An alternative analysis for crossover studies that accounts for between-group disparities in drug response

A 3-year-old girl presented with epigastric pain and physical examination showed a hard right upper quadrant mass. Urine VMA and HVA were found to be raised. CT scan showed a large mass arising from the right adrenal gland, with necrotic areas and ring calcification There was midline extension. The diagnosis of neuroblastoma was confirmed by bone marrow aspiration biopsy. As the patient had inoperable stage IV neuroblastoma, she was treated with multi-drug chemotherapy. Follow-up CT scan showed excellent response to the chemotherapy, and the tumour was successfully resected. Harvesting of autologous peripheral bone marrow stem cells, megatherapy with Melphalan, and marrow rescue with the stem cells were effective. The child has been well for three years to date. The clinical and imaging features of neuroblastoma, particularly the role of imaging in staging, are emphasised.