OBJECTIVES: Owing to ineffective iodine removal, radioiodine dose reduction was recommended in thyroid cancer patients with chronic renal failure. In this study, the radioiodine biodistribution pattern on posttherapy scans in patients with normal renal function and those with chronic renal failure is outlined. METHODS: This study included 10 thyroid cancer patients with chronic renal failure (five females, five males; mean age: 43+/-12.9) and 20 control participants (16 females, four males; mean age: 43.5+/-8.2) with normal renal function. Radioiodine doses used for ablation ranged between 1110 and 3700 MBq in the patient group and between 3700 and 5550 MBq in the control group. Whole-body imaging was performed on day 7 after radioiodine administration. Scans were inspected with regard to oral, nasal, salivary gland, hepatic, mammary, and gastrointestinal uptake patterns. RESULTS: Mild-to-significant liver uptake was present in all patients in the control group, whereas none exhibited gastric uptake. Mild salivary gland, oral or nasal activity was present in a small percentage of patients in the control group. Out of 10 patients with renal failure, eight had salivary gland, nine had gastric, eight had oral uptake linear in pattern that was unresponsive to mouth wash and all had nasal uptake. Six patients reported persistent xerostomia after treatment. Mammary uptake was present in three female patients. Hepatic uptake was faintly visible only in one patient. CONCLUSION: Patients with chronic renal failure exhibited significant salivary gland, oral, nasal, and gastric activity 1 week after radioiodine administration. The linear pattern of oral activity unresponsive to rinsing and persistence of gastric activity for 1 week might suggest adsorption of radioiodine to mucosal cells. Salivary gland dysfunction and the risk of second primary malignancy in iodine-concentrating organs appear as important indications for radioiodine dose reduction in this patient group.
OBJECTIVES: Owing to ineffective iodine removal, radioiodine dose reduction was recommended in thyroid cancerpatients with chronic renal failure. In this study, the radioiodine biodistribution pattern on posttherapy scans in patients with normal renal function and those with chronic renal failure is outlined. METHODS: This study included 10 thyroid cancerpatients with chronic renal failure (five females, five males; mean age: 43+/-12.9) and 20 control participants (16 females, four males; mean age: 43.5+/-8.2) with normal renal function. Radioiodine doses used for ablation ranged between 1110 and 3700 MBq in the patient group and between 3700 and 5550 MBq in the control group. Whole-body imaging was performed on day 7 after radioiodine administration. Scans were inspected with regard to oral, nasal, salivary gland, hepatic, mammary, and gastrointestinal uptake patterns. RESULTS: Mild-to-significant liver uptake was present in all patients in the control group, whereas none exhibited gastric uptake. Mild salivary gland, oral or nasal activity was present in a small percentage of patients in the control group. Out of 10 patients with renal failure, eight had salivary gland, nine had gastric, eight had oral uptake linear in pattern that was unresponsive to mouth wash and all had nasal uptake. Six patients reported persistent xerostomia after treatment. Mammary uptake was present in three female patients. Hepatic uptake was faintly visible only in one patient. CONCLUSION:Patients with chronic renal failure exhibited significant salivary gland, oral, nasal, and gastric activity 1 week after radioiodine administration. The linear pattern of oral activity unresponsive to rinsing and persistence of gastric activity for 1 week might suggest adsorption of radioiodine to mucosal cells. Salivary gland dysfunction and the risk of second primary malignancy in iodine-concentrating organs appear as important indications for radioiodine dose reduction in this patient group.