Feasibility, toxicity and response of upfront metaiodobenzylguanidine therapy therapy followed by German Pediatric Oncology Group Neuroblastoma 2004 protocol in newly diagnosed stage 4 neuroblastoma patients.

Aim Of The Study: Radiolabelled meta-iodobenzylguanidine (MIBG) is an effective option in treatment of neuroblastoma (NBL) tumours. We studied feasibility, toxicity and efficacy of upfront I-MIBG and induction treatment in stage 4 NBL patients.

Patients And Methods: Retrospective, multi-centre (AMC and EMC) pilot regimen (1/1/2005-2011). Newly diagnosed stage 4 NBL patients, were treated with 2 courses of I-MIBG, GPOH 2004 NBL protocol, myeloablative therapy (MAT) and autologous stem cell rescue (ASCT). I-MIBG was administered in a fixed dose. Response rate (RR) was defined as complete remission, very good partial response and partial response.

Results: Thirty-two patients, (median age [range] 2.9 [0-11.4] years), 21 received I-MIBG therapy, 11 did not because of: MIBG non-avid (N = 5) and poor clinical condition (N = 6). In 95% of eligible patients I-MIBG treatment was feasible within 2 weeks from diagnosis. Interval between chemotherapy courses was 25 days (I-MIBG group) versus 22 days (chemotherapy group). No stem cell support was needed after I-MIBG therapy. Stem cell harvest in both groups was feasible, neutrophil recovery was comparable, but platelet recovery post MAT, ASCT was slower for I-MIBG-treated patients. RR post I-MIBG was 38%, post MAT + ASCT was 71% (I-MIBG group), 36% (chemotherapy group) and overall 59%.

Conclusions: Induction therapy with I-MIBG before the HR GPOH NB 2004 protocol is feasible, tolerable and effective in newly diagnosed stage 4 NBL patients. I-MIBG upfront therapy induces early responses.