Evaluation of Resection Quality of Cerebral Metastases Using Fluorescence Guided Surgery: a Prospective Randomised Study

Overview

Few studies have evaluated the use of fluorescein sodium for the resection of brain tumours (especially glioblastomas) but also cerebral metastases. We therefore propose to evaluate the technique of fluorescence guided microsurgery (fluorescein sodium) compared to the conventional microsurgical technique in the resection of cerebral metastases in adults in order to specify, by a prospective and randomised study, the assistance provided by this technique in the quality of resection and the gain in terms of overall survival and local control of brain disease.

Cerebral metastases are a major public health problem in cancer patients. They are the most common brain tumours in adults. It is estimated that approximately 20-40% of patients with primary malignant neoplasia will develop cerebral metastasis during the course of their illness. In addition, the incidence of brain metastases is increasing due, in particular, to the aging of the population, as well as to the improvement of the overall management of cancer patients (cytotoxic or targeted systemic treatment) and easier access to magnetic resonance imaging (MRI), which improves patient survival. The prognosis of patients with brain metastases is still poor and the median overall survival of these patients is of the order of a few months. Although the management of brain metastases is multidisciplinary, the benefit of surgery has been clearly demonstrated in the literature. Consequently, it is demonstrated that the quality of the tumour excision and in particular the carrying out of the complete excision of contrast enhancement on the MRI is correlated with improved overall survival (especially in case of single metastasis) and improved local control of the disease or progression-free survival, but also a better quality of life. It is therefore essential to perform the most complete excision possible while minimising the associated morbidity. For this purpose, various tools for surgical resection have been developed and are available, including intraoperative fluorescence guided surgery. Sodium fluorescein is a fluorochrome that accumulates, after intravenous injection, into vascularised tumour tissues and is revealed intraoperatively by a light source of suitable wavelength (560 nm) using a set of lenses included in the microscope. The resection is thus guided by this fluorescence, the complete disappearance of which will translate into a complete tumour resection. Its interest is twofold: to increase the percentage of complete tumour resection and to improve survival without recurrence and overall survival.Few studies have evaluated the use of fluorescein sodium for the resection of brain tumours (especially glioblastomas) but also cerebral metastases. If two studies on brain metastases showed a complete resection rate greater than 80% and a better rate of local control of brain disease, it is important to note that these studies were not randomised (with a control arm), they did not really prove the effectiveness of this technique under fluorescence, hence the need to set up a randomised study. We therefore propose to evaluate the technique of fluorescence guided microsurgery (fluorescein sodium) compared to the conventional microsurgical technique in the resection of cerebral metastases in adults in order to specify, by a prospective and randomised study, the assistance provided by this technique in the quality of resection and the gain in terms of overall survival and local control of brain disease.