International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
Longitudinal multivoxel MR spectroscopy study of pediatric diffuse brainstem gliomas treated with radiotherapy.
After radiotherapy (RT), children with diffuse intrinsic pontine gliomas (DIPG) are followed with sequential magnetic resonance imaging (MRI). However, MRI changes do not necessarily reflect tumor progression, and therefore additional noninvasive tools are needed to improve the definition of progression vs. treatment-related changes. In this study, we determined the feasibility and accuracy of multivoxel proton magnetic resonance spectroscopic imaging (1H-MRSI) for monitoring pediatric patients with DIPG. ⋯ Multivoxel MRSI is a feasible and reproducible noninvasive tool for assessing pediatric DIPG. Longitudinal multivoxel MRSI measurements have potential value in assessing response to radiation or other therapies, because they offer more coverage than single-voxel techniques and provide reliable spectral data.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
Where to locate the isocenter? The treatment strategy for repeat trigeminal neuralgia radiosurgery.
The purpose of this study is to investigate how the spatial relationship between the isocenters of the first and second radiosurgeries affects the overall outcome. ⋯ Image registration between MR scans of the first and second radiosurgeries helps target delineation and radiosurgery treatment planning. Increasing the isocenter distance between the two radiosurgeries treated a longer segment of the trigeminal neuralgia nerve and was associated with a trend toward improved pain relief.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
Intravaginal brachytherapy alone for intermediate-risk endometrial cancer.
Despite the results of the Gynecologic Oncology Group trial No. 99 (GOG#99), some unanswered questions still remain about the role of adjuvant radiotherapy (RT) for intermediate-risk endometrial cancer. First, can intravaginal brachytherapy (IVRT) alone substitute for external beam RT but without added morbidity? Second, is the high-risk (HR) definition from GOG#99 a useful tool to predict pelvic recurrence specifically? The purpose of this study was to try to answer these questions in a group of patients with Stage IB-IIB endometrial carcinoma treated with high-dose-rate (HDR) IVRT alone. ⋯ Tumor grade, depth of invasion, and the use of CSS were better predictors of pelvic control than the GOG#99 HR factors. IVRT alone seemed to provide adequate tumor control with very low morbidity. Therefore, it seems prudent to consider it for intermediate-risk patients because of its superior therapeutic ratio compared with that for surgery alone or pelvic RT. Additional follow-up, however, with a larger number of patients is needed, especially for those with LVI.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
An automatic CT-guided adaptive radiation therapy technique by online modification of multileaf collimator leaf positions for prostate cancer.
To propose and evaluate online adaptive radiation therapy (ART) using in-room computed tomography (CT) imaging that detects changes in the target position and shape of the prostate and seminal vesicles (SVs) and then automatically modifies the multileaf collimator (MLC) leaf pairs in a slice-by-slice fashion. ⋯ ART corrected for interfraction changes in the position and shape of the prostate and SVs and gave dose distributions that were considerably closer to the planned dose distributions than could be achieved with simple alignment strategies that neglect shape change. The ART proposed in this investigation requires neither contouring of the daily CT images nor extensive calculations; therefore, it may prove to be an effective and clinically practical solution to the problem of interfraction shape changes.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2005
Gamma knife radiosurgery of radiation-induced intracranial tumors: local control, outcomes, and complications.
To determine local control (LC) and complication rates for patients who underwent radiosurgery for radiation-induced intracranial tumors. ⋯ LC, survival, and complication rates in our series are comparable to those in previous reports of radiosurgery for intracranial meningiomas. Also, LC rates with radiosurgery are at least comparable to those of surgical series for radiation-induced meningiomas. Radiosurgery is a safe and effective treatment option for radiation-induced intracranial tumors, most of which are typical meningiomas.