International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2009
Accelerated hypofractionated intensity-modulated radiotherapy with concurrent and adjuvant temozolomide for patients with glioblastoma multiforme: a safety and efficacy analysis.
Despite multimodality treatments, the outcome of patients with glioblastoma multiforme remains poor. In an attempt to improve results, we have begun a program of accelerated hypofractionated intensity-modulated radiotherapy (hypo-IMRT) with concomitant and adjuvant temozolomide (TMZ). ⋯ The results of our study have shown that hypo-IMRT with concomitant and adjuvant TMZ is well tolerated with a useful 2-week shortening of radiotherapy. Despite a high number of patients with poor prognostic features (74.3% recursive partitioning analysis class V or VI), the median survival was comparable to that after standard radiotherapy fractionation schedules plus TMZ.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2009
Commissioning of volumetric modulated arc therapy (VMAT).
Volumetric modulated arc therapy (VMAT) involves the simultaneous use of dynamic multileaf collimator (DMLC) techniques and gantry arcing; appropriate quality assurance is therefore required. This article describes the development and implementation of procedures for commissioning VMAT on a commercial linear accelerator (Elekta PreciseBeam VMAT with MLCi and Beam Modulator heads). ⋯ VMAT has been successfully commissioned and has been introduced into clinical use. The Elekta DMLC has also been shown to be suitable for sliding window delivery.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2009
Conformity of LINAC-based stereotactic radiosurgery using dynamic conformal arcs and micro-multileaf collimator.
To assess the conformity of dynamic conformal arc linear accelerator-based stereotactic radiosurgery and to describe a standardized method of isodose surface (IDS) selection. ⋯ The CIs obtained with linear accelerator-based stereotactic radiosurgery are comparable to those previously reported for gamma knife stereotactic radiosurgery. Using a uniform method to select the sIDS, adequate target coverage was usually achievable with prescription to an IDS greater than that chosen by the treating physician (prescription IDS), providing sparing of normal tissue. Thus, the sIDS might aid physicians in identifying a prescription IDS that balances coverage and conformity.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2009
Resection followed by stereotactic radiosurgery to resection cavity for intracranial metastases.
In patients who undergo resection of central nervous system metastases, whole brain radiotherapy (WBRT) is added to reduce the rates of recurrence and neurologic death. However, the risk of late neurotoxicity has led many patients to decline WBRT. We offered adjuvant stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) as an alternative to select patients with resected brain metastases. ⋯ Our results suggest that for patients with newly diagnosed brain metastases treated with surgical resection, postoperative SRS/SRT to the resection cavity is a feasible option. WBRT can be reserved as salvage treatment with acceptable neurologic deficit-free survival.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2009
Randomized Controlled Trial Multicenter StudyFinal report of multicenter Canadian Phase III randomized trial of 3 versus 8 months of neoadjuvant androgen deprivation therapy before conventional-dose radiotherapy for clinically localized prostate cancer.
To evaluate the effect of 3 vs. 8 months of neoadjuvant hormonal therapy before conventional-dose radiotherapy (RT) on disease-free survival for localized prostate cancer. ⋯ A longer period of NHT before standard-dose RT did not alter the patterns of failure when combined with 66-Gy RT. High-risk patients in the 8-month arm had significant improvement in the 5-year disease-free survival rate.