Carbon-ion radiotherapy alone vs. standard dose photon radiation with carbon-ion radiotherapy boost for high-grade gliomas: a retrospective study.

BACKGROUND

This study aimed to compare the survival outcome and side effects in patients with primary high-grade glioma (HGG) who received carbon ion radiotherapy (CIRT) alone or as a boost strategy after photon radiation (photon + CIRT).

PATIENTS AND METHODS

Thirty-four (34) patients with histologically confirmed HGG and received CIRT alone or Photon + CIRT with concurrent temozolomide between 2020.03-2023.08 in Wuwei Cancer Hospital & Institute, China were retrospectively reviewed. Overall survival (OS), progression-free survival (PFS), and acute and late toxicities were analyzed and compared.

RESULTS

Eight WHO grade 3 and 26 grade 4 patients were included in the analysis. The median PFS in the CIRT alone and Photon + CIRT groups were 15 and 19 months respectively for all HGG cases, and 15 and 17.5 months respectively for grade 4 cases. The median OS in the CIRT alone and Photon + CIRT groups were 28 and 31 months respectively for all HGG cases, and 21 and 19 months respectively for grade 4 cases. No significant difference in these survival outcomes was observed between the CIRT alone and Photon + CIRT groups. Only grade 1 acute toxicities were observed in CIRT alone and Photon + CIRT groups. CIRT alone group had a significantly lower ratio of acute toxicities compared to Photon + CIRT (3/18 vs. 9/16, p = 0.03). No significant difference in late toxicities was observed.

CONCLUSION

Both CIRT alone and Photon + CIRT with concurrent temozolomide are safe, without significant differences in PFS and OS in HGG patients. It is meaningful to explore whether dose escalation of CIRT might improve survival outcomes of HGG patients in future randomized trials.