Özhan Özdoğan1, Ayşegül Aksu2, Ersoy Doğan3, Ogün Bülbül2, Merih Güray Durak4, Ali İbrahim Sevinç5, Fırat Bayraktar6, Ahmet Ömer İkiz3. 1. Department of Nuclear Medicine, Dokuz Eylül University School of Medicine, Inciralti, 35340, Izmir, Turkey. ozhan.ozdogan@deu.edu.tr. 2. Department of Nuclear Medicine, Dokuz Eylül University School of Medicine, Inciralti, 35340, Izmir, Turkey. 3. Department of Ear Nose Throat and Head and Neck Surgery, Dokuz Eylül University School of Medicine, Inciralti, 35340, Izmir, Turkey. 4. Department of Pathology, Dokuz Eylül University School of Medicine, Inciralti, 35340, Izmir, Turkey. 5. Department of Surgery, Dokuz Eylül University School of Medicine, Inciralti, 35340, Izmir, Turkey. 6. Division of Endocrinology, Department of Internal Medicine, Dokuz Eylül University School of Medicine, Inciralti, 35340, Izmir, Turkey.
Abstract
OBJECTIVES: Radioiodine can be applied for remnant ablation in low and low to intermediate-risk patients with differentiated thyroid cancer (DTC). A controversy still exists about the application time interval of radioiodine following total thyroidectomy. In this study, we investigated the effect of radioiodine (RAI) therapy timing on the success rates of the ablation. METHODS: We retrospectively reviewed the data of DTC patients who underwent total thyroidectomy and were treated with radioiodine remnant ablation during 2013-2017. Because the objective of this study was to determine the success of ablation according to the postoperative RAI therapy timing, any patients with a pathologic uptake outside the thyroid bed as well as high-risk patients determined before and at RAI therapy were excluded from the study. Finally, 503 patients with low and low to intermediate-risk groups were included in the study. Successful ablation was defined as no visible focal uptake on the neck on I-131 whole body scan with stimulated thyroglobulin (Tg) level of < 1 ng/mL and a normal or undetectable antithyroglobulin antibody (ATG). The time interval from total thyroidectomy to RAI therapy (titRAI) was calculated as months for each patient. RESULTS: A total of 115 (22.9%) patients were in the low to intermediate-risk group whereas most of the patients were at the low-risk group according to the American Thyroid Association (ATA) 2015. Successful ablation was observed in 388 (77.1%) patients. The titRAI was ≤ 3 months in 151 (30.0%) patients and > 3 months in 352 (70.0%) patients. The ratio of successful ablation was statistically higher in patients with a titRAI > 3 months (81.2% of patients) than in patients with ≤ 3 months (67.5% of patients) (χ2 11.247, p 0.001). The rate of successful ablation was 20.3% higher in patients treated after 3 months. There was no statistical difference when titRAI cut off was reduced to 2 months (p > 0.5). CONCLUSION: Investigated the effect of radioiodine therapy initiated before 3 months after total thyroidectomy and it seems to decrease ablation success.
OBJECTIVES:Radioiodine can be applied for remnant ablation in low and low to intermediate-risk patients with differentiated thyroid cancer (DTC). A controversy still exists about the application time interval of radioiodine following total thyroidectomy. In this study, we investigated the effect of radioiodine (RAI) therapy timing on the success rates of the ablation. METHODS: We retrospectively reviewed the data of DTC patients who underwent total thyroidectomy and were treated with radioiodine remnant ablation during 2013-2017. Because the objective of this study was to determine the success of ablation according to the postoperative RAI therapy timing, any patients with a pathologic uptake outside the thyroid bed as well as high-risk patients determined before and at RAI therapy were excluded from the study. Finally, 503 patients with low and low to intermediate-risk groups were included in the study. Successful ablation was defined as no visible focal uptake on the neck on I-131 whole body scan with stimulated thyroglobulin (Tg) level of < 1 ng/mL and a normal or undetectable antithyroglobulin antibody (ATG). The time interval from total thyroidectomy to RAI therapy (titRAI) was calculated as months for each patient. RESULTS: A total of 115 (22.9%) patients were in the low to intermediate-risk group whereas most of the patients were at the low-risk group according to the American Thyroid Association (ATA) 2015. Successful ablation was observed in 388 (77.1%) patients. The titRAI was ≤ 3 months in 151 (30.0%) patients and > 3 months in 352 (70.0%) patients. The ratio of successful ablation was statistically higher in patients with a titRAI > 3 months (81.2% of patients) than in patients with ≤ 3 months (67.5% of patients) (χ2 11.247, p 0.001). The rate of successful ablation was 20.3% higher in patients treated after 3 months. There was no statistical difference when titRAI cut off was reduced to 2 months (p > 0.5). CONCLUSION: Investigated the effect of radioiodine therapy initiated before 3 months after total thyroidectomy and it seems to decrease ablation success.
Authors: Ralf Paschke; Thomas Lincke; Stefan P Müller; Michael C Kreissl; Henning Dralle; Martin Fassnacht Journal: Dtsch Arztebl Int Date: 2015-06-26 Impact factor: 5.594