Introduction. Positron emission tomography/computer tomography (PET/CT) is one of the main imaging tests for solid tumor and metastases diagnostic nowadays. However, PET/CT scanning is related to the risk of ionizing radiation exposure, which is especially harmful for children health. Whole-body MRI (WB-MRI) allows exact evaluation of malignant tumor without the radiation exposure.
Aim of the Study.To compare and evaluate informativity of WB-MRI and PET/CT imaging methods for detection of metastases in children with malignant disease, being treated at Children’s Clinical University Hospital, Riga, Latvia. The gained data were also compared to the world data published before.
Material and methods. This retrospective study included all patients in whom both PET/CT and WB-MRI imaging examinations were performed between July 2016 and February 2017 in Latvia. Inclusion criteria were: age under 18 years, histological confirmation of a malignant disease. The study included 10 patients (7 males, 3 females, mean age 11 years 7 months). Two patients underwent both examinations 3 times, resulting in a total of 14 cases.
Results. There were identified three types of tumor: Hodgkin lymphoma (n = 12), non-Hodgkin lymphoma (n = 1), rhabdomyosarcoma (n = 1).
PET/CT mean radiation exposure was 263,2 [95% CI: 202.27 - 324.12] mGy.cm, mean radiotracer dosage was 143,5 [95% CI: 114. - 172.52] MBq.
There were identified 34 lesions: 24 (70%) lymph nodes, 5 (15%) bone lesions, 5 (15%) soft tissue lesions. 21 malignant lesions were detected by PET/CT. 27 lesions were found by WB-MRI. Out of 34 lesions, eighteen were identified by both imaging methods. Both examinations found absence of residual disease in 2 cases.
Eleven lesions were detected by WB-MRI (7 lymph nodes, 1 bone lesion and 3 soft tissue lesions) that were not identified by PET/ CT. 5 lesions could not be identified by WB-MRI (2 lymph nodes, 1 bone lesion and 2 soft tissue lesions) that were detected by PET/CT imaging method.
Conclusions. WB-MRI examination should be used before and in addition to PET/CT imagining in children with oncological disease. PET/CT examination results interpretation should be done based on WB-MRI imaging results. WB-MRI could not completely replace PET/CT imaging.
