AUTHOR=Lan Wei , Renjie Wang , Qichang Wan , Feiyue Teng , Qingjie Ma , Bin Ji 

TITLE=Preoperative Use of Intravenous Contrast Media Is Associated With Decreased Excellent Response Rates in Intermediate-Risk DTC Patients Who Subsequently Receive Total Thyroidectomy and Low-Dose RAI Therapy

JOURNAL=Frontiers in Oncology

VOLUME=10

YEAR=2020

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2020.01297

DOI=10.3389/fonc.2020.01297

ISSN=2234-943X

ABSTRACT=<p><bold>Purpose:</bold> To evaluate the impact of preoperative use of intravenous contrast media (ICM) on the excellent response (ER) rates in a cohort of intermediate-risk differentiated thyroid cancer (DTC) patients who received total thyroidectomy (TT) and low-dose radioactive iodine (RAI) therapy.</p><p><bold>Methods:</bold> A total of 683 consecutive patients were retrospectively reviewed in a single center between August 2016 and August 2018. Patients were divided into ICM group (<italic>n</italic> = 532) and non-ICM group (<italic>n</italic> = 151). Intravenous contrast media patients were 1:1 propensity matched to non-ICM patients based on T stage, N stage, and urinary iodine. Risk-adjusted logistic regression models were constructed to assess the association between the use of ICM and ER rates.</p><p><bold>Results:</bold> Intravenous contrast media patients had significantly higher T stage (<italic>P</italic> &lt; 0.001), N stage (<italic>P</italic> &lt; 0.001), urinary iodine (<italic>P</italic> &lt; 0.001), and ps-Tg (<italic>P</italic> = 0.042) than non-ICM patients. Preoperative use of ICM was found to be significantly associated with decreased ER rates in both the primary cohort [odds ratio (OR) = 0.47, 95% confidence interval (CI) = 0.32–0.71; <italic>P</italic> &lt; 0.001] and the matched cohort (OR = 0.48, 95% CI = 0.25–0.94; <italic>P</italic> = 0.031). Subgroup analysis on RAI delay time in the primary cohort revealed that ER rates in ICM patients were significantly lower than that of non-ICM patients for 1–2 months (<italic>P</italic> = 0.0245) and &gt;2–3 months (<italic>P</italic> = 0.0221) subgroups, but not for &gt;3–4 months, &gt;4–5 months, and &gt;5–6 months subgroups (all <italic>P</italic> &gt; 0.05). A delay time of &gt;3–4 months exhibited the highest ER rate (63.08%) within the ICM group.</p><p><bold>Conclusions:</bold> Preoperative use of ICM is associated with decreased ER rates in intermediate-risk DTC patients who subsequently receive TT and low-dose RAI therapy. For such patients, if ICM has already been received, an RAI delay time of &gt;3–4 months would seem to be more appropriate to achieve better ER rates.</p>