Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
A randomised trial of accelerated and conventional radiotherapy for stage III and IV squamous carcinoma of the head and neck: a Trans-Tasman Radiation Oncology Group Study.
The aims of this randomized controlled trial were to determine whether there were differences in the disease-free survival (DFS) and toxicity between conventional radiotherapy (CRT) and a continuous 3 week accelerated radiotherapy regimen (ART) in stage III and IV squamous cell carcinoma of the oral cavity, oropharynx, larynx and hypopharynx. ⋯ Differences in DFS, disease-specific survival and loco-regional control have not been demonstrated. ART resulted in more acute mucosal toxicity, but this did not result in greater prolongation of the treatment time compared with the CRT arm. There were less late effects in the ART arm, with the exception of late mucosal effects. This trial has confirmed that tumour cell repopulation occurs during conventionally fractionated radiotherapy for head and neck cancer. However, it has also provided additional evidence that overall improvements in the therapeutic ratio using accelerated fractionation strategies are seriously constrained by the need to limit total doses to levels that do not exceed acute mucosal tolerance. The accelerated schedule tested has been shown in this trial to be an acceptable alternative to conventionally fractionated irradiation to 70 Gy.
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Comparative Study
Radiotherapy-related early morbidity in head and neck cancer: quantitative clinical radiobiology as deduced from the CHART trial.
Early reactions after radiotherapy for head and neck cancer may become the limiting factor in current attempts to intensify loco-regional therapy through altered fractionation or combination of radiotherapy with chemotherapy. The aim of the present study was to quantify the dependence of early reactions on the dose-fractionation used in radiotherapy and on patients' age and radiation field size. ⋯ This study provides quantitative estimates of the dose-time and dose-volume relationships for human skin and normal mucosa in the head and neck region based on an analysis of data from 918 patients entered into a randomized-controlled trial of altered dose fractionation in radiotherapy.
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To define the influence of the dose and time on the response to treatment in postoperatively irradiated head and neck cancer patients and to establish a good prediction of failure. ⋯ Despite the absence of a statistically significant dose-response relationship, the present results suggest that postoperative irradiation treatment given to patients with head and neck squamous cell carcinomas should not be unduly prolonged, in order to minimize the amount of tumour cell proliferation. In these patients, nodal involvement, positive margins of the resected specimens and time interval between surgery and irradiation were the most important prognostic factors.
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We investigated the use of hypofractionated stereotactic radiotherapy (HFSR) to reduce adverse radiation effects in comparison to single-fraction stereotactic radiosurgery (SRS) for intracranial arteriovenous malformations (AVMs). ⋯ HFSR appears to be at least as effective as SRS in achieving complete obliteration of intracranial AVM, although its definitive role remains to be investigated.
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Comparative Study
Office hours pulsed brachytherapy boost in breast cancer.
Radiobiological studies suggest equivalent biological effects between continuous low dose rate brachytherapy (CLDR) and pulsed brachytherapy (PB) when pulses are applied without interruption every hour. However, radiation protection and institute-specific demands requested the design of a practical PB protocol substituting the CLDR boost in breast cancer patients. An office hours scheme was designed, considering the CLDR dose rate, the overall treatment time, pulse frequency and tissue repair characteristics. Radiobiological details are presented as well as the logistics and technical feasibility of the scheme after treatment of the first 100 patients. ⋯ An office hours PB boost regimen was designed for substitution of the CLDR boost in breast-conserving therapy on the basis of the BED. First treatment experience shows the office hour regimen to be convenient to the patients and no technical perturbations were encountered.