Craniospinal irradiation for medulloblastoma treatment
This comprehensive radiation approach is used because medulloblastoma has the potential to spread throughout the brain and spinal cord through cerebrospinal fluid pathways.
Here's a brief overview of craniospinal irradiation for medulloblastoma treatment:
Indication: CSI is typically recommended for patients with medulloblastoma, especially those at high risk of metastasis or with evidence of cancer cells in the cerebrospinal fluid. It is often part of the standard treatment regimen for this type of brain tumor.
Purpose: The primary goal of CSI is to eradicate cancer cells throughout the central nervous system to reduce the risk of recurrence and metastasis. It is used in conjunction with other treatments, such as surgery and chemotherapy.
Radiation Delivery: CSI involves the use of high-energy X-rays or photons. The radiation is carefully targeted to the entire brain and spinal cord. Specialized equipment and techniques are used to shape the radiation beams and minimize exposure to healthy tissues.
Treatment Planning: Before CSI is initiated, detailed treatment planning is performed. This includes CT or MRI scans to precisely define the target area for radiation and to spare normal tissues from excessive radiation exposure.
Fractionation: CSI is usually administered in multiple sessions or fractions over several weeks. The total radiation dose is divided into smaller, daily treatments to minimize side effects on healthy tissues and organs.
Side Effects: Like all radiation therapies, CSI can cause side effects. Common side effects may include fatigue, hair loss, skin irritation, and changes in cognitive function, especially in pediatric patients. These side effects are closely monitored and managed by the healthcare team.
Follow-Up: After completing CSI, patients will undergo regular follow-up appointments to assess treatment response and monitor for any potential recurrence or long-term side effects. Additional treatments, such as chemotherapy, may be recommended based on individual cases.
Prognosis: The prognosis for medulloblastoma varies depending on various factors, including the patient's age, tumor stage, and molecular subtype. CSI, when used as part of a multimodal treatment approach, has improved the prognosis for many patients with medulloblastoma.
Risk-Benefit Evaluation: The decision to use CSI is carefully considered, weighing the potential benefits in terms of tumor control against the risk of side effects, especially in pediatric patients. The healthcare team discusses the treatment plan and its implications with the patient and their family.
In summary, craniospinal irradiation is a vital component of the treatment strategy for medulloblastoma, aiming to eliminate cancer cells throughout the central nervous system. It is designed to improve the chances of disease control and reduce the risk of recurrence in patients with this aggressive brain tumor. The treatment plan is individualized based on the patient's specific condition and risk factors, and it is an essential part of the multidisciplinary approach to managing medulloblastoma.
One of the most significant challenges in patients with medulloblastoma is reducing the dose of craniospinal irradiation (CSI) to minimize neurological sequelae in survivors. Molecular characterization of patients receiving lower than standard doses of CSI therapy is important to facilitate further reduction of treatment burden 1)
Surgical resection followed by craniospinal irradiation (CSI) has been the mainstay of medulloblastoma treatment for many years 2).
The standard radiation regimen has comprised a dose of 36 Gy to the entire craniospinal axis followed by a boost to the whole posterior fossa, for a total dose of 55 Gy 3) 4).
Thanks to cisplatin-based chemotherapy added to the therapy regimen for medulloblastoma, the survival for the high-risk diseases has been improved 5) and the radiation dose of neuraxis for the average-risk disease has been decreased without compromising survival.
The interval between surgery and radiation is a significant prognostic factor for disease-free survival. 6).
Modern radiotherapy techniques are able to avoid side effects in a fragile patient population. However, high-risk patients remain with relevant mortality and many patients still suffer from treatment related toxicity 7).
Current clinical trials are evaluating risk-adapted radiotherapy in standard-risk medulloblastoma to reduce long-term sequelae, whereas the research approach in high-risk medulloblastoma is to improve clinical outcomes with dose-intensification of chemotherapy and the use of hyperfractionated radiotherapy regimens. Technological advances, such as tomotherapy, volumetric modulated arc therapy, and proton therapy, may further improve the therapeutic ratio by reducing radiotherapy toxicities. A selected group of children with recurrent disease after treatment for standard-risk medulloblastoma may be considered for re-irradiation 8).
Loss of H3K27 trimethylation promotes radiotherapy resistance in medulloblastoma and induces an actionable vulnerability to BET inhibition 9).
Histology, molecular subgroup, GTR, and radiotherapy are significantly associated with survival parameters in patients with medulloblastoma. Nevertheless, high-quality prospective cohort studies are necessary to improve the conclusions 10)
Radiomics signature
Radiomics signature and nomogram performed well for the prediction of PFS and could stratify patients underwent postoperative radiotherapy into the high- and low-risk groups with significantly different clinical outcomes 11).