International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2002
(IN)-efficacy of salvage radiotherapy for rising PSA or clinically isolated local recurrence after radical prostatectomy.
To determine the efficacy of external beam radiotherapy (RT) as salvage treatment for prostate-specific antigen (PSA) failure or local recurrence after radical prostatectomy. ⋯ The efficacy of salvage RT for PSA failure or local recurrence after RT was limited, reflected by very low relapse-free rates. Salvage RT appeared more efficacious for patients with a delayed PSA rise than for those with either persistently detectable postoperative PSA levels or clinically palpable local recurrence. Other strategies such as a combination of salvage RT and hormonal therapy need to be explored.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2002
Practical application of biochemical failure definitions: what to do and when to do it.
The posttreatment prostate-specific antigen (PSA) profile can often be difficult to interpret after external beam radiotherapy for prostate cancer. We performed an extensive analysis of post-radiotherapy PSA measurements to determine the clinical significance of biochemical failure (BF) and the correlation of BF with clinical failure (CF) and cause-specific death (CSD). ⋯ Once the post-radiotherapy PSA profile reaches >or=3 ng/ml above the nadir, there is a high risk of clinical failure within a relatively short time period, for which treatment intervention may be considered, regardless of pretreatment characteristics. After a nadir >or=1.0 ng/ml or three consecutive rises, some patients (especially with low-risk pretreatment characteristics) may be considered for further PSA observation before treatment intervention.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2002
Intrafraction prostate motion during IMRT for prostate cancer.
Although the interfraction motion of the prostate has been previously studied through the use of fiducial markers, CT scans, and ultrasound-based systems, intrafraction motion is not well documented. In this report, the B-mode, Acquisition, and Targeting (BAT) ultrasound system was used to measure intrafraction prostate motion during 200 intensity-modulated radiotherapy (IMRT) sessions for prostate cancer. ⋯ Using an ultrasound-based system, intrafraction prostate motion occurred predominantly in the anterior and superior directions, but was clinically insignificant. Intrafraction motion was much smaller than interfraction motion, and the two types of movement did not correlate.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2002
Effect of prostatic edema on CT-based postimplant dosimetry.
To investigate the magnitude of edema after prostate brachytherapy and its effect on the CT-based postimplant dosimetry based on the sequential CT scans using dose-volume histograms, dose conformity, and homogeneity indices in patients with prostate cancer. ⋯ The decrease in prostate volume from Day 1 to Day 28 after the implant markedly improved the prescription dose covering the prostate from 77% to 85%. Day 28 prostate volumes were still about 10% larger than the preimplant CT volumes for the 25 cases evaluated. Postimplant dosimetry using dose conformity and homogeneity indices is dependent on the timing of CT studies, as a result of changing prostate volumes from edema.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2002
Data from a professional society placement service as a measure of the employment market for radiation oncologists.
To aid in understanding the employment market for radiation oncologists, we present annual data for 1991 to 2000 from the American College of Radiology's placement service, the Professional Bureau. This data series is twice as long as any previously available. Secondarily, we compare these data with other data on the employment market. ⋯ The employment market for radiation oncologists weakened in the first half of the 1990s, as had been widely reported; we present the first systematic data showing this. Data from a professional society placement service provide useful and inexpensive information on the employment market.