Consolidative Radiotherapy After Autologous Stem Cell Transplantation for Relapsed or Refractory Diffuse Large B-cell Lymphoma

Long-term remissions in patients with early relapse of diffuse large B-cell lymphoma following high-dose chemotherapy, autologous stem cell transplantation, and radiotherapy of residual disease

PURPOSE

The prognosis of an early relapse of diffuse large B-cell lymphoma (DLBCL) appears to be poor following autologous stem cell transplantation (ASCT). The aim of this study is to contribute data to the open question on whether additional radiotherapy can improve the outcome.

PATIENTS AND METHODS

Forty-eight patients with an early relapse (median 4 months after the end of initial immunochemotherapy, range 1-11) of DLBCL have been treated in our institution with high-dose therapy (usually the BEAM protocol) and ASCT since 2008 (median age 61 years, range 28-73). Twenty-three patients received ASCT in a second treatment line, 25 in a third line (19 refractory to second-line salvage therapy, 5 after second relapse). Fifteen of these 48 patients received radiotherapy (36-50 Gy, median 40) of residual masses after ASCT.

RESULTS

Three-year overall survival (OS) and progression-free survival (PFS) after second-line ASCT were 61 and 57%, after third-line ASCT 47 and 44%, respectively, without significant differences. A prognostic factor was the International Prognostic Index (IPI) at the start of salvage therapy. Three-year OS and PFS in low-risk patients were 69 and 69%, in low-intermediate-risk 63 and 53%, and in high-intermediate-risk 23 and 23%, respectively (p = 0.033). Twenty-three patients achieved a sustained complete remission (13-146 months, median 62).

CONCLUSION

Sustained long-term remissions can be achieved in patients with early relapse of DLBCL following ASCT in a second or third treatment line, particularly in patients with low- and low-intermediate-risk IPI, following radiotherapy of residual disease after ASCT. Further investigations are required to clarify which patients need an alternative therapy (potentially CAR T‑cells or allogeneic transplantation).

Impact of Radiation Therapy After High Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation in Patients With Relapsed/Refractory Lymphomas: A Single Center Experience

INTRODUCTION

After high dose chemotherapy (HDC) and autologous stem cell transplantation (auto-SCT), in patients with relapsed/refractory diffuse large B cell lymphoma (DLBCL) and Hodgkin lymphoma (HL), involved field radiation therapy (RT) for consolidation and residual/progressive disease (PD) eradication is a common practice.

MATERIALS AND METHODS

Retrospective single-institution cohort analysis to evaluate the impact of early RT after HDC auto-SCT.

RESULTS

Between 1996 and October 2019, 153 patients (43 DLBCL, 110 HL) underwent RT after HDC auto-SCT. Males 95 (62%), females 58 (38%), median age 24 years. Indications for RT was consolidation 65%: residual disease eradication 16%: and PD eradication 19%. For DLBCL, the median overall survival (OS) for the above indications was not reached (NR):NR:2 months and the KM 5-year OS was 72.6%:64.3%:12.5% respectively (P ≤ .000). Pair-wise analysis showed that consolidation versus residual disease eradication had no difference (P = .88) but both were superior to PD disease eradication (P ≤ 000 and P = .005 respectively). For HL, indication for RT was, 54%:23%:24% respectively. The median OS was NR:NR:28.8 months and KM 5-year OS was 82.3%:78%:30% respectively (P ≤ .000). Pair-wise analysis showed that consolidation versus residual disease eradication had no difference (P = .98) but both were superior to the PD eradication group (P ≤ 000). RT was well tolerated with no significant long-term toxicity.

CONCLUSION

Post HDC auto-SCT RT was well tolerated. DLBCL and HL patients with residual disease treated with the RT had similar long-term survival as those who received RT for consolidation. RT failed to improve the poor survival in patients with post-HDC auto-SCT PD.

Favorable Outcome After Adjuvant Involved-Field Radiotherapy After Autologous Hematopoietic Stem-Cell Transplantation in Patients With High-Risk Relapsed/Refractory Lymphoma: A Single-Center Experience

BACKGROUND

Patients with refractory or relapsed lymphoma diagnosed with bulky disease at relapse or with residual disease after salvage treatment are considered to have a dismal outcome, even after autologous hematopoietic stem-cell transplantation, as a result of disease recurrence. To minimize the risk of relapse after receipt of a transplant, involved-field radiotherapy (IFRT) to sites of either bulky or localized residual disease has been utilized; however, the ideal timing for irradiation remains controversial. The aim of this study was to assess the safety and efficacy of IFRT in the early period after transplantation.

PATIENTS AND METHODS

We retrospectively evaluated the outcome of 24 autografted patients with relapsed/refractory lymphoma who presented with bulky disease at relapse or who had a persistent localized residual mass after salvage treatment and consolidated with IFRT within 4 months after autografting.

RESULTS

No significant toxicity was noticed during the early postradiotherapy period, while graft function was not impaired. After a median follow-up of 3 years for survivors, 21 patients were alive, 19 of whom were event free, while 2 patients died of disease recurrence and 1 died of treatment-related myelodysplastic syndrome. The 3-year overall, lymphoma relapse-free, and event-free survival rates were 86%, 86%, and 82%, respectively.

CONCLUSION

Taking into consideration the poor-risk features of the study cohort, IFRT provided early after autologous hematopoietic stem-cell transplantation showed a safe and well-tolerated toxicity profile and demonstrated long-term effective tumor control, as reflected in the promising survival rates.

Response to hyperfractionated accelerated radiotherapy in chemotherapy-refractory non-Hodgkin lymphoma

Patients with chemotherapy-refractory non-Hodgkin lymphoma (NHL) have a poor prognosis with a median overall survival (OS) of only 10 months. To investigate the role of radiotherapy (RT) in such patients, we conducted a retrospective review of 17 patients with biopsy-proven refractory NHL who received hyperfractionated accelerated RT between 2000 and 2017. Forty-seven percent had stages I and II and 53% had stages III and IV disease. Majority (59%) had diffuse large B-cell lymphoma. One-year local control rate was 82%. Fifty-nine percent proceeded to hematopoietic stem cell transplantation (HSCT). At a median follow-up time of 8.8 months (range: 13 days to 17.4 years), 10 were alive with five in remission. Six patients were long-term survivors with a median OS of 8.1 years. Hyperfractionated accelerated RT in chemotherapy-refractory NHL provides durable local disease control in the majority of cases. Combined with HSCT, the RT regimen may also provide long-term disease remission in a subset of patients.