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Vincent C Arena

Publications and source records attributed to Vincent C Arena.

2 recordsLinked to original sources

Model validation software for classification models using repeated partitioning: MVREP.

The process of assessing the prediction ability of a computational model is called model validation. For models predicting a categorical response, the prediction ability is usually quantified by prediction measures such as sensitivity, specificity, and accuracy. This paper presents a software Model Validation using Repeated Partitioning (MVREP) that implements a computer-intensive, nonparametric approach to model validation, which we call the re-partitioning method. MVREP, developed using the SAS Macro language, repeats the process of randomly partitioning a dataset and subsequently performing standard model validation procedures, such as cross-validation, a large number of times and generates the empirical sampling distributions of prediction measures. The means of the sampling distributions serve as the point estimates of prediction measures of the model. The variances of the sampling distributions provide a direct assessment of variability for the point estimates of prediction measures. An example is presented using a mouse developmental toxicity chemical dataset to illustrate how the software can be used for the assessment of structure-activity relationships models.

Animals↗

The Brain Tumor Cooperative Group NIH Trial 87-01: a randomized comparison of surgery, external radiotherapy, and carmustine versus surgery, interstitial radiotherapy boost, external radiation therapy, and carmustine.

OBJECTIVE: The objective of the Brain Tumor Cooperative Group NIH Trial 87-01 trial was to investigate the effect of additional implanted radiation therapy in newly diagnosed patients with pathologically confirmed malignant gliomas. METHODS: The study involved a randomized comparison of surgery, external beam radiotherapy, and carmustine (BCNU) versus surgery, external beam therapy, interstitial radiotherapy boost, and BCNU in newly diagnosed malignant gliomas. (125)I was chosen as best suited for this effort because it allowed preimplantation planning and postimplantation quality assurance review. Two hundred ninety-nine patients met the eligibility criteria and were randomized into the two arms of the study between December 1987 and April 1994. Follow-up continued for an additional 3 years. Twenty-nine patients were identified as having committed protocol violations and were excluded, resulting in 270 subjects in the Valid Study Group. One hundred thirty-seven patients received external beam radiation and BCNU, and 133 underwent the (125)I implantation plus external beam radiation and BCNU therapy. RESULTS: The overall median survival for the Valid Study Group was 64.3 weeks. The median survival for patients receiving additional therapy of (125)I was 68.1 weeks, and median survival for those receiving only external beam radiation and BCNU was 58.8 weeks. The cumulative proportion surviving between the two treatment groups was not statistically significantly different (log-rank test, P = 0.101). As in other studies in the literature, age, Karnofsky score, and pathology were predictors of mortality. Additional analyses incorporating an adjustment for these prognostic variables, either in a stratified analysis or Cox proportional hazards model, did not result in statistically significant differences in the cumulative proportion of patients surviving between the two treatment groups. CONCLUSION: We conclude that there is no long-term survival advantage of increased radiation dose with (125)I seeds in newly diagnosed glioma patients.

Antineoplastic Agents, Alkylating↗