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Objective To present and discuss beam characteristics of the first Mevion S250i gantry-mounted accelerator pencil beam scanning proton therapy system in China.Methods The output dose was measured using a parallel-plate ionization chamber.The integrated depth dose was measured with a large-radius Bragg peak ionization chamber,covering 19 energy levels ranging from 227 MeV to 28 MeV,to analyze the proton beam characteristics.The spots in the air were measured with Phoenix flat panel detector on the beam central axis,and the precision of the delivery position was verified by measuring the multi-spot beam map.The interleaf leakage and penumbra reduction of adaptive aperture were measured to characterize its performance.Results The proton system was calibrated for a maximum energy of 227 MeV,with a(10×10)cm2uniform field delivering 1 Gy dose at a depth of 5 cm underwater.The system effectively modulated the proton beam range to the patient's surface,maintaining a constant 80%-80%Bragg peak width of 8.6 mm at all energy levels.The spot size of the highest energy beam at the isocenter was about 4 mm in the air,and the spot delivery position error was less than 1 mm.The interleaf leakage rate of the adaptive aperture for the highest energy beam was below 1.5%,and the penumbra was significantly reduced.Conclusion Mevion S250i proton therapy system demonstrates unique design and beam characteristics,which is reflected in the Bragg peak shape,spot size variation with energy,and penumbra sharpening of adaptive aperture;and these differences should be considered in treatment planning system modeling and planning for precision treatment.
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Objective:To evaluate the clinical application value of the adaptive aperture by comparing intensity-modulated proton radiotherapy(IMPT) plans using and not using the aperture for brain tumors.Methods:A total of twenty patients treated with postoperative radiotherapy for brain tumors were enrolled in this study. IMPT plans were developed for each patient using and not using the adaptive aperture under the same optimization conditions. The target conformal index (CI) value, target homogeneity index (HI) value, and the dose to normal tissues of the two sets of plans were compared.Results:The IMPT plans designed using the adaptive aperture significantly increased the mean CI value from 0.58 to 0.66, while decreasing the mean 50% prescription dose volume from 797.70 cm 3 to 638.15 cm 3. These plans also reduced the irradiation doses to the cochlea, brainstem, optic chiasm, optic nerve, and lens ( t = 2.06, 3.02, 2.11, 2.58, 2.67, P < 0.05). Additionally, there was no significant difference in the HI value of the target volumes and the machine jumps (MU) between the two sets of plans ( P > 0.05). Conclusions:The adaptive aperture can significantly reduce the irradiation dose to normal tissues outside the target volumes, positively impacting the protection of organs at risk (OARs) around the target values. This demonstrates its great potential for clinical application.
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China has a heavy burden of hepatocellular carcinoma, which is a serious threat to people′s life and health. However, the available drugs for advanced hepatocellular carcinoma in the past are limited and the efficacy is not satisfactory. In recent years, immunotherapy has a significant effects in some tumors. The authors introduce the efficacy of restart immunotherapy on an advanced hepatocellular carcinoma patient undergoing interruption of treatment due to corona virus disease 2019, in order to provide references for the diagnosis and treatment of this kind of patients.
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Most patients with primary liver cancer in China are in the advanced stage at initial diagnosis and lose the opportunity for surgical treatment, and therefore, how to reduce advanced liver cancer to resectable liver cancer is a hot topic in clinical research in recent years. The key premise of successful conversion is to screen out the individuals who are suitable for conversion or may achieve successful conversion through comprehensive examination and necessary multidisciplinary consultation. This article introduces the conversion strategy and the antitumor strategy for liver cancer with lung metastasis, portal vein tumor thrombus, massive tumor dissemination, or multiple tumors, liver cancer with liver function decompensation, liver cancer with liver cancer dissemination and metastasis and an ECOG constitution score of ＞2, and liver cancer with a high HBV load, which has certain guiding significance in the downstaging conversion therapy for advanced liver cancer in clinical practice.
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Objective@#To explore the effect of drawing therapy on the behavior of children with attention deficit hyperactivity disorder (ADHD), and to provide a new perspective for the treatment of children with attention deficit hyperactivity disorder (ADHD).@*Methods@#In June 2019, a random sample of three primary schools in 1-6 grade in Baishan who diagnosed with ADHD was recruited, the experimental group 10 ADHD children were given painting therapy intervention for 14 weeks, four times a week, 120 mins each time, the control group 10 ADHD children received no intervention. During the study period all the participants do not receive any other treatment. The ADHD Rating Scale Parent version,the Conners Parents Symptom Questionnaire(PSQ) and the Rey Complex Figure test was assessed before and after the intervention to evaluate the symptoms of ADHD children.@*Results@#In terms of PSQ score test, there were significant differences between the scores of four dimension factors in the experimental group after therapeutic intervention and those before intervention and those after intervention in the control group(P<0.05). The follow-up test showed that the PSQ score in the experimental group remained good (P<0.05). There were two dimension factors that were not significantly different in the post-test and follow-up post-test and before intervention. In Rey complex memory graph test score test, it was found that the score of four dimensions after intervention in the experimental group was significantly different from that before intervention and after intervention in the control group (P<0.05). After 12 weeks, the score of follow-up test remained good (P<0.05).@*Conclusion@#Painting therapy has a significant effect on ADHD children’s behavioral management ability and working memory ability, and the effect can last for at least 12 weeks.
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Objective To investigate the accuracy and application value of optical surface monitoring system in intensity modulated radiotherapy for thoracic tumors patients.Methods Twenty-eight patients with thoracic tumors were included.During each treatment fraction,the patients were immobilized with body surface markers and laser lamps.The surface images obtained by the optical surface monitoring system were registered with the reference images and recorded during the CBCT scan.The translation and rotation errors of x (left-right),y (craniocaudal) and z (anterior-posterior) axes were recorded.After scanning,the CBCT images were registered with the planned CT images and the translation and rotation errors of x,y and z axes were recorded.The setup errors of these two image systems were analyzed and corrected before each treatment.The correlation between the two sets of setup errors were analyzed with Pearson test,and systematic error (∑) and random error (σy) were also calculated.The consistency of the two image systems was evaluated with the Bland-Altman method and the 95％ limits of agreement were calculated.Results There was a good correlation between these two groups,and the correlation coefficients were 0.79,0.62,and 0.53 in x,y and z axes,respectively.The ∑/σr of the optical surface monitoring system were 0.7 mm/1.5 mm,0.9 mm/1.8 mm and 0.9 mm/1.5 mm in x,y and z axes,respectively.The ∑/σ of CBCT were 0.8 mm/1.6 mm,1.3 mm/1.9 mm and 0.7 mm/1.5 mm in x,y and z axes,respectively.The 95％ limits of agreement of translations direction were (-2.0-2.3),(-3.4-3.6) and (-3.3-2.4) mm,and the 95％ limits of agreement of rotation direction were (-2.0 to 1.6)°,(-2.0 to 1.4)° and (-1.6 to 1.6)° inx,y and z axes,respectively.Conclusions The optical surface monitoring system is an effective image guide tool,which can quickly and accurately verify the patient's position and improve the position accuracy.It can be applied for positioning in the intensity modulated radiation treatments for the thoracic tumor patients.
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Objective To investigate the design and manufacture of 3D printed compensator in electron radiation therapy for Merkel cell carcinoma,and to verify the feasibility of this technique in electron radiation therapy.Methods Computed tomography was used to collect images of a human head phantom.The delineation of target volume of Merkel cell carcinoma was simulated in the planning system and a radiotherapy plan was formulated after adding the compensator.The compensator was printed out by a 3D printer and fixed on the head phantom.A second CT scan was performed to make a new treatment plan.For the two plans,several planes parallel to the beam were selected to calculate gamma passing rates.The actual dose distribution was measured using disposable films.The gamma passing rate was compared between the film system and the planning system.The conformity index (CI) and the heterogeneity index (HI) of target volume were compared between the plans using the printed compensator and the conventional compensator of the same thickness.Comparison between the two plans was made by paired t test.Results Using the dose distribution of the plan with simulated compensator,the gamma passing rate was 94.7±2.3％ in the plan with 3D printed compensator.Using the dose distribution measured by the film,the gamma passing rate was 96.6％ in the plan with 3D printed compensator.Compared with the conventional compensator,the 3D printed compensator achieved a significantly elevated CI (0.85 vs.0.69,P=0.004) and a slightly improved HI (1.30 vs.1.26,P=0.001).Conclusions The conformal dose distribution provided by 3D printed compensator for tumors at different depths meets the clinical need.
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Background and purpose:Hypoxia induced the decreased radiosensitivity of tumor cells, which was the cause of tumor radioresistance and relapse and metastasis. During the course, HIF-1a played the most important role in the regulation of hypoxia. However, it’s still unknown about the effect of HIF-1a on the radiosensitivity of hypoxia tumor cells and the relationship with autophagy. This study was to inhibit HIF-1αexpression in hypoxic lung adenocarcinoma cell line A549 with RNA interference (RNAi), and explore its effect on hypoxic cell radiosensitivity and autophagy. Methods: Plasmids pHIF-1α-shRNA and Neg-shRNA (negative control) were constructed and transfected into hypoxic A549 cells, this positive clone was named A549/HIF-1α-shRNA. Clone formation array was applied to calculate the value of D0, SF2, SER. The expression of HIF-1α, LC3, c-parp was detected by Western blot. Results:The SF2 of hypoxic A549 cell was 0.62, which was higher than that of normoxic A549 cell, SER was 1.45. The level of LC3Ⅱincreased significantly and the level of c-parp decreased after the radiation of hypoxic A549 cell. The level of HIF-1a increased in hypoxic A549 cells. The expression of HIF-1αin hypoxic A549 cells was suppressed markedly after transfection of HIF-1α-shRNA;this clone was named A549/HIF-1α-shRNA. The SF2 and SER were significantly lower in A549/HIF-1α-shRNA cells, 0.45 and 0.72 respectively. Under the hypoxic condition and after the inhibition of HIF-1α, the expression of LC3Ⅱ decreased significantly and the expression of c-parp increased. Conclusion:We successfully established a cell model that HIF-1αexpression was suppressed almost completely by RNAi. The inhibition of HIF-1αby shRNA may raise the radiosensitivity and decrease the autophagy of hypoxic A549 cells in vitro.
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Background and purpose:HIF-1?、HER-2 and survivin are all considered as important prognostic factors of breast cancer,but the relationships among them are poorly understood.We investigated the expression of HIF-1?、HER-2 and survivin in Breast Carcinoma,and explored the relationship among the three prognostic factors.Methods:The expressions of HIF-1?、HER-2 and survivin were detected by immunohistochemistry in 51 human Breast Carcinoma samples.Results:① 28(54.88%),11(21.69%) and 35(68.62%) were positive for HIF-1?、HER-2 and survivin,respectively.② A significant difference was found in terms of the overexpression of HER-2 between the samples with HIF-1? either positive or negatiwe(P0.05).Conclusions:The positive expression of HIF-1? was strongly correlated with the overexpression of HER-2,but not survivin in breast carcinoma.
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Hypoxia is very common in solid tumor.It results in a series of changes of biological behavior in tumor cells.Hypoxia could facilitate malignant cells metastasis,in which the hypoxia inducible factor-1 plays an important role.The hypothesis for the tumor cells to metastasis is the degradation of the extracellular matrix(ECM).The ECM can be degraded by the matrix metalloproteinase,which is a critical factor in the process of tumor-metastasis.So far,it is not clear whether hypoxia have a role in the regulation of MMPs in tumor.So this review summarize the advanced knowledge on the influence of HIF-1 and MMPs in tumor-metastasis and the interaction between two genes.
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Summary: To study the effects of hypoxia on the expression of P-gp and mutltidrug resistance protein in human lung adenocarcinoma A549 cell line, and to explore the probable mechanism of hypoxia in tumor cell of MDR. The expression of hypoxia inducible factor-1α, P-gp and mutltidrug resistance protein was immunohistochemically detected by culturing human lung adenocarcinoma A549 cell under hypoxia (2 % O2) for 24 h. After interaction with adriamycin or cisplatin under hypoxia (2 % O2) for 24 h, the cell survival rate was detected by MTT. Our results showed that the expression of hypoxia inducible factor-1α, P-gp and mutltidrug resistance protein under hypoxia were higher than the expression under normoxia, and correlations between the expression of HIF-1α and P-gp or multidrug resistance-associated protein was observed (P<0.05). The resistance of adriamycin of A549 cell was enhanced under hypoxia. It is concluded that the resistance of tumor chemotherapy is enhanced in hypoxia. The expression of HIF-1α is obviously correlated with the expression of P-gp and mutltidrug resistance protein.
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The expression of DNA ploidy, the cell cycle and Ki67 antigen in nasopharyngeal carcinoma (NPC) were studied and their relationship with the clinical biological behaviors and prognosis of NPC was evaluated. Biopsied specimens of NPC were made into cell suspension. By using cytometric double labeling Ki67 and DNA method, the expression of DNA ploidy, the cell cycle and Ki67antigen were analyzed. The patients were followed-up for about 3 years and the relationship between the above-mentioned parameters and the clinical biological behavior and prognosis of NPC were evaluated. Of the 62 cases of NPC, the DNA aneuploid accounted for 29.03 %. The S phase cells accounted for 0 to 54 % in the cell cycle and the positive expression of Ki67 ranged from 0 to 52 %.There were 40 cases of LPI (64.5 % ) including 15 negative cases and 22 cases of HPI (35.5 % ) respectively. The DNA anueploid content was positively related to the S phase cells. The patients having a low expression of Ki67 or DNA aneuploid in tumor cells were not sensitive to chemotherapy, liable to metastasis to distant organs and had a poor prognosis, while Ki67 showed no correlation with DNA ploidy and the cell cycle. It was suggested that DNA ploidy and Ki67 could be used as an independent and objective marker to evaluate the radiosensitivity and prognosis of NPC.
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<p><b>BACKGROUND</b>To explore the expression level and its clinical significance of hypoxia inducible factor 1α (HIF-1α) in non-small cell lung cancer.</p><p><b>METHODS</b>The expression of HIF-1α was detected in 68 human non-small cell lung cancer samples by immunohistochemistry.</p><p><b>RESULTS</b>Thirty-nine (57.35%) out of 68 human non-small cell lung cancer samples were positive for HIF-1α. The positive rate of HIF-1α in adenocarcinoma was 54.76% (23/42) and 61.54% (16/26) in squamous cell carcinoma ( P > 0.05) respectively. The positive rate of HIF-1α in moderate- to well-differentiated samples was 74.29%(26/35) and 39.39%(13/33) in low-differentiated samples respectively ( P < 0.05). The expression rate of HIF-1α in I-II stage ( 86.96%, 20/23) was significantly higher than that in III-IV stage (42.22%,19/45)( P < 0.05). The positive expression of HIF-1α was not related to sex and age of patients and lymph node status.</p><p><b>CONCLUSIONS</b>High expression of HIF-1α exists in non-small cell lung cancer, and it may be related to cell differentiation and TNM stage of tumor. The results suggest that resistance to radiotherapy and chemotherapy induced by HIF-1α should be considered in the treatment of non-small cell lung cancer.</p>
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Most patients with primary liver cancer in China are in the advanced stage at initial diagnosis and lose the opportunity for surgical treatment, and therefore, how to reduce advanced liver cancer to resectable liver cancer is a hot topic in clinical research in recent years. The key premise of successful conversion is to screen out the individuals who are suitable for conversion or may achieve successful conversion through comprehensive examination and necessary multidisciplinary consultation. This article introduces the conversion strategy and the antitumor strategy for liver cancer with lung metastasis, portal vein tumor thrombus, massive tumor dissemination, or multiple tumors, liver cancer with liver function decompensation, liver cancer with liver cancer dissemination and metastasis and an ECOG constitution score of ＞2, and liver cancer with a high HBV load, which has certain guiding significance in the downstaging conversion therapy for advanced liver cancer in clinical practice.