International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2004
Influence of prostate volume on dosimetry results in real-time 125I seed implantation.
Achieving a minimal dose of 140 Gy to 90% of the prostate (D90) on postimplant dosimetry has been shown to yield improved biochemical control by 125I brachytherapy, and a D90 >180 Gy can be associated with increased long-term toxicity of seed implantation. Significant enlargement of the prostate on postimplant CT compared with the ultrasound (US) volume at implantation (CT/US ratio) has been associated with lower dose results, but other factors predicting for high or low doses are not well established. We determined whether the prostate size at implantation influenced the CT/US ratio results affecting postimplant dosimetry or predicted for D90 values <140 or >180 Gy in patients implanted with 125I in a community hospital setting. ⋯ Ninety percent of patients implanted by community-level practitioners using reference tables and real-time US-guided implantation achieved a D90 outcome of > or =140 Gy. Significant differences in dose outcomes <140 Gy and >180 Gy occurred related to PV. Those with prostates <25 cm3 had a 20% frequency of D90 <140 Gy, unrelated to excessive postimplant volume enlargement or insufficient activity per reference table, suggesting that the activity-to-volume recommendations may not allow for much variance in final seed position. Such seed displacement may contribute to lower doses, most commonly in small glands. One may consider increasing the activity implanted in small prostates, because a D90 >180 Gy occurred in only 7% of these cases. Patients with glands >40 cm3 were 25% likely to have a D90 result >180 Gy and were at only 3% risk of a D90 <140 Gy. These patients may benefit from intraoperative dosimetry or a reduction in implant activity.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2004
ReviewTargeted therapies for non-small-cell lung cancer: biology, rationale, and preclinical results from a radiation oncology perspective.
The epidermal growth factor receptor (EGFR) is overexpressed in the majority of non-small-cell lung cancers (NSCLCs). This presents an opportune target for new treatment strategies designed to selectively interfere with the cancer cell growth cycle. Recent investigations into the biology of the EGFR and its downstream signaling pathways have reminded us of the complexity of cancer cell communications from the cytoplasm to the nucleus. ⋯ Encouraging response rates with single-agent targeted therapy have been reported in heavily pretreated patients with advanced NSCLC. In addition, agents targeting the angiogenic pathway, which plays a key role in the regulation of angiogenesis, may play an important role in enhancing the efficacy of anti-EGFR agents. This article will focus on the biology, rationale, and preclinical studies with targeted anti-EGFR and antiangiogenic therapies for the management of NSCLC.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2004
Multicenter StudyRadical prostatectomy, external beam radiotherapy <72 Gy, external beam radiotherapy > or =72 Gy, permanent seed implantation, or combined seeds/external beam radiotherapy for stage T1-T2 prostate cancer.
To review the biochemical relapse-free survival (bRFS) rates after treatment with permanent seed implantation (PI), external beam radiotherapy (EBRT) <72 Gy (EBRT <72), EBRT > or =72 Gy (EBRT > or =72), combined seeds and EBRT (COMB), or radical prostatectomy (RP) for clinical Stage T1-T2 localized prostate cancer treated between 1990 and 1998. ⋯ The biochemical failure rates were similar among PI, high-dose (> or =72 Gy) EBRT, COMB, and RP for localized prostate cancer. The outcomes were significantly worse for low-dose (<72 Gy) EBRT.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2004
Effect of transurethral resection on urinary quality of life after permanent prostate brachytherapy.
To determine the effect of transurethral resection on urinary function after permanent prostate brachytherapy using a validated, patient-administered, quality-of-life (QOL) instrument. ⋯ TURP results in diminished urinary QOL after brachytherapy. However, patients who underwent preimplant TURP had urinary QOL approaching that of non-TURP brachytherapy patients. Significant urinary dysfunction was noted in approximately one-half of patients who underwent postimplant TURP (especially pre- and postimplant TURP). Because most patients with brachytherapy-related urinary obstruction will eventually spontaneously void, TURP should be approached with extreme caution and only after substantial time has transpired.