International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2015
Impact of 1p/19q codeletion and histology on outcomes of anaplastic gliomas treated with radiation therapy and temozolomide.
Anaplastic gliomas represent a heterogeneous group of primary high-grade brain tumors, and the optimal postoperative treatment remains controversial. In this report, we present our institutional data on the clinical outcomes of radiation therapy (RT) plus temozolomide (RT + TMZ) for anaplastic gliomas, stratified by histology and 1p/19q codeletion. ⋯ RT + TMZ may be a promising treatment for both codeleted and non-codeleted AO/AOA, but its role for AA remains unclear.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2015
Six degrees-of-freedom prostate and lung tumor motion measurements using kilovoltage intrafraction monitoring.
Tumor positional uncertainty has been identified as a major issue that deteriorates the efficacy of radiation therapy. Tumor rotational movement, which is not well understood, can result in significant geometric and dosimetric inaccuracies. The objective of this study was to measure 6 degrees-of-freedom (6 DoF) prostate and lung tumor motion, focusing on the more novel rotation, using kilovoltage intrafraction monitoring (KIM). ⋯ The prostate and lung tumors were found to undergo rotations of more than 5° for about a third of the time. The lung tumor data represent the first 6 DoF tumor motion measured by kV images. The 6 DoF KIM method can enable rotational and translational adaptive radiation therapy and potentially reduce treatment margins.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2015
Comparative StudyComparison and limitations of DVH-based NTCP models derived from 3D-CRT and IMRT data for prediction of gastrointestinal toxicities in prostate cancer patients by using propensity score matched pair analysis.
This study compared normal tissue complication probability (NTCP) modeling of chronic gastrointestinal toxicities following prostate cancer treatment for 2 treatment modalities. Possible factors causing discrepancies in optimal NTCP model parameters between 3-dimensional conformal radiation therapy (3D-CRT) and intensity modulated RT (IMRT) were analyzed and discussed, including the impact of patient characteristics, image guidance, toxicity scoring bias, and NTCP model limitations. ⋯ Our analysis did not reveal a single definitive cause for discrepancies of model parameters between 3D-CRT and IMRT. Patient characteristics and bias in toxicity scoring, as well as image guidance alone, are unlikely causes of the large discrepancy of toxicities. Whether the cause was inherent to the specific NTCP models used in this study needs to be verified by future investigations. Because IMRT is increasingly used clinically, it is important that appropriate NTCP model parameters are determined for this treatment modality.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2015
Increasing radiation therapy dose is associated with improved survival in patients undergoing stereotactic body radiation therapy for stage I non-small-cell lung cancer.
To determine the comparative effectiveness of different stereotactic body radiation therapy (SBRT) dosing regimens for early-stage non-small-cell lung cancer, using a large national database, focusing on the relative impact of dose as a function of tumor stage. ⋯ This comparative effectiveness analysis of SBRT dose for patients with stage I non-small-cell lung cancer suggests that higher doses (>150 Gy BED) are associated with a significant survival benefit in patients with T2 tumors.