Fast prediction of personalized abdominal organ doses from CT examinations by radiomics feature-based machine learning models.

The X-rays emitted during CT scans can increase solid cancer risks by damaging DNA, with the risk tied to patient-specific organ doses. This study aims to establish a new method to predict patient specific abdominal organ doses from CT examinations using minimized computational resources at a fast speed. The CT data of 247 abdominal patients were selected and exported to the auto-segmentation software named DeepViewer to generate abdominal regions of interest (ROIs). Radiomics feature were extracted based on the selected CT data and ROIs. Reference organ doses were obtained by GPU-based Monte Carlo simulations. The support vector regression (SVR) model was trained based on the radiomics features and reference organ doses to predict abdominal organ doses from CT examinations. The prediction performance of the SVR model was tested and verified by changing the abdominal patients of the train and test sets randomly. For the abdominal organs, the maximal difference between the reference and the predicted dose was less than 1 mGy. For the body and bowel, the organ doses were predicted with a percentage error of less than 5.2%, and the coefficient of determination (R2) reached up to 0.9. For the left kidney, right kidney, liver, and spinal cord, the mean absolute percentage error ranged from 5.1 to 8.9%, and the R2 values were more than 0.74. The SVR model could be trained to achieve accurate prediction of personalized abdominal organ doses in less than one second using a single CPU core.

Preoperative Differential Diagnosis of Benign and Malignant Retroperitoneal Tumors Clinicoradiologic Analysis

PURPOSE: Retroperitoneal soft tissue sarcomas are frequently found in advanced state due to the abscent or nonspecific symptoms, and the only hope for cure is a radical resection. The differentiation between benign and malignant tumor is a prerequisite for preoperative preparation and deciding the extent of resection. for the purpose of determining the malignancy of retroperitoneal tumor, we evaluate the clinic oradiologic features of the patients. METHODS: Retrospective study was done on 37 eases who were oper ated Korea University Hospital from Jan. 1990 to Dec. 1998. Their clinicoradiologic characters were analyzed and compared between benign and malignant tumor pationts. RESULTS: Among the 37 cases, 27 cases (73%) were benign tumors and the remaining 10 cases (27%) were malignant tumors. There was no significant difference in age distribution between malignant and benigntumor group (p>0.05) Among 20 male patients, 10 eases had malignant tumor (50%) but all 17 female patients had benign tumor (p=0.001) Preoperative symptoms were present in 29 cases (78.4%). and mean duration of symp toms in malignant cases was 20 months and in benign cases was 18 months but had no significance in differentiating between malignant and benign tumors (p>0.05) All eases were porformed abdominal CT scanning and it had 100% of sensitivity and 74% of specificity. Among the radiologic characteristics, size of tumor, irregular margin, and abscence of calcification were correlated with malignancy (p<0.05). CONCLUSION: Preoperative clinical symptoms and duration are not helpful in differentiating the malig naney but CT scanning has a good results for such purpose. So when the retroperitoneal tumor shows large size, irregular margin and no visible calcification especially in male patients, the patient, we should prepare and treat the patients according to malignant tumor.

Preoperative Differential Diagnosis of Benign and Malignant Retroperitoneal Tumors Clinicoradiologic Analysis

PURPOSE: Retroperitoneal soft tissue sarcomas are frequently found in advanced state due to the abscent or nonspecific symptoms, and the only hope for cure is a radical resection. The differentiation between benign and malignant tumor is a prerequisite for preoperative preparation and deciding the extent of resection. for the purpose of determining the malignancy of retroperitoneal tumor, we evaluate the clinic oradiologic features of the patients. METHODS: Retrospective study was done on 37 eases who were oper ated Korea University Hospital from Jan. 1990 to Dec. 1998. Their clinicoradiologic characters were analyzed and compared between benign and malignant tumor pationts. RESULTS: Among the 37 cases, 27 cases (73%) were benign tumors and the remaining 10 cases (27%) were malignant tumors. There was no significant difference in age distribution between malignant and benigntumor group (p>0.05) Among 20 male patients, 10 eases had malignant tumor (50%) but all 17 female patients had benign tumor (p=0.001) Preoperative symptoms were present in 29 cases (78.4%). and mean duration of symp toms in malignant cases was 20 months and in benign cases was 18 months but had no significance in differentiating between malignant and benign tumors (p>0.05) All eases were porformed abdominal CT scanning and it had 100% of sensitivity and 74% of specificity. Among the radiologic characteristics, size of tumor, irregular margin, and abscence of calcification were correlated with malignancy (p<0.05). CONCLUSION: Preoperative clinical symptoms and duration are not helpful in differentiating the malig naney but CT scanning has a good results for such purpose. So when the retroperitoneal tumor shows large size, irregular margin and no visible calcification especially in male patients, the patient, we should prepare and treat the patients according to malignant tumor.