177Lu-奥曲肽治疗神经内分泌肿瘤肾脏吸收剂量估算

目的 估算¹⁷⁷Lu-奥曲肽（¹⁷⁷Lu-DOTA-TATE）治疗神经内分泌肿瘤肾脏所受吸收剂量，评估辐射安全并指导治疗。方法 ¹⁷⁷Lu-DOTA-TATE治疗患者行单光子发射断层扫描（single photon emission computed tomography，SPECT）平面显像，勾画计数全身和肾脏区域并转换为活度，构建时间-活度单指数曲线方程，计算全身/肾脏的有效半衰期和累积活度，以MIRD （medical internal radiation dose）方法估算肾脏的吸收剂量。结果 总共11名神经内分泌肿瘤患者进行了18例次¹⁷⁷Lu-DOTA-TATE药物治疗，全身和肾脏的有效半衰期分别为（20.0~99.8）和（38.2~75.2） h，平均有效半衰期分别为（57.3±21.4）和（53.1±2.5） h；肾脏所吸收的剂量为（0.25~1.48） mGy/MBq，平均吸收剂量为（0.90±0.31） mGy/MBq。患者单次疗程肾脏受到的吸收剂量最小1.8 Gy，最大9.6 Gy，多个疗程肾脏受到最大吸收剂量21.7 Gy。结论 准确估算¹⁷⁷Lu-DOTA-TATE治疗神经内分泌肿瘤患者危险器官肾脏吸收剂量，结果低于耐受剂量限值，有望为患者的精准化治疗提供指导。

Estimation of renal absorbed doses in the treatment of neuroendocrine tumors using 177Lu-DOTA-TATE

Objective To estimate the renal absorbed dose in the treatment of neuroendocrine tumors using ¹⁷⁷Lu-DOTA-TATE and to assess the radiation safety and guide the treatment. Methods The dosimetric calculations of patients treated with ¹⁷⁷Lu-DOTA-TATE were carried out based on planar images of single photon emission computed tomography (SPECT). The regions of interest (ROIs) of the whole body and kidneys were delineated and converted into activity. Accordingly, the time-activity curves of the ROIs were obtained. The effective half-lives and cumulative activity of ROIs were calculated through the fitting of a single exponential equation of the ROIs. Then the absorbed doses were calculated based on the medical internal radiation dosimetry (MIRD) formalism. Results A total of 11 patients with neuroendocrine tumors received 18 cycles of treatments with ¹⁷⁷Lu-DOTA-TATE. The effective half-lives of ¹⁷⁷Lu-DOTA-TATE in the whole body and kidneys were 20.0-99.8 h and 38.2-75.2 h, respectively, with an average of (57.3 ±21.4) h and (53.1 ±12.5) h, respectively. The renal absorbed doses of ¹⁷⁷Lu-DTA-TATE were 0.25-1.48 mGy/MBq, with an average of (0.90 ±0.31) mGy/MBq. The minimum and maximum renal absorbed doses in a single treatment cycle were 1.8 Gy and 9.6 Gy, respectively, while the maximum renal absorbed dose in multiple treatment cycles was 21.7 Gy. Conclusions The renal absorbed doses in the treatment of neuroendocrine tumors using ¹⁷⁷Lu-DOTA-TATE were estimated. The result indicate that the renal absorbed doses were lower than the tolerable dose limits. This study is expected to guide the precise treatment of neuroendocrine tumors.