Quillo Amy R, Bumpous Jeffery M, Goldstein Richard E, Fleming Muffin M, Flynn Michael B
Division of Otolaryngology, Department of Surgery, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA.
Am Surg. 2011 Apr;77(4):484-7.
The 20 per cent rule proposed by Norman established a guideline using radioactivity in the minimally invasive radioguided parathyroidectomy (MIRP) technique to localize and confirm removal of an abnormal parathyroid gland in patients with primary hyperparathyroidism. If radioactivity in the resected gland was at least 20 per cent of excision site/background radioactivity, the 20 per cent rule was satisfied. Patients meeting these criteria underwent unilateral MIRP without intraoperative parathyroid hormone assay or intraoperative frozen section. The study aim was to independently evaluate the 20 per cent rule in MIRP patients with primary hyperparathyroidism. Using the University of Louisville Parathyroid Database from January 1, 1999 to December 31, 2007, 216 MIRP patients with complete radioguided and postoperative management data were identified. The average percentage of ex vivo parathyroid gland radioactivity compared with excision site/background radioactivity was 107 per cent with a range from 14 to 388 per cent. For 99 per cent (196/198) radioactivity recorded from the excised gland was at least 20 per cent of radioactivity recorded from the excision site. Normocalcemia was documented in 98.5 per cent (195/198) at 12 month follow-up. Our data supports the 20 per cent rule in that in 99 per cent of MIRP patients the resected gland radioactivity was at least 20 per cent of excision site radioactivity allowing localization and confirmation of an overactive gland without intraoperative parathyroid hormone monitoring or tissue analysis.
诺曼提出的20%规则建立了一个指导方针，该方针在微创放射性引导甲状旁腺切除术（MIRP）技术中使用放射性，以定位并确认原发性甲状旁腺功能亢进患者异常甲状旁腺的切除情况。如果切除腺体中的放射性至少为切除部位/背景放射性的20%，则满足20%规则。符合这些标准的患者接受了单侧MIRP，术中未进行甲状旁腺激素测定或术中冰冻切片检查。该研究的目的是独立评估原发性甲状旁腺功能亢进MIRP患者的20%规则。利用路易斯维尔大学甲状旁腺数据库，从1999年1月1日至2007年12月31日，确定了216例具有完整放射性引导和术后管理数据的MIRP患者。离体甲状旁腺腺体放射性与切除部位/背景放射性相比的平均百分比为107%，范围为14%至388%。对于99%（196/198）的病例，切除腺体记录的放射性至少为切除部位记录放射性的20%。在12个月的随访中，98.5%（195/198）的患者记录到血钙正常。我们的数据支持20%规则，因为在99%的MIRP患者中，切除腺体的放射性至少为切除部位放射性的20%，从而无需术中甲状旁腺激素监测或组织分析即可定位并确认过度活跃的腺体。
