Departments of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota.
Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota.
Neurosurgery. 2021 Mar 15;88(4):E330-E335. doi: 10.1093/neuros/nyaa555.
Hypopituitarism is the most frequent complication after pituitary adenoma stereotactic radiosurgery (SRS) and is correlated with increasing radiation to the pituitary gland. Biological effective dose (BED) is a dosimetric parameter that incorporates a time component to adjust for mechanisms of deoxyribonucleic acid repair activated during treatment.
To assess mean gland BED as a predictor of post-SRS hypopituitarism, as compared to mean gland dose, in a contemporary cohort study of patients undergoing single-fraction SRS for pituitary adenoma.
Cohort study of 97 patients undergoing single-fraction SRS from 2007 to 2014. Eligible patients had no prior pituitary irradiation, normal pre-SRS endocrine function, and >24 mo of endocrine follow-up. Cox proportional hazards analysis was used to assess mean gland dose and BED as predictors of new post-SRS hypopituitarism.
Median post-SRS follow-up was 48 mo (interquartile range [IQR], 34-68). A total of 27 patients (28%) developed new hypopituitarism at a median 22 mo (IQR, 12-36). Actuarial rates of new endocrinopathy were 17% at 2 yr (95% CI 10%-25%) and 31% at 5 yr (95% CI 20%-42%). On univariate analysis, sex (P = .02), gland volume (P = .03), mean gland dose (P < .0001), and BED significantly predicted new hypopituitarism (P < .0001). After adjusting for sex and gland volume, BED > 45 Gy2.47 and mean gland dose > 10 Gy were significantly associated increased risk of hypopituitarism (hazard ratio [HR] = 14.32, 95% CI = 4.26-89.0, P < .0001; HR = 11.91, 95% CI = 3.54-74.0, P < .0001).
BED predicted hypopituitarism more reliably than mean gland dose after pituitary adenoma SRS, but additional studies are needed to confirm these results.
垂体腺瘤立体定向放射外科（SRS）后最常见的并发症是垂体功能减退症，且与垂体接受的放射剂量增加相关。生物有效剂量（BED）是一种剂量学参数，其中纳入了时间成分，以调整治疗期间激活的脱氧核糖核酸修复机制。
在一项对 97 例垂体腺瘤患者行单次分割 SRS 的当代队列研究中，与垂体剂量相比，评估腺体重均 BED 作为 SRS 后垂体功能减退症的预测指标。
对 2007 年至 2014 年期间行单次分割 SRS 的 97 例患者进行队列研究。符合条件的患者均无既往垂体放疗史、SRS 前内分泌功能正常、且随访时间＞24 个月。采用 Cox 比例风险分析评估腺体重均剂量和 BED 作为预测新发生 SRS 后垂体功能减退症的指标。
中位 SRS 后随访时间为 48 个月（四分位距 [IQR]，34-68）。共有 27 例患者（28%）在中位时间 22 个月（IQR，12-36）时新出现垂体功能减退症。新发生内分泌疾病的 2 年 actuarial 发生率为 17%（95% CI，10%-25%），5 年 actuarial 发生率为 31%（95% CI，20%-42%）。单因素分析显示，性别（P=.02）、腺体体积（P=.03）、腺体重均剂量（P＜.0001）和 BED（P＜.0001）显著预测新发生垂体功能减退症。在校正性别和腺体体积后，BED＞45 Gy2.47 和腺体重均剂量＞10 Gy 与垂体功能减退症风险增加显著相关（危险比 [HR]＝14.32，95% CI＝4.26-89.0，P＜.0001；HR＝11.91，95% CI＝3.54-74.0，P＜.0001）。
在垂体腺瘤 SRS 后，BED 比腺体重均剂量更可靠地预测垂体功能减退症，但还需要进一步的研究来证实这些结果。
