Outcomes of Local Radiation and Intensified Combined Intrathecal Methotrexate and High-dose Chemotherapy for Intracranial Germ Cell Tumors

The role of neoadjuvant chemotherapy in the management of metastatic central nervous system germinoma: A meta-analysis

BACKGROUND

The role of neoadjuvant chemotherapy in treating patients with metastatic central nervous system (CNS) germinoma is controversial.

METHODS

We compared the relapse-free survival (RFS) of different treatment modalities by performing a meta-analysis using published data. We summarized all data using standard descriptive statistics. We used the Kaplan-Meier method to estimate RFS and their corresponding 95% confidence intervals (CIs). We used the log-rank test for the comparison of survival functions.

RESULTS

We identified 97 patients with a median age at presentation of 15 years (range: 7-38). Sites of metastasis were cerebrospinal fluid (CSF) disease only (n = 12), brain parenchyma (n = 18), spinal cord (n = 9), ventricular and CSF (n = 10), ventricular only (n = 31), and other (n = 17). The 3-year RFS among patients who received any form of radiotherapy was 89% (95% CI: 83-96) compared with 0% for patients who received a chemotherapy-only regimen (p = .001). Five-year RFS among patients who received craniospinal irradiation (CSI) was 92% (95% CI: 84-100) compared with 76.4% (95% CI: 63-90) in the non-CSI group (with or without neoadjuvant chemotherapy) (p = .014). Five-year RFS of patients who received CSI less than 24 Gy with neoadjuvant chemotherapy was 100% compared with 92% (95% CI: 83-100) CSI dose greater than or equal to 24 Gy alone (p = .3).

CONCLUSIONS

Our analysis does not support avoiding spinal irradiation among patients with radiographic metastatic CNS germinoma. Future studies are needed to confirm whether neoadjuvant chemotherapy will allow a reduction of irradiation dose without compromising survival.

Proton therapy for pediatric diencephalic tumors

Diencephalic tumors tend to be low grade tumors located near several critical structures, including the optic nerves, optic chiasm, pituitary, hypothalamus, Circle of Willis, and hippocampi. In children, damage to these structures can impact physical and cognitive development over time. Thus, the goal of radiotherapy is to maximize long term survival while minimizing late effects, including endocrine disruption leading to precocious puberty, height loss, hypogonadotropic hypogonadism, and primary amenorrhea; visual disruption including blindness; and vascular damage resulting in cerebral vasculopathy. Compared to photon therapy, proton therapy offers the potential to decrease unnecessary dose to these critical structures while maintaining adequate dose to the tumor. In this article, we review the acute and chronic toxicities associated with radiation for pediatric diencephalic tumors, focusing on the use of proton therapy to minimize treatment-related morbidity. Emerging strategies to further reduce radiation dose to critical structures will also be considered.

The comparison of acute toxicities associated with craniospinal irradiation between photon beam therapy and proton beam therapy in children with brain tumors

Introduction

This study aimed to evaluate acute toxicities associated with irradiation between the X‐CSI (photon beam craniospinal irradiation) and P‐CSI (proton beam craniospinal irradiation) groups in children with brain tumors.

Methods

Sixty‐two consecutive patients who received initial craniospinal irradiation (CSI) for brain tumors in our center between January 1, 2011 and May 31, 2021, were included in the study. Acute toxicities were retrospectively evaluated during CSI using Common Terminology Criteria for Adverse Events version 5.0. Maximum grades of fatigue, headache, insomnia, nausea, vomiting, dermatitis, constipation, abdominal pain, oropharyngeal mucositis, and hematological toxicities were evaluated.

Results

Thirty‐six patients received X‐CSI, and 26 patients received P‐CSI. The median dose of CSI was 18.0 Gy in the X‐CSI group and 23.4 Gy (relative biological effectiveness) in the P‐CSI group (p < 0.001). The P‐CSI group had a lower incidence of more than grade 2 nausea (11.5% vs. 69.4%, p = 0.008) and vomiting (7.7% vs. 38.8%, p < 0.001), compared with the X‐CSI group. Multivariate logistic regression analysis with adjustments for potential confounding factors of doses of CSI showed that proton radiation therapy was associated with a marked reduced risk of more than grade 2 nausea and vomiting during CSI (adjusted odds ratio, 0.050; 95% confidential interval, 0.011–0.24; p < 0.001).

Conclusion

The present study suggests that P‐CSI reduces the acute gastrointestinal toxicities associated with irradiation.