m-Iodobenzylguanidine hemisulfate salt is primarily used in nuclear medicine for diagnostic imaging. It is particularly valuable in the detection and localization of neuroendocrine tumors, such as pheochromocytoma, neuroblastoma, and paraganglioma. The compound acts as a radiopharmaceutical agent, where it is labeled with radioactive iodine (I-123 or I-131) to enable imaging through techniques like single-photon emission computed tomography (SPECT). Its ability to accumulate in adrenergic tissue makes it highly effective for identifying these types of tumors. Additionally, it is utilized in therapeutic applications for certain neuroendocrine cancers, where the radioactive component helps target and destroy malignant cells. Its specificity and efficacy have made it a critical tool in oncology and diagnostic radiology.