Iodine and Technetium Scintigraphy of the Thyroid

Huysmans, Dyde A.; Hermus, A.R.M.M.

doi:10.1007/978-1-4615-4341-1_6

“…Scintigraphy with iodine isotopes that are organified by the thyroid ( 131 I or 123 I) may have provided a better characterization of our cohorts of patients. Specifically, 99m Tc-pertechnetate is more available and less expensive than iodine isotopes, and 99m Tc-scintiscan is carried out faster than iodine scintigraphy (20 minutes vs 24 hours), which is a favorable feature in oncological patients [ 15 , 17 ]. Although measurement of technetium uptake might add useful data, the presence (Sci+) or absence (Sci–) of a thyroid image via 99m Tc-scintiscan were sufficient to identify those patients who were responsive to methimazole treatment in our cohort.…”

Section: Discussionmentioning

confidence: 99%

Management of Thyrotoxicosis Induced by PD1 or PD-L1 Blockade

Brancatella

¹

,

Lupi

²

,

Montanelli

³

et al. 2021

Journal of the Endocrine Society

View full text Add to dashboard Cite

Background Thyrotoxicosis is a common immune-related adverse event in patients treated with PD1 or PD-L1 blockade. A detailed endocrinological assessment, including thyroid ultrasound and scintigraphy is lacking, as are data on response to treatment and follow-up. Aim of this study was to better characterize the thyrotoxicosis secondary to immune checkpoint inhibitors, gaining insights into pathogenesis and treatment. Methods We conducted a retrospective study of 20 consecutive patients who had normal thyroid function before starting immunotherapy and then experienced thyrotoxicosis upon PD1 or PD-L1 blockade. Clinical assessment was combined with thyroid ultrasound, 99mTechnecium scintiscan and longitudinal thyroid function tests. Results Five patients had normal scintigraphic uptake (Sci+), no serum antibodies against the TSH receptor and remained hyperthyroid throughout follow-up. The other 15 patients had no scintigraphic uptake (Sci-) and experienced destructive thyrotoxicosis followed by hypothyroidism (N= 9) or euthyroidism (N= 6). Hypothyroidism was more readily seen in those with normal thyroid volume than in those with goiter (P= 0.04). Among Sci- subjects, a larger thyroid volume was associated to a longer time to remission (P<0.05). Methimazole (MMI) was effective only in Sci+ subjects (P<0.05). Conclusion Administration of PD1 or PD-L1 blocking antibodies may induce two different forms of thyrotoxicosis that appear similar in clinical severity at onset: a type 1 characterized by persistent hyperthyroidism that requires treatment with MMI and a type 2 characterized by destructive and transient thyrotoxicosis that evolves to hypo- or euthyroidism. Thyroid scintigraphy and ultrasound help differentiating and managing these two forms of iatrogenic thyrotoxicosis.

show abstract

“…Scintigraphy with iodine isotopes which are organified by the thyroid ( 131 I or 123 I), may have provided a better characterization of our cohorts of patients. Specifically, 99m Tc-pertechnetate is more available and less expensive than iodine isotopes and 99m Tc-scintiscan is carried out faster than iodine scintigraphy (20 minutes vs 24 hours), which is a favorable feature in oncological patients (15,17). Although measurement of technetium uptake might add useful data, the presence (Sci+) or absence (Sci-) of a thyroid image at 99m Tc-scintiscan were sufficient to identify those patients who were responsive to methimazole treatment in our cohort.…”

Section: Accepted Manuscript 10mentioning

confidence: 99%

Management of thyrotoxicosis induced by PD1 or PD-L1 blockade

Brancatella¹,

Lupi²,

Viola³

et al. 2021

EJEA

0

View full text Add to dashboard Cite

show abstract

“…Scintigraphy with iodine isotopes which are organified by the thyroid ( 131 I or 123 I), may have provided a better characterization of our cohorts of patients. Specifically, 99m Tc-pertechnetate is more available and less expensive than iodine isotopes and 99m Tc-scintiscan is carried out faster than iodine scintigraphy (20 minutes vs 24 hours), which is a favorable feature in oncological patients (15,17). Although measurement of technetium uptake might add useful data, the presence (Sci+) or absence (Sci-) of a thyroid image at 99m Tc-scintiscan were sufficient to identify those patients who were responsive to methimazole treatment in our cohort.…”

Section: Accepted Manuscript 10mentioning

confidence: 99%