International journal of radiation oncology, biology, physics
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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
Influence of site on the therapeutic ratio of adjuvant radiotherapy in soft-tissue sarcoma of the extremity.
The ultimate goal of adjuvant radiotherapy (RT) in soft-tissue sarcoma of the extremity is to improve the therapeutic ratio by increasing local control while minimizing morbidity. Most efforts in trying to improve this ratio have focused on the sequencing of RT and surgery, with little attention to the potential influence of the tumor site. The purpose of this study was to determine the influence of tumor site on local control and complications in a group of patients with primary high-grade soft-tissue sarcoma of the extremity treated at a single institution with postoperative RT. ⋯ The UE site is associated with a greater rate of local recurrence compared with the LE. This difference was independent of other variables and could not be accounted for by an imbalance between the two groups. With a lower wound complication rate associated with an UE site, it would be of interest to determine whether preoperative RT and/or intensity-modulated RT can increase the local control in UE sarcomas, thus improving the therapeutic ratio.
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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 brain metastases.
To systematically review the evidence for the use of stereotactic radiosurgery in adult patients with brain metastases. ⋯ Based on Level I-III evidence, for selected patients with small (up to 4 cm) brain metastases (up to three in number and four in one randomized trial), the addition of radiosurgery boost to whole-brain radiotherapy improves brain control as compared with whole-brain radiotherapy alone. In patients with a single brain metastasis, radiosurgery boost with whole-brain radiotherapy improves survival. There is a small risk of toxicity associated with radiosurgery boost as compared with whole-brain radiotherapy alone. In selected patients treated with radiosurgery alone for newly diagnosed brain metastases, overall survival is not altered. However, local and distant brain control is significantly poorer with omission of upfront whole-brain radiotherapy (Level I-III evidence). Whether neurocognition or quality of life outcomes are different between initial radiosurgery alone vs. whole-brain radiotherapy (with or without radiosurgery boost) is unknown, because this has not been adequately tested. There was no statistically significant difference in overall toxicity between those treated with radiosurgery alone vs. whole-brain radiotherapy and radiosurgery boost based on an interim report from one randomized study. There is insufficient evidence as to the clinical benefit/risks radiosurgery used in the setting of recurrent or progressive brain metastases, although radiographic responses are well-documented.
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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.