Subcutaneous Injection of 99mTc-Pertechnetate for Neonatal Thyroid Scintigraphy

Abstract

A 9-day-old female infant with congenital hypothyroidism presented for thyroid scintigraphy. Multiple attempts including the "intravenous team" failed to establish peripheral access for administration of 99mTc-pertechnetate. We administered 99mTc-pertechnetate subcutaneously into the upper arm. Rapid absorption (85% of the dose in 20 minutes) was documented on dynamic images with physiological uptake, allowing diagnostic thyroid scintigraphy at 35 minutes that revealed ectopic sublingual thyroid. Subcutaneous injection allowed us to avoid traumatic and risky central vascular access procedure. When peripheral intravenous access cannot be obtained, 99mTc-pertechnetate can be administered subcutaneously for diagnostic thyroid scintigraphy, which is particularly useful in neonates.

The Role of ¹²³I Imaging in the Evaluation of Infants with Mild Congenital Hypothyroidism

“…It can be completely performed within 30 min of 99m Tc administration and studies have suggested US, in conjunction with scintigraphy, can more accurately characterize the etiology of CH [16,17,18]. 99m Tc has the disadvantages of requiring intravenous or subcutaneous administration [19], and delivers a relatively high total body radiation dose of 50-250 µCi/kg body weight [20,21]. …”