Strahlentherapie und Onkologie : Organ der Deutschen Röntgengesellschaft ... [et al]
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Clinical Trial
Concurrent Taxol and split-course accelerated radiotherapy for advanced head and neck cancer.
The aim of this study was to investigate feasibility and toxicity of fractionated paclitaxel administration concurrently with accelerated radiotherapy in the treatment of advanced head and neck cancer. ⋯ This regimen demonstrates a high activity in locally advanced head and neck cancer. Neutropenia associated with fever was the major dose limiting toxicity.
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Comparative Study
[Postoperative radiotherapy in the prevention of heterotopic ossification after endoprosthetic hip joint replacement].
Following total hip arthroplasty high-grade heterotopic ossification occurs with a range of 0.5 to 27%. Local postoperative hip irradiation using different dosage and fractionation schedules reduces the incidence in high-risk cases on an average of 8%. The present retrospective study compares results after conventionally fractionated and high-dose radiotherapy. ⋯ The data about the high therapeutic efficacy of postoperative radiotherapy for prevention of heterotopic ossification were confirmed. Both fractionation schedules led to a sufficient reduction of high-grade heterotopic ossification in the 2 treated risk groups.
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The pathogenesis of late delayed radiation damage in normal brain tissue is most likely due to damage to the vascular endothelium. The mitotic activity of gliomas was shown to correlate with the tumor induced angiogenesis. Dynamic susceptibility contrast MR imaging (DSC MRI) allows the measurement of the cerebral hemodynamics based on the indicator dilution theory. We describe theory and technique of the method and present our experience with blood volume measurements after irradiation of the CNS. ⋯ Radiation induced blood volume changes in the CNS can be measured using dynamic susceptibility contrast MR imaging. The measurements in normal brain tissue allow a functional in-vivo analysis of late delayed radiation reactions of the CNS. The definite value of intratumoral blood volume measurements for determination of the therapeutic success and for differentiation of recurrences versus radionecroses remains to be clarified in further studies.
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Comparative Study
[The dosage-performance effects on Ca-Ski and HPK cells in relation to the dose and fractionation].
The steep decrease of dose and dose-rate in brachytherapy implies very different radiobiological considerations of the biological effectivity. ⋯ Changing a LDR- into an HDR-brachytherapy the equivalent factors close to the source have to be selected low and with increasing distances from the source high respectively higher-the major problem for a mathematical formula. The reduction of the dose in HDR-radiation therapy is a compromise in order to limit side effects caused by a radiation. The trade-off is a small therapeutic range and reduced therapeutic effectivity at the tumor. The percutaneous dose at the pelvis wall has to be reduced if at the same time an HDR-brachytherapy will be carried out-to avoid side effects.