43 research outputs found

    Explorations in the derivation of word co-occurrence statistics

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    ABSTRACTRecent work has demonstrated that counts of which other words co-occur with a word of interest can reflect interesting properties of that word. We have studied aspects of this kind of methodology by systematically examining the effects of different combinations of parameters used in the preparation of co-occurrence statistics. Several psychologically relevant evaluation measures are used. We have found that successful performance on the evaluation tasks depends on the correct selection of parameters such as window size and distance metric.</jats:p

    Prospective comparison of rectal dose reduction during intracavitary brachytherapy for cervical cancer using three rectal retraction techniques.

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    PURPOSE: To compare three rectal retraction methods on dose to organs at risk, focusing on rectal dose, in cervix cancer patients treated with high-dose-rate intracavitary brachytherapy. METHODS AND MATERIALS: A prospective study was conducted on patients with cervical carcinoma treated with chemoradiotherapy, including external beam radiation and four fractions of high-dose-rate intracavitary brachytherapy prescribed to Point A using a ring and tandem applicator under conscious sedation. Rectal retraction methods included: a rectal retractor blade (RR), vaginal gauze packing (VP), and a tandem Foley balloon (FB). All three methods were used in all patients. The RR was used first, and the following applications were randomly assigned to VP or FB. CT planning was used to calculate D2cc for rectum, sigmoid, small bowel, and bladder. The Wilcoxon signed rank test was used to determine if the median dose differences between methods were statistically significant. RESULTS: In these 11 patients, median dose (min, max) in cGy to the rectum using RR, FB, and VP was 131 (102, 165), 199 (124, 243), and 218 (149, 299), respectively. The RR demonstrated lower median intrapatient doses to rectum compared with FB and VP (-55 cGy; p = 0.014 and -76 cGy; p = 0.004, respectively). The RR also resulted in lower sigmoid doses. No differences in dose were observed between the VP and FB methods. CONCLUSION: The rectal retractor significantly reduced the dose to rectum and sigmoid compared with FP and VP. In patients treated under conscious sedation, the RR method provides the best rectal sparing. There were no significant differences in dose observed between the FB and VP techniques

    Phase III trial to evaluate the efficacy of maintaining hemoglobin levels above 12.0 g/dL with erythropoietin vs above 10.0 g/dL without erythropoietin in anemic patients receiving concurrent radiation and cisplatin for cervical cancer.

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    Contains fulltext : 71497.pdf (publisher's version ) (Closed access)PURPOSE: To determine whether maintaining HGB levels > or = 12.0 g/dL with recombinant human erythropoietin (R-HUEPO) compared to "standard" treatment (transfusion for HGB 14.0 g/dL. Endpoints were PFS, OS and LC. Platinum-DNA adducts were quantified using immunocytochemistry assay in buccal cells. RESULTS: Between 08/01 and 09/03, 109 of 114 patients accrued were eligible. Fifty-two received CT/RT and 57 CT/RT+R-HUEPO. The study closed prematurely, with less than 25% of the planned accrual, due to potential concerns for thromboembolic event (TE) with R-HUEPO. Median follow-up was 37 months (range 9.8-50.4 months). PFS and OS at 3 years should be 65% and 75% for CT/RT and 58% and 61% for CT/RT+R-HUEPO, respectively. TE occurred in 4/52 receiving CT/RT and 11/57 with CT/RT+R-HUEPO, not all considered treatment related. No deaths occurred from TE. High-platinum adducts were associated with inferior PFS and LC. CONCLUSION: TE is common in cervical cancer patients receiving CT/RT. Difference in TE rate between the two treatments was not statistically significant. The impact of maintaining HGB level > 12.0 g/dL on PFS, OS and LC remains undetermined
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