title: [Conventional roentgenologic methods and computerized tomography in the preirradiation planning for patients with esophageal cancer].
abstract: During the planning of irradiation of patients with esophageal cancer significant divergence is frequently noted between topometric maps obtained by conventional x-ray methods including axial tomography, and computerized tomography. Topometric maps based on these two methods were compared. Using a typical example of a series of 12 patients, divergences in expected dose loads on critical points were analysed on the basis of 3 variants of superposed topometric maps. Divergences in topometric maps result from errors in topometric methods and from an impossibility to reproduce precisely the level of a section and physiological conditions during repeated layings of a patient. Divergences in a focal dose (on the esophagus) can reach 8% in rotation radiotherapy, 20% in static irradiation, and on the vertebral canal 28 and 13% respectively. Factors that influence such divergences are discussed.
mesh_terms: D003037:Cobalt Radioisotopes / Q000627:therapeutic use; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D005720:Gamma Rays; D006801:Humans; D010347:Patient Care Planning / Q000379:methods*; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed
chemical_list: D003037:Cobalt Radioisotopes
vernacular_title: Konventsional'nye rentgenologicheskie metody i komp'iuternaia tomografiia v predluchevoĭ podgotovke bol'nykh rakom pishchevoda.