Prognostic potential of positron emission tomography (PET) prior and after autologous stem cell transplant (ASCT) for chemoresistant Hodgkin lymphoma
2Haematology Department, City Clinical Hospital №31, St.Petersburg, Russia
3S.M.Kirov Military Medical Academy, St.Petersburg, Russia
Contact: Dr. Vsevolod G.Potapenko, City Clinical Hospital №31, St.Petersburg, Russia
Accepted 22 September 2016
Aim of the study
To evaluate prognostic significance of pre- and post-transplant PET-scans in patients with relapsed or refractory Hodgkin disease.
Patients and methods
The retrospective data on 84 consecutive patients receiving high dose chemotherapy with АSCT were analyzed. Their median age was 26.6 (10-62) years. Median follow-up was 25 (1-85) months. Conditioning regimens were as follows: ВЕАМ (n=48), BEAM with bendamustine (n=32), CBV (n=4). Pre-transplant PET scanning (PET1) was performed in 83 pts. In 57 cases, repeated PET scans have been carried out (PET2). Survival was estimated using Kaplan–Meier method.
Two-year overall and event-free survival rates were 70.6% and 58.7% respectively. Patients with CT-confirmed progression prior to ASCT had a worse prognosis. Predictive value of PET-status was shown in chemosensitive patients (partial/ complete response by CT-scan). The overall and event-free survival rates in PET1-negative and PET1-positive patients were 82% vs 62% (р=0.056) and 74% vs 44% (р=0.003), respectively. In PET2-negative and PET2-positive patients, overall and event-free survival were 90% vs 65% (р=0.013), and 72% vs 52% (р=0.014), respectively. Event-free and overall survival for PET1+PET2- group didn’t differ significantly from appropriate level in PET1- patients. Prognostic significance of PET2 was superior to predictive value of PET1 results.
CT-chemosensitivity exceeds PET in the prognostic significance. Patients with CT-proven response may benefit from PET scanning. While overall prognosis of PET-positive patients is worse, an additional post-transplant PET may be performed for further risk stratification. The PET1+PET2+ group is at higher risk, with regard of probable relapse.
Positron emission tomography (pet), autologous stem cell transplantation (asct), hodgkin’s lymphomas