Original contribution
Whole-body diffusion-weighted imaging vs. FDG-PET for the detection of non-small-cell lung cancer. How do they measure up?

https://doi.org/10.1016/j.mri.2010.02.009Get rights and content

Abstract

Objective

To compare the diagnostic efficacy of whole-body diffusion-weighted imaging (WB-DWI) and [18F] fluoro-2-D-glucose PET/CT(FDG-PET/CT)for assessment of non–small cell lung cancer (NSCLC) patients.

Materials and Methods

A group of 56 patients (21 female, 35 male; 35–76 years) with NSCLC proved by pathologic examination or follow-up imaging findings was set as reference standards, and all patients underwent both WB-DWI at 1.5T (MAGNETOM Avanto) and PET/CT (Biograph 16). For WB-DWI, a free breathing diffusion-weighted single-shot spin-echo epi-sequence in five-stations (head-neck, thorax, abdomen, pelvis-thigh) was used. Each station-series contained 30 contiguous axial slices. Imaging parameters: FOV 360×360 mm, matrix size 128×80. B-values: 0 and 1000 s/mm2 applied along x, y and z, 5 averages, acquisition time: 2.23 min/series, total: 11.55 min. The efficacy of WB-DWI and PET/CT were determined in a blinded reading by two radiologists and two nuclear medicine physicians using pathology and size change during follow up exams as the reference standard.

Results

Primary tumors (n=56 patients) were correctly detected in 56 (100%) patients by both PET/CT and WB-DWI. Ninety-six lymph nodes metastases were determined with pathologic and follow-up examinations. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV) being for lymph node metastases: 91%, 90%, 90%, 96%, 80% with WB-DWI and 98%, 97%, 97%, 99%, 93% with PET-CT, other metastases: 90%, 95%, 92%, 97%, 83% with WB-DWI and 98%, 100%, 98%, 100%, 95% with PET-CT). Differences in the accuracy of lymph node metastasis detection between PET/CT and WB-DWI (P=.031) were significant. The differences were not statistically significant for detection of other metastases.

Conclusions

WB-DWI is a feasible clinical technique for the assessment of NSCLC, lymph nodes and metastastic spread with high sensitivity and accuracy, but it was limited in the evaluation of neck lymph node metastases and small metastastic lung nodules.

Introduction

Lung cancer is the leading cause of tumor-related deaths, while non-small cell lung cancer (NSCLC) accounts for 80% of all lung cancers [1], and the selections of therapy for lung cancer are based on the staging of the TNM classification of malignant tumors staging currently. Hence, accurate TNM staging is one of the most valuable parameters for lung cancer diagnosis. Plain film, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) all have been used for this purpose [2]. Past clinical practice has shown that Fluorine 18 fluorodeoxyglucose positron emission tomography/CT (FDG PET/CT) possesses substantially higher sensitivity and specificity in TNM staging for NSCLC, presenting better efficacy for staging lung cancer than CT or PET alone [3], [4], [5], [6], [7], although expensive and radioactive ions such as fluorine-18-2-fluoro-2-deoxy-d-glucose are its disadvantages. Whole-body MRI (WB-MRI) has been put forward as another whole-body technique for the assessment of distant metastases in patients with malignant tumor [8], [9], [10], [11]. Recently, it has been reported that WB-MRI was superior to skeletal scintigraphy tumor skeletal metastases and M stage assessment for NSCLC [12], [13], and literatures suggesting diffusion-weighted (DW) imaging could be useful for the assessment of primary malignancy and lymph node and/or distant metastases were published [14], [15], [16], [17], [18]. Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) has been introduced for 1.5-T MR scanners by Takahara et al. [19] In the DWIBS approach, it allows three-dimensional (3D) reconstructions like maximum intensity projection (MIP), obtaining PET-like three-dimensional images, on which 3D distributions of lesions can be recognized [19].To evaluate value of the whole-body DW imaging (WB-DWI) in NSCLC, we designed this study to determine the accuracy of WB-DWI for assessment of non-small cell lung cancer (NSCLC) patients by comparing with FDG PET/CT.

Section snippets

Subjects

The study was approved by the Ethics Committee of Southwest hospital, and written consent forms were obtained from all participants. From January to March in 2008, 56 consecutive patients with NSCLC underwent WB-DWI and integrated FDG PET/CT for primary tumor, lymph node metastasis and distant metastasis; all patients were confirmed by pathologic examination or follow-up imaging findings for reference standards [21 female, 35 male; 35–76 years old (mean age, 51years] were included.

WB-DWI

All patients

Primary tumors

The distribution of primary tumors in 56 patients were as follows: right upper lobe in 18 patients, right middle lobe in nine patients, right lower lobe in 12 patients, left upper lobe in 11 patients and left lower lobe in six patients. Tumor sizes were 2.2–6.3 cm, and all of which were correctly detected by WB-DWI and PET/CT. The abnormal concentration on PET/CT and highly intensified signal on WB-DWI was the typical presentation of primary tumors (see Fig. 1).

Lymph nodes

A total of 135 lymph enlarged

Discussion

The regimen selection of NSCLC treatment and its prognosis are strongly influenced by lymph node and distant metastases. Although CT has been considered the standard modality for the assessment of metastases of lung cancer, PET/CT is the primary tool for lung cancer staging, and it has been shown to be substantially more sensitive and specific in the detection and characterization of metastases to mediastinal lymph nodes, which possesses unique value in identifying distant metastases that are

References (33)

  • ShimS.S.

    Non-small cell lung cancer: prospective comparison of integrated FDG PET/CT and CT alone for preoperative staging

    Radiology

    (2005)
  • LauensteinT.C.

    Whole-body MR imaging: evaluation of patients for metastases

    Radiology

    (2004)
  • WalkerR.

    Turbo STIR magnetic resonance imaging as a whole-body screening tool for metastases in patients with breast carcinoma: preliminary clinical experience

    J Magn Reson Imaging

    (2000)
  • Daldrup-LinkH.E.

    Whole-body MR imaging for detection of bone metastases in children and young adults: comparison with skeletal scintigraphy and FDG PET

    AJR Am J Roentgenol

    (2001)
  • OhnoY.

    Whole-body MR imaging vs. FDG-PET: comparison of accuracy of M-stage diagnosis for lung cancer patients

    J Magn Reson Imaging

    (2007)
  • NakanishiK.

    Whole-body MRI for detecting metastatic bone tumor: diagnostic value of diffusion-weighted images

    Magn Reson Med Sci

    (2007)
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