PubMed Health⌕ Search

Biomedical subjects

M Drzymala

Publications and source records attributed to M Drzymala.

3 recordsLinked to original sources
PubMed2004

Virtual simulation in palliative lung radiotherapy.

AIMS: To study the accuracy of tumour-volume localisation in a comparison of conventional and virtual simulation for palliative lung radiotherapy. To assess if three-dimensional tumour outlining is necessary for the virtual simulation process. MATERIALS AND METHODS: Ten consecutive patients with non-small cell lung cancer underwent target localisation for palliative lung radiotherapy using conventional and virtual simulation. The treatment fields were initially marked with a conventional simulator using fluoroscopy, plain X-ray film and available diagnostic imaging. Each patient then had a computed tomography (CT), and these simulated treatment fields were reproduced within the virtual simulation planning system. Two clinicians then independently defined treatment fields using virtual simulation alone. The virtual simulation was achieved without outlining the tumour in three dimensions. The coverage of an 'ideal' CT-defined planning-target volume (PTV) was then calculated for each of the virtually and conventionally simulated fields. In addition, the amount of irradiated normal lung was measured using dose-volume histograms (DVH). Field sizes and differences in tumour volume coverage were compared. RESULTS: There was significantly greater tumour volume coverage using virtual simulation compared with conventional simulation (P < 0.03). This advantage was more pronounced in tumours that were larger and those that were closer to the patient's midline. There was no statistically significant difference in the volume of uninvolved lung irradiated between the two methods. CONCLUSION: In this small sample of patients, we have demonstrated improved tumour volume coverage using virtual simulation, without increasing the volume of uninvolved lung treated. A simple but consistent method of virtual simulation for this patient group is offered as an alternative to both PTV-defined CT simulation and fluoroscopy-based conventional simulation.

Carcinoma, Non-Small-Cell Lung↗
PubMed1987

Regulation of accessory cell function by retinoids in murine immune responses.

This study examines the effects of in-vivo immune regulation by vitamin A acetate (VAA) and 13-cis-retinoic acid (13-CRA) on in-vitro accessory cell function. Mice were fed a control diet, or diet containing VAA or 13-CRA, and monitored by body weight gains and diet consumptions at weekly intervals. At 4, 7 and 12 weeks mice were killed, differential blood counts performed and accessory cells isolated from lymphomedullary tissues. Histology confirmed that the chief feature of the lymphomedullary organs of the VAA-fed animals was an expansion of the splenic marginal zone and the paracortical region of the lymph nodes. There was an increase in the number of accessory cells present, and this included both dendritic cells and macrophages. The accessory cell function of these cells was also increased, as evidenced by both alloproliferative and allocytotoxic responses in vitro. In 13-CRA-fed animals the effects were similar to those seen with VAA, but were less pronounced. We suggest that the primary effects of these compounds on in-vivo immunoregulation could be due to their promotion of accessory cell function.

Animals↗