10194- MET-15 USEFULNESS OF DWIBS IN SYSTEMIC EXAMINATION FOR METASTATIC BRAIN TUMOR

Abstract INTRODUCTION DWIBS is an abbreviation for Diffusion Weighted Whole Imaging with Background body signal Suppression. It is an imaging method that uses MRI diffusion-weighted imaging (DWI) to image the entire body in multiple locations and then integrates them to form a wide-area image. In recent years, MRI has been used to search for heat sources of unidentified fever and distant metastasis of cancer. In this report, we describe two cases in which DWIBS was useful in the search for the primary tumor in patients with brain metastases. CASE PRESENTATION Case 1: Male in his 60s. The patient presented with headache and diplopia, and MRI showed a neoplastic lesion in the clivus bone. A transnasal endoscopic surgery was performed, and he was diagnosed with bone metastasis of squamous cell carcinoma. Contrast-enhanced whole body CT showed similar findings, and the patient was found to have brain metastasis of esophageal cancer. Case 2: Male, 50s. He presented with a complaint of left facial paralysis and left incomplete paralysis, and a head MRI showed a brain tumor in the right middle frontal gyrus. A craniotomy was performed, and the pathological diagnosis was adenocarcinoma. A systemic search did not reveal a primary tumor, and the patient was diagnosed with cancer of unknown primary, but later lung lesions became apparent. The DWIBS performed at that time also showed a high signal at the site where lung cancer was diagnosed. DISCUSSION In Japan, MRI is widely used, and DWIBS is gradually becoming popular as a whole-body search method because it can be performed with current MRI equipment. DWIBS may be an option for primary tumor detection in facilities or regions where 18F-FDG PET is not readily available. CONCLUSION DWIBS may be useful for close examination of primary metastatic brain tumors, and more cases should be accumulated in the future.