Comparison of toxicity following single versus tandem autologous transplant regimens for pediatric medulloblastoma

Background: Medulloblastoma outcomes have improved with craniospinal irradiation and chemotherapy, but such therapy has resulted in poor neurocognitive outcomes for young patients. Chemotherapy-only regimens with autologous transplant have been implemented with the intention of avoiding radiation. It is not yet known whether single or tandem transplantation is superior with respect to efficacy and/or safety. Methods: We performed a retrospective review of children with medulloblastoma treated at Dana-Farber Cancer Institute from 1996 to 2016 who received either single or tandem autologous transplantation after completion of induction chemotherapy. We compared safety and outcome data between the two groups. Results: Among 23 patients, 12 received tandem transplants. Median follow-up was 6.4 years (IQR = 0.8–10.5). There was no statistically significant difference in 5-year EFS or OS between the single (70.7 ± 14%, 80.2 ± 13%) and tandem transplant groups (57.1 ± 15%, 79.6 ± 13%). Seven tandem transplant patients received subsequent radiation while only four required radiation in the single transplant group (p =.41). In the single transplant regimen, patients experienced longer antibiotic duration (p =.03) and LOS (p =.01) and a trend toward increased number of transfusions (p =.06). Four cases of veno-occlusive disease were reported in the single transplant group (p =.04). Conclusions: Outcomes were similar between regimens, but the single transplant regimen had more hepatic complications. These data suggest that tandem transplant regimens may have reduced toxicity compared to the single transplant regimen with similar outcome measures.