ABSTRACT
Objective:To test the relative response of a detector matrix used for measuring of the dose distribution in radiotherapy in order to ensure the accuracy and reliability of dose distribution measurement result.Methods:The two adjacent detectors can be irradiated at the same radiation dose by translating the detector matrix. The relative response of each detector to the reference detector can be obtained by combining the recursive algorithm. At the same time, the measurement data at different test steps are corrected to the reference step by setting the reference step, which correct the influence on the relative response result caused by the variation of the radiation condition and the detector response.Results:Based on the actual test of a 32 × 32 detector matrix, the relative response of each detector of the detected detector matrix to the reference detector varied from 0.896 to 1.077, with the expanded uncertainty of the relative response result being 0.8% ( k=2). Conclusions:On the premise of no known distribution of a radiation field, the relative response relationship of each detector of a detector matrix can be obtained by this method accurately and expediently, which provides a basic method for the performance evaluation of the detector matrix. The same idea can also be used to determine the relative response relationship of other detector matrices for different measurement purposes.
ABSTRACT
ObjectiveTo investigate the characteristics,treatment and prognosis of solid pseudopapillary tumor of the pancreas(SPTP)in the minor. MethodsCombining minor SPTP cases in literatures and 4 cases, analyzed the clinical and pathological features, and the relationship with sex hormone receptors, the growth and development,treatment and prognosis.ResultsThe clinical manifestations of SPTP in minor were same as adults, but the minors showed significant growth retardation which can be reversed after the tumor surgical removal, like 4 patients all showed secondary sex characteristics of retardation in the group. The protocol of surgical treatment was to ensure complete removal of the tumor and keep the healthy organs as much as possible which reduced the impact to the postoperative growth and development.The premise of operation therapy in the 4 cases was minimization of operation trauma. Minor SPTP prognosis had not been determined. ConclusionThe diagnosis and treatment of minor SPTP should be fully taken into account the characteristics of the minor to ensure that patients can continue long-term growth and development and the quality of life.
ABSTRACT
Objective To assecess the role of CT in the diagnosis and the reasons of misdiagnosis of biliary duct carcinoma.Methods 23 cases with biliary duct carcinoma pathologically comfirmed were reviewed.Results 2 cases were peripheral type,10 cases were major intrahepatic biliary duct type,7 cases were extrahepatic type and 4 cases ampullar type.The masses within biliary duct were showed by CT in 16 cases.The obstruction of biliary duct was cut off abruptly in 18 cases and narrowing sharply in 5 cases.The intrahepatic biliary duct indicated mild or marked expansion,of them,17 cases were showed as vine and 6 as segmental.The extrahepatic biliary duct were dilated in 11 and gallbladder dilatation in 7.4 cases were misdiagnosed and leaked diagnosis was in one cases by CT preoperation.Conclusion CT is valuable in diagnosis of biliary duct carcinoma,but it still has some limitations.