2020 Volume 58 Issue 2 Pages 112-121
In order to evaluate the effectiveness of abdominal ultrasound cancer screening using the "Manual for Abdominal Ultrasound in Cancer Screening and Health Checkups," we examined the detection rate of malignant tumors in category (C) -3, C-4, and C-5 in 17,274 people who underwent abdominal ultrasonography screening from January 2015 to December 2016. Malignant tumors were found in two of 389 pancreatic C-3 patients; therefore, the malignant tumor detection rate was 0.5%. Malignant liver tumors from C-4 were found in 5 out of 50 cases (malignant tumor detection rate: 10%); biliary tract, 2 out of 18 cases (malignant tumor detection rate: 11.1%); pancreas, 3 out of 14 cases (malignant tumor detection rate: 21.4%); and kidney, 4 out of 12 cases (malignant tumor detection rate: 33.3%). Whole malignant tumors from C-4 were found in 14 of 94 cases (malignant tumor detection rate: 14.9%). Malignant tumors from C-5 were found in 6 out of 6 cases (pancreas, 3 out of 3 cases; kidney, 3 out of 3 cases (malignant tumor detection rate: 100%) ). Further, in order to evaluate the degree of malignancy of each "ultrasound image finding" of C-4, we classified C-4 into C-4a (low suspicion of malignancy) and C-4b (moderate suspicion of malignancy). Ultrasound image findings of "solid lesions, with a maximum diameter of 15 mm or more," in the liver were significantly less likely to be malignant than other ultrasonic image findings in C-4.
In the pancreas, it was suggested that ultrasound image findings of "main pancreatic duct dilatation, nodule in the main pancreatic duct" are more likely to be malignant than other ultrasound image findings in C-4. Similarly, in the kidney, ultrasound image findings of "solid lesions, accompanied by either an internal non-echo area, a marginal low echo band, or lateral shadow," are more likely to be malignant.
We should consider the differences in the possibility of malignant findings for each ultrasound finding in Category 4
