Comparison of carbon ion and photon reirradiation for recurrent glioblastoma

Abstract

Purpose Purpose of this study was to investigate overall survival in recurrent glioblastoma treated with either carbon ion reirradiation or photon reirradiation. Materials and methods In this retrospective study we evaluated 78 consecutive patients with recurrent IDH (Isocitrate dehydrogenase)-wildtype glioblastoma (38 patients carbon ion re-radiotherapy, 40 patients photon re-radiotherapy) treated with either carbon ion reirradiation or stereotactic photon reirradiation. 45 Gy (RBE; 15 fractions) carbon ion reirradiation (CIRT) or 39 Gy (13 fractions) photon reirradiation (FSRT) was administered, respectively. Overall survival was investigated with respect to histological, clinical, and epidemiological features. Kaplan–Meier and multivariate Cox statistics were calculated. A propensity score-matched analysis of the FSRT and CIRT groups using variables from a validated prognosis score was carried out. Results The type of reirradiation (CIRT vs. FSRT) significantly influenced overall survival—8.0 months vs. 6.5 months (univariate: p = 0.046)—and remained an independent prognostic factor in multivariate analysis (p = 0.017). Propensity score-adjusted analysis with CIRT versus FSRT as the dependent variable yielded a significant overall survival advantage for the CIRT group (median OS 8.9 versus 7.2 months, p = 0.041, 1‑year survival 29 versus 10%). Adverse events (AE) were evaluated for both subgroups. For the FSRT group no toxicity ≥ grade 4 occurred. For the CIRT subgroup no grade 5 AE occurred, but 1 patient developed a grade 4 radionecrosis. We encountered 4 grade 3 toxicities. One patient developed a zoster at the trunk, 2 progressed in their paresis, and 1 featured progressive dysesthesia. Conclusion In conclusion, carbon ion treatment is a safe and feasible treatment option for recurrent glioblastoma. Due to the retrospective nature of the study and two different dose levels for CIRT or FSRT, the improved outcome in CIRT reirradiation might be an effect of higher biological impact from carbon ions or a simple dose-escalation effect. This hypothesis needs prospective testing in larger patient cohorts. A prospective phase III randomized trial is in preparation at our center.

The use of radiosensitizing agents in the therapy of glioblastoma multiforme—a comprehensive review

“…Further randomized trials with larger patient numbers are needed [ 103 ], but the complexity of the treatment as well as the required infrastructure seem to be considerable roadblocks in this regard [ 100 ]. The concept of particle irradiation for glioblastoma patients is also a present topic in contemporary research [ 104 ]. Table 13 summarizes the published trials evaluating BNCT in glioblastoma treatment.…”

Outcomes of Isocitrate Dehydrogenase Wild Type Glioblastoma after Re-irradiation

“…Notably, IDH status was not reported, which may have led to the inclusion of more favorable IDH-mutant tumors, explaining the prolonged median OS compared to this cohort. Another analysis reported treatment outcomes in IDH-wt tumors after photon and carbon ion re-irradiation [17] . Favorable results, i.e., longer OS, were observed for carbon ion treatments, but applied doses were higher compared to photon irradiations, impeding further conclusions.…”

Combined BNCT-CIRT treatment planning for glioblastoma using the effect-based optimization

“…patient 6), the combined BNCT-CIRT treatment may not achieve acceptable results due to the high cost of delivering dose/ effect into the deep CTV using the BNCT approach. Multi-field CIRT may be a more suitable choice in such cases (Lautenschlaeger et al 2022).…”