International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Dec 2000
Intensity modulation to improve dose uniformity with tangential breast radiotherapy: initial clinical experience.
We present a new technique to improve dose uniformity and potentially reduce acute toxicity with tangential whole-breast radiotherapy (RT) using intensity-modulated radiation therapy (IMRT). The technique of multiple static multileaf collimator (sMLC) segments was used to facilitate IMRT. ⋯ The use of intensity modulation with an sMLC technique for tangential breast RT is an efficient and effective method for achieving uniform dose throughout the breast. It is dosimetrically superior to the treatment techniques that employ only wedges. Preliminary findings reveal minimal or no acute skin reactions for patients with various breast sizes.
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Int. J. Radiat. Oncol. Biol. Phys. · Dec 2000
Decreasing the dosimetric effects of misalignment when using a mono-isocentric technique for irradiation of head and neck cancer.
The purpose of this study was to quantify and develop methods to decrease inhomogeneities created with field edge mismatch when using a mono-isocentric beam-split technique. ⋯ The two methods of evaluating matchline dose described above gave similar results. When using the mono-isocentric half-field technique, small misalignments produce worrisome regions of inhomogeneity. Our penumbra generator substantially decreases the magnitude of the dose inhomogeneities, although the volume receiving an inhomogeneous dose increases.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2000
Adjuvant radiotherapy for margin-positive high-grade soft tissue sarcoma of the extremity.
Adjuvant radiotherapy (RT) has been shown to improve local control in patients with soft tissue sarcoma of the extremities (STS). The specific impact of adjuvant radiation on patients with positive margins, however, has not been clearly defined. The purpose of this study was to determine if adjuvant RT improves local control in patients with high-grade STS who had positive margins of resection. ⋯ Based on this study, adjuvant radiotherapy seems to improve local control in patients with high-grade STS of the extremity with positive margins. However, local recurrence still occurs in a substantial proportion of patients, mandating further need for improvement.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2000
Comparative StudyThe cost-effectiveness and cost-utility of high-dose palliative radiotherapy for advanced non-small-cell lung cancer.
To compute cost-effectiveness/cost-utility (CE/CU) ratios, from the treatment clinic and societal perspectives, for high-dose palliative radiotherapy treatment (RT) for advanced non-small-cell lung cancer (NSCLC) against best supportive care (BSC) as comparator, and thereby demonstrate a method for computing CE/CU ratios when randomized clinical trial (RCT) data cannot be generated. ⋯ The cost effectiveness and cost utility of high-dose palliative RT for advanced NSCLC compares favorably with the cost effectiveness of other forms of treatment for NSCLC, of treatments of other forms of cancer, and of many other commonly used medical interventions; and lies within the US $50, 000/QALY benchmark often cited for cost-effective care.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2000
Randomized Controlled Trial Clinical TrialIntraarterial (192)Ir high-dose-rate brachytherapy for prophylaxis of restenosis after femoropopliteal percutaneous transluminal angioplasty: the prospective randomized Vienna-2-trial radiotherapy parameters and risk factors analysis.
The aim of the Vienna-2-trial was to compare the restenosis rate of femoropopliteal arteries after percutaneous transluminal angioplasty (PTA) with or without intraarterial high-dose-rate (HDR) brachytherapy (BT) using an (192)Ir source. ⋯ BT after femoropopliteal PTA is feasible and a safe therapeutic option. No BT related morbidity was observed. A significant reduction of the restenosis rate was obtained in the PTA+BT arm. Subgroup analysis showed significant decrease of restenosis rate in the subgroups with restenosis after former PTA, occlusion and PTA length of greater than 10 cm. With dose escalation and reduction of dose variation by a centering device a further significant decrease of restenosis rate can be expected.