Introduction: Radioactive iodine is the effective therapy in thyroid cancer. The aim
of this study is to evaluate the serum tumor markers in patients under the therapy
with radioactive iodine 131.
Material and Methods: 45 cases of female patients aged 16-60 years with thyroid
cancer surgery referred to the nuclear medicine department of Nemazi hospital for
(iodine treatment after surgery) were selected. The selection was on the basis of
interviewing and information of patients is consent forms. Only patients with thyroid
cancer and referred for the first time without any other diseases were chosen for this
study. The selected patients were prescribed a dose of 150 m Ci of I-131. From each
patient, 4 mL of chelated serum for serological studies on tumor markers and 2 mL
of oxalated serum for spectrophotometry studies on cell death were used in three
stages. The first stage before the iodine therapy, the second stage, after 48 hours, and
the third stage, 30 days after radioiodine therapy were studied and the results were
evaluated by the one-way repeated measures ANOVA test.
Results: According to the results of dependent paired T-Test, AFP, in the periods
before, 48 hours and 1 month after radioiodine therapy, respectively were 3.46 ± 1.21
and 3.74 ± 1.37 and 3.76 ± 1.25 (p <0.0005). About CA 19-9 in the periods before,
48 hours and one month after radioiodine therapy, the results were 9.30 ± 6.32, 9.95
± 6.92 (p = 0.040) and 11.26 ± 7.49 (p <0.0005) respectively. About CEA, the results
were 1.60 ± 0.60, 1.47 ± 0.55 and 2.23 ± 0.69 (p <0.0005), respectively. In the case
of tumor marker CA 15-3 results were 15.53 ± 6.48 and 1.60 ± 0.60 and 15.68 ± 6.52
(p = 0.014), respectively and in the case of ALP, results were 124.22 ± 5 and 122.2 ±
6 and 116.7 ± 7 (p <0.0005), respectively.
Conclusion: According to the same studies and the acquired results, it can be
concluded that the tumor markers CEA and CA19-9 are more acceptable and
sustainable for monitoring the malignancy and progressive disease in patients with
thyroid cancer. The decreasing ALP is normal and transient. The increase of AFP and
CA15-3 is not even statistically reliable. It is recommended that the period of iodine
therapy and falsely elevated tumor markers can be informed to the doctor, during
the gastrointestinal studies in patients with thyroid cancer, in order to prevent wrong
decisions on the treatment process.
Radioiodine therapy reduces the frequency of circulating tumour cells in patients with differentiated thyroid cancer
