Pham Christopher J, Chang Steven D, Gibbs Iris C, Jones Pamela, Heilbrun M Peter, Adler John R
Department of Neurosurgery, Stanford University Medical Center, 300 Pasteur Drive, Stanford, CA 94305, USA.
Neurosurgery. 2004 Apr;54(4):799-810; discussion 810-2. doi: 10.1227/01.neu.0000114261.18723.6a.
The limited radiation tolerance of the optic nerves and the optic chiasm makes it a challenge to treat immediately adjacent lesions with radiosurgery. Staged or hypofractionated radiosurgery has the virtue of combining the accuracy and conformality of radiosurgery with the normal tissue-sparing benefits of fractionation. We describe a consecutive series of patients with meningiomas and pituitary adenomas abutting the anterior visual pathways who were treated with staged, image-guided radiosurgery.
Thirty-four patients with either meningiomas (20 patients) or pituitary adenomas (14 patients) within 2 mm of the optic apparatus were treated. Several patients had previously been treated with conventional fractionated radiotherapy (5 patients) or subtotal surgical resection (23 patients). Radiosurgery was delivered in two to five stages to a cumulative average marginal dose of 20.0 Gy. Visual testing and clinical examinations were performed before treatment and at follow-up intervals beginning at 6 months after treatment.
The mean follow-up period was 29 months (range, 15-62 mo). Pre- and posttreatment vision was unchanged in 20 patients, improved in 10, and worse in 3. One patient died during follow-up as a result of an unrelated cardiac event. Visual loss was accompanied by tumor progression in two cases. In a third patient with a multiply recurrent adrenocorticotropic hormone-secreting pituitary adenoma, injury to one optic nerve occurred after both a prior course of radiotherapy and three separate sessions of radiosurgery.
Staged radiosurgery resulted in high rates of tumor control and preservation of visual function. Ninety-one percent of patients retained their presurgical vision. Staged radiosurgery may be a safe and effective alternative to either surgery or fractionated radiotherapy for selected lesions adjacent to the optic apparatus.
视神经和视交叉的辐射耐受性有限，这使得对视神经和视交叉紧邻部位的病变进行放射外科治疗成为一项挑战。分次放射外科具有将放射外科的准确性和适形性与分次治疗对正常组织的保护作用相结合的优点。我们描述了一系列连续的、紧邻前视觉通路的脑膜瘤和垂体腺瘤患者，他们接受了分次、图像引导的放射外科治疗。
对34例视器2毫米范围内患有脑膜瘤（20例）或垂体腺瘤（14例）的患者进行了治疗。部分患者曾接受过传统分次放疗（5例）或次全手术切除（23例）。放射外科分2至5次进行，累积平均边缘剂量为20.0 Gy。在治疗前以及治疗后6个月开始的随访期间进行视力测试和临床检查。
平均随访期为29个月（范围15 - 62个月）。20例患者治疗前后视力无变化，10例改善，3例恶化。1例患者在随访期间因无关心脏事件死亡。2例视力丧失伴有肿瘤进展。第3例患者为多次复发的促肾上腺皮质激素分泌型垂体腺瘤，在先前的放疗疗程和3次单独的放射外科治疗后，一侧视神经受损。
分次放射外科导致肿瘤控制率高且视觉功能得以保留。91%的患者保留了术前视力。对于视器附近的特定病变，分次放射外科可能是手术或分次放疗的一种安全有效的替代方法。
