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Biomedical subjects

C L Hutchinson

Publications and source records attributed to C L Hutchinson.

3 recordsLinked to original sources

The National Cancer Data Base report on patterns of childhood cancers in the United States.

BACKGROUND: Patterns of and progress against childhood cancer have been reported on multi-institution, regional, national, and international bases by several sources in the past. These sources have included clinical cooperative group trials and population-based registries. In general, the population-based surveys have excluded brain tumors of either benign or uncertain behavior. The authors of this article investigated the patterns of data reported for the period 1985-1993, motivated by their interest in assessing the potential of National Cancer Data Base (NCDB) data to 1) facilitate individual institution review and 2) cover institutions that are not members of the Pediatric Oncology Group or the Children's Cancer Group, which are both national clinical cooperative groups. METHODS: Six annual calls for data, starting with a call for 1985 and 1988 cases, were issued to approximately 2100 hospitals with cancer programs (1340 programs approved by the Commission on Cancer of the American College of Surgeons and 760 other programs). The baseline data items of the NCDB included patient demography, tumor characteristics, initial treatment, and follow-up. The data for each patient were coded in the traditional manner by trained cancer registrars before being transmitted to the NCDB in standard format. RESULTS: In the most recent year for which data were reported, the NCDB included 42% of all estimated U.S. childhood cancers. The cases were reported by institutions that were members of the Pediatric Oncology Group and the Children's Cancer Group as well as nonmember institutions. The distribution of diagnostic groups reported to the NCDB was generally similar to that reported to SEER, except for lymphomas and brain cancer (the NCDB series included benign as well as malignant brain tumors). The distribution of diagnostic groups reported to the NCDB did not change over the 9-year reporting period (1985-1993). With regard to ethnicity, the most varied distribution of diagnostic groups was found among African American patients. For many types of cancer, the survival of those patients reported to the NCDB was similar to that of patients included in the SEER population-based series. These cancers included Wilms' tumor (NCDB 89% vs. SEER 88%), non-Hodgkin's lymphoma (NCDB 74% vs. SEER 70%), soft tissue sarcomas (NCDB rhabdomyosarcomas 70% and sarcomas 79% vs. SEER soft tissue sarcomas 71%), and neuroblastoma (NCDB 58% vs. SEER 57%). CONCLUSIONS: The authors concluded that the number of brain tumors of benign and uncertain behavior being diagnosed were significant enough in number that they should be included in regional and national cancer registries that report data for clinical purposes. They further concluded that for reasons of data inclusion and institutional coverage, the NCDB will be an important data base for pediatric cancers that will warrant increased use by pediatric investigators.

Adolescent↗

Fluorescence and absorption contrast mechanisms for biomedical optical imaging using frequency-domain techniques.

The ability to optically image or detect diseased tissue volumes located deep within tissues depends upon the degree of contrast provided by differences in local optical properties. In this report, we show that the exogenous contrast offered by fluorescent compounds is superior to that provided by nonfluorescing, light-absorbing compounds when time-dependent measurements are employed. In addition, we show that the induced contrast is not only moderated by the preferential uptake of fluorescent agents into diseased tissue volumes of interest but also by the fluorescent optical properties and the fluorescence dynamics in the specific tissue volume. Using tissue phantom studies, we demonstrated experimentally that near-infrared-absorbing and fluorescent dyes such as indocyanine green can provide detection of diseased tissue volumes from fluorescence measurements made at the periphery of tissue when there is perfect, 100-fold and 10-fold partitioning in diseased tissues over that in surrounding normal tissues. Experimental results of common laser dyes show the contrast is also mediated by the quantum yield and lifetime parameters that may be dependent upon the local tissue environment.

Diagnosis↗

Fluorescence lifetime-based sensing in tissues: a computational study.

We have numerically solved the photon diffusion equation to predict the distribution of light in a tissue model system with a uniform concentration of fluorophore. Our results show that time-dependent measurements of light propagation can be used to monitor the fluorescent lifetimes of a uniformly distributed fluorophore in tissues. With proper referencing, frequency-domain measurements of phase-shift, theta, may allow quantitation of fluorescent lifetimes, tau, independent of changes in the local absorption and scattering properties. These results point to a new approach for noninvasive diagnostic monitoring through quantitation of fluorescent lifetime, tau, when the lifetime of the fluorophore is comparable with photon migration times.

Biophysical Phenomena↗