Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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Comparative Study Clinical Trial Controlled Clinical Trial
Internal organ motion in prostate cancer patients treated in prone and supine treatment position.
To compare supine and prone treatment positions for prostate cancer patients with respect to internal prostate motion and the required treatment planning margins. ⋯ For internal prostate movement, it is important to distinguish systematic from random variations. Compared to patients in supine position, patients in prone position had smaller random but somewhat larger systematic variations in the most important coordinates of the internal CTV position. The estimated planning margins to account for the geometrical uncertainties were therefore similar for the two treatment positions.
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Comparative Study
Conformal radiation therapy treatment planning reduces the dose to the optic structures for patients with tumors of the paranasal sinuses.
Compare dose distributions of traditional versus conformal beam orientations in paranasal sinus malignancies. ⋯ Conformal planning reduced the V80 to the optic nerves and chiasm as well as the normal tissue maximum doses to the ipsilateral and contralateral optic nerves and chiasm, and mean NTCPs.
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Randomized Controlled Trial Clinical Trial
Loco-regional recurrences after mastectomy in breast cancer: prognostic factors and implications for postoperative irradiation.
Potential risk factors including DNA flow cytometric-derived parameters predicting loco-regional recurrence (LRR) in early breast cancer were investigated. ⋯ Results indicate that T-stage and nodal status, combined with ECE, may help to identify patients at risk for loco-regional recurrence, whereas DNA flow cytometry does not.
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The integration of a scanner for computed tomography (CT) and a treatment simulator (Sim-CT, Elekta Oncology Systems, Crawley, UK) has been studied in a clinical situation. Image quality, hounsfield units (HU) and linearity have been evaluated as well as the implications for treatment planning. The additional dose to the patient has also been highlighted. ⋯ The CT-option can be considered as an added value to the simulation process and the images acquired on the Sim-CT system are adequate for dose calculation with tissue heterogeneity correction. The good image quality, however, is compromised by the relative high dose values to the patient. The considerable load to the conventional X-ray tube currently limits the Sim-CT to seven image acquisitions per patient and therefore the system is limited in its capability to perform full three-dimensional reconstruction.
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Comparative Study
Quantification and predictors of prostate position variability in 50 patients evaluated with multiple CT scans during conformal radiotherapy.
To determine the extent and predictors for prostatic motion in a large number of patients evaluated with multiple CT scans during radiotherapy, and evaluate the implications of these data on the design of appropriate treatment margins for patients receiving high-dose three-dimensional conformal radiotherapy. ⋯ Prostatic displacement during a course of radiotherapy is more pronounced among patients with initial planning scans with large rectal and bladder volumes. Such patients may require more generous margins around the CTV to assure its enclosure within the prescription dose region. Identification and correction of patients with large systematic errors will minimize the extent of the margin required and decrease the volume of normal tissue exposed to higher radiation doses.