Abstract
1367
Introduction: Hybrid imaging plays a major role in the modern nuclear medicine clinic. Applications are quite broad and may encompass endocrine indications. This is much more common in adults but also used effectively in the pediatric population. We propose to outline these uses in cases of ectopic thyroid tissue, primary and tertiary hyperparathyroidism. A 10 year old girl presented for evaluation by her pediatrician of an enlarging neck mass. This mass was initially noted at the age of 4 yo. Ultrasound assessment showed atrophy of the left lobe of the thyroid and isthmus with abnormal right lobe of thyroid and possible ectopic thyroid tissue at the base of the tongue. This prompted further evaluation with a Pertechnetate thyroid scan with SPECT-CT Figure 1. This demonstrated no functional thyroid tissue in the thyroid bed however demonstrated two clearly defined ectopic thyroidal masses. Total thyroidal uptake was also increased at 3.2%. This was followed with an MRI for preoperative planning Figure 1. On the other hand primary hyperparathyroidism is much less frequent in children than in adults. Nuclear medicine techniques can play a major role in clinical management. We present in Figure 2 the case of a 16 year old girl with incidental note of hypercalcemia found to have a high PTH of 27.3 pmol/L (Nl:1.3-7.5). Ultrasound was normal. Hybrid imaging with a SPECT-CT sestamibi scan was able to detect the exact location of an intrathymic parathyroid adenoma. This patient then underwent successful parathyroidectomy with gamma probe localization and intraoperative PTH measurement (PTH level dropped from 30 to 1.3).Additionally tertiary hyperparathyroidism occurs in end stage renal disease patients and can be treated with vitamin D and calcinet as in the case demonstrated in Figure 3. Surgery is ultimately needed with either subtotal parathyroidectomy versus total parathyroidectomy with autotransplatation of resected tissue. As in the case of a 10 yo boy on hemodialysis with a very high PTH at 90.5 pmol/L whom underwent subtotal parathyroidectomy with a parathyroid scan favoring the nodular type parathyroid hyperplasia and demonstrating that the largest PTH production was from the right side Figure 3.
Conclusions: Hybrid imaging nuclear medicine techniques are used successfully in pediatric endocrine disorders and when used appropriately can impact clinical management.