Agreement rates among single photon emission computed tomography using gallium-67, computed axial tomography and lymphangiography for Hodgkin diseaseand correlation of image findings with clinical outcome

BACKGROUND. This study was undertaken to systematically evaluate the agreem ent rates among single photon emission computed tomography using gallium-67 (Ga-67 SPECT), lymphangiography (LAG), and computed axial tomography (CT) scan findings for Hodgkin disease and to correlate radiologic findings with clinical outcome. METHODS. One hundred three previously untreated patients with Hodgkin disea se who had Ga-67 SPECT scan between August 1992 and December 1994 at our in stitution form the basis of this study. The agreement rates among Ga-67 SPE CT, LAG, and CT scan findings were calculated by sites from the pretreatmen t evaluation throughout the courses of chemotherapy. The probabilities of r ecurrence or progression by sites were correlated with the radiologic findi ngs. RESULTS. The median follow-up was 3 years. The pretreatment agreement range d from 75% to 100% between Ga-67 SPECT and CT scans, 85-100% between CT sca n and LAG, and 74-99% between Ga-67 SPECT and LAG. A greater variation in a greement was observed once chemotherapy was started, the site with the leas t agreement being the mediastinum. The most common site of the recurrence o r progression was also the mediastinum. When the CT scan showed persistent abnormality even after Ga-67 SPECT turned negative after chemotherapy, the chances of mediastinal recurrence or progression were 3 in 34 and 3 in 18 a fter 1-3 cycles and 4-6 cycles, respectively. CONCLUSIONS. Although there was a relatively high correlation between Ga-67 SPECT and the other modalities, the intrinsic limitation of planar Ga-67 w as still observed in Ga-67 SPECT especially in the mediastinum. There was s till a moderate risk of mediastinal recurrence or progression even after re sidual CT scan abnormality lost gallium avidity from chemotherapy. (C) 2000 American Cancer Society.