BACKGROUND

Diffusion-weighted whole-body imaging with background suppression (DWIBS) is used for the diagnosis and staging of cancers. The medical cost of an MR examination including DWIBS is $123, which is 80% less expensive than the cost ($798) of F18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) examination.

METHODS

This study examined the efficacy of DWIBS for relapses after lung cancer resection. A total of 55 patients who had pulmonary resection of lung cancer, postoperative computed tomography (CT) every six months, and DWIBS and FDG-PET/CT (every year) were enrolled in this study. If a metastatic lesion was detected on CT scan, DWIBS and FDG-PET/CT were also used.

RESULTS

A total of 55 patients who underwent pulmonary resections for lung cancer, and had CT, DWIBS and FDG-PET/CT examination during follow-up after pulmonary resection were enrolled in this study. Lung cancer in 32 patients relapsed. Postoperative radiographic examinations revealed pulmonary metastases in 17 patients, bone metastases in seven, liver metastases in five, lymph node metastases in five, pleural metastases in four, metastases to the chest wall in two, brain metastases in two, adrenal gland metastasis in one, and renal metastasis in one. The mean apparent diffusion coefficient (ADC) value of the relapse was 0.9 to 1.70 × 10 mm /s. The accuracy 0.98 (54/55) of DWIBS for detecting multiple metastatic lesions was likely to be higher than 0.94 (52/55) of CT or 0.94 (52/55) of FDG-PET/CT, but there were no significant differences.

CONCLUSIONS

DWIBS can detect multiple metastatic lesions throughout the entire body and differentiate malignancy from benignity in only one examination. DWIBS has benefits of diagnostic accuracy and is less expensive in medical costs for the detection of a relapse. DWIBS could potentially replace FDG-PET/CT after lung cancer resection.