Hypocalcemia Associated with Strontium-89 Administration in a Patient with Diffuse Bone Metastases from Neuroendocrine Carcinoma

Metastatic bone disease is often associated with severe pain in cancer patients, and has become an increasingly important quality-of-life issue. Radionuclides, such as strontium-89 (Sr-89), have provided effective palliation of metastatic bone pain. Although strontium follows the biochemical pathways of calcium in the body, changes in calcium homeostasis related to Sr-89 therapy have rarely been reported. We present a case of a 32-year-old male with poorly differentiated neuroendocrine carcinoma and extensive skeleton metastases who developed profound hypocalcemia after Sr-89 administration.