Whole-body MRI and PET/CT can miss many metastases

German researchers were stunned to discover that whole-body staging of patients with recently diagnosed malignancies using either MRI or PET/CT could miss a substantial number of metastatic lesions. They released their data at the 2007 RSNA meeting.

Dr. Florian Vogt and colleagues at the University Hospital of Essen enrolled 60 consecutive patients who underwent whole-body 1.5T MRI and whole-body FDG-PET/CT for staging of regional and distant melanoma metastases after primary tumor resection. Fifty-six patients completed the mean follow-up of 748 days. The researchers found that a significant number of patients initially staged as negative eventually proved to have undetected metastatic disease.

Another research group from Essen led by Dr. Gerald Antoch also evaluated the accuracy of whole-body FDG-PET/CT and whole-body MRI for staging and detection of bone metastases in 55 patients with melanoma and 54 with non-small cell lung cancer. The investigators found that, despite their accuracy for detection and staging, both tests yielded a significant rate of false negatives.