Fetal outcome after technetium scintigraphy in early pregnancy

Physiological changes in pregnancy and their influence on the endocrine investigation

BACKGROUND

Physiological changes in pregnancy may result in significant alterations in endocrine hormone profiles, serum and urine electrolytes and endocrine gland morphology on imaging. Pregnancy-specific pathophysiological processes may also affect the results for endocrine tests. Investigation of endocrine disorders in pregnancy requires knowledge of these changes and awareness of the safety of dynamic hormone testing and imaging for the mother and foetus.

OBJECTIVE

This review seeks to outline the important physiological changes in pregnancy affecting reference intervals of basal and dynamic endocrine tests in pregnancy and the scenarios in which these changes are clinically significant, the pregnancy-specific disorders that may affect the investigation of endocrine disorders, and the safety of dynamic testing and imaging.

CONCLUSION

Awareness of the effect of physiological changes, and the potential impact of pregnancy-specific disorders of endocrine tests, and the safety of imaging is crucial to the management of endocrine disorders in pregnancy.

Detection of melanoma, breast cancer and head and neck squamous cell cancer sentinel lymph nodes by Tc-99m Tilmanocept (Lymphoseek®)

Technetium-99m-labeled Tilmanocept or Lymphoseek® (Cardinal Health, Dublin, Ohio) is a soluble, synthetic molecule with a small diameter (7 nm), which is comprised of technetium-99m chelated to a dextran backbone containing multiple units of mannose ligands with a high affinity for CD206, a receptor located on the surface of macrophages and dendritic cells that are found in high concentration in lymph nodes. It enables quick transit from the injection site and rapid lymph node accumulation. The binding of mannose ligand and CD206 results in the internalization of the ligand and receptor into the cell. Once the Technetium-99m-labeled Tilmanocept (Lymphoseek®) reaches the lymph node, it is readily internalized by the macrophages and dendritic cells within the draining lymph nodes. Technetium-99m-labeled Tilmanocept (Lymphoseek®) has been extensively studied as a radioisotope for detection of sentinel lymph nodes in melanoma, breast cancer and head and neck squamous cell carcinoma in clinical trials. Based on its safety and ability to detect sentinel lymph nodes satisfactorily, it has been approved by the FDA to use as a radioisotope for preoperative lymphoscintigraphy for identification of sentinel lymph nodes in these types of cancer. Further, the FDA has expanded approval of Technetium-99m-labeled for sentinel lymph node mapping of all solid tumors as well as in pediatric patients.

Hypercalcemia in Pregnancy

Hypercalcemic disorders are rare in pregnant women and are usually due to primary hyperparathyroidism. Clinical manifestations of hypercalcemia are nonspecific and can be masked by the physiologic changes of pregnancy. Furthermore, routine antenatal screening does not include serum calcium measurement and a hypercalcemia diagnosis may therefore be delayed until term or even after delivery. Timely recognition and appropriate interventions are essential to decrease maternal and fetal complications. Conservative measures are appropriate in the presence of mild hypercalcemia. Parathyroidectomy remains the mainstay of treatment for primary hyperparathyroidism with significant hypercalcemia not responding to conservative measures.

Hypercalcaemia during pregnancy: Review of maternal and fetal complications, investigations, and management

Introduction

Asymptomatic mild primary hyperparathyroidism is increasingly being identified during pregnancy. Recent studies have demonstrated inconsistent findings with regard to pregnancy complications and the need for surgical intervention during pregnancy.

Method

A retrospective audit of outcomes of pregnancies complicated by hypercalcaemia over a 15-year period was performed.

Results

Twenty-nine pregnancies to 26 women with hypercalcaemia were identified, corresponding to 37 cases per 100,000 deliveries. Hypercalcaemia was due to primary hyperparathyroidism in 90% of cases, with mean serum calcium of 2.89 mmol/l and mean ionised calcium 1.43 mmol/l. Four women underwent successful neck exploration during pregnancy. Pregnancy complications were limited to three cases of pre-eclampsia and one case of symptomatic neonatal hypoparathyroidism.

Conclusion

Close observation without surgical intervention would seem reasonable in women with mild hypercalcaemia during pregnancy.

Use of Cinacalcet and 99mTc-sestamibi Imaging During Pregnancy

A case report is reviewed, in which two nontraditional interventions were used in a patient with gestational primary hyperparathyroidism: cinacalcet and technetium-99m methoxyisobutylisonitrile imaging. The rationale for these decisions is considered in view of the available data.