Registry series: (Penn Cincinnati series) Glioblastoma (2003)

- Most recent risk assessment for low-grade gliomas (astrocytoma, oligodendroglioma, ependymoma) (WHO grades 1-2) Council of Europe, 2025): Potential donors with WHO grade 1 and 2 gliomas may be considered for organ donation with minimal risk of transmission. Extraneural metastases from WHO grade 1 and 2 gliomas are rare, and have been associated with resection and ventriculo-peritoneal shunts. In the absence of these risk factors, the donor may be considered minimal-risk. Risk may increase with the extent of performed interventions. A complete histological examination of the tumour should be performed so that areas of transformation into a more aggressive malignancy can be ruled out. Since WHO grade 2 astrocytoma IDH-mutant has a tendency to relapse with a histologically higher grade of malignancy, new histological examinations to regrade the tumour should be performed where relapse occurs. If the tumour co-exists with histological areas of greater malignancy or is very invasive locally, it should be considered high-grade and will be associated with an increased risk of transmission. - Most recent risk assessment for astrocytoma WHO grades 3 or 4 and glioblastoma WHO grade 4 (Council of Europe, 2025): Spontaneous extraneural metastases of grade 3 astrocytomas and grade 4 glioblastomas are rare, but such metastases have been observed, and seem to occur more frequently when associated with prior surgical treatment and/or ventriculo-peritoneal drainage or chemo-/radiotherapy. Potential donors with WHO grade 3 astrocytomas can be accepted as organ donors. Transmission risk is considered low to intermediate for tumours without any risk factors. Potential donors with glioblastoma IDH-wildtype or astrocytoma IDH-mutant are considered intermediate risk for transmission, depending on different national recommendations, which are expected to be adjusted with increasing evidence. The transmission risk is increased in all cases with previous interventions such as tumour resection, ventriculo-peritoneal/-atrial drainage and/or cranial chemo-/radiotherapy.