Application of ⁹⁹Tc^m-MDP SPECT/CT imaging in Langerhans cell histiocytosis in children

Objective: To explore the clinical value of ⁹⁹Tc^m-methylene diphosphonate (MDP) SPECT/CT imaging in Langerhans cell histiocytosis (LCH) in children. Methods: From June 2018 to October 2019, the imaging characteristics of ⁹⁹Tc^m-MDP SPECT/CT imaging in 13 children (8 males, 5 females; age: 1-11 (4.2 ± 2.8) years) with LCH confirmed by pathology and immunohistochemistry in Wuhan Children's Hospital were analyzed retrospectively. The location, number, imaging manifestations, and maximum standardized uptake value (SUV_max) of the lesions were evaluated. Results: There were 18 lesions (8 in the vertebral body, 3 in the femur, 3 in the skull, 2 in the rib, 1 in the shoulder blade, 1 in the sciatic and pubic bone) in 13 children, including 9 with single lesion and 4 with multiple lesions. Of 18 lesions, 17 showed different degrees of osteolytic bone destruction, 15 presented as soft tissue masses, and 3 showed marginal sclerosis on CT imaging. All lesions showed increased ⁹⁹Tc^m -MDP uptake (SUV_max: 1.22-15.57 (8.67 ± 3.19)). Conclusion: ⁹⁹Tc^m-MDP SPECT/CT has the advantage of combining functional and morphological imaging, and is helpful in the early diagnosis, clinical classification and evaluation of curative effect of children's LCH, which provides objective basis for clinical practice. (authors)