Imaging in Cutaneous Melanoma: Current Workup, Surveillance, and Emerging Directions

Imaging techniques used for the care of cutaneous melanoma patients have greatly changed over the past century, from symptom-driven radiography toward a multimodality framework integrated for staging, directing surgery, and systemic therapy, and surveillance. Historically, clinical evaluation and skin exams have been the tenets of melanoma diagnosis and staging. In recent years, noninvasive imaging, such as dermoscopy, total-body photography and reflectance confocal microscopy, has expanded the diagnostic toolset for primary melanoma detection. Concurrently, several imaging techniques have been developed to detect metastases and follow disease progression, including computed tomography (CT), magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), lymphoscintigraphy, and single-photon emission computed tomography/computed tomography (SPECT/CT). The use of immune checkpoint inhibitors has also altered imaging interpretation by introducing atypical response patterns, including pseudoprogression, requiring immune-adapted assessment frameworks such as Immune Response Evaluation Criteria in Solid Tumors (iRECIST). While there is a strong consensus for high-risk patients, imaging techniques and surveillance schedules for low-risk patients (stage I/II) remain controversial due to limited supporting evidence and conflicting data on costs and patient benefit. The development of new technologies, including image-guided surgery, non-FDG PET tracers, phone apps, artificial intelligence-assisted image analysis, and radiomics, may further change melanoma imaging. The aim of this review is to detail the historical evolution of melanoma imaging, the development of new imaging techniques, and their role and future in clinical practice.