CT and MRI for staging of locally advanced non-small cell lung cancer

Emerging techniques: Whole-body screening and staging with MRI

Strategies for screening or tumor staging include various modalities such as plain radiography, computed tomography (CT), MRI, and ultrasound. Technical innovations have created the feasibility to use MRI to image the entire body in a relatively short time-period. Whole-body MRI may play a potentially important role in evaluating for cancer or vascular disease. This article describes the rationale for using MRI to display the entire body, the techniques employed in whole-body MRI, possibilities and limitations, and summarizes first clinical results for screening and staging purposes.

Role of computed tomography in lung cancer staging

PURPOSE OF REVIEW

Computed tomography has always been an important imaging technique in lung cancer staging but, due to its well-known limitations, additional imaging and/or invasive tests are usually performed. Purpose of this review is to determine whether new developments in CT and in the other staging techniques have changed the role of CT.

RECENT FINDINGS

Despite important technical improvements and the availability of new CT applications, the recent literature confirms the limitations of CT in staging patients with NSCLC. Most attention was given however to other invasive and noninvasive staging techniques and their accuracy in comparison with CT. It was shown that FDG-PET is very useful in the preoperative patient with NSCLC and that it is, especially in N-staging, more accurate than CT. Also combining CT or FDG-PET with EUS-FNA biopsy seems to be a good approach in some indications. Finally, the first reports on the use of integrated PET-CT scanners in lung cancer staging were published and very promising results were shown.

SUMMARY

Computed tomography stays nevertheless the routine imaging procedure for staging patients with NSCLC although performing a PET scan in addition to this CT examination seems to be a good approach that can reduce but certainly not always avoid invasive staging procedures. Mediastinoscopy is still generally considered the standard of care when tissue needs to be obtained from suspicious nodes on FDG-PET and/or CT, although minimally invasive biopsy techniques could replace to a large extent this more invasive technique in the near future.

Whole-body magnetic resonance imaging

Whole-body magnetic resonance imaging is a fast and accurate modality for the detection of disease throughout the entire body. Technical improvements including the availability of different high image quality MR sequences, the remote movement of the imaging table, and the use of specialized surface coils have rendered whole-body screening with MRI a feasible method. In this article we describe underlying techniques and report on first clinical experiences of whole-body magnetic resonance imaging as a staging and screening method. Furthermore, advantages and limitations compared with whole-body imaging based on computed tomography are discussed.