International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Oct 2005
Dose-volume based ranking of incident beam direction and its utility in facilitating IMRT beam placement.
Beam orientation optimization in intensity-modulated radiation therapy (IMRT) is computationally intensive, and various single beam ranking techniques have been proposed to reduce the search space. Up to this point, none of the existing ranking techniques considers the clinically important dose-volume effects of the involved structures, which may lead to clinically irrelevant angular ranking. The purpose of this work is to develop a clinically sensible angular ranking model with incorporation of dose-volume effects and to show its utility for IMRT beam placement. ⋯ The EUD-based function is a general approach for angular ranking and allows us to identify the potentially good and bad angles for clinically complicated cases. The ranking can be used either as a guidance to facilitate the manual beam placement or as prior information to speed up the computer search for the optimal beam configuration. Thus the proposed technique should have positive clinical impact in facilitating the IMRT planning process.
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Int. J. Radiat. Oncol. Biol. Phys. · Oct 2005
Results of spot-scanning proton radiation therapy for chordoma and chondrosarcoma of the skull base: the Paul Scherrer Institut experience.
To assess the clinical results of spot scanning proton beam radiation therapy (PT) in the treatment of skull base chordomas and low-grade chondrosarcomas (CS). ⋯ Spot-scanning PT offers high tumor control rates of skull base chordoma and CS. These results compare favorably to other combined proton-photon or carbon ion irradiation series. Observed toxicity was acceptable. Younger age (< or =40 years) was a favorable prognostic factor of PFS. These preliminary results are encouraging but should be confirmed during a longer follow-up.
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Int. J. Radiat. Oncol. Biol. Phys. · Oct 2005
Exclusive low-dose-rate brachytherapy in 279 patients with T2N0 mobile tongue carcinoma.
To evaluate the therapeutic results obtained with (192)Ir low-dose-rate interstitial brachytherapy in T2N0 mobile tongue carcinoma. ⋯ Exclusive low-dose-rate brachytherapy is an effective treatment for T2 tongue carcinoma. Regional control and survival are excellent in patients undergoing systematic neck dissection, which is mandatory in our experience because of a high rate of occult lymph node metastases.
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Int. J. Radiat. Oncol. Biol. Phys. · Oct 2005
Effectiveness of noncoplanar IMRT planning using a parallelized multiresolution beam angle optimization method for paranasal sinus carcinoma.
To determine the effectiveness of noncoplanar beam configurations and the benefit of plans using fewer but optimally placed beams designed by a parallelized multiple-resolution beam angle optimization (PMBAO) approach. ⋯ Parallelized multiple-resolution beam angle optimization with an optimized noncoplanar beam configuration is an effective and practical approach for IMRT treatment planning. Five-beam treatment plans optimized using the PMBAO are at least equivalent to, and overall better than, the plans using 9 equally spaced coplanar beams.
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
Adenoviral-E2F-1 radiosensitizes p53wild-type and p53null human prostate cancer cells.
E2F-1 is a transcription factor that enhances the radiosensitivity of various cell lines by inducing apoptosis. However, there are conflicting data concerning whether this enhancement is mediated via p53 dependent pathways. Additionally, the role of E2F-1 in the response of human prostate cancer to radiation has not been well characterized. In this study, we investigated the effect of Adenoviral-E2F-1 (Ad-E2F-1) on the radiosensitivity of p53wild-type (LNCaP) and p53null (PC3) prostate cancer cell lines. ⋯ Our results suggest that Ad-E2F-1 significantly enhances the response of p53wild-type and p53null prostate cancer cells to radiation therapy, although radiosensitization is more pronounced in the presence of p53. Ad-E2F-1 may be a useful adjunct to radiation therapy in the treatment of prostate cancer.