Challenges and Pitfalls in MIBG Imaging: A Systematic Review.

内容摘要

Metaiodobenzylguanidine (MIBG) scintigraphy is an established imaging modality for evaluating neuroendocrine tumors, particularly pheochromocytoma and neuroblastoma; however, false-positive uptake remains a significant diagnostic challenge. This systematic review aimed to summarize reported pitfalls in MIBG scintigraphy, focusing on false-positive findings. PubMed and Scopus were searched for studies published between 1980 and November 2024 that reported false-positive MIBG uptake, including case reports, case series, and observational studies. Study selection followed predefined criteria, with additional articles identified through reference screening. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool for diagnostic accuracy studies and the CAse REport (CARE) checklist for case reports and case series. Ninety-one studies were included, comprising 170 documented false-positive cases. False-positive uptake most frequently involved the abdomen and pelvis (57.6%), followed by soft tissues and the skeletal system (31.8%), chest (7.1%), and head and neck regions (3.5%). Reported etiologies included non-tumoral conditions, benign and malignant tumors, and physiological or variant uptake patterns. The adrenal glands were the most common site of false-positive uptake, substantially complicating the diagnosis of pheochromocytoma. Awareness of these pitfalls, combined with careful clinical correlation, hybrid imaging, and complementary diagnostic modalities, is essential to improve diagnostic accuracy and reduce misinterpretation.