The role of radiotherapy in adult medulloblastoma: long-term single-institution experience and a review of the literature

Brain diffusion MRI biomarkers after oncology treatments

In addition to providing a measurement of the tumor's size and dimensions, magnetic resonance imaging (MRI) provides excellent noninvasive radiographic detection of tumor location. The MRI technique is an important modality that has been shown to be useful in the prognosis, diagnosis, treatment planning, and evaluation of response and recurrence in solid cancers. Diffusion-weighted imaging (DWI) is an imaging technique that quantifies water mobility. This imaging approach is good for identifying sub-voxel microstructure of tissues, correlates with tumor cellularity, and has been proven to be valuable in the early assessment of cytotoxic treatment for a variety of malignancies. Diffusion tensor imaging (DTI) is an MRI method that assesses the preferred amount of water transport inside tissues. This enables precise measurements of water diffusion, which changes according to the direction of white matter fibers, their density, and myelination. This measurement corresponds to some related variables: fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD), and others. DTI biomarkers can detect subtle changes in white matter microstructure and integrity following radiation therapy (RT) or chemoradiotherapy, which may have implications for cognitive function and quality of life. In our study, these indices were evaluated after brain chemoradiotherapy.

Management and Long-term Outcomes of Adults With Medulloblastoma: A Single-Center Experience

BACKGROUND AND OBJECTIVES

Medulloblastomas are embryonal tumors predominantly affecting children. Recognition of molecularly defined subgroups has advanced management. Factors influencing the management and prognosis of adult patients with medulloblastoma remains poorly understood.

METHODS

We examined the management, prognostic factors, and, when possible, molecular subgroup differences (subset) in adult patients (aged 18 years or older) with medulloblastoma from our center (specialty Neuro-Oncology clinic within a large academic practice) diagnosed between 1992 and 2020. Molecular subtyping corresponding to the 2021 WHO Classification was performed. Kaplan-Meier estimates (with log-rank test) were performed for univariate survival analysis with Cox regression used for multivariate analyses.

RESULTS

We included 76 adult patients with medulloblastoma (62% male), with a median age of 32 years at diagnosis (range: 18-66) and median follow-up of 7.7 years (range: 0.6-27). A subset of 58 patients had molecular subgroup characterization-37 SHH-activated, 12 non-WNT/non-SHH, and 9 WNT-activated. Approximately 67% underwent gross total resection, 75% received chemotherapy at diagnosis, and 97% received craniospinal irradiation with boost. The median overall survival (OS) for the whole cohort was 14.8 years. The 2-, 5-, and 10-year OS rates were 93% (95% CI 88-99), 86% (78-94), and 64% (53-78), respectively. Survival was longer for younger patients (aged 30 years or older: 9.9 years; younger than 30 years: estimated >15.4 years; log-rank p < 0.001). There was no survival difference by molecular subgroup or extent of resection. Only age at diagnosis remained significant in multivariate survival analyses.

DISCUSSION

We report one of the largest retrospective cohorts in adult patients with medulloblastoma with molecular subtyping. Survival and molecular subgroup frequencies were similar to prior reports. Survival was better for adult patients younger than 30 years at diagnosis and was not significantly different by molecular subgroup or management characteristics (extent of resection, RT characteristics, or chemotherapy timing or regimen).

Medulloblastoma of the adult: results from a multicenter retrospective study by AINO (Italian Association of Neuro-Oncology) and SIN (Italian Society of Neurology)

INTRODUCTION

Medulloblastoma (MB) is the most common primary malignant intracranial tumor in childhood, but it is very rare in adults, and for this reason, the optimal treatment has not yet been defined. We designed a multicentric study in order to define relevant outcome measures for future prospective studies.

MATERIALS AND METHODS

The project involved 10 Italian centers. The database shared among the centers contains epidemiological, diagnostic (radiological and histological/molecular), therapeutic, recurrence information, and survival data.

RESULTS

A total of 152 patients (102 males and 50 females, median age 32) were included in the study. Twenty-three of 152 patients had a diagnosis of classic medulloblastoma, 52/152 had desmoplastic/extensive nodularity, 2/152 had large-cell anaplastic medulloblastoma, and the remaining had diagnoses not otherwise specified. Almost all patients underwent craniospinal irradiation after surgery; in 85.5% of patients, adjuvant chemotherapy, mainly platinum- and etoposide-based chemotherapy, was performed immediately after RT. Upon recurrence, most patients were retreated with various chemotherapy regimens, including intrathecal chemotherapy in patients with leptomeningeal dissemination. The overall survival (OS) rate at 5 years was 73.3% (95% CI, 65.0-80.0%). The median OS for the whole group of patients was 112 months.

CONCLUSIONS

The data collected were mainly consistent with the literature. A limitation of this study was the large number of patients lost to follow-up and the lack of molecular data for most patients diagnosed until 2010. An important challenge for the future will be MB biologic characterization in adults, with the identification of specific genetic patterns. It will be important to have more national and international collaborations to provide evidence-based management strategies that attempt to obtain a standard of care.

Salvage Re-irradiation Options in Adult Medulloblastoma: A Case Report and Review of the Literature

BACKGROUND/AIM

Medulloblastoma is a rare tumor of adult age, while it occurs more frequently in children. Given the rarity, there is a lack of evidence for the treatment of recurrent disease. Few data are available about salvage re-irradiation collecting very heterogeneous series.

CASE REPORT

A 51-year-old male presented with headache, nausea, double vision, and gait disorders. A contrast-enhanced brain-MRI showed the presence of multifocal medulloblastoma. After surgery, adjuvant craniospinal radiotherapy was performed, chemotherapy was stopped due to toxicity. After 27 months, a new MRI and a Methionine-PET revealed a late pontocerebellar relapse; multidisciplinary board decided for a SBRT treatment. The second course of RT was well tolerated and 14 months later, the patient is alive in good general conditions, with no evidence of disease.

CONCLUSION

Our experience supports the use of salvage stereotactic radiotherapy as a safe and effective treatment option.

Radiotherapy for adult medulloblastoma: Long term result from a single institution. A review of prognostic factors and why we do need a multi-institutional cooperative program

AIM

We retrospectively analyzed our Institution experience with these patients. The endpoints of the analysis were overall survival (OS), disease-free survival (DFS), local control (LC), metastasis free survival (MFS); results were compared with the literature.

BACKGROUND

Medulloblastoma in adult patients is a very rare disease; the 5 and 10-year overall survival rates range between 33-78% and 27-56%, respectively. The collection of more clinical data is strongly needed.

MATERIALS AND METHODS

From September 1975 to October 2006, we treated 16 adult patients (9 males and 7 females) with a histological diagnosis of medulloblastoma. Acute and late toxicities were scored according to RTOG toxicity scale. Karnofski performance status (KPS) and neurological performance status (NPS) pre- and post-RT were reported. Median age was 27 years (range 18-53 years). All the patients received cranio-spinal irradiation, two patients were also given chemotherapy. Median follow-up period was 121.5 months.

RESULTS

In January 2014, 10/16 patients were alive without evidence of disease, 6/16 died with progressive disease (1 local and spinal, 3 spinal and 2 extraneural). Ten-year LC, OS, DFS, MFS were, respectively, 84%, 67%, 60% and 59%. Univariate analysis shows that gross total resection is associated with better survival. No acute or late G3-G4 toxicity was observed.

CONCLUSIONS

This experience and the analysis of the literature confirm the efficacy of postoperative RT but also the need of large datasets to better define prognostic factors and the possible role of the association of chemotherapy.

Technique, outcomes, and acute toxicities in adults treated with proton beam craniospinal irradiation

BACKGROUND

Proton craniospinal irradiation (p-CSI) has been proposed to reduce side effects associated with CSI. We evaluated acute toxicities and preliminary clinical outcomes in a series of adults treated with p-CSI.

METHODS

We reviewed medical records for 50 patients (aged 16-63 y) with malignancies of varying histologies treated consecutively with vertebral body-sparing p-CSI at MD Anderson Cancer Center from 2007 to 2011. Median CSI and total boost doses were 30.6 and 54 Gy. Forty patients received chemotherapy, varying by histology. Median follow-up was 20.1 months (range, 0.3-59).

RESULTS

Median doses to the thyroid gland, pituitary gland, hypothalamus, and cochleae were 0.003 Gy-relative biological effectiveness (RBE; range, 0.001-8.5), 36.1 Gy-RBE (22.5-53.0), 37.1 Gy-RBE (22.3-54.4), and 33.9 Gy-RBE (22.2-52.4), respectively. Median percent weight loss during CSI was 1.6% (range, 10% weight loss to 14% weight gain). Mild nausea/vomiting was common (grade 1 = 46%, grade 2 = 20%); however, only 5 patients experienced grade ≥2 anorexia (weight loss >5% baseline weight). Median percent baseline white blood cells, hemoglobin, and platelets at nadir were 52% (range, 13%-100%), 97% (65%-112%), and 61% (10%-270%), respectively. Four patients developed grade ≥3 cytopenias. Overall and progression-free survival rates were 96% and 82%, respectively, at 2 years and 84% and 68% at 5 years.

CONCLUSIONS

This large series of patients treated with p-CSI confirms low rates of acute toxicity, consistent with dosimetric models. Vertebral body-sparing p-CSI is feasible and should be considered as a way to reduce acute gastrointestinal and hematologic toxicity in adults requiring CSI.

Management of recurrent medulloblastoma in adult patients: a systematic review and recommendations

Medulloblastoma accounts for almost one-third of pediatric central nervous system (CNS) cancers, but is very rare in the adult population. As a result, adult patients with medulloblastoma are often treated according to therapies developed for children with similarly staged disease at diagnosis, based on the assumption that adult and pediatric tumors have similar properties. The purpose of this review was to summarize the evidence and to make recommendations for the management of recurrent disease in adult patients with medulloblastoma. We conducted a systematic literature search to find publications addressing treatment of recurrent medulloblastoma in adults. Current treatment strategies for adult patients with relapsed medulloblastoma are based on the results of retrospective case series and published consensus recommendations, and include maximal safe re-resection where possible, combined with chemotherapy and/or re-irradiation. We describe the results of 13 publications involving 66 adult patients treated with high-dose chemotherapy (HDCT) plus stem cell transplantation for recurrent medulloblastoma. HDCT with stem cell transplantation may be a treatment option for a small proportion of adult patients who are unlikely to benefit from conventional chemotherapy and who are fit and have their disease recurrence contained within the CNS. Potential cases in which stem cell transplantation is being considered should be discussed at a multidisciplinary tumor board which includes involvement by hematologic oncologists and transplant specialists.