Ugur Omer, Bozkurt Murat F, Hamaloglu Erhan, Sokmensuer Cenk, Etikan Ilker, Ugur Yesim, Sayek Iskender, Gulec Seza A
Hacettepe University Medical Center, Ankara, Turkey.
Arch Surg. 2004 Nov;139(11):1175-9. doi: 10.1001/archsurg.139.11.1175.
The kinetics of technetium Tc 99m sestamibi (MIBI) in primary hyperparathyroidism are variable and affected by the cellular size of the abnormal glands, the parathyroid hormone levels, and the functional expression of P-glycoprotein (Pgp). The success of gamma probe-guided parathyroidectomy is closely related to the parathyroid-to-thyroid activity ratio at the time of surgery. Preoperative determination of maximum uptake ratio may improve the surgical outcome.
Thirty-one patients with primary hyperparathyroidism attributed to a solitary parathyroid adenoma (27 patients) or multiglandular hyperplasia (4 patients) underwent dynamic MIBI imaging preoperatively. Maximum MIBI activity and activity elimination half-life in the abnormal parathyroid glands and thyroid glands were measured, and the maximum uptake ratio was calculated. After a second MIBI injection on the day of surgery, all patients underwent gamma probe-guided parathyroidectomy and cervical exploration. Timing of surgery after MIBI injection was individualized according to the optimal time to surgery (time to maximum uptake ratio), which was determined by preoperative scintigraphy. During surgery, the gamma probe was used to measure ex vivo counts of excised lesions and adjacent postexcision normal tissue (background). Image characteristics, MIBI kinetics, and gamma probe findings were correlated with gland volume, oxyphil cell content, Pgp expression, and serum parathyroid hormone levels.
Probe localization of abnormal glands at maximum uptake ratio was successful in all patients. The volume of the parathyroid lesion ranged from 0.03 to 9.8 mL (median, 0.7 mL). Parathyroid maximum MIBI activity correlated with the volume of the gland (r = 0.54, P = .002) and serum parathyroid hormone level (r = 0.58, P = .001). No correlation between maximum MIBI activity and oxyphil cell content or Pgp expression could be demonstrated. Elimination half-life of MIBI from parathyroid inversely correlated with Pgp (r = -0.36, P = .05). The ex vivo lesion-background count ratio positively correlated with volume of the gland (r = 0.66, P = .001) and parathyroid hormone level (r = 0.48, P = .006). Ex vivo lesion counts and Pgp expression were negatively correlated (r = -0.37, P = .04).
A strong relationship between volume of the parathyroid gland, serum parathyroid hormone levels, and MIBI uptake exists in primary hyperparathyroidism. Gamma probe-guided localization of abnormal gland(s) can be more successful if surgery is undertaken at maximum uptake ratio. High Pgp expression increases MIBI parathyroid clearance rate, decreases gamma probe counts, and may significantly alter the optimal time to surgery.
锝 Tc 99m 甲氧基异丁基异腈（MIBI）在原发性甲状旁腺功能亢进中的动力学是可变的，且受异常腺体的细胞大小、甲状旁腺激素水平以及 P - 糖蛋白（Pgp）的功能表达影响。γ 探针引导下甲状旁腺切除术的成功与手术时甲状旁腺与甲状腺的活性比值密切相关。术前测定最大摄取率可能会改善手术效果。
31 例原发性甲状旁腺功能亢进患者，病因是单发甲状旁腺腺瘤（27 例）或多腺体增生（4 例），术前接受了动态 MIBI 显像。测量了异常甲状旁腺和甲状腺中的最大 MIBI 活性及活性消除半衰期，并计算了最大摄取率。在手术当天第二次注射 MIBI 后，所有患者均接受了 γ 探针引导下的甲状旁腺切除术和颈部探查。MIBI 注射后的手术时机根据术前闪烁显像确定的最佳手术时间（达到最大摄取率的时间）进行个体化安排。手术过程中，使用 γ 探针测量切除病变及切除后相邻正常组织（背景）的离体计数。图像特征、MIBI 动力学和 γ 探针检查结果与腺体体积、嗜酸性细胞含量、Pgp 表达及血清甲状旁腺激素水平相关。
所有患者在最大摄取率时通过探针成功定位异常腺体。甲状旁腺病变体积范围为 0.03 至 9.8 mL（中位数为 0.7 mL）。甲状旁腺最大 MIBI 活性与腺体体积（r = 0.54，P = 0.002）和血清甲状旁腺激素水平（r = 0.58，P = 0.001）相关。未发现最大 MIBI 活性与嗜酸性细胞含量或 Pgp 表达之间存在相关性。MIBI 从甲状旁腺的消除半衰期与 Pgp 呈负相关（r = -0.36，P = 0.05）。离体病变 - 背景计数比值与腺体体积（r = 0.66，P = 0.001）和甲状旁腺激素水平（r = 0.48，P = 0.006）呈正相关。离体病变计数与 Pgp 表达呈负相关（r = -0.37，P = 0.04）。
在原发性甲状旁腺功能亢进中，甲状旁腺体积、血清甲状旁腺激素水平与 MIBI 摄取之间存在密切关系。如果在最大摄取率时进行手术，γ 探针引导下异常腺体的定位可能更成功。高 Pgp 表达会增加 MIBI 从甲状旁腺的清除率，降低 γ 探针计数，并可能显著改变最佳手术时间。
