Radioisotopic Scanning in Liver Echinococcosis

Abstract

The authors have had the opportunity of studying 65 patients with liver echinococcosis over a three-year period. This report is a summary analysis of the clinical, roentgen, laboratory, and radioisotopic examinations carried out in these patients. The hydatid scolices grow six weeks in the dog intestine. The developing tapeworm lives six to twelve months, producing a proglottis with 500 to 800 ova. Each, if ingested by man, changes into a larva which penetrates the portal tributary veins, usually enters the liver, and changes into a sack with germinative, chitinous, and fibrocalcified layers (1, 2). Superficial cysts become symptomatic earlier than those deeply situated. The latter may be missed even by the surgeon. In addition, the symptomatology is often misleading and the diagnosis difficult in the presence of complications like infection, rupture, or penetration of the cyst to the biliary tract. The existing roentgen and laboratory tests are not pathognomonic, and hence the addition of a radioisotopic study seems worthwhile (3, 4). This last is based on an automatic scanning of the area after injection of colloidal suspension of radioactive gold (Au¹⁹⁸) or radioactive rose bengal labeled by I¹³¹ (RRB) (5), both hepatotropic radioisotopes. Material and Methods The series was comprised of 37 females and 28 males, with an age range from eleven years to eighty-one and a mean age of fifty-one. Eighty per cent of the patients originated in countries with endemic hydatidosis (Iraq, Turkey, etc.); 12 per cent (8 patients) were Israeli-born. In every instance clinical and laboratory examinations were performed in the attending department, and in 63 cases roentgenstudies were carried out. Matters of particular interest included the position and mobility of the right diaphragm, calcifications in the hepatic region, and the pressure effects on the surrounding organs by an enlarged or deformed liver. Surgery was performed in 34 of the 40 patients whose livers were scanned before operation for hydatid cyst. In the other 25, surgery preceded scanning. Re-operation was carried out in 14 cases. Before performance of the radioisotopic examination, the xiphoid process, costal margin, and the lower limits of the liver were marked on the skin. The radioisotope was then injected in amounts varying with the body weight (3–5 μc per kilogram, with a mean dose of Au¹⁹⁸ equalling 285 μc or of RRB equalling 330 μc). Ten to fifteen minutes later the scanning was instituted (6). For the scanning an autoscanner (Nuclear Chicago) and a Picker cliniscanner were employed. The detectors were provided with thallium-activated sodium iodide cystals of 2-in. diameter and a 19-hole focusing collimator. A discriminator was incorporated in the cliniscanner.