Sign Up

LOGIN / SIGNUP

The standard treatment regimen for newly diagnosed glioblastoma multiforme (GBM) involves concurrent chemoradiotherapy with temozolomide followed by adjuvant temozolomide. Here is a detailed overview of the regimen, including dosages, cycles, and potential toxicities:

Concurrent Chemoradiotherapy

Radiotherapy

  • Dose: 60 Gy delivered in 30 fractions of 2 Gy each, administered five days a week (Monday through Friday) over six weeks.

Temozolomide (Concurrent Phase)

  • Dose: 75 mg/m² of body surface area per day.
  • Schedule: Administered daily, including weekends, from the first to the last day of radiotherapy, for a maximum of 49 days.

Adjuvant Chemotherapy

Temozolomide (Adjuvant Phase)

  • Cycle 1 Dose: 150 mg/m² per day.
  • Subsequent Cycles Dose: Increased to 200 mg/m² per day if no significant hematologic toxicities are observed.
  • Schedule: Administered on days 1 to 5 of a 28-day cycle.
  • Number of Cycles: Typically up to six cycles, but may be extended to 12 cycles depending on patient response and tolerance.

Toxicities and Management

Common Toxicities

  • Hematologic: Myelosuppression, including neutropenia and thrombocytopenia, is common. Grade 3-4 hematologic toxicities occur in a significant minority of patients.
  • Non-Hematologic: Nausea, vomiting, fatigue, and constipation are frequently reported. Prophylactic antiemetics may be used to manage nausea and vomiting.

Severe Toxicities

  • Infections: Due to potential lymphocytopenia, patients are at increased risk for opportunistic infections, such as Pneumocystis jiroveci pneumonia. Prophylactic antibiotics are recommended.
  • Long-term Risks: There is a risk of secondary malignancies and myelodysplastic syndrome with prolonged use.

Monitoring and Adjustments

  • Blood Counts: Regular monitoring of complete blood counts is essential to detect and manage myelosuppression.
  • Dose Adjustments: Dose reductions or delays may be necessary based on the severity of toxicities, particularly hematologic ones.

This regimen is based on clinical trials and guidelines, and individual treatment plans may vary based on patient-specific factors such as age, performance status, and genetic markers like MGMT promoter methylation status. Always consult with a healthcare professional for personalized treatment planning.