AJR: FDG PET/CT useful in evaluation of T-cell lymphomas
FDG PET/CT should be part of primary staging in patients with T-cell lymphoma and may potentially change disease stage and patient management, according to a study published in the August issue of American Journal of Roentgenology.

The study retrospectively reviewed patients with T-cell lymphomas who underwent a PET/CT exam for initial disease staging or at disease relapse over a five-year period by correlation between a patient database and a PACS radiology information system.

Disease subtypes were grouped according to World Health Organization categorization of mature natural killer cell–T-cell neoplasms by John Feeney, MD, and colleagues at the department of radiology and nuclear medicine services at Memorial Sloan-Kettering Cancer Center in New York City.

Sites of disease involvement were documented by the researchers according to cutaneous or extranodal, nodal and visceral locations. The maximum standardized uptake value (SUV) was recorded for each patient.

The study included 135 patients with T-cell lymphoma, and sites of disease were documented by use of FDG PET/CT in 122 patients. Of those 122 patients, 55 had cutaneous involvement, 95 had FDG-avid lymphadenopathy and 54 had FDG-avid extranodal disease other than cutaneous involvement, according to Feeney and colleagues.

The researchers also found a significant difference in maximum SUV in cases of mycosis fungoides and mycosis fungoides with large cell transformation.

“FDG PET/CT identifies more disease sites than conventional CT does because the scan range is greater,” wrote the authors. "The combination of PET with CT allows greater lesion detection because foci of subtle FDG uptake in skin and subcutaneous tissues may be overlooked unless the simultaneously acquired CT images of the PET/CT are reviewed carefully with particular attention to these areas."

Feeney and colleagues concluded by recommending that patients with T-cell lymphoma be scanned from vertex to feet by use of PET/CT.