International journal of radiation oncology, biology, physics
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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.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Initiation of a teleradiotherapeutic network for patients in German lymphoma studies.
Deviations of radiation treatment portals and dose from prospective treatment plans are unfavorable prognostic factors for lymphoma patients. Therefore, an extensive radiotherapy quality assurance program is used in the ongoing German lymphoma studies. The introduction of teleradiotherapy offered the opportunity to optimize and simplify the workflow of these quality assurance programs. The purpose of this report was to evaluate the feasibility of teleradiotherapy and to describe our experiences with these innovative tools. ⋯ The introduction of teleradiotherapy improved the dialog between the radiotherapy reference centers and study centers and thus contributed toward high radiotherapy quality for lymphoma patients in Germany.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Case Reports Comparative StudyAdvantage of protons compared to conventional X-ray or IMRT in the treatment of a pediatric patient with medulloblastoma.
To compare treatment plans from standard photon therapy to intensity modulated X-rays (IMRT) and protons for craniospinal axis irradiation and posterior fossa boost in a patient with medulloblastoma. ⋯ The present study clearly demonstrates the advantage of conformal radiation methods for the treatment of posterior fossa and spinal column in children with medulloblastoma, when compared to conventional X-rays. Of the two conformal treatment methods evaluated, protons were found to be superior to IMRT.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
ReviewEpidermal growth factor receptor and response of head-and-neck carcinoma to therapy.
To present an overview of the significance of erbB tyrosine kinase family members as prognostic-predictive factors and as targets of therapeutic intervention in patients with head-and-neck carcinomas (HNCs). ⋯ Members of the erbB receptor tyrosine kinase family, particularly EGFR, were found to be a strong biomarker for poor prognosis and HNC resistance to RT. The available data showed that EGFR antagonists given as single modality therapies yield rather limited antitumor activity. The results of trials testing the efficacy of combining EGFR antagonist with RT or chemotherapy will emerge within the next few years.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Multicenter StudyRenal insufficiency in patients with hematologic malignancies undergoing total body irradiation and bone marrow transplantation: a prospective assessment.
Patients with malignant hematologic disorders undergoing bone marrow transplantation (BMT) may develop renal insufficiency. A study was undertaken to assess prospectively the subclinical renal function changes with radioisotopic methods in patients undergoing BMT for hematologic malignancies. ⋯ Early post-BMT renal dysfunction is associated with the administration of potentially nephrotoxic drugs. An inverse correlation with the prescribed TBI dose was observed; patients whose kidneys received 10 Gy through the use of partial shielding blocks had significantly greater renal dysfunction at 4 months. The administration of potentially nephrotoxic contrast agents used in radiotherapy treatment planning may be responsible for the latter observation. Prostaglandin E(1) use correlated with a significant reduction in ERPF at both 4 and 12-18 months.