The Role of FDG-PET in Hodgkin Lymphoma S/P Autologous Hematopoietic Cell Transplant (HCT) as a Predictor of Outcome.

The role of PET scans in Hodgkin Lymphoma (HL), especially after autologous HCT, is undefined. Positron emission tomographic (PET) scanning has increasingly become a promising non-invasive modality for the monitoring of patients with HL. Whole body PET scans have been reported to have increased sensitivity and accuracy as compared to conventional staging methods for the initial staging of HL. The sensitivity of PET is reported as 86% compared to 37% for CT, while the specificity has been reported as 96.5% compared to 99.7% for CT. The purpose of this study was to investigate the utility of PET scanning in relapsed HL s/p autologous HCT as a prognostic indicator of transplant outcome. Here, we describe a single institution retrospective analysis of 55 patients with HL who had FDG-PET scans after stem cell transplantation. Patients/Methods : Between 1/94 and 12/06, 55 patients with refractory or relapsed Hodgkin Lymphoma underwent an autologous HCT at our institution. They each had a FDG-PET approximately one month following stem cell transplant to evaluate for response following HCT. Patients were placed into two separate categories depending on results of the PET scan. The incidence and timing of relapse, disease free survival, and overall survival were assessed. Results : A total of 55 patients were evaluated post autologous HCT with a median age of 32 years (ranging from 15–66) with a median follow-up of 26 months. The patients were divided into two groups based on FDG-PET activity. Twenty-nine patients had no evidence of activity post transplant, while twenty-six patients had evidence of activity. The median DFS and OS of the PET negative group were 35.8 months and 35.8 months, respectively. The median DFS and OS of the PET positive group were 18.1 months and 10.1 months, respectively. There were statistically significant differences between the two groups when comparing their DFS and OS (p=0.0035 and p=0.004), in favor of the PET negative group. There were 2 relapses in the PET negative group and 9 relapses in the PET positive group (see figures). Conclusion : We conclude that FDG-PET scan performed after autologous HCT for patients with relapsed or refractory Hodgkin lymphoma strongly predicted transplant outcome. Patients with any significant PET uptake are at high risk of treatment failure and should be considered for additional treatment with strong contemplation for participation in clinical trials. ![Figure][1] Figure [1]: pending:yes