International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
Adenoviral-E2F-1 radiosensitizes p53wild-type and p53null human prostate cancer cells.
E2F-1 is a transcription factor that enhances the radiosensitivity of various cell lines by inducing apoptosis. However, there are conflicting data concerning whether this enhancement is mediated via p53 dependent pathways. Additionally, the role of E2F-1 in the response of human prostate cancer to radiation has not been well characterized. In this study, we investigated the effect of Adenoviral-E2F-1 (Ad-E2F-1) on the radiosensitivity of p53wild-type (LNCaP) and p53null (PC3) prostate cancer cell lines. ⋯ Our results suggest that Ad-E2F-1 significantly enhances the response of p53wild-type and p53null prostate cancer cells to radiation therapy, although radiosensitization is more pronounced in the presence of p53. Ad-E2F-1 may be a useful adjunct to radiation therapy in the treatment of prostate cancer.
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
The incidence and functional consequences of RT-associated cardiac perfusion defects.
Radiation therapy (RT) for left-sided breast cancer has been associated with cardiac dysfunction. We herein assess the temporal nature and volume dependence of RT-induced left ventricular perfusion defects and whether these perfusion defects are related to changes in cardiac wall motion or alterations in ejection fraction. ⋯ Radiation therapy causes volume-dependent perfusion defects in approximately 40% of patients within 2 years of RT. These perfusion defects are associated with corresponding wall-motion abnormalities. Additional study is necessary to better define the long-term functional consequences of RT-induced perfusion defects.
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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
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.