International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Role of prostate dose escalation in patients with greater than 15% risk of pelvic lymph node involvement.
To determine whether the radiation dose is a determinant of clinical outcome in patients with a lymph node risk of >15% treated using whole pelvic (WP), partial pelvic (PP), or prostate only (PO) fields. ⋯ The radiation dose was the most significant determinant of FFBF in patients with a lymph node risk >15% in the patient population studied. These data suggest that the primary tumor takes precedence over lymph node coverage or the use of STAD. Doses >70 Gy are of paramount importance in such intermediate- and high-risk patients.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Clinical TrialPosttreatment TNM staging is a prognostic indicator of survival and recurrence in tethered or fixed rectal carcinoma after preoperative chemotherapy and radiotherapy.
To evaluate the prognostic value of the posttreatment TNM stage as a predictor of outcome in locally advanced rectal cancers treated with preoperative chemotherapy and radiotherapy. ⋯ For patients who underwent preoperative chemoradiotherapy for locally advanced rectal cancer, the pCR TNM stage was a strong prognosticator of recurrence and survival. It can be used to identify high-risk patients for additional postoperative therapy.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Dose-response relationship in locoregional control for patients with stage II-III esophageal cancer treated with concurrent chemotherapy and radiotherapy.
To evaluate the correlation between radiation dose and locoregional control (LRC) for patients with Stage II-III unresectable esophageal cancer treated with concurrent chemotherapy and radiotherapy. ⋯ Our data suggested a positive correlation between radiation dose and LRC in the population studied. A higher radiation dose was associated with increased LRC and survival in the dose range studied. The data also suggested that better LRC was associated with a lower rate of distant metastasis. A threshold of tumor response to radiation dose might be present, as suggested by the flattened slope in the high-dose area on the dose-response curve. A carefully designed dose-escalation study is required to confirm this assumption.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Increased therapeutic ratio by 18FDG-PET CT planning in patients with clinical CT stage N2-N3M0 non-small-cell lung cancer: a modeling study.
With this modeling study, we wanted to estimate the potential gain from incorporating fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning in the radiotherapy treatment planning of CT Stage N2-N3M0 non-small-cell lung cancer (NSCLC) patients. ⋯ In this group of clinical CT Stage N2-N3 NSCLC patients, use of FDG-PET scanning information in radiotherapy planning reduced the radiation exposure of the esophagus and lung, and thus allowed significant radiation dose escalation while respecting all relevant normal tissue constraints. This, together with a reduced risk of geographic misses using PET-CT, led to an estimated increase in TCP from 13% to 18%. The results of this modeling study support clinical trials investigating incorporation of FDG-PET information in CT-based radiotherapy planning.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Adequate margins for random setup uncertainties in head-and-neck IMRT.
To investigate the effect of random setup uncertainties on the highly conformal dose distributions produced by intensity-modulated radiotherapy (IMRT) for clinical head-and-neck cancer patients and to determine adequate margins to account for those uncertainties. ⋯ The margins to account for random setup uncertainties, in our clinical IMRT solution, should be 1.5 mm and 3.0 mm in the case of sigma = 2 mm and sigma = 4 mm, respectively, for the CTV(primary). Larger margins (5.0 mm), however, should be applied to the CTV(elective), if the goal of treatment is a V(95) value of at least 99%.