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Medical physicists play an important role in the delivery of radiotherapy. Compared with China′s mainland, Hong Kong has established a more mature training mode and a more complete management system for medical physics talents. In this article, the authors introduced the current state of medical physics talent training, as well as the recruitment, certification and promotion of medical physicist in Hong Kong by querying the official websites of medical physics organizations, reviewing related literature and interviewing senior medical physicists in Hong Kong. The authors also analyzed the shortcomings in the construction of medical physics talent system in China′s mainland and made valuable suggestions.
ABSTRACT
The training program of radiation therapists in the United States has been established early, and the mode of training, qualification and continuing education are relatively complete. Literature review was conducted at home and abroad and United States Department of Labor, American Registry of Radiologic Technologists, American Society of Radiologic Technologists as well as Joint Review Committee on Education in Radiologic Technology websites were reviewed. The training mode, qualification, work content, continuing education and employment situation of American radiotherapists were analyzed, aiming to provide some reference and enlightenment for the establishment of a new model for the training of professional radiologists suitable for the national conditions of China Mainland.
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Objective@#To evaluate the correlation between computed tomography (CT) features and malignancy risk category of small (≤5 cm) gastric stromal tumors (GST), in order to provide an image reference for preoperative assessment and intraoperative pathological diagnosis.@*Methods@#Eighty-three patients with surgically and pathologically proven GST (≤5 cm) between January 2011 and November 2015 were recruited, and their clinical, pathological and CT data were retrospectively analyzed. According to the pathological results and malignancy risk category, the patients were divided into 2 groups, the benign biological behavior group (very low and low risk) and malignant biological behavior group (intermediate and high risk). The clinical, pathological and CT imaging findings of the two groups were analyzed. Based on the tumor diameter, the receiver operating characteristic curve (ROC) was applied to evaluate the sensitivity, specificity and the best cut-off point for distinguishing the malignancy risk between the two groups.@*Results@#The lobulation and ulceration of the tumors presented statistically significant difference for the malignancy risk between the two groups (χ2=6.273 and 4.163, respectively; all P<0.05), but there was no significant difference in the sex, clinical symptoms, serum ferritin, tumor site, growth pattern, cystis degeneration and calcification (all P>0.05). No statistically significant differences were detected for the tumor CT value, arterial CT value, venous CT value, degrees of enhancement in arterial phase (DEAP), enhancement in portal venous phase (DEPP), and patient′s age for distinguishing the malignancy risk between the two groups (all P>0.05). On the other hand, significant differences were found in the maximum diameter (Dmax) of tumor and the minimum diameter (Dmin) of tumor (t=-3.256 and -3.466, respectively; all P<0.05). When the cut-off point of Dmax was 1.6 cm, the area under the ROC curve, sensitivity and specificity were 0.704, 92.3% and 75.4%, respectively. When the cut-off point of Dmin was 1.5 cm, the area under the ROC curve, sensitivity and specificity were 0.713, 88.5% and 71.9%, respectively.@*Conclusion@#CT features of the GST (≤5 cm) may predict, before surgery, the malignancy risk of small gastric stromal tumors, and provide the an image reference for preoperative assessment and intraoperative pathological diagnosis of the disease.
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Objective@#To explore the application value of CT imaging in differentiating gastric stromal tumors (GST) from gastric leiomyomas (GLMs).@*Methods@#CT images of patients with GST (n=65) or GLMs (n=13, maximum diameter of tumor ≤5 cm) proved by surgery and pathology were retrospectively analyzed. The tumor size, location, contour, growth pattern, degree and pattern of enhancement, calcification, necrosis, surface ulceration, lymph nodes, and patient clinical data were evaluated by two independent reviewers. Receiver operating characteristic (ROC) curves were employed to assess the measurement and calculation parameters in the differentiation of GST and GLMs.@*Results@#Between the GST and GLMs groups, there was no statistically significant difference in the contour, growth pattern, calcification, surface ulceration, and patient's sex (P>0.05). CT values of in plain scans, degree of enhancement in arterial phase (DE1), size, location and pattern of enhancement were found to be different between GST and GLMs (P<0.05). When the cutoff value of the maximum tumor diameter was 3.2 cm, the area under ROC curve, sensitivity and specificity were 0.707, 92.3%(12/13) and 60.6%(40/66), respectively. When the cutoff value of age was 59 years, the area under ROC curve, sensitivity and specificity were 0.773, 92.3% (12/13) and 46.2% (30/65), respectively. Taking the cutoff value of 10.9 HU as the degree of enhancement in arterial phase (DE1), the area under ROC curve, sensitivity and specificity were 0.774, 84.6% (11/13) and 77.3% (51/66), respectively. Using a cutoff value of 30.3 HU, the sensitivity, specificity, and the area under ROC curve were 84.6% (11/13), 65.2% (43/66), and 0.731, respectively.@*Conclusions@#CT examination in addition to clinical data can be very helpful for the differential diagnosis of GLMs from GSTs in maximum diameter ≤5 cm.