What is the dosing of the St. Jude (St. Jude Children's Research Hospital) protocol for average-risk medulloblastoma?

St. Jude Protocol Dosing for Average-Risk Medulloblastoma

For average-risk medulloblastoma, the St. Jude protocol consists of weekly vincristine during craniospinal irradiation (23.4 Gy CSI with involved field boost to 54 Gy), followed by maintenance chemotherapy with vincristine, cisplatin, and cyclophosphamide. 1

Radiation Therapy Component

• Craniospinal irradiation (CSI): 23.4 Gy to the craniospinal axis 1, 2
• Involved field boost: Additional radiation to 54 Gy total dose to the primary tumor site 1, 2
• Concurrent chemotherapy: Weekly vincristine administered during the 6-week radiation period 1, 3

Maintenance Chemotherapy Regimen

The St. Jude maintenance protocol uses a three-drug combination of vincristine, cisplatin, and cyclophosphamide (in contrast to the COG protocol which alternates between cisplatin/lomustine/vincristine and cisplatin/cyclophosphamide/vincristine). 1

Key Protocol Features

• The St. Jude protocol was validated in a study of 330 patients with average-risk medulloblastoma 1
• Group 4 tumors comprised the largest molecular subtype proportion in this trial 1
• Outcomes were comparable to other prospective studies, supporting its use as a standard option 1

Critical Monitoring Requirements

Monitor closely for two dose-limiting toxicities throughout treatment: 2, 3

• Vincristine-associated peripheral neuropathy - assess neurologic function regularly 2, 3
• Cisplatin-associated ototoxicity - perform audiologic evaluation at baseline and regularly during treatment 2, 3

Important Protocol Considerations

Non-Interchangeability Warning

The St. Jude and COG protocols are NOT interchangeable - you must commit to one protocol and complete it as designed. 1 Mixing protocols may compromise outcomes and complicate toxicity management.

Timing of Initiation

• Radiation therapy should begin within one month postoperatively (based on general CNS tumor guidelines) 1
• Complete the concurrent vincristine during the 6-week radiation period before transitioning to maintenance 1

Average-Risk Criteria

Average-risk classification requires meeting ALL of the following: 1, 2

• M0 disease (no metastatic dissemination)
• Classic histology (not large cell/anaplastic)
• Gross total resection (GTR) or near-total resection (NTR)

Radiation Considerations

**Radiation is not recommended for patients <3 years of age**, though radiation-avoiding strategies may be considered for patients >3 years at the treating physician's discretion. 1, 2 This guideline applies specifically to radiation-inclusive treatment strategies.

Common Pitfalls to Avoid

• Do not use low-dose CSI (<23.4 Gy) - studies demonstrated that low-dose CSI is less efficient than standard-dose CSI for average-risk disease 1
• Do not delay radiation therapy - maintain the treatment timeline to optimize outcomes 1
• Do not switch between protocols mid-treatment - the COG and St. Jude maintenance regimens differ significantly and are not interchangeable 1