Moderately Hypofractionated Concurrent Chemoradiotherapy for High-Grade Glioma: A Prospective Observational Study of Early Response and Treatment Toxicity

Background: High-grade gliomas (HGG) are aggressive primary brain tumours with poor outcomes despite multimodal treatment. Hypofractionated radiotherapy may shorten treatment duration while maintaining clinical effectiveness. This study evaluated the early radiological response, treatment tolerability, and haematological toxicity of hypofractionated concurrent chemoradiotherapy in adults with HGG. Material and Methods: This prospective observational study included 30 patients aged 21-59 years with histologically confirmed HGG treated at a tertiary care centre. Patients underwent surgery followed by hypofractionated radiotherapy delivering 58.5 Gy in 25 fractions over 5 weeks, with concurrent temozolomide at 75 mg/m2/day. Adjuvant temozolomide was subsequently administered at 150-200 mg/m2 for 5 days every 28 days. Radiological response was assessed using contrast-enhanced MRI classified according to RECIST version 1.1. Toxicities were graded according to the Common Terminology Criteria for Adverse Events version 5.0. Results: The proportion of lesions measuring <2 cm increased from 23.3% at baseline to 73.3% at 3 months (p<0.0001). At 3 months, 3.3% of patients had a near-complete response, 20.0% had a partial response, 73.3% had stable disease, and 3.3% had progressive disease. Treatment was well tolerated, with no grade 3-4 haematological toxicities, thrombocytopenia, treatment interruptions, or dose adjustments. Neurological symptoms remained infrequent during follow-up. Conclusion: Moderately hypofractionated concurrent chemoradiotherapy with temozolomide demonstrated encouraging early radiological response, excellent treatment compliance, and minimal acute toxicity in adults with HGG. Its shorter treatment duration may improve radiotherapy resource utilisation and reduce patient burden, particularly in resource-limited settings. Larger comparative studies with longer follow-up are needed to establish long-term survival and late toxicity outcomes.

Keywords: High-grade glioma; Hypofractionated radiotherapy; Concurrent chemoradiotherapy; Temozolomide; Radiological response; Treatment toxicity.