSRT（4 例）治疗，后者在常规后颅窝放疗后进行。2 例患儿行大体全切除。中位处方剂量为 59.4Gy（范围 55.8-60Gy）。生存患儿的中位随访时间为 4.8 年（范围 1.3-8 年）。IMRT（中位剂量 59.4Gy）和 FSRT（中位剂量 55.8Gy）均获得了相似的最佳靶区覆盖。与 FSRT 计划相比，IMRT 时耳蜗接受的最大剂量百分比（59.5%与 85.0%Gy；P=0.05）明显较低。垂体（38.2%与 20.1%；P=0.05）和视交叉（38.1%与 14.1%；P=0.001）接受的最大剂量百分比，然而，IMRT 时明显较高，与 FSRT 计划相比。末次随访时无复发。估计 3 年无进展生存率和总生存率分别为 87.5%和 100%。未观察到 3 级及以上急性毒性。2 例患者在随访期间出现迟发性不良事件（2 级听力下降），但无认知障碍。IMRT 或 FSRT 治疗小脑幕下室管膜瘤有效，且毒性可耐受。两种治疗技术都能够利用其内在的适形能力来给予高剂量放疗。需要更大系列的患者接受这两种治疗方式来更全面地评估这些治疗方法。
