International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
The role of whole brain radiotherapy and stereotactic radiosurgery on brain metastases from renal cell carcinoma.
We reviewed our experience with patients who have undergone stereotactic radiosurgery (SRS) for brain metastases secondary to renal cell carcinoma (RCC). Analysis was performed to determine the survival, local control, distant brain failure (DBF), and then to define which tumors may not require upfront whole-brain radiotherapy (WBRT). ⋯ Patients with brain metastases secondary to RCC treated by SRS alone have excellent local control. The decision of whether or not to add WBRT to SRS should depend on whether the patient has a high likelihood of developing DBF. Our study suggests that patients who present with multiple brain lesions may be more likely to benefit from the addition of WBRT because they appear to be more than twice as likely to develop DBF as compared to patients with a single lesion.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
Modeling normal tissue complication probability from repetitive computed tomography scans during fractionated high-dose-rate brachytherapy and external beam radiotherapy of the uterine cervix.
To calculate the normal tissue complication probability (NTCP) of late radiation effects on the rectum and bladder from repetitive CT scans during fractionated high-dose-rate brachytherapy (HDRB) and external beam radiotherapy (EBRT) of the uterine cervix and compare the NTCP with the clinical frequency of late effects. ⋯ The NTCP for the rectum was almost consistent with the clinical frequency of late effects, whereas the NTCP for bladder was too high. To obtain reliable (SD of 12-13%) NTCP values, 3-4 CT scans are needed during 5-7 fractions of HDRB treatments.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
The prediction of late rectal complications following the treatment of uterine cervical cancer by high-dose-rate brachytherapy.
This study aimed to correlate patient, treatment, and dosimetric factors with the risk of late rectal sequelae in patients with uterine cervical cancer treated with external beam radiation therapy (EBRT) and high dose rate intracavitary brachytherapy (HDRICB). ⋯ Risk factors of late rectal complications were advanced stage, age greater than 70 years, and cumulative rectal dose of greater than 65 Gy.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
Application of recursive partitioning analysis and evaluation of the use of whole brain radiation among patients treated with stereotactic radiosurgery for newly diagnosed brain metastases.
To evaluate the usefulness of whole brain radiotherapy (WBRT) and of the Radiation Therapy Oncology Group recursive partitioning analysis (RPA) for brain metastases among patients receiving stereotactic radiosurgery (SRS). ⋯ Despite the inherent biases to select more favorable patients for SRS, the RPA class retains its prognostic value. Omission of WBRT from the initial management was not detrimental in terms of overall survival; however, progressive disease occurred in over 50% of patients treated in this manner. Further studies are required to determine which, if any, patients should be considered for SRS with WBRT held in reserve.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
Dose-dependent induction of transforming growth factor beta (TGF-beta) in the lung tissue of fibrosis-prone mice after thoracic irradiation.
The lung is the major dose-limiting organ for radiotherapy of cancer in the thoracic region. The pathogenesis of radiation-induced lung injury at the molecular level is still unclear. Immediate cellular damage after irradiation is supposed to result in cytokine-mediated multicellular interactions with induction and progression of fibrotic tissue reactions. The purpose of this investigation was to evaluate the acute and long-term effects of radiation on the gene expression of transforming growth factor beta (TGF-beta) in a model of lung injury using fibrosis-sensitive C57BL/6 mice. ⋯ This study demonstrates an acute and long-lasting increase in the expression of TGF-beta in lung tissue following thoracic irradiation with 12 Gy. The predominant localization of TGF-beta in areas of inflammatory cell infiltrates and fibrosis suggests involvement of this cytokine in the pathogenesis of radiation-induced pulmonal fibrosis. Further studies should be performed to explore the role of other cytokines in the development of radiation injury. An improved understanding of the underlying mechanisms of pulmonary fibrosis may eventually lead to modulatory intervention at the molecular level to modify the fibrotic process.