Photo Credit: Nemes Laszlo

The following is a summary of “Short-course hypofractionated proton beam therapy, incorporating ¹⁸F-DOPA PET and contrast-enhanced MRI targeting, for patients aged 65 years and older with newly diagnosed glioblastoma: a single-arm phase 2 trial,” published in the November 2024 issue of Oncology by Vora et al.    

In older patients Glioblastoma (aged ≥65 years) has poor prognosis, with median survival of 6–9 months. 3,4-Dihydroxy-6-[¹⁸F]fluoro-L-phenylalanine (¹⁸F-DOPA) positron emission tomography (PET) and proton beam therapy may improve targeting and outcomes. 

Researchers conducted a prospective study to assess the effect of ¹⁸F-DOPA PET-guided, hypofractionated proton beam therapy on survival in older patients with newly diagnosed glioblastoma. 

They enrolled patients aged ≥65 years with newly diagnosed WHO grade 4 malignant glioblastoma and an Eastern Cooperative Oncology Group (ECOG) performance status of 0–2. Radiotherapy was guided by ¹⁸F-DOPA PET and contrast-enhanced MRI. Patients received hypofractionated proton beam therapy (35–40 Gray equivalents in 5 or 10 treatments) with concurrent oral temozolomide (75 mg/m² daily) and adjuvant temozolomide (150–200 mg/m² 6 for 28-day cycles). The primary endpoint was OS at 12 months, assessed in the intention-to-treat population. 

The results showed that 56% (95% CI 39–72) of 39 patients were alive at 12 months, median OS was 13.1 months (95% CI 11.1–19.1). Grade 3 baseline-adjusted treatment-associated AEs included central nervous system necrosis (4 [10%] of 39 patients) and thrombocytopenia (1 [3%] of 39 patients). No baseline-adjusted treatment-associated grade 4 AEs or deaths occurred. 

They concluded that hypofractionated proton beam therapy with ¹⁸F-DOPA PET guidance improved survival and demonstrated a promising AE profile in patients with older glioblastoma. 

Source: thelancet.com/journals/lanonc/article/PIIS1470-2045(24)00585-0/abstract