Barkan A L, Halasz I, Dornfeld K J, Jaffe C A, Friberg R D, Chandler W F, Sandler H M
Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, USA.
J Clin Endocrinol Metab. 1997 Oct;82(10):3187-91. doi: 10.1210/jcem.82.10.4249.
Pituitary irradiation suppresses GH hypersecretion in patients with acromegaly. Within 10 yr after radiotherapy, up to 80% of patients achieve plasma GH levels below 5 micrograms/L. Whether this is sufficient to normalize plasma insulin-like growth factor I (IGF-I) levels, is unknown. We examined the effect of radiotherapy on plasma IGF-I concentrations in patients with acromegaly. We reviewed hospital charts of 140 patients with acromegaly seen in our institution between 1975 and 1996. Data on plasma GH and IGF-I were extracted and tabulated longitudinally together with the information about the concomitant medical therapy. We included data from the patients who received radiotherapy as a part of their treatment and whose IGF-I was monitored for more than 1 yr afterward. To avoid the potential bias, the data for patients who were referred to us for medical therapy, having failed radiation elsewhere, were excluded. A total of 38 datasets were submitted for the final analysis. The average follow-up was 6.8 +/- 0.8 yr (range, 1-19). Only 2 patients achieved age- and sex-adjusted normal IGF-I levels while off medical therapy. Noncured patients had a mean plasma GH level of 4.6 +/- 1.1 micrograms/L but still elevated plasma IGF-I levels (219 +/- 26% of the upper normal limit) at the last follow-up visit. A random GH concentration below 1.5 micrograms/L was associated with a pathologically high plasma IGF-I concentration in 43% of instances. Radiotherapy appears to be ineffective in normalizing plasma IGF-I levels in acromegaly. A multicenter study to reevaluate the future use of this modality in patients with acromegaly is warranted.
垂体放疗可抑制肢端肥大症患者的生长激素（GH）分泌过多。放疗后10年内，高达80%的患者血浆GH水平降至5微克/升以下。这是否足以使血浆胰岛素样生长因子I（IGF-I）水平恢复正常尚不清楚。我们研究了放疗对肢端肥大症患者血浆IGF-I浓度的影响。我们回顾了1975年至1996年间在我们机构就诊的140例肢端肥大症患者的病历。提取了血浆GH和IGF-I的数据，并与伴随治疗的信息一起纵向列表。我们纳入了接受放疗作为治疗一部分且放疗后IGF-I监测超过1年的患者的数据。为避免潜在偏差，排除了因在其他地方放疗失败而转诊至我们这里进行药物治疗的患者的数据。共38个数据集提交进行最终分析。平均随访时间为6.8±0.8年（范围1 - 19年）。只有2例患者在停止药物治疗后达到年龄和性别调整后的正常IGF-I水平。未治愈的患者在最后一次随访时平均血浆GH水平为4.6±1.1微克/升，但血浆IGF-I水平仍升高（是正常上限的219±26%）。在43%的情况下，随机GH浓度低于1.5微克/升与血浆IGF-I浓度病理性升高相关。放疗似乎无法使肢端肥大症患者的血浆IGF-I水平恢复正常。有必要进行一项多中心研究，以重新评估这种治疗方式在肢端肥大症患者中的未来应用。
