International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 1997
Adaptive modification of treatment planning to minimize the deleterious effects of treatment setup errors.
Using daily setup variation measured from an electronic portal imaging device (EPID), radiation treatment of the individual patient can be adaptively reoptimized during the course of therapy. In this study, daily portal images were retrospectively examined to: (a) determine the number of initial days of portal imaging required to give adequate prediction of the systematic and random setup errors; and (b) explore the potential of using the prediction as feedback to reoptimize the individual treatment part-way through the treatment course. ⋯ The adaptive modification process represents a different approach for use of on-line portal images. The portal imaging information from the initial treatments is used as feedback for reoptimization of the treatment plan, rather than adjustment of the treatment setup. Results from the retrospective study show that the treatment of individual patient can be improved with the adaptive modification process.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 1997
Stage T1-2 prostate cancer: a multivariate analysis of factors affecting biochemical and clinical failures after radical prostatectomy.
Prostate-specific antigen (PSA) is extensively used in case selection and outcome evaluation after treatment of clinically localized prostate cancer. Careful case selection can have a profound impact on pathologic findings and ultimate outcome. In addition, salvage treatment is frequently initiated at the time of biochemical relapse rather than clinical recurrence. Consequently, patterns of failure can be significantly altered compared to previous times when PSA was not available. To better understand the impact of PSA on pathologic findings, outcome, and salvage treatment, we reviewed our experience in the PSA era with clinical Stage T1-2 prostate cancer treated with radical prostatectomy. ⋯ Pretreatment PSA is the most potent clinical factor independently predicting biochemical relapse, thereby allowing markedly better case selection. Achieving negative margins, even in relatively advanced disease, provides excellent lon
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 1997
Prognostic factors in adult soft-tissue sarcomas of the head and neck.
The main objectives of this study were (a) to review the treatment results of primary head and neck soft-tissue sarcoma at our institution, (b) to identify important prognostic factors in local control and survival, and (c) to assess the efficacy of salvage therapy. ⋯ Tumor size and grade were important predictors for local control. Age, grade, adequacy of surgery, and status of surgical margins were significant prognostic factors for survival. There was a trend of improved local control with combined surgery and radiotherapy compared to either modality alone for high-risk patients. Radiotherapy alone with doses < or = 65 Gy was insufficient for control of gross disease. Aggressive salvage therapy was worthwhile in patients whose disease was uncontrolled after the initial treatment.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 1997
Is machine energy (4-8 MV) associated with outcome for stage I-II breast cancer patients?
To assess the relationship between machine energy (4-8 MV) and treatment outcome in patients treated with conservative surgery and radiation therapy. ⋯ We conclude that machine energy over the range of 4 to 8 MV does not significantly affect treatment outcome. Specifically, it was feasible to treat patients with large chest wall separations using an 8 MV machine without an increase in skin recurrences and with the improved dose homogeneity afforded by 8 MV machines as compared with those of lower energies.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 1997
Locoregional recurrence of breast cancer following mastectomy: always a fatal event? Results of univariate and multivariate analysis.
The outcome of patients with local-regional breast cancer recurrence after mastectomy often is described as fatal. However, certain subgroups with favorable prognoses are thought to exist. To determine these favorable subgroups, we analyzed prognostic factors for their influence on postrecurrence survival by univariate and multivariate analysis. ⋯ We conclude that locoregional recurrence of breast cancer following mastectomy is not always a sign of systemic disease. Our data support previous findings, that subgroups with favorable prognosis exist and they still have a chance for cure, demanding comprehensive local treatment. (ABSTR