Eur J Nucl Med 2001 Feb;28(2):203-8
Outcome after radioiodine therapy in 107 patients with differentiated thyroid
carcinoma and initial bone metastases: side-effects and influence of age.
Petrich T, Widjaja A, Musholt TJ, Hofmann M, Brunkhorst T, Ehrenheim C, Oetting
G, Knapp WH.
Initial bone metastases in patients with differentiated thyroid carcinoma are
rare, especially in younger patients. Long duration of therapy and high
activities of radioiodine are often necessary to induce remission of metastatic
disease. The curative potential of radioiodine therapy, in particular in younger
patients, has not yet been determined. In this retrospective study we evaluated
the therapeutic outcome, total radioiodine activities and associated
side-effects in 107 patients with initial bone metastases. Eight of the 107
patients were younger than 45 (37.5+/-7.3) years, and were classified as group 1
(stage II, "low risk", WHO classification). The remaining 99 patients
were older than 45 (64.1+/-9.5) years, and formed group 2 (stage IV, "high
risk", WHO classification). Total or partial remission was more frequently
achieved in group 1 than in group 2 (62.5% vs 49.5%). Lower activities were
needed in group 1 (18.89+/-15.08 GBq vs 41.97+/-31.25 GBq), and there were less
marked alterations in the blood count in this group. In group 1, blood count
alterations reached only grade I or II (WHO classification), whereas grade III
and grade IV alterations as well as acute leukaemia were observed in group 2. In
group 1, complete remission was achieved with radioiodine therapy (11.1 GBq) in
three out of four patients with < or =3 bone metastases. Additional pulmonary
metastases (present in 44 out of 107 patients) did not influence prognosis. We
conclude that initial bone metastases in differentiated thyroid carcinoma can be
treated with curative intent by means of radioiodine therapy, and that this
approach has a particularly realistic chance of success in younger patients and
those with a small number of metastases.
