International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
ReviewAnemia, tumor hypoxemia, and the cancer patient.
To review the impact of anemia/tumor hypoxemia on the quality of life and survival in cancer patients, and to assess the problems associated with the correction of this difficulty. ⋯ Anemia is a prevalent condition associated with cancer and its therapies. Proper Phase III trials are necessary to find the best way to correct anemia for specific patients. Future studies of erythropoietin must evaluate the possible anti-apoptotic effects by directly assessing the tumor for erythropoietin receptors or the presence of the JAK2/STAT5/BCL-X pathway. Due to the ability of transfusions to cause immunosuppression, most probably through inflammatory pathways, it may be best to study the effects of transfusion with the prolonged use of anti-inflammatory medications.
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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
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
Neoadjuvant hormone therapy and external-beam radiation for localized high-risk prostate cancer: the importance of PSA nadir before radiation.
To examine the impact of various patient, disease, and treatment characteristics on outcome in patients treated with neoadjuvant hormone therapy (NAHT) and external-beam radiation therapy (EBRT) for clinically localized, high-risk prostate adenocarcinoma (initial prostate-specific antigen [PSA] level >20, Gleason score 8-10 or Stage > or = T3). ⋯ Improved bDFS in patients with high-risk prostate cancer was associated with lower initial PSA level, lower Gleason score, and lower preradiation PSA level. The duration of NAHT did not have an impact on outcomes, but the preradiation PSA was an important predictor of bDFS in high-risk patients.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2005
Functional outcome of patients with benign meningioma treated by 3D conformal irradiation with a combination of photons and protons.
To evaluate efficacy and tolerance of external fractionated combination of photon and proton radiation therapy (RT) for intracranial benign meningiomas. ⋯ These results stressed the clinical efficacy of fractionated-associated photon-proton RT in the treatment of meningiomas, especially on cranial nerve palsies, without severe toxicity in almost all patients.