Whole body positron emission tomography in the treatment of Hodgkin disease

BACKGROUND. In Hodgkin disease (HD), accurate assessment of the extent of d isease is essential because it provides the basis for different treatment s trategies. In addition to conventional imaging methods (CIM), positron emis sion tomography with fluorine-18-fluorodeoxyglucose (FDG-PET) may permit re liable differentiation between lymphoma and nonmalignant tissue and thus im prove determination of the stage of the disease. The aim of the current stu dy was to asses the clinical value of FDG-PET for primary staging, treatmen t monitoring, and assessment in a suspected case of recurrent HD. METHODS. Eighty-one patients with HD underwent 106 FDG-PET studies using a dedicated whole body PET ring scanner. In 25 patients PET was part of the p rimary staging, 63 PET studies were undertaken for treatment monitoring aft er the completion of treatment, and in 18 patients PET was performed in cas es of suspected recurrence of HD. PET scans were compared with CIM and veri fied histologically and/or by follow-up evaluation (mean follow-up duration , 20.4 months). RESULTS. With regard to primary staging, in a patient to patient analysis, both PET scans and CIM were positive (i.e., showed pathologic foci indicati ve of HD) in 24 of 25 cases. In a staging-relevant lesion to lesion analysi s, accuracy in the determination of the stage of disease was 96% for PET ve rsus 56% for CIM. PET led to a lower stage classification in 28% and a high er stage classification in 12% of cases, compared with the stage assumed wi th CIM. With regard to treatment monitoring, PET showed an accuracy of 91% compared with 62% for CIM. The negative predictive value of PET was 96%. Wi th regard to suspected recurrence, PET findings were true-positive in 10 to 12 PET scans and true-negative in 5 of 6 PET scans, resulting in accuracy of 83%, which compares favorably with the accuracy rate of 56% for CIM. CONCLUSIONS. It may be concluded that FDG-PET is capable of determining the stage of HD with great accuracy and is capable of correctly detecting mani festations of HD in treatment monitoring and cases of suspected recurrence, in which CIM occasionally result in equivocal findings. The results of the current study suggest that FDG-PET should become a routine tool in staging /restaging of HD. (C) 2001 American Cancer Society.