Model-based analysis of dispersion curves using chirplets.

Time-frequency representations, like the spectrogram or the scalogram, are widely used to characterize dispersive waves. The resulting energy distributions, however, suffer from the uncertainty principle, which complicates the allocation of energy to individual propagation modes (especially when the dispersion curves of these modes are close to each other in the time-frequency domain). This research applies the chirplet as a tool to analyze dispersive wave signals based on a dispersion model.

Spinal growth after irradiation for Wilm's tumour.

Between 1960 and 1983, 82 children were treated for Wilm's tumour at our hospital. The secondary effects and changes in the skeleton have been assessed. Radiotherapy was found to cause growth disturbances and osteochondrosis of variable degree, but not osteonecrosis.

[Vertebral changes after irradiation for Wilms' tumor in early childhood. A retrospective interdisciplinary long-term study of 82 children].

82 children with nephroblastomas, who had therapy between 1960 and 1983, underwent continuous follow-up examinations until 1988. 79 children who survived had been treated with nephrectomy followed by radiation therapy (n = 72) and chemotherapy (n = 72). 64 of these patients had a combination of both post-surgical treatments.

[Results of local radiotherapy and modified total-brain irradiation in astrocytoma].

A retrospective evaluation was made on the results of primary or postoperative radiotherapy in 162 patients with grade I to IV astrocytomas. The greatest part of the overall group was built by 113 patients suffering from glioblastoma multiforme. For the survival analysis, the prognostic importance of the following factors was investigated: sex, age, surgery, radicality of surgery, grading according to Kernohan, tumorous lesions in central structures, and target volume of radiotherapy.

[Radiotherapy of locally recurring colorectal tumors. Prognostic factors, follow-up diagnosis and results].

From 1979 through April, 1985, 74 patients were treated by percutaneous irradiation for local recurrences of colorectal carcinomas. The treatment consisted of a contralateral irradiation up to a dose of 40 Gy and a small-volume boost up to 60 to 66 Gy. In case of progressive remote metastases, the treatment was finished at 50 Gy.