| Aims:Radioactive iodine(RAI)is considered to be related with hematologic changes.This study aimed to evaluate influence of the first RAI ablation on peripheral complete blood count(CBC)in patients with differentiated thyroid cancer(DTC).Methods: Data of CBC at baseline and 6 months after RAI were obtained in 385 DTC patients with approximately 3700 MBq 131I(ranging 2220 to 7585 MBq).Further comparison was done in 196 patients with 1-month post-ablation data available.Routine blood examinations were performed to determine impact of RAI on white blood cell(WBC),red blood cell(RBC),hemoglobin,platelet,neutrophil,lymphocyte and monocyte in both sexes.Continuous variables were compared by paired t-tests and independent samples t-test,and categorical variables were compared by chi-square analysis.Data with repeated measurements were analyzed by analysis of variance.Results: 1.Six months after the first RAI therapy,4.16% of patients(n=16)exhibited abnormal WBC,12.99%(n=50)abnormal Hb,11.17%(n=43)abnormal RBC,5.19%(n=20)abnormal platelet,5.97%(n=23)abnormal neutrophil,and 6.75%(n=26)abnormal lymphocyte.Even though the mean remained within the normal reference range during follow-up,significant declines in WBC,platelet,neutrophil and lymphocyte were seen 6 months after RAI ablation.On the contrary,significant increases were seen in RBC and Hb.No significant changes in and monocyte were detected.2.Gender appeared to have little effect on the baseline CBC as no significant differences were detected in the baseline hematologic parameters.There were no significant differences on WBC,platelet,neutrophil,lymphocyte and monocyte changes between male and female when comparing the baseline data with those obtained at 6-month follow-up.Significant differences were found on RBC and Hb changes between males and females.These changes in males were more obvious than in females(0.18±0.28 versus 0.12±0.29×1012/L for RBC,p=0.049;4.71±7.41 versus 1.79±9.21 g/L for Hb,p=0.004).3.Over the range of different administered activities in this study,no significant dose-response relationship was detected in CBC between baseline and follow-up.RAI activity grouping was based on the empiric dosing categories according to our experience: less than 3700 MBq,3700 to 4440 MBq,and more than 4440 MBq.In terms of platelet,a significant difference of the changed value was found between the less than 3700 MBq group and more than 4440 MBq group by post-hoc test(12.88±33.40 versus-3.62±35.71,p=0.032).When data were analyzed by different genders,significant differences in Hb and platelet were seen at 3700 to 4440 MBq levels of administered activities(both p=0.02).By multiple comparison,significant differences were detected in RBC,Hb,platelet between males and females when we compared CBC at baseline with follow up.In specific,in 3700 to 4440 MBq group,rising changes in males were more obvious than in females for RBC and Hb(0.19±0.28 versus 0.11±0.29×1012/L,p=0.04 for RBC;4.81±7.41 versus 1.41±9.18g/L,p=0.002 for Hb).While significant rise was found in the platelet count for male,significant decline was detected for female(4.07±40.17 versus-6.75±33.26×109/L,p=0.01).4.When analyzing CBC findings by age,we did not detect significant CBC changes with increased age groups.Similar results were demonstrated if data were analyzed by male and female separately.By multiple comparison,significant difference was found between male and female in 50-60 years group for platelet(12.00±47.47 versus-3.26±30.82×109/L,p=0.04).In 40-50 years group,significant differences were detected in RBC and Hb between male and female(0.28±0.30 versus 0.11±0.29×1012/L,p=0.02 for RBC;6.84±8.38 versus 1.86±7.23g/L,p=0.02 for Hb).5.The CBC values reached a nadir at 1 month post RAI therapy.For example,the decrease of WBC from baseline value was 12.69% and 7.11% at 1 and 6 months after RAI therapy(both p<0.001).Interestingly,significant declines were presented in RBC and Hb 1 months after the first RAI treatment.However,6 months later,significant rises were found in RBC and Hb,even higher than baseline values.Conclusions: WBC and platelet decreased obviously one month after RAI.While they partly recovered 6 months after RAI,they were still lower than the baseline.However,RBC and hemoglobin transiently decreased at 1 month and then increased to levels even higher than baseline 6 months later.At 3700 to 4440 MBq of RAI,the decline of platelet in females was more obvious than in males.Yet,rises of RBC and hemoglobin in males were higher than in females.The risks associated with these changes are unlikely to outweigh the potential benefits of RAI in DTC patients. |
