ABSTRACT
Objective:To investigate the difference of dose distribution between intensity-modulated photon radiotherapy (IMRT) and intensity-modulated proton radiotherapy (IMPT) in patients with non-small cell lung cancer.Methods:The clinical data of 8 patients with stage Ⅱ-Ⅲ non-small cell lung cancer who received radiotherapy in Ion Medical center of the First Affiliated Hospital of University of Science and Technology of China from November 2020 to April 2022 were retrospectively analyzed. IMRT and IMPT radiotherapy plans were created for each patient separately, the main evaluation indicators were targeted area dose distribution parameters [homogeneity index (HI), conformity index (CI) and the percent volume of volume wrapped by 95% and 100% of prescription dose profile in the targeted area (V 95% and V 100%)], and the average dose (D mean) to the organ at risk and the percent volume of a certain relative biological effect (RBE) dose exposure [D mean, V 5 Gy(RBE) and V 20 Gy(RBE) of ipsilateral lung, D mean, V 5 Gy(RBE) and V 20 Gy(RBE) of bilateral lung, D mean, V 30 Gy(RBE) and V 40 Gy(RBE) of heart, maximum dose (D max) of spinal cord, and D mean of esophageal]. Results:In comparison with IMRT, IMPT reduced the levels of dose parameters in bilateral lung, ipsilateral lung, spinal cord, esophagus, and heart with statistically significant differences (all P < 0.05), especially in D mean of bilateral lung [(4.1±1.8) Gy (RBE) vs. (6.9±1.9) Gy (RBE)], V 5 Gy(RBE) [(15.9±7.1) % vs. (28.5±8.6)%], V 20 Gy(RBE) [(7.4±3.5)% vs. (10.1±3.5)%], and D mean of ipsilateral lung [(9.1±4.5) Gy (RBE) vs. (11.9±3.3) Gy (RBE)], all decreased significantly (all P < 0.001), but the differences in the levels of targeted area dose distribution parameters between them were not statistically significant (all P > 0.05). Conclusions:For patients with non-small cell lung cancer, IMPT is superior to IMRT in the protection of bilateral lung, ipsilateral lung, spinal cord, esophagus and heart.
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Objective:To investigate whether the real-world marital status is a factor affecting the survival of patients with early stage breast cancer.Methods:According to the data of 62 845 patients with early stage (T 1-2N 0M 0) breast cancer who received treatment from January 2012 to December 2015 in the Surveillance, Epidemiology and End Results (SEER) database, univariate survival analysis for 7 factors including age, race, surgery, T stage, tumor differentiation, molecular type and marital status was performed by Kaplan-Meier method. The 5-year cancer specific survival (5-CSS) rate was calculated. Multivariate Cox proportional hazards model was used to analyze the death risk of patients with different marital status (married, unmarried and bad marriage). Results:Univariate analysis showed that 7 factors were correlated with the survival of patients with early stage breast cancer (all P < 0.001). Multivariate analysis showed that marital status was an independent factor affecting the survival of patients, and the death risk of unmarried patients and patients with bad marriage was 2.014 times (95% CI 1.714-2.367, P < 0.001) and 2.559 times (95% CI 2.254-2.905, P < 0.001) higher than that of married patients, respectively. In tumor differentiation, molecular type, T stage and race subgroups, univariate analysis showed that the rates of 5-CSS in married patients were higher than those in unmarried patients and patients with bad marriage (all P < 0.001); multivariate analysis showed that the risk of death in patients with bad marriage (except undifferentiated type) was higher than that in married patients (all P < 0.001), and the risk of death in unmarried patients (except undifferentiation, Luminal B type, black and other races) was also higher than that in married patients (all P < 0.01). Conclusions:Marital status is one of the factors influencing the survival of patients with early stage breast cancer.
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Objective:To compare the dosimetric difference between intensity-modulated photon radiaotherapy (IMRT) planning and intensity-modulated proton radiotherapy (IMPT) planning for glioma.Methods:The clinical data of 15 glioma patients who underwent IMRT in ion medical center of the First Affiliated Hospital of USTC from November 2020 to April 2022 were retrospectively analyzed. IMRT planning and IMPT planning were designed for the image of each patient in the therapy planning system. Main dosimetric parameters were compared including plan target volume (PTV), coverage index (CI), dose homogeneity index (HI), and maximal dose (D max) and mean dose (D mean) of organs at risk between both plans. Results:There were no significant differences between IMRT planning and IMPT planning in terms of D max and D mean of PTV1 and PTV2, CI and HI (all P > 0.05). Compared with IMRT planning, brainstem D mean [6.92 GyE (0.09 GyE, 12.58 GyE) vs. 24.41 GyE (2.59 GyE, 34.18 GyE)], left optic nerve D max [0.78 GyE (0.04 GyE, 25.18 GyE) vs. 20.42 GyE (6.38 GyE, 37.17 GyE)], left optic nerve D mean [0.10 GyE (0.01 GyE, 11.63 GyE) vs. 9.74 GyE (2.99 GyE, 20.87 GyE)], right optic nerve D mean [1.57 GyE (0.13 GyE, 14.90 GyE) vs. 14.08 GyE (2.66 GyE, 23.67 GyE)], left len D max [0 GyE (0 GyE, 2.91 GyE) vs. 4.84 GyE (1.42 GyE, 5.48 GyE)], left len D mean [0 GyE (0 GyE, 1.73 GyE) vs. 3.84 GyE (1.25 GyE, 4.30 GyE)], right len D max [0.25 GyE (0.04 GyE, 4.55 GyE) vs. 4.28 GyE (1.58 GyE, 5.84 GyE)], right len D mean [0.16 GyE (0.01 GyE, 1.95 GyE) vs. 3.73 GyE (1.04 GyE, 4.86 GyE)], pituitary D max [6.97 GyE (0.18 GyE, 39.70 GyE) vs. 36.60 GyE (2.74 GyE, 45.19 GyE)], pituitary D mean [1.36 GyE (0.06 GyE, 13.85 GyE) vs. 24.74 GyE (2.42 GyE, 32.80 GyE)], hippocampus D max [5.10 GyE (0.24 GyE, 26.52 GyE) vs. 35.83 GyE (5.03 GyE, 46.11 GyE)], hippocampus D mean [0.36 GyE (0.04 GyE, 25.65 GyE) vs. 18.79 GyE (2.37 GyE, 28.10 GyE)] in IMPT planning were lower, and the differences were statistically significant (all P < 0.05). There were no statistical differences in brainstem D max [51.98 GyE (0.66 GyE, 53.43 GyE) vs. 53.29 GyE (3.87 GyE, 53.48 GyE)], right optic nerve D max [9.60 GyE (0.01 GyE, 43.32 GyE) vs. 25.37 GyE (3.45 GyE, 41.25 GyE)] of both plans (all P > 0.05). Conclusion:In the radiotherapy for glioma, IMRT and IMPT can meet the dose demand in clinic. Furthermore, IMPT planning can protect organs at risk and reduce radiation dose in hippocampus, brainstem, optic nerve, lens and pituitary.
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Objective To analyze the feasibility and practicality of the navigational template for antegrade lag screw fixation of the fractures in the posterior column of acetabulum.Methods Spiral CT scan data of 40 normal adult pelvis was collected.3D CT scans of pelvics were performed.Virtual 3D pelvic models were reconstructed with software Mimics 10.01.Virtual cylindrical implants were placed along the longitudinal axis of the acetabular posterior column via the ischial tuberosity among the ipsilateral hemipelvis and some anatomical parameters were measured.To adjust cylinder position to determine the best projection point,the shortest distance of the point to the linea terminalis and the anterior border of the auricular surface,the angle between the cylindrical and the coronal plane (α),and the angle between the quadrilateral district and iliac fossa plane (β) were measured respectively.The 3D models were imported into software UG 6.0.The models of navigational templates were designed according to the anatomic features of the acetabulums and the measured parameters.16 cases of dry left side of pelvis specimens were collected.Simulate acetabular posterior column screw fixation from different screw holes and verify the accuracy of navigation template assisted in the nail.Results The navigational templates was designed and manufactured successfully which was more consistent with the anatomical features of the quadrilateral plane.Placement of lag screw from the first hole:6.3％ achieved accurate positioning,75％ well positioning,and 18.7％ loose.From the second hole:81.3％ had accurate positioning,18.7％ well positioning.From the third hole:37.5％ had accurate positioning,62.5％ loose.Conclusion The navigational template designed according to the anatomic features of acetabulum and the measured parameters can accurately assist lag screw placement.