Strahlentherapie und Onkologie : Organ der Deutschen Röntgengesellschaft ... [et al]
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Comparative Study
Radiobiological investigation of dose-rate effects in intensity-modulated radiation therapy.
Intensity-modulated radiation therapy (IMRT) has proven extraordinary capability in physical terms such as target conformity, dose escalation in the target volume, and sparing of neighboring organs at risk. The radiobiological consequences of the protracted dose delivery for cell survival and cell cycle progression are still unclear and shall be examined in this study. ⋯ Even at fraction times of 15-30 min the protracted dose delivery increases the survival rates in cell culture. The altered survival rates indicate the importance of the dose rate in the effectivity of IMRT. Besides physical parameters the consideration of biological factors might contribute to the optimization of IMRT in the future.
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. To evaluate late radiation effects in the brain after radiosurgery of patients with cerebral arteriovenous malformations (AVMs) and to quantify dose/volume-response relations for radiation-induced changes of brain tissue identified on follow-up neuroimaging. ⋯ . The derived dose/volume-response relations allow to quantitatively assess the risk of radiation-induced changes of brain tissue after radiosurgery in AVM patients. However, further understanding of the mechanism leading to brain tissue changes and their correlation with the desired obliteration is required. This knowledge will eventually help to optimize radiosurgical treatments in AVM patients.
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To examine the prognosis of breast cancer patients (T1-3, one to three positive axillary lymph nodes) and locoregional failure rate after breast-conserving therapy/modified radical mastectomy and adequate axillary dissection following tangential radiotherapy without irradiation of the regional lymph nodes. ⋯ Regional recurrence is uncommon among patients with one to three positive axillary lymph nodes treated with surgery, adequate axillary dissection, and tangential field irradiation only. The authors conclude that regional nodal irradiation should not routinely be given following adequate axillary dissection when only one to three lymph nodes are positive.
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Comparative Study
Postmastectomy radiotherapy of the chest wall. Comparison of electron-rotation technique and common tangential photon fields.
Different radiotherapy techniques are being used for postmastectomy irradiation. A retrospective analysis of patterns of locoregional failure (LRF) after modified radical mastectomy and axillary lymph node dissection followed by locoregional radiotherapy with or without systemic treatment was performed. Main emphasis was focused on the comparison of two postmastectomy radiotherapy techniques. ⋯ In locally advanced breast cancer, the LRC after postmastectomy irradiation with both techniques is comparable with published data from randomized studies. The tangential opposed photon field technique seems to be beneficial after marginal resection (histopathologic "close margins") of the primary tumor.
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Multicenter Study Clinical Trial
Accelerated partial breast irradiation with iridium-192 multicatheter PDR/HDR brachytherapy. Preliminary results of the German-Austrian multicenter trial.
To evaluate perioperative morbidity, toxicity, and cosmetic outcome in patients treated with interstitial brachytherapy to the tumor bed as the sole irradiation modality after breast-conserving surgery. ⋯ This analysis indicates that accelerated partial breast irradiation with iridium-192 interstitial multicatheter PDR/HDR implants is feasible with low perioperative morbidity, low acute and mild late toxicity, and does not significantly affect cosmetic results at a median follow-up of 24 months.