使用 124I PET/CT 序贯扫描进行 131I 治疗计划的转移性甲状腺癌患者的治疗前剂量学。

Pretherapeutic dosimetry in patients affected by metastatic thyroid cancer using 124I PET/CT sequential scans for 131I treatment planning.

机构信息

From the *Department of Medical Physics, Sant'Orsola-Malpighi, Bologna, Italy; †Department of Medical Physics, Velindre Cancer Centre, Cardiff, United Kingdom; ‡Department of Nuclear Medicine, Sant'Orsola-Malpighi, Bologna; §Department of Nuclear Medicine, Santa Maria della Misericordia Hospital, Rovigo; and ¶Department of Radiotherapy, Sant'Orsola-Malpighi, Bologna, Italy; and ∥Department of Radiology, University of Southern California, Los Angeles, CA.

出版信息

Clin Nucl Med. 2014 Aug;39(8):e367-74. doi: 10.1097/RLU.0000000000000490.

DOI:10.1097/RLU.0000000000000490

PMID:24978332

Abstract

PURPOSE

This study evaluates the use of sequential I PET/CT for predicting absorbed doses to metastatic lesions in patients with differentiated thyroid cancer undergoing I therapy.

METHODS

From July 2011 until July 2013, 30 patients with metastatic differentiated thyroid cancer were enrolled. Each participant underwent PET/CT at 4, 24, 48, and 72 hours with 74 MBq of I. Blood samples and whole-body exposure measurements were obtained to calculate blood and red marrow doses. Activity concentrations and lesion volumes obtained from PET/CT were used to evaluate tumor doses with medical internal radiation dose formalism and spheres modeling. Mean administered I therapeutic dose was 5994 MBq (range, 1953-11,455 MBq).

RESULTS

I PET/CT demonstrated all lesions detected by posttherapy I whole-body scans. Mean dose rates for blood, red marrow, and lesions were as follows: 0.07 ± 0.02 mGy/MBq, 0.05 ± 0.02 mGy/MBq, and 46.5 ± 117 mGy/MBq, respectively. Despite the high level of thyroid-stimulating hormone and CT detectable lesions, 15 of 30 patients did not show any abnormal I uptake.

CONCLUSIONS

The quantitative value of I PET/CT allows simple and accurate evaluation of lesion dosimetry following medical internal radiation dose formalism. Negative I PET/CT predicts absence of iodine avidity, potentially allowing avoidance of therapeutically ineffective I administration.

摘要

目的

本研究评估了在接受碘-131 治疗的分化型甲状腺癌患者中，使用序贯 I PET/CT 预测转移性病变吸收剂量的效果。

方法

2011 年 7 月至 2013 年 7 月，纳入了 30 例转移性分化型甲状腺癌患者。每位患者均接受了 74MBq 的 I 全身 PET/CT 检查，分别在 4、24、48 和 72 小时进行。采集血样和全身照射测量值，以计算血和红骨髓剂量。从 PET/CT 获得的活性浓度和病变体积用于使用医学内部辐射剂量公式和球体建模来评估肿瘤剂量。平均给予的 I 治疗剂量为 5994MBq（范围，1953-11455MBq）。

结果

I PET/CT 显示了通过碘-131 全身扫描后检测到的所有病变。血液、红骨髓和病变的平均剂量率如下：0.07±0.02mGy/MBq、0.05±0.02mGy/MBq 和 46.5±117mGy/MBq。尽管促甲状腺激素水平高且 CT 可检测到病变，但 30 例患者中有 15 例没有显示任何异常的 I 摄取。