Background of the research:
Ewing Sarcoma affects about eighty patients in the UK each year. It is more common in adolescents at the time of peak growth. Treatment includes an intensive regime of chemotherapy and usually surgery, with or without radiotherapy. The surgery aims to remove the primary tumour safely and then reconstruct the bone to allow near-normal function.
Modern chemotherapy treatments are effective at shrinking the size of these tumours seen on MRI scans. Currently, where surgeons cut the bone (resection margin) is determined by MRI scans done before the start of chemotherapy and therefore unnecessarily large amounts of normal bone may be frequently removed alongside the tumour.
Using a different imaging protocol could result in less radical surgery, preserving more of the patient’’ bone and/or joints, meaning that their overall function and quality of life would be closer to normal.
The objective of this research project was to determine if using an MRI scan done after chemotherapy-which tends to be more representative of the actual tumour, as opposed to before chemotherapy, which includes the tumour plus surrounding bone build-up of fluid- to guide surgery, would still be safe and completely remove the tumour, while preserving more healthy bone and therefore, result in less aggressive surgery.
Results of the study:
The Oxford group completed a retrospective study on 20 patients, looking at their clinical, and surgical history, as well as analysing the available tissue samples for the presence of tumour versus healthy bone.
The researchers concluded that if they were to have based their surgical margins on post-chemotherapy MRI scans to preserve more healthy bone and/or joint, they would have cut through abnormal bone in roughly a third more cases. Therefore, they concluded that the current practice of determining tumour resection margins by MRI before chemotherapy is safe and they do not recommend the use of post- chemotherapy MRI to guide surgery.