International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2005
Review Clinical TrialDose-volume analysis of predictors for chronic rectal toxicity after treatment of prostate cancer with adaptive image-guided radiotherapy.
We analyzed our experience treating localized prostate cancer with image-guided off-line correction with adaptive high-dose radiotherapy (ART) in our Phase II dose escalation study to identify factors predictive of chronic rectal toxicity. ⋯ In our ART dose escalation study, rectal wall or rectum relative > or =V50 are closely predictive for chronic rectal toxicity. If rectal dose-volume histogram constraints are used to select the dose level, the risk of chronic rectal toxicity will reflect the risk of toxicity of the selected constraint rather than the dose selected as found in our study using an adaptive process. To select the prescribed dose, different dose-volume histogram constraints may be used including the rectal wall V70. Patients experiencing acute rectal toxicity are more likely to experience chronic toxicity.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2005
ReviewVaginal brachytherapy alone is sufficient adjuvant treatment of surgical stage I endometrial cancer.
To determine the efficacy and complications of adjuvant vaginal high-dose-rate brachytherapy alone for patients with Stage I endometrial cancer in whom complete surgical staging had been performed. ⋯ Adjuvant vaginal high-dose-rate brachytherapy alone may be a safe and effective alternative to pelvic external beam radiotherapy for surgical Stage I endometrial cancer.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2005
Comparative StudyImportance of protocol target definition on the ability to spare normal tissue: an IMRT and 3D-CRT planning comparison for intraorbital tumors.
We selected five intraorbital tumor sites that are frequently found in clinical practice in children diagnosed with orbital rhabdomyosarcoma and performed three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated photon radiotherapy (IMRT) planning. Results of target coverage and doses to critical structures were compared. The goal of this study was to evaluate and to document realistic expectations as to organ-sparing capabilities of modern radiation therapy planning technologies with a focus on lens-sparing irradiation. Furthermore, we investigated potential added benefits of IMRT compared with 3D-CRT and the influence of protocol volume criteria definitions on the ability to obtain normal tissue dose sparing using the orbit as an example of a complex anatomic site. ⋯ Strict adherence to IRS-V protocol criteria prohibits at present lens sparing within compliance criteria for the majority of intraorbital tumor locations because of protocol-specific CTV and PTV target definitions. Changing protocol definitions by prescribing to the volume rather than to a dose constraint, IMRT planning significantly reduced lens doses. This was not accomplished to the same degree with 3D-CRT. Our study underlines the importance of appropriate selection of planning objectives to maximize the specific capabilities and advantages of IMRT in terms of sufficient target coverage and simultaneous sparing of critical structures. Our results can add to the ongoing discussion in the design of future 3D-CRT/IMRT protocols.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2005
An association between preoperative anemia and decreased survival in early-stage non-small-cell lung cancer patients treated with surgery alone.
Surgical resection is the mainstay of therapy for patients presenting with Stage I and II non-small-cell lung cancer (NSCLC). Despite optimal staging and surgery, these patients are still at significant risk for failure. The purpose of this study is to report a retrospective analysis of the outcome of patients treated with surgery alone, as well as to analyze prognostic factors associated with survival. ⋯ In our cohort of mostly Stage I NSCLC patients treated with surgery only, preoperative Hgb <12 mg/dL predicted for worse outcome. This effect was observed even in the traditionally low-risk subgroup of completely resected stage IA patients. Much has been written in the literature about anemia causing possible worsening of tumor hypoxia within solid tumors, thereby increasing radio-resistance. This has been a popular argument to explain poorer outcomes of anemic patients with solid tumors who undergo radiotherapy. However, our data suggest that anemia may be a sign of a more aggressive tumor that is at an increased risk of failure independent of the treatment modality.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2005
TLD skin dose measurements and acute and late effects after lumpectomy and high-dose-rate brachytherapy only for early breast cancer.
This report examines the relationships between measured skin doses and the acute and late skin and soft tissue changes in a pilot study of lumpectomy and high-dose-rate brachytherapy only for breast cancer. ⋯ For high-dose-rate brachytherapy to the lumpectomy site, TLD skin dose was significantly related to acute skin reaction and to pigmentation and telangiectasia at 60 months. An acute skin reaction was also significantly associated with the development of telangiectasia at 60 months. TLD skin dose measurement may allow modification of the brachytherapy implant geometry (dwell times and position) to minimize late skin toxicity.