International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Radiochemotherapy in the conservative treatment of anal canal carcinoma: retrospective analysis of results and radiation dose effectiveness.
This retrospective analysis reports the results on patients with anal canal carcinoma treated by combined radiotherapy and chemotherapy. ⋯ This analysis suggests that the treatment scheme employed was effective for anal sphincter preservation and local control; however, the incidence of distant metastases was relatively high. The clinical stage was the main prognostic factor for overall survival. Local control was higher in patients treated with doses of more than 50 Gy at primary tumor. The high incidence of inguinal failure implies the need for elective RT in this region.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Review Meta AnalysisProposal of human spinal cord reirradiation dose based on collection of data from 40 patients.
Driven by numerous reports on recovery of occult radiation injury, reirradiation of the spinal cord today is considered a realistic option. In rodents, long-term recovery was observed to start at approximately 8 weeks. However, prospective clinical studies are lacking. Therefore, a combined analysis of all published clinical data might provide a valuable basis for future trials. ⋯ On the basis of these literature data (and with due caution), the risk of myelopathy appears small after < or =135.5 Gy(2) when the interval is not shorter than 6 months and the dose of each course is < or =98 Gy(2). We would recommend limiting the dose to this level, whenever technically feasible. However, it appears prudent to propose the collection of prospective data from a greater number of patients receiving doses in the range of 136-150 Gy(2) to assess the safety of higher retreatment doses for those patients in whom limited doses might compromise tumor control.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Clinical TrialThe impact of daily setup variations on head-and-neck intensity-modulated radiation therapy.
Intensity-modulated radiation therapy (IMRT) in the treatment of head-and-neck (H&N) cancer provides the opportunity to diminish normal tissue toxicity profiles and thereby enhance patient quality of life. However, highly conformal treatment techniques commonly establish steep dose gradients between tumor and avoidance structures. Daily setup variations can therefore significantly compromise the ultimate precision of idealized H&N IMRT delivery. This study provides a detailed analysis regarding the potential impact of daily setup variations on the overall integrity of H&N IMRT. ⋯ The successful implementation of H&N IMRT requires accurate and reproducible treatment delivery over a 6- to 7-week treatment course. The adverse impact of daily setup variation, which occurs routinely with conventional H&N masking techniques, may be considerably greater than recognized. Isocenter verification checks on two-dimensional orthogonal films may not sufficiently alert the clinician to the magnitude of three-dimensional offset vectors and the resultant impact on the quality of overall IMRT delivery. Unrecognized geographic miss and resultant target underdose may occur. Similarly, selected normal structures such as parotid glands may receive higher doses than intended. The results of this study suggest that more rigorous immobilization techniques than conventional masking and routine patient setup tracking methodologies are important for the accurate monitoring and successful delivery of high-quality IMRT for H&N cancer.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2005
Fractionated stereotactic radiotherapy in patients with benign or atypical intracranial meningioma: long-term experience and prognostic factors.
To analyze our long-term experience and prognostic factors after fractionated stereotactic radiotherapy (FSRT) in patients with benign or atypical intracranial meningioma. ⋯ These data have demonstrated that FSRT is an effective and safe treatment modality for local control of meningioma with a low risk of significant late toxicity. We identified the tumor volume, indication for FSRT, and histologic features of the meningioma as statistically significant prognostic factors.