ABSTRACT
Valproic acid is used in the epilepsy, bipolar and migraine therapy. As a histone deacetylase inhibitor, Valproic acid has been recently under investigation in cancer treatment, either alone or in combination with either chemotherapy or radiotherapy. This study was done to determine the effect of Valproic acid and radiotherapy on viability of MCF-7 breast cancer cell line. In this descriptive - analytic study, MCF-7 cell line was obtained from the Iranian Pasteur Institute. The cells were treated and incubated by different concentrations of Valproic acid [1, 2, 4, 8, 16, 32, 64 and 128 mM] either alone or in combination with various dosages [0 .5, 2, 4, 6 and 8 Gray] of radiotherapy. After cell viability assay, using the Neutral red staining, the most nearest results to LD50 were selected. Cell viability was evaluated with trypan blue staining. The most nearest concentrations of LD50 was doses of 2, 8 and 16 mM of valproic acid and dosage of Gray 4 of radiation. There was a significant dose-dependent correlation between reduction of cell viability with valproic acid concentration [P<0.05]. Valproic acid, either alone or combination with radiotherapy caused a significant decline in the cell viability of MCF-7 breast cancer cell line
ABSTRACT
A prototype stereotactic radiosurgery set was designed and constructed for a Neptun 10 PC linac that is currently being used at Imam Reza hospital in Mashhad. A complete quality assurance program was designed and performed for the constructed system including isocentric accuracy test, localization accuracy test, dose delivery accuracy test and leakage radiation test. Target simulator, control alignment device and plexiglass phantom which were parts of the developed hardware were used to fulfill quality assurance program. The average isocentric shift resulted from the gantry rotation and couch turning were respectively obtained to be 1.4 and 2 mm. The average localization error in the three coordinates was found to be 2.2 mm. The total treatment uncertainty due to all of the probable errors in the system was equal to 4.32 mm. The dose delivery accuracy test was carried out, the result indicated a 3-7% difference between the given and measured dose. The quality assurance tests showed consistent performance of the constructed system within the accepted limits; however, some inconsistency might exist in certain cases. The safety of SRS method is increased when the overall uncertainty is minimized and the treatment of the lesions adjacent to critical organs is avoided