Real-time Dynamic Monitoring the equivalent rate and cumulative dose in Patients with Differentiated Thyroid Cancer after Administration of ^sup 131^I for Therapy by Using a New Equipment

• Published in: The Journal of nuclear medicine (1978) Vol. 58; p. 1143
• Main Authors: Yang, Suyun, Tang, Guohua, Liu, Haiyan, Wu, Zhifang, Li, Sijin
• Format: Journal Article
• Language: English
• Published: New York Society of Nuclear Medicine 01.05.2017
• Subjects: Cancer; Data base management systems; Decay; Decay rate; Dosage; Drug dosages; Equivalence; Informed consent; Lesions; Medical imaging; Metastases; Metastasis; Monitoring; Nuclear medicine; Patients; Real time; Therapy; Thyroid; Thyroid cancer
• ISSN: 0161-5505; 1535-5667

Objectives: The aim of this study was to real-time dynamic monitoring the residual activity in patients with differentiated thyroid cancer (DTC) after administration of 131I for post-operation therapy by using a new equipment. Methods: The institutional review board approved this study and waived the requirement for obtaining informed consent. Twenty-nine DTC patients (6 male/23 female, mean age 44.86 ± 13.03 years) with 131I therapy after operation from Jan, 2016 to Oct, 2016. There were 14 cases of the thyroid remnant 100mCi 131I ablation therapy and 13 cases with 150mCi, 1 case with 200mCi, 1 case with 220 mCi 131I treatment for recurrent and metastatic lesions. Using a new equipment to real-time estimating the remain activity of patients after 131I therapy for 4 days, respectively. Average three dose data for the dose equivalent rate and cumulative dose equivalent were collected per minute, respectively. All the data were saved to the host system's database. And to measure the dose equivalent rate in each patients at 2,4,6,8,10,12,14,16,18,20,22,24,28,32,36,40,44,48,54,60,66,72h after administration of therapeutic doses of 131I, respectively. Results: The total of 80 cases of DTC patients with 131I treatment were monitored. 29 cases with relatively complete data due to the big difference of personal dosimeter, relative position relatively fixed process, such as the monitoring system were leaved from patient's body at night and noon when sleeping, etc. 5 cases with complete real-time monitoring data were researched in this study. The time-dose equivalent rate trend chart for DTC case who administrated 131I therapy showed that the reduce changing of dose equivalent rate was exponential decay (Fig.1 and Fig. 2). Both thyroid remnant and recurrent, metastatic lesions, there was manifest reduced in 54h after serving 131I treatment lower than 200μSv/h. Moreover, the dose equivalent rate of the surface of body lower than 200μSv/h in 48 hours in each patients who was administrated 131I treatment less than 150mCi. Conclusion: The dose equivalent rate reduced as the exponential decay after 131I therapy could be real-time monitored by using the new equipment and hence deserves further investigation.