Is the Chemotherapy Plan for Medulloblastoma Related to Age? Do All Patients Need Radiotherapy After Chemotherapy?

Is the Chemotherapy Plan for Medulloblastoma Related to Age? Do All Patients Need Radiotherapy After Chemotherapy?

Source: Sunflower Children  

Author: Sunflower Children  

Editor: Gao ZX  

Date: 2023-10-08  

The "Frequently Asked Questions About Medulloblastoma" column invites experts in the field of pediatric brain tumors to answer various questions regarding medulloblastoma. Today, we bring you the fourth issue, and we welcome you to leave your questions in the comments section!

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Disclaimer:  

The online Q&A on popular science is not a recommendation for treatment plans. Due to the inability to understand patients' detailed conditions and to conduct face-to-face diagnoses, expert opinions are for reference only. For specific treatment plans, please visit a reputable hospital.

1. Is the chemotherapy plan for medulloblastoma related to age?

The choice of treatment plan for medulloblastoma is related to age, with 3-4 years serving as the dividing line for different chemotherapy regimens. For children younger than 3-4 years, especially those with the desmoplastic/nodular subtype or extensive nodular subtype, and molecular classification as SHH with PTCH1 mutations, high-dose chemotherapy is primarily used to avoid radiotherapy. For classic or large cell/anaplastic types, children classified as G3/G4 may initially receive high-dose chemotherapy, with radiotherapy being administered after they reach 3-4 years of age.

2. Do all children with medulloblastoma need radiotherapy after chemotherapy?

Medulloblastoma is a tumor that is highly sensitive to radiation, making radiotherapy an important supplementary treatment method. For patients aged 3 years and older, radiotherapy should be the first choice unless there are special circumstances (e.g., silent disease or non-cooperation with radiotherapy). For disseminated cases, it is recommended to first use chemotherapy to reduce tumor burden before proceeding with radiotherapy, although the treatment sequence remains a topic of debate among scholars. For patients under 3 years of age, radiotherapy can significantly damage developing brain tissue, affecting long-term cognitive function and height; thus, high-dose chemotherapy should be prioritized. For those older than 3 years who can tolerate radiotherapy, classic or large cell/anaplastic types, as well as G3/G4 molecular classification, must undergo radiotherapy.

3. How should the treatment effects be monitored during chemotherapy?

The evaluation of treatment effects is based on pediatric brain tumor efficacy analysis standards, primarily involving regular re-examinations with MRI of the entire brain and spine, along with monitoring for tumor cells in the cerebrospinal fluid. Children with high-risk factors should be assessed after every two cycles of chemotherapy, while those without high-risk factors generally undergo evaluation every three months.

4. Is the interval for chemotherapy drugs calculated from the first day of medication or from the end?

The interval for chemotherapy drugs is calculated based on the first day of administration. However, in clinical practice, if the expected chemotherapy duration has been reached but blood counts are inadequate, or if there is an infection or other factors affecting chemotherapy, a delay may be considered.

5. How often should follow-up examinations occur after medulloblastoma treatment, and what should be checked?

After treatment, follow-up examinations generally involve MRI scans of the head and spine with contrast. Children who have undergone radiotherapy need to have their endocrine markers checked. Generally, MRIs are performed every three months for the first one to two years following treatment, every six months from the third to fifth years, and annually thereafter. Endocrine markers are usually checked once a year; if abnormalities are found, the frequency of follow-ups should be increased. After five years, annual follow-ups are sufficient.

Follow-up timing can also be calculated based on the surgical date. Within two years post-surgery (within one year after chemotherapy ends), examinations should occur every three months, with every six months from the third to fifth years. Endocrine markers should generally be checked annually, with increased frequency if any abnormalities arise. After five years, annual follow-ups are adequate.  

Formatting: Ying Tao  

Proofreading: Chen Zhenyu