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Objective To compare the dose distribution and setup error of angled breast board position ( ABB) with plain breast board position ( PBB) in breast cancer radiotherapy. Methods Twenty consecutive postoperative left breast cancer patients in the First Affiliated Hospital, Zhejiang University were enrolled from March 2017 to January 2018. All cases were assigned into the ABB and PBB groups according to positions and there were 10 cases in each groups respectively. The target volume, heart and lung structures were defined on the CT images of the localized scan. The plan was designed using the field in field ( FIF) technique to compare the dosimetric parameters of the PTV, lung, and heart treatments, and the setup errors for the two different positions. Results The ipsilateral lung V20[ABB:(11.2 ±3.2)％, PBB:(15.9 ±5.3)％, t= -2.47,P< 0.05], and V30[ABB:(9.8 ±1.5)％, PBB:(12.9 ±2.2)％, t= -4.46,P<0.05] were both statistically significant for the two different position and immobilization. Heart dose V25[ABB: (1.9 ± 0.2)％, PBB: (2.8 ± 0.4)％, t = -8.28, P <0.05], V30 [ABB:(1.8 ±0.1)％, PBB: (2.7 ± 0.3)％, t = -8.34,P < 0.05], and Dmean of heart [ABB: (3.0 ±0.5)Gy, PBB:(5.3 ± 1.2)Gy, t=5.58,P<0.05] were all statistically significant for the two different positions. The translational errors of ABB and PBB on LR, SI, and AP were ( 3.23 ± 2.63 ) , ( 5.42 ± 3.22), (4.58 ± 2.30) mm, and (2.35 ± 1.22), (2.17 ± 1.29), (2.27 ± 1.58) mm, respectively. The rotation errors of pitch(θ), yaw(Φ) and roll(ψ) for ABB and PBB were (1.60 ± 0.56)°, (3.40 ± 1.65)°, (2.50 ± 1.72)°, and (1.37 ± 0.43)°, (1.79 ± 0.71)°, (2.06 ± 0.63)°, respectively. Meanwhile, the in-and out-SI, anterior and posterior AP, yaw rotation error (Φ) were also statistically significant(t=3.06, 2.80, 3.33,P<0.05). Conclusions There is no statistically significant difference in the tumor target between the two position and immobilization techniques. However, the ABB is better than the PBB in normal tissue sparing while the setup accuracy of PBB is better than the ABB.
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Objective To compare the dosimetric results of postoperative intensity modulated radiation therapy (IMRT) using single-energy or mixed-energy photons in invasive thymoma patients.Methods Simulation CT images were acquired and clinical target volume (CTV),planning target volume (PTV) and organs at risk (OARs) were defined.Three sets of fixed-field IMRT planning were generated using 6 MV,10 MV and mixed 6/10 MV photons for each case.Monitor Units (MUs) for each plan were recorded after optimization,and parameters of PTV such as conformity index (CI),homogeneity index (HI) and dose to OARs were evaluated on dose-volume histograms.Results Near-Maximal dose (D2％) received by PTV was better in mixed-energy IMRT as compared with 6 MV(t =3.107,P ＜0.05).HI was better in mixed-energy than in 6 MV(t =2.924,P ＜0.05).There were statistically significant differences in CI among three IMRT plans.MU was higher in 6 MV than in both 10 MV and mixed-energy IMRT.The percentages of lung volumes receiving 5 Gy (V5),10 Gy(V10),20 Gy (V20),30 Gy (V30) and the mean lung dose (D) were also significantly different in most plans.V30 and V40 of the heart were comparable between 6 MV and mixed energy plans but better than in 10 MV plan.Conclusions If the reasonable choice of beam angles and number,and capability of energy selection according to beam directions,with combined advantages of low and high energy photons,mixed IMRT plans can improve the quality of IMRT plans in general and has clinical potential for postoperative radiotherapy of invasive thymomas.
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Objective To explore the radiosensitivity of berberine on esophageal cancer cells under hypoxia condition.Methods MTT assay and clonogenic survival assay were used to evaluate the effect of berberine on proliferation inhibition and radiosensitivity of esophageal cancer cells,respectively.Immunofluorescence was employed to examine the expression of HIF-1.The change of cell cycle distribution and cell apoptosis was assayed by flow cytometry.The expression of HIF-1 was measured by Western blot.DNA damage was detected by γ-H2AX Foci counting.Results With a clear dose and time effect,berberine inhibited cell proliferation and enhanced cell radiosensitivity(t =3.69,P＜0.05)with a sensitizing enhancement ratio(SER)of 1.42.Berberine caused a dose-dependent decrease in HIF-1 protein expression and also significantly increased the cell apoptosis in ECA-109 population(t=4.74,P＜0.05).Compared with the radiation alone group,berberine enhanced X-ray induced DNA double chain breaks(DSB).Conclusions Berberine can increase the radiosensitivity of esophageal cell line ECA-109,which may be associated with decrease of HIF-1 expression and induction of apoptosis in ECA-109 cells.