What is the optimal frequency and duration of post-operative radiological surveillance following resection of a solitary fibrous tumor?

Partly depends on the subset of SFT. The classic variant is low-grade, indolent clinical behavior and can recur late (several years later) requiring (maybe less frequent) but long-term follow-up for 10 years or even beyond. The malignant SFTs have a shorter natural history and typical sarcoma follow-up would be reasonable. The frank transformations to a sarcoma tend to behave very aggressively with relatively short intervals to recurrence.