Clinical and Paraclinical Characteristics, and Treatment Outcomes of I-131-Refractory Differentiated Thyroid Cancer at Vietnam National Cancer Hospital

Abstract

Objective: This research aim to evaluate clinical, paraclinical characteristics and treatment outcomes in patients with I-131 refractory differentiated thyroid cancer at Vietnam National Cancer Hospital (K
hospital).
Methods: descriptive study on 27 patients with differentiated thyroid cancer, I-131 refractory from January 2020 to October 2023.
Results: The mean age of patient was 50.26 ± 15.5 years old; the female/male ratio was 3/1. Histology: 19 patients (70.4%) were papillary, 07 patients (25.9%) were follicular, 01 patient (3.7%) was papillaryfollicular. The mean of treatment dose until defined I-131 refractory was 396.2 ± 156.7mCi. According to the 2015 ATA I-131 refractory criteria, there were 14 patients (51.9%) in group I (no uptake I-131 at the first WBS), 7 patients ( 25.9%) in group II (the tumor tissue loses the ability to concentrate I-131 after previous evidence of I-131-avid disease), 5 patients (18.5%) in group III (I-131 is concentrated in some lesions but not in others), 01 patient (3.7%) in group IV (metastatic disease progresses despite a significant concentration of I-131). There were 04 patients (14.8%) who received surgery for metastatic lesions, 09 patients (33.3%) received further treatment with I-131, 10 patients (37%) did not receive any treatment and continued to follow monitoring and TSH suppression, the remaining 02 patients (7.4%) received external radiotherapy and treated with Lenvatinib. There were 06 patients (22.2%) achieved complete response, 07 patients (25.9%) achieved biochemical incomplete response, 03 patients (11.1%) achieved unclear response, structural incomplete response in 11 patients (40.7%).
Conclusion: I-131 refractory differentiated thyroid cancer is a new area. Treatment requires a combination of methods and individualization. When the disease is widespread, targeted therapy such as Lenvatinib helps improve survival and alleviate symptoms.