Stereotactic brachytherapy (SBT) has been described in several publications as an effective,minimal invasive and safe highly focal treatment option in selected patients with wellcircumscribed brain tumors <4 cm. However, a still ongoing discussion about indications andtechnique is hindering the definition of a clear legitimation of SBT in modern brain tumortreatment. These controversies encompass the question of how intense the irradiation shouldbe delivered into the target volume (dose rate). For instance, reports about the use of highdoes rate (HDR) implantation schemes ( >40 cGy/h) in combination with adjuvant externalbeam radiation and/or chemotherapy for the treatment of malignant gliomas and metastasesresulted in increased rates of radiation induced adverse tissue changes requiring surgicalintervention. Vice versa, such effects have been only minimally observed in numerous studiesapplying low dose rate (LDR) regiments (3-8 cGy/h) for low grade gliomas, metastases andother rare indications. Besides these observations, there are, however, no data availabledirectly comparing the long term incidences of tissue changes after HDR and LDR and thereis, furthermore, no evidence regarding a difference between temporary or permanent LDRimplantation schemes. Thus, recommendations for effective and safe implantation schemeshave to be investigated and compared in future studies.
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