• The Journal of Korean Society for Radiation Therapy
• /
• v.34
• /
• pp.73-82
• /
• 2022

Purpose: The purpose of this study is to evaluate the effectiveness of reducing the absorbed dose to the ovaries and the quality of the CBCT image when using the Halcyon^TM Fast kV CBCT of cervical cancer patients of child-bearing age who performed ovarian transposition Materials and Methods : Contouring of the cervix and ovaries required for measurement was performed on the computed tomography images of the human phantom (Alderson Rando Phantom, USA), and three Optically Stimulated Luminescence Dosimeter(OSLD) were attached to the selected organ cross-section, respectively. In order to measure the absorbed dose to the cervix and ovaries in the Truebeam^TM pelvis mode (Hereinafter referred to as TP), The Halcyon^TM Pelvis mode (Hereinafter referred to as HP) and The Halcyon^TM Pelvis Fast mode (Hereinafter referred to as HPF), An image was taken with a scan range of 17.5 cm and also taken an image that reduced the Scan range to 12.5cm. A total of 10 cumulative doses were summed, It was replaced with a value of 23 Fx, the number of cervical cancer treatments, and compared In additon, uniformity, low contrast visibility, spatial resolution, and geometric distortion were compared and analyzed using Catphan 504 phantom to compare CBCT image quality between equipment. Each factor was repeatedly measured three times, and the average value was obtained by analysing with the Doselab (Mobius Medical Systems, LP. Versions: 6.8) program. Results: As a result of measuring absorbed dose by CBCT with OSLD, TP and HP did not obtain significant results under the same conditions. The mode showing the greatest reduction value was HPF versus TP. In HPF, the absorbed dose was reduced by 39.8% in the cervix and 19.8% in the ovary compared to the TP in the scan range of 17.5 cm. the scan range was reduced to 12.5 cm, absorbed dose was reduced by 34.2% in the cervix and 50.5% in the ovary. In addition, result of evaluating the quality of the image used in the above experiment, it complied with the equipment manufacturer's standards with Geometric Distortion within 1mm (SBRT standard), Uniformity HU, LCV within 2.0%, Spatial Resolution more than 3 lp/mm. Conclusion: According to the results of this experiment, Halcyon^TM can select more various conditions than Truebeam^TM in treatment of fertility woman who have undergone ovarian Transposition , because it is important to reduce the radiation dose by CBCT during radiation therapy. So finally we recommend Halcyon^TM Fast kV CBCT which maintains image quality even at low mAs. However, it is consider that the additional exposure to low doses can be reduced by controlling the imaging range for patients who have undergone ovarian transposition in other treatment machines.

• Applied Biological Chemistry
• /
• v.17 no.3
• /
• pp.193-218
• /
• 1974

These studies were carried out for the elucidation of liming effect on the growth of rice seedlings and the chemical characteristics of an acid sulphate paddy that shows not only extremely high acidity of soil but also poor growth of rice plants, consequently low yield. Thus the liming effect on the changes of acidity, oxidation-reduction potential, and the contents of iron, aluminium, sulphate, and phosphorus fractions in the soil was investigated under the waterlogging and drying condition. The reclaimable or inhibitory effect of phosphorus, iron and aluminium on the growth of rice seedlings was also investigated under liming. The results are summarized as follows: 1. After liming, the pH of the acid sulphate subsoil decreased again on drying. 2. The oxidation-reduction potential reached a minimum after 5 days of flooding and greatly decreased on liming but increased after drying. 3. The contents of ferrous iron soluble in water-and Morgan's solution reached a maximum after 15 days of flooding and only the content of water soluble ferrous iron was greatly decreased. 4. The content of aluminium soluble in water-and Morgan's solution decreased by flooding and liming, and showed a tendency to increase on drying. 5. In the limed acid sulphate soil, the content of water soluble calcium showed a highly significant negative correlation with the content of sulphate and liming decreased sulphate content in the soil. 6. The contents of total phosphorus was 496.3 ppm in the acid sulphate topsoil and 387.5 ppm in the subsoil. The content of each phosphorus fraction was in the order of Fe-P>Occ. Fe-P>Ca-P>Occ. Al-P>Al-P and Fe-P content in the soil was the highest fraction among them. 7. Lime application increased greatly Ca-P and Al-P, and Occ. Fe-P and Occ. Al-P only slightly, but decreased Fe-P differently in each soil. 8. Effect of phosphorus on the dry matter yield of rice seedlings was great. The optimum amount of phosphorus to produce maximum dry matter yield of rice seedlings appeared to be 6.8% of maximum absorption (absorption coefficient) without liming and 10.0% with liming. 9. In rice seedlings liming increased the content and uptake of calcium and silica but decreased those of iron and aluminium. Phosphorus application increased the content and uptake of phosphorus and decreased iron while the application of iron and aluminium increased their contents and uptake but decreased those of phosphorus. 10. Liming greatly alleviated such toxicity of iron and aluminium. 11. When phosphorus was applied, the dry matter yield of rice seedlings showed highly significant positive correlations with uptake of phosphorus, calcium and silica each. When iron and aluminium were applied, dry matter yields indicated significant positive correlations with the contents or uptake of calcium and silica each, but significant negative correlations with the content or uptake of iron and aluminium. 12. Under the application of phosphorus and lime, dry matter yields showed significant positive correlations with pH and Morgan's extractable calcium each of the soil samples after harvest. Under the application of lime, iron and aluminium, dry matter yields showed significant positive correlations with pH, calcium and silica each, but negative correlations with iron and aluminium contents each of the soil samples after harvest.

• The Korean Journal of Physiology
• /
• v.18 no.2
• /
• pp.151-162
• /
• 1984

The mechanism of the contractile response of longitudial muscle of rabbit ileum to substance P (SP) has been investigated. The contractions in rabbit ileum under various conditions were recorded isometrically The following results were obtained. 1) The contractions by SP increased according to concentrations. SP·induced contraction was not sustained but faded rapidly at $10^{-7}M$. The response to the commutative addition of SP was decreased in comparison to the response to separate administration of each concentration . 2) The response to $10^{-8}M$ SP after 5 min application cf $10^{-7}M$ SP was increased with increasing the time interval between the administration of $10^{-7}$ and $10^{-8}M$ SP. 3) The treatment of rabbit ileum by $10^{-7}M$ SP for 5 min didn't decrease the response to $10^{-6}M$ acetylcholine. 4) $10^{-6}M$ atropine had no effect of the contractile response to $10^{-7}M$ SP. The response to $10^{-7}M$ SP was normal or subnormal in the presence of 3 mM tetraethylammonium(TEA). 5) 100k solution, $10^{-4}M$ ouabain, and Na-free solution inhibited the response to $10^{-8}M$ SP and 3 mM TEA completely, and to $10^{-7}M$ SP incompletely. 3 mM TEA induced a considerable contraction in K-free solution, but $10^{-8}M$ SP didn't induce the contraction. $10^{-6}M$ norepinephrine decreased the contractile responses to SP and TEA. 6) The contractile response to $10^{-7}M$ SP was dependent on the extracellular $Ca^{2+}$ concentrations to 1.8 mM. 7) The contractile response to $10^{-7}M$ SP remained 15% of the maximal response after bathing the ileum in a Ca-free solution for 2.5 min. 8) The responsiveness to SP was completely lost within 10 min of bathing in Ca-free solution, but was restored by the exposure to $Ca^{2+}$. The restorative effect of $Ca^{2+}$ depended on the concentration of $Ca^{2+}$, and on time for which the tissue exposed to this $Ca^{2+}$ concentration. These results suggest that there are two mechanisms of the action by which the low concentrations of substance P causes the contraction of intestinal smooth muscle: the reduction of K conductance and a mechanism dependent on the extracellular $Ca^{2+}$, and that high concentration of SP may elicit a contraction by releasing $Ca^{2+}$ from an intracellular store, which is not as sensitive to removal of extracellular $Ca^{2+}$ or as easily accessible to EGTA as the extracellular space of the muscle. The location of this store is not known; it may be associated with the internal side of the cell membrane.