title: Advances in treatment techniques and time/dose schedules in external radiation therapy of brain tumours in childhood.
abstract: Recent advances in radiotherapy techniques seek to improve the therapeutic ratio in childhood brain tumours by adding potentially more effective treatment in ways that will increase tumour control and limit radiation toxicity. Stereotactic irradiation techniques in conjunction with rigid head fixation systems comprising single high-dose delivery ("radiosurgery"), fractionated convergence therapy and three dimensional conformal therapy focus the dose to tumour while sparing surrounding normal tissue. Although these techniques are well established in adults data for childhood central nervous system malignancies are scarce. Preliminary data reveal low acute toxicity and promising results in recurrent tumours as well as in primary treatment. Whether stereotactic radiation therapy with either of the latter techniques will add substantially to disease control and preserve neurologic function remains to be established and should be part of future investigations. The introduction of quality control procedures assures precise radiotherapy of the tumour site, whole brain and craniospinal axis and is a prerequisite to improve survival and to reduce potential adverse effects. Hyperfractionated radiotherapy has the potential of increasing dose to tumour more safely theoretically sparing children some of the late effects while in particular in craniospinal irradiation. Pilot studies revealed excellent tumour control in medulloblastoma with acceptable acute toxicity. The strategy is part of the subsequent HIT '98 trial both for low and high risk patients. In conclusion, there is considerable enthusiasm among all those caring for children with brain tumours to study modifications of radiation delivery that may result in improved treatment. Rapid accrual to an increasing number of cooperative prospective trials is expected to provide the body of data supporting the selection of novel radiation therapy modalities in the future.
authors.affiliation: Department of Radiotherapy, University of Tuebingen.
authors.forename: R D
authors.initials: RD
authors.lastname: Kortmann
authors.forename: B
authors.initials: B
authors.lastname: Timmermann
authors.forename: G
authors.initials: G
authors.lastname: Becker
authors.forename: J
authors.initials: J
authors.lastname: Kühl
authors.forename: M
authors.initials: M
authors.lastname: Bamberg
mesh_terms: D000328:Adult; D001918:Brachytherapy / Q000295:instrumentation; D001932:Brain Neoplasms / Q000532:radiotherapy*; D002528:Cerebellar Neoplasms / Q000532:radiotherapy; D002648:Child; D003131:Combined Modality Therapy; D016371:Cranial Irradiation / Q000295:instrumentation; D019583:Dose Fractionation, Radiation; D006801:Humans; D008527:Medulloblastoma / Q000532:radiotherapy; D016634:Radiosurgery / Q000295:instrumentation; D016896:Treatment Outcome