International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2012
Pathologic validation of a model based on diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging for tumor delineation in the prostate peripheral zone.
For focal boost strategies in the prostate, the robustness of magnetic resonance imaging-based tumor delineations needs to be improved. To this end we developed a statistical model that predicts tumor presence on a voxel level (2.5×2.5×2.5 mm3) inside the peripheral zone. Furthermore, we show how this model can be used to derive a valuable input for radiotherapy treatment planning. ⋯ We developed a logistic regression with a high diagnostic performance for voxelwise prediction of tumor presence. The model output can be used to define different risk levels for tumor presence, which in turn could serve as an input for dose planning. In this way the robustness of tumor delineations for focal boost therapy can be greatly improved.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2012
Comparative StudyDosimetric study of current treatment options for radiotherapy in retinoblastoma.
To determine the best treatment technique for patients with retinoblastoma requiring radiotherapy to the whole eye. ⋯ Inverse planned image-guided radiotherapy delivered using HT or VMAT gives better conformity index, improved orbital bone and brain sparing, and a lower integral dose than other techniques.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2012
Multimodality local therapy for retroperitoneal sarcoma.
Soft-tissue sarcomas of the retroperitoneum are rare tumors comprising less than 1% of all malignancies. Although surgery continues as the mainstay of treatment, the large size of these tumors coupled with their proximity to critical structures make resection with wide margins difficult to achieve. The role and timing of radiotherapy are controversial. This study updates our institutional experience using multimodality local therapy for resectable retroperitoneal sarcoma and identifies prognostic factors impacting disease control and survival. ⋯ For retroperitoneal sarcoma, local control remains a challenge and combined-modality therapy may be associated with significant acute and late morbidity. Our patterns of failure data suggest that improvements in local control may translate into a survival benefit.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2012
Later outcomes and alpha/beta estimate from hypofractionated conformal three-dimensional radiotherapy versus standard fractionation for localized prostate cancer.
Now that the follow-up time has exceeded 5 years, an estimate of the α/β ratio can be presented. The additional late outcomes in patients treated with three-dimensional conformal external beam radiotherapy for localized prostate cancer using a hypofractionated vs. a standard fractionation regimen are reported from this prospective nonrandomized contemporary comparison. ⋯ The presented three-dimensional conformal regimen was acceptable, and the α/β value was 1.8, in agreement with other very recent low meta-analyses (reviewed in the "Discussion" section).
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2012
External-beam radiation therapy and high-dose rate brachytherapy combined with long-term androgen deprivation therapy in high and very high prostate cancer: preliminary data on clinical outcome.
To determine the feasibility of combined long-term androgen deprivation therapy (ADT) and dose escalation with high-dose-rate (HDR) brachytherapy. ⋯ Intermediate-term results at the 5-year time point indicate a favorable outcome without an increase in the rate of late complications.