Nuclear Medicine Techniques in Paediatric Body Oncology: Present and Future

Modern nuclear medicine techniques combining anatomical and functional imaging have transformed our ability to diagnose, stage and prognosticate in paediatric oncology. Progress in the use of positron emission tomography (PET) in children with cancer has been relatively restrained compared to adults due to radiation concerns, limited research, availability, and the practical challenges associated with imaging young children. However, there have been several developments in the last decade and the role of molecular imaging in paediatric oncology will only broaden with forthcoming novel tracers and molecular radiotherapy. This review article summarises the practical aspects of nuclear imaging in paediatric oncology, discusses the main imaging methods including PET and single photon emission computed tomography (SPECT), appraises the available established and novel tracers, and summarises the evidence behind molecular imaging in paediatric lymphoma, neuroblastoma, sarcomas, thyroid cancer and other tumours. 18F-FDG PET/CT is the established method for staging and response assessment after induction chemotherapy in paediatric Hodgkin lymphoma and has high sensitivity for the detection of bone marrow disease, reducing the need for bone marrow biopsy in some cases. 123I-mIBG planar with SPECT imaging remains the mainstay for neuroblastoma imaging, however there is a well-established role for 18F-FDG PET/CT in mIBG non-avid disease, and 18F-DOPA and 68Ga-DOTA PET tracers have shown promising results as upcoming alternatives. 18F-FDG PET/CT is advocated in the staging assessment of rhabdomyosarcoma and has been shown to have excellent sensitivity in the detection of bone metastases in osteosarcoma and Ewing sarcoma, although standard chest CT is still recommended for the detection of lung metastases. The role of PET in germ cell tumours, hepatoblastoma, Wilms tumour and Langerhans cell histiocytosis is complementary to standard techniques.