International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Dec 2003
Clinical TrialOngoing clinical experience utilizing 3D conformal external beam radiotherapy to deliver partial-breast irradiation in patients with early-stage breast cancer treated with breast-conserving therapy.
We present our ongoing clinical experience utilizing 3D conformal radiation therapy (3D-CRT) to deliver partial-breast irradiation (PBI) in patients with early-stage breast cancer treated with breast-conserving therapy. ⋯ Utilizing 3D-CRT to deliver PBI is technically feasible, and acute toxicity to date has been minimal. Additional follow-up will be needed to assess the long-term effects of these larger fraction sizes on normal-tissue sequelae and the impact of this fractionation schedule on treatment efficacy.
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Int. J. Radiat. Oncol. Biol. Phys. · Dec 2003
Clinical TrialThree-dimensional conformal radiation therapy for non-small-cell lung cancer: a phase I/II dose escalation clinical trial.
A prospective Phase I/II dose escalation study was conducted to determine the maximum tolerated dose (MTD) in three-dimensional conformal radiation therapy (3D-CRT) for non-small-cell lung cancer (NSCLC). ⋯ Although MFT was 18 months, it had not yet been declared because a longer follow-up was needed to observe the late complications. The 2-year overall survival of 44% was very encouraging and implied that 3D-CRT combined with chemotherapy would improve the outcome for locally advanced NSCLC.
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Int. J. Radiat. Oncol. Biol. Phys. · Dec 2003
Clinical significance of 3D reconstruction of arteriovenous malformation using digital subtraction angiography and its modification with CT information in stereotactic radiosurgery.
A three-dimensional (3D) reconstruction method of arteriovenous malformation (AVM) nidus from digital subtraction angiography (DSA) in combination with CT and/or MRI was developed, and its usefulness was evaluated in this study. ⋯ The superposition of the segmented DSA information on CT was shown to be an important tool to determine the precise shape of the nidus and is suggested to be useful to reduce partial occlusion of the AVM or radiation complications in radiosurgery.
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Int. J. Radiat. Oncol. Biol. Phys. · Dec 2003
NS 398 radiosensitizes an HNSCC cell line by possibly inhibiting radiation-induced expression of COX-2.
Cyclooxygenase-2 (COX-2) protein is frequently elevated in squamous cell carcinoma of the head and neck (HNSCC). The aim of this study was to determine if COX-2 inhibitors have radiosensitizing effects in HNSCC and understand the mechanism by which this occurs. ⋯ The radiosensitizing effect of NS398 could be due to inhibition of radiation-induced COX-2 upregulation by this drug. NS398, known as an inhibitor of COX-2 enzyme activity, down-regulated COX-2 protein expression, which may indicate that NS398 can act upstream of COX-2, and this change appears to be post-transcriptional.
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Int. J. Radiat. Oncol. Biol. Phys. · Dec 2003
Assessment of different IMRT boost delivery methods on target coverage and normal-tissue sparing.
Because of biologic, medical, and sometimes logistic reasons, patients may be treated with 3D conformal therapy or intensity-modulated radiation therapy (IMRT) for the initial treatment volume (PTV(1)) followed by a sequential IMRT boost dose delivered to the boost volume (PTV(2)). In some patients, both PTV(1) and PTV(2) may be simultaneously treated by IMRT (simultaneous integrated boost technique). The purpose of this work was to assess the sequential and simultaneous integrated boost IMRT delivery techniques on target coverage and normal-tissue sparing. ⋯ For equal PTV coverage, both sequential-IMRT techniques demonstrated moderately improved sparing of the critical structures. SIB-IMRT, however, markedly reduced doses to the critical structures for most of the cases considered in this study. The conformality of the SIB-IMRT plans was also much superior to that obtained with both sequential-IMRT techniques. The improved conformality gained with SIB-IMRT may suggest that the dose to nontarget tissues will be lower.