title: Radiologic measurements of tumor response to treatment: practical approaches and limitations.
abstract: Objective response assessment is important to describe the treatment effect of anticancer drugs. Standardization by using a "common language" is also important for comparison of results from different trials. In contrast to clinical results, which can be subjective, diagnostic imaging provides a greater opportunity for objectivity and standardization. It was generally accepted that a decrease in tumor size correlated with treatment effect; as a result, imaging was adopted for lesion measurement in the World Health Organization (WHO) criteria in 1979. However, because of some limitations of the WHO criteria, the Response Evaluation Criteria in Solid Tumors (RECIST) were introduced in 2000. In RECIST, imaging was recognized as indispensable for response evaluation of solid tumors. Nevertheless, the widespread use of multidetector computed tomography and other imaging innovations have made RECIST outdated, with a concomitant need for modifications. Meanwhile, newer anticancer agents with targeted mechanisms of action have demonstrated an inherent limitation and unsuitability of anatomic tumor evaluation that assesses only lesion size. In addition, the effect of these new drugs changes the paradigm according to which tumor response or response rate is measured. Complete and partial responses cannot be the end points in all clinical trials; in some cases, disease control or progression-free survival may be the more relevant end point.
authors: Department of Diagnostic Radiology, Institution for Molecular Medicine and Surgery, Karolinska University Hospital Solna and Karolinska Institute, Stockholm S-171 76, Sweden. Chikako.Tanaka@ki.se
authors: Chikako
authors: C
authors: Suzuki
authors: Hans
authors: H
authors: Jacobsson
authors: Thomas
authors: T
authors: Hatschek
authors: Michael R
authors: MR
authors: Torkzad
authors: Katarina
authors: K
authors: Bodén
authors: Yvonne
authors: Y
authors: Eriksson-Alm
authors: Elisabeth
authors: E
authors: Berg
authors: Hirofumi
authors: H
authors: Fujii
authors: Atsushi
authors: A
authors: Kubo
authors: Lennart
authors: L
authors: Blomqvist
mesh_terms: D002986:Clinical Trials as Topic; D003952:Diagnostic Imaging; D018450:Disease Progression; D006801:Humans; D009369:Neoplasms / Q000473:pathology* / Q000628:therapy*; D017410:Practice Guidelines as Topic; D015203:Reproducibility of Results; D012107:Research Design; D017211:Treatment Failure; D016896:Treatment Outcome; D014944:World Health Organization