ABSTRACT
Objective: To evaluate the potential dosimetric beneifts and optimal indications of intensity modulated radiation therapy (IMRT) and hybrid intensity modulated radiation therapy (Hybrid IMRT) for the left side breast cancer patients after breast-conservation therapy. Methods: Eight patients with left breast carcinoma who received breast-conservation surgery were selected for this study. Two plans were designed in 3-dimensional treatment planning system. The dose distributions of target volume and normal tissues, conformal index (CI) and heterogeneous index (HI) were analyzed by dose-volume histogram (DVH). Results: The PTV coverage was the same in the two radiotherapy plans. A better dose uniformity throughout the whole breast in Hybrid IMRT plan was achieved. The CI, the percentage of PTV receiving more than 105% prescribed dose (V105%), the percentage of PTV receiving more than 110% prescribed dose (V110%), and the Dmax, Dmin and Dmean of PTV were similar in the two plans. We compared the Hybrid IMRT with IMRT: V13of the ipsilateral lung decreased from 27.66% to 20.7%, V5 of the contralateral lung decreased from 8.01% to 2.25%, V10 and V20 of the heart decreased from 35.23% and 16.77% to 19.22% and 10.6% respectively, V5 and V10 of the contralateral breast decreased from 35% and 10.39% to 20.38% and 5.7% respectively, all with significant difference. V30 and V40 of the ipsilateral lung and V40 of the heart increased by 1.28%, 1.48%, and 2.48%, with signiifcant difference. Conclusion: Hybrid IMRT is a better choice for patients whose treatment position is inaccurate or cannot be repeated well.
ABSTRACT
OBJECTIVE@#To investigate the inhibitive effect of E1A gene carried by PEI-Fe(3)O(4) nanometer particle (NP) on the cell growth of human cervical carcinoma cell in vitro and its mechanism, and to provide the experimental evidence for the feasibility of gene therapy for human cervical carcinoma.@*METHODS@#E1A gene conjugated to PEI-Fe3O4 NP was transfected into human cervical carcinoma cell line Hela. The cell growth curve of Hela was drawn, the doubling time and the number of colony formations on the soft agar were calculated based on the cell count. RT-PCR and Western blot were used to detect the expression of the E1A and HER-2/neu in Hela cells.@*RESULTS@#The cell doubling time of Hela cells transfected with E1A gene (Hela-E1A) was 1.53 times and 1.58 times longer than that of the Hela transfected with blank vector (Hela-vector) and blank Hela control (Hela), respectively. The E1A transfected Hela cells grew slower than those of the control group. The cell colony formation efficiency in the Hela-E1A (6.62%) group was significantly lower than that of Hela (30.48%) and Hela-vector (28.3%) groups (P<0.05). As compared to Hela and Hela-vector, the inhibition rate of Hela-E1A was 78.28% and 76.62% respectively. RT-PCR and Western blot demonstrated that the overexpression of E1A through gene transfection significantly inhibited mRNA and protein expression of HER-2/neu in Hela cells.@*CONCLUSION@#E1A gene can suppress the cell growth of human cervical carcinoma cell Hela in vitro. Down-regulated expression of HER-2/neu gene by E1A overexpression in Hela might contribute to the Hela growth inhibitive effect of E1A.