Objective·To compare the effects and complications of carbon dioxide laser laryngectomy and open partial laryngectomy in the treatment of laryngeal carcinoma.Methods·Clinical data of 101 patients with stage Ⅰ-Ⅲ laryngeal squamous cell carcinoma admitted to Renji Hospital,Shanghai Jiao Tong University School of Medicine from January 2013 to January 2018 were selected and divided into open surgery group and minimally invasive group according to different surgical methods.The open surgery group received open partial laryngectomy(57 cases),and the minimally invasive group received carbon dioxide laser laryngectomy(44 cases).Follow-up visits were made by telephone and outpatient visits,and the operation time,postoperative laryngeal mucosa edema time,length of stay,5-year survival rate,complication rate and recurrence rate of the two groups were compared in the different clinical stages(stage Ⅰ,stage Ⅱ,and stage Ⅲ)and tumor locations(glottic type and non-glottic type).Results·The operation time,postoperative laryngeal mucosa edema time and length of stay of the minimally invasive group were shorter than those of the open surgery group(P＜0.05).Comparison of the 5-year survival rates of patients with the same clinical stage and glottic type between the two groups showed no statistically significant difference(both P＞0.05);while comparison of the 5-year survival rates of patients with non-glottic type between the two groups(62.5％in the open surgery group vs 0 in the minimally invasive group)showed a statistically significant difference(P＜0.05).In the minimally invasive group,there were 3 cases of complications,including 1 case of fever and 2 cases of lung infection;in the open surgery group,there were 14 cases of complications,including 5 cases of fever,7 cases of lung infection and 2 cases of pharyngeal fistula.The complication rate of patients in the minimally invasive group(6.82％,3/44)was lower than that in the open surgery group(24.60％,14/57),and the difference was statistically significant(P＜0.05);the complication rate of patients with stage Ⅱ and glottic type in the minimally invasive group was significantly lower than that in the open surgery group(P＜0.05).Comparing the recurrence rate of patients in the two groups(10.53％in the open surgery group vs 2.27％in the minimally invasive group),the difference was not statistically significant(P＞0.05).Conclusion·Compared with open partial laryngectomy,carbon dioxide laser laryngectomy has faster postoperative recovery and lower complication rate in the treatment of early and middle laryngeal malignant tumors,so it is worth promoting.

Objective To explore the correction of beam trajectories in the presence of fringe fields in magnetic resonance imaging-guided proton therapy and dose changes in the body before and after correction.Methods The open-source treatment planning software matRad was used to design plans for brain tumor,liver tumor,and prostate cancer cases,and simulation studies were conducted in the Monte Carlo simulation toolkit TOPAS to calculate proton dose distribution.A proton beam trajectory correction model suitable for three-dimensional magnetic fields was established,and a beam trajectory correction algorithm was developed.The deflection of the proton Bragg peak in the presence of fringe fields was analyzed.Furthermore,3 treatment plans were simulated and dose correction was carried out when the fringe field existed.Gamma analysis method is used to evaluate the correction effect;and the dose changes in the target area and organs-at-risk after correction were quantitatively analyzed.Results The perturbation of the magnetic field would cause lateral deflection of the proton beam trajectory,and the presence of fringe fields would significantly increase this effect,which increased with the increasing of beam energy.When the fringe field existed,the treatment plans for brain tumor,liver tumor,and prostate cancer were corrected.Under the 3%/3 mm criterion,the gamma passing rates for target area were 94.844%,92.054%,and 97.863%,respectively,and after correction,the total dose in the body was increased by 2.8%,2.5%,and 1.5%,respectively.The increased dose was mainly contributed by incident protons.Conclusion In magnetic resonance imaging-guided proton therapy,the effects of fringe fields should be considered.The increase in incident proton beam energy after correction will lead to an increase in the total dose in the body.Since the beam trajectory still has curvature,the dose changes differently in different organs-at-risk.