International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2002
Performance evaluation of an 85-cm-bore X-ray computed tomography scanner designed for radiation oncology and comparison with current diagnostic CT scanners.
The demand for computed tomography (CT) virtual simulation is constantly increasing with the wider adoption of three-dimensional conformal and intensity-modulated radiation therapy. Virtual simulation CT studies are typically acquired on conventional diagnostic scanners equipped with an external patient positioning laser system and specialized planning and visualization software. Virtual simulation technology has matured to a point where conventional simulators may be replaced with CT scanners. However, diagnostic CT scanner gantry bores (typically 65-70 cm) can present an obstacle to the CT simulation process by limiting patient positions, compared to those that can be attained in a conventional simulator. For example, breast cancer patients cannot always be scanned in the treatment position without compromising reproducibility and appropriateness of setup. Extremely large patients or patients requiring special immobilization or large setup devices are often unable to enter the limited-bore gantry. A dedicated 85-cm-bore radiation oncology CT scanner has the potential to eliminate these problems. The scanner should provide diagnostic-quality images at diagnostic-comparable dose levels. The purpose of this study was to independently evaluate the performance of a novel 85-cm-bore CT X-ray scanner designed specifically for radiation oncology and compare it against diagnostic-type, 70-cm-bore scanners that may be used in the same setting. ⋯ The overall imaging performance and mechanical integrity of the 85-cm-bore scanner are comparable to those of conventional diagnostic scanners that may be employed in a radiation oncology setting.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2002
Locoregional failure of postmastectomy patients with 1-3 positive axillary lymph nodes without adjuvant radiotherapy.
To analyze the incidence and risk factors for locoregional recurrence (LRR) in patients with breast cancer who had T1 or T2 primary tumor and 1-3 histologically involved axillary lymph nodes treated with modified radical mastectomy without adjuvant radiotherapy (RT). ⋯ LRR after mastectomy is not only a substantial clinical problem, but has a significant impact on the outcome of patients with T1 or T2 primary tumor and 1-3 positive axillary nodes. Patients with risk factors for LRR may need adjuvant RT. Randomized trials are warranted to determine the potential benefit of postmastectomy RT on the survival of patients with a T1 or T2 primary tumor and 1-3 positive nodes.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2002
Comparative StudyComorbidity and KPS are independent prognostic factors in stage I non-small-cell lung cancer.
To determine the prognostic role of comorbidity in Stage I non-small-cell lung cancer (NSCLC) treated with surgery or radiotherapy (RT). ⋯ The presence of significant comorbidity and KPS of <70 are both important prognostic factors, but were found to be independent of each other in Stage I NSCLC. Therefore, comorbidity and KPS assessment are recommended when analyzing the prognostic effects of tumor or treatment-related factors on OS.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2002
Erectile function after permanent prostate brachytherapy.
To determine the incidence of potency preservation after permanent prostate brachytherapy using a validated patient-administered questionnaire and to evaluate the effect of multiple clinical and treatment parameters on penile erectile function. ⋯ Our results suggest that brachytherapy-induced ED is more common than previously reported and may be the result of obtaining patient information by means of a validated quality-of-life instrument by mail and not by personal interview. In multivariate analysis, only pretreatment potency, supplemental EBRT, and diabetes maintained statistical significance. Most patients with brachytherapy-induced ED responded favorably to sildenafil. Although the 6-year actuarial incidence of potency preservation was 39%, 52% of patients not receiving supplemental EBRT maintained potency. In addition, with pharmacologic support, 92% of patients maintained potency.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2002
Impact of biochemical failure on overall survival after radiation therapy for localized prostate cancer in the PSA era.
To study the impact of biochemical failure on overall survival rates during the first 10 years after definitive radiotherapy for localized prostate cancer. ⋯ Biochemical failure after definitive radiotherapy for localized prostate cancer is not associated with increased mortality within the first 10 years after initial therapy, although a trend toward worse outcome was observed at 10 years. Longer follow-up from initial therapy is needed to fully understand the impact of biochemical failure on overall survival. With longer follow-up, significant differences might be observed at 15 or 20 years after therapy.