International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1998
Randomized Controlled Trial Clinical TrialPortal imaging protocol for radical dose-escalated radiotherapy treatment of prostate cancer.
The use of escalated radiation doses to improve local control in conformal radiotherapy of prostatic cancer is becoming the focus of many centers. There are, however, increased side effects associated with increased radiotherapy doses that are believed to be dependent on the volume of normal tissue irradiated. For this reason, accurate patient positioning, CT planning with 3D reconstruction of volumes of interest, clear definition of treatment margins and verification of treatment fields are necessary components of the quality control for these procedures. In this study electronic portal images are used to (a) evaluate the magnitude and effect of the setup errors encountered in patient positioning techniques, and (b) verify the multileaf collimator (MLC) field patterns for each of the treatment fields. ⋯ The systematic errors can easily be identified and corrected for in the early stages of the Phase I treatment course. The time trends observed during the course of Phase I in conjunction with the isocenter verification at the start of Phase II give good prediction of the accuracy of the setup during Phase II, where visibility of identifiable structures is reduced in the small fields. The acquisition and inspection of the portal images for the small Phase I fields has been found to be an effective way of keeping a record of the MLC field patterns used. Incorporation of the distribution of the setup errors into the planning system also gives a clearer picture of how the prescribed dose was delivered. This information can be useful in dose-escalation studies in determining the relationship between the local control or morbidity rates and prescribed dose.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1998
Multicenter StudyRadiotherapy alone for medically inoperable stage I non-small-cell lung cancer: the Duke experience.
To review our experience treating clinical Stage I non-small-cell lung carcinoma with radiotherapy alone using modern techniques and staging. The effect of dose and volume on outcome is to be analyzed. ⋯ Patients with clinical Stage I medically inoperable non-small-cell lung cancer treated with contemporary radiotherapy alone achieved a 5-year cause-specific survival of 32%. Uncontrolled lung cancer was the primary cause of death in these patients, and local failure alone represented the most common mode of failure (42%). Patients who were locally controlled had a significantly improved cause-specific survival over those who failed locally. Because higher doses of radiotherapy appear to provide improved local control, studies of dose escalation are warranted until dose-limiting toxicity is observed.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1998
Comparative StudySociodemographic analysis of patients in radiation therapy oncology group clinical trials.
To assess the degree to which the sociodemographic characteristics of patients enrolled in Radiation Therapy Oncology Group (RTOG) clinical trails are representative of the general population. ⋯ Comparisons with the U.S. Census and SEER show that African-Americans are proportionally well represented in cancer clinical trials conducted by the Radiation Therapy Oncology Group. The comparative analysis indicates that all educational levels in each age group of African-Americans generally mirror the U.S. Census, with one exception. The exception is a significant overrepresentation of less-educated African-Americans in the youngest age category. This exception is counter to the expectation that better-educated patients are more likely to enroll in trials. When compared with SEER data, the RTOG trials either parallel or overrepresent African-American men and women, with the only exception being in lung cancer, where men are underrepresented. These results show that, in comparison to the Census and SEER data, the RTOG has fulfilled its commitment to enroll African-American patients in its clinical trials.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1998
Radiation therapy and hydroxyurea followed by the combination of 6-thioguanine and BCNU for the treatment of primary malignant brain tumors.
This study was designed to evaluate a combined modality treatment for malignant gliomas using radiation therapy with a radiosensitizer and an adjuvant chemotherapy regimen designed to modify resistance to BNCU. ⋯ This therapy was no more effective in patients with GBM than other reported series. In patients with malignant gliomas other than GBM, prolonged progression-free and overall survival is noted, without a median survival reached at the time of this report. In this subset of AG patients, survival is comparable to recent studies using halogenated prymidines during radiation and Procarbazine, CCNU, and Vincristine (PCV) as adjuvant chemotherapy.