Value of RBC scan in unexplained GI bleed and role of capsule endoscopy

RBC scan in unexplained GI Bleed locates the site and further localization is done with Capsule endoscopy in small bowel disease. A 61 years old female had synchronous malignancy of Adenocarcinoma of splenic flexure of colon and squamous cell carcinoma of uterine cervix stage II B. Patient had left hemicolectomy and following surgery she was treated with 6 MV x-ray beam to pelvis upto 66 Gy with weekly cisplatin with paraaortic radiation upto 50 Gy followed by intracavitary radiation. The patient was treated with 6 cycles of xelox chemotherapy subsequently. 6 months later patient developed complaints of malena. Management: On evaluation, hemoglobin was 6g/dl and packed red cell transfusions were given. Upper GI endoscopy was within normal limits. Stool for occult blood - positive. Colonoscopy revealed radiation proctitis. Tagged RBC Scan - 2 mg of SnCl₂ is dissolved in 2 ml normal saline and 1ml of SnCl₂ is injected intravenously and 20 minutes later sodium pertechnate 25mCi was given to label RBC. Initially dynamic images of the abdomen and pelvis (anterior and posterior) were acquired @ 1 sec/frame for 1 minute and 1 minute/ frames for 30 minutes. Later static images were acquired at 2, 4, 6 and at 24 hours. It showed increased uptake in right hypochondrium region below the liver and the 24 hours imaging also showed increased uptake in same site. Capsule endoscopy was done and it revealed chronic radiation enteritis in jejunum and ileum. No bleeding sites were noted in large bowel. The patient was conservatively managed. Tagged RBC scan is helpful in locating the unexplained GI bleed and it is a road map for further localization of the site especially in small bowel with capsule endoscopy. This is to highlight the combination is very useful. (author)