RESUMO
Objective:To evaluate the efficacy and safety of 125I seeds implantation for lymph nodes metastasis (LNM) from radioactive iodine-refractory differentiated thyroid carcinoma (RAIR-DTC), and to verify the computer three-dimensional treatment planning system (TPS) from the dosimetry accuracy in assisting seeds implantation to treat LNM. Methods:Retrospective analysis was performed on 17 RAIR-DTC patients with LNM admitted to the General Hospital of Northern Theater Command from December 2016 to January 2019 (8 males, 9 females, median age 58 years). All patients underwent preoperative TPS planning design, CT-guided puncture and 125I seeds implantation (seed activity 14.8-25.9 MBq). The dosimetric results of postoperative validation were compared with those of preoperative planning, including the dosimetric parameters such as target volume before and after surgery and the dose received by 90% and 100% gross tumor volume (GTV) ( D90, D100), the percentage received by 100% and 150% of the prescription dose ( V100, V150), homogeneity index (HI). All patients underwent CT after 6 months to compare the LNM size, serum thyroglobulin (Tg) level, and the improvement of complications before and after treatment. Efficacies were divided into complete remission (CR), partial remission (PR), stable disease (SD), and progressive disease (PD). Paired t test or Wilcoxon signed rank test were used to analyze the data. Results:Among 17 patients, a total of 226 125I radioactive seeds were implanted. Among them, 1 achieved CR, 10 achieved PR, 4 were with SD, and 2 were with PD. The diameter of LNM was 1.40(0.65, 3.05) cm before treatment and was 0.40(0.21, 0.91) cm 6 months after treatment ( z=-3.95, P<0.05). The Tg before treatment was 23.50(20.94, 72.92) μg/L and was 8.90(3.20, 40.22) μg/L 6 months after treatment ( z=-5.009, P<0.001). Tg antibody were all negative. There were 90.90% (20/22) of patients had slightly lower D90 than the prescribed dose ((12 378.8±3 182.0) vs (12 497.8±1 686.4) cGy; t=0.251, P>0.05). The postoperative dose parameters D100 and V150 ((6 881.5±1 381.8) cGy, (58.5±18.4)%) were both lower than those of preoperative plan ((8 085.8±2 330.0) cGy, (66.5±17.7)%; t values: 8.913, 3.032, both P<0.05), and the remaining indicators were not significantly different from those of the preoperative plan ( t values: 0.251, 1.493, z values: from -1.604 to -0.593, all P>0.05). Conclusions:According to the TPS preoperative plan, 125I seeds implantation for treating RAIR-DTC LNM can achieve the expected dose distribution, and the short-term tumor local control is effective. It is a safe and effective treatment method.
RESUMO
Objective To evaluate the clinical value of 125I seeds implantation (RSI) for treatment of lymph nodes metastases (LNM) in patients with 131I refractory differentiated thyroid carcinoma (RAIR-DTC).Methods A total of 42 RAIR-DTC patients with LNM (14 males,28 females,median age 49 years) who underwent RSI guided by CT from January 2015 to June 2016 were retrospectively analyzed.All patients underwent CT and their serum thyroglobulin (Tg) levels were measured 2,4 and 6 months post-treatment.The LNM size and serum Tg levels before and after treatment were compared,and the curative effect of RSI for complications was observed.Paired t test,x2 test,repeated measurement analysis of variance,Spearman correlation analysis were used to analyze the data.Results Two patients (4.76％) achieved complete remission,9(21.43％) achieved partial remission,29(69.05％) had no change,2(4.76％) were with progressive disease in all 42 patients.Thetotal effective rate was 95.24％ (40/42).The LNM diameter post-treatment was (1.39±0.75) cm,significantly lower than that before treatment ((1.99±0.38) cm;t=5.557,P＜0.01).The Tg level 2,4 and 6 months posttreatment was (53.24± 14.05),(33.17±7.61) and (25.93± 10.91) μg/L,respectively,which was significantly lower than that before treatment ((57.72± 15.23) μg/L;F =23.612,all P＜0.05).The age,sex,metastatic site,and the number of seeds implanted in each lesion were not the influencing factors on RSI (x2 values:0.569-15.884,rs =0.277,all P＞0.05).The LNM size was the influencing factor on RSI (x2=4.524,P＜0.05).Conclusions 125I RSI can significantly alleviate the clinical symptoms of RAIR-DTC patients with LNM,and the LNM size has relevance for the treatment effect.The clinical follow-up time of serum Tg level can be extended to 6 months or even longer.