International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Hypofractionated intensity-modulated radiotherapy for carcinoma of the prostate: analysis of toxicity.
Dose escalation for prostate cancer improves biological control but with a significant increase in late toxicity. Recent estimates of low alpha/beta ratio for prostate cancer suggest that hypofractionation may result in biological advantage. Intensity-modulated radiotherapy (IMRT) should enable dose escalation to the prostate while reducing toxicity to local organs. We report late toxicity data of a hypofractionated IMRT regime. ⋯ These data demonstrate that hypofractionated radiotherapy using IMRT for prostate cancer is well tolerated with minimal late toxicity at 2 years posttreatment. Ongoing studies are looking at the efficacy of hypofractionated regimes with respect to biological control.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Magnetic resonance imaging-guided intracavitary brachytherapy for cancer of the cervix.
To determine the feasibility and benefits of optimized magnetic resonance imaging (MRI)-guided brachytherapy (BT) for cancer of the cervix. ⋯ MRI-based BT for cervical cancer has the potential to optimize primary tumor dosimetry and reduce the dose to critical normal tissues, particularly in patients with small tumors.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Optimal treatment planning for skull base chordoma: photons, protons, or a combination of both?
We compared dosimetry of proton (PR), intensity modulated radiation therapy (IMRT) photon (PH), and combined PR and IMRT PH (PP) irradiation of skull base chordomas to determine the most optimal technique. ⋯ There are dosimetric advantages to using either PH1 or PP plans, with the latter yielding the best target coverage and conformality.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Evaluation of image-guided positioning for frameless intracranial radiosurgery.
The standard for target alignment and immobilization in intracranial radiosurgery is frame-based alignment and rigid immobilization using a stereotactic head ring. Recent improvements in image-guidance systems have introduced the possibility of image-guided radiosurgery with nonrigid immobilization. We present data on the alignment accuracy and patient stability of a frameless image-guided system. ⋯ Frame-based and image-guided alignment accuracy in vitro was comparable for the system tested. In vivo tests showed a consistent trend in the difference of alignment in the anteroposterior direction, possibly due to torque to the ring and mounting system with frame-based localization. The mask system as used appeared adequate for patient immobilization.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2009
Multicenter StudyTime to treatment in patients with stage III non-small cell lung cancer.
To determine whether time to treatment (TTT) has an effect on overall survival (OS) in patients with unresectable or medically inoperable Stage III non-small cell lung cancer (NSCLC) and whether patient or treatment factors are associated with TTT. ⋯ Time to treatment is significantly associated with OS in patients with Stage III NSCLC who lived longer than 5 years, although it is not a significant factor in Stage III patients as a whole. Lower KPS is associated with longer TTT.