[Scintigraphic localization of the liver and kidneys for abdominal radiotherapy: methods, accuracy and comparison with the ultrasonic procedure].

The exposure of liver and kidney has to be avoided when irradiation fields for radiotherapy of the abdomen are planned and adjusted, unless these organs themselves are the target of therapeutic procedure. A scintigraphic method is presented which allows to transfer the site and borderlines of the organs to the body surface taking exactly into account the irradiation position. A precise transfer of site, size, and shape of the organs facilitates the adjustment of irradiation fields or the positioning of satellite field stops. Scintigraphic organ localization is performed by means of static liver or kidney scintigraphy with suitable radiocolloids for the liver and 99mTc DMSA for the kidneys. The scintigraphic procedure meets all practical requirements regarding the precision of organ localization and shows evident advantages compared to X-ray and ultrasonographic methods. It can be performed at every department of nuclear medicine without preparing the patient and is not influenced by intestinal air artefacts, skeletal parts, obesity, or dystopic organ sites. The results of scintigraphic and ultrasonographic kidney localisation are compared in 15 patients. The scintigraphic procedure has shown to be superior, even with regard to precision and possibility of variable projections to the body surface.