Usefulness of diffusion-weighted magnetic resonance imaging for evaluating the effect of hemostatic radiotherapy for unresectable gastric cancer.

There are several reports that vouch for the usefulness of diffusion-weighted image (DWI) in making a diagnosis before treatment. However, no study has evaluated the effect of radiotherapy (RT) for unresectable gastric cancer. In the present case report, we evaluated the effectiveness of RT using DWI. An 81-year-old man was hospitalized with a broken bone and then diagnosed with advanced gastric cancer with breeding. He had chorionic renal failure and surgery was impossible. Further, contrast-enhanced computed tomography and magnetic resonance imaging (MRI) were not performed due to renal failure, whereas palliative RT was performed. We followed up the patient using blood test and MRI (DWI) to estimate whether bleeding had stopped or not after radiotherapy. Hemostasis effect was found after 2 weeks of RT. In DWI examination, there was a decrease in the tumor signal intensity 30 days after RT. Similarly, at day 60, the tumor signal intensity further decreased on DWI and the blood test results indicated no progression of anemia. At 4 months after the RT, the patient died because of respiratory failure without any bleeding. DWI is useful not only for the initial diagnosis but also for evaluating the effectiveness of RT.Trial registration: National clinical study registered number: UMIN000026362.