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- Ekberg, Lars, et al.
(författare)
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What margins should be added to the clinical target volume in radiotherapy treatment planning for lung cancer?
- 1988
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Ingår i: Radiotherapy and Oncology. - 1879-0887. ; 48:1, s. 71-77
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The planning target volume in radiotherapy treatment planning takes into account both movements of the clinical target volume (CTV) and set-up deviations. MATERIALS AND METHODS: A group of patients who received radiotherapy for lung cancer were studied. In order to measure the CTV movements due to respiration and other internal organ motions, fluoroscopy was performed for 20 patients. To study the accuracy and reproducibility of patient and beam set-up, 553 electronic portal images from 20 patients were evaluated. Discrepancies between planned and actual field positions were measured and the systematic and random errors were identified. The combined effect of these geometrical variations was evaluated. RESULTS: The average CTV movement with quiet respiration was about 2.4 mm in the medio-lateral and dorso-ventral directions. Movement in the cranio-caudal direction was on average 3.9 mm with a range of 0-12 mm. The systematic set-up errors were on average 2.0 mm in the transversal plane and 3.0 mm in the cranio-caudal direction. The random errors can be described by their standard deviations of 3.2 and 2.6 mm. In this study, the combined effect of the two parameters (CTV movement and set-up deviations) varied between 7.5 and 10.3 mm in different anatomical directions. CONCLUSIONS: In our daily clinical routine, we use a margin of 11 mm in the transversal plane and 15 mm cranially and caudally, also taking into account other unquantified variations and uncertainties.
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| 5. |
- Ljung, R., et al.
(författare)
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Platelet-associated IgG in childhood idiopathic thrombocytopenic purpura : measurements on intact and solubilized platelets and after gammaglobulin treatment
- 1986
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Ingår i: Scandinavian Journal of Haematology. - : Wiley. - 0036-553X. ; 36:4, s. 402-407
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Tidskriftsartikel (refereegranskat)abstract
- An immunoradiometric assay was developed for determining platelet-associated IgG (PAIgG) both on intact and solubilized platelets. In 20 healthy subjects PAIgG was 0.28 ± 0.20 ng/106 platelets and 2.2 ± 1.1 ng/106 platelets on intact and on solubilized platelets, respectively. 13 children with acute ITP all had increased concentrations of PAIgG, but no correlation was found between the severity of thrombocytopenia and PAIgG concentrations, either on intact or on solubilized platelets. Neither was there any correlation of the increase in PAIgG between intact and solubilized preparations. 3 out of 4 children who received high-dose i.v. gammaglobulin showed a concomitant normalization of the platelet count and of the PAIgG concentration both on intact and lyzed platelets. The remaining child did not respond to gammaglobulin and continued to have abnormal PAIgG.
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