Because of the catecholamine-secreting nature of these tumors, pheochromocytomas and paragangliomas (PPGLs) can manifest in various serious symptoms and signs that often go undiagnosed or misdiagnosed. More than 100 symptoms and signs have been described in association with these tumors, including but not limited to hypertension, headaches, hyperglycemia, palpitations, nausea, pain, vomiting, anxiety, and diaphoresis. Because of the delay in diagnosis, patients often present with large tumors and/or distant metastases, and patients endure significant burdens resulting from hormonal dysfunction and tumor progression. Furthermore, the treatment of PPGL can be challenging. Fortunately, an improved understanding of PPGL is leading to better diagnostic evaluation, more appropriate patient-specific treatment strategies, and improved patient outcomes. The recently US Food and Drug Administration (FDA)-approved iobenguane iodine-131 (I-131) may have high specific activity (HSA) and little to no unlabeled meta-iodobenzylguanidine (MIBG), potentially providing an advantage over conventional I-131 MIBG in the PPGL setting.
This activity will inform clinicians who treat patients with PPGL of the therapeutic potential of the newest HSA I-131 MIBG, which was added to the treatment armamentarium less than 1 year ago.