Posttreatment Imaging Surveillance

Posttreatment imaging surveillance in patients treated for anterior skull base tumors is a multifaceted issue which - as a first step - requires tailoring of the selection of imaging technique and acquisition protocol to the clinical scenario. As a general rule, acute symptoms suggesting the onset of a complication of treatment require prompt diagnosis through an easily accessible technique, such as CT; on the other hand, monitoring recurrences in asymptomatic patients is best achieved with MRI, exploiting the inherently higher contrast resolution. The interpretation of follow-up imaging studies is challenging. First of all, it is essential to be aware of specific characteristics of the natural history that may differ significantly between histologies, influencing the pattern and timing of recurrences. Additionally, resection of the lesion and reconstruction of the defect (as well as radiation treatment) produce complex anatomical changes, which may mislead inexperienced radiologists; this concept emphasizes the centrality of collecting accurate information on treatment modalities and procedures applied before scanning in each patient. This enables the pattern of expected posttreatment changes to be anticipated and, consequently, recurrences or complications to be more easily identified.