Promising survival rate but high incidence of treatment-related mortality after reduced-dose craniospinal radiotherapy and tandem high-dose chemotherapy in patients with high-risk medulloblastoma

Multiparametric MRI-Based Radiomics Signature with Machine Learning for Preoperative Prediction of Prognosis Stratification in Pediatric Medulloblastoma

RATIONALE AND OBJECTIVES

Despite advances in risk-stratified treatment strategies for children with medulloblastoma (MB), the prognosis for MB with short-term recurrence is extremely poor, and there is still a lack of evaluation of short-term recurrence risk or short-term survival. This study aimed to construct and validate a radiomics model for predicting the outcome of MB based on preoperative multiparametric magnetic resonance images (MRIs) and to provide an objective for clinical decision-making.

MATERIALS AND METHODS

The clinical and imaging data of 64 patients with MB admitted to Shenzhen Children's Hospital from December 2012 to December 2021 and confirmed by pathology were retrospectively collected. According to the 18-month progression-free survival, the cases were classified into a good prognosis group and a poor prognosis group, and all cases were divided into training group (70%) and validation group (30%) randomly. Radiomics features were extracted from MRI of each child. The consistency test, t-test, and the least absolute shrinkage and selection operator were used for feature selection. The support vector machine (SVM) and receiver operator characteristic were used to evaluate the distinguishing ability of the selected features to the prognostic groups. RAD score was calculated based on the selected features. The clinical characteristics and RAD score were included in the multivariate logistic regression, and prediction models were constructed by screening out independent influences. The radiomics nomogram was constructed, and its clinical significance was evaluated.

RESULTS

A total of 1930 radiomic features were extracted from the images of each patient, and 11 features were included in the construction of radiomics score after selected. The area under the curve (AUC) values of the SVM model in the training and validation groups were 0.946 and 0.797, respectively. The radiomics nomogram was constructed based on the training cohort, and the AUC values in the training group and the validation group were 0.926 and 0.835, respectively. The results of clinical decision curve analysis showed that a good net benefit could be obtained from the nomogram.

CONCLUSION

The radiomics nomogram established based on MRI can be used as a noninvasive predictive tool to evaluate the prognosis of children with MB, which is expected to help neurosurgeons better conduct preoperative planning and patient follow-up management.

Long-term Outcomes of Protocol-Based Treatment for Newly Diagnosed Medulloblastoma

PURPOSE

The Korean Society of Pediatric Neuro-Oncology (KSPNO) conducted treatment strategies for children with medulloblastoma (MB) by using alkylating agents for maintenance chemotherapy or tandem high-dose chemotherapy (HDC) with autologous stem cell rescue (ASCR) according to the risk stratification. The purpose of the study was to assess treatment outcomes and complications based on risk-adapted treatment and HDC.

MATERIALS AND METHODS

Fifty-nine patients diagnosed with MB were enrolled in this study. Patients in the standard-risk (SR) group received radiotherapy (RT) after surgery and chemotherapy using the KSPNO M051 regimen. Patients in the high-risk (HR) group received two and four chemotherapy cycles according to the KSPNO S081 protocol before and after reduced RT for age following surgery and two cycles of tandem HDC with ASCR consolidation treatment.

RESULTS

In the SR group, 24 patients showed 5-year event-free survival (EFS) and overall survival (OS) estimates of 86.7% (95% confidence interval [CI], 73.6 to 100) and 95.8% (95% CI, 88.2 to 100), respectively. In the HR group, more infectious complications and mortality occurred during the second HDC than during the first. In the HR group, the 5-year EFS and OS estimates were 65.5% (95% CI, 51.4 to 83.4) and 72.3% (95% CI, 58.4 to 89.6), respectively.

CONCLUSION

High intensity of alkylating agents for SR resulted in similar outcomes but with a high incidence of hematologic toxicity. Tandem HDC with ASCR for HR induced favorable EFS and OS estimates compared to those reported previously. However, infectious complications and treatment-related mortalities suggest that a reduced chemotherapy dose is necessary, especially for the second HDC.

Hypothalamic-pituitary-gonadal function, pubertal development, and fertility outcomes in male and female medulloblastoma survivors: a single-center experience

BACKGROUND

Endocrine deficiencies, including hypothalamic-pituitary-gonadal axis (HPGA) impairment, are common in survivors of childhood and adolescent medulloblastoma. Still, data regarding pubertal development and fecundity are limited, and few studies assessed HPGA function in males. We aimed to describe HPGA function in a large cohort of patients with medulloblastoma.

METHODS

A retrospective study comprising all 62 medulloblastoma patients treated in our center between 1987 and 2021, who were at least 2 years from completion of therapy. HPGA function was assessed based on clinical data, biochemical markers, and questionnaires.

RESULTS

Overall, 76% of female patients had clinical or biochemical evidence of HPGA dysfunction. Biochemical evidence of diminished ovarian reserve was seen in all prepubertal girls (n = 4). Among the males, 34% had clinical or biochemical evidence of gonadal dysfunction, 34% had normal function, and 29% were age-appropriately clinically and biochemically prepubertal. The difference between males and females was significant (P = .003). Cyclophosphamide-equivalent dose was significantly associated with HPGA function in females, but not in males. There was no association between HPGA dysfunction and other endocrine deficiencies, length of follow-up, weight status, and radiation treatment protocol. Two female and 2 male patients achieved successful pregnancies, resulting in 6 live births.

CONCLUSIONS

HPGA dysfunction is common after treatment for childhood medulloblastoma. This is seen more in females, likely due to damage to the ovaries from spinal radiotherapy. Our findings may assist in counseling patients and their families regarding risk to future fertility and need for fertility preservation.

Questions and answers in the management of children with medulloblastoma over the time. How did we get here? A systematic review

Introduction

Treatment of children with medulloblastoma (MB) includes surgery, radiation therapy (RT) and chemotherapy (CT). Several treatment protocols and clinical trials have been developed over the time to maximize survival and minimize side effects.

Methods

We performed a systematic literature search in May 2023 using PubMed. We selected all clinical trials articles and multicenter studies focusing on MB. We excluded studies focusing exclusively on infants, adults, supratentorial PNETs or refractory/relapsed tumors, studies involving different tumors or different types of PNETs without differentiating survival, studies including <10 cases of MB, solely retrospective studies and those without reference to outcome and/or side effects after a defined treatment.

Results

1. The main poor-prognosis factors are: metastatic disease, anaplasia, MYC amplification, age younger than 36 months and some molecular subgroups. The postoperative residual tumor size is controversial.2. MB is a collection of diseases.3. MB is a curable disease at diagnosis, but survival is scarce upon relapse.4. Children should be treated by experienced neurosurgeons and in advanced centers.5. RT is an essential treatment for MB. It should be administered craniospinal, early and without interruptions.6. Craniospinal RT dose could be lowered in some low-risk patients, but these reductions should be done with caution to avoid relapses.7. Irradiation of the tumor area instead of the entire posterior fossa is safe enough.8. Hyperfractionated RT is not superior to conventional RT9. Both photon and proton RT are effective.10. CT increases survival, especially in high-risk patients.11. There are multiple drugs effective in MB. The combination of different drugs is appropriate management.12. CT should be administered after RT.13. The specific benefit of concomitant CT to RT is unknown.14. Intensified CT with stem cell rescue has no benefit compared to standard CT regimens.15. The efficacy of intraventricular/intrathecal CT is controversial.16. We should start to think about incorporating targeted therapies in front-line treatment.17. Survivors of MB still have significant side effects.

Conclusion

Survival rates of MB improved greatly from 1940-1970, but since then the improvement has been smaller. We should consider introducing targeted therapy as front-line therapy.

Targeting Angiogenic Factors for the Treatment of Medulloblastoma

OPINION STATEMENT

Medulloblastoma (MB) is the most frequent pediatric brain tumor. Despite conventional therapy, MB patients have high mortality and morbidity rates mainly due to the incomplete understanding of the molecular and cellular processes involved in development of this cancer. Similar to other solid tumors, MB demonstrated high endothelial cell proliferation and angiogenic activity, wherein new blood vessels arise from the pre-existing vasculature, a process named angiogenesis. MB angiogenesis is considered a hallmark for MB development, progression, and metastasis emphasizing its potential target for antitumor therapy. However, angiogenesis is tightly regulated by a set of angiogenic factors making it a complex process to be targeted. Although agents targeting these factors and their receptors are early in development, the potential for their targeting may translate into improvement in the clinical care for MB patients. In this review, we focus on the most potent angiogenic factors and their corresponding receptors, highlighting their basic properties and expression in MB. We describe their contribution to MB tumorigenesis and angiogenesis and the potential therapeutic targeting of these factors.

Risk Stratification of Childhood Medulloblastoma Using Integrated Diagnosis: Discrepancies with Clinical Risk Stratification

BACKGROUND

Recent genomic studies identified four discrete molecular subgroups of medulloblastoma (MB), and the risk stratification of childhood MB in the context of subgroups was refined in 2015. In this study, we investigated the effect of molecular subgroups on the risk stratification of childhood MB.

METHODS

The nCounter® system and a customized cancer panel were used for molecular subgrouping and risk stratification in archived tissues.

RESULTS

A total of 44 patients were included in this study. In clinical risk stratification, based on the presence of residual tumor/metastasis and histological findings, 24 and 20 patients were classified into the average-risk and high-risk groups, respectively. Molecular subgroups were successfully defined in 37 patients using limited gene expression analysis, and DNA panel sequencing additionally classified the molecular subgroups in three patients. Collectively, 40 patients were classified into molecular subgroups as follows: WNT (n = 7), SHH (n = 4), Group 3 (n = 8), and Group 4 (n = 21). Excluding the four patients whose molecular subgroups could not be determined, among the 17 average-risk group patients in clinical risk stratification, one patient in the SHH group with the TP53 variant was reclassified as very-high-risk using the new risk classification system. In addition, 5 out of 23 patients who were initially classified as high-risk group in clinical risk stratification were reclassified into the low- or standard-risk groups in the new risk classification system.

CONCLUSION

The new risk stratification incorporating integrated diagnosis showed some discrepancies with clinical risk stratification. Risk stratification based on precise molecular subgrouping is needed for the tailored treatment of MB patients.

Promising survival rate but high incidence of treatment-related mortality after reduced-dose craniospinal radiotherapy and tandem high-dose chemotherapy in patients with high-risk medulloblastoma

BACKGROUND

In this study, we report the follow-up results of reduced dose of craniospinal radiotherapy (CSRT) followed by tandem high-dose chemotherapy (HDCT) in patients with high-risk medulloblastoma (MB).

METHODS

Newly diagnosed high-risk MB patients (metastatic disease, postoperative residual tumor >1.5 cm² , or large cell/anaplastic histology) over 3 years of age were enrolled in this study. Two cycles of pre-RT chemotherapy, radiotherapy (RT) including reduced-dose CSRT (23.4 or 30.6 Gy), four cycles of post-RT chemotherapy, and tandem HDCT were administered. NanoString and DNA sequencing were performed using archival tissues.

RESULTS

In all, 40 patients were enrolled, and molecular subgrouping was possible in 21 patients (2 wingless, 3 sonic hedgehog, 8 Group 3, and 8 group 4). All patients including two patients who experienced progression during the induction chemotherapy underwent HDCT. Relapse/progression occurred only in four patients (5-year cumulative incidence [CI] 10.4 ± 0.3%). However, six patients died from treatment-related mortality (TRM) (four acute TRMs and two late TRMs) resulting in 18.5 ± 0.5% of 5-year CI. Taken together, the 5-year event-free survival and overall survival were 71.1 ± 8.0% and 73.2 ± 7.9%, respectively. Late effects were evaluated in 25 patients and high-tone hearing loss, endocrine dysfunction, dyslipidemia, and growth retardation were common.

CONCLUSIONS

The strategy using tandem HDCT following reduced-dose CSRT showed promising results in terms of low relapse/progression rate; however, the high TRM rate indicates that modification of HDCT regimen and careful selection of patients who can benefit from HDCT will be needed in the future study.