International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
ReviewThe American Society for Therapeutic Radiology and Oncology (ASTRO) evidence-based review of the role of radiosurgery for malignant glioma.
To systematically review the evidence for the use of stereotactic radiosurgery or stereotactic fractionated radiation therapy in adult patients with malignant glioma. ⋯ For patients with malignant glioma, there is Level I-III evidence that the use of radiosurgery boost followed by external beam radiotherapy and BCNU does not confer benefit in terms of overall survival, local brain control, or quality of life as compared with external beam radiotherapy and BCNU. The use of radiosurgery boost is associated with increased toxicity. For patients with malignant glioma, there is insufficient evidence regarding the benefits/harms of using radiosurgery at the time progression or recurrence. There is also insufficient evidence regarding the benefits/harms in the use of stereotactic fractionated radiation therapy for patients with newly diagnosed or progressive/recurrent malignant glioma.
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
Comparative StudyGlycerol rhizotomy versus gamma knife radiosurgery for the treatment of trigeminal neuralgia: an analysis of patients treated at one institution.
Medically refractory trigeminal neuralgia (TN) has been treated with a variety of minimally invasive techniques, all of which have been compared with microvascular decompression. For patients not considered good surgical candidates, percutaneous retrogasserian glycerol rhizotomy (GR) and gamma knife (GK) radiosurgery are two minimally invasive techniques in common practice worldwide and used routinely at Jefferson Hospital for Neuroscience. Using a common pain scale outcomes questionnaire, we sought to analyze efficacies and morbidities of both treatments. ⋯ Despite greater facial numbness morbidity and a higher failure rate, GR provided more immediate pain relief than GK. GR therefore should be considered in patients with disabling trigeminal pain requiring urgent pain relief. For all other patients, GK provides better long-term pain relief with less treatment-related morbidity, and should therefore be considered the preferred treatment for patients with medically refractory trigeminal neuralgia who are not suitable candidates for microvascular nerve decompression.
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
Clinical TrialPhase II dose escalation study of image-guided adaptive radiotherapy for prostate cancer: use of dose-volume constraints to achieve rectal isotoxicity.
In our Phase II prostate cancer Adaptive Radiation Therapy (ART) study, the highest possible dose was selected on the basis of normal tissue tolerance constraints. We analyzed rectal toxicity rates in different dose levels and treatment groups to determine whether equivalent toxicity rates were achieved as hypothesized when the protocol was started. ⋯ High doses (79.2 Gy) were safely delivered in selected patients by our adaptive radiotherapy process. Under the rectal dose-volume histogram constraints for the dose level selection, the risk of chronic rectal toxicity is similar among patients treated to different dose levels. Therefore, rectal chronic toxicity rates reflect the dose-volume cutoff used and are independent of the actual dose levels. On the other hand, a larger PTV will increase the rectal wall dose and chronic rectal toxicity rates. PTV volume and dose constraints should be defined, considering their potential benefit.
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
Esophagus sparing with IMRT in lung tumor irradiation: an EUD-based optimization technique.
The aim of this study was to evaluate (1) the use of generalized equivalent uniform dose (gEUD) to optimize dose escalation of lung tumors when the esophagus overlaps the planning target volume (PTV) and (2) the potential benefit of further dose escalation in only the part of the PTV that does not overlap the esophagus. ⋯ Intensity modulated radiation therapy optimizations that utilize gEUD-based cost functions for the PTV and NTCP-based constraints for the OARs result in increased doses to large portions of the PTV in cases where the PTV overlaps the esophagus, while still maintaining (and confining to the overlap region) minimum dose coverage equivalent to the homogeneous PTV optimization cases.