CALCA and multiple endocrine neoplasia type 2A: Skoura et al. (17) also reported an interesting finding that the sensitivity of 18F-FDG PET/CT for medullary cancer recurrence in patients with multiple endocrine neoplasia (MEN) type 2A was significantly lower (23%), and for calcitonin levels <2000 pg/mL sensitivity was calculated as 0% in MEN 2A patients.