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
Concurrent hyperfractionated radiation therapy and chemotherapy in locally advanced (Stage III) non-small-cell lung cancer: single institution experience with 600 patients.
Our institutional experience with the use of hyperfractionated radiation therapy (RT) alone or concurrently with chemotherapy (RT-CHT) in Stage III non-small-cell lung cancer was reviewed. ⋯ Compared to the majority of existing phase II and III studies, this study reconfirmed the excellent results achieved with concurrent RT-CHT, including low toxicity. Concurrent RT-CHT results in survival benefit primarily by increasing LPFS, not DMFS.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2012
Spine stereotactic body radiotherapy utilizing cone-beam CT image-guidance with a robotic couch: intrafraction motion analysis accounting for all six degrees of freedom.
To evaluate the residual setup error and intrafraction motion following kilovoltage cone-beam CT (CBCT) image guidance, for immobilized spine stereotactic body radiotherapy (SBRT) patients, with positioning corrected for in all six degrees of freedom. ⋯ Near-rigid body immobilization, intrafraction CBCT imaging approximately every 15-20 min, and strict repositioning thresholds in six degrees of freedom yields minimal intrafraction motion allowing for safe spine SBRT delivery.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2012
Comparative StudyBiological optimization in volumetric modulated arc radiotherapy for prostate carcinoma.
To investigate the potential benefits achievable with biological optimization for modulated volumetric arc (VMAT) treatments of prostate carcinoma. ⋯ Biological optimization can significantly increase the organs-at-risk sparing in VMAT optimization for prostate carcinoma. In some particular cases, however, the DVH-based optimization resulted in superior treatment plans.