Use of gadolinium-based contrast agents in head and neck cancer diagnosis, staging, and monitoring: current applications and future perspectives.

Gadolinium-based contrast agents (GBCAs) have been fundamental to head and neck cancer (HNC) imaging, enabling effective detection, characterization, treatment response assessment, and disease progression monitoring of lesions. Additionally, perfusion-weighted imaging (PWI) utilizing dynamic contrast enhancement (DCE) has been evaluated for its ability to provide insights into microvascular parameters concerning blood flow within tumor tissue. Nevertheless, increasing worries regarding gadolinium accumulation within the central nervous system and its effects on the environment have led to a reconsideration of its application. This narrative review explores the current role of GBCAs in HNC imaging, the primary sequences used after GBCA administration, their interpretation, and potential alternative imaging approaches. Currently, GBCA administration is a cornerstone of multiparametric MRI for the diagnosis, staging, and monitoring of HNCs, commonly involving a 3D T1-weighted sequence with fat saturation during the equilibrium phase. While PWI shows potential for clinical application in HNCs, its broader clinical adoption requires further standardization. Notably, DCE can visually aid in detecting subtle tumors, and its application in the differential diagnosis of solid parotid lesions is yielding promising results. Arterial spin labeling is emerging as a compelling alternative for PWI, eliminating the need for GBCA administration. Other promising strategies for reducing or even avoiding GBCA use include hybrid PET/MRI examinations, the development of novel contrast agents (including high-relaxivity GBCAs and gadolinium-free contrast agents), and the implementation of artificial intelligence tools. KEY POINTS: Question When should GBCAs be administered to patients undergoing MRI for HNCs? Findings GBCA injection is a cornerstone of multiparametric MRI for the diagnosis, staging, and monitoring of HNCs. Clinical relevance GBCAs are recommended for HNC MRIs, with a possible exception for patients with no clinical or radiological evidence of recurrence after 27 months of follow-up. DCE is useful for identifying small carcinomas and characterizing parotid lesions.