Impact of [18f] fluorodeoxyglucose positron emission tomography on staging and management of early-stage follicular non-hodgkin lymphoma.
OBJECTIVE
Accurate staging is critical to select patients with early-stage (I-II) follicular lymphoma (ESFL) suitable for involved-field radiotherapy (IFRT) and to define the radiotherapy portal. We evaluated the impact of fluorodeoxyglucose (FDG) PET on staging, treatment, and outcome for patients with ESFL on conventional staging.


METHODS
Forty-two patients with untreated ESFL (World Health Organization Grade I-IIIa, or "low grade") following a minimum of physical examination, computerized tomography, and bone marrow examination (conventional assessment) and who had staging PET from June 1997 to June 2006 were studied retrospectively. Stage allocation was based on routine imaging reports. Disease sites, stage, and management plan were recorded based on conventional assessment or conventional assessment plus PET.


RESULTS
FDG avidity was demonstrated in 97% of patients in whom disease was evident on conventional assessment after biopsy. PET findings suggested a change of stage or management in 19 patients: 13 (31%) who were upstaged to Stage III-IV, altering ideal management from IFRT to systemic therapy, and 6 (14%) who had the involved field enlarged, including 4 upstaged from Stage I to II. Of these 19 cases, PET findings were considered true positive in 8 patients, indeterminate in 10, and false positive in only 1 patient.


CONCLUSIONS
Our data confirm that ESFL is usually FDG-avid. In routine practice, PET has the potential to upstage and thereby alter management in a high proportion of patients with apparent ESFL.
Wirth
Andrew
A
Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia. andrew.wirth@petermac.org
Foo
Marcus
M
Seymour
John F
JF
Macmanus
Michael P
MP
Hicks
Rodney J
RJ
D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008224:Lymphoma, Follicular / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18