Online quality control, hyperfractionated radiotherapy alone and reduced boost volume for standard risk medulloblastoma: long-term results of MSFOP 98

Dummy run for planning of isotoxic dose-escalated radiation therapy for glioblastoma used in the PRIDE trial (NOA-28; ARO-2024-01; AG-NRO-06)

Background

The PRIDE trial (NOA-28; ARO-2024-01; AG-NRO-06; NCT05871021) is designed to determine whether a dose escalation with 75.0 Gy in 30 fractions can enhance the median overall survival (OS) in patients with methylguanine methyltransferase (MGMT) promotor unmethylated glioblastoma compared to historical median OS rates, while being isotoxic to historical cohorts through the addition of concurrent bevacizumab (BEV). To ensure protocol-compliant irradiation planning with all study centers, a dummy run was planned and the plan quality was evaluated.

Methods

A suitable patient case was selected and the computed tomography (CT), magnetic resonance imaging (MRI) and O-(2-[18F]fluoroethyl)-L-tyrosine (FET) positron emission tomography (PET) contours were made available. Participants at the various intended study sites performed radiation planning according to the PRIDE clinical trial protocol. The treatment plans and dose grids were uploaded as Digital Imaging and Communications in Medicine (DICOM) files to a cloud-based platform. Plan quality and protocol adherence were analyzed using a standardized checklist, scorecards and indices such as Dice Score (DSC) and Hausdorff Distance (HD).

Results

Median DSC was 0.89, 0.90, 0.88 for PTV60, PTV60ex (planning target volume receiving 60.0 Gy for the standard and the experimental plan, respectively) and PTV75 (PTV receiving 75.0 Gy in the experimental plan), respectively. Median HD values were 17.0 mm, 13.9 mm and 12.1 mm, respectively. These differences were also evident in the volumes: The PTV60 had a volume range of 219.1-391.3 cc (median: 261.9 cc) for the standard plans, while the PTV75 volumes for the experimental plans ranged from 71.5-142.7 cc (median: 92.3 cc). The structures with the largest deviations in Dice score were the pituitary gland (median 0.37, range 0.00-0.69) and the right lacrimal gland (median 0.59, range 0.42-0.78).

Conclusions

The deviations revealed the necessity of systematic trainings with appropriate feedback before the start of clinical trials in radiation oncology and the constant monitoring of protocol compliance throw-out the study.

Trial registration

NCT05871021.

Neurocognitive Effects and Necrosis in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

A PENTEC review of childhood cancer survivors who received brain radiation therapy (RT) was performed to develop models that aid in developing dose constraints for RT-associated central nervous system (CNS) morbidities.

METHODS AND MATERIALS

A comprehensive literature search, through the PENTEC initiative, was performed to identify published data pertaining to 6 specific CNS toxicities in children treated with brain RT. Treatment and outcome data on survivors were extracted and used to generate normal tissue complication probability (NTCP) models.

RESULTS

The search identified investigations pertaining to 2 of the 6 predefined CNS outcomes: neurocognition and brain necrosis. For neurocognition, models for 2 post-RT outcomes were developed to (1) calculate the risk for a below-average intelligence quotient (IQ) (IQ <85) and (2) estimate the expected IQ value. The models suggest that there is a 5% risk of a subsequent IQ <85 when 10%, 20%, 50%, or 100% of the brain is irradiated to 35.7, 29.1, 22.2, or 18.1 Gy, respectively (all at 2 Gy/fraction and without methotrexate). Methotrexate (MTX) increased the risk for an IQ <85 similar to a generalized uniform brain dose of 5.9 Gy. The model for predicting expected IQ also includes the effect of dose, age, and MTX. Each of these factors has an independent, but probably cumulative effect on IQ. The necrosis model estimates a 5% risk of necrosis for children after 59.8 Gy or 63.6 Gy (2 Gy/fraction) to any part of the brain if delivered as primary RT or reirradiation, respectively.

CONCLUSIONS

This PENTEC comprehensive review establishes objective relationships between patient age, RT dose, RT volume, and MTX to subsequent risks of neurocognitive injury and necrosis. A lack of consistent RT data and outcome reporting in the published literature hindered investigation of the other predefined CNS morbidity endpoints.

Randomized phase III trial of metabolic imaging-guided dose escalation of radio-chemotherapy in patients with newly diagnosed glioblastoma (SPECTRO GLIO trial)

BACKGROUND

Glioblastoma (GBM) systematically recurs after a standard 60 Gy radio-chemotherapy regimen. Since magnetic resonance spectroscopic imaging (MRSI) has been shown to predict the site of relapse, we analyzed the effect of MRSI-guided dose escalation on overall survival (OS) of patients with newly diagnosed GBM.

METHODS

In this multicentric prospective phase III trial, patients who had undergone biopsy or surgery for a GBM were randomly assigned to a standard dose (SD) of 60 Gy or a high dose (HD) of 60 Gy with an additional simultaneous integrated boost totaling 72 Gy to MRSI metabolic abnormalities, the tumor bed and residual contrast enhancements. Temozolomide was administered concomitantly and maintained for 6 months thereafter.

RESULTS

One hundred and eighty patients were included in the study between March 2011 and March 2018. After a median follow-up of 43.9 months (95% CI [42.5; 45.5]), median OS was 22.6 months (95% CI [18.9; 25.4]) versus 22.2 months (95% CI [18.3; 27.8]) for HD, and median progression-free survival was 8.6 (95% CI [6.8; 10.8]) versus 7.8 months (95% CI [6.3; 8.6]), in SD versus HD, respectively. No increase in toxicity rate was observed in the study arm. The pseudoprogression rate was similar across the SD (14.4%) and HD (16.7%) groups. For O(6)-methylguanine-DNA methyltransferase (MGMT) methylated patients, the median OS was 38 months (95% CI [23.2; NR]) for HD patients versus 28.5 months (95% CI [21.1; 35.7]) for SD patients.

CONCLUSION

The additional MRSI-guided irradiation dose totaling 72 Gy was well tolerated but did not improve OS in newly diagnosed GBM.

TRIAL REGISTRATION

NCT01507506; registration date: December 20, 2011. https://clinicaltrials.gov/ct2/show/NCT01507506?cond=NCT01507506&rank=1.

High Radiation Dose to the Fornix Causes Symptomatic Radiation Necrosis in Patients with Anaplastic Oligodendroglioma

PURPOSE

Surgery, radiotherapy (RT), and chemotherapy have prolonged the survival of patients with anaplastic oligodendroglioma. However, whether RT induces long-term toxicity remains unknown. We analyzed the relationship between the RT dose to the fornix and symptomatic radiation necrosis (SRN).

MATERIALS AND METHODS

A total of 67 patients treated between 2009 and 2019 were analyzed. SRN was defined according to the following three criteria: 1) radiographic findings, 2) symptoms attributable to the lesion, and 3) treatment resulting in symptom improvement. Various contours, including the fornix, were delineated. Univariate and multivariate analyses of the relationship between RT dose and SRN, as well as receiver operating characteristic curve analysis for cut-off values, were performed.

RESULTS

The most common location was the frontal lobe (n=40, 60%). Gross total resection was performed in 38 patients (57%), and 42 patients (63%) received procarbazine, lomustine, and vincristine chemotherapy. With a median follow-up of 42 months, the median overall and progression-free survival was 74 months. Sixteen patients (24%) developed SRN. In multivariate analysis, age and maximum dose to the fornix were associated with the development of SRN. The cut-off values for the maximum dose to the fornix and age were 59 Gy (equivalent dose delivered in 2 Gy fractions) and 46 years, respectively. The rate of SRN was higher in patients whose maximum dose to the fornix was >59 Gy (13% vs. 43%, p=0.005).

CONCLUSION

The maximum dose to the fornix was a significant factor for SRN development. While fornix sparing may help maintain neurocognitive function, additional studies are needed.

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Radiotherapy-Induced Neurocognitive Dysfunction in Brain Tumor Survivors: Burden and Rehabilitation

Radiotherapy-induced neurocognitive dysfunction after cranial irradiation has an incidence of 40-100%. It may affect both children and adults, and represents a significant burden not only on ill individuals and their caregivers but also on the health care system and society in general. Multiple patient-, tumor-, and treatment-related factors may contribute to development of this complication, but its pathophysiological mechanisms are still not understood clearly. It is hoped that introduction of more advanced techniques for conformal irradiation, optimized dosimetry, and specific prophylactic measures will decrease the risk of neurocognitive decline in brain tumor survivors in the future.

Role of Radiotherapy in Patients With Relapsed Medulloblastoma

During the last three decades, the management of medulloblastoma (MBL) has made enormous progress with a multidisciplinary approach, incorporating surgery, radiotherapy (RT), and chemotherapy. Despite this improvement, 20%-30% of patients with MBL remain at risk of disease recurrence, with its relapse being possibly fatal. To date, the salvage treatment for relapse remains challenging, and various approaches have been suggested for the retreatment. In this review, I have described the characteristics of patients with relapsed MBL, patterns of relapse and the most commonly prescribed treatment. Further, I have reviewed the studies on re-irradiation and its associated issues to conclusively suggest the RT recommendations for patients with relapsed MBL.

[Pediatric Radiation Oncology in France: State of the Art]

Pediatric radiotherapy differs greatly from its practice in adults mainly because of the age (median age 6 years), which poses the problem of irradiation of healthy tissues in a growing organism, causing sequelae, difficult compliance and management of parents. These particularities require a dedicated education and specific organization that was set progressively concerning indications, quality control, exhaustive collection of native dosimetry, long-term follow-up and clinical and translational research, as well as accreditations to practice pediatric radiotherapy, in close collaboration with the French Society of Child and Adolescent Cancer and Leukemia (SFCE), under the aegis of the French Group of Pediatric Radiotherapy (GFRP). This organization is a pioneer in the development of pediatric radiotherapy quality controls, which are becoming the European standard and in the collection of native dosimetry integrated with the follow-up of possible late-effects, constituting the most important international database.

Neurocognitive function and survival in children with average-risk medulloblastoma treated with hyperfractionated radiation therapy alone: Long-term mature outcomes of a prospective study

Background

The purpose of this study was to report long-term neurocognitive and clinical outcomes in children treated for average-risk medulloblastoma with hyperfractionated radiation therapy (HFRT) alone.

Methods

Between 2006 and 2010, 20 children with rigorously staged average-risk medulloblastoma were treated on a prospective study with HFRT without upfront adjuvant systemic chemotherapy after written informed consent. HFRT was delivered as twice-daily fractions (1 Gy/fraction, 6-8 hours apart, 5 days/week) to craniospinal axis (36 Gy/36 fractions) plus conformal tumor-bed boost (32 Gy/32 fractions). Neurocognitive function was assessed at baseline and periodically on follow-up using age-appropriate intelligence quotient (IQ) scales.

Results

Median age was 8 years (range 5-14 years) with 70% being males. Mean and standard deviation (SD) scores at baseline were 90.5 (SD = 17.08), 88 (SD = 16.82) and 88 (SD = 17.24) for Verbal Quotient (VQ), Performance Quotient (PQ), and Full-Scale IQ (FSIQ) respectively. Mean scores remained stable in the short-to-medium term but declined gradually beyond 5 years with borderline statistical significance for VQ (P = .042), but nonsignificant decline in PQ (P = .259) and FSIQ (P = .108). Average rate of neurocognitive decline was <1 IQ point per year over a 10-year period. Regression analysis stratified by age, gender, and baseline FSIQ failed to demonstrate any significant impact of the tested covariates on longitudinal neurocognitive function. At a median follow-up of 145 months, 10-year Kaplan-Meier estimates of progression-free survival and overall survival were 63.2% and 74.1% respectively.

Conclusion

HFRT alone without upfront adjuvant chemotherapy in children with average-risk medulloblastoma is associated with modest decline in neurocognitive functioning with acceptable long-term survival outcomes and may be most appropriate for resource-constrained settings.

Clinical Trials in High-Risk Medulloblastoma: Evolution of the SIOP-Europe HR-MB Trial

Medulloblastoma patients receive adapted therapies stratified according to their risk-profile. Favourable, standard, and high disease-risk groups are each defined by the status of clinical and pathological risk factors, alongside an evolving repertoire of diagnostic and prognostic biomarkers. Medulloblastoma clinical trials in Europe are coordinated by the International Society for Paediatric Oncology (SIOP-Europe) brain tumour group. Favourable and standard-risk patients are eligible for the SIOP-PNET5-MB clinical trial protocol. In contrast, therapies for high-risk disease worldwide have, to date, encompassed a range of different treatment philosophies, with no clear consensus on approach. Higher radiotherapy doses are typically deployed, delivered either conventionally or in hyper-fractionated/accelerated regimens. Similarly, both standard and high-dose chemotherapies were assessed. However, trials to date in high-risk medulloblastoma have commonly been institutional or national, based on modest cohort sizes, and have not evaluated the relative performance of different strategies in a randomised fashion. We describe the concepts and design of the SIOP-E high-risk medulloblastoma clinical trial (SIOP-HR-MB), the first international biomarker-driven, randomised, clinical trial for high-risk medulloblastoma. SIOP-HR-MB is programmed to recruit >800 patients in 16 countries across Europe; its primary objectives are to assess the relative efficacies of the alternative established regimens. The HR-MB patient population is molecularly and clinically defined, and upfront assessments incorporate a standardised central review of molecular pathology, radiology, and radiotherapy quality assurance. Secondary objectives include the assessment of (i) novel therapies within an upfront 'window' and (ii) therapy-associated neuropsychology, toxicity, and late effects, alongside (iii) the collection of materials for comprehensive integrated studies of biological determinants within the SIOP-HR-MB cohort.

Guide for paediatric radiotherapy procedures

A third of children with cancer receive radiotherapy as part of their initial treatment, which represents 800 paediatric irradiations per year in France carried out in 15 specialized centres approved on the recommendations of the French national cancer institute in decreasing order of frequency, the types of cancer that require irradiation are: brain tumours, neuroblastomas, Ewing's sarcomas, Hodgkin's lymphomas, soft tissue sarcomas including rhabdomyosarcomas, and nephroblastomas. The treatment guidelines follow the recommendations of the French society for childhood cancers (SFCE) or the French and European prospective protocols. The therapeutic indications, the technical and/and ballistic choices of complex cases are frequently discussed during bimonthly paediatric radiotherapy technical web-conferences. All cancers combined, overall survival being 80%, long-term toxicity logically becomes an important concern, making the preparation of treatments complex. The irradiation methods include all the techniques currently available: 3D conformational irradiation, intensity modulation radiation therapy, irradiation under normal or hypofractionated stereotaxic conditions, brachytherapy and proton therapy. We present the update of the recommendations of the French society for radiation oncology on the indications, the technical methods of realization and the organisation and the specificities of paediatric radiation oncology.

SIOP PNET5 MB Trial: History and Concept of a Molecularly Stratified Clinical Trial of Risk-Adapted Therapies for Standard-Risk Medulloblastoma

BACKGROUND

SIOP PNET5 MB was initiated in 2014 as the first European trial using clinical, histological, and molecular parameters to stratify treatments for children and adolescents with standard-risk medulloblastoma.

METHODS

Stratification by upfront assessment of molecular parameters requires the timely submission of adequate tumour tissue. In the standard-risk phase-III cohort, defined by the absence of high-risk criteria (M0, R0), pathological (non-LCA), and molecular biomarkers (MYCN amplification in SHH-MB or MYC amplification), a randomized intensification by carboplatin concomitant with radiotherapy is investigated. In the LR stratum for localized WNT-activated medulloblastoma and age <16 years, a reduction of craniospinal radiotherapy dose to 18 Gy and a reduced maintenance chemotherapy are investigated. Two additional strata (WNT-HR, SHH-TP53) were implemented during the trial.

RESULTS

SIOP PNET5 MB is actively recruiting. The availability of adequate tumour tissue for upfront real-time biological assessments to assess inclusion criteria has proven feasible.

CONCLUSION

SIOP PNET5 MB has demonstrated that implementation of biological parameters for stratification is feasible in a prospective multicentre setting, and may improve risk-adapted treatment. Comprehensive research studies may allow assessment of additional parameters, e.g., novel medulloblastoma subtypes, and identification and validation of biomarkers for the further refinement of risk-adapted treatment in the future.

Radiotherapy in Medulloblastoma-Evolution of Treatment, Current Concepts and Future Perspectives

Simple Summary

Craniospinal irradiation (CSI) is the backbone of medulloblastoma treatment and the first treatment to achieve a cure in many patients. Within the last decades, significant efforts have been made to enhance efficacy in combination with chemotherapy. With this approach, a majority of low- and standard-risk patients can be cured. In parallel, many clinical trials have dealt with CSI-dose reduction and reduction of boost volume in order to decrease long-term toxicity, particularly neurotoxicity. Within these trials, standardized quality assurance has helped to increase the accuracy of treatment and improve prognosis. More recently, advances of radiotherapy techniques such as proton treatment allowed for better sparing of healthy tissue in order to further diminish detrimental long-term effects. Major future challenges are the adaption of radiotherapy regimens to different molecularly defined disease groups alone or together with new targeted agents. Moreover, and even more importantly, innovative combinatorial treatments are needed in high- and very-high risk situations.

Abstract

Medulloblastoma is the most frequent malignant brain tumor in children. During the last decades, the therapeutic landscape has changed significantly with craniospinal irradiation as the backbone of treatment. Survival times have increased and treatments were stratified according to clinical and later molecular risk factors. In this review, current evidence regarding the efficacy and toxicity of radiotherapy in medulloblastoma is summarized and discussed mainly based on data of controlled trials. Current concepts and future perspectives based on current risk classification are outlined. With the introduction of CSI, medulloblastoma has become a curable disease. Due to combination with chemotherapy, survival rates have increased significantly, allowing for a reduction in radiation dose and a decrease of toxicity in low- and standard-risk patients. Furthermore, modern radiotherapy techniques are able to avoid side effects in a fragile patient population. However, high-risk patients remain with relevant mortality and many patients still suffer from treatment related toxicity. Treatment needs to be continually refined with regard to more efficacious combinatorial treatment in the future.

Prognostic relevance of clinical and molecular risk factors in children with high-risk medulloblastoma treated in the phase II trial PNET HR+5

BACKGROUND

High-risk medulloblastoma is defined by the presence of metastatic disease and/or incomplete resection and/or unfavorable histopathology and/or tumors with MYC amplification. We aimed to assess the 3-year progression-free survival (PFS) and define the molecular characteristics associated with PFS in patients aged 5-19 years with newly diagnosed high-risk medulloblastoma treated according to the phase II trial PNET HR+5.

METHODS

All children received postoperative induction chemotherapy (etoposide and carboplatin), followed by 2 high-dose thiotepa courses (600 mg/m2) with hematological stem cell support. At the latest 45 days after the last stem cell rescue, patients received risk-adapted craniospinal radiation therapy. Maintenance treatment with temozolomide was planned to start between 1-3 months after the end of radiotherapy. The primary endpoint was PFS. Outcome and safety analyses were per protocol (all patients who received at least one dose of induction chemotherapy).

RESULTS

Fifty-one patients (median age, 8 y; range, 5-19) were enrolled. The median follow-up was 7.1 years (range: 3.4-9.0). The 3 and 5-year PFS with their 95% confidence intervals (95% CI) were 78% (65-88) and 76% (63-86), and the 3 and 5-year OS were 84% (72-92) and 76% (63-86), respectively. Medulloblastoma subtype was a statistically significant prognostic factor (P-value = 0.039) with large-cell/anaplastic being of worse prognosis, as well as a molecular subgroup (P-value = 0.012) with sonic hedgehog (SHH) and group 3 being of worse prognosis than wingless (WNT) and group 4. Therapy was well tolerated.

CONCLUSIONS

This treatment based on high-dose chemotherapy and conventional radiotherapy resulted in a high survival rate in children with newly diagnosed high-risk medulloblastoma.

Medulloblastomas associated with an APC germline pathogenic variant share the good prognosis of CTNNB1-mutated medulloblastomas

BACKGROUND

Medulloblastomas may occur in a predisposition context, including familial adenomatosis polyposis. Medulloblastomas related to a germline pathogenic variant of adenomatous polyposis coli (APC) remain rare and poorly described. Their similarities with sporadic WNT medulloblastomas still require description.

METHODS

We performed a multicentric retrospective review of 12 patients treated between 1988 and 2018 for medulloblastoma with an identified or highly suspected (personal or familial history) APC germline pathogenic variant. We report personal and familial history APC gene pathogenic variants whenever available: clinical and histologic characteristics of the medulloblastoma, treatments, and long-term outcome, including second tumor and late sequelae.

RESULTS

Medulloblastomas associated with APC pathogenic variants are mainly classic (11/11 patients, 1 not available), nonmetastatic (10/12 patients) medulloblastomas, with nuclear immunoreactivity for ß-catenin (9/9 tested cases). Ten of 11 assessable patients are disease free with a median follow-up of 10.7 years (range, 1-28 y). Secondary tumors included desmoid tumors in 7 patients (9 tumors), 1 thyroid carcinoma, 2 pilomatricomas, 1 osteoma, 1 vertebral hemangioma, and 1 malignant triton in the radiation field, which caused the only cancer-related death in our series.

CONCLUSIONS

Medulloblastomas associated with an APC pathogenic variant have an overall favorable outcome, even for metastatic tumors. Yet, long-term survival is clouded by second tumor occurrence; treatment may play some role in some of these second malignancies. Our findings raise the question of applying a de-escalation therapeutic protocol to treat patients with APC germline pathogenic variants given the excellent outcome, and reduced intensity of craniospinal irradiation may be further evaluated.

Toxicity Reduction after Craniospinal Irradiation via Helical Tomotherapy in Patients with Medulloblastoma: A Unicentric Retrospective Analysis

Objectives: Recent trials with craniospinal irradiation (CSI) via helical Tomotherapy (HT) demonstrated encouraging medulloblastoma results. In this study, we assess the toxicity profile of different radiation techniques and estimate survival rates. Materials and Methods: We reviewed the records of 46 patients who underwent irradiation for medulloblastoma between 1999 and 2019 (27 conventional radiotherapy technique (CRT) and 19 HT). Patient, tumor, and treatment characteristics, as well as treatment outcomes-local control rate (LCR), event-free survival (EFS), and overall survival (OS)-were reviewed. Acute and late adverse events (AEs) were evaluated according to the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer (RTOG/EORTC) criteria. Results: In total, 43 courses of CSI and three local RT were administered to the 46 patients: 30 were male, the median age was 7 years (range 1-56). A median total RT dose of 55 Gy (range 44-68) and a median CSI dose of 35 Gy (range, 23.4-40) was delivered. During follow-up (median, 99 months), six patients (13%) developed recurrence. The EFS rate after 5 years was 84%. The overall OS rates after 5 and 10 years were 95% and 88%, respectively. There were no treatment-related deaths. Following HT, a trend towards lower grade 2/3 acute upper gastrointestinal (p = 0.07) and subacute CNS (p = 0.05) toxicity rates was detected compared to CRT-group. The risk of late CNS toxicities, mainly grade 2/3, was significantly lower following HT technique (p = 0.003). Conclusion: CSI via HT is an efficacious treatment modality in medulloblastoma patients. In all, we detected a reduced rate of several acute, subacute, and chronic toxicities following HT compared to CRT.

Prognostic Clinical and Biologic Features for Overall Survival after Relapse in Childhood Medulloblastoma

Simple Summary

Despite progress in the biology and upfront treatment of childhood medulloblastoma, relapse is almost universally fatal. No standardized treatment has so far been established for these patients. By determining which characteristics are prognostic after relapse, treatment strategies may be optimized for each of these children. We demonstrated that molecular subgroup at diagnosis is a relevant prognostic factor of outcome after relapse. Moreover, we showed that time to relapse and the use of salvage radiotherapy at relapse might have a potential impact on post-relapse survival. Our data suggest that ongoing efforts toward a better understanding of the biology, timing and type of relapse would be important to understand the determinants of tumor behavior at relapse. This could help us address more specific questions on the best surveillance strategies after completion of the treatment and the introduction of risk-stratified second-line treatment strategies.

Abstract

Given the very poor prognosis for children with recurrent medulloblastoma, we aimed to identify prognostic factors for survival post-relapse in children with childhood medulloblastoma. We retrospectively collected clinico-biological data at diagnosis and main clinical characteristics at relapse of children newly diagnosed with a medulloblastoma between 2007 and 2017 at Gustave Roussy and Necker Hospital. At a median follow-up of 6.6 years (range, 0.4–12.3 years), relapse occurred in 48 out 155 patients (31%). The median time from diagnosis to relapse was 14.3 months (range, 1.2–87.2 months). Relapse was local in 9, metastatic in 22 and combined (local and metastatic) in 17 patients. Second-line treatment consisted of chemotherapy in 31 cases, radiotherapy in 9, SHH-inhibitor in four and no treatment in the remaining four. The 1-year overall survival rate post-relapse was 44.8% (CI 95%, 31.5% to 59.0%). While molecular subgrouping at diagnosis was significantly associated with survival post-relapse, the use of radiotherapy at relapse and time to first relapse (>12 months) might also have a potential impact on post-relapse survival.

Exclusive Hyperfractionated Radiation Therapy and Reduced Boost Volume for Standard-Risk Medulloblastoma: Pooled Analysis of the 2 French Multicentric Studies MSFOP98 and MSFOP 2007 and Correlation With Molecular Subgroups

PURPOSE

Medulloblastoma has recently been characterized as a heterogeneous disease with 4 distinct molecular subgroups: wingless (WNT), sonic hedgehog (SHH), group 3, and group 4, with a new definition of risk stratification. We report progression-free survival, overall survival, and long-term cognitive effects in children with standard-risk medulloblastoma exclusively treated with hyperfractionated radiation therapy (HFRT), reduced boost volume, and online quality control, and we explore the prognostic value of biological characteristics in this chemotherapy-naïve population.

METHODS AND MATERIALS

Patients with standard-risk medulloblastoma were enrolled in 2 successive prospective multicentric studies, MSFOP 98 and MSFOP 2007, and received exclusive HFRT (36 Gy, 1 Gy/fraction twice daily) to the craniospinal axis followed by a boost at 68 Gy restricted to the tumor bed (1.5 cm margin), with online quality assurance before treatment. Patients with MYC or MYCN amplification were not excluded at the time of the study. We report progression-free survival and overall survival in the global population, and according to molecular subgroups as per World Health Organization 2016 molecular classification, and we present cognitive evaluations based on the Wechsler scale.

RESULTS

Data from 114 patients included in the MSFOP 98 trial from December 1998 to October 2001 (n = 48) and in the MSFOP 2007 from October 2008 to July 2013 (n = 66) were analyzed. With a median follow-up of 16.2 (range, 6.4-19.6) years for the MSFOP 98 cohort and 6.5 (1.6-9.6) years for the MSFOP 2007 cohort, 5-year overall survival and progression-free survival in the global population were 84% (74%-89%) and 74% (65%-81%), respectively. Molecular classification was determined for 91 patients (WNT [n = 19], SHH [n = 12], and non-WNT/non-SHH [n = 60]-including group 3 [n = 9], group 4 [n = 29], and not specified [n = 22]). Our results showed more favorable outcome for the WNT-activated subgroup and a worse prognosis for SHH-activated patients. Three patients had isolated extra-central nervous system relapse. The slope of neurocognitive decline in the global population was shallower than that observed in patients with a normofractionated regimen combined with chemotherapy.

CONCLUSIONS

HFRT led to a 5-year survival rate similar to other treatments combined with chemotherapy, with a reduced treatment duration of only 6 weeks. We confirm the MSFOP 98 results and the prognostic value of molecular status in patients with medulloblastoma, even in the absence of chemotherapy. Intelligence quotient was more preserved in children with medulloblastoma who received exclusive HFRT and reduced local boost, and intelligence quotient decline was delayed compared with patients receiving standard regimen. HFRT may be appropriate for patients who do not consent to or are not eligible for prospective clinical trials; for patients from developing countries for whom aplasia or ileus may be difficult to manage in a context of high cost/effectiveness constraints; and for whom shortened duration of RT may be easier to implement.

Dose-painting multicenter phase III trial in newly diagnosed glioblastoma: the SPECTRO-GLIO trial comparing arm A standard radiochemotherapy to arm B radiochemotherapy with simultaneous integrated boost guided by MR spectroscopic imaging

Background

Glioblastoma, a high-grade glial infiltrating tumor, is the most frequent malignant brain tumor in adults and carries a dismal prognosis. External beam radiotherapy (EBRT) increases overall survival but this is still low due to local relapses, mostly occurring in the irradiation field. As the ratio of spectra of choline/N acetyl aspartate> 2 (CNR2) on MR spectroscopic imaging has been described as predictive for the site of local relapse, we hypothesized that dose escalation on these regions would increase local control and hence global survival.

Methods/design

In this multicenter prospective phase III trial for newly diagnosed glioblastoma, 220 patients having undergone biopsy or surgery are planned for randomization to two arms. Arm A is the Stupp protocol (EBRT 60 Gy on contrast enhancement + 2 cm margin with concomitant temozolomide (TMZ) and 6 months of TMZ maintenance); Arm B is the same treatment with an additional simultaneous integrated boost of intensity-modulated radiotherapy (IMRT) of 72Gy/2.4Gy delivered on the MR spectroscopic imaging metabolic volumes of CHO/NAA > 2 and contrast-enhancing lesions or resection cavity. Stratification is performed on surgical and MGMT status.

Discussion

This is a dose-painting trial, i.e. delivery of heterogeneous dose guided by metabolic imaging. The principal endpoint is overall survival. An online prospective quality control of volumes and dose is performed in the experimental arm. The study will yield a large amount of longitudinal multimodal MR imaging data including planning CT, radiotherapy dosimetry, MR spectroscopic, diffusion and perfusion imaging.

Trial registration

NCT01507506, registration date December 20, 2011.

Recurrent extraneural sonic hedgehog medulloblastoma exhibiting sustained response to vismodegib and temozolomide monotherapies and inter-metastatic molecular heterogeneity at progression

Background

Response to targeting and non-targeting agents is variable and molecular information remains poorly described in patients with recurrent sonic-hedgehog-driven medulloblastoma (SHH-MB).

Materials and Methods

Clinical and PET/CT findings during treatment with successive hedgehog antagonists and temozolomide monotherapies are described in a heavily pre-treated patient with recurrent extraneural metastases from PTCH1 mutated/ wild type smoothened (SMO) CNS SHH-MB. Molecular tests were prospectively performed in tissue from two extraneural sites at progression.

Results

Sustained clinical/metabolic response was obtained to vismodegib. At progression, itraconazole was ineffective, but salvage temozolomide treatment results in a response similar to vismodegib. At further progression, acquired SMO and PIK3CA mutations were identified in bone (G477L and H1047A, respectively) and epidural (L412P and H1065L, respectively) metastases. No response was observed with subsequent sonidegib treatment.

Conclusions

This is the first clinical report of recurrent extraneural PTCH1 mutated SHH-MB exhibiting: 1) a sustained response to vismodegib and temozolomide, and 2) inter-metastatic molecular heterogeneity and acquired SMO-G477L, SMO-L412P, and PIK3CA-H1065L mutations at progression, highlighting the need for a multitarget treatment approach.

Long-term Survivors of Childhood Brain Tumors: Impact on General Health and Quality of Life

PURPOSE OF REVIEW

We review and summarize the key issues affecting general health and quality of life (QOL) of pediatric long-term survivors of brain tumors.

RECENT FINDINGS

Long-term survivors of brain tumors are at risk of considerable late morbidity and mortality. Lengthening survival in brain tumors has highlighted the deep impact of tumor and its treatment on the physical, psychological, functional, and social health and QOL of these survivors. Evolution in tumor therapy including surgery, radiotherapy, and systemic therapies, etc., has the potential to mitigate this impact to some extent. Sensitization of health staff, policy makers, and the primary designers of clinical trials towards integration of QOL end points while measuring survival in brain tumor patients is the need of the hour. New developments in tumor therapeutics must not only provide quantitative gain but also improve the quality of survival in these long-term survivors. While majority of the issues presented pertain to survivorship in pediatric brain tumor population, similar challenges are likely to exist in young adults surviving brain tumors as well.

Long-Term Social Outcomes of Hyperfractionated Radiation on Childhood ALL Survivors

BACKGROUND/OBJECTIVES

Childhood cranial radiation has irreversible neurocognitive effects. Hyperfractionated radiation therapy (HFX) for acute lymphoblastic leukemia (ALL) was randomized against conventionally fractionated radiation therapy (CFX) in the DFCI 87-01/91-01 trials attempting to minimize these effects. When neurocognitive testing 8-year posttreatment demonstrated no difference, this strategy was abandoned. The objective of this study was to evaluate late social outcomes among patients who received HFX compared to CFX as part of the DFCI 87-01/91-01 trials.

METHODS

This retrospective chart review examined all patients treated according to the DFCI 87-01/91-01 trials at the McMaster Children's Hospital in Hamilton, Canada. Patients <18 years at diagnosis and who have attended follow-up clinic since January 1, 2000 were included in this study. Social outcomes and IQ test results were examined for trends. Demographics and outcomes were presented with descriptive statistics.

RESULTS

We identified 57 DFCI 87-01/91-01 trial participants: 14 received HFX, 29 received CFX, and 14 received no radiation. There were no demographic differences between the groups. HFX survivors were more likely to be living independently (64% vs. 28%, P = 0.02) and engaged in long-term relationships (57% vs. 25%, P = 0.04) than CFX. Nonsignificant trends suggested that HFX survivors may be more financially independent, employed full-time, had fewer educational difficulties in school, and higher scores on neuropsychological testing. Data trends, although not significant, persisted in logistic regression analysis when accounting for age.

CONCLUSION

Long-term social outcomes were better among ALL survivors who received HFX than CFX. A wider study involving all patients enrolled on DFCI 87-01/91-01 protocols should be conducted to reconsider radiation protocols for ALL.

[Therapeutic outcomes of medulloblastoma in Casablanca from 2000 to 2012]

PURPOSE

To describe the therapeutic results, with the aim to contribute to improving the care of patients with medulloblastoma.

PATIENTS AND METHODS

A retrospective study of 69 cases of medulloblastoma collected in the university hospital Ibn Rochd of Casablanca between 2000 and 2012.

RESULTS

Fifty-three children with an average age of 9 years and 16 adults with an average age of 32.4 years were included in the study. Thirty-seven children and eight adults suffered from a high-risk tumour. The radiotherapy was received by all patients with a mean dose of 36 Gy to the whole brain and 54 Gy in the posterior fossa. All patients in the paediatric group and 10 patients in the adult group received concomitant chemotherapy, 44 children and four adults received adjuvant chemotherapy. Tumour recurrence was observed in 17 children after a mean follow-up period of 38 months. These recurrences were observed in five adults after a mean follow-up period of 42 months. The posterior fossa was the main site of relapses. Overall survival was 77.7% for the children and 61% for the adults. Overall survival was better (70% versus 25%) when the interval between radiotherapy and surgery was less than 40 days in the paediatric group. The recurrence rate was significantly higher for the high-risk group: 41% versus 13% for the standard risk. In the adult group, overall survival differences according to the risk group were significant (100% for the standard risk versus 37.5% for the high risk).

CONCLUSION

The overall survival and recurrences rate obtained are encouraging. The risk group and time between surgery and radiotherapy were prognostic factors with significant impact on survival depending on the age group. We recommend reducing these times to improve therapeutic results.

Paediatric brain tumours: A review of radiotherapy, state of the art and challenges for the future regarding protontherapy and carbontherapy

BACKGROUND AND PURPOSE

Brain tumours are the most frequent solid tumours in children and the most frequent radiotherapy indications in paediatrics, with frequent late effects: cognitive, osseous, visual, auditory and hormonal. A better protection of healthy tissues by improved beam ballistics, with particle therapy, is expected to decrease significantly late effects without decreasing local control and survival. This article reviews the scientific literature to advocate indications of protontherapy and carbon ion therapy for childhood central nervous system cancer, and estimate the expected therapeutic benefits.

MATERIALS AND METHODS

A systematic review was performed on paediatric brain tumour treatments using Medline (from 1966 to March of 2014). To be included, clinical trials had to meet the following criteria: age of patients 18 years or younger, treated with radiation, and report of survival. Studies were also selected according to the evidence level. A secondary search of cited references found other studies about cognitive functions, quality of life, the comparison of photon and proton dosimetry showing potential dose escalation and/or sparing of organs at risk with protontherapy; and studies on dosimetric and technical issues related to protontherapy.

RESULTS

A total of 7051 primary references published were retrieved, among which 40 clinical studies and 60 papers about quality of life, dose distribution and dosimetry were analysed, as well as the ongoing clinical trials. These papers have been summarized and reported in a specific document made available to the participants of a final 1-day workshop. Tumours of the meningeal envelop and bony cranial structures were excluded from the analysis. Protontherapy allows outstanding ballistics to target the tumour area, while substantially decreasing radiation dose to the normal tissues. There are many indications of protontherapy for paediatric brain tumours in curative intent, either for localized treatment of ependymomas, germ-cell tumours, craniopharyngiomas, low-grade gliomas; or panventricular irradiation of pure non-secreting germinoma; or craniospinal irradiation of medulloblastomas and metastatic pure germinomas. Carbon ion therapy is just emerging and may be studied for highly aggressive and radioresistant tumours, as an initial treatment for diffuse brainstem gliomas, and for relapse of high-grade gliomas.

CONCLUSION

Both protontherapy and carbon ion therapy are promising for paediatric brain tumours. The benefit of decreasing late effects without altering survival has been described for most paediatric brain tumours with protontherapy and is currently assessed in ongoing clinical trials with up-to-date proton devices. Unfortunately, in 2015, only a minority of paediatric patients in France can receive protontherapy due to the lack of equipment.

Optimization of Craniospinal Irradiation for Pediatric Medulloblastoma Using VMAT and IMRT

PURPOSE

Intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) provide highly conformal target radiation doses, but also expose large volumes of healthy tissue to low-dose radiation. With improving survival, more children with medulloblastoma (MB) are at risk of late adverse effects of radiotherapy, including secondary cancers. We evaluated the characteristics of IMRT and VMAT craniospinal irradiation treatment plans in children with standard-risk MB to compare radiation dose delivery to target organs and organs at risk (OAR).

PATIENTS AND METHODS

Each of 10 children with standard-risk MB underwent both IMRT and VMAT treatment planning. Dose calculations used inverse planning optimization with a craniospinal dose of 23.4 Gy followed by a posterior fossa boost to 55.8 Gy. Clinical and planning target volumes were demarcated on axial computed tomography images. Dose distributions to target organs and OAR for each planning technique were measured and compared with published dose-volume toxicity data for pediatric patients.

RESULTS

All patients completed treatment planning for both techniques. Analyses and comparisons of dose distributions and dose-volume histograms for the planned target volumes, and dose delivery to the OAR for each technique demonstrated the following: (1) VMAT had a modest, but significantly better, planning target volume-dose coverage and homogeneity compared with IMRT; (2) there were different OAR dose-sparing profiles for IMRT versus VMAT; and (3) neither IMRT nor VMAT demonstrated dose reductions to the published pediatric dose limits for the eyes, the lens, the cochlea, the pituitary, and the brain.

CONCLUSIONS

The use of both IMRT and VMAT provides good target tissue coverage and sparing of the adjacent tissue for MB. Both techniques resulted in OAR dose delivery within published pediatric dose guidelines, except those mentioned above. Pediatric patients with standard-risk MB remain at risk for late endocrinologic, sensory (auditory and visual), and brain functional impairments.

Clinical Outcomes Among Children With Standard-Risk Medulloblastoma Treated With Proton and Photon Radiation Therapy: A Comparison of Disease Control and Overall Survival

PURPOSE

The purpose of this study was to compare long-term disease control and overall survival between children treated with proton and photon radiation therapy (RT) for standard-risk medulloblastoma.

METHODS AND MATERIALS

This multi-institution cohort study includes 88 children treated with chemotherapy and proton (n=45) or photon (n=43) RT between 2000 and 2009. Overall survival (OS), recurrence-free survival (RFS), and patterns of failure were compared between the 2 cohorts.

RESULTS

Median (range) age was 6 years old at diagnosis (3-21 years) for proton patients versus 8 years (3-19 years) for photon patients (P=.011). Cohorts were similar with respect to sex, histology, extent of surgical resection, craniospinal irradiation (CSI) RT dose, total RT dose, whether the RT boost was delivered to the posterior fossa (PF) or tumor bed (TB), time from surgery to RT start, or total duration of RT. RT consisted of a median (range) CSI dose of 23.4 Gy (18-27 Gy) and a boost of 30.6 Gy (27-37.8 Gy). Median follow-up time is 6.2 years (95% confidence interval [CI]: 5.1-6.6 years) for proton patients versus 7.0 years (95% CI: 5.8-8.9 years) for photon patients. There was no significant difference in RFS or OS between patients treated with proton versus photon RT; 6-year RFS was 78.8% versus 76.5% (P=.948) and 6-year OS was 82.0% versus 87.6%, respectively (P=.285). On multivariate analysis, there was a trend for longer RFS with females (P=.058) and higher CSI dose (P=.096) and for longer OS with females (P=.093). Patterns of failure were similar between the 2 cohorts (P=.908).

CONCLUSIONS

Disease control with proton and photon radiation therapy appears equivalent for standard risk medulloblastoma.

[Which dose constraints on which critical organs in paediatric radiation therapy?]

Cancers in childhood are rare, representing 1% of all the cancers in developing countries. On the whole, the overall survival approaches 75% at 5 years. The radiation dose decrease in lots of indications as well as better optimized planning treatments lead to decrease the long-term toxicities in some indications. However, the radiation toxicity remains frequent, often specific of pediatric situations. Long-term toxicities are mainly neurologic, sensitive, endocrine, or linked to growth impairment (bones or muscular). Radio-induced second-cancers are also frequent after a long follow-up after cancer in childhood but will not be discussed here. Doses to critical organs as well as the most frequent radio-induced late-effects will be discussed in this paper.

[Evolution of the management of pediatric and adult medulloblastoma]

Medulloblastoma are cerebellar tumours belonging to the group of primitive neuroectodermal tumours (PNET) and are the most common malignant brain tumours of childhood. These tumours are rare and heterogeneous, requiring some multicentric prospective studies and multidisciplinary care. The classical therapeutic approaches are based on clinical, radiological and surgical data. They involve surgery, radiation therapy and chemotherapy. Some histological features were added to characterize risk. More recently, molecular knowledge has allowed to devise risk-adapted strategies and helped to define groups with good outcome and reduce long-term sequelae, improve the prognostic of high-risk medulloblastoma and develop new therapeutic tools.

Local control in non-metastatic medulloblastoma

BACKGROUND

A single-institution review of long-term outcomes and factors affecting local control (LC) following radiotherapy for non-metastatic medulloblastoma.

MATERIAL AND METHODS

From 1963 to 2008, 50 children (median age, 7.3 years; range 1.2-18.5) with stage M0 medulloblastoma were treated with radiotherapy; half underwent a gross total resection (no visible residual tumor) or near-total resection (< 1.5 cm(3) of gross disease remaining after resection). Median craniospinal dose was 28.8 Gy (range 21.8-38.4 Gy). Median total dose to the posterior fossa was 54.3 Gy (range 42.4-64.8 Gy). Eighteen patients (36%) received chemotherapy as part of multimodality management, including 11 who received concurrent chemotherapy.

RESULTS

Median follow-up was 15.7 years (range 0.3-44.4 years) for all patients and 26.6 years (range 7.3-44.4 years) for living patients. The 10-year overall survival, cancer-specific survival, and progression-free survival rates were 65%, 65%, and 69%. The 10-year LC rate was 84% and did not significantly change across eras. Four percent of patients experienced local progression five years after treatment. On univariate analysis, chemotherapy and overall duration of radiotherapy ≤ 45 days were associated with improved LC. Patients receiving chemotherapy had a 10-year 100% LC rate versus 76% in patients not receiving chemotherapy (p = 0.0454). When overall radiotherapy treatment lasted ≤ 45 days, patients experienced a superior 95% 10-year LC rate (vs. 73% in patients treated > 45 days; p = 0.0419). Three patients (6%) died from treatment complications, including radionecrosis/cerebellar degeneration, severe cerebral edema leading to herniation, and secondary malignancy.

CONCLUSIONS

While we cannot draw definitive conclusions given the retrospective nature of our study, our long-term data suggest that reductions in craniospinal dose and boost target volume to reduce toxicity have not compromised disease control in the modern era. Our data also support analyses that implicate duration of radiotherapy, rather than interval between surgery and radiotherapy, as a factor in LC. Chemotherapy in multimodality management of medulloblastoma may have an underappreciated role in improving LC rates.

Developing interventions for cancer-related cognitive dysfunction in childhood cancer survivors

Survivors of childhood cancer frequently experience cancer-related cognitive dysfunction, commonly months to years after treatment for pediatric brain tumors, acute lymphoblastic leukemia (ALL), or tumors involving the head and neck. Risk factors for cancer-related cognitive dysfunction include young age at diagnosis, treatment with cranial irradiation, use of parenteral or intrathecal methotrexate, female sex, and pre-existing comorbidities. Limiting use and reducing doses and volume of cranial irradiation while intensifying chemotherapy have improved survival and reduced the severity of cognitive dysfunction, especially in leukemia. Nonetheless, problems in core functional domains of attention, processing speed, working memory and visual-motor integration continue to compromise quality of life and performance. We review the epidemiology, pathophysiology and assessment of cancer-related cognitive dysfunction, the impact of treatment changes for prevention, and the broad strategies for educational and pharmacological interventions to remediate established cognitive dysfunction following childhood cancer. The increased years of life saved after childhood cancer warrants continued study toward the prevention and remediation of cancer-related cognitive dysfunction, using uniform assessments anchored in functional outcomes.

High-dose busulfan-thiotepa with autologous stem cell transplantation followed by posterior fossa irradiation in young children with classical or incompletely resected medulloblastoma

BACKGROUND

The aim of the study is to evaluate the outcome of young children with high risk localized medulloblastomas (newly diagnosed classical or incompletely resected) treated by high-dose busulfan-thiotepa with autologous stem cell rescue (ASCT) followed by focal radiation therapy (RT).

PROCEDURE

Between September 1994 and January 2010, 19 children younger than 5 years old at diagnosis fulfilling the above inclusion criteria were treated at the Institute Gustave Roussy. After conventional chemotherapy, they received busulfan at a dose of 600 mg/m(2) and thiotepa at a dose of 900 mg/m(2) followed by ASCT. Focal RT was delivered at least 70 days after ASCT.

RESULTS

The median follow-up was 40.5 months (range, 14.5-191.2 months). The 3-year event-free survival (EFS) and OS were 68% (95% CI 45-84%) and 84% (95% CI 61-94%), respectively. Acute toxicity consisted mainly in hepatic veno-occlusive disease (6/19 patients) and bone marrow aplasia (all patients). No toxic death occurred. The Full Scale Intellectual Quotient tended to decrease over time at a mean rate of 0.9 point per year from the date of diagnosis.

CONCLUSIONS

This intensive treatment resulted in a high overall survival rate in young children with newly diagnosed non-metastatic classic or incompletely resected MB. In spite of a high incidence of hepatic veno-occlusive disease (32%), the acute toxicity was manageable. Delayed neuropsychological side effects remain main concerns. These results should to be confirmed in a larger cohort.

Patterns of failure after proton therapy in medulloblastoma; linear energy transfer distributions and relative biological effectiveness associations for relapses

PURPOSE

The pattern of failure in medulloblastoma patients treated with proton radiation therapy is unknown. For this increasingly used modality, it is important to ensure that outcomes are comparable to those in modern photon series. It has been suggested this pattern may differ from photons because of variations in linear energy transfer (LET) and relative biological effectiveness (RBE). In addition, the use of matching fields for delivery of craniospinal irradiation (CSI) may influence patterns of relapse. Here we report the patterns of failure after the use of protons, compare it to that in the available photon literature, and determine the LET and RBE values in areas of recurrence.

METHODS AND MATERIALS

Retrospective review of patients with medulloblastoma treated with proton radiation therapy at Massachusetts General Hospital (MGH) between 2002 and 2011. We documented the locations of first relapse. Discrete failures were contoured on the original planning computed tomography scan. Monte Carlo calculation methods were used to estimate the proton LET distribution. Models were used to estimate RBE values based on the LET distributions.

RESULTS

A total of 109 patients were followed for a median of 38.8 months (range, 1.4-119.2 months). Of the patients, 16 experienced relapse. Relapse involved the supratentorial compartment (n=8), spinal compartment (n=11), and posterior fossa (n=5). Eleven failures were isolated to a single compartment; 6 failures in the spine, 4 failures in the supratentorium, and 1 failure in the posterior fossa. The remaining patients had multiple sites of disease. One isolated spinal failure occurred at the spinal junction of 2 fields. None of the 70 patients treated with an involved-field-only boost failed in the posterior fossa outside of the tumor bed. We found no correlation between Monte Carlo-calculated LET distribution and regions of recurrence.

CONCLUSIONS

The most common site of failure in patients treated with protons for medulloblastoma was outside of the posterior fossa. The most common site for isolated local failure was the spine. We recommend consideration of spinal imaging in follow-up and careful attention to dose distribution in the spinal junction regions. Development of techniques that do not require field matching may be of benefit. We did not identify a direct correlation between lower LET values and recurrence in medulloblastoma patients treated with proton therapy. Patterns of failure do not appear to differ from those in patients treated with photon therapy.

Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique

BACKGROUND

We investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy.

METHODS

We included 17 pediatric medulloblastoma patients to represent the variability in tumor location relative to the hippocampal region. Treatment plans were generated using 3D conformal radiotherapy, hippocampal sparing intensity-modulated radiotherapy, and spot-scanned proton therapy, using 3 different treatment margins for the conformal tumor boost. Neurocognitive impairment risk was estimated based on dose-response models from pediatric CNS malignancy survivors and compared among different margins and treatment techniques.

RESULTS

Mean hippocampal dose and corresponding risk of cognitive impairment were decreased with decreasing treatment margins (P < .05). The largest risk reduction, however, was seen when applying hippocampal sparing proton therapy-the estimated risk of impaired task efficiency (95% confidence interval) was 92% (66%-98%), 81% (51%-95%), and 50% (30%-70%) for 3D conformal radiotherapy, intensity-modulated radiotherapy, and proton therapy, respectively, for the smallest boost margin and 98% (78%-100%), 90% (60%-98%), and 70% (39%-90%) if boosting the whole posterior fossa. Also, the distance between the closest point of the planning target volume and the center of the hippocampus can be used to predict mean hippocampal dose for a given treatment technique.

CONCLUSIONS

We estimate a considerable clinical benefit of hippocampal sparing radiotherapy. In choosing treatment margins, the tradeoff between margin size and risk of neurocognitive impairment quantified here should be considered.

Intellectual and academic outcome following two chemotherapy regimens and radiotherapy for average-risk medulloblastoma: COG A9961

PURPOSE

Assess the intellectual and academic outcomes as well as risk factors associated with treatment for average-risk medulloblastoma in childhood using 23.4 Gy of craniospinal radiotherapy plus adjuvant chemotherapy.

METHODS

From an overall sample of 379 enrolled in the parent study (COG A9961), 110 patients received a total of 192 assessments over more than 5 years with standardized IQ and academic achievement tests. Random coefficient models of the various outcomes were developed that incorporated covariates including chemotherapy regimen, age at diagnosis, sex, initial Full Scale IQ, and mutism.

RESULTS

Participants in this study were found to be comparable to the overall sample in all demographic, disease, and treatment factors, except there were more gross total resections in the subsample undergoing intellectual and academic assessment. Major findings include significant decline in both intellectual and academic domains over time that were greater in children who were younger at diagnosis and had higher initial intelligence test scores. Children with mutism were at higher risk for initial effects on intelligence. No effects of sex were found.

CONCLUSION

These results show progressive decline over several years post-treatment in standardized intellectual and academic scores. Despite recent improvements in therapies for these children, most notably a decrease dose of craniospinal radiation, they remain at risk. The pursuit of less toxic treatments, particularly for younger children, should continue. Neuropsychological surveillance should be routine at centers treating children with brain tumors.

Factors affecting functional outcomes in long-term survivors of intracranial germinomas: a 20-year experience in a single institution

OBJECT

Radiation monotherapy-prophylactic craniospinal or whole-brain irradiation paired with a radiation boost to the primary tumor-is the standard treatment for intracranial germinomas at the authors' institution. The authors assessed long-term outcomes of patients with germinoma who underwent therapy and identified factors affecting them.

METHODS

The authors retrospectively analyzed data obtained in 46 patients (35 males and 11 females, age 5-43 years at diagnosis) who had been treated for intracranial germinomas between 1990 and 2009 at the authors' institution. Thirty patients had germinomas in localized regions and 16 in multiple regions. Thirty-eight patients (83%) underwent radiotherapy alone (craniospinal irradiation in 32 and whole-brain irradiation in 6). Seven patients underwent radiochemotherapy and 1 underwent chemotherapy alone. The mean radiation doses for the whole brain, spine, and primary tumor site were 26.9, 26.6, and 49.8 Gy, respectively. The median follow-up period was 125 months.

RESULTS

The 10-year overall and recurrence-free survival rates were 93.3% and 89.3%, respectively. None of the 38 patients who received radiation monotherapy developed a recurrent lesion, whereas 1 of 7 who underwent radiochemotherapy and the 1 patient who underwent chemotherapy had a recurrent lesion. Of the entire population, 26 patients required hormone replacement therapy, 2 had short stature, and 1 developed a radiation-induced meningioma. Seventeen of the 25 childhood- or adolescent-onset patients were 19 years or older at the latest follow-up visit, 15 of whom graduated from senior high school, and only 2 of whom graduated from college. Of 34 patients who were 19 years or older at the latest visit, 4 were students, 18 worked independently, 4 worked in sheltered workplaces, and 8 were unemployed. Of the 34 patients, 4 got married after the initial treatment, 3 of whom had children. There were 8 patients (17%) with low postoperative Karnofsky Performance Scale (KPS) scores that were significantly associated with impaired neurocognitive functions, severe surgical complications, and neurological impairments. In 10 of the 46 patients, KPS scores at the latest visit were lower than their postoperative KPS scores. These decreases in KPS scores were significantly correlated with a delayed decline in neurocognitive functions in childhood-onset patients and a postoperative impairment of neurocognitive functions in patients with adolescent- or adult-onset germinoma.

CONCLUSIONS

No tumor recurrence occurred in germinoma patients treated with the authors' radiation monotherapy, which appears to be effective enough to cure the tumor. Brain damage caused by tumors themselves and surgical complications were found to adversely affect functional outcomes in patients regardless of their age. Although radiotherapy rarely caused late adverse effects in patients with adolescent- or adult-onset, in some childhood-onset lesions, the radiation seems to carry the risk of neurocognitive dysfunctions, which are attributable to late adverse effects. Accordingly, treatments for germinoma patients should be selected according to a patient's age and the extent of the tumor and with particular care to avoid surgical complications.

Central nervous system tumors

Central nervous system tumors are the most frequent malignant tumor in children and the main cause of death in this age group after traffic accidents. The current estimates are that one adult in 2500 is a survivor of a brain tumor that occurred during childhood. These tumors are particularly heterogeneous in terms of histology/biology, treatment, and outcome. They share, however, a high risk of neurological and cognitive morbidity due to the disease itself and the treatment modalities (radiotherapy, surgery, and chemotherapy). Diagnosis is frequently delayed because symptoms are usually nonspecific at the beginning of the evolution. Posterior fossa is the most frequent site and the tumors present most frequently with signs of intracranial hypertension. Supratentorial tumors are more frequent in infants and in adolescents; seizures are not uncommon, especially for benign tumors. When adjuvant treatment is needed, radiotherapy is usually the mainstay apart from some histologies where chemotherapy may be sufficient: low-grade gliomas, desmoplastic medulloblastomas, malignant glial tumors in infants. Multidisciplinary care is best performed in tertiary care centers and should include early rehabilitation programs soon after surgery.