Naslov
High ablation success rate achieved by the lowest I- 131 activity to date

Autori
Medvedec, Mario ; Dodig, Damir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstract Book of the 55th Annual Meeting of The Society of Nuclear Medicine (SNM) ; u: The Journal of Nuclear Medicine 49 (2008) (S1) / Schelbert, Heinrich R. - Reston (VA) : The Society of Nuclear Medicine, 2008, 8P-8P

Skup
Annual Meeting of The Society of Nuclear Medicine (25 ; 2008)

Mjesto i datum
New Orleans (LA), Sjedinjene Američke Države, 14.06.2008. - 18.06.2008

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
thyroid cancer; thyroid remnant ablation; radioiodine-131 activity

Sažetak
To investigate whether it is possible to achieve high success rate of thyroid remnant ablation by applying 900 MBq of I-131 in patients after thyroidectomy for differentiated thyroid cancer. The study included 220 patients who had [a] total thyroidectomy for papillary pT1-2N0M0 thyroid cancer, [b] TSH>30 mU/L, measured Tg and negative Tg antibodies while off T4 at ablation and in follow up, [c] treatment for thyroid remnant with 900 MBq of I-131, [d] post-ablation and follow up whole-body and neck/chest scintigraphy, [e] neck radioiodine uptake (RAIU) measurements in follow-up and [f] neck ultrasonography in follow-up. Ablation success rate was assessed by taking into account negative scintigraphy and RAIU<0.1% with 185 MBq of I-131, Tg<2 µg/L when off T4, and negative ultrasonography. The patents were given 900±15 MBq of I-131 at TSH of 88±39 mU/L. Post-ablation scans were positive in all (100%) patients, despite of skipped pre-ablation diagnostics with radioiodine. The first follow-up I-131 scans performed 9±2 months post-ablation were negative in 145/220 (66%) patients and in 316/414 (76%) initial lesions. During 41±17 months of follow-up I-131 scintigrams appeared finally negative in 175/220 (80%) patients and 350/414 lesions (85%) without any additional treatment. Simultaneously, Tg<2 µg/L, RAIU<0.1% and negative ultrasonographic scans appeared in 198/220 (90%), 205/220 (93%) and 208/220 (95%) patients, respectively. The lowest activity of I-131 (900 MBq/24 mCi) ever used in a large sample of post-surgical thyroid cancer patients appears justified, optimized and dose-compliant for clinically highly successful (~90%) but prolonged ablation of thyroid remnants, offering an exciting new perspective on radioiodine therapy for differentiated thyroid cancer.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Elektrotehnika, Kliničke medicinske znanosti

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