This study was conducted to investigate the prognostic effect and implications of gallium 67 scintigraphy (gallium scan) at mid-treatment and at the end of first-line treatment in patients with early- and advanced-stage Hodgkin's lymphoma (HL). A total of 216 HL patients were included in the study. Gallium scan was performed at mid-treatment and at the end of first-line treatment. The overall survival (OS) and event-free survival (EFS) were calculated using the Kaplan-Meier method. The log-rank test was used to identify univariate predictors of EFS and OS. For early-stage disease, bulky mediastinal involvement (yes vs. no, 98 vs. 79%, respectively; P=0.01), erythrocyte sedimentation rate (good vs. adverse, 98 vs. 88%, respectively; P=0.03), presence of B symptoms (no vs. yes, 94 vs. 78%, respectively; P=0.006), post-chemotherapy disease status [complete response (CR) vs. unconfirmed CR (uCR) vs. partial response (PR) vs. progressive disease (PGR), 95 vs. 90 vs. 87 vs. 0%, respectively; P<0.01] and gallium scan at mid-treatment and at the end of treatment (negative vs. positive, 88 vs. 20%, P<0.001; and 85 vs. 10%, P<0.001, respectively) significantly affected the EFS. In addition, age (<50 vs. ≥50 years, 96 vs. 78%, respectively; P=0.01), presence of B symptoms (no vs. yes, 97 vs. 87%, respectively; P=0.03), post-chemotherapy disease status (CR vs. uCR vs. PR vs. PGR, 95 vs. 90 vs. 90 vs. 0%, respectively; P<0.01) and gallium scan results at mid-treatment and at the end of treatment (negative vs. positive, 87 vs. 60%, P<0.001; and 95 vs. 0%, P<0.001, respectively) significantly affected the OS. For advanced-stage disease, Hassenclever index (1-3 vs. 4-6, 80 vs. 57%, respectively; P=0.05) and gallium scan results at mid-treatment and at the end of treatment (negative vs. positive, 84 vs. 18%, P<0.001; and 84 vs. 0%, P<0.001, respectively) significantly affected the EFS, whereas age at diagnosis (<50 vs. ≥50 years, 92 vs. 78%, respectively; P=0.04), Hassenclever index (1-3 vs. 4-6, 86 vs. 61%, respectively; P=0.04) and gallium scan results at mid-treatment and at the end of treatment (negative vs. positive, 98 vs. 40%, P<0.001; and 97 vs. 23%, P<0.001, respectively) significantly affected the OS. On the multivariate analysis, gallium scan at the end of first-line treatment retained statistical significance in terms of EFS and OS. In conclusion, post-chemotherapy gallium scan is an important prognostic factor in patients with early- or advanced-stage HL and a predictor of adverse outcome.
Keywords: Hodgkin's lymphoma; gallium scan; prognostic factors; risk factors.