AUTHOR=Chavaz Lara , Janssens Geert O. , Bolle Stephanie , Mandeville Henry , Ramos-Albiac Monica , Van Beek Karen , Benghiat Helen , Hoeben Bianca , Morales La Madrid Andres , Seidel Clemens , Kortmann Rolf-Dieter , Hargrave Darren , Gandola Lorenza , Pecori Emilia , van Vuurden Dannis G. , Biassoni Veronica , Massimino Maura , Kramm Christof M. , von Bueren Andre O. 

TITLE=Neurological Symptom Improvement After Re-Irradiation in Patients With Diffuse Intrinsic Pontine Glioma: A Retrospective Analysis of the SIOP-E-HGG/DIPG Project

JOURNAL=Frontiers in Oncology

VOLUME=Volume 12 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.926196

DOI=10.3389/fonc.2022.926196

ISSN=2234-943X

ABSTRACT=Purpose 
To investigate the spectrum of neurological triad improvement in patients with diffuse intrinsic pontine glioma (DIPG) treated by re-irradiation (re-RT) at first progression.
Methods 
Re-analysis of the SIOP-E retrospective DIPG cohort by investigating the clinical benefits after re-RT with focus on the neurological triad (cranial nerve deficits, ataxia, and long tract signs). Patients were divided as "responding" or "non-responding" to re-RT. To assess the interdependence between patients’ characteristics and clinical benefits we used a Chi-Square or Fisher’s Exact test. Survival according to clinical response to re-RT was calculated by the Kaplan-Meier method.
Results 
As earlier reported, 77% (n = 24/31) of patients had any clinical benefit after re-RT. Among 25/31 well documented patients, 44% (n=11/25) had improvement in cranial nerve palsies, 40% (n=10/25) in long-tract signs, 44% (11/25) in cerebellar signs. Clinical benefits were observed in at least 1, 2 or 3 out of 3 symptoms of the DIPG triad, in 64%, 40% and 24% respectively. Patients irradiated with a dose ≥ 20 Gy versus < 20 Gy may improve slightly better with regards of ataxia (67% versus 23%; P-value = 0.028). The survival from the start of re-RT to death was not different between responding and non-responding DIPG patients (P-value = 0.871).
Conclusion 
A median re-irradiation dose of 20 Gy provides a neurological benefit in two-third of patients with an improvement of at least one symptom of the triad. DIPG patients receiving ≥20 Gy appear to improve slightly better with regards of ataxia, however we need more data to determine whether dose escalation up to 30 Gy provides additional benefit.