Biomedical subjects

P Duffner

Publications and source records attributed to P Duffner.

5 recordsLinked to original sources

PubMed2000

Low-stage medulloblastoma: final analysis of trial comparing standard-dose with reduced-dose neuraxis irradiation.

PURPOSE: To evaluate prospectively the effects on survival, relapse-free survival, and patterns of relapse of reduced-dose (23.4 Gy in 13 fractions) compared with standard-dose (36 Gy in 20 fractions) neuraxis irradiation in patients 3 to 21 years of age with low-stage medulloblastoma, minimal postoperative residual disease, and no evidence of neuraxis disease. PATIENTS AND METHODS: The Pediatric Oncology Group and Children's Cancer Group randomized 126 patients to the study. All patients received posterior fossa irradiation to a total dose of 54 Gy in addition to the neuraxis treatment. Patients were staged postoperatively with contrast-enhanced cranial computed tomography, myelography, and CSF cytology. Of the registered patients, 38 were ineligible. RESULTS: The planned interim analysis that resulted in closure of the protocol showed that patients randomized to the reduced neuraxis treatment had increased frequency of relapse. In the final analysis, eligible patients receiving standard-dose neuraxis irradiation had 67% event-free survival (EFS) at 5 years (SE = 7.4%), whereas eligible patients receiving reduced-dose neuraxis irradiation had 52% event-free survival at 5 years (SE = 7.7%) (P =.080). At 8 years, the respective EFS proportions were also 67% (SE = 8.8%) and 52% (SE = 11%) (P =.141). These data confirm the original one-sided conclusions but suggest that differences are less marked with time. CONCLUSION: Reduced-dose neuraxis irradiation (23.4 Gy) is associated with increased risk of early relapse, early isolated neuraxis relapse, and lower 5-year EFS and overall survival than standard irradiation (36 Gy). The 5-year EFS for patients receiving standard-dose irradiation is suboptimal, and improved techniques and/or therapies are needed to improve ultimate outcome. Chemotherapy may contribute to this improvement.

Adolescent↗

PubMed1998

Acquired oral reading vocabulary following the onset of amnesia in childhood.

While the neuropsychological literature includes few cases of child-onset amnesia, 2 previous case studies suggest that these patients may be able to learn new information of a semantic or academic nature. The previous studies were, in large part, based on neuropsychological testing performed during adulthood and a retrospective review of academic achievement test scores during childhood. We present patient A.C., who acquired severe anterograde amnesia at age 10 years but demonstrated average levels of performance on tests of reading, spelling and arithmetic upon examination at age 19 years. Episodic and semantic memory test scores were severely impaired, but near normal performances were found on tests of implicit and procedural memory. In a prospective study, A.C. learned to read new irregular and pseudowords and retained this learning over a 1-month period, similar to the performance of age-matched controls. This demonstration of postmorbid, acquired oral reading vocabulary supports a previous conclusion that oral reading can progress in childhood following the onset of severe anterograde amnesia. The data also suggest that this new learning probably reflects nondeclarative memory processes rather than preservation of semantic memory, as was proposed in an earlier case study.

Amnesia↗

PubMed1996

Results of a prospective randomized trial comparing standard dose neuraxis irradiation (3,600 cGy/20) with reduced neuraxis irradiation (2,340 cGy/13) in patients with low-stage medulloblastoma. A Combined Children's Cancer Group-Pediatric Oncology Group Study.

PURPOSE: To determine in a prospective randomized trial the effect on survival, progression-free survival, and patterns of relapse of a decrease in the neuraxis radiation dose from 3,600 cGy in 20 fractions to 2,340 cGy in 13 fractions in patients with newly diagnosed medulloblastoma between 3 and 21 years of age with low T stage (T1, T2 and T3A), minimal postoperative residual tumor, and no evidence of dissemination (M0). METHODS AND MATERIALS: Between June 1986 and November 1990, the Children's Cancer Group and the Pediatric Oncology Group randomized 126 patients in a two-arm study comparing the two different doses of neuraxis irradiation. In both arms, the posterior fossa received 5,400 cGy in 30 fractions. All patients were staged with myelography, postoperative lumbar cerebrospinal fluid cytology, and postoperative contrast-enhanced cranial computerized tomography to ensure no evidence of dissemination and no more than 1.5 cm3 residual tumor volume. Overall survival, progression-free survival, and patterns of recurrence were carefully monitored. Prospective endocrine and psychometric studies were performed to determine the benefit of decreasing the neuraxis radiation dose. RESULTS: Following an interim analysis at a median time on study of 16 months, the study was closed, since a statistically significant increase was observed in the number of all relapses as well as isolated neuraxis relapses in patients randomized to the lower dose of neuraxis radiation. CONCLUSIONS: In patients with newly diagnosed medulloblastoma considered to have a good prognosis on the basis of low T stage, minimal residual tumor after at least subtotal resection, and no evidence of dissemination after thorough evaluation, there is an increased risk of early relapse associated with lowering the dose of neuraxis radiation from 3,600 cGy in 20 fractions to 2,340 cGy in 13 fractions.

Adolescent↗

PubMed1989

Immunochromatographic measurement of phenobarbital in whole blood with a non-instrumented assay.

We tested the precision and accuracy of the AccuLevel Phenobarbital Test, which reports whole-blood (fingerstick) results in plasma equivalent values, and compared these values with plasma results obtained using established methods. We conclude that the assay is precise, reliable, accurate for single tests, and is appropriate for use in offices, outpatient settings, and emergency rooms.

Chromatography↗

PubMed1976

Multicore disease in twins.

Multicore disease in identical twin boys presented in infancy as generalized weakness and torticollis. Motor milestones such as sitting, standing, and running were delayed, although by the age of 6 years marked improvement in muscle strength had occurred. Serum enzymes were normal. Muscle biopsy revealed multifocal areas of decreased oxidative enzyme activity. Ultrastructurally, these areas were characterized by myofilament disruption and Z-band streaming.

Child↗