thesis

Improving the outcomes for high-­risk neuroblastoma through the optimisation of radiotherapeutic techniques

Abstract

Neuroblastoma is a childhood cancer with highly variable clinical behaviour and outcomes. The long-­‐term survival rate for high-­‐risk neuroblastoma remains poor and new therapeutic advances and optimisation of existing therapies is therefore required. Both external beam radiotherapy and molecular radiotherapy have a significant role to play in the multi-­‐modality treatment of high-­‐risk disease. This collection of work examines ways in which the outcome for neuroblastoma may be improved through the introduction of new and enhancement of existing radiotherapeutic techniques. 131I-­‐meta-­‐Iodobenzylguanidine molecular radiotherapy has been used in the treatment of neuroblastoma since the mid 1980’s. Despite this, its role and efficacy remain undefined. A systematic review of 131I-­‐mIBG therapy in neuroblastoma is therefore presented. Radiolabelled somatostatin analogues target a distinct and separate molecular target on neuroblastoma cells to the noradrenaline transporter targeted by 131I-­‐mIBG. This study reports on the use of radiolabelled somatostatin analogues for the imaging and therapy of patients with high-­‐risk neuroblastoma. The expression of the two different molecular targets by immunohistochemistry for the noradrenaline transporter molecule and somatostatin receptor type-­‐2 in archived neuroblastoma tumour samples is also explored. The radiation doses received by comforters and carers providing necessary support to children undergoing molecular radiotherapy over a 10 year period is presented. The gold standard imaging modality for response assessment in neuroblastoma is 123I-­‐mIBG scinitgraphy. The role of other functional imaging techniques such as 18F-­‐ FDG PET/CT remains undefined. This study will look to see if 18F-­‐FDG PET/CT can give additional information with regards to response assessment. External beam radiotherapy is standardly delivered using conventional anterior and posterior parallel opposed beams and this can result in a compromise on target volume coverage to stay within the tolerance of normal tissues. The use of an Intensity Modulated Arc Therapy technique to improve target volume coverage is examined

    Similar works