International journal of radiation oncology, biology, physics
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Recently, low alpha/beta values of 1.2 and 1.5 Gy for prostate tumors have been derived from clinical results of external beam radiotherapy and of permanent implants of (125)I and (103)Pd. In the analyses the contributions of tumor repopulation, and edema as a result of inserting radioactive seeds in the prostate, have been ignored. In this paper we reanalyzed the clinical data and introduced the contribution of repopulation and edema. ⋯ It seems now that the alpha/beta value is low, 3.1-3.9 Gy, but not as low as the 1.2 and 1.5 Gy reported earlier.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2003
Multicenter Study Comparative StudyComparison of alternative biochemical failure definitions based on clinical outcome in 4839 prostate cancer patients treated by external beam radiotherapy between 1986 and 1995.
To assess the merit of the American Society for Therapeutic Radiology and Oncology (ASTRO) definition of biochemical failure after external beam radiotherapy for prostate cancer by testing alternative prostate-specific antigen (PSA) failure definitions against the "gold standard" of clinical failure and to study the effect of backdating the time of failure. ⋯ The ASTRO failure definition ended the confusion resulting from different failure definitions that had been in use, and it did so accurately enough that it is probably not necessary to recalculate previously published results. Nevertheless, for the current pooled analysis of outcome in 4839 men with a 6.3-year median follow-up, other definitions of biochemical failure were superior as assessed by various quantitative measures of concordance of biochemical and ultimate clinical failure. An additional disadvantage of the ASTRO definition is the bias introduced by backdating failures, as well as the necessarily retrospective nature of its application. Some "current" definitions, but not those based on the PSA level rising above a fixed threshold, have significantly higher sensitivity and specificity, do not lead to biased estimations of biochemical disease-free survival, and are directly applicable during patient counseling. These are all issues that would play a role in replacing the ASTRO consensus definition.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2003
Multicenter StudyRectal dose-volume constraints in high-dose radiotherapy of localized prostate cancer.
To investigate the relationship between rectal bleeding and dosimetric-clinical parameters in patients receiving three-dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer. ⋯ The present article provides evidence for correlation between rectal DVH parameters and late rectal bleeding in patients treated with curative intent with 3D-CRT. To keep the rate of moderate/severe rectal bleeding below 5-10%, it seems advisable to limit V(50) to 60-65%, V(60) to 45-50%, and V70 to 25-30%.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2003
Multicenter StudyLong-term multi-institutional analysis of stage T1-T2 prostate cancer treated with radiotherapy in the PSA era.
To report the long-term outcome for patients with Stage T1-T2 adenocarcinoma of the prostate definitively irradiated in the prostate-specific antigen (PSA) era. ⋯ As follow-up lengthens and outcome data accumulate in the PSA era, we continue to evaluate the efficacy and durability of radiotherapy as definitive therapy for early-stage prostate cancer. Similar studies with higher doses and more contemporary techniques will be necessary to explore more fully the potential of this therapeutic modality.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2003
Unique role of proximal rectal dose in late rectal complications for patients with cervical cancer undergoing high-dose-rate intracavitary brachytherapy.
To investigate the correlation of the radiation dose to the upper rectum, proximal to the International Commission of Radiation Units and Measurements (ICRU) rectal point, with late rectal complications in patients treated with external beam radiotherapy (EBRT) and high-dose-rate (HDR) intracavitary brachytherapy (ICRT) for carcinoma of the uterine cervix. ⋯ Eighty-nine percent of our patients had a maximal rectal dose from ICRT at the proximal rectum instead of the ICRU rectal point. The difference between patients with and without late rectal complications was more prominent for the proximal rectal dose than for the ICRU rectal dose. It is important and useful to contrast the whole rectal wall up to the rectosigmoid junction and to calculate the dose at the proximal rectum for patients undergoing HDR ICRT.