International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2009
Multicenter StudyEvaluation of dosimetric parameters and disease response after 125 iodine transperineal brachytherapy for low- and intermediate-risk prostate cancer.
To analyze dosimetric outcomes after permanent brachytherapy for men with low-risk and "low-tier" intermediate-risk prostate cancer and explore the relationship between the traditional dosimetric values, V100 (volume of prostate receiving 100% of the prescribed dose) and D90 (minimum dose to 90% of the prostate), and risk of biochemical failure. ⋯ In contrast to some previous studies, dosimetric outcomes did not correlate with biochemical recurrence in the first 1,006 patients treated with 125I prostate brachytherapy at the British Columbia Cancer Agency. Despite a median D90 of only 105% of MPD, our bNED rates are indistinguishable from series that reported higher D90 values.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2009
Sensitivity analysis of parameters in linear-quadratic radiobiologic modeling.
Radiobiologic modeling is increasingly used to estimate the effects of altered treatment plans, especially for dose escalation. The present article shows how much the linear-quadratic (LQ) (calculated biologically equivalent dose [BED] varies when individual parameters of the LQ formula are varied by +/-20% and by 1%. ⋯ Robustness occurs similar to that of equivalent uniform dose (EUD), for the same reasons. Total dose, dose per fraction, and dose-rate cause their major effects, as well known.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2009
Randomized Controlled Trial Multicenter StudyMathematical model for evaluating incidence of acute rectal toxicity during conventional or hypofractionated radiotherapy courses for prostate cancer.
To describe the radiation-induced acute rectal toxicity (ART) using a modified Lyman-Kutcher-Burman normal tissue complication probability model and parameters set, taking into account the overall treatment time. ⋯ The optimized modified Lyman-Kutcher-Burman normal tissue complication probability model allowed us to describe the ART data from conventional and hypofractionated regimens, using the dose-volume histograms and overall treatment time. This model could prove useful in designing hypofractionation schedules to reduce the incidence of ART.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2009
Sensorineural hearing loss after treatment of nasopharyngeal carcinoma: a longitudinal analysis.
To analyze the effects of radiotherapy (RT) and chemotherapy in relation to sensorineural hearing loss (SNHL) after contemporary treatment of nasopharyngeal carcinoma. ⋯ The results of our study have shown that high-frequency SNHL is significantly related to the mean cochlea dose and the concurrent cisplatin dose. A mean dose constraint of 47 Gy to the cochlea is recommended to minimize SNHL after chemoradiotherapy.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2009
Comparative StudyUse of the concept of equivalent biologically effective dose (BED) to quantify the contribution of hyperthermia to local tumor control in radiohyperthermia cervical cancer trials, and comparison with radiochemotherapy results.
To express the magnitude of contribution of hyperthermia to local tumor control in radiohyperthermia (RT/HT) cervical cancer trials, in terms of the radiation-equivalent biologically effective dose (BED) and to explore the potential of the combined modalities in the treatment of this neoplasm. ⋯ The most significant improvements in TCP, which may result from the combination of RT/CT/HT for locally advanced cervical carcinomas, are likely to be limited only to those patients with tumors of relatively low-intermediate radiosensitivity.