Second primary brain tumors following cranial irradiation for pediatric solid brain tumors

Radiation-induced meningiomas (RIM) in adults: A single-centre retrospective experience

Introduction

Radiotherapy of central nervous system (CNS) is treatment against many paediatric cancers, even if it is a well-recognized risk factor for meningioma formation. An increased risk of developing secondary brain tumors like radiation-induced meningiomas (RIM) is related to irradiated patients.

Research question

This retrospective study aims to present RIM cases treated in a single tertiary-hospital in Greece and compare the results with international literature and cases of sporadic meningiomas.

Materials and methods

A single-centre retrospective study of all patients diagnosed between January 2012 and September 2022 with RIM after having been irradiated in CNS for paediatric cancer was undertaken through hospital's electronic record and clinical notes, identifying baseline demographics and latency period.

Results

Thirteen patients were identified with RIM diagnosis after receiving irradiation for Acute Lymphoblastic Leukaemia (69.2%), Premature Neuro-Ectodermal Tumour (23.1%), and Astrocytoma (7.7%). Median age at irradiation was 5 years old and 32 years old at RIM's presentation. The latent period from irradiation to meningioma diagnosis was 26.23 ​± ​5.96 years. After surgical excision, histopathologic results showed grade I meningiomas in 12 out of thirteen cases, while only one atypical meningioma was diagnosed.

Conclusion

Patients who underwent CNS-radiotherapy in childhood for any condition have an increased risk of developing secondary brain tumors such as radiation-induced meningiomas. RIMs resemble sporadic meningiomas in symptomatology, location, treatment, and histologic grade. However, long-term follow-up and regular check-ups are recommended in irradiated patients due to short latency period from irradiation to RIM development, which means younger age patients than those with sporadic meningiomas cases.

Re-irradiation of Pediatric Medulloblastoma: A Case Report and Systematic Review

Despite the optimal treatment given to children with medulloblastoma, many relapses are seen after combining treatments. Re-irradiation is part of salvage therapy for children who relapse and might provide long-term disease control. Nevertheless, it is challenging because there is a concern about exceeding radiation tolerances and late treatment toxicities. Re-irradiation is an option for many brain tumors, including medulloblastoma in children. This study presents a case of recurrent medulloblastoma treated with re-irradiation. A systematic review of the literature provided up-to-date data on the re-irradiation of medulloblastoma in children. This study aims to contribute to the scarce literature on the treatment strategy, which may help improve patients' outcomes.

Risk of secondary malignant neoplasms in children following proton therapy vs. photon therapy for primary CNS tumors: A systematic review and meta-analysis

Background

Central nervous system tumors are now the most common primary neoplasms seen in children, and radiation therapy is a key component in management. Secondary malignant neoplasms (SMNs) are rare, but dreaded complications. Proton beam therapy (PBT) can potentially minimize the risk of SMNs compared to conventional photon radiation therapy (RT), and multiple recent studies with mature data have reported the risk of SMNs after PBT. We performed this systematic review and meta-analysis to characterize and compare the incidence of SMNs after proton and photon-based radiation for pediatric CNS tumors.

Methods

A systematic search of literature on electronic (PubMed, Cochrane Central, and Embase) databases was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. We included studies reporting the incidence and nature of SMNs in pediatric patients with primary CNS tumors. The crude incidence of SMNs and all secondary neoplasms were separately extracted, and the random-effects model was used for pooled analysis and subgroup comparison was performed between studies using photons vs. protons.

Results

Twenty-four studies were included for analysis. A total of 418 SMNs were seen in 38,163 patients. The most common SMN were gliomas (40.6%) followed by meningiomas (38.7%), sarcomas (4.8%), and thyroid cancers (4.2%). The median follow-up was 8.8 years [3.3–23.2].The median latency to SMN for photons and protons were 11.9 years [5-23] and 5.9 years [5-6.7], respectively. The pooled incidence of SMNs was 1.8% (95% CI: 1.1%–2.6%, I² = 94%) with photons and 1.5% (95% CI: 0%–4.5%, I² = 81%) with protons. The pooled incidence of all SNs was not different [photons: 3.6% (95% CI: 2.5%–4.8%, I² = 96%) vs. protons: 1.5% (95% CI: 0–4.5%, I² = 80%); p = 0.21].

Conclusion

We observed similar rates of SMN with PBT at 1.5% compared to 1.8% with photon-based RT for pediatric CNS tumors. We observed a shorter latency to SMN with PBT compared to RT. With increasing use of pencil beam scanning PBT and VMAT, further studies are warranted to evaluate the risk of secondary cancers in patients treated with these newer modalities.

Glioblastoma Following Treated Medulloblastoma After 29 Years in the Posterior Fossa: Case Report and Review of Literature

Glioblastoma multiforme (GBM) is a high-grade glioma that may be a rare complication of radiotherapy. We report a case of a patient who was treated for medulloblastoma (MB) of the posterior fossa at the age of 27 years. Twenty-nine years later, at the age of 56 years, he presented with a double-location tumor: supratentorial and in the posterior fossa. Imaging features of the supratentorial location were very suggestive of a meningioma. We operated on the posterior fossa location, which revealed a glioblastoma. Histologically, the tumor cells exhibited characteristics of both GBM and rhabdoid tumor cells. Literature reports of cases of GBM following MB at the same place are very rare, and presenting rhabdoid characteristics is even rarer. This is the first case of MB and GBM at ages 27 and 56 years, respectively. The double-location supratentorial probable meningioma and GBM of the posterior fossa 32 years after MB is the only case reported in the literature. What to do in this case remains a topic of debate, and there are no clear recommendations in the literature.

Risk of secondary neoplasms after external-beam radiation therapy treatment of pediatric low-grade gliomas: a SEER analysis, 1973-2015

OBJECTIVE

Although past studies have associated external-beam radiation therapy (EBRT) with higher incidences of secondary neoplasms (SNs), its effect on SN development from pediatric low-grade gliomas (LGGs), defined as WHO grade I and II gliomas of astrocytic or oligodendrocytic origin, is not well understood. Utilizing a national cancer registry, the authors sought to characterize the risk of SN development after EBRT treatment of pediatric LGG.

METHODS

A total of 1245 pediatric patient (aged 0-17 years) records from 1973 to 2015 were assembled from the Surveillance, Epidemiology, and End Results (SEER) database. Univariable and multivariable subdistribution hazard regression models were used to evaluate the prognostic impact of demographic, tumor, and treatment-related covariates. Propensity score matching was used to balance baseline characteristics. Cumulative incidence analyses measured the time to, and rate of, SN development, stratified by receipt of EBRT and controlled for competing mortality risk. The Fine and Gray semiparametric model was used to estimate future SN risk in EBRT- and non-EBRT-treated pediatric patients.

RESULTS

In this study, 366 patients received EBRT and 879 did not. Forty-six patients developed SNs after an LGG diagnosis, and 27 of these patients received EBRT (OR 3.61, 95% CI 1.90-6.95; p < 0.001). For patients alive 30 years from the initial LGG diagnosis, the absolute risk of SN development in the EBRT-treated cohort was 12.61% (95% CI 8.31-13.00) compared with 4.99% (95% CI 4.38-12.23) in the non-EBRT-treated cohort (p = 0.013). Cumulative incidence curves that were adjusted for competing events still demonstrated higher rates of SN development in the EBRT-treated patients with LGGs. After matching across available covariates and again adjusting for the competing risk of mortality, a clear association between EBRT and SN development remained (subhazard ratio 2.26, 95% CI 1.21-4.20; p = 0.010).

CONCLUSIONS

Radiation therapy was associated with an increased risk of future SNs for pediatric patients surviving LGGs. These data suggest that the long-term implications of EBRT should be considered when making treatment decisions for this patient population.

Optimization of Intracranial Germinoma Treatment: Radiotherapy Alone with Reduced Volume and Dose

PURPOSE

We investigated optimal management for intracranial germinoma, including target volume and dose of radiation therapy (RT) and the combination of RT and chemotherapy (CTx).

METHODS AND MATERIALS

We retrospectively evaluated 213 patients with intracranial germinoma treated between 1971 and 2017. Treatment policies changed as diagnostic techniques and clinical experience improved. In the 1980s, trial RT and tumor marker study were performed, and craniospinal irradiation was performed to treat patients with presumed germinoma. CTx was introduced in 1991, and RT volume was reduced in patients showing a complete response. In 2012, the policy was changed to a "reduced volume/dose RT alone" approach, involving a smaller target volume (the whole ventricle/whole brain for localized disease) without CTx. RT doses were gradually reduced to 36 Gy for primary tumors and 18 Gy for neuraxis.

RESULTS

The median age was 16 years. In total, 118 and 95 patients had pathologically proven and presumed germinoma, respectively, and 151 and 62 patients had localized and multifocal or metastatic diseases, respectively. With a median follow-up of 141 months, the 10-year disease-free and overall survival rates were 91.6% and 95.6%, respectively. Recurrence rates were similar for patients receiving RT-only (9 of 137, 6.6%) and those receiving CTx + RT (4 of 73, 5.5%); all patients receiving CTx-only experienced recurrences (3 of 3, 100%). Rates were the highest in the focal RT group (10 of 29, 34.5%) but were relatively low in the whole ventricle/whole brain RT (3 of 51, 5.9%) and craniospinal irradiation groups (0 of 130, 0%). Infield failure occurred in 3 patients. Fourteen patients died of recurrence (n = 4), secondary malignancy (n = 4), CTx-related toxicity (n = 2), and others (n = 4). Among the 33 patients who received "reduced volume/dose RT alone" treatment, 2 (6.1%) experienced recurrence in the spinal cord and biopsy tract, respectively.

CONCLUSIONS

The additional benefit of CTx in the treatment of intracranial germinoma seems minimal. An RT-only approach with reduced target volume and dose seems reasonable.

Secondary glioblastoma after treatment of intracranial germinoma - would radiation-only therapy still be safe? Case report

BACK GROUND

Intracranial germinomas are one of the most radiosensitive tumors and are curable by radiotherapy (RT) alone. RT-only therapy without chemotherapy is effective. But, as patients with germinoma can expect long-term survival, the adverse effects of RT and late sequelae in survivors are of most concern. So, recently, standard treatment protocol of combination with chemotherapy and reduced dose of RT could be widely acceptable.

CASE PRESENTATION

We report a patient with germinoma who developed RT-induced glioblastoma. He was diagnosed as biopsy-proven germinoma at the age of 12. Postoperatively, he underwent RT alone without chemotherapy and remained free of tumor without recurrence during long-term follow up. However, after almost 20 year, he developed RT-induced glioblastoma.

CONCLUSIONS

Although RT has the highest priority among treatments on intracranial germinomas, RT-only therapy with full dose for germinoma can have delayed severe complications. So, chemotherapy prior to reduced dose RT is more desirable.

Radiation-induced glioblastoma with rhabdoid characteristics following treatment for medulloblastoma: A case report and review of the literature

Glioblastoma multiforme (GBM) is a high-grade glioma that may develop from several other central nervous system tumors after radiation therapy. We herein report a case of GBM occurring 8 years after radiation therapy for medulloblastoma. The secondary tumor was histologically distinctly different from the primary tumor. Previously reported cases indicate that GBM induced by radiation therapy is associated with a highly aggressive clinical course with a high risk of early recurrence and poor prognosis. In addition, histological examination revealed that the tumor cells exhibited characteristics of both GBM and rhabdoid tumor cells. The diverse pathological characteristics of GBM may reflect the potential effects of radiation therapy on the tumor.

Medulloblastoma therapy generates risk of a poorly-prognostic H3 wild-type subgroup of diffuse intrinsic pontine glioma: a report from the International DIPG Registry

With improved survivorship in medulloblastoma, there has been an increasing incidence of late complications. To date, no studies have specifically addressed the risk of radiation-associated diffuse intrinsic pontine glioma (DIPG) in medulloblastoma survivors. Query of the International DIPG Registry identified six cases of DIPG with a history of medulloblastoma treated with radiotherapy. All patients underwent central radiologic review that confirmed a diagnosis of DIPG. Six additional cases were identified in reports from recent cooperative group medulloblastoma trials (total n = 12; ages 7 to 21 years). From these cases, molecular subgrouping of primary medulloblastomas with available tissue (n = 5) revealed only non-WNT, non-SHH subgroups (group 3 or 4). The estimated cumulative incidence of DIPG after post-treatment medulloblastoma ranged from 0.3-3.9%. Posterior fossa radiation exposure (including brainstem) was greater than 53.0 Gy in all cases with available details. Tumor/germline exome sequencing of three radiation-associated DIPGs revealed an H3 wild-type status and mutational signature distinct from primary DIPG with evidence of radiation-induced DNA damage. Mutations identified in the radiation-associated DIPGs had significant molecular overlap with recurrent drivers of adult glioblastoma (e.g. NRAS, EGFR, and PTEN), as opposed to epigenetic dysregulation in H3-driven primary DIPGs. Patients with radiation-associated DIPG had a significantly worse median overall survival (median 8 months; range 4-17 months) compared to patients with primary DIPG. Here, it is demonstrated that DIPG occurs as a not infrequent complication of radiation therapy in survivors of pediatric medulloblastoma and that radiation-associated DIPGs may present as a poorly-prognostic distinct molecular subgroup of H3 wild-type DIPG. Given the abysmal survival of these cases, these findings provide a compelling argument for efforts to reduce exposure of the brainstem in the treatment of medulloblastoma. Additionally, patients with radiation-associated DIPG may benefit from future therapies targeted to the molecular features of adult glioblastoma rather than primary DIPG.

Malignant Gliomas as Second Neoplasms in Pediatric Cancer Survivors: Neuropathological Study

This study presents a unique series of malignant supratentorial gliomas in children previously cured from non-CNS primary cancer. On neuroimaging these tumors were not specific, so the patients were suspected of cerebral recurrence of their primary neoplasm: leukemia in four children and sarcoma in one child. Histologically, the group contained four glioblastomas and one anaplastic astrocytoma. Three patients underwent neurosurgical resection, while the other two underwent stereotactic diagnostic biopsy only. Despite combined oncological treatment, four children died during 20 months, and only one glioblastoma patient continued to live for another twelve years. Microscopically, the neoplasms consisted of small cells with some morphologic features of astrocytic lineage, having scanty or prominent processes. Microvascular proliferation and focal or diffuse necrosis were encountered in four cases. The GFAP reactivity in neoplastic cells was low or nil, together with the expression of Olig2, vimentin, and nestin. In two cases a subpopulation of synaptophysin-positive cells was present. Molecular immunohistochemical profiling revealed the expression of phosphorylated forms of PI3Kp110 and AKT, in parallel to a strong PTEN and p53 positivity. The tumors were of IDH1R132H-wild type and immunoreactive for ATRX, HER3, and EGFR. Secondary malignant gliomas in pediatric cancer survivors pose a diagnostic challenge. The present study shows that these tumors are of IDH wild type, PI3K/AKT-activated, having no PTEN and EGFR mutations. Therefore, the biopsy of brain tumors in such patients is crucial both for accurate diagnosis and material preservation for molecular typing.

Radiation-Induced Meningiomas: An Exhaustive Review of the Literature

OBJECTIVE

Radiation-induced meningioma (RIM) is an uncommon late risk of cranial irradiation. We conducted an exhaustive review of individual patient data to characterize RIM.

METHODS

Using a systematic search of the PubMed database, we performed a comprehensive literature review to characterize and investigate RIM. Student t tests were used to evaluate differences between variables. A Kaplan-Meier analysis was used to assess survival. Statistical significance was assessed using a log-rank test.

RESULTS

Our analysis included 251 cases of RIM. The average age at onset for the primary lesion was 13.0 ± 13.5 years, and the average radiation dose delivered to this lesion was 38.8 ± 16.8 Gy. Secondary meningiomas could be divided into grades I (140), II (55), and III (10) tumors. Thirty patients (11.9%) had multiple lesions, and 46 (18.3%) had recurrent meningiomas. The latency period between radiotherapy for primary lesions and the onset of meningiomas was 22.9 ± 11.4 years. The latency period was shorter for patients with grade III meningioma and for those in the high-dose and intermediate-dose radiation groups who received systemic chemotherapy. Aggressive meningiomas and multiple meningiomas were more common in the high-dose and intermediate-dose groups than in the low-dose group. The 5-year and 10-year survival rates for all patients with meningioma were 77.7% and 66.1%, respectively.

CONCLUSIONS

For patients treated with cranial radiotherapy, the risk of secondary meningioma warrants a longer follow-up period beyond the standard time frame typically designated for determining the risk of primary tumor relapse.

A successful case of an anaplastic meningioma treated with chemotherapy for soft tissue sarcomas

Malignant meningioma has a bad prognosis. Surgery and radiotherapy are the most effective therapeutic options, without an established role for chemotherapy. We report a case of 2-year-old male child with diagnosis of postoperative relapse of a malignant meningioma. Considering the rapid progression, the young age and the lack of effective therapeutic alternatives, the patient underwent multidisciplinary anticancer treatment with a protocol made for soft tissue sarcomas (EpSSG NRSSTS 2005 protocol), with positive outcome. This case represents a successful management of an anaplastic meningioma with a multimodal treatment, including chemotherapy, in a pediatric patient.

Antioxidative enzymes in irradiated rat brain-indicators of different regional radiosensitivity

PURPOSE

Previously, we examined manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (CuZnSOD), and catalase (CAT) activities in rat brain irradiated with 2 or 3 Gy of γ-rays. The results indicated that lower MnSOD activity and inducibility found in hippocampus might explain higher radiosensitivity of this brain region. Thus, in this study, we wanted to determine changes of MnSOD, CuZnSOD, and CAT activities after dose of 5 Gy and to find out if differences in MnSOD activity are caused by changes in its expression.

METHODS

Heads of 4-day-old female rats were irradiated with γ-rays, using (60)Co. Animals were sacrificed 1/24 h after exposure. Hippocampus and cortex tissues were prepared for enzyme activity measurements and Western blot analysis.

RESULTS

One hour after exposure, γ-rays significantly decreased MnSOD activity in both examined brain regions. Twenty-four hours later, MnSOD recovery showed dose and regional dependence. It was weaker at higher doses and in hippocampal region. MnSOD expression changed in the similar manner as MnSOD activity only at lower doses of γ-rays. In both examined brain regions, gamma radiation significantly decreased CuZnSOD activity and did not change activity of CAT.

CONCLUSIONS

Our results confirmed that MnSOD plays an important role in different regional radiosensitivity but also showed that depending on dose, radiation affects MnSOD level by utterly different mechanisms. Postradiation changes of CuZnSOD and CAT are not regionally specific and therefore, cannot account for the different radiosensitivity of the hippocampus and cortex.

Anaplastic ganglioglioma: a report of three cases and review of the literature

Gangliogliomas are rare tumors of the central nervous system that are thought to arise from a glioneuronal precursor and consist of both neuronal and glial elements. Grade III, or anaplastic ganglioglioma (AGG), most commonly affects children and young adults, generally arises in a supratentorial location, is highly epileptogenic, and often results in diffuse local and distant failure within the craniospinal axis. Pathologically, these tumors are graded by the degree of malignancy in their glial portion and radiologic diagnosis is difficult due to the wide variation in its degree of solid and cystic components, contrast uptake, and calcification patterns. This report presents three cases of AGG, with initial treatment including subtotal resection followed by conformal radiotherapy. In the case where the AGG developed in the setting of an existent low-grade astrocytoma, the patient received no chemotherapy. Both of the other de novo cases were managed with adjuvant chemoradiotherapy with temozolomide. Recurrence occurred at 6, 16, and 20 months following therapy. Two of the three patients experienced symptomatic decline at recurrence, but experienced Karnofsky performance status (KPS) improvement after salvage therapy, including the reduction of cranial neuropathy and balance. All patients had a significant reduction in presenting symptoms following salvage therapy. Patients died at 23, 20, and 22 months following initial surgical management, respectively. A review of anaplastic and malignant gangliogliomas is presented in the context of these three cases.

Second brain tumors following central nervous system radiotherapy in childhood

OBJECTIVE

The second tumour (ST) occurrence is a relatively uncommon late complication of radiotherapy but represents one of the most significant issues, especially in childhood oncology. We describe our experience with patients who developed second brain neoplasm following cranial irradiation in childhood.

METHODS

We identified nine patients who received radiotherapy owing to central nervous system tumour in childhood and subsequently developed the second brain tumour. The full clinical and radiological documentation and histopathological reports were reviewed. Risk factors such as age at irradiation, latency period to ST diagnosis, radiotherapy doses and volumes and other therapy methods were evaluated. We correlated the ST location with the three levels of irradiation dose (high, >40 Gy; medium, 25-40 Gy; and low <25 Gy).

RESULTS

Five meningiomas and four gliomas occurred as the ST after the mean time of 11.7 years after radiotherapy. The average age of children during irradiation was 4.6 years. The shorter latency time to the ST induction was found in children treated with chemotherapy (9 years vs 17.2 years). Seven STs developed in the area of high and moderate dose (>25 Gy), only two low-grade gliomas appeared in the low-dose region.

CONCLUSION

Our data suggest that the STs usually develop in the brain tissues that received doses >25 Gy in patients irradiated at a young age.

ADVANCES IN KNOWLEDGE

The low-dose volume seems not to be so significant for second brain neoplasm induction. Therefore, the modern intensity-modulated radiotherapy technique could be safely applied in paediatric patients.