The clinical outcome of 153 Graves' disease patients treated with a wide dose range of radioactive iodine-131 (RAI) was analyzed retrospectively. Six to nine months after the first dose of RAI 60 patients (39%) were hypothyroid (or rather thyroxine-substituted) and 26 (17%) were euthyroid, while 67 patients (44%) did not respond properly: in 32 (21%) their antithyroid drug (ATD) dose could be reduced but not withdrawn (partial response) and 35 (23%) remained hyperthyroid or the same dose of ATD was necessary (no response). The outcome did not correspond significantly to the administered activity of RAI (medians 259, 259, 222, and 259 MBq for hypothyroid, euthyroid, partial, and no response subgroups, respectively), or the activity retained in the gland at 24 h (medians 127, 105, 143, and 152 MBq). The effect was, however, clearly, and in a stepwise pattern, dependent on initial thyroid volume (17, 26, 33 and 35 ml, P < 0.001) or activity per gram tissue retained at 24 h (6.02, 4.95, 4.75, and 4.44 MBq/g, P = 0.002). Also, higher residual level of thyrotoxicosis at the time of RAI treatment was connected with worse outcome. The dose-dependency of outcome was further analyzed. When our sample was divided into tertiles, according to the adjusted dose, the same modest success rates (47%) were seen in the lower and middle tertiles. However, doses higher than 5.88 MBq/g (the upper tertile) resulted in success rate of 75%. Finer division into decils has shown a threshold-like increase in cure rate between the 7th and the 8th decil. In the first 7 decils (doses ≤ 6 MBq/g) the complete response rate was 45 to 50%, in the 8th decil (6.0 to 7.8~MBq/g) it rose to 80% and was not further increased with increasing dose. Direct comparison of higher (> 6 MBq/g, cure rate 80%) and lower (≤ 6 MBq/g, cure rate 46%) doses gave highly significant difference (P < 0.001). With our dosing range we found a dose-dependent clinical outcome that suggests an optimum delivered dose near 6.5 MBq/g, resulting in successful treatment of ca 80% patients. and J. Čepková, J. Horáček, J. Vižďa, J. Doležal
Úvod: Agranulocytóza je závažná komplikace léčby tyreostatiky (ATD) u zvýšené funkce štítné žlázy. Cílem naší práce bylo zjistit výskyt agranulocytózy u pacientů s Gravesovou nemocí (GD) přijatých k léčbě radioaktivním jodem 131I (RAI) na tyreoidální jednotku naší kliniky. Pacienti a metody: Retrospektivně jsme analyzovali 603 pacientů s GD (500 žen a 103 mužů; průměrný věk 51,5 ? 12,7 let), kterým byl v letech 1999–2012 aplikován RAI. Z nich 327 (54 %) předtím užívalo karbimazol (CBZ), 215 (36 %) methimazol (MMI) a 61 (10 %) propylthiouracil (PTU). Výsledky: Agranulocytóza po ATD byla důvodem k léčbě RAI u 7 z 603 nemocných. Šlo vždy o ženy, s věkovým průměrem 48,7 let (rozpětí 23–78). U 4 pacientek agranulocytóza vznikla po MMI a 3 pacientky užívaly CBZ. Po přepočtu CBZ na odpovídající dávku MMI byla průměrná dávka ATD 22,4 mg MMI/den (rozpětí 9–40). Agranulocytózu po PTU jsme v našem souboru nezachytili. Interval od zahájení terapie ATD do vzniku agranulocytózy byl 20–41 dní. U 5 nemocných došlo k rozvoji teploty, ve 2 případech byla komplikace diagnostikována z rutinní kontroly krevního obrazu. Průměrná doba trvání agranulocytózy byla 5,9 dní (rozpětí 4–8). Závěr: Výskyt agranulocytózy v našem souboru nemocných byl 1,2 %, zatímco literární data uvádějí výskyt 0,2–0,5 %. U všech nemocných došlo k rozvoji agranulocytózy časně, z toho asi 30 % bylo v době diagnózy asymptomatických. Práce má za cíl upozornit na poměrně vzácnou, ale potenciálně závažnou komplikaci léčby ATD. Klíčová slova: agranulocytóza – Gravesova nemoc – karbimazol – methimazol – propylthiouracil, Introduction: Agranulocytosis is a serious complication of antithyroid drugs (ATD) treatment of thyrotoxicosis. The aim of our work was to assess the occurrence of agranulocytosis in Graves’ disease (GD) patients admitted for radioactive iodine 131I (RAI) treatment to our thyroid unit. Patients and methods: We analyzed retrospectively a cohort of 603 GD patients (500 women and 103 men; mean age 51.5 ? 12.7 years) who received RAI between 1999 and 2012. Of them, 327 (54 %) patients were originally treated with carbimazole (CBZ), 215 (36 %) with methimazole (MMI) and 61 (10 %) with propylthiouracil (PTU). Results: Agranulocytosis due to ATD was the cause of RAI treatment in 7 patients of 603. All of them were women (mean age 48.7 years; range 23–78). In 4 patients, agranulocytosis occurred on MMI treatment, and in 3 patients on CBZ. After recalculation of CBZ to the equipotent dose of MMI, the mean ATD dose was 22.4 mg MMI/day (range 9–40). No agranulocytosis due to PTU was found in our cohort. The time from beginning ATD treatment to agranulocytosis was 20–41 days. In 5 patients there was a development of fever, while in 2 patients the complication was diagnosed from routine blood count. The mean duration of agranulocytosis was 5.9 days (range 4–8). Conclusion: Agranulocytosis incidence in our cohort of patients was 1.2 %, while in most reports the prevalence ranged from 0.2 to 0.5 %. In all patients, agranulocytosis occurred early, and in one third it was asymptomatic when found. The aim of our report is to bring attention to a relatively rare, but potentially serious, complication of ATD treatment. Key words: agranulocytosis – carbimazole – Graves’ disease – methimazol – propylthiouracil, and Jitka Čepková, Filip Gabalec, Ioannis Svilias, Jiří Horáček