CILJ ISTRAŽIVANJA: Istražiti ishod radiojodne ablacije ostatnog tkiva štitnjače nakon totalne tireoidektomije s ablativnom dozom od 30 mCi J-131 u bolesnika operiranih zbog dobro diferenciranih karcinoma veličine do 4cm, bez ekstratireoidne infiltracije i bez metastaza, te taj ishod usporediti s ishodom ablativne doze od 100 mCi J-131. HIPOTEZE ISTRAŽIVANJA: Ukupna aktivnost J-131 po uspješno provedenoj ablaciji biti će manja u bolesnika u kojih je primijenjena ablativna doza od 30 mCi J-131 nego u bolesnika u kojih je primijenjena ablativna doza od 100 mCi J-131. U većine bolesnika kod kojih je provedena uspješna ablacija s 100 mCi J-131 ista se uspješno mogla provesti i s dozom od 30 mCi J-131. Veću osjetljivost u detekciji ostatnog tkiva štitnjače ima scintigram s J-131 nego tireoglobulin. ISPITANICI I METODE: Provela sam retrospektivno opservacijsko istraživanje u Kliničkom zavodu za nuklearnu medicinu, Kliničkog bolničkog centra Split, u periodu 2008.-2010., uvidom u medicinsku dokumentaciju 108 ispitanika koji su dobili ablativnu dozu od 30 mCi J-131 i 113 ispitanika koji su dobili ablativnu dozu od 100 mCi J-131. Drugi parametar uspješnosti ablacije u navedenim skupinama ispitanika bila je serumska koncentracia Tg prije ablacije i nakon uspješne ablacije. REZULTATI: U 108 ispitanika koji su dobili ablacijsku dozu od 30 mCi J-131, uspješna ablacija je provedena u 85 (79%) ispitanika dok je kod 113 ispitanika koji su dobili ablativnu dozu od 100 mCi J-131 uspješna ablacija provedena u 91 (89%) ispitanika. Prosječna aktivnost po uspješnoj ablaciji u skupini ispitanika koji su dobili ablativnu dozu od 30 mCi J-131 je iznosila 41 mCi, što je 2,6 puta manje nego prosječna doza u skupini ispitanika koji su dobili ablativnu dozu od 100 mCi J-13 gdje je iznosila 107 mCi J-131. Veću osjetljivost u detekciji ostatnog tkiva štitnjače ima scintigram s J-131 nego tireoglobulin (100% vs. 56%). Naime, Tg se mogao koristiti samo kod 125 bolesnika jer je je 45 ispitanika imalo pozitivna tireoglobulinska antitijela a 51 ispitanik, s negativnim tireoglobulinskim antitijelima, je imao negativan nalaz Tg u vrijeme ablacije. Uspjeh ablacije mjeren negativizacijom Tg se nije razlikovao između dviju ablativnih doza (79% u skupini koja je dobila ablativnu dozu od 30 mCi te 84% u skupini koja je dobila ablativnu dozu od 100 mCi) kao niti prosječno smanjenje Tg (0,8 vs. 0,7 ng/mL). Veću osjetljivost u detekciji ostatnog tkiva štitnjače ima scintigram s J-131 nego tireoglobulin (100% vs. 56%). ZAKLJUČCI: Iako je uspjeh ablacije s ablativnom dozom od 30 mCi J-131 za 10% manji nego uspjeh ablacije s ablativnom dozom od 100 mCi, prosječna aktivnost po uspješnoj ablaciji je 2,6 puta manja s ablativnom dozom od 30 mCi J-131 nego s ablativnom dozom od 100 mCi J-131. U 79% ispitanika kod kojih je provedena uspješna ablacija s 100 mCi J-131 ista se uspješno mogla provesti i s manjom ablativnom dozom od 30 mCi J-131. Veću osjetljivost u detekciji ostatnog tkiva štitnjače ima scintigram s J-131 nego tireoglobulin (100% vs. 56%). Uspjeh ablacije mjeren negativizacijom tireoglobulina se ne razlikuje između ablativnih doza no nalaz tireoglobulina je upotrebljiv samo u 56% ispitanika.

GOAL OF STUDY: Investigation of radio-iodine ablation of the residual thyroid tissue after a total thyroidectomy with the ablation dose of 30 mCi J-131 in patients operated for well-differentiated carcinoma measuring up to 4 cm, without extra-thyroid infiltration and without metastases, and to compare the results with the ablation dose of 100 mCi J-131. HYPOTHESIS: The total activity of J-131 after the successfully conducted ablation is going to be smaller in patients who received an ablation dose of 30 mCi J-131 than in patients who were treated with ablation dose of 100 mCi J-131. In most patients who received a successful ablation dose of 100 mCi J-131 the same results could be received with a dose of 30 mCi J-131. Higher sensitivity level in detection of the residual thyroid tissue is seen with scintigram (J-131) than with thyroglobulin. SUBJECTS AND METHODS: I’ve conducted a retrospective observation research in the Clinical department for nuclear medicine, Clinical hospital centre Split, in the period from 2008.-2010., by investigating the medical documentation of 108 test subjects which have received an ablation dose of 30 mCi J- 131 and of 113 test subjects which were given the ablation dose of 100 mCi J-131. Second success parameter of the ablation in previously named groups of subjects was serum concentration of Tg before and after the successful ablation was conducted. RESULTS: Of 108 test subjects which received the ablation dose of 30 mCi J-131, successful ablation was observed in 85 (79%) of the subjects while in 113 who were given the ablation dose of 100 mCi J-131 showed success in 91 (89%) test subjects. The average activity of successful ablation in a group of subjects which were given the ablation dose of 30 mCi J-131 was 41 mCi, which is 2,6 times smaller than the average dose in the group of subject which were given the ablation dose of 100 mCi J-13, which was 107 mCi J-131. Higher sensitivity in detection of the residual thyroid tissue is seen in a scintigram with J-131 than with thyroglobulin (100% vs. 56%). In fact, Tg could have been used only in 125 patients because 45 of the test subjects had positive thyroglobulin antibodies and 51 subject,with negative Tg antibodies, had a negative Tg result at the time of the ablation. The success of the ablation was measured with the negative Tg results comparison which didn't differ in between the two ablation doses (79% in the group which was given the ablation dose of 30 mCi and 84% in the group which was given the ablation dose of 100 mCi) neither did the average reduction of Tg (0,8 vs. 0,7 ng/ml). Higher sensitivity in detection of the residual thyroid tissue was seen in a scintigram with J-131 than in thyroglobulin (100% vs. 56%). CONCLUSION: Although the success of ablation with the ablation dose of 30 mCi J-131 was 10% smaller than the success with the ablation dose of 100 mCi, the average activity of successful ablation was 2,6 times smaller with the ablation dose of 30 mCi J-131 than with the ablation dose of 100 mCi J-131. In 79% of test subjects which went through a successful ablation with a dose of 100 mCi J-131 the same efficiency could have been conducted with a smaller ablation dose of 30 mCi J-131. Higher sensitivity in detection of the residual thyroid tissue was seen in a scintigram with J-131 than in thyroglobulin (100% vs. 56%). The success of ablation measured by comparing the negative thyroglobulin results doesn’t differ in between the two ablation doses but the result can be only used in 56% of test subjects.