ABSTRACT
Objective:To verify the dose of static and dynamic intensity modulated radiotherapy (IMRT) through 2-dimension ionization chamber matrix after external electrically-driven multi-leaf collimator (MLC) was installed in KB1800 medical linear accelerator. Methods: 40 patients who need receive IMRT were divided into static IMRT group (20cases) and dynamic IMRT group (20cases) as the random number table. The ionization chamber was applied to implement scale dose, and solid water and 2-D ionization chamber matrix was applied to verify dose. Besides, the feasibility of static and dynamic IMRT were compared and researched.Results: The verification results of plane dosage of static IMRT plan and dynamic IMRT plan showed that the passing rates both of them were above 90.0%, and the verification of intensity modulated dosimetry of medical electric linear accelerator KB1800 with external electric MLC was consistent with standard.Conclusion:After the external electrically-driven MLC is installed on the accelerator, the dosage of IMRT can achieve the verification standard, and it can be applied to clinical treatment and can satisfy the requirement of clinical radiotherapy.
ABSTRACT
Objective:To verify the dose of static and dynamic intensity modulated radiotherapy (IMRT) through 2-dimension ionization chamber matrix after external electrically-driven multi-leaf collimator (MLC) was installed in KB1800 medical linear accelerator. Methods: 40 patients who need receive IMRT were divided into static IMRT group (20cases) and dynamic IMRT group (20cases) as the random number table. The ionization chamber was applied to implement scale dose, and solid water and 2-D ionization chamber matrix was applied to verify dose. Besides, the feasibility of static and dynamic IMRT were compared and researched.Results: The verification results of plane dosage of static IMRT plan and dynamic IMRT plan showed that the passing rates both of them were above 90.0%, and the verification of intensity modulated dosimetry of medical electric linear accelerator KB1800 with external electric MLC was consistent with standard.Conclusion:After the external electrically-driven MLC is installed on the accelerator, the dosage of IMRT can achieve the verification standard, and it can be applied to clinical treatment and can satisfy the requirement of clinical radiotherapy.
ABSTRACT
<p><b>OBJECTIVE</b>To study the expression of ET receptor and the apoptosis after intervened with ET receptor antagonist in androgen-independent prostate cancer.</p><p><b>METHODS</b>PC3, an androgen-independent prostate cancer cell line, was used. The expression of ETA and ETB receptor in PC3 was measured through RT-PCR. After intervened with selective ETA and ETB receptor antagonist, the apoptosis in PC3 was studied through flow cytometry and electron microscope.</p><p><b>RESULTS</b>Clear signal was obtained in PC3 for ETA receptor mRNA transcript, while the signal for ETB receptor mRNA transcript was very weak. The expression of ETA receptor mRNA was obviously reduced and the apoptosis of PC3 cell was observed after intervened with selective ETA receptor antagonist. There was no change after intervened with selective ETB receptor antagonist.</p><p><b>CONCLUSION</b>ET-1 exerts its effects through the ETA receptor subtype and ETB receptor is silenced in PC3. The expression of ETA was reduced and the apoptosis was observed in PC3 when ETA receptor was blocked. It was dose-dependent.</p>