I saw this talk mentioned in ANR this year:
Methods: The aim of this analysis was 1) to investigate local control and event-free survival (EFS) in the full cohort of 1467 patients (stage 4: 1180, MNA: 170, unknown: 117) having received irradiation according to the HR-NBL1/SIOPEN trial recommendation after high dose chemotherapy and autologous stem cell reinfusion between 2002-2015. 2) to correlate local control with RTQA in the subset of 100 patients with previously performed RTQA. Results: In the group of 1467 patients no difference was detected neither in the cumulative incidence of local relapse nor in event-free survival between patients receiving < 21Gy, 21Gy as prescribed or > 21Gy. However, only in the subgroup of 170 patients with localized MNA disease a trend towards improved 5-year EFS was observed in patients receiving 21Gy as prescribed in contrast to those patients who did not (5yr-EFS:70% versus 62%). In the subset of 100 patients with previous RTQA a significantly increased local recurrence rate of 44% (10/23pts) was found when RT had not been delivered according to protocol in contrast to 22% (17/77pts) in patients treated with correct volume and dose (p=0,042). Conclusion: These early results show the importance of RTQA for local control in the treatment of neuroblastoma. Further confirmation in a larger patient population is currently being performed. Prospective central validation of RT planning prior to RT delivery could improve overall disease control.
There is very little literature out there about proton therapy benefits for NB, however this is what MSKCC use, as a parent it is really terrible to hear that your child is going to be 4.5cm shorter due to this treatment, proton therapy will decrease the amount of spine radiation which in turn means less height is lost.
MSKCC recently moved to 18Gy from 21Gy in some cases, there is a published paper about this perhaps discuss it with your radiotherapy consultant. Keep in mind odds of anyone straying from protocol on SIOPEN approach zero, and honestly you don’t really want to taking on the responsibility of experimenting in this department.
There have been quite a few papers over the years highlighting the importance of radiotherapy during HRNB treatment, it is considered a very important aspect of the treatment. There is this old COG study that many would refer to.