SURGICAL RELEVANCE OF DIAGNOSTIC-IMAGING TECHNIQUES IN PRETHERAPEUTICSTAGING OF CARCINOMA OF THE ESOPHAGUS, STOMACH, COLON AND RECTUM

The increasing spectrum of therapeutic options for tumors of the gastr ointestinal tract has resulted in a refinement of the pretherapeutic d iagnostic strategies. The diagnostic approach in surgical institutions that are focused on primary surgical resection will therefore be much less sophisticated than in institutions who propose a selective thera peutic approach based on the pretherapeutic tumor stage and prognostic parameters. Pretherapeutic assessment of the depth of tumor infiltrat ion, i.e. the T-category, is essential because most further diagnostic and therapeutic decisions are based on this information. This can tod ay be achieved with a high degree of accuracy by endoscopy and endosco pic ultrasonography. Early T-stages (T1-2) are usually an indication f or primary surgical resection and, after exclusion of distant metastas es, no further diagnostic studies are required. In patients with local ly advanced esophageal, gastric or rectum tumors (T3-4) multimodal the rapeutic concepts should be considered. This usually requires addition al diagnostic studies. None of the available diagnostic imaging modali ties today allows satisfactory pretherapeutic assessment of lymph node metastases. The assumed nodular status should therefore currently not influence therapeutic decisions. Essential is, however, the assessmen t of distant metastases, since the documentation of distant tumor spre ad will change the therapeutic approach to a palliative situation. Det ailed histologic and molecular-biologic assessment of tumor characteri stics is growing in importance. This not only provides therapeutically relevant information regarding tumor grading, but opens the door towa rds a modern molecular diagnostic approach. It can be expected that in the near future a vast amount of relevant prognostic information can be obtained from endoscopic tumor biopsies, which may soon alter our t herapeutic concepts.