Clinical and pathological characteristics of intraductal proliferative lesions and coexist with invasive ductal carcinomas

Objective： The purpose of this study was to study the clinical and pathological characteristics of breast intraductal proliferative lesions （IDPLs） and associated with invasive breast cancer. Methods： We reviewed 327 cases of breast intra- ductal proliferative lesions including 53 cases of usual ductal hyperplasia, 57 cases of atypical ductal hyperplasia, 89 cases of ductal carcinoma in situ, and 128 cases coexist with invasive ductal carcinomas. Cases of pure invasive cancer without intraductal proliferative lesions were excluded. The mult IDPLs biological parameters including the express of ER, PR, HER2, HIF-lo and Ki-67 detected by immunohistochemistry S-P method （n = 327） and the levels of CA153, TSGF, CA125 and CEA both in nipple discharge and serum （n = 179） measured with Electrochemiluminescence method and their relationship were studied, and 30 cases of normal pregnant women were compared with. Results： A single histologic subtype was present in 49.85% （163/327） of the cases, two subtypes in 33.03% （108/327）, and three in 17.13% （56/327）. The most common subtypes present were cribriform （43.12%, 141/327） and solid （38.53%, 126/327）, while the comedo （16.35%, 54/327）, and micropapillary （12.84%, 42/327） subtypes were less common. Comedo and solid were frequently found together for coexpres- sion as were micropapillary and papillary subtypes. However, Comedo subtype was much less likely to be found with papillary, cribriform or micropapillary subtypes. Additionally, comedo subtypes tend to be hormone receptor negative, Her2 positive and high-grade while the cribriform and solid subtype tends to be hormone receptor positive, Her2 negative and low grade. Papil- lary subtype was least likely to be associated with an invasive cancer. Furthermore, the nipple discharge and serum levels of CA153, TSGF, CA125 and CEA in coexist with invasive ductal carcinomas patients were significantly higher than those in the benign breast disease （pure intraductal proliferative lesions） and normal pregnant women （P 〈 0.01）. Additionally, the levels of CA153, TSGF, CA125 and CEA in nipple discharge were significantly higher than in the serum （P 〈 0.01）, and had a positive correlation with the Ki-67, grade, clinical stage, lymph node metastasis and tumor recurrence （P 〈 0.05）, and negative correla- tion with the level of ER and PR （P 〈 0.05）. The sensitivity of the four serum tumor markers in combination was only 69.77%, in contrast, the combined detection both in discharge and serum was 97.67%, and the negative predictive value was 99.03%. The sensitivity of combined detection both in nipple discharge and serum were significantly higher than other detection （P 〈 0.05）. Conclusion： IDPLs often present more than one histologic subtype and the most common subtypes are cribriform and solid, while comedo and micropapillary subtypes are less common. Our results suggest that the levels of CA153, TSGF, CA125 and CEA in nipple discharge were significantly higher than those in the serum, and is associated with HIF-le. The aberration of HIF-la may play a key role during oncogenesis and promote breast cellular transformation into malignancy, a finding useful for further understanding of tumorigenesis. Nipple discharge can be the earliest presenting symptom of breast cancer. The dynamic combined detection of the four tumor markers both in nipple discharge and serum are helpful to the stratification of preoperative patients and benefit to better prewarning markers for monitoring their recurrence and metastasis and clinical staging of tumors in clinic, but cannot increase the sensitivity of judging the patients with early breast cancer.     

Comparison of vinorelbine plus cisplatin with vinorelbine plus capecitabine in patients with anthracyclines- and taxanes-refractory advanced breast cancer

Objective： The aim of our study was to compare the efficacy and toxicities of vinorelbine plus cisplatin （NP） regimen with that of vinorelbine plus capecitabine （NX） regimen in the treatment of anthracycline- and taxane-refractory advanced breast cancer. Methods： Forty-six patients with anthracycline- and taxane-refractory advanced breast cancer were equally randomized into a NP group （n = 23） and a NX group （n = 23）. Response rates and toxicities were evaluated after 2 cycles of chemotherapy. Results： The overall response rate were 48.0% in both groups. There were no significant differences in disease control rates （78.0% vs. 83%） or 1-year survival rates （54.6% vs. 55.9%）. The main adverse events were bone marrow depression and gastrointestinal reaction, and no significant difference was found in toxicities between the groups. Conclusion： For anthracycline- and taxane-refractory advanced breast cancer, NP and NX regimens exerted similar curative effects with acceptable toxicity.     

The effect of different inflation volumes of laryngeal mask airway on efficacy of closed circuit controlled ventilation in pediatric cancer patients

Objective： The laryngeal mask airway （LMA） is an established way for airway control during spontaneous ventila- tion. Its ability to deliver positive pressure ventilation without leakage especially in low flow states is still controversy. The aim of this study is to test the possibility of using LMA in pediatric closed circuit controlled ventilation, and to find out the optimum cuff volume to perform closed system ventilation. Methods： Twenty children scheduled for elective surgeries were enrolled in a crossover study. Laryngeal mask airway was used. In stage I, the cuff was inflated with the maximum volume of air as rec- ommended by the manufacturers. Adjustment of volume of air inflated into the LMA cuff to the minimum volume to obtain the effective seal was done at stage II. The leak pressure, intracuff pressure and the leak volume were measured in both stages. Results： The cuff filling volume was significantly lower compared to the maximum cuff inflation volume in stage I. Leakage values showed significantly less values in stage II of the study with smaller cuff inflation volumes. The airway leakage pressure was significantly lower in stage fl in comparison to stage I. Cuff inflation pressure in stage I showed marked elevation which dropped significantly after adjustment of cuff volume in stage I1. Conclusion： Laryngeal mask airway is an effective tool to provide closed circuit controlled ventilation in pediatrics. Inflation of the cuff by the minimum volume of air needed to reach the just sealing pressure is suggested to minimize the leakage volume.     

Application of non-small cell lung cancer pleural effusion cell blocks in molecular pathological detection

Objective： The tumor tissues used in molecular pathological detection were usually obtain,ed by surgery, which would cause trauma and may not be suitable for the terminal cancer patients. This paper evaluated the value of the non-small cell lung cancer （NSCLC） pleural effusion cell blocks as tumor tissues replacement materials in the application of molecular pathological detection. Methods： Tumor cells were made into cell blocks through stratified centrifugal from 30 NSCLC pa- tients with the pleural effusion. The immunohistochemistry, fluorescence in situ hybridization （FISH） and gene sequencing methods were employed in our experiments. Results： The tumor cells of cell block section were rich and could keep part of histological structure. Immunohistochemistry staining could assist diagnosis and tumor parting. Epidermal growth factor receptor （EGFR） FISH-positive was found in 33.33% of the group, high polysomy in 6 cases, amplification in 4 cases. EGFR gene mutations were found in 8 cases of 30 samples, with an incidence of 26.67%, 6 cases were detected in the exon 19, and 2 cases were detected in the exon 21. Conclusion： The NSCLC pleural effusion cell blocks are useful for the diagnosis and determining the primary source of tumor, instructed targeted therapy.     

Genetic variants in telomere-maintenance genes and bladder cancer risk

Telomere maintenance genes play an important role in maintaining the integrity of the telomere structure that protects chromosome ends, and telomere dysfunction may lead to tumorigenesis. Genetic variation in telomere maintenance genes has been confirmed. Cumulative evidence shows that the difference of telomere length and stability among the indi- vidual depends on the genetic variants of telomere maintenance genes. Genetic variants in telomere maintenance genes may affect telomere length and stability, thus the increased cancer risk. This review intends to summarize the association of genetic variants in telomere maintenance genes with bladder cancer risk.     

The latest advances of experimental research on targeted gene therapy for prostate cancer

The absence of effective therapies for castration-resistant prostate cancer （CRPC） establishes the need to de- velop novel therapeutic modality, such as targeted gene therapy, which is ideal for the treatment of CRPC. But its application has been limited due to lack of favorable gene vector and the reduction of ＂bystander effect＂. Consequently, scientists all over the world focus their main experimental research on the following four aspects： targeted gene, vector, transfer means and comprehensive therapy. In this paper, we reviewed the latest advances of experimental research on targeted gene therapy for prostate cancer.     

The 5-year incidence of male breast cancer in Southwest of China from 2007 to 2011

Objective： Male breast cancer is a rare disease with an incidence of about 1% of breast cancers in USA, but relatively lack of the information of male breast cancer in China, especially in Southwest of China, led us to study its incidence trends. Methods： Chongqing is one of the biggest and the most important areas that is located in Southwest of China. There are around 31.4 million people who live in approximate 82 402.95 km2 area of Chongqing. Data about breast cancer patients registered in the Center for Disease Prevention and Control of Chongqing （China） were statistically collected from 187 hospi- tals, about 58 hospitals in city and 129 hospitals in country, and over 6.2 million people were studied every year. It was tried to represent all the people in villages and cities in Chongqing, China. Results： The incidence of male breast cancer in Southwest of China ranged from 0.34/100 000 to 1,45/100 000 between 2007 and 2011, while the incidence of female breast cancer ranged from 15.40/100000 to 21.66/100000 at the same time. The rate of male breast cancer to female breast cancer ranged from 0.02：1 to 0.07：1, male breast cancer accounted for 1.96% to 6.5% （with the mean value of 2.9%） of breast cancers in Southwest of China from 2007 to 2010. Conclusion： In Southwest of China male breast cancer accounts for about 2.9% of breast cancers which is higher than that in United States. It is important for policy makers and health manager to seriously consider breast cancer in future plan in Southwest of China.     

Clinical pathology analysis of esophageal sarcomatoid carcinoma

Objective： The purpose of this study was to study the clinical, imaging characters and pathological characteristics of esophageal sarcomatoid carcinoma. Methods： We reviewed 23 cases of esophageal sarcomatoid carcinoma from Janu ary 2006 to December 2013 in four hospitals. The data of patients who were esophageal sarcomatoid carcinoma operated were retrospectively analyzed. All cases had completed upper gastrointestinal barium images materials and 14 of these cases had completed CT images materials. Upper gastrointestinal barium images and CT imaging features include tumor location, size, shape, and strengthen, etc. The biological parameters of lesions including the express of cytokeratin AE1/AE3, 34E12,, Vimentin, desmin, Actin, S100 and Ki67 detected by immunhistochemical UltraSensitiveTM SP method （n = 23）, and the patients＇ data of contrastographic picture （n = 23）, imaging characters of CT scan （n = 14）, and their relationship were studied. Results： Upper gastrointestinal barium images, CT imaging and gastrointestinal fiberscopy revealed Iobulated intraluminal filling defect 0.4 cm to 5.7 cm x 3.5 cmx 1.3 cm （mean = 3. 7 cm） in the mid （n = 14）, lower （n = 7） and upper （n = 2） intrathoracic esophagus. Among 23 cases of esophageal sarcomatoid carcinoma, 19 patients were of mushroom type, 2 patients was of ulcer type, and 2 patients were of medulla type; 19 patients were pedunculated, and 4 patients were no pedunculated （2 patients was of ulcer type）. The tumor surface was relatively smooth and esophageal compliance was maintained. The pathological changes of esophagus such as lightly locked, rigid wall nomanifest partly, esophageal lumens expand partly, major filling sublobe defect could be shown through contrast medium. Normal esophagus was no unpack obviously over pathological changes. Enhanced computed tomography showed tumors in the intrathoracic esophagus and 8 lymph nodes metastases in 3 cases. Histologically, carcinomatous and sarcomatous components coexist. Microscopically, the tumor comprised poorly differentiated squamous cell carcinoma and spindleshaped cells resembling leiomyosarcoma. Immu nohistochemically, spindleshaped sarcomatous cells displayed weekly positive reaction to cytokeratin AE1/AE3. Transitional zone was seen between sarcomatous and carcinomatous elements in 5 cases. The 17 lymph nodes metastases in 5 cases （53 lymph nodes） among 23 cases esophageal sarcomatoid carcinoma （187 lymph nodes） were observed. Conclusion： The clinical and radiologic features of esophageal sarcomatoid carcinoma overlap with those of other esophageal neoplasms. There are the radiologic imaging changes such as a large, intraluminal, polypoid mass, major filling sublobe defect and pedicle skin flap tumor in esophageal lumen, esophageal lumen extension partly, dissepiment rigidity wall no obviously, etc. Histologically, carcinomatous and sarcomatous components coexist and the biphasic pattern is the key diagnostic feature. However, esophageal sarcomatoid carcinoma has a more favorable prognosis than other malignant esophageal neoplasms. Immunohistochemical staining seems necessary to distinguish these lesions from other esophageal neoplasms.     

Relationship between expression of ER,PR, Her-2, Ki-67 and neoadjuvant chemotherapy effect in breast cancer

Objective： The purpose of the study was to investigate the relationship between the expression of estrogen receptor （ER）, progestogen receptor （PR）, human epidermal growth factor receptor （Her-2）, Ki-67 and the effect of neoadjuvant chemotherapy in breast cancer. Methods： The expression of ER, PR, Her-2 and Ki-67 in 45 breast cancers which received neoadjuvant chemotherapy was detected by immunohistochemistry. Results： The effective rates in ER negative and PR negative groups were higher than those in ER positive and PR positive groups （83.3% vs 59. 4%, 82.4% vs 60.6%）. There was no significant difference of the effective rate between Her-2 overexpressed group and Her-2 non-overexpressed group （81.8% vs 64.1%）, and the same thing happened between Ki-67 negative group and Ki-67 positive group （67.7% vs 63.2%）. Conclusion： In the patients with breast cancer, ER, PR negative ones were more sensitive to neoadjuvant chemotherapy. These patients may get more benefits from chemotherapy. ER, PR could be feasible markers for predicting the effective rate of neoadjuvant chemotherapy.     

The clinical significance of axillary sentinel lymph node biopsy in different clinical stages breast cancer patients after neoadjuvant chemotherapy

Objective： We aimed to study the success and false negative rate of sentinel lymph node biopsy （SLNB） in dif- ferent clinical stages breast cancer patients being carried out with neoadjuvant chemotherapy （NAC）, and the clinical signifi- cance of SLNB, we conducting this trial. Methods： One hunderd and thirty-seven cases were enrolled in this clinical research from March 2003 to March 2007. All of the patients＇ sentinel lymph nodes were detected with 99mTc-Dx and methylene blue. There were 61 patients with stage TI_2NoMo carried SLNB without NAC （group A）, 76 cases were carried out NAC 3-4 cycles before SLNB, including 39 T2_4N0_IMo cases （group B） and 27 T2-4N2_3M0 cases （group C）. The success and false negative rate of SLNB were analysed with chi-square test. Results： In group A, the successful and false negative rate of SLNB were 92.31% （36/39）, 8.57% （3/35）, and in group B and C were 92.31% （36/39）, 8.57% （3/35） and 74.07 % （20/27）, 18.52 % （5/27）, respectively. The successful rate of group C decreased and false negative rate increased significantly compared with group A and B （P 〈 0.05）, but group A and B had no significant difference （P 〉 0.05）. Conclusion： The SLNB can accurately predict lymph node status of axillary lymph node in N0-1 stage patients with NAC, but in N2-3 stage patients the success rate decreased and false rate increased negative significantly.     

The impact of Deta-elemene on Deta-tuDulJn of human hepatoma hepg2 cells

Objective： The aim of this study was to investigate the impact of beta-elemene injection on the growth and beta-tubulin of human hepatocarcinoma HepG2 cells. Methods： Cell proliferation was assessed by MTT assay. Cell cycle distribution was detected by flow cytometry （FCM）. The mRNA expression of beta-tubulin was measured by RT-PCR. West- ern blot analysis was used to determine protein expression of beta-tubulin and the polymerization of beta-tubulin. Results： Beta-elemene injection inhibited HepG2 cells proliferation in a dose- and time-dependent manner; FCM analysis indicated beta-elemene injection induced cell cycle arrested at S phase. RT-PCR and western-blot analysis showed that beta-elemene injection down-regulated beta-tubulin expression at both mRNA and protein levels, presenting a dose-dependent manner. Moreover, beta-elemene injection reduced the polymerization of microtubules in a dose-dependent manner. Conclusion： Beta-elemene injection can inhibit the proliferation of hepatoma HepG2 cells, the mechanism might be partly related to the down-regulation of beta -tubulin and inhibition of microtubular polymerization.     

Morphology and survival of cryopreserved-thawed ovarian tissues after heterotopic autotransplantation

Objective： The aim of our study was to observe the survival and morphological changes of thawed ovarian tis- sues after heterotopic transplantation. Methods： Twenty SPF-SD female rats （5-6 weeks old） were equally randomized into the control group and experimental group. In control group, the freshly isolated ovaries were fixed in formalin. In experimental group, the freshly isolated ovaries were vitrified immediately and cut into thin slices. After stored in liquid nitrogen for 21 days, the tissues of experimental group were rapidly thawed and transplanted into back muscles of rats for 2 or 4 weeks, respectively. After that, all rats in experimental group were sacrificed and the ovarian tissues were collected and fixed in 4% formaldehyde solution. Then the ovarian tissues were stained with HE and observed under the light confocal microscope. Re- suits： With the naked eyes, there was no specific alteration except the size reduction with color changing. Under microscopy, we found normal cortex and medulla in the ovary, and the primordial follicles and follicles in various stages were observed in the cortex. The normal oocytes in ovarian tissues of experimental group were significant decreased than in the control group. Conclusion： The ovarian tissues survive well in experimental group and there is no significant difference in the proportion of follicles between different times （2 and 4 weeks） after grafting. Our results suggest that thawed ovarian tissues could survive after heterotopic transplantation into back muscles of rat models and maintain their morphology and function.     

Clinical implications and prognostic value of five biomarkers in endometrial carcinoma

Objective： The aim was to identify the relationship between ER, PR, P53, Ki-67, PTEN, the association with clinicopathological parameters and the correlation with survival. Methods： We studied 190 cases of primary endornetrial carcinoma in which ER, PR, Ki-67, P53, PTEN antigens were investigated with the use of immunohistochemical methods. To evaluate the correlations among immunohistochemical staining and the age, menopause status, histological type, FIGO stage, grading, depth of invasion, lymph nodes involvement and serum tumor marker. Survival analysis was assessed within single and combined biomarkers types. Results： The percentage of Ki-67 and P53 positive endometrial tumors was signifi- cantly higher in ER negative vs ER positive tumors （both P = 0.000）. The same trend was evident in PR positive and nega- tive group. The percentage of PTEN positive tumors was significantly higher in PR positive versus PR negative tumors （P = 0.021） but was no difference in different ER status. ER and PR status were significant predictors with FIGO staging, grading and recurrence. There was no clear association between PTEN positivity and clinicopathological parameters except more relevance with endometrioid histotype （P = 0.013）. Positive Ki-67 or P53 was found to be strictly related to more aggressive features. There was statistically significant difference in different status of P53 and Ki-67 in survival time. Conclusion： ER and PR positive tumors showed a statistically significant association with better clinical outcome, PR has more significant influ- ence on prognosis. The percentage of positive Ki-67 or P53 was significantly higher in hormone-independent group versus in hormone-dependent group and combined Ki-67 and P53 may have more effect on prognosis in former group.     

Neoadjuvant chemotherapy for triple-negative breast cancer： a meta-analysis with 7168 cases

Objective： The pathological complete response （pCR） rates of neoadjuvant chemotherapy （NAC） in triple-nega- tive breast cancer （TNBC） was reported higher than that in non-TNBC but ranged from 12% to 48%. pCR was reported to be a predictor of long overall survival and exact pCR rate of NAC in TNBC would give us some hints on how to improve outcomes of TNBC patients. The meta-analysis was conducted to estimate the pCR rate of NAC for TNBC through contrasting the pCR rates of TNBC and non-TNBC tumors in NAC. Methods： Studies were selected from the PubMed database and Cochrane Collaboration Library. pCR rates were collected in groups of TNBC and non-TNBC tumors. Review Manager 4.2 was used to perform forest plots and funnel plots. Results： The analysis included 22 studies with 7168 patients, the aggregate pCR rate was 29.5% in TNBC group, which was 17.7% higher than non-TNBC. The summary relative risk （RR） for pCR rate of TNBC group with that of non-TNBC group was 2.55. No obvious statistical heterogeneity and publication bias was detected. Conclu- sion： This meta-analysis demonstrated that NAC showed a higher pCR rate in TNBC than non-TNBC.     

The effect of Jinlong capsule on the immune function for intervened patients with primary liver cancer

Objective： The aim of this study was to evaluate the effect of Jinlong capsule on the immune function for inter- vened patients with primary liver cancer. Methods： Matched the inclusion criteria, 60 patients were selected and randomly divided into two groups. The treatment group had 30 cases treated with Jinlong capsule combined with the transcatheter arterial chemoembolization （TACE）; the control group had 30 cases treated with TACE. Each group was treated 30 days as a cycle, which had completed at least two cycles. Indicators of cellular immune function about the activity of CD3, CD4, CD8, CD4/CD8 and natural killer （NK） cell were detected before and after treatment, then to compare and analysis with each other. Results： Before treatment, the activity of peripheral blood CD3, CD4, CD8, CD4/CD8 and NK cell in the two groups was no significant difference （P 〉 0.05）; after treatment, the activity of CD3, CD4 and NK cell in the treatment group was significantly increased, the ratio of CD4/CD8 increased, and the value of CD8 decreased （P 〈 0.05）, the activity of CD3, CD4 and NK cell in the control group was significantly decreased, the ratio of CD4/CD8 decreased （P 〈 0.05）, and the value of CD8 slightly higher than before treatment （P 〉 0.05）, the difference between the two groups indicated the statistical significance （P 〈 0.05）. Incidence of gastrointestinal reactions, leucopenia, hemoglobin, platelet decline in the treatment group was lower than those in the control group, but without presenting the statistical significance （P 〉 0.05）. Conclusion： Jinlong capsule with hepatic arterial infusion chemotherapy can improve the patients＇ immune function, and reduce the adverse reactions of interventional chemotherapy. Hence, it deserves to be promoted in clinically.     

Clinical observation of platinum-based combined with concurrent three-dimensional conformal radiotherapy in patients with locally advanced non-small cell lung cancer

Objective： The aim of our study was to explore the shortterm efficacy of platinumbased combined with concur rent chemoradiotherapy for locally advanced nonsmallcell lung cancer （NSCLC）. Methods： Between 2006 to 2010, 78 cases of locally advanced NSCLC were enrolled into this trial. All patients were given platinumbased chemotherapy combined with concurrent threedimensional conformal radiotherapy （3DCRT）. Chest CT scans were obtained during endexpiratory and endinspiratory pauses when performing positioning. Image fusion was done after the image data was transferred to treat ment plan system （TPS）. The target volume was delineated on the fusion images. The chemotherapy was given on the first day of radiotherapy. Comprehensive examinations were conducted 46 weeks after concurrent chemoradiotherapy to assess shortterm efficacy. Results： Complete remission （CR） was achieved in 8 cases and partial remission （PR） in 54 cases. The efficiency rate reached 79.5%. Grade IllIV radiation esophagitis occurred in 11.5%. No exit and death cases during treat ment. Conclusion： Concurrent chemoradiotherapy could significantly improve the shortterm efficacy and prolong survival of stage III NSCLC, meanwhile the adverse reactions could be tolerated.     

Spontaneous rupture of the giant gastric stromal tumor （〉 35 cm） as a rare cause of acute abdomen： a case report

A case of spontaneous rupture of giant gastrointestinal stromal tumor （GIST） of stomach causing acute abdomen is described below. A male patient with abdominal mass presented with symptoms and signs of acute abdomen after admitting for 1 day. After preoperative management and evaluation, an exploratory laparotomy was performed, where rupture of a huge tumor in the stomach was found. A subtotal gastrectomy including the mass was performed and the final immunohistochemi- cal examination verified that the neoplasm was a high risk GIST. The postoperative period was uneventful and the patient received treatment with imatinib mesylate, and regular follow-up without recurrence.     

Comparison of two methods for assessing leakage radiation dose around the head of the medical linear accelerators

Objective： The aim of this study was to measure the leakage by two methods with ion chamber and ready packs film, and to investigate the feasibility and the advantages of using two dosimetry methods for assessing leakage radiation around the head of the linear accelerators. Methods： Measurements were performed using a 30 cm^3 ion chamber; the gantry at 0°, the X-ray head at 0°, the field size at between the central axis and a plane surface at a FSD of 100 as a reference, a series of concentric circles having radii of 50, 75, and 100 cm with their common centre at the reference point. The absorbed dose was measured at the reference point, and this would be used as the reference dose. With the diaphragm closed, the measurements were taken along the circumference of the three circles and at 45~ intervals. Results： Leakage radiations while the treatment head was in the vertical position varied between 0.016%-0.04%. With the head lying horizontally, leak- age radiation was the same order magnitude and varied between 0.02%-0.07%. In the second method, the verification was accomplished by closing the collimator jaws and covering the head of the treatment unit with the ready pack films. The films were marked to permit the determination of their positions on the machine after exposed and processed. With the diaphragm closed, and the ready packs films around the linear accelerator the beam turned on for 2500 cGy （2500 MU）. The optical den- sity of these films was measured and compared with this of the reference dose. Leakage radiation varied according to the film positions and the magnitude of leakage was between 0.005%-0.075%. Conclusion： The differences between the values of the leakage radiation levels observed at different measurement points do not only reflect differences in the effective shielding thickness of the head wall, but are also related to differences in the distances between the target and the measurement points. The experimental errors involved in dosimetric measurement also contribute to such differences.     

Study of the Dextran-DTPA-Gd at rabbit popliteal fossa lymph node metastasis from thigh transplanted tumor with interstitial magnetic resonance lymDhoqraDhv

Objective： The aim of the study was to investigate the developing situation of the interstitial magnetic resonance （MR） lymphoid contrast agent Dextran-DTPA-Gd through the rabbit popliteal fossa lymph node metastasis from thigh VX2 transplanted tumor injection to show targeting enhanced metastatic lymph nodes and lymphatics. Methods： VX2 tumor was transplanted to the right hind limb quadriceps of 12 healthy New Zealand rabbits and the left side as a contrast. Eight rabbits had homonymy popliteal lymph node metastasis after 1 month through 3.0 GE MRI and they were later injected with lym phatic targeting contrast agent Dextran-DTPA-Gd 0.4 mL （3.96 x 10^-3 tool/L） through bilateral hindlimb toe web respectively. Enhanced MR images were obtained with interval 10 min, 15 min, 20 rain, 25 min, 30 rain, 35 min, 40 rain, 45 rain, 50 min, 55 min, 60 min, 2 h, 4 h, and 24 h. The signal intensities before and after enhancing were measured to calculate the enhanc- ing rates （E%） of popliteal lymph node and the popliteal lymph node signal intensity-time curves were drawn to observe the development of cancer metastasis lymph nodes and lymphatics and to compare the differences of interval sides. Results： Ten minutes after injected into the rabbit＇s bilateral hindlimb toe web, we could see hind lymphatic and popliteal lymph nodes were strengthened significantly and evenly without blood vessels developing. The signal reached a peak after 35 rain with E% to 315%, which decreased to 205% after 4 h and would be undifferentiated with the surrounding tissues after 24 h. Sta- tistical analysis was made to popliteal lymph node enhancement rate. It was considered statistically significant as long as P 〈 0.05. The tumor-side popliteal lymph node manifested as coarse and irregular shape, lymphatic vessels tortuous dilated and lymphatic chain incomplete as a result of tumor infection. Conclusion： Dextran-DTPA-Gd is specific to lymphoid tissue development. It can targeting display regional lymphatic drainage concretion and the morphology of normal and cancer cells metastasis lymph nodes rapidly.     

A dosimetric comparison between 3D-Conformal radiation therapy and intensity modulated radiation therapy plans in the treatment of posterior fossa boost in children with high risk medulloblastom

Objective： The work is a comparative study between two modalities of radiation therapy, the aim of which is to compare 3D conformal radiation therapy （3D-CRT） and intensity modulated radiation therapy （IMRT） in treating posterior fossa boost in children with high risk medulloblastorna; dosimetrically evaluating and comparing both techniques as regard target coverage and doses to organs at risk （OAR）. Methods： Twenty patients with high risk medulloblastoma were treated by 3D-CRT technique. A dosimetric comparison was done by performing two plans for the posterior fossa boost, 3D-CRT and IMRT plans, for the same patient using Eclipse planning system （version 8.6）. Results： IMRT had a better conformity index compared to 3D-CRT plans （P value of 0.000）. As for the dose homogeneity it was also better in the IMRT plans, yet it hasn＇t reached the statistical significant value. Also, doses received by the cochleae, brainstem and spinal cord were significantly less in the IMRT plans than those of 3D-CRT （P value 〈 0.05）. Conclusion： IMRT technique was clearly able to improve conformity and homogeneity index, spare the cochleae, reduce dose to the brainstem and spinal cord in comparison to 3D- CRT technique.