Positron emission tomography (PET) for staging and evaluation of response to treatment in patients with Hodgkin's disease

Forty two examinations utilizing F-18 FDG-PET were performed in 23 patients with Hodgkin's disease to study for involved lymphoma regions and compared to conventional staging procedures. Twenty stagings were performed at diag nosis of untreated Hodgkin's disease or at first relapse, and 22 restagings during and after chemoradiotherapy. At diagnosis in 5 of 20 patients PET a nd other procedures revealed different extranodal manifestations and in 3 p atients established different clinical staging. PET seemed to be accurate i n the assessment of lymphoma involvement in nodal sites. During follow up, in 10 out of 22 investigations different results and discrepancy were recor ded, mostly due to the different extent of F-18-FDG metabolism in residual masses in lymphatic tissues compared to CT, X-ray or ultrasonography. The r esults indicate that PET may have advantages in the assessment of remission s in nodal sites. Less conclusive results were observed with regard to extr anodal involvement or inflammatory disease. In conclusion PET may be suffic ient for the staging of the majority of patients with Hodgkin's disease and particularly for assessing remission status in nodal sites, but PET may ha ve disadvantages in the evaluation of extranodal lymphoma and inflammatory disease.