International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2006
Comparative StudyIs intensity-modulated radiotherapy better than conventional radiation treatment and three-dimensional conformal radiotherapy for mediastinal masses in patients with Hodgkin's disease, and is there a role for beam orientation optimization and dose constraints assigned to virtual volumes?
To evaluate the role of beam orientation optimization and the role of virtual volumes (VVs) aimed at protecting adjacent organs at risk (OARs), and to compare various intensity-modulated radiotherapy (IMRT) setups with conventional treatment with anterior and posterior fields and three-dimensional conformal radiotherapy (3D-CRT). ⋯ The 5FEQ IMRT plan with dose constraints assigned to the PTV and VV allows better dose conformation than conventional treatment and 3D-CRT, notably with better protection of the heart and coronary arteries. Of concern is the "spreading out" of low doses to the rest of the patient's body.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2006
STI571 (Gleevec) improves tumor growth delay and survival in irradiated mouse models of glioblastoma.
Glioblastoma multiforme (GBM) is a devastating brain neoplasm that is essentially incurable. Although radiation therapy prolongs survival, GBMs progress within areas of irradiation. Recent studies in invertebrates have shown that STI571 (Gleevec; Novartis, East Hanover, NJ) enhances the cytotoxicity of ionizing radiation. In the present study, the effectiveness of STI571 in combination with radiation was studied in mouse models of GBM. ⋯ These findings suggest that STI571 has the potential to augment radiotherapy and thereby improve median survival.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2006
Comparison of day 0 and day 14 dosimetry for permanent prostate implants using stranded seeds.
To determine, using MRI-based dosimetry (Day 0 and Day 14), whether clinically significant changes in the dose to the prostate and critical adjacent structures occur between Day 0 and 14, and to determine to what degree any changes in dosimetry are due to swelling or its resolution. ⋯ The dose to the prostate changed between Days 0 and 14 in most patients, resulting in a change in clinical status (acceptable or unacceptable) in 12 of 28 patients. Profound increases in normal tissue doses may make dose and toxicity correlations using Day 0 dosimetry difficult. No relationship was found between the prostate volume change and D90 change, and, in 11 patients, a paradoxic dosimetric result was noted. A differential z-axis shift of stranded seeds vs. prostate had a greater impact on final dosimetry and dose to critical adjacent tissues than did prostate swelling. These findings challenge the model that swelling is the principal cause of dosimetric changes after implantation. Stranded seeds may have contributed to this outcome. On the basis of these findings, a change in technique to avoid placement of stranded seeds inferior to the prostate apex has been adopted. These results may not apply to implants using single seeds within the prostate.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2006
Multicenter StudyPrognostic factors predicting functional outcomes, recurrence-free survival, and overall survival after radiotherapy for metastatic spinal cord compression in breast cancer patients.
To identify significant prognostic factors after irradiation of metastatic spinal cord compression (MSCC) in 335 breast cancer patients. ⋯ Outcomes and survival after RT for MSCC in breast cancer patients are associated with several prognostic factors. Patients with poor expected survival may be treated with shorter-course RT to keep the overall treatment time short. If survival is expected to be relatively favorable, longer-course RT appears preferable, because it is associated with fewer MSCC recurrences.