Objective:To compare the uncertainty of dose calibration systems between EBT4 and EBT3 films, and to evaluate the effectiveness and accuracy of EBT4 films in radiotherapy dose measurements.Methods:EBT4 and EBT3 films were irradiated with clinical 6 MV photon beams at doses ranging from 0 to 1,600 MU. Films were scanned after resting for 0 and 24 h to establish dose calibration functions based on net optical density. The dose uncertainties introduced by function fitting, dose resolution, film non-uniformity, scan repeatability, and scanner non-uniformity during calibration of the two films were obtained through experimental tests and mathematical calculations. Independent-sample t-tests were used to compare differences in fitting uncertainty and dose resolution between the two films, while homogeneity of variance tests were used to compare differences in film non-uniformity and scan repeatability. The combined total uncertainty was then calculated and compared. Finally, the total combined uncertainty was calculated by integrating all individual sources of uncertainty and compared between the two films. Results:Within the absorbed dose range of 1-12 Gy, EBT4 films exhibited significantly lower dose uncertainties from function fitting and dose resolution than EBT3 films at the same standing time ( P<0.01). No significant differences were observed between the two films in terms of non-uniformity and scan repeatability ( P>0.05). The total dose uncertainties of EBT4 and EBT3 films at 0 h standing were 5.65% and 7.87%, respectively, while the total uncertainties at 24 h standing were 4.73% and 6.33%, respectively. Overall, the dose calibration system of EBT4 films demonstrated consistently lower total uncertainty. Conclusion:Under identical conditions, EBT4 films demonstrate superior and more stable dose uncertainty compared with EBT3 films, thereby meeting the clinical requirements for radiation dose measurements with higher precision.

Objective:To compare the uncertainty of dose calibration systems between EBT4 and EBT3 films, and to evaluate the effectiveness and accuracy of EBT4 films in radiotherapy dose measurements.Methods:EBT4 and EBT3 films were irradiated with clinical 6 MV photon beams at doses ranging from 0 to 1,600 MU. Films were scanned after resting for 0 and 24 h to establish dose calibration functions based on net optical density. The dose uncertainties introduced by function fitting, dose resolution, film non-uniformity, scan repeatability, and scanner non-uniformity during calibration of the two films were obtained through experimental tests and mathematical calculations. Independent-sample t-tests were used to compare differences in fitting uncertainty and dose resolution between the two films, while homogeneity of variance tests were used to compare differences in film non-uniformity and scan repeatability. The combined total uncertainty was then calculated and compared. Finally, the total combined uncertainty was calculated by integrating all individual sources of uncertainty and compared between the two films. Results:Within the absorbed dose range of 1-12 Gy, EBT4 films exhibited significantly lower dose uncertainties from function fitting and dose resolution than EBT3 films at the same standing time ( P<0.01). No significant differences were observed between the two films in terms of non-uniformity and scan repeatability ( P>0.05). The total dose uncertainties of EBT4 and EBT3 films at 0 h standing were 5.65% and 7.87%, respectively, while the total uncertainties at 24 h standing were 4.73% and 6.33%, respectively. Overall, the dose calibration system of EBT4 films demonstrated consistently lower total uncertainty. Conclusion:Under identical conditions, EBT4 films demonstrate superior and more stable dose uncertainty compared with EBT3 films, thereby meeting the clinical requirements for radiation dose measurements with higher precision.

Objective To investigate the imaging features of invasive micropapillary carcinoma(IMPC)of the breast in magnetic resonance imaging(MRI)and mammography(MG).Methods The clinical data of 25 patients with IMPC confirmed by biopsy or surgical pathology were retrospectively collected from Cancer Hospital of Shantou University Medical College from January 2017 to April 2023.All patients underwent MRI examination,20 of which underwent MG examination.Imaging features,histopathological features and receptor status of patients were recorded and analyzed.Results In 25 patients,20 patients had palpable mass.A total of 33 lesions were detected by MRI.One patient had a non-mass lesion and 24 had a lump-like lesion.The lump was mainly irregular in shape,with irregular or burr edges,and the apparent diffusion coefficient was(0.862×10-3±0.135×10-3)mm2/s.The time-signal intensity curve of the lump was mainly flat or outflow type.MG showed no abnormality in one patient,22 lesions were detected in 19 patients,and the lump were mostly irregular in shape,with unclear edges or burrs,and 10 patients showed the lump accompanied by microcalcification.Lymph node abnormalities were detected in 11 cases by MRI and 6 cases by MG,respectively,and axillary lymph node metastasis was found in 14 cases by final pathology.Immunohistochemical results showed that 24 cases were positive for estrogen receptor,22 cases were positive for progesterone receptor and 7 cases were positive for human epidermal growth factor receptor 2.Conclusion The imaging findings of IMPC mostly showed irregular shape,unclear boundary,multiple burrs at the edge,uneven enhancement,soft tissue mass with microcalcification,and high axillary lymph node metastasis rate,which could provide important references for the clinical treatment and prognosis evaluation of IMPC.

Objective To evaluate the related factors in 3.0T MR imaging features for predicting triple negative breast cancer (TNBC).Methods Totally 191 patients with breast cancer confirmed by histopathology were enrolled,among them 25 were TNBC (TNBC group),while the other 166 were non-TNBC (non-TNBC group).All patients underwent 3.0T MR examination.Patient age,tumor size,shape,margin,enhancement pattern,signal intensity on T2WI,time-intensity curve (TIC),ADC value,and peritumoral vessel between the two groups were compared.Univariate and multivariate Logistic regression analyses were used to predict the related factors.Results Compared with non-TNBC group,smooth margin (P=0.023),round mass (P=0.001),rim enhancement (P＜0.001),high signal intensity on T2WI (P=0.003),higher ADC value (P=0.022) and increased peritumoral vessel (P=0.046) were significantly associated with TNBC.Further multivariate Logistic regression analysis identified four independent risk factors of TNBC (all P＜0.05),including enhancement pattern,signal intensity on T2WI,ADC value and increased peritumoral vessel.The area under ROC curve of combination of the 4 factors was 0.840.Conclusion Rim enhancement of mass,high signal intensity on T2WI,higher ADC value,and increased peritumoral vessels are independent risk factors in predicting TNBC.