TY - JOUR T1 - Hexokinase-2 Expression in <sup>11</sup>C-Methionine–Positive, <sup>18</sup>F-FDG–Negative Multiple Myeloma JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 348 LP - 352 DO - 10.2967/jnumed.118.217539 VL - 60 IS - 3 AU - Stefan Kircher AU - Antje Stolzenburg AU - Klaus Martin Kortüm AU - Malte Kircher AU - Matteo Da Via AU - Samuel Samnick AU - Andreas K. Buck AU - Hermann Einsele AU - Andreas Rosenwald AU - Constantin Lapa Y1 - 2019/03/01 UR - http://jnm.snmjournals.org/content/60/3/348.abstract N2 - PET with 18F-FDG is the standard modality in nuclear medicine for imaging multiple myeloma (MM). However, viable MM as detected by MRI or PET with other metabolic tracers, including 11C-methionine, may be missed—for example, because of low hexokinase 2 (HK2) expression of tumor cells. The aim of this study was to further investigate potential reasons for PET false negativity. Methods: A cohort of 15 mainly pretreated patients with relapsed or refractory biopsy-proven, serologically active MM who underwent both 18F-FDG and 11C-methionine PET/CT was retrospectively analyzed. Results: In 9 of the 15 patients, 18F-FDG PET was negative in the presence of viable disease. In the remaining 6 patients, both 18F-FDG and 11C-methionine PET/CT revealed the same number of MM lesions. At immunohistochemistry, 18F-FDG–negative myeloma did not exhibit significant differences in HK2 or glucose-6-phosphatase expression from 18F-FDG–positive disease (P = 0.57 and P = 0.44, respectively). Conclusion: Beyond HK2 expression, 18F-FDG negativity in (mainly pretreated) MM patients seems to be associated with additional causes not yet known. ER -