Department of Neurosurgery, University of Tuebingen Medical Center, Germany.
J Neurosurg. 2010 Dec;113 Suppl:153-59.
Causes of pituitary insufficiencies as a side effect of Gamma Knife surgery (GKS) following irradiation of the hypothalamopituitary axis are still under debate. In an investigation of pituitary insufficiencies after GKS, the authors' main focus is on what role can be attributed to the hypothalamus with regard to endocrinological changes in hypothalamopituitary function following GKS.
A total of 108 patients consecutively treated between April 1992 and July 2003 were included in this retrospective study. All patients had undergone either transsphenoidal or transcranial surgery prior to GKS. The spot dosimetry method was used to determine doses delivered to structures of the hypothalamopituitary axis. For statistical analyses, endocrine insufficiency and deterioration in pituitary function were defined as a decrease in hormonal blood levels below the normal range for 1 or more anterior pituitary lobe hormones. Additionally, an analysis of the rate of patients requiring hormone replacement therapy after GKS due to new endocrinopathies was performed.
Complete patient records of 61 male and 47 female patients with a mean age of 51.9 years (range 9.1–81.2 years) were available for our investigation. The overall tumor control rate was 97% and the endocrinological cure rate was 61.2%. Mean treatment doses in patients with and without new endocrine insufficiencies (shown as with/without insufficiencies and followed by probability values) were as follows: 1.3/0.8 Gy to the hypothalamus(p = 0.2); 2.2/1.6 Gy to the median eminence (p = 0.1); 6.5/4.1 Gy to the pituitary stalk (p = 0.004); and 12.4/9.5Gy to the pituitary gland (p = 0.05). The median overall duration of follow-up after GKS was 6.7 years, with 84 patients(77.7%) whose follow-up was longer than 12 months. The median follow-up time after GKS in patients who developed a new pituitary dysfunction was 79.5 months (6.6 years, SD 3.8 years), and the median follow-up time inpatients with no new insufficiencies was 78.4 months (6.5 years, SD 4 years).
Gamma Knife surgery is a safe and effective treatment for patients with residual and recurrent pituitary adenomas. The rate of pituitary insufficiencies after GKS is still lower than that after conventional radiotherapy.Very low radiation doses are directed to the hypothalamus, and thus this structure does not play a major role in the development of pituitary insufficiencies after GKS. The results of this study show that patients in whom the pituitary stalk and pituitary gland receive a high mean point dose are more likely to develop pituitary insufficiencies after GKS than those who receive a lower dose. (DOI: 10.3171/2010.8.GKS10959).
伽玛刀手术（GKS）后作为下丘脑-垂体轴放射治疗的副作用导致垂体功能减退的原因仍存在争议。在对 GKS 后垂体功能减退的研究中，作者的主要关注点是下丘脑在 GKS 后下丘脑-垂体功能内分泌变化中可以发挥什么作用。
本回顾性研究共纳入 1992 年 4 月至 2003 年 7 月连续治疗的 108 例患者。所有患者均在 GKS 前行经蝶窦或经颅手术。采用点剂量法确定给予下丘脑-垂体轴结构的剂量。为了进行统计学分析，内分泌功能减退和垂体功能恶化被定义为一种或多种前叶激素的激素血液水平下降到正常值以下。此外，还分析了由于新发生的内分泌疾病而需要在 GKS 后进行激素替代治疗的患者的比例。
我们的研究共纳入了 61 名男性和 47 名女性患者的完整病历，平均年龄为 51.9 岁（范围为 9.1-81.2 岁）。总的肿瘤控制率为 97%，内分泌学治愈率为 61.2%。有和无新发内分泌功能减退的患者的平均治疗剂量（分别表示为有/无功能减退和概率值）如下：下丘脑为 1.3/0.8 Gy（p = 0.2）；正中隆起为 2.2/1.6 Gy（p = 0.1）；垂体柄为 6.5/4.1 Gy（p = 0.004）；垂体为 12.4/9.5 Gy（p = 0.05）。GKS 后总的中位随访时间为 6.7 年，84 例（77.7%）患者的随访时间超过 12 个月。新发垂体功能障碍患者的 GKS 后中位随访时间为 79.5 个月（6.6 年，标准差 3.8 年），无新发功能减退患者的中位随访时间为 78.4 个月（6.5 年，标准差 4 年）。
伽玛刀手术是治疗残留和复发性垂体腺瘤患者的安全有效方法。GKS 后垂体功能减退的发生率仍低于传统放疗。下丘脑仅接受极低剂量的辐射，因此在 GKS 后发生垂体功能减退的过程中，该结构不起主要作用。本研究结果表明，接受高平均点剂量垂体柄和垂体的患者比接受低剂量患者更有可能在 GKS 后发生垂体功能减退。（DOI：10.3171/2010.8.GKS10959）
