On the basis of data collected from an investigation on the variety structure of drug consumption in the cities and rural areas of China, we analyse the developing trend of the variety structure of drug consumption in China and elaborate the differences between urban and rural areas and between China and overseas.

Objective:To research the rule of melatonin nasal absorption.Methods: The stability of melatonin in rat nasal wash was studied, after that the in situ rat nasal recirculation methods were used as experimental animal model to study the rule of melatonin nasal absorption.Results:Melatonin was stable in rat nasal wash, its absorption in nasal cavity accorded with first order kinetic equation. The absorption rate constants did not vary with melatonin concentrations.Conclusion:The mechanism of melatonin nasal absorption is passive diffusion, the average absorption rate constant is 1.054?10 -2 min -1 .

Objective To investigate the correlation between survival motor neuron (SMN) gene deletion and Chinese patients with sporadic amyotrophic lateral sclerosis (SALS).Methods A total of 141SALS patients and 134 unrelated controls were recruited from the Chinese population.Polymerase chain reaction (PCR) and restriction fragment length polymorphisro (RFLP) analysis were performed to screen SMN gene deletion.Frequencies of deletion were coropared by Chi-square test.Results Four patients and 3 controls were detected to have horoozygous SMN2 deletion.The frequencies of SMN2 deletion were 2.84%(4/141) and 2.24% (3/134), respectively, which was not significantly different (χ2= 0.0001, P =1.000).No subjects were found to have homozygous SMN1 deletion.Condusion There is no correlation between SMN gene deletion and Chinese patients with SALS.

Objective To establish a loop-mediated isothermal amplification method for detection of Campylobacter jejuni.Methods Six sets of primers were designed to recognize Campylobacter jejuni specific gene hipO.One was selected as the optimal primer and its specificity and sensitivity to Campylobacter jejuni were evaluated by LAMP reaction in 60 minutes at 62℃.Results The results recorded by the turbidity meter showed that the sensitivity of LAMP with a detection limit of 6.97×102 copies/μl was ten times that of PCR.Conclusion LAMP is a potential and valuable method of detection of Campylobacter jejuni due to its rapidity,simplicity,low cost and accuracy.It is especially suitable for grass-roots medical units.

Objective To evaluate the effect of setup errors upon the target area and the organs at risk (OAR) during radiotherapy for prostate cancer.Methods Twelve prostate cancer patients receiving treatment in the recent 1 year were randomly recruited in this study.The position of each patient was verified by using cone beam CT (CBCT) for 6-10 times during the treatment.In treatment planning system (TPS),the isocenter position was moved along the setup errors with averaging error value (Plan_A) and each CBCT value (Plan_F).The dose distribution was recalculated without changing the beam setting,weight factors and monitor units (MUs).The dose difference was statistically compared between the simulation and original plans (Plan_O).Results For clinical target volume (CTV) D95,there was a significant difference between Plan_A and Plan_O (P =0.008),whereas no significant difference was observed between Plan_F and Plan_O.There were significant differences between Plan_F and Plan_O,Plan_A and Plan_O (P=0.004,and 0.041) for the planned target volume (PTV) D95.For OAR,rectal V60,Dmax,left femoral V20,Dmax and right femoral Dmax significantly differed between Plan_F and Plan_O (P=0.026,0.015,0.041,0.049,0.003).However,only left femoral Dmax significantly differed between Plan_A and Plan_O (P=0.045).The movement in the superior-inferior (SI) direction was significantly correlated with the changes in the rectal V40,V50 and V60 and PTV D95 (r=-0.785,-0.887,-0.833,0.682).The movement in the anterior-posterior (AP) direction was significantly associated with the variations in the bladder V20,V30,V40,V50 and V60(r=-0.945,-0.823,-0.853,-0.818,-0.774).The evaluation indexes of all normal tissues in the re-plan could meet the clinical requirements.However,the volume of target prescription volume had different levels of deficit,and the deficit of Plan_F was greater than that of Plan_A.Conclusions The simulation results of averaging into the TPS underestimates the effect of daily setup errors on the dose distribution.The effect of setup errors on the dose distribution in target area is greater than that of normal tissues.Y-direction errors are more likely to cause the variations of the rectal and PTV dose,and the errors in the z-direction are inclined to cause the changes in the bladder dose.

Objective To analyze the correlation between treatment time and radiotherapy plan of deep inspiration breath-hold (DIBH) technique for the whole breast irradiation (WBI) in the left breast cancer after breast-conserving surgery,verify the inter-fractional reproducibility of radiotherapy,observe the heart location and dosimetric changes and calculate the effect of DIBH upon the WBI setup error after the surgery.Methods We prospectively enrolled 15 patients with left breast cancer undergoing WBI after breast-conserving surgery,who met the requirement of D1BH.Treatment time was recorded,its correlation with the number of field and monitor unit was analyzed.Inter-fractional setup errors and PTV delineation were calculated using cone beam CT (CBCT).The accuracy of the position and dose of the heart during radiotherapy was verified by the imaging fusion of CBCT and CT images.The variables among groups were analyzed by non-parametric Firedman test.Results The average treatment time of DIBH radiotherapy was 4.6 minutes.The treatment time was correlated with the maximal and total number of sub-fields and total monitor units.During DIBH treatment,the mean cardiac displacement volume was 19.1 cm3(3.8％).The mean cardiac dose difference between CBCT and planning CT was 5.1 cGy,and there was no significant difference in the heart V5-V30.The mean inter-fractional system setup error (∑) and random setup error (σ) in the left-right (x),superior-inferior (y) and anterior-posterior (z) direction were ∑x 1.9 mm,∑y 2.1 mm,∑z 2.0 mm,σx 1.3 mm,σy 1.3 mm,σz 1.4 mm,respectively.The corresponding minimal margins for setup error were 5.7 mm,6.2 mm and 6.0 mm,respectively.Conclusion DIBH for WBI after breast-conserving surgery does not significantly prolong the treatment time.Treatment time is related to treatment plan.DIBH yields high inter-fractional reproducibility and protects the heart.

Objective To retrospectively analyze the setup error in radiotherapy of somal tumors and body metastases using the ExacTrac X-ray portal image,and to evaluate the feasibility and effectiveness of 6D setup error correction in body radiotherapy.Methods The translational and rotational setup errors were calculated by registering the bony structures on the ExacTrac X-setup images to that of the digitally reconstructed setup images,and the corresponding residual errors were calculated together.Results The translational and rotational setup errors in the x (left-right),y (superior-inferior),z (anterior-posterior) and Rx (sagittal),Ry (transverse),Rz (coronal) directions were(2.27±2.02) mm,(4.49±2.52) mm,(2.27± 1.37) mm and (1.02 ± 0.73) °,(0.67 ± 0.68) °,(0.76 ± 0.84) °,respectively.The residual translational and rotational setup errors in the x(r),y(r),z(r) and Rx(r),Ry(r),Rz(r) directions were(0.27±0.48)mm,(0.37±0.45)mm,(0.22±0.30)mm and (0.17±0.33)°,(0.14±0.34)°,(0.16± 0.28) ° respectively.Conclusions Besides the translational setup errors,a certain amount of rotational setup errors exist in radiotherapy of somal tumors and body metastases.By using the 6D setup error correction of the ExacTrac system,a translational less than 0.4 mm and rotational setup errors less than 0.2° could be achieved.

Objective To quantify the setup errors measured with kV cone-beam CT (CBCT) using breast board with or without a thermoplastic head mask in breast cancer patients who received whole breast and supraclavicular nodal region irradiation.Clinical target volume (CTV) to planning target volume (PTV) in 3 directions were also calculated.Methods The study included thirty patient receiving both whole breast and supraclavicular nodal region irradiation on Elekta Versa HD linear accelerators (Elekta Oncology Systems,Crawley,UK) between June 2016 and January 2018.The setup error data were retrospectively analyzed.All the patients were immobilized in the supine position on a breast board system (Carbon fibre breast board,Civco,Iowa,USA) with both arms raised.Twenty of the patients added an extra thermoplastic head mask to immobilize the neck.A CBCT scan was taken before treatment at the first 3 to 5 fractions and then once every week.Registration with the planning CT was performed and adjusted to match the target volume of the supraclavicular nodal region and the cervical vertebra by experienced medical staff,the position of the arms and the breast were also considered.For all patients the couch shifts in left-right (x),superior-inferior (y),anterior-posterior (z) were recorded.Statistical analysis included two-tails significance tests (t-Student and Manne-Whitney test for means,x2 test for variances).Population of the two groups was compared in terms of distribution of the mean shift (systematic error) and their standard deviations (random error).Van Herk's setup margin defined as MPTV =2.5Σ + 0.7δ was calculated in patients with or without mask immobilization.Results Altogether,56 images and 109 images were acquired in breast board only group and head mask group,respectively.Shifts of the breast board only group and the head mask group in x,y,z were 0.212±0.174 cm vs.0.272±0.242 cm (P=0.070);0.364±0.246 cm vs.0.242±0.171 cm (P=0.001);0.423±0.302 cm vs.0.364±0.269 cm (P=0.204).Proportion of the shift less than 5 mm in the breast board only group and the head mask group were 91.07％ vs.85.32％ (P=0.294);67.86％ vs.89.91％ (P=0.001);67.86％ vs.74.31％ (P=0.381).The CTV to PTV margin in x,y,z were 0.645 cm,0.981 cm,1.317 cm in breast board only group and 0.873 cm,0.709 cm,0.961 cm in head mask group,respectively.Setup error in the x direction was significantly correlated with BMI (P=0.001).Conclusions For the alignment and immobilization of patients who received whole breast and supraclavicular nodal region irradiation,using a breast board in combination of a thermoplastic head mask may significantly help to reduce the shift variance in superior-inferior direction compared to using breast board only.The anterior-posterior error is relatively large,other immobilization device or patient alignment methods are needed to be further explored to improve the accuracy.

With aligned MR registration, the MR-Linac provides superior soft tissue resolution for prostate cancer. No fiducial markers or electromagnetic transponders insertion is needed to guarantee high-precision radiotherapy. The highly-recommended Adapt-To-Shape (ATS) workflow can resolve all the problems encountered during prostate cancer radiotherapy, including prostate volume changes and adjacent organs motion, both inter-fractionally and intra-fractionally. With all the above advantages, MR-Linac performs outstandingly than conventional linac in prostate cancer RT delivery, and probably helps us to reduce the CTV-PTV margin safely in the near future. Nevertheless, it is difficult to implement the ATS workflow in clinical practice. In this article, the standard ATS workflow for prostate cancer was summarized based on our own experience.

Objective:To investigate the workflow, efficacy and safety of MR-Linac in liver malignancies.Methods:Clinical data of 15 patients with hepatocellular carcinomas (HCC) or liver metastases treated with MR-Linac between November 2019 and July 2021 were retrospectively analyzed. The workflow of MR-Linac was investigated and image identification rate was analyzed. Patients were followed up for response and toxicity assessment.Results:Fifteen patients (6 HCC, 8 liver metastases from colorectal cancer, 1 liver metastasis from breast cancer) were enrolled. A total of 21 lesions were treated, consisting of 10 patients with single lesion, 4 patients with double lesions and 1 patient with triple lesions. The median tumor size was 2.4 cm (0.8-9.8 cm). The identification rate for gross tumor volume (GTV) in MR-Linac was 13/15. Although GTV of two patients were unclearly displayed in MR-Linac images, the presence of adjacent blood vessel and bile duct assisted the precise registration. All the patients were treated with stereotactic body radiation therapy (SBRT). For HCC, the median fraction dose for GTV or planning gross tumor volume (PGTV) was 6 Gy (5-10 Gy) and the median number of fractions was 9(5-10). The median total dose was 52 Gy (50-54 Gy) and the median equivalent dose in 2 Gy fraction (EQD 2Gy) at α/ β= 10 was 72 Gy (62.5-83.3 Gy). For liver metastases, the median fraction dose for GTV or PGTV was 5 Gy (5-10 Gy) and the median number of fractions was 10(5-10). The median total dose was 50 Gy (40-50 Gy) and the median EQD 2Gy at α/ β=5 was 71.4 Gy (71.4-107.1 Gy). At 1 month after SBRT, the in-field objective response rate (ORR) was 8/13 and the disease control rate was 13/13. At 3-6 months after SBRT, the in-filed ORR was increased to 6/6. During the median follow-up of 4.0 months (0.3-11.6), 4-month local progression-free survival, progression-free survival and overall survival were 15/15, 11/15 and 15/15, respectively. Toxicities were mild and no grade 3 or higher toxicities were observed. Conclusions:MR-Linac provides a platform with high identification rates of liver lesions. Besides, the presence of adjacent blood vessel and bile duct also assists the precise registration. It is especially suitable for liver malignancies with promising local control and well tolerance.