A 55-year-old man with newly diagnosed glioblastoma (GBM) is started on the Stupp protocol. What is the correct dosing schedule for concurrent temozolomide during the radiotherapy phase?
- A 200 mg/m² on days 1-5 every 28 days
- B 150 mg/m² on days 1-5 every 28 days
- C 75 mg/m² daily throughout radiotherapy ✓
- D 50 mg/m² on alternate days during radiotherapy
Correct answer: C. 75 mg/m² daily throughout radiotherapy
Explanation
The Stupp protocol uses concurrent temozolomide at 75 mg/m² daily throughout 6 weeks of radiotherapy, followed by adjuvant temozolomide at 150-200 mg/m² on days 1-5 every 28 days for 6 cycles. Options B and A describe the adjuvant phase dosing. The concurrent daily dosing is radiosensitizing and is the key distinction tested.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.