Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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Comparative Study
A prospective study on radiation pneumonitis following conformal radiation therapy in non-small-cell lung cancer: clinical and dosimetric factors analysis.
Clinical and dosimetric prognostic factors for radiation pneumonitis (RP) have been reported after three-dimensional conformal radiotherapy (3D-CRT) in patients with non-small cell lung cancer (NSCLC). ⋯ In this study, dosimetric factors (MLD, V20, V30) and age (> or =60 years) were predictive of RP regarding the whole pulmonary toxicity (grade > or =1). In addition, thresholds from 20 to 40 Gy, based on a stratification according to the median of the percentage of irradiated lung volume, were also predictive factors. They may, therefore, help discriminate patients at high and low risk for RP. However, only MLD, V20 and V30 remained associated with severe RP (grade > or =2), probably due to the small number of severe events in our series.
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Comparative Study
Dosimetric effect of respiratory motion in external beam radiotherapy of the lung.
To study the effect of breathing motion on gross tumor volume (GTV) coverage for lung tumors using dose-volume histograms and relevant dosimetric indices. ⋯ With the PTV margins routinely used at our center, the effects of normal breathing on coverage are small on the average, with a less than 4% chance of a 10% or greater decrease in D95, V95, or TCP. However, in patients with large respiration-induced motion, the effect can be significant and efforts to identify such patients are important.
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Comparative Study
Transforming growth factor-beta plasma dynamics and post-irradiation lung injury in lung cancer patients.
To investigate the relevance of transforming growth factor-beta (TGF-beta) dynamics in plasma for identification of patients at low risk for developing pneumonitis as a complication of thoracic radiotherapy (RT). ⋯ We observed a trend of plasma TGF-beta concentration to decrease below the pre-treatment value during the RT treatment in patients who did not develop pulmonary complications after the RT treatment. However, this trend was not consistent enough to warrant safe decision-making in clinical setting.
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Multicenter Study Comparative Study
Comparative study of permanent interstitial prostate brachytherapy post-implant evaluation among seven Italian institutes.
The purposes of this multicentric study are (a) the evaluation of four different commercially available treatment planning systems (TPSs) and (b) to verify whether the dosimetric results are comparable, also when considering the inter-observer variabilities and the different scanning protocols used. This work is to be considered a first step to test the value of multicentric studies based on dosimetric evaluation of the quality of the implants. ⋯ Three-dimensional (3D) geometric reconstructions of seed distributions are slightly dependent upon the operators and the scanning protocols have little effect on the dosimetric evaluation. Some relevant discrepancies were found between one of the TPSs and the other three if few sources were used; increasing the number of seeds those differences became less pronounced. Multicentric studies on the quality of prostate implants based on post-implant dosimetry are feasible, provided an accurate step-wise evaluation of the procedure be performed.
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To investigate the relation between acute toxicity and irradiated volume in the organs at risk during three-dimensional conformal radiation therapy for prostate cancer. ⋯ 3D-CRT radiation therapy to 70 Gy for prostate cancer was well tolerated. Only two of the 132 patients in the cohort experienced acute bladder toxicity Grade 3, none had Grade 3 rectal toxicity. Uni- and multivariate analyses indicated that the volume treated was a significant factor for the incidence of Grade 2 or higher acute morbidity.