International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Evaluation of different score index for predicting prognosis in gamma knife radiosurgical treatment for brain metastasis.
To assess the utility of the Radiation Therapy Oncology Group Recursive Partitioning Analysis (RPA) and Score Index for Radiosurgery (SIR) stratification systems in predicting survival in patients with brain metastasis treated with Gamma Knife radiosurgery (GKRS). ⋯ This study supports the use of GKRS as a single-treatment modality in this selected group of patients. Stratification systems are useful in the estimation of patient eligibility for GKRS. A second-line treatment was necessary in 30% of patients to achieve distal or local brain control. This strategy is useful to control brain metastasis in long-surviving patients.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Stereotactic body radiotherapy is effective salvage therapy for patients with prior radiation of spinal metastases.
To provide actuarial outcomes and dosimetric data for spinal/paraspinal metastases, with and without prior radiation, treated with stereotactic body radiotherapy (SBRT). ⋯ Spine SBRT has shown preliminary efficacy and safety in patients with image-based progression of previously irradiated metastases.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Prognostic significance of 5-year PSA value for predicting prostate cancer recurrence after brachytherapy alone and combined with hormonal therapy and/or external beam radiotherapy.
To analyze the prognosis and outcomes of patients who remain free of biochemical failure during the first 5 years after treatment. ⋯ The results of this study have shown that the prognosis for patients treated with brachytherapy and who remain biochemically free of disease for >or=5 years is excellent and none developed metastatic disease during the first 10 years after treatment. The 5-year PSA value is prognostic, and patients with a PSA value <0.2 ng/mL are unlikely to develop subsequent biochemical relapse.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Integration of real-time internal electromagnetic position monitoring coupled with dynamic multileaf collimator tracking: an intensity-modulated radiation therapy feasibility study.
Continuous tumor position measurement coupled with a tumor tracking system would result in a highly accurate radiation therapy system. Previous internal position monitoring systems have been limited by fluoroscopic radiation dose and low delivery efficiency. We aimed to incorporate a continuous, electromagnetic, three-dimensional position tracking system (Calypso 4D Localization System) with a dynamic multileaf collimator (DMLC)-based dose delivery system. ⋯ Real-time target position information was successfully integrated into a DMLC effector system to modify dose delivery. Experimental results show both comparable dosimetric accuracy as well as improved efficiency compared with spatial gating.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2009
Frameless stereotactic body radiotherapy for lung cancer using four-dimensional cone beam CT guidance.
To quantify the localization accuracy and intrafraction stability of lung cancer patients treated with frameless, four-dimensional (4D) cone beam computed tomography (CBCT)-guided stereotactic body radiotherapy (SBRT) and to calculate and validate planning target volume (PTV) margins to account for the residual geometric uncertainties. ⋯ Frameless SBRT can be safely administered using 4D-CBCT guidance. Even with considerable breathing motion, the PTV margins can safely be kept small, allowing patients with larger tumors to benefit from the advantages of SBRT. In case bony anatomy would be used as a surrogate for tumor position, considerably larger PTV margins would be required.