[First results of radioiodine therapy of multifocal and disseminated thyroid gland autonomy and use of a TcTUs-adapted dose concept].
OBJECTIVE
The presented study examines prospectively the efficiency of a dose concept for radioiodine therapy (RIT) adapted to the pretherapeutic 99mTc-pertechnetate thyroid uptake under suppression (TcTUs) in patients with multifocal (MFA) and disseminated (DISA) autonomy. This concept considers the total thyroid as target volume and uses target doses from 150 Gy to 300 Gy according to the TcTUs, which is as a measure for the "autonomous volume" of the thyroid.


METHODS
The data of 75 patients (54 female, 21 male; age 71 +/- 9 years) with MFA of DISA were evaluated. RIT was performed on patients presenting with normal values for free triiodothyronine and thyroxine and endogenous suppression of the basal thyrotropin (TSH). The following target dose were used for a TcTUs of 1.5-2.5% 150 Gy, for 2.51-3.5% 200 Gy, for 3.51-4.5% 250 Gy, and for > 4.5% 300 Gy. The radiation dose to be administered was calculated using a modified Marinelli formula. The therapy was considered as successful. When the basal TSH was above 0.5 mU/l and autonomous areas had disappeared in thyroid scintigraphy or the TcTU was below 1.5%, respectively. The average follow-up period was 8 +/- 4 months.


RESULTS
The success rates average to 92%. Only in one case a subsequent subclinical hypothyroidism and in a further case an immunogenic hyperthyroidism occurred.


CONCLUSIONS
The presented data indicate that even patients with a marked autonomy (TcTUs > 3.5%) can thus expected to be cured by of a one time therapy with success rate of over 90% using the presented dose concept. The rate of early hypothyroidism can altogether be estimated as very low.
Abteilung Nuklearmedizin, Klinikum der Albert-Ludwigs Universität, Freiburg i. Br., Deutschland.
C
C
Oexle
M
M
Reinhardt
E
E
Moser
D000368:Aged; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D011446:Prospective Studies; D011859:Radiography; D011877:Radionuclide Imaging; D011879:Radiotherapy Dosage; D013670:Sodium Pertechnetate Tc 99m / Q000493:pharmacokinetics; D013961:Thyroid Gland / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D013972:Thyrotropin / Q000378:metabolism; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D007457:Iodine Radioisotopes; D014284:Triiodothyronine; D013972:Thyrotropin; D013670:Sodium Pertechnetate Tc 99m; D013974:Thyroxine
Erste Ergebnisse der Radioiodtherapie bei multifokaler und disseminierter Autonomie der Schilddrüse unter Verwendung eines TcTUs-adaptierten Dosiskonzepts.