International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
GuidelineTreatment planning guidelines regarding the use of CT/PET-guided IMRT for cervical carcinoma with positive paraaortic lymph nodes.
Computed tomography (CT)/positron emission tomography (PET)-guided intensity-modulated radiotherapy of the paraaortic lymph nodes (PALNs) has been proposed for patients with cervical carcinoma and paraaortic metastasis. This investigation attempted to determine the guidelines regarding the selection of appropriate treatment parameters (e.g., number of beams, beam geometry) and organ-specific parameters (e.g., importance weighting and tolerance dose) for intensity-modulated radiotherapy planning for the PALNs. ⋯ We successfully developed treatment plans that deliver 59.4 Gy to the positive PALNs and 50.4 Gy to the paraaortic region using CT/PET-guided intensity-modulated radiotherapy.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Concurrent chemotherapy and reduced-dose cranial spinal irradiation followed by conformal posterior fossa tumor bed boost for average-risk medulloblastoma: efficacy and patterns of failure.
To review the efficacy and patterns of failure in average-risk medulloblastoma patients treated with concurrent chemotherapy and reduced-dose cranial spinal irradiation and a conformal tumor bed boost. ⋯ The treatment of average-risk medulloblastoma with chemotherapy, reduced-dose cranial spinal irradiation, and a conformal tumor bed boost results in survival rates and local control rates comparable to those in contemporary studies. A reduction in the amount of posterior fossa treated to the high dose is possible. These results need to be corroborated in a large, cooperative group study.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Dosimetric correlates for acute esophagitis in patients treated with radiotherapy for lung carcinoma.
Acute esophagitis is a common complication of radiotherapy (RT) for non-small-cell carcinoma of the lung. Previous reports have related esophagitis to dosimetric parameters such as the length of the irradiated esophagus, maximal dose, or volume of the organ treated beyond a threshold dose. However, when using oblique beams, a portion of the esophageal circumference may be outside the treated field, resulting in partial esophageal irradiation. Therefore, our aim was to determine whether the irradiated esophageal surface area and/or esophageal volume are predictive of acute esophagitis in relation to other clinical and treatment-related factors. ⋯ The esophageal surface area receiving > or =55 Gy, the esophageal volume receiving > or =60 Gy, and the use of concurrent chemotherapy were the most statistically significant predictive factors for early esophagitis. Adequate dosimetric coverage of the planning target volume remains the goal of RT planning. High values of A(55) and/or V(60) are indicative of the development of acute esophagitis and may indicate a need to explore alternative RT planning options.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Importance of margin extent as a predictor of outcome after adjuvant radiotherapy for Gleason score 7 pT3N0 prostate cancer.
To evaluate, in Gleason score 7, pT3N0 prostate cancer patients with positive surgical margins, the predictors of progression-free survival and to identify a patient subgroup that would benefit from immediate adjuvant postoperative radiotherapy (ART). ⋯ These data suggest that the amount of microscopic residual tumor significantly affects bNED after radical prostatectomy for Gleason score 7, pT3N0 prostate cancer. In addition, men with pathologic evidence of microscopic local disease appear to benefit from early ART compared with untreated controls.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Evaluation of the influence of breathing on the movement and modeling of lung tumors.
Respiration causes movement and potential shape change in lung tumors that are not fully appreciated using conventional free-breathing CT models for radiotherapy planning. Although target expansion has the potential to ensure proper tumor coverage in the face of motion on a free-breathing CT scan, large variations in how individual patients' tumors move may make such expansions difficult to uniformly define. In addition, excessive expansion may result in the unnecessary inclusion of normal lung in the treated volume. This study was designed to evaluate the influence of breathing movement on tumors and to assess the validity of the free-breathing CT scan for target delineation in the lung. ⋯ Traditional methods of expanding the GTV to CTV by 1 cm are less than ideal. This method tends to include more normal lung than necessary and may lead to marginal miss. Interpatient tumor movement variations further prohibit defining a simple rule for nonuniform expansion that would minimize the volume of normal lung in the target. Although the development of target volumes by combining information from breath-hold CT scans at inhale and exhale states shows some promise in minimizing excess lung irradiated while maintaining adequate tumor coverage, further tests of breathing reproducibility need to be performed to provide a confident baseline for defining target expansions by this technique.