PET-CT is better for early detection of muscular lymphoma than CT alone, according to a new study conducted by radiologists at the University of Minnesota in Minneapolis.
For the study, PET-CT was used to image 305 patients with lymphoma. Twelve of these patients had muscular involvement in which 10 were biopsy proven and two were proven by imaging follow-up.
According to the study, six of these patients had predominantly muscular lymphoma with or without bone involvement and three had nodal lymphoma and developed muscular involvement on subsequent imaging. Two of the 12 patients had liver metastases and one patient had an extensive malignancy that involved the face and underlying structures. In one case, a lymph node that was persistently enlarged on CT remained negative on all PET studies.
"Our results demonstrate that radiologists should remember that lymphoma can involve muscles, though many radiologists are less diligent in their analysis of musculature in lymphoma cases," said Saravanan Krishnamoorthy, MD, lead author of the study. "Also, the PET abnormalities often precede the CT changes, suggesting that muscle involvement by lymphoma may be an important part of staging that is neglected if only CT is performed," said Dr. Krishnamoorthy.
"This study shows that PET-CT is excellent in identifying lymphoma, both in lymph nodes and in extranodal sites. Therefore, staging will be both more accurate and precise; likewise, response to treatment will be both more accurate and precise," said Dr. Krishnamoorthy.
The full results of this study will be presented on Tuesday, May 8, 2007 during the American Roentgen Ray Society's annual meeting in Orlando, FL.