After COVID -19, patients, medical workers and the whole society in COVID -19 were faced with the challenge of how to quickly return to normal life. Patients cured in COVID -19 would face mental or psychological barriers, or be discriminated against, or face problems such as overweight of local epidemic prevention policies. The front-line medical personnel experienced job burnout and a variety of mental and psychological disorders, with some even developing physical symptoms. During the epidemic, ordinary people were in a state of psychological stress, education, production and economic activities were affected, and the incidence of mental or psychological disorders increases. It was necessary to provide COVID -19 patients with mental health monitoring and counseling. Give professional guidance to front-line medical staff, arrange rotation reasonably, and pay attention to their mental health status. Local governments should strictly implement the national epidemic prevention system, formulate epidemic prevention policies with humanistic care, actively publicize epidemic related knowledge and safeguard the rights and interests of the people.

To study an automatic plan(AP) method for radiotherapy after breast-conserving surgery based on TiGRT system and and compare with manual plan (MP). The dosimetry parameters of 10 patients and the evaluation of scoring table were analyzed, it was found that the targets dose of AP were better than that of MP, but there was no statistical difference except for CI, The V5, V20 and V30 of affected lungs and whole lungs in AP were lower than all that in MP, the Dmean of hearts was slightly higher than that of MP, but the difference was not statistically significant, the MU of AP was increase by 16.1% compared with MP, the score of AP evaluation was increase by 6.1% compared with MP. So the AP could be programmed and automated while ensuring the quality of the plan, and can be used to design the plans for radiotherapy after breast-conserving surgery.
Breast Neoplasms/surgery* ; Female ; Humans ; Mastectomy, Segmental ; Organs at Risk ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; Radiotherapy, Intensity-Modulated

After COVID -19, patients, medical workers and the whole society in COVID -19 were faced with the challenge of how to quickly return to normal life. Patients cured in COVID -19 would face mental or psychological barriers, or be discriminated against, or face problems such as overweight of local epidemic prevention policies. The front-line medical personnel experienced job burnout and a variety of mental and psychological disorders, with some even developing physical symptoms. During the epidemic, ordinary people were in a state of psychological stress, education, production and economic activities were affected, and the incidence of mental or psychological disorders increases. It was necessary to provide COVID -19 patients with mental health monitoring and counseling. Give professional guidance to front-line medical staff, arrange rotation reasonably, and pay attention to their mental health status. Local governments should strictly implement the national epidemic prevention system, formulate epidemic prevention policies with humanistic care, actively publicize epidemic related knowledge and safeguard the rights and interests of the people.

Objective:To explore the feasibility of the clinical implementation of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans with 6MV photon on two Elekta Linacs (Versa HD and Synergy) after beam matching.Methods:The images of 12 patients with nasopharyngeal carcinoma, central lung cancer and prostate cancer were randomly selected, and the IMRT and VMAT plans were designed. Two different dose tools of ionization chamber and three-dimensional detector ArcCheck were used to verify the individualized radiation treatment of 6MV photon beams on two Linacs and compare the differences.Results:The deviations between the doses of two Linacs (Versa HD and Synergy) measured by the ion chamber and treatment planning system were (0.32±1.32)% and (0.54±1.29)%. The differences of all plans were within the range of ±3%, and the deviations of the point dose between two Linacs were within the range of ±2% with no statistical significance (both P>0.05). The γ analysis of verification using ArcCheck showed that the passing rates of all plans under the 2mm/3% and 3mm/3% with 10% threshold conditions were over 95%, respectively. The average differences between two Linacs were 0.19%(2mm/3%) and 0.09%(3mm/3%). Conclusions:The results of performing IMRT/VMAT plans on two Linacs meet the clinical requirements and the differences between two Linacs are small. Hence, the same plans can be implemented interchangeably on different Linacs.

Objective:To explore the beam performance of GTR 360° PBS dedicated nozzle for IBA Proteus Plus proton system and evaluate the beam characteristics of PBS during acceptance test procedure (ATP) to meet the precision and safety requirements of clinical treatment.Methods:According to the requirements of acceptance tests, the beam tests of PBS mainly included: test of integrated depth dose (IDD), test of maximum field size at the maximum and minimum ranges, field uniformity and informative PBS tests for the GTR 360°, test of lateral dose uniformity in a single field uniform dose in a cube, test of longitudinal dose uniformity in a single field uniform dose in a cube, and test of monitor unit reproducibility and proportionality.Results:The maximum deviation measured of range, fall back accuracy and distal fall-off was 0.03 g/m 2, 0.01 g/m 2 and 0.078 g/m 2, respectively. Maximum field size at the maximum and minimum ranges was 30.2 cm×40.2 cm and 30.1 cm×40.1 cm, respectively. During the different gantry angles and ranges, the lowest γ passing rate of a pattern plan was 97%, the maximum deviation of the centrical beam spot size at the X and Y axes was -0.16 mm and -0.21 mm, and the worst symmetry was 0.80%. Compared with the centrical beam spot, the maximum size deviation of the other beam spots was 0.11 mm and 0.14 mm at the X and Y axes, and the maximum position accuracy deviation of the beam spot was 0.60 mm and 0.43 mm at the X and Y axes. The maximum deviation of lateral dose uniformity at at the X and Y axes was 0.55% and 0.80% in the high energy region, and 0.6% and 0.75% in the low energy region. The maximum deviation of longitudinal dose uniformity was 0.79% in the high energy region, and 2.22% in the low energy region. The monitor unit (MU) reproducibility factor was 0.106% and the maximum proportionality deviation was 0.67%. Conclusion:The dedicated nozzle of PBS has passed all the beam performance acceptance tests, which meet the requirements of all parameters, and the whole system yields relatively high accuracy, repeatability and good stability.

Flash radiotherapy is a kind of radiotherapy method using ultra-high dose rate radiation. Compared with the traditional dose rate radiotherapy, it has unique radiobiological advantages. In this paper, the principle of flash radiotherapy, the process and results of biological experiments are summarized. At the same time, the advantages and challenges of flash radiotherapy are analyzed, and the future clinical application is prospected.
Radiotherapy/methods* ; Radiotherapy Dosage ; Technology

Objective: To study the dosimetric characteristics and plan quality of PTV-based intensity modulated proton radiotherapy (IMPT) and volumetric-modulated arc therapy (VMAT) plans for prostate cancer, so as to provide a reference for clinical application. Methods: A total of 10 prostate cancer cases were included in this retrospective study. IMPT and RapidArc plans were designed by RayStation and Eclipse TPS based on PTV, respectively. For each case, IMPT plans were generated using multiple field optimization (MFO) technique with two parallel-opposed lateral fields, whereas RapidArc plans were generated using double-arc technique (two full arcs). Final dose calculation of IMPT was conducted by pencil beam(PB) and Monte Carlo (MC) algorithm, respectively, with adopted data model from the pencil beam scanning (PBS) proton therapy system of IBA Protues Plus(IBA Group, Belgium); The data model originated from the linear accelerator of Varian Clinac iX (Varian Medical Systems, America) was used for RapidArc plans. Dosimetric parameters of DVH and dose distribution were used to compare the dose differences in targets and organs at risk (OARs) between these two treatment techniques. Results: For targets, HIs of PB-IMPT and MC-IMPT were slightly better than that of RapidArc , but CI of IMPT was slightly lower than that of RapidArc; D_1% of PB-IMPT was significantly better than those of MC-IMPT and RapidArc (Z=-2.805, -2.803, P<0.05). PB-IMPT and MC-IMPT achieved better protection than RapidArc on rectum V₃₀(Z=-2.191, -1.988, P<0.05)and D_mean(Z=-2.599, -2.497, P<0.05), bladder V₃₀(Z=-2.701, -2.701, P<0.05), V₄₀(Z=-2.395, -2.395, P<0.05)and D_mean(Z=-2.701, -2.701, P<0.05). There was no significant difference between PB-IMPT and MC-IMPT plans for prostate cancer, except for the D_1% [(73.86±67.34) Gy vs.(75.45±2.01) Gy] (RBE) and HI [(0.040±0.010) vs. (0.058±0.020)] of the target. Conclusions Both techniques can meet the clinical requirements, but IMPT showed significant dosimetric advantages compared with RapidArch by reducing the dose to OARs and improving the plan quality.

Objective To explore the feasibility of the volume modulated arc therapy ( VMAT) auto-planning based on template library ( TL). Methods VMAT plans of 68 patients diagnosed with postoperative rectal cancer in Eclipse system were retrospectively selected. The prescription dose was 50 Gy/25F. In 19 patients, the feature values of target and organs at risk were extracted as the vectors. The final optimized restricted conditions were saved as the TL. Then, the plans of 15 rectal cancer patients (10 cases from TL and 5 outside TL) were automatically optimized. According to the multi-dimensional vector similarity principle, the similarity parameter αwas defined. The designed program automatically selected the optimal-object template in an in-house software developed with Matlab. The dosimetric parameters of the auto-optimized plans with the optimal-object template (ATP) and the clinical plan (CP) were compared by the paired t-test. The changes in the dosimetric parameters and similarity parameter α were statistically compared by Pearson′s correlation analysis. The linear fitting of the dosimetric parameters with α was used by least squares method to explore the tendency of the ATP dosimetric parameters relative to CP. Results The dosimetric parameters of ATP for 13 cases were slightly worse than those of CP. The conformal index (P=0. 004), heterogeneous index (P= 0. 015),V40(P= 0. 003) and mean dose (P= 0. 022) of the intestine significantly differed. The α values of these 13 cases were 2. 67,2. 60,2. 60,2. 49,2. 67,2. 74,2. 72,2. 48, 2. 53,2. 86,2. 68,2. 56 and 2. 63. The α value was significantly correlated with the V40 or mean dose of the bladder (r= 0. 649 and 0. 603,P= 0. 016 and 0. 029).Along with the increase of α value ,V40 and mean dose of the intestine for ATP were gradually deteriorated than those of CP . The remaining dosimetric para-meters of ATP were close to or superior to those of CP. Conclusions The results of ATP are slightly worse than those of CP, whereas can satisfy the clinical requirements. The TL, the quality of TL and ATP remain to be further optimized.

Objective To explore the application of bundle management in enhanced recovery after surgery (ERAS) on liver transplantation.Methods The multidisciplinary team of West China Hospital of Sichuan University discussed the program of ERAS on liver transplantation in 2016,and implemented this program in July 2016.A retrospective analysis was made on 220 liver transplant patients who were admitted to West China Hospital of Sichuan University in the period from Jan.2015 to Mar.2017.According to the inclusion and exclusion criteria,there were 104 patients in traditional group and 92 patients in ERAS group.The clinical indicators during and after surgery were compared between the two groups,and the applied value of ERAS on liver transplantation was analyzed.Results As compared with the traditional group,the patients in ERAS group had advantages in operative time,blood loss,postoperative stay in intensive care unit (ICU),transfusion volume in ICU,endotracheal intubation time and total hospitalization time,with significant difference between the two groups (P＜0.05).Meanwhile readmission and mortality rate after one month in ERAS group was not increased.Conclusion The bundle management in ERAS on liver transplantation of West China Hospital of Sichuan University can improve the prognosis of liver transplant patients.

Objective To study the difference of the constructed doses between electronic portal imaging device (EPID) and dynalogs files of linac for in vivo phantom dosimetry.Methods Twelve pelvic patients treated with volumetric modulated arc therapy (VMAT) plans were selected and the information of each plan was copied to theCheese phantom to recalculate the doses before delivered on Varian RapidArc Linac.TheCheese phantom was placed on the isocenter and the electronic portal image (EPI) formed by the EPID was sent to EPIgray software to reconstruct the actual delivered doses.Meanwhile,dynalogs files were respectively imported to the Mobius software to reconstruct the actual delivered doses too.The point dose in the center of each VMAT plan (the center of the effective sensitive volume of ionization chamber) was measured by the A1SL ionization chamber.At the same time,the dose of sensitive volume of ionization chamber from treatment planning systcm (TPS) was recorded.Results The relative deviation between the dose from TPS and the measurement results by the ionization chamber was 1.13％.The difference between the reconstructed doses of EPID-based or the dynalogs file-based with the measurement results by the ionization chamber was not statistically significant (P ＞ 0.05).Conclusions The two methods of dose reconstruction can provide reference for in vivo dosimetry of VMAT.