The usefulness of film reading to detect cancer by untrained radiographer in X-ray examination of the stomach

Until now, the evaluations of the film reading performance of radiographers have been studied to assist diagnosis and to alleviate the shortage of radiologists. However, little has been reported on evaluating the film reading by radiographers in X-ray examination of the stomach. To investigate whether present radiographer can assist diagnosis in X-ray examination of the stomach or not, the film reading performance of untrained radiographer to detect cancer was evaluated. The institutional review board approved this retrospective study and informed consent was not required. A test set films of 100 cases (50 negative and 50 positive; mean age, 55 years; range, 33-78) in X-ray examination of the stomach were selected from 192,404 people in gastric cancer screening that was performed in Osaka, Japan between 2000 and 2002. The positive cases were defined as cancer cases, which were selected by 10 on the grade of five scales for difficulty. The negative cases were selected at random from without cancers that were confirmed by screening result at least two years later. Eleven radiographers and one radiologist scored the test set on a 5-point scale. A receiver operating characteristic (ROC) analysis was performed and area under the ROC curve (AUC) was defined as the film reading performance of radiographer or radiologist to detect cancer. The ROC analysis was performed according to the method of DeLong et al. A p value of less than 0.05 was required for significance. As a result, 5 of the 11 radiographers' AUC (0.85-0.79) were slightly lower than the radiologist's AUC (0.86) (p > 0.05). However, the other 6 radiographers' AUC (0.74-0.62) were lower than the radiologist's AUC (0.86) (p < 0.05). The highest AUC of radiographer (AUC, 0.85; sensitivity, 78%; specificity, 84%) and the AUC of radiologist (AUC, 0.86; sensitivity, 86%; specificity, 76%) were almost equal (p = 0.673). These results show a possibility that untrained radiographers with higher film reading performance to detect cancer can assist diagnosis in X-ray examination of the stomach, because some higher film reading performance of several untrained radiographers was comparable to that of a radiologist.