International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2004
Phenomenologic model describing flow reduction for parotid gland irradiation with intensity-modulated radiotherapy: evidence of significant recovery effect.
To develop a model describing the relationship between the parotid gland radiation dose and salivary flow reduction. Salivary function was described by the "relative flow reduction" (RFR)-a continuous variable in contrast to the traditional binary response used in normal tissue complication probability estimations. ⋯ We observed a strong relationship between the generalized mean parotid gland dose and RFR. The threshold dose increased markedly between the early and late measurements, indicating a statistically significant recovery effect in this tissue. Compared with unstimulated flow, the RFR for stimulated flow was not described as well by the model, because the effect of the stimulant was not included in the model.
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To evaluate the relationship between total radiation dose and overall treatment time (OTT) with the treatment outcome, with adjustment for selected clinical factors, in patients with Stage T2-T3 bladder cancer treated with curative radiotherapy (RT). ⋯ The results of our study showed that the treatment outcome after RT for bladder cancer depends mainly on clinical factors: hemoglobin level and bladder capacity before RT, and clinical T stage. An increase in the total radiation dose seemed to be associated with a better treatment outcome. The effect of the OTT was difficult to define, because it was influenced by other prognostic factors.
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2004
Late effects of radiotherapy for pediatric extremity sarcomas.
To determine the long-term effects of radiotherapy (RT) in children treated for extremity sarcoma. ⋯ Although most children treated with RT for a pediatric extremity sarcoma have minimal late toxicity by LENT-SOMA scale, approximately half required a surgical procedure to correct a late effect. A fracture in the irradiated bone may be the presenting sign or may precede a radiation-induced bone malignancy, as seen in 3 of the patients in this study.
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2004
Increased cure rate of glioblastoma using concurrent therapy with radiotherapy and arsenic trioxide.
Patients with glioblastoma multiforme (GBM) do extremely poorly despite aggressive therapy with surgery, radiotherapy (RT), and chemotherapy. In an effort to increase the efficacy of therapy for GBM, we studied the efficacy of arsenic trioxide (ATO) combined with high-dose RT in GBM cells in vitro and GBM xenograft tumors in nude mice. ⋯ These results have demonstrated that ATO increases intracellular levels of reactive oxygen species, induces apoptosis, and enhances the radiation cell killing of GBM cells. RT combined with ATO was an effective treatment for GBM tumors in this preclinical model. These preclinical results are encouraging and provide a rationale for further study of ATO combined with RT for the treatment of GBM and other histologic types of brain cancer using a variety of RT schemes.