Radiation-induced malignant gliomas: is there a role for reirradiation?

Radiotherapy-induced glioblastoma: distinct differences in overall survival, tumor location, pMGMT methylation and primary tumor epidemiology in Hong Kong chinese patients

INTRODUCTION

Radiotherapy-induced glioblastomas (RIGB) are a well-known late and rare complication of brain irradiation. Yet the clinical, radiological and molecular characteristics of these tumors are not well characterized.

METHODS

This was a retrospective multicentre study that analysed adult patients with newly diagnosed glioblastoma over a 10-year period. Patients with RIGB were identified according to Cahan's criteria for radiation-induced tumors. A case-control analysis was performed to compare known prognostic factors for overall survival (OS) with an independent cohort of IDH-1 wildtype de novo glioblastomas treated with standard temozolomide chemoradiotherapy. Survival analysis was performed by Cox proportional hazards regression.

RESULTS

A total of 590 adult patients were diagnosed with glioblastoma. 19 patients (3%) had RIGB. The mean age of patients upon diagnosis was 48 years ± 15. The mean latency duration from radiotherapy to RIGB was 14 years ± 8. The mean total dose was 58Gy ± 10. One-third of patients (37%, 7/19) had nasopharyngeal cancer and a fifth (21%, 4/19) had primary intracranial germinoma. Compared to a cohort of 146 de novo glioblastoma patients, RIGB patients had a shorter median OS of 4.8 months versus 19.2 months (p-value: <.001). Over a third of RIGBs involved the cerebellum (37%, 7/19) and was higher than the control group (4%, 6/146; p-value: <.001). A fifth of RIGBs (21%, 3/19) were pMGMT methylated which was significantly fewer than the control group (49%, 71/146; p-value: .01). For RIGB patients (32%, 6/19) treated with re-irradiation, the one-year survival rate was 67% and only 8% for those without such treatment (p-value: .007).

CONCLUSION

The propensity for RIGBs to develop in the cerebellum and to be pMGMT unmethylated may contribute to their poorer prognosis. When possible re-irradiation may offer a survival benefit. Nasopharyngeal cancer and germinomas accounted for the majority of original malignancies reflecting their prevalence among Southern Chinese.

Case report: Radiographic complete response of radiation-induced glioblastoma to front-line radiotherapy: A report and molecular characterization of two unique cases

Radiation-induced gliomas (RIGs) are an uncommon disease type and a known long-term complication of prior central nervous system radiation exposure, often during childhood. Given the rarity of this malignancy subtype, no clinical trials have explored optimal therapy for these patients, and the literature is primarily limited to reports of patient cases and series. Indeed, the genomic profiles of RIGs have only recently been explored in limited numbers, categorizing these gliomas into a unique subset. Here, we describe two cases of RIG diagnosed as glioblastoma (GB), IDH-wildtype, in adults who had previously received central nervous system radiation for childhood cancers. Both patients demonstrated a surprising complete radiographic response of the postoperative residual disease to front-line therapy, a phenomenon rarely observed in the management of any GB and never previously reported for the radiation-induced subgroup. Both tumors were characterized by next-generation sequencing and chromosomal microarray to identify potential etiologies for this response as well as to further add to the limited literature about the unique molecular profile of RIGs, showing signatures more consistent with diffuse pediatric-type high-grade glioma, H3-wildtype, and IDH-wildtype, WHO grade 4. Ultimately, we demonstrate that treatment utilizing a radiation-based regimen for GB in a previously radiated tissue can be highly successful despite historical limitations in the management of this disease.

Exposure to radon and heavy particulate pollution and incidence of brain tumors

BACKGROUND

Global incidence for brain tumors varies substantially without explanation. Studies correlating radon exposure and incidence are inconclusive. Particulate pollution has been linked to increased tumor incidence. Particulates may disrupt the blood-brain barrier allowing intracranial exposure to oncogenic radon. We investigated the relationship between exposure to residential radon, particulate pollution, and brain tumor incidence in the United States (US).

METHODS

County-level median radon testing results and annual air quality index values were obtained and divided into tertiles. Counties without both values were excluded. Four groups of counties were generated: high particulate/high radon (high/high), high/low, low/high, and low/low. Using incidence data from the Central Brain Tumor Registry of the US (provided by CDC's National Program of Cancer Registries and NCI's SEER), annual age-adjusted incidence rates (AAAIRs) by group were generated by behavior. Incidence rate ratios were calculated to examine for significant differences (α = .05). Poisson regression accounting for possible confounders was conducted.

RESULTS

Counties with available data included 83% of the US population. High/high exposure was significantly associated with increased AAAIR of all non-malignant tumors (up to 26% higher, including most meningiomas) even after accounting for potential confounders. An increased AAAIR was noted for all malignant tumors (up to 10% higher), including glioblastoma, but was negated after accounting for demographic/socioeconomic differences.

CONCLUSIONS

We present the first report suggesting increased non-malignant brain tumor incidence in regions with high particulate and radon exposure. These findings provide insight into unexplained variation in tumor incidence. Future studies are needed to validate these findings in other populations.

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.

Surveillance of long-term complications after treatment of adult brain tumor survivors—review and evidence-based recommendations

AbstractAs a result of treatment and diagnosis, adults with primary or metastatic brain tumors experience comorbidities that impacts their health and well-being. The Children’s Oncology Group has guideline recommendations for childhood survivors of brain tumors; however, guidelines for monitoring long-term sequela among adult brain tumor survivors are lacking. The purpose of this review is to present the screening recommendations for the long-term complications after brain tumor treatment from a multidisciplinary panel of healthcare professionals. Chronic complications identified include cognitive dysfunction, vasculopathy, endocrinopathy, ophthalmic, ototoxicity, physical disability, sleep disturbance, mood disorder, unemployment, financial toxicity, and secondary malignancy. We invited specialists across disciplines to perform a literature search and provide expert recommendations for surveillance for long-term complications for adult brain tumor survivors. The Brain Tumor Center Survivorship Committee recommends routine screening using laboratory testing, subjective assessment of symptoms, and objective evaluations to appropriately monitor the complications of brain tumor treatments. Effective monitoring and treatment should involve collaboration with primary care providers and may require referral to other specialties and support services to provide patient-centered care during neuro-oncology survivorship. Further research is necessary to document the incidence and prevalence of medical complications as well as evaluate the efficacy of screening and neuro-oncology survivorship programs.

Assessment of therapeutic outcome and role of reirradiation in patients with radiation-induced glioma

Background

We sought to clarify the optimal follow-up, therapeutic strategy, especially the role of reirradiation, and the diagnostic impact of isocitrate dehydrogenase (IDH) 1 and 2 mutation status in patients with radiation-induced glioma (RIG).

Methods

We retrospectively reviewed the clinical characteristics and treatment outcomes of 11 patients with high-grade glioma who satisfied Cahan’s criteria for RIG in our database during 2001–2021. IDH 1/2 mutations were analyzed by Sanger sequencing and/or pyrosequencing.

Results

The RIGs included glioblastoma with IDH 1/2 wild-type (n = 7), glioblastoma not otherwise specified (n = 2), anaplastic astrocytoma with IDH1/2 wild-type (n = 1), and anaplastic astrocytoma not otherwise specified (n = 1). The median period from primary disease and RIG diagnosis was 17 years (range: 9–30 years). All patients underwent tumor removal or biopsy, 5 patients postoperatively received reirradiation combined with chemotherapy, and 6 patients were treated with chemotherapy alone. The median progression-free and survival times were 11.3 and 28.3 months. The median progression-free survival time of patients treated with reirradiation and chemotherapy (n = 5) tended to be longer than that of patients that received chemotherapy alone (n = 6) (17.0 vs 8.1 months). However, the median survival time was similar (29.6 vs 27.4 months). Local recurrence was observed in 5 patients treated with chemotherapy alone, whereas in 2 patients among 4 patients treated with reirradiation and chemotherapy. None of the patients developed radiation necrosis. In one case, the primary tumor was diffuse astrocytoma with IDH2 mutant, and the secondary tumor was glioblastoma with IDH 1/2 wild-type. Based on the difference of IDH2 mutation status, the secondary tumor with IDH 1/2 wild-type was diagnosed as a de novo tumor that was related to the previous radiation therapy.

Conclusions

RIG can occur beyond 20 years after successfully treating the primary disease using radiotherapy; thus, cancer survivors should be informed of the long-term risk of developing RIG and the need for timely neuroimaging evaluation. Reirradiation combined with chemotherapy appears to be feasible and has favorable outcomes. Determining the IDH1/2 mutational status is useful to establish RIG diagnosis when the primary tumor is glioma.

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.

Advanced Magnetic Resonance Imaging in Pediatric Glioblastomas

The shortly upcoming 5th edition of the World Health Organization Classification of Tumors of the Central Nervous System is bringing extensive changes in the terminology of diffuse high-grade gliomas (DHGGs). Previously "glioblastoma," as a descriptive entity, could have been applied to classify some tumors from the family of pediatric or adult DHGGs. However, now the term "glioblastoma" has been divested and is no longer applied to tumors in the family of pediatric types of DHGGs. As an entity, glioblastoma remains, however, in the family of adult types of diffuse gliomas under the insignia of "glioblastoma, IDH-wildtype." Of note, glioblastomas still can be detected in children when glioblastoma, IDH-wildtype is found in this population, despite being much more common in adults. Despite the separation from the family of pediatric types of DHGGs, what was previously labeled as "pediatric glioblastomas" still remains with novel labels and as new entities. As a result of advances in molecular biology, most of the previously called "pediatric glioblastomas" are now classified in one of the four family members of pediatric types of DHGGs. In this review, the term glioblastoma is still apocryphally employed mainly due to its historical relevance and the paucity of recent literature dealing with the recently described new entities. Therefore, "glioblastoma" is used here as an umbrella term in the attempt to encompass multiple entities such as astrocytoma, IDH-mutant (grade 4); glioblastoma, IDH-wildtype; diffuse hemispheric glioma, H3 G34-mutant; diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype; and high grade infant-type hemispheric glioma. Glioblastomas are highly aggressive neoplasms. They may arise anywhere in the developing central nervous system, including the spinal cord. Signs and symptoms are non-specific, typically of short duration, and usually derived from increased intracranial pressure or seizure. Localized symptoms may also occur. The standard of care of "pediatric glioblastomas" is not well-established, typically composed of surgery with maximal safe tumor resection. Subsequent chemoradiation is recommended if the patient is older than 3 years. If younger than 3 years, surgery is followed by chemotherapy. In general, "pediatric glioblastomas" also have a poor prognosis despite surgery and adjuvant therapy. Magnetic resonance imaging (MRI) is the imaging modality of choice for the evaluation of glioblastomas. In addition to the typical conventional MRI features, i.e., highly heterogeneous invasive masses with indistinct borders, mass effect on surrounding structures, and a variable degree of enhancement, the lesions may show restricted diffusion in the solid components, hemorrhage, and increased perfusion, reflecting increased vascularity and angiogenesis. In addition, magnetic resonance spectroscopy has proven helpful in pre- and postsurgical evaluation. Lastly, we will refer to new MRI techniques, which have already been applied in evaluating adult glioblastomas, with promising results, yet not widely utilized in children.

Defining the molecular features of radiation-induced glioma: A systematic review and meta-analysis

Background

Cranial radiation therapy is essential in treating many pediatric cancers, especially brain tumors; however, its use comes with the risk of developing second malignancies. Cranial radiation-induced gliomas (RIGs) are aggressive high-grade tumors with a dismal prognosis, for which no standard therapy exists. A definitive molecular signature for RIGs has not yet been established. We sought to address this gap by performing a systematic review and meta-analysis of the molecular features of cranial RIGs.

Methods

A systematic review of the literature was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles and case reports that described molecular analyses of cranial radiation-induced high-grade gliomas were identified and evaluated, and data extracted for collation.

Results

Of 1727 records identified, 31 were eligible, containing 102 unique RIGs with molecular data. The most frequent genetic alterations in RIGs included PDGFRA or TP53 mutations, PDGFRA or CDK4 amplifications, and CDKN2A deletion, along with 1q gain, 1p loss and 13q loss. Of note, mutations in ACVR1, EGFR, H3F3A, HIST1H3B, HIST1H3C, IDH2, SMARCB1 or the TERT promoter were not observed. A comparative analysis revealed that RIGs are molecularly distinct from most other astrocytomas and gliomas and instead align most closely with the pedGBM_RTK1 subgroup of pediatric glioblastoma.

Conclusions

This comprehensive analysis highlights the major molecular features of RIGs, demonstrates their molecular distinction from many other astrocytomas and gliomas, and reveals potential genetic drivers and therapeutic targets for this currently fatal disease.

A Review of Particle Therapy for Skull Base Tumors: Modern Considerations and Future Directions

Skull base tumors constitute one of the established indications for particle therapy, specifically proton therapy. However, a number of prognostic factors, practical clinical management issues, and the emerging role of carbon ion therapy remain subjects of active clinical investigation. This review summarizes these topics, assesses the present status, and reflects on future research directions focusing on the management of chordomas, one of the most aggressive skull base tumors. In addition, the role of particle therapy for benign tumors of the skull base, including pituitary adenoma and acoustic neuroma, is reviewed.

Radiation-induced spinal cord glioblastoma subsequent to treatment of medulloblastoma: case report

Medulloblastomas are one of the most common malignant pediatric brain tumors. Therapy has evolved into multimodality treatments consisting of surgery, radiation, and adjuvant chemotherapy. While craniospinal radiation remains standard for patients older than 3 years of age, it is not free of side effects and long-term complications. The development of malignant gliomas following therapy is a well-documented phenomenon. However, the majority of these radiation-induced glioblastomas (RIG) are intracranial, and intraspinal lesions are rare. The patient is a 22-year-old female with a history of a posterior fossa medulloblastoma diagnosed 8 years prior for which she underwent surgical resection followed by adjuvant chemotherapy and craniospinal radiation. Surveillance imaging showed no evidence of recurrence or new lesions for the following 5 years. She presented with nausea and vomiting and imaging revealing a new intramedullary cervical spinal cord lesion. She then developed acute quadriplegia several days after presentation. She underwent a cervical laminectomy and resection of this lesion, which was initially diagnosed as recurrent medulloblastoma before genomic analysis ultimately revealed it to be a RIG. Spinal RIGs that occur secondary to treatment for an intracranial neoplasm are exceedingly rare. The majority of spinal cord RIGs have been reported secondary to treatment for tumors outside of the neuroaxis, while the majority of RIGs secondary to treatment for intracranial tumors remain intracranial. Nevertheless, RIGs are associated with a short clinical history, aggressive progression, and poor outcome.

A Novel Orthotopic Patient-Derived Xenograft Model of Radiation-Induced Glioma Following Medulloblastoma

Radiation-induced glioma (RIG) is a highly aggressive brain cancer arising as a consequence of radiation therapy. We report a case of RIG that arose in the brain stem following treatment for paediatric medulloblastoma, and the development and characterisation of a matched orthotopic patient-derived xenograft (PDX) model (TK-RIG915). Patient and PDX tumours were analysed using DNA methylation profiling, whole genome sequencing (WGS) and RNA sequencing. While initially thought to be a diffuse intrinsic pontine glioma (DIPG) based on disease location, results from methylation profiling and WGS were not consistent with this diagnosis. Furthermore, clustering analyses based on RNA expression suggested the tumours were distinct from primary DIPG. Additional gene expression analysis demonstrated concordance with a published RIG expression profile. Multiple genetic alterations that enhance PI3K/AKT and Ras/Raf/MEK/ERK signalling were discovered in TK-RIG915 including an activating mutation in PIK3CA, upregulation of PDGFRA and AKT2, inactivating mutations in NF1, and a gain-of-function mutation in PTPN11. Additionally, deletion of CDKN2A/B, increased IDH1 expression, and decreased ARID1A expression were observed. Detection of phosphorylated S6, 4EBP1 and ERK via immunohistochemistry confirmed PI3K pathway and ERK activation. Here, we report one of the first PDX models for RIG, which recapitulates the patient disease and is molecularly distinct from primary brain stem glioma. Genetic interrogation of this model has enabled the identification of potential therapeutic vulnerabilities in this currently incurable disease.

Updates in Pediatric Malignant Gliomas

Malignant gliomas constitute a smaller portion of brain tumors in children compared with adults. Nevertheless, they can be devastating tumors with poor prognosis. Recent advances and improved understanding of the genetic and molecular characterization of pediatric brain tumors, including those of malignant gliomas, have led to the reclassification of many pediatric brain tumors and new entities have been defined. In this paper, we will present some of the more recent characterization and pertinent changes in pediatric high-grade gliomas, along with the conventional and advanced imaging features associated with these entities. Implications of the recent changes in pediatric malignant glioma classifications will also be discussed.

Secondary brain tumors after cranial radiation therapy: A single-institution study

Aim

To study the probability of developing secondary brain tumors after cranial radiotherapy.Background Patients treated with cranial radiotherapy are at risk for developing secondary brain tumors.

Patients and methods

We planned an institutional survey for secondary brain tumors in survivors after cranial irradiation and reviewed the 30-year duration data. Event analysis and cumulative proportion curves were performed to generally estimate the cumulative proportion of developing secondary brain tumors, cavernoma and meningioma at different periods of time.

Results

Secondary brain tumors occurred in 21% of cases: 10% were cavernomas, 6% were meningiomas, 3% were skull osteomas, and 1% were anaplastic astrocytoma. The cumulative proportion of developing secondary brain tumor was 6% at 10 years and 20% at 20 years, while the cumulative proportion for developing cavernomas and meningiomas was 16% and 7% at 20 years, respectively.

Conclusion

Our study shows that patients who received cranial irradiation were at risk of secondary brain tumors such as cavernomas and meningiomas. Thus, a meticulous follow-up of cancer survivors with history of cranial irradiation by an annual MRI scan is justifiable. This will help clinicians to detect secondary brain tumors early and make its management much easier.

Concurrent Pituicytoma, Meningioma, and Cavernomas After Cranial Irradiation for Childhood Acute Lymphoblastic Leukemia

BACKGROUND

The majority of patients with acute lymphoblastic leukaemia develop disease relapse in the central nervous system in the absence of central nervous system-directed prophylactic therapy. In the past, prophylactic cranial irradiation was commonly used in the form of whole-brain radiotherapy in patients with acute lymphoblastic leukemia to prevent the development of intracranial diseases. However, in addition to the inherent risk of toxicity, this type of therapy has several delayed side effects including the development of secondary intracranial tumors.

CASE DESCRIPTION

We report a rare case of a patient with concurrent pituicytoma, meningioma, and cavernomas 44 years after prophylactic cranial irradiation for childhood acute lymphoblastic leukemia. The patient presented with visual disturbance, headache, and features of hypopituitarism. Endoscopic transsphenoidal resection of the pituicytoma and meningioma was performed. Subsequent regrowth of the residual meningioma necessitated further surgery and adjuvant treatment with radiotherapy.

CONCLUSIONS

This case report highlights the unusual case of a patient with 3 concurrent intracranial lesions of distinct pathologies after prophylactic cranial irradiation therapy for childhood acute lymphoblastic leukemia.

Radiation-Induced DNA Damage Cooperates with Heterozygosity of TP53 and PTEN to Generate High-Grade Gliomas

Glioblastomas are lethal brain tumors that are treated with conventional radiation (X-rays and gamma rays) or particle radiation (protons and carbon ions). Paradoxically, radiation is also a risk factor for GBM development, raising the possibility that radiotherapy of brain tumors could promote tumor recurrence or trigger secondary gliomas. In this study, we determined whether tumor suppressor losses commonly displayed by patients with GBM confer susceptibility to radiation-induced glioma. Mice with Nestin-Cre-driven deletions of Trp53 and Pten alleles were intracranially irradiated with X-rays or charged particles of increasing atomic number and linear energy transfer (LET). Mice with loss of one allele each of Trp53 and Pten did not develop spontaneous gliomas, but were highly susceptible to radiation-induced gliomagenesis. Tumor development frequency after exposure to high-LET particle radiation was significantly higher compared with X-rays, in accordance with the irreparability of DNA double-strand breaks (DSB) induced by high-LET radiation. All resultant gliomas, regardless of radiation quality, presented histopathologic features of grade IV lesions and harbored populations of cancer stem-like cells with tumor-propagating properties. Furthermore, all tumors displayed concomitant loss of heterozygosity of Trp53 and Pten along with frequent amplification of the Met receptor tyrosine kinase, which conferred a stem cell phenotype to tumor cells. Our results demonstrate that radiation-induced DSBs cooperate with preexisting tumor suppressor losses to generate high-grade gliomas. Moreover, our mouse model can be used for studies on radiation-induced development of GBM and therapeutic strategies. SIGNIFICANCE: This study uncovers mechanisms by which ionizing radiation, especially particle radiation, promote GBM development or recurrence.

Disseminated High-grade Glioma in a Long-term Survivor of Medulloblastoma: Implications and Management of Radiation-induced Malignancies

We describe a gentleman diagnosed with a posterior fossa medulloblastoma in 1998, successfully treated with craniospinal radiation therapy (RT) and posterior fossa RT boost, followed by 12 months of adjuvant chemotherapy. Nineteen years later, at the age of 28, the patient presented with multiple cranial neuropathies and was found to have disseminated high-grade glioma with leptomeningeal dissemination. In addition to the salient features of this case, we provide a brief review of RT-induced malignancies and the need for further research regarding surveillance and prevention strategies.

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.

Hyperfractionated abdominal reirradiation for gastrointestinal malignancies

Background

We sought to determine the role of abdominal reirradiation for patients presenting with recurrent or new primary gastrointestinal (GI) malignancies. At our institution, we have established a hyperfractionated, accelerated reirradiation regimen consisting of 39 Gray (Gy) in 26 twice-daily fractions. Although this regimen is used frequently in the pelvis, we sought to determine its toxicity and efficacy for abdominal tumors.

Methods

Twenty-four patients who received abdominal reirradiation with a hyperfractionated, accelerated approach from 2000 to 2017 were identified. Overall survival (OS) and local progression-free survival (LPFS) were calculated using the Kaplan-Meier method. Several patient, tumor and treatment characteristics were evaluated on univariate analyses for association with OS and LPFS using a Cox proportional hazards model.

Results

Of the twenty-four patients identified, the majority (n = 11, 46%) had pancreatic adenocarcinoma as their primary disease but also included upper GI adenocarcinoma (n = 4), colon adenocarcinoma (n = 3), hepatobiliary cancers (n = 4) and other malignancies (n = 2). The majority of patients received 45–50.4Gy in 1.8Gy fractions as their initial abdominal radiation course. The median reirradiation dose was 39Gy in 26 twice-daily fractions with a minimum six hour interval. The median [interquartile range (IQR)] interval between the courses of radiotherapy was 28 [18.6–38.9] months. Only palliative reirradiation intent was associated with decreased OS. While colon adenocarcinoma primary was significantly associated with increased LPFS, the sample size was small (n = 3). The 1-yr rate of LPFS was 38%. The median [IQR] duration of freedom from local progression was 8 [3.8–19.2] months. The 1-year OS was 50% and the median (IQR) OS was 14 [6.3–19.6] months. Thirteen patients (54%) had acute side effects with one patient experiencing G3 nausea and one experiencing a G4 bleed; the remaining patients experienced G1-G2 symptoms.

Conclusion

Hyperfractionated, accelerated reirradiation to the abdomen was relatively well-tolerated but provided limited local control to recurrent or second primary abdominal malignancies. Reirradiation could play a role in treating these patients with palliative or curative intent, but alternative strategies for delivering increased biologically effective dose should be further explored.

A 58-Year-Old Woman with Left-Sided Weakness and a History of a Pediatric Brain Tumor: A Case Report

Background

An uncommon but well-established complication of cranial irradiation is secondary neoplasm. This case presentation documents a radiation-induced malignant glioma 55 years after being diagnosed with “cerebral sarcoma,” now defined as atypical meningioma. This not only represents the longest reported latency period for a patient initially receiving over 30 Gy, but also provides a valuable historical perspective of neuro-oncology.

Clinical Presentation

A 58-year-old female presenting with progressive left-sided upper and lower extremity weakness with a past medical history significant for “cerebral sarcoma” was diagnosed with glioblastoma multiforme. This patient had previously been treated with resection and adjuvant radiation therapy via a 280-kVP orthovoltage machine and received 3,390 rad to the posterior three-quarters of the skull for “cerebral sarcoma.”

Conclusion

A comprehensive investigation of the past medical history helped uncover a mysterious pediatric diagnosis, helped drive the management 5 decades later, and serves as a reminder that seemingly safe interventions may still cause harm.

Rapidly Fatal Radiation-induced Glioblastoma

Glioblastoma (GBM) typically occurs as a primary tumour (i.e., primary GBM) and predominantly affects elderly patients. The remaining ~10% occur as a result of malignant progression from lower grade astrocytic tumours (i.e., secondary GBM). Although there are no certain causative environmental agents, prior radiation exposure may play a role. We report on a patient who had been treated six years prior for a vestibular schwannoma with high-dose conventional radiotherapy and subsequently developed a rapidly fatal glioblastoma at the same location. The diagnosis was confirmed by routine histopathology as well as more advanced techniques, such as whole genome copy number analysis.

A case of medulloblastoma in adult patient affected by anaplastic oligoastrocytoma

Medulloblastomas and high-grade gliomas (HGG) are two distinct brain tumor, with different peculiarities in terms of age of onset, localizations and prognosis. The coexistence of the two neoplasms in the same adult patient is an extremely rare event. We present the case of a woman treated with radio-chemotherapy for an HGG, who developed a cerebellar medulloblastoma 7 years later. Considering the poor prognosis of these tumors, the lack of knowledge about the mechanisms of onset as well as effective therapies, it is necessary to determine the exact role of irradiation and the presence of any potential molecular genetic abnormalities in the developing of the two tumors.

A case of multiple radiation-induced gliomas 24 years after radiation therapy against pituitary adenoma

We treated a case in which multiple astrocytomas of varying grades developed in the irradiation field 24 years after radiation therapy. Differentiation from radiation necrosis based on presurgical diagnostic imaging was difficult; therefore, we feel it is essential to aggressively pursue histological diagnoses to select the optimal treatment method.

Survival in glioblastoma: a review on the impact of treatment modalities

Glioblastoma (GBM) is the most common and lethal tumor of the central nervous system. The natural history of treated GBM remains very poor with 5-year survival rates of 5 %. Survival has not significantly improved over the last decades. Currently, the best that can be offered is a modest 14-month overall median survival in patients undergoing maximum safe resection plus adjuvant chemoradiotherapy. Prognostic factors involved in survival include age, performance status, grade, specific markers (MGMT methylation, mutation of IDH1, IDH2 or TERT, 1p19q codeletion, overexpression of EGFR, etc.) and, likely, the extent of resection. Certain adjuncts to surgery, especially cortical mapping and 5-ALA fluorescence, favor higher rates of gross total resection with apparent positive impact on survival. Recurrent tumors can be offered re-intervention, participation in clinical trials, anti-angiogenic agent or local electric field therapy, without an evident impact on survival. Molecular-targeted therapies, immunotherapy and gene therapy are promising tools currently under research.

Radiation-induced anaplastic ependymoma mimicking a skull base meningioma: A case report

The present study describes the case of a 63-year-old woman presenting with headache, dizziness and vomiting due to a an ovoid mass in the left pre-bulbar cistern, apparently arising from the lower clivus and the foramen magnum. The clinical history revealed the subtotal removal of a right cerebellar low-grade glioma 15 years previously and subsequent conventional 60-Gy radiotherapy. Notably, following gross total resection, histopathological examination showed microscopic features that resulted in a diagnosis of anaplastic ependymoma. The patient underwent surgery to remove the mass and post-operative chemotherapy with temozolomide. A progressive improvement of neurological signs and symptoms was observed during the postoperative course. At the 6-month follow-up, the patient was free from clinical and radiological recurrence. The unusual features of this rare secondary brain tumor were the extrassial location in the posterior fossa, the unusual age-associated location of the histological subtype and the fact that it closely mimicked a skull-base meningioma.

Fractionated stereotactic radiotherapy plus bevacizumab after response to bevacizumab plus irinotecan as a rescue treatment for high-grade gliomas

AIM

To evaluate the possibility of implementing a new scheme of rescue treatment after relapse or progression of high-grade glioma (HGG) treated at the first-line with bevacizumab and irinotecan (BVZ+CPT11), evaluating the response and toxicity of associating BVZ and fractionated stereotactic radiotherapy (BVZ+FSRT).

MATERIALS AND METHODS

We retrospectively analysed data from 59 patients with relapse of HGG. Nine patients with HGG relapse after treatment using the Stupp protocol that were treated with BVZ+CPT11 for progression between July 2007 and August 2012, after which the response was assessed according to the Revised Assessment in Neuro-Oncology (RANO) criteria. BVZ was administered at a dose of 10 mg/kg and FSRT up to a prescribed dose of 30 Gy, 500 cGy per fraction, three days a week. The median follow-up was 38 months.

RESULTS

The treatment was well-tolerated by all patients. The response after nuclear magnetic resonance imaging (MRI) at 3-6 months was progression in two patients, stable disease in four, and three patients had a partial response. The median overall survival (OS) from diagnosis until death or the last control was 36.8 months. The median progression-free survival (PFS) was 10.8 months. The results from tumour sub-group analysis indicated that the PFS was not statistically significant although it seemed that it was higher in grade-III. The OS was higher in grade-III gliomas.

CONCLUSIONS

The combination of BVZ+FSRT as a second-line HGG relapse rescue treatment is well-tolerated and seems to offer promising results. We believe that multi-centre prospective studies are needed to determine the long-term efficacy and toxicity of this therapeutic approach.

DNA double-strand breaks cooperate with loss of Ink4 and Arf tumor suppressors to generate glioblastomas with frequent Met amplification

Glioblastomas (GBM) are highly radioresistant and lethal brain tumors. Ionizing radiation (IR)-induced DNA double-strand breaks (DSBs) are a risk factor for the development of GBM. In this study, we systematically examined the contribution of IR-induced DSBs to GBM development using transgenic mouse models harboring brain-targeted deletions of key tumor suppressors frequently lost in GBM, namely Ink4a, Ink4b, Arf and/or PTEN. Using low linear energy transfer (LET) X-rays to generate simple breaks or high LET HZE particles (Fe ions) to generate complex breaks, we found that DSBs induce high-grade gliomas in these mice which, otherwise, do not develop gliomas spontaneously. Loss of Ink4a and Arf was sufficient to trigger IR-induced glioma development but additional loss of Ink4b significantly increased tumor incidence. We analyzed IR-induced tumors for copy number alterations to identify oncogenic changes that were generated and selected for as a consequence of stochastic DSB events. We found Met amplification to be the most significant oncogenic event in these radiation-induced gliomas. Importantly, Met activation resulted in the expression of Sox2, a GBM cancer stem cell marker, and was obligatory for tumor formation. In sum, these results indicate that radiation-induced DSBs cooperate with loss of Ink4 and Arf tumor suppressors to generate high-grade gliomas that are commonly driven by Met amplification and activation.

Clinical characteristics and pathogenesis of cerebellar glioblastoma

Cerebellar glioblastomas (GBMs) are rare, with neither their pathogenesis nor prognosis being completely understood. The present study aimed to clarify the clinical characteristics of cerebellar GBMs by comparison with supratentorial GBMs, focusing particularly on the pathogenesis. The clinical factors between cerebellar (n=10) and supratentorial (n=216) GBMs were compared. Additionally, p53 and epidermal growth factor receptor (EGFR) levels were investigated in six patients by immunostaining as well as the isocitrate dehydrogenase 1 (IDH1) status of five patients by direct sequencing. Eight males and two females participated in the present study, the mean age at diagnosis was 56.6 years and the range 37-75 years. Four patients presented with hydrocephalus and one with brainstem involvement, and two patients were diagnosed with neurofibromatosis type 1. Two patients had previously received radiotherapy, eight patients received postoperative radiotherapy and seven chemotherapy. The mean Karnofsky performance status (KPS) score was lower in patients with cerebellar GBMs compared to those with supratentorial GBM; however, the survival times did not differ between the two groups. All of the cases of six cerebellar GBMs were p53‑positive and EGFR‑negative, as detected by immunostaining, consistent with secondary GBM. However, no IDH1 mutations were detected in any of the five cases of cerebellar GBMs analyzed, indicating that these tumors were not of the secondary type. The KPS score with cerebellar GBMs may be lower due to hydrocephalus, which was ameliorated by surgery but may have impacted the survival rate. It was confirmed that cerebellar GBMs were identical to supratentorial GBMs with respect to its clinical features, with the possible exception of the KPS score. The present study's genetic analyses indicated that cerebellar GBMs may develop via a pathway different from that of either primary or secondary GBM.

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

PURPOSE

We describe our institution's experience with seven patients who developed second brain tumors following cranial irradiation.

METHODS

The median age at first irradiation was 8 years (range, 3-20 years). Initial diagnoses were two cases of germinoma, one non-germinomatous germ cell tumor (NGGCT), three cases of medulloblastoma, and one pineal gland tumor (pathology undetermined). All patients received craniospinal irradiation followed by local boost and the median dose to the initial tumor area was 54.0 Gy (range, 49.8-60.6 Gy). Four patients (two medulloblastomas, one germinoma, and one NGGCT) received chemotherapy.

RESULTS

Second brain tumors were diagnosed a median of 114 months (range, 64-203) after initial radiation. Pathologic diagnoses were one glioblastoma, two cases of anaplastic astrocytoma, one medulloblastoma, one low-grade glioma, one high-grade glial tumor, and one atypical meningioma. Five patients underwent surgical resection with subsequent radiotherapy. One anaplastic astrocytoma patient received chemotherapy only following stereotactic biopsy. The meningioma patient was alive 32 months after total resection and radiosurgery for subsequent recurrences. Six patients died within 18 months and most deaths were due to disease progression.

CONCLUSIONS

Most patients diagnosed with second brain tumors had received high-dose, large-volume radiotherapy with chemotherapy at a young age. Further studies are required to determine the relationship between radiotherapy/chemotherapy and the development of secondary brain tumors.

Secondary glioblastoma multiforme in a child with disseminated juvenile pilocytic astrocytoma

Secondary glioblastoma multiforme (sGBM) can occur after a long latency period following radiation treatment of various diseases including brain tumors, leukemia, and more benign disorders like tinea capitis. Outcomes of radiation-induced sGBM remain poor in both children and adults. We report a case of a 16-year-old girl with a history of disseminated juvenile pilocytic astrocytoma treated with chemotherapy and craniospinal radiation 9 years prior who developed sGBM in the absence of a tumor predisposition syndrome. She presented with a several-week history of headaches and no acute findings on computed tomography compared to baseline neuroimaging 3 months prior. Repeat computed tomography performed just 3 weeks later for worsening headaches revealed a new large posterior fossa tumor where pathology confirmed the diagnosis of sGBM. In spite of maximal surgical resection, reirradiation, and adjuvant chemotherapy, she died 1 year postdiagnosis. Our case highlights the potential late effects of high-dose cranial radiation, how symptomatology may precede neuroimaging findings, and the rapid formation of sGBM that mirrors that of de novo Glioblastoma Multiforme.

Anaplastic gliomas: radiation, chemotherapy, or both?

The optimal treatment of anaplastic gliomas is controversial. Options for treatment include radiation, chemotherapy or a combination of modalities. This article describes how treatment algorithms for anaplastic gliomas have evolved and interprets the results of recent studies. The available evidence indicates that patients can be treated with either chemotherapy or radiation as initial therapy, with use of the other treatment modality at relapse. Whether subpopulations exist for whom one treatment modality is superior to the other at initial diagnosis must be studied prospectively.

Salvage craniospinal irradiation with an intensity modulated radiotherapy technique for patients with disseminated neuraxis disease

PURPOSE

To report the use and results of a novel intensity modulated radiotherapy (IMRT)-based technique used for salvage craniospinal irradiation (CSI) in 6 patients who developed neuraxis disease after initial high-dose conformal radiotherapy (RT) to the brain.

METHODS AND MATERIALS

After Institutional Review Board approval, all patients treated for disseminated leptomeningeal disease with salvage CSI using IMRT with conventional external beam radiotherapy were identified. The medical records and radiotherapy dosimetry were reviewed. Tolerance, morbidity, tumor control, and overall survival were evaluated.

RESULTS

Six patients who received IMRT-based salvage CSI were identified. The median age was 6.5 years (range 2- 34 years) at initial RT and 7.7 years (range, 3-35 years) at salvage CSI. Disease progression necessitating salvage CSI was noted at a median of 10 months (range, 1-26 months) from the initial RT. The original disease site remained well controlled in all 6 patients. The median dose of the initial RT treatment was 52 Gy (range, 30.6-60 Gy). Salvage CSI dose was 36 Gy in 20 fractions in all 6 patients. IMRT was used to treat the cranial contents excluding the previously treated area. Five pediatric patients received electron beams to spine and 1 adult patient received photon beams to spine. IMRT allowed a conformal and uniform dose distribution to the target tissue while excluding previously treated areas. Salvage CSI dose of 36 Gy, delivered using IMRT and 36 Gy using electrons or photons to the spine, proved effective in providing good control of the disease.

CONCLUSIONS

This technique of salvage CSI was effective in this patient cohort for leptomeningeal dissemination occurring outside of an area of focal irradiation. The technique was well tolerated and thus far has not been associated with any significant toxicity. Salvage therapy has been effective in 4 of the 6 patients thus far.

Glioblastoma occurring at the site of a previous medulloblastoma following a 5-year remission period

We describe a case of a 14-year-old boy who developed a cerebellar and brainstem glioblastoma 5 years after treatment for a medulloblastoma. The patient first presented in 2003 with 9 months of vomiting and a 9-kg weight loss. A head MRI showed a heterogeneously enhancing posterior fossa mass with hydrocephalus. Gross total resection was performed and the tumor was consistent with a classic medulloblastoma. Postoperative chemotherapy and craniospinal radiation was administered. The patient remained tumor-free until 2008, at which time he presented with right-sided weakness and numbness, left eye pain, vomiting and weight loss. Imaging showed abnormalities within the posterior pons, medulla, inferior cerebellar peduncles, cerebellar hemispheres and cervicomedullary junction with expansion of the medulla and cervical spinal cord. Due to the location of the lesion, biopsy was felt to be too risky and was avoided. Despite receiving chemotherapy, his symptoms continued to worsen and he died 4 months later. Post mortem examination limited to the brain and spinal cord confirmed the radiographic extent of the tumor. Microscopic examination showed a highly cellular infiltrative glial neoplasm with extensive palisading necrosis. A diagnosis of glioblastoma was rendered. The question of whether the first and second tumors were related is of potential clinical and academic interest. The first tumor was synaptophysin-positive and GFAP-negative, consistent with medulloblastoma. The second tumor was synaptophysin-negative and focally GFAP-positive, consistent with glioblastoma. The glioblastoma displayed EGF receptor amplification, and interestingly, it also displayed MYCN amplification; both tumors showed low level PTEN deletion. The medulloblastoma displayed a signal pattern consistent with an isochromosome 17q, while the glioblastoma showed some cells with an isochromosome 17q signal pattern amid a background of cells with abundant chromosomal instability. The relationship between these two tumors, particularly with regard to various molecular events, is discussed.

Radiation-induced glioblastoma multiforme in children treated for medulloblastoma with characteristics of both medulloblastoma and glioblastoma multiforme

Outcomes for average-risk medulloblastoma are excellent with 5-year event-free survival and overall survival>80%. Treatment failures include radiation-induced glioblastomas (RIG), which are often diagnosed solely on imaging. Recent studies suggest that RIGs differ from spontaneous glioblastoma multiforme (GBM), based on microarray gene-expression profiling. Retrospective review of children with average-risk medulloblastoma treated from 1996 to 2003 included 16 patients with 5 treatment failures. One died of disease progression, 1 died as a result of radiation necrosis, and 3 children died of pathology-confirmed GBM. Of these 3 GBMs, one was studied with electron microscopy, cytogenetics, and gene-expression microarray analysis. This tumor had focal medulloblastoma and similarity by gene-expression microarray with other RIGs. With both components in the recurrent tumor, we suggest it was in the process of transitioning from medulloblastoma to RIG, that is, "catching the tumor in the act." Some radiation-induced nervous system tumors may develop as a direct result of severe oncologic changes within the original tumor cells, with the tumor evolving into a different phenotypic tumor type. We recommend biopsy for tissue confirmation and genetic expression profile to shed light on the etiology of radiation-induced neoplasms.

Reirradiation to the abdomen for gastrointestinal malignancies

Background

Reirradiation to the abdomen could potentially play a role in palliation of symptoms or local control in patients with gastrointestinal malignancies. Our goal was to retrospectively determine rates of toxicity, freedom from local progression and overall survival in gastrointestinal cancer patients treated with reirradiation to the abdomen.

Methods

Between November 2002 and September 2008, 13 patients with a prior history of abdominal radiotherapy (median dose 45 Gy) were treated with reirradiation for recurrent or metastatic gastrointestinal malignancies. The median interval between the two courses of radiotherapy was 26 months. Patients were treated with a hyperfractionated accelerated regimen, using 1.5 Gy fractions twice daily, with a median dose of 30 Gy (range 24-48 Gy). Concurrent chemotherapy was administered to 8 (62%) patients.

Results

The 1-year rate of freedom from local progression was 50%, and the median duration of freedom from local progression was 14 months. The 1-year rate of overall survival was 62%, and the median duration of overall survival was 14 months. One patient developed grade 3 acute toxicity (abdominal pain and gastrointestinal bleeding), requiring hospitalization during radiotherapy; subsequently, that patient experienced a grade 4 late toxicity (gastrointestinal bleeding). No other patients developed grade 3-4 acute or late toxicity or required hospitalization during radiotherapy.

Conclusion

Hyperfractionated accelerated reirradiation to the abdomen was well-tolerated with low rates of acute and late toxicity. Reirradiation could play a role in providing a limited duration of local control in gastrointestinal cancer patients with a history of prior abdominal radiotherapy.