Birgitta Lannering

Hyperfractionated Versus Conventional Radiotherapy Followed by Chemotherapy in Standard-Risk Medulloblastoma: Results From the Randomized Multicenter HIT-SIOP PNET 4 Trial

PURPOSE To compare event-free survival (EFS), overall survival (OS), pattern of relapse, and hearing loss in children with standard-risk medulloblastoma treated by postoperative hyperfractionated or conventionally fractionated radiotherapy followed by maintenance chemotherapy. PATIENTS AND METHODS In all, 340 children age 4 to 21 years from 122 European centers were postoperatively staged and randomly assigned to treatment with hyperfractionated radiotherapy (HFRT) or standard (conventional) fractionated radiotherapy (STRT) followed by a common chemotherapy regimen consisting of eight cycles of cisplatin, lomustine, and vincristine. RESULTS After a median follow-up of 4.8 years (range, 0.1 to 8.3 years), survival rates were not significantly different between the two treatment arms: 5-year EFS was 77% ± 4% in the STRT group and 78% ± 4% in the HFRT group; corresponding 5-year OS was 87% ± 3% and 85% ± 3%, respectively. A postoperative residual tumor of more than 1.5 cm(2) was the strongest negative prognostic factor. EFS of children with all reference assessments and no large residual tumor was 82% ± 2% at 5 years. Patients with a delay of more than 7 weeks to the start of RT had a worse prognosis. Severe hearing loss was not significantly different for the two treatment arms at follow-up. CONCLUSION In this large randomized European study, which enrolled patients with standard-risk medulloblastoma from more than 100 centers, excellent survival rates were achieved in patients without a large postoperative residual tumor and without RT treatment delays. EFS and OS for HFRT was not superior to STRT, which therefore remains standard of care in this disease.

Mobile Phone Use and Brain Tumors in Children and Adolescents: A Multicenter Case–Control Study

BACKGROUND It has been hypothesized that children and adolescents might be more vulnerable to possible health effects from mobile phone exposure than adults. We investigated whether mobile phone use is associated with brain tumor risk among children and adolescents. METHODS CEFALO is a multicenter case-control study conducted in Denmark, Sweden, Norway, and Switzerland that includes all children and adolescents aged 7-19 years who were diagnosed with a brain tumor between 2004 and 2008. We conducted interviews, in person, with 352 case patients (participation rate: 83%) and 646 control subjects (participation rate: 71%) and their parents. Control subjects were randomly selected from population registries and matched by age, sex, and geographical region. We asked about mobile phone use and included mobile phone operator records when available. Odds ratios (ORs) for brain tumor risk and 95% confidence intervals (CIs) were calculated using conditional logistic regression models. RESULTS Regular users of mobile phones were not statistically significantly more likely to have been diagnosed with brain tumors compared with nonusers (OR = 1.36; 95% CI = 0.92 to 2.02). Children who started to use mobile phones at least 5 years ago were not at increased risk compared with those who had never regularly used mobile phones (OR = 1.26, 95% CI = 0.70 to 2.28). In a subset of study participants for whom operator recorded data were available, brain tumor risk was related to the time elapsed since the mobile phone subscription was started but not to amount of use. No increased risk of brain tumors was observed for brain areas receiving the highest amount of exposure. CONCLUSION The absence of an exposure-response relationship either in terms of the amount of mobile phone use or by localization of the brain tumor argues against a causal association.

Irradiation-induced progenitor cell death in the developing brain is resistant to erythropoietin treatment and caspase inhibition

AbstractOne hemisphere of postnatal day 8 (P8) rats or P10 mice was irradiated with a single dose of 4–12 Gy, and animals were killed from 2 h to 8 weeks after irradiation (IR). In the subventricular zone (SVZ) and the granular cell layer (GCL) of the dentate gyrus, harboring neural and other progenitor cells, nitrosylation and p53 peaked 2–12 h after IR, followed by markers for active caspase-3, apoptosis-inducing factor and TUNEL (6–24 h). Ki67-positive (proliferating) cells had disappeared by 12 h and partly reappeared by 7 days post-IR. The SVZ and GCL areas decreased approximately 50% 7 days after IR. The development of white matter was hampered, resulting in 50–70% less myelin basic protein staining. Pretreatment with erythropoietin did not confer protection against IR. Caspase inhibition by overexpression of XIAP prevented caspase-9 and caspase-3 activation but not cell death, presumably because of increased caspase-independent cell death.

Age‐dependent sensitivity of the developing brain to irradiation is correlated with the number and vulnerability of progenitor cells

In a newly established model of unilateral, irradiation (IR)‐induced injury we compared the outcome after IR to the immature and juvenile brain, using rats at postnatal days 9 or 23, respectively. We demonstrate that (i) the immature brains contained more progenitors in the subventricular zone (SVZ) and subgranular zone (SGZ) compared with the juvenile brains; (ii) cellular injury, as judged by activation of caspase 3 and p53, as well as nitrotyrosine formation, was more pronounced in the SVZ and SGZ in the immature brains 6 h after IR; (iii) the number of progenitor and immature cells in the SVZ and SGZ decreased 6 h and 7 days post‐IR, corresponding to acute and subacute effects in humans, respectively, these effects were more pronounced in immature brains; (iv) myelination was impaired after IR at both ages, and much more pronounced after IR to immature brains; (v) the IR‐induced changes remained significant for at least 10 weeks, corresponding to late effects in humans, and were most pronounced after IR to immature brains. It appears that IR induces both an acute loss of progenitors through apoptosis and a perturbed microenvironment incompatible with normal proliferation and differentiation, and that this is more pronounced in the immature brain.

Radiobiological risk estimates of adverse events and secondary cancer for proton and photon radiation therapy of pediatric medulloblastoma.

Abstract Introduction. The aim of this model study was to estimate and compare the risk of radiation-induced adverse late effects in pediatric patients with medulloblastoma (MB) treated with either three-dimensional conformal radiotherapy (3D CRT), inversely-optimized arc therapy (RapidArc® (RA)) or spot-scanned intensity-modulated proton therapy (IMPT). The aim was also to find dose-volume toxicity parameters relevant to children undergoing RT to be used in the inverse planning of RA and IMPT, and to use in the risk estimations. Material and methods. Treatment plans were created for all three techniques on 10 pediatric patients that have been treated with craniospinal irradiation (CSI) at our institution in 2007–2009. Plans were generated for two prescription CSI doses, 23.4 Gy and 36 Gy. Risk estimates were based on childhood cancer survivor data when available and secondary cancer (SC) risks were estimated as a function of age at exposure and attained age according to the organ-equivalent dose (OED) concept. Results. Estimates of SC risk was higher for the RA plans and differentiable from the estimates for 3D CRT at attained ages above 40 years. The risk of developing heart failure, hearing loss, hypothyroidism and xerostomia was highest for the 3D CRT plans. The risks of all adverse effects were estimated as lowest for the IMPT plans, even when including secondary neutron (SN) irradiation with high values of the neutron radiation weighting factors (WRneutron). Conclusions. When comparing RA and 3D CRT treatment for pediatric MB it is a matter of comparing higher SC risk against higher risks of non-cancer adverse events. Considering time until onset of the different complications is necessary to fully assess patient benefit in such a comparison. The IMPT plans, including SN dose contribution, compared favorably to the photon techniques in terms of all radiobiological risk estimates.

Brain tumors in childhood and adolescence in west sweden 1970–1984 epidemiology and survival

A population‐based series of 198 children, aged 0 to 16.9 years, with primary brain tumors, diagnosed from 1970 to 1984, was retrieved from the Swedish Cancer Registry. After review of slides and reclassification of histology according to the American Cancer Society, the average annual incidence rate was estimated to be 34.9 per million, which is a very high incidence compared to other countries. The age distribution was not uniform as age group 0 to 4 included more children than age groups 5 to 9 and 10 to 14. The largest subgroups were astrocytomas (25%) and primitive neuroectodermal tumor (PNET)/medulloblastomas (MB) (21%). Associated diseases were neurofibromatosis and Rubinstein‐Taybi syndrome. The overall male to female ratio was 1.08:1, the same as in the population at risk; but for PNET/MB, it was 1.8:1. The 5‐year survival for all tumors was 54%, and the 15‐year survival, 49%, with great variation between tumor subgroups.

Transient Inflammation in Neurogenic Regions after Irradiation of the Developing Brain

Abstract Kalm, M., Fukuda, A., Fukuda, H., Öhrfelt, A., Lannering, B., Björk-Eriksson, T., Blennow, K., Márky, I. and Blomgren, K. Transient Inflammation in Neurogenic Regions after Irradiation of the Developing Brain. Radiat. Res. 171, 66–76 (2009). We characterized the inflammatory response after a single dose of 8 Gy to the brains of postnatal day 9 rats. Affymetrix gene chips revealed activation of multiple inflammatory mechanisms in the acute phase, 6 h after irradiation. In the subacute phase, 7 days after irradiation, genes related to neurogenesis and cell cycle were down-regulated, but glial fibrillary acidic protein (GFAP) was up-regulated. The concentrations of 14 different cytokines and chemokines were measured using a microsphere-based xMAP™ technology. CCL2, Gro/KC and IL-1α were the most strongly up-regulated 6 h after irradiation. CCL2 was expressed in astrocytes and microglia in the dentate gyrus and the subventricular zone (SVZ). Hypertrophy, but not hyperplasia, of astrocytes was demonstrated 7 days after irradiation. In summary, we found transient activation of multiple inflammatory mechanisms in the acute phase (6 h) after irradiation and activation of astrocytes in the subacute phase (7 days) after irradiation. It remains to be elucidated whether these transient changes are involved in the persistent effects of radiation observed on neurogenesis and cognition in rodents.

Classification, incidence and survival analyses of children with CNS tumours diagnosed in Sweden 1984-2005

Aim:  Primary tumours in the central nervous system (CNS) are the second most common malignancy in childhood after leukaemia. Sweden has a high incidence and a high‐survival rate in international comparative studies. This has raised the question about the type of tumours included in the Swedish Cancer registry. We therefore compared international data to the Swedish Childhood Cancer registry.

Health and persistent functional late effects in adult survivors of childhood CNS tumours: A population-based cohort study

Survivors of central nervous system (CNS) tumours are particularly vulnerable to tumour- and treatment-related disability. We present the incidence of specific and overall functional and health-related late effects in a national adult survivor cohort. Diagnostic subgroups at particular risk for persistent sequels are identified. Data collection targeted 708 eligible >18 years old survivors, 708 parent proxies and 1000 general population controls. Functional disability including sensory and cognitive impairment, emotional status and pain was assessed using the Health Utilities Index Mark 2/3 (HUI2/3). Survivors and controls, and diagnostic subgroups were contrasted to identify the general and relative risk for late effects by sub-diagnosis. Survivors had persistent late effects in sensation, mobility, self-care and cognition. Deficits in these domains indicated clinically important disability in overall health, although indices of emotion and pain were unaffected compared to controls. Late effects tended to aggravate with time, and female survivors had poorer health. Oligodendroglioma, mixed/unspecified glioma, intracranial germ cell tumour and medulloblastoma survivors had poorest overall health. Least late effects were found for other specified/unspecified CNS tumours (including meningeoma and nerve sheath tumours), and for astrocytoma. An impact on educational, vocational and family-related outcomes, and higher utilisation of social insurance or government subsidies validated health-related sequelae in adulthood. Comparisons with controls confirm persistent disability in multiple functional domains in adult CNS tumour survivors. The heightened proportion of survivors presenting severe disability is a factor that specifically differentiates survivors from controls, although diagnostic subgroups differ significantly regarding the amount and severity of late effects.

Estimated clinical benefit of protecting neurogenesis in the developing brain during radiation therapy for pediatric medulloblastoma.

We sought to assess the feasibility and estimate the benefit of sparing the neurogenic niches when irradiating the brain of pediatric patients with medulloblastoma (MB) based on clinical outcome data. Pediatric MB survivors experience a high risk of neurocognitive adverse effects, often attributed to the whole-brain irradiation that is part of standard management. Neurogenesis is very sensitive to radiation, and limiting the radiation dose to the hippocampus and the subventricular zone (SVZ) may preserve neurocognitive function. Radiotherapy plans were created using 4 techniques: standard opposing fields, intensity-modulated radiotherapy (IMRT), intensity-modulated arc therapy (IMAT), and intensity-modulated proton therapy (IMPT). Mean dose to the hippocampus and SVZ (mean for both sites) could be limited to 88.3% (range, 83.6%-91.0%), 77.1% (range, 71.5%-81.3%), and 42.3% (range, 26.6%-51.2%) with IMAT, IMRT, and IMPT, respectively, while maintaining at least 95% of the prescribed dose in 95% of the whole-brain target volume. Estimated risks for developing memory impairment after a prescribed dose of 23.4 Gy were 47% (95% confidence interval [CI], 21%-69%), 44% (95% CI, 21%-65%), 41% (95% CI, 22%-60%), and 33% (95% CI, 23%-44%) with opposing fields, IMAT, IMRT, and IMPT, respectively. Neurogenic niche sparing during cranial irradiation of pediatric patients with MB is feasible and is estimated to lower the risks of long-term neurocognitive sequelae. Greatest sparing is achieved with intensity-modulated proton therapy, thus making this an attractive option to be tested in a prospective clinical trial.