Clinical impact of FDG-PET/CT in the planning of radiotherapy for early-stage Hodgkin lymphoma.
BACKGROUND
Early-stage Hodgkin lymphoma (HL) has excellent survival rates but carries a high risk of late treatment-related adverse effects. Modern, individualised therapeutic strategies require an accurate determination of the extent of the disease. This study investigated the potential impact of 2-[18F]-fluoro-2-deoxy-d-glucose positron emission tomography/computerised tomogrpahy (FDG-PET/CT) in the planning of involved field radiotherapy (IFRT).


METHODS
Thirty patients received staging FDG-PET/CT before therapy, and IFRT after a short course of ABVD (adriamycin, bleomycin, vinblastine, dacarbazine) chemotherapy. IFRT planning was performed using only the CT data from the FDG-PET/CT scan. Later, the IFRT planning was performed anew using the FDG-PET/CT data as basis for contouring.


RESULTS
In 20 out of 30 patients, the radiotherapy (RT) course was unaffected by the addition of FDG-PET/CT. FDG-PET/CT would have increased the irradiated volume in seven patients where the volume receiving a minimum of 90% of the target dose was increased by 8-87%. FDG-PET/CT decreased the volume in two patients where the volume was reduced by 18% and 30%.


CONCLUSIONS
When used for RT planning, FDG-PET/CT results in larger IFRT treatment volumes. If FDG-PET/CT is introduced to RT planning, the method should be accompanied by a change in RT treatment strategy, aiming at more targeted therapy in order to best avoid radiation to normal tissues.
Hutchings
Martin
M
Department of Clinical Physiology and Nuclear Medicine, PET and Cyclotron Unit, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark. hutchings@dadlnet.dk
Loft
Annika
A
Hansen
Mads
M
Berthelsen
Anne Kiil
AK
Specht
Lena
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006689:Hodgkin Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019788:Fluorodeoxyglucose F18