Objective To establish a novel clinical application process of the optical surface monitoring system(OSMS)guided volumetric modulated arc therapy(VMAT)for total body irradiation(TBI),and to assess the accuracy and effectiveness of OSMS in inter-fractional auxiliary positioning before radiotherapy and real-time monitoring of intra-fractional motion during radiotherapy.Methods A retrospective analysis was conducted on 15 leukemia patients who underwent OSMS-guided VMAT-TBI before hematopoietic stem cell transplantation.CT simulation positioning was performed,and the whole-body image data which were collected in head-first supine position(HFS)and feet-first supine position(FFS)were transmitted to the treatment planning system for image registration,multicenter VMAT planning and dose verification.The prescription dose was 800 cGy in 4 fractions twice daily.OSMS was used to assist positioning before delivery,and CBCT was used for position verification.During treatment,OSMS was used for monitoring.The intra-fractional error monitored by OSMS in real time was obtained by analyzing the offline log files.Results The mean dose and coverage of the target area in HFS plan were(905.4±19.0)cGy and 93.0%±2.8%.The mean doses to lung and kidney were(603.7±55.7)cGy and(600.4±49.6)cGy,respectively,and the maximum dose to the lens was(393.9±58.9)cGy.The mean dose and coverage of the target area in FFS plan were(888.5±58.9)cGy and 94.0%±3.2%;and the maximum dose at the junction was(1148.9±72.9)cGy.Fractional treatment delivery time was(75.1±15.1)min.OSMS-assisted positioning was carried out before delivery,and the total deviations of CBCT three-dimensional vector in translational and rotation directions were(2.71±1.96)mm and 0.91°±0.90°,respectively.The three-dimensional vector deviation of the intra-fractional motion amplitude in translational direction monitored by OSMS during the treatment was(1.95±1.88)mm,of which the deviation within 1 mm accounted for 57.5%,79.7%and 62.1%in longitudinal,lateral and vertical directions,respectively.The three-dimensional vector deviation in rotation direction was 0.76°±0.72°,of which the deviation within 1°accounted for 93.1%,85.7%and 94.3%in rotation,pitch and roll directions,respectively.Conclusion VMAT simplifies TBI process,while improving target coverage and organs-at-risk sparing.The use of OSMS can reduce positioning errors,especially rotation errors.In order to ensure the accurate implementation of TBI and the safety of patients,it is necessary to use OSMS for auxiliary positioning and intra-fractional position monitoring.

Objective:To investigate the protection of Active Breathing Coordinator(ABC)technique for heart and its substructures in radiotherapy for left breast cancer.Methods:A total of 50 patients with left breast cancer who underwent radiotherapy in our department were retrospectively selected,and treatment plans with intensity modulated radiotherapy(IMRT)were designed on the images of ABC combined with deep inspiration breath hold(ABC-DIBH)computed tomography(CT)and free-breathing(FB)CT,respectively.The dose parameters of the organ at risks(OARs)of heart and its substructures,including left ventricle(LV),left atrium(LA),right ventricle(RV),right atrium(RA),left main coronary artery(LMCA),left anterior descending coronary artery(LAD),left circumflex coronary artery(LCX)and right coronary artery(RCA),were compared between the two conditions.Results:Compared with FB,the dose of 2%volume(D2),the mean dose(Dmean),the percent volumes covered by different doses(V30,V20,V10,V5)decreased respectively 32.91%(absolute reduction of 1279.11 cGy),36.12%(195.94cGy),58.95%(2.8%),54.32%(3.58%),50.14%(5.56%)and 46.22%(9.67%)of heart under ABC-DIBH condition,and the differences were significant(t=10.28,12.81,9.16,10.28,12.82,12.24,P＜0.01),respectively.In addition,the Dmean values of LV,LA,RV,RA,LMCA,LAD,LCX and RCA decreased by 37.64%(absolute reduction was 285.92 cGy),15.38%(23.68 cGy),34.12%(118.93cGy),9.72%(12.52 cGy),22.17%(47.99 cGy),31.81%(820.63 cGy),16.51%(34.72 cGy)and 14.86%(34.11cGy)under ABC-DIBH condition,respectively,the differences were significant(t=9.50,3.71,6.20,8.65,3.18,10.92,4.26,6.71,P＜0.05).Conclusion:ABC technique can greatly reduce the received doses of heart and its substructures by extending the distance between the heart and the target region with DIBH,thus can form a very effective protection for the heart and its substructures.In addition,it can eliminate the dynamic variation of target location of breast cancer caused by respiratory,and avoid a series of problems,such as target missing,overexposure on normal tissue,and dose deviation.

Objective:To compare the dosimetric differences between active breathing coordinator (ABC) and Catalyst for respiratory gating after breast conserving surgery for left breast cancer.Methods:Data of 48 female patients with left breast cancer after breast conserving surgery admitted to the Radiotherapy Department of Shenzhen People′s Hospital from November 2020 to August 2021 were retrospectively selected. They were randomized to receive dynamic intensity modulated radiotherapy (IMRT) plans with ABC or Catalyst. The dosimetric differences in targets and organs at risk between the two groups were analyzed.Results:Comparison of the two respiratory gating IMRT plans revealed no statistically significant differences ( P > 0.05) in D90%, D98%, Dmax, Dmean, conformity index (CI), homogeneity index (HI), and monitor unit parameters in the target volume, (i.e., chest wall), as well as the ipsilateral lung and heart under the deep inhalation breath hold (DIBH) mode. The Dmean, Dmax, and D2% of the left anterior descending coronary artery (LAD) in the Catalyst group were better than those in the ABC group [(1 047.72 ± 1 401.84) vs. (454.48 ± 206.26), (1 619.28 ± 809.05) vs.(1 068.53 ± 419.63), (1 405.85 ± 798.30) vs. (1 016.54 ± 592.00) cGy], with statistically significant differences ( t= -2.07, -3.18, -2.07, P<0.05). Conclusions:Both ABC and Catalyst respiratory gating systems meet the requirements for clinical treatment, with the latter more effective in reducing the exposure dose of LAD.

Novel coronavirus pneumonia (NCP), known as COVID-19 for short, is a new infectious disease that spreads rapidly. Since the outbreak of the epidemic, the global epidemic situation is still grim. It is necessary for a comprehensive grade triple-A hospital to strictly control the transmission risk in the hospital and ensure the life and health safety of medical staff, other patients and accompanying staff, in addition to fulfilling its responsibility of treating COVID-19 patients. In this context, unprecedented challenges have been posed to the routine work flow of the hospital, including personnel management, system construction, supply and logistics support, and infection control. The paper summarizes the experience in hospital logistics support management, aiming at exploring strategies for coping with the COVID-19 epidemic.

Objective:To explore the value of laparoscopic and endoscopic cooperative surgery with the patient lying on supine position under general anesthesia in the operation of type I Mirizzi syndrome with choledocholithiasis.Methods:From Jan 2018 to Jan 2020, 53 cases of Mirizzi syndrome with choledocholithiasis undergoing laparoscopic and endoscopic cooperative surgery (preLC+ ERCP+ EST) at the Second Affiliated Hospital of Kunming Medical University were retrospectively analyzed.Results:53 patients successfully underwent LC without conversion to open surgery, and 2 patients failed in ERCP + EST attempt, with a success rate of 96.2%. One patient developed pancreas pseudocyst as a result of post-operative hemorrhagic necrotizing pancreatitis. Two patients suffered from chronic pancreatitis. Three patients complaining postoperative upper abdominal discomfort were finally diagnosed as stump cystic duct inflammation by MRCP, and no abnormalities were found in the follow-up of the remaining cases.Conclusion:Laparoscopic and endoscopic cooperative surgery in the treatment of patients with type I Mirizzi syndrome combined with choledocholithiasis is minimally invasive and effective.