Imaging techniques in tumour staging, treatment planning, follow-up and patient outcome evaluation

Tumour imaging is widely used during the whole process of cancer management from detection of initial tumour to evaluation of cure or relapse. The main problems with tumour imaging are: spatial and contrast resolution, image noise, artifacts and distortion. At the same time, each imaging technique used in a given epidemiological context has a sensitivity, specificity, diagnostic accuracy and predictive value which must be evaluated properly to enable an adequate decision to be made with regard to the most appropriate method. An evaluation of the predictive value of clinical evaluation and CT or NM scan in detecting metastases in the brain, liver and bone of various primary tumours (breast, lung, colorectal) demonstrates the high value of clinical investigation which is approaching that of CT and NM scanner in the case of brain metastases in particular. Two WHO Technical Reports (TRS 689 and 723) have attempted to rationalize the use of major imaging technologies (radiographic, CT and ultrasound). The principal aspects of tumour imaging covered in these reports are briefly outlined. Regarding the effect of tumour imaging on health outcome, Norlund and collab. have demonstrated that CT staging can improve the patient survival curve in comparison with other staging techniques. Such types of studies are necessary in order to improve the efficiency of tumour imaging in daily practice. (Author)