Ga-DOTATATE PET in Restaging and Response to Therapy in Neuroblastoma: A Case Series and a Mini Review.

Ga-DOTATATE PET/CT is widely used for the evaluation of neuroendocrine tumors. Some reports exist on its use in the management of neuroblastoma. Building on the prior reports as well as our previous experience in using this technique for initial staging, we propose to describe its practical benefits in restaging and response to therapy. We describe different aspects including supply logistics, preparation, spatial resolution, and other practical applications. We reviewed the medical records for 8 patients who were evaluated with Ga-DOTATATE PET/CT at our institution over 2 y. A note was made of the patient and disease characteristics and the indication for PET imaging, and the results were retrospectively analyzed for feasibility, logistics, radiation exposure, and utility in answering the clinical question. Eight children (5 girls and 3 boys; age range, 4-60 mo; median age, 30 mo) diagnosed with neuroblastoma were imaged with Ga-DOTATATE PET/CT and 5 with I-metaiodobenzylguanidine (I-MIBG) SPECT/CT over 2 y. Three Ga-DOTATATE PET scans were done for staging, 10 for response evaluation, and 2 for restaging. Ga-DOTATATE PET accurately identified neuroblastoma lesions suspected or seen on anatomic imaging. It has been shown to be more specific and more sensitive than I-MIBG and at times also MRI. It had better spatial and contrast resolution than I-MIBG. Ga-DOTATATE PET was better than I-MIBG SPECT/CT, CT, and MRI in the detection of early progression and viable tumor delineation for response assessment, as well as in target volume definition for external-beam radiotherapy and proton-beam radiotherapy. Ga-DOTATATE PET was also better at assessing bony and bone marrow disease changes with time. Ga-DOTATATE PET/CT offers added value and a superior edge to other imaging modalities in restaging and response assessment in neuroblastoma patients. Further multicenter evaluations in larger cohorts are needed.