Harvard Radiation Oncology Program, Boston, Massachusetts 02114, USA.
Int J Radiat Oncol Biol Phys. 2011 Dec 1;81(5):1428-35. doi: 10.1016/j.ijrobp.2010.07.1991. Epub 2010 Oct 8.
Given the excellent prognosis for patients with benign meningiomas, treatment strategies to minimize late effects are important. One strategy is proton radiation therapy (RT), which allows less integral dose to normal tissue and greater homogeneity than photon RT. Here, we report the first series of proton stereotactic radiosurgery (SRS) used for the treatment of meningiomas.
We identified 50 patients with 51 histologically proven or image-defined, presumed-benign meningiomas treated at our institution between 1996 and 2007. Tumors of <4 cm in diameter and located≥2 mm from the optic apparatus were eligible for treatment. Indications included primary treatment (n=32), residual tumor following surgery (n=8), and recurrent tumor following surgery (n=10). The median dose delivered was 13 Gray radiobiologic equivalent (Gy[RBE]) (range, 10.0-15.5 Gy[RBE]) prescribed to the 90% isodose line.
Median follow-up was 32 months (range, 6-133 months). Magnetic resonance imaging at the most recent follow-up or time of progression revealed 33 meningiomas with stable sizes, 13 meningiomas with decreased size, and 5 meningiomas with increased size. The 3-year actuarial tumor control rate was 94% (95% confidence interval, 77%-98%). Symptoms were improved in 47% (16/34) of patients, unchanged in 44% (15/34) of patients, and worse in 9% (3/34) of patients. The rate of potential permanent adverse effects after SRS was 5.9% (3/51 patients).
Proton SRS is an effective therapy for small benign meningiomas, with a potentially lower rate of long-term treatment-related morbidity. Longer follow-up is needed to assess durability of tumor control and late effects.
鉴于良性脑膜瘤患者的预后极佳，因此采用能够尽量减少晚期效应的治疗策略非常重要。其中一种策略是质子放射治疗（RT），它可以使正常组织的积分剂量更小，且比光子 RT 更均匀。在此，我们报告了首次用于治疗脑膜瘤的质子立体定向放射外科（SRS）系列。
我们在机构中识别了 1996 年至 2007 年间治疗的 50 例 51 个经组织学证实或影像学定义的、疑似良性脑膜瘤患者。肿瘤直径<4cm 且距视器≥2mm 者有资格接受治疗。治疗适应证包括：原发性治疗（n=32）、手术后残留肿瘤（n=8）和手术后复发肿瘤（n=10）。中位给予的剂量为 13 格雷生物等效剂量（Gy[RBE]）（范围 10.0-15.5 Gy[RBE]），规定在 90%等剂量线处。
中位随访时间为 32 个月（范围 6-133 个月）。在最近的随访或进展时的磁共振成像上，33 个脑膜瘤大小稳定，13 个脑膜瘤缩小，5 个脑膜瘤增大。3 年肿瘤控制的实际 actuarial 率为 94%（95%置信区间，77%-98%）。47%（16/34）的患者症状改善，44%（15/34）的患者症状无变化，9%（3/34）的患者症状恶化。SRS 后潜在永久性不良反应的发生率为 5.9%（51 例患者中有 3 例）。
质子 SRS 是治疗小型良性脑膜瘤的有效方法，其长期治疗相关发病率可能较低。需要更长时间的随访来评估肿瘤控制和晚期效应的耐久性。
