International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · May 1996
Lateral rectal shielding reduces late rectal morbidity following high dose three-dimensional conformal radiation therapy for clinically localized prostate cancer: further evidence for a significant dose effect.
Using conventional treatment methods for the treatment of clinically localized prostate cancer central axis doses must be limited to 65-70 Gray (Gy) to prevent significant damage to nearby normal tissues. A fundamental hypothesis of three-dimensional conformal radiation therapy (3DCRT) is that, by defining the target organ(s) accurately in three dimensions, it is possible to deliver higher doses to the target without a significant increase in normal tissue complications. This study examines whether this hypothesis holds true and whether a simple modification of treatment technique can reduce the incidence of late rectal morbidity in patients with prostate cancer treated with 3DCRT to minimum planning target volume (PTV) doses of 71-75 Gy. ⋯ The incidence of late rectal morbidity with 3DCRT to minimum PTV doses of 71-75 Gy is acceptable and to date no Grade 4-5 rectal morbidities have been observed. In our experience, higher doses to the center of the prostate are associated with an increased likelihood of developing Grade 2-3 rectal morbidity but treatment techniques that reduce the total dose to the anterior rectal wall have reduced the incidence of late rectal morbidity. If clinical studies indicate improved tumor control with minimum PTV doses above 71 Gy, then dose escalation above 76 Gy to the center of the prostate should be pursued cautiously with treatment techniques that limit the total dose to the anterior rectal wall.
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Int. J. Radiat. Oncol. Biol. Phys. · May 1996
Analysis of localization errors in the definition of the mantle field using a beam's eye view treatment-planning system.
Reports of the treatment of Hodgkin's disease (HD) with radiotherapy using the mantle field technique have demonstrated that coverage of disease by the field blocks significantly compromises outcome. It is our hypothesis that the availability of computerized tomography images reduces the incidence of localization error, and that the use of beam's eye view treatment planning techniques may further improve localization. The purpose of this report is to assess the possible contribution of a three-dimensional treatment-planning system to tumor localization and mantle block drawing in patients with HD. ⋯ The availability of CT imaging offers an advantage in the outlining of the mantle field in the treatment of Hodgkin's disease. When the error rate is evaluated using a beam's eye view treatment planning system, a significant proportion of tumors may be overlapped by the outlined mantle blocks even when CT images are available for reference. The use of beam's eye view treatment planning in mantle field definition, especially for tumors in the axillary region, may reduce the incidence of geographic misses.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 1996
Clinical Trial Controlled Clinical TrialEarly evaluation of abdominal/hepatic irradiation and 5-fluorouracil/leucovorin infusion after pancreaticoduodenectomy.
To describe the toxicities of a combined modality adjuvant regimen for patients with resectable periampullary adenocarcinoma. ⋯ These data indicate that adjuvant therapy with concomitant large-field radiation and infusional chemotherapy is feasible and associated with mangeable toxicities in patients undergoing pancreaticoduodenectomy for periampullary adenocarcinoma. Improvement in survival over other adjuvant regimens has not thus far been observed. Modification of this strategy may be required.
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To evaluate the prognostic factors and the ophthalmologic follow-up on cataract formation following total body irradiation (TBI) prior to bone marrow transplantation (BMT). ⋯ Among the abovementioned TBI parameters, high instantaneous dose rate seems to be the main risk factor of cataract formation, and the administration of heparin appears to have a protective role in cataractogenesis. On the other hand, ionizing radiation seems to have a protective effect on posterior capsule opacification following extracapsular cataract extraction and intraocular lens implantation.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 1996
Multicenter StudyA multiinstitutional outcome and prognostic factor analysis of radiosurgery for resectable single brain metastasis.
Recent randomized trials of selected patients with single brain metastasis comparing resection followed by whole-brain radiotherapy (WBRT) to WBRT alone have shown a statistically significant survival advantage for surgery and WBRT. A multiinstitutional retrospective study was performed, which identified comparable patients who were treated with stereotactic radiosurgery (RS) and WBRT. ⋯ The RS in conjunction with WBRT for single brain metastasis can produce substantial functional survival, especially in patients with good performance status and without extracranial metastasis. These results are comparable to recent randomized trials of resection and WBRT. The advantages of RS over surgery in terms of cost, hospitalization, morbidity, and wider applicability strongly suggest that a randomized trial to compare RS with surgery is warranted.