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Purpose: The aim of the study is to evaluate treatment-related acute and late eye toxicity associated with radiation therapy in childhood and adolescence as correlated with RT (radiotherapy) doses., Methods: From 2001 to 2016, a total of 1725 children and adolescents undergoing radiation therapy were prospectively documented in the Registry of the Evaluation of Side Effects after Radiotherapy in Childhood and Adolescence (RiSK). The RTOG/EORTC criteria were used to classify ocular acute and late effects. Uni- and multivariate analyses were carried out to evaluate the impact of patient age, pre-existing impairments, and radiation dose on ocular toxicity., Results: Of all documented patients, 593 received dose to the eye and formed the basis of this analysis. In 435 patients, information on acute reaction was available and graded 1, 2, 3, and 4 in 49, 17, 0, and 2 patients, respectively. Information on late toxicity was available in 268 patients and graded 1, 2, 3, and 4 in 15, 11, 11, and 5 patients, respectively. The acute toxicity rate was significantly higher in children who received a maximum dose > 50 Gy to the eye (p < 0.001) and who had a pre-existing eye impairment (p < 0.001 in multivariate analysis). The development of late toxicity was significantly higher for patients experiencing acute toxicity and having received a radiation dose > 50 Gy., Conclusion: Acute and late toxicity both correlate with high radiation dose to the eye (> 50 Gy) and acute toxicity additionally with pre-existing eye impairments., (© 2021. The Author(s).)

Background and Purpose: The "Registry for the evaluation of side effects after radiation in childhood and adolescence" (risk) was introduced to characterize adverse effects of radiotherapy in childhood and adolescence prospectively. The aim of this analysis was to characterize the pattern of acute side effects., Materials and Methods: Since 2001, patients receiving radiotherapy in one of the German pediatric therapy trials have been registered in RiSK with detailed information regarding radiation doses to organs at risk and characterization of acute toxicities., Results: From 2001 to May 2009, 690 patients have been characterized for acute toxicity in primary therapy. Acute toxicity ≥ grade 1 was observed in 506 patients. In patients irradiated in their lung and liver, patients with grade 1 or 2 acute toxicities showed higher organ volumes exposed to radiation doses <20 Gray (Gy) compared to patients without toxicities. For the salivary glands, there was a positive correlation between the acute toxicity grade and the maximum radiation dose to the organ; the lower GI tract showed a similar trend. The impact of different chemotherapy regimens on these acute side effects remains unclear. Age did not have any impact on side effects., Conclusion: This analysis gives a comprehensive overview of the acute toxicities of radiotherapy in children and adolescents. With prolongation of follow-up, detailed analyses regarding late toxicities will be possible with the characterization of dose-volume-effect relationships., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Background and Purpose: The scattered radiation from the treatment volume might be more significant for children than for adults and, as a consequence, modern radiotherapy treatment techniques such as IMRT and passive proton therapy could potentially increase the number of secondary cancers. In this report, secondary cancer risk resulting from new treatment technologies was estimated for an adult prostate patient and a child., Material and Methods: The organ equivalent dose (OED) concept with a linear-exponential, a plateau and a linear dose-response curve was applied to dose distributions of an adult prostate patient and a child with a rhabdomyosarcoma of the prostate. Conformal radiotherapy, IMRT with 6MV photons and proton therapy were planned. OED (cancer risk) was estimated for the whole body, the rectum and the bladder. In addition, relative cumulative risk was calculated., Results: Secondary cancer risk in the adult is not more than 15% it increased when IMRT or passive proton therapy was compared to conventional treatment planning. In the child, risk remains practically constant or was even reduced for proton therapy. The cumulative risk in the child relative to that in the adult can be as large as 10-15., Conclusions: By a comparison between an adult patient and a child treated for a disease of the prostate, it was shown that modern radiotherapy techniques such as IMRT and proton therapy (active and passive) do not increase the risk for secondary cancers.

Background: Late effects after radiotherapy in childhood and adolescence have mainly been characterized retrospectively with small patient numbers. However, these analyses are limited due to little information regarding organ dose levels in many cases. To overcome this limitation, the German Group of Paediatric Radiation Oncology (APRO) established the "Registry for the evaluation of late side effects after radiation in childhood and adolescence" (RiSK). The study protocol and the documentation forms are given in this publication., Methods/design: Radiation parameters including detailed organ doses as well as toxicity evaluations are collected prospectively from centres all over Germany. Standardized documentation forms are used. These forms are given in an English and German version as additional files to this publication. Documentation is planned for all children who receive radiotherapy in one of the therapy trials of the "German Society of Paediatric Oncology and Haematology (GPOH)". The study started in a pilot phase in June 2001 in few centres. Since 2004 documentation has been performed all over Germany and is still on-going., Discussion: To our knowledge, "RiSK" is the only multi-centre study that evaluates radiation associated side effects prospectively with detailed information about organ dose levels. With ongoing recruitment and prolongation of follow-up powerful data will be obtained in a few years. A broad use and international cooperation are welcome.

Background and Purpose: Radiogenic late effects in children and adolescents have been evaluated retrospectively in most analyses, with small patient numbers. The German Group of Pediatric Radiation Oncology (APRO) has generated a concept for a prospective evaluation of radiation-associated late effects in childhood. The aim of this study was to evaluate the feasibility of a nationwide central database for the documentation of radiation parameters and side effects of all children treated within therapy protocols of the German Society of Pediatric Oncology and Hematology (GPOH)., Patients and Methods: A study center has been implemented in Muenster, the documentation has started in July 2001 in few centers in a pilot phase. Since February 2004 the documentation is done countrywide. Detailed documentation forms have been designed for treatment parameters and for doses applied at organs at risk. Furthermore, a uniform toxicity documentation, according to the RTOG/EORTC criteria, was chosen. Patients were reported from the study centers of the GPOH to the study center. All information was collected and analyzed in the study center., Results: Till July 31, 2005, 438 documentations of radiation and 579 toxicity documentations of side effects have been collected in the study center. 46 centers for radiotherapy in Germany and one center each in Austria and in Switzerland took part in the documentation. The quality of documentation regarding completeness and plausibility fulfilled the expected criteria in most cases. This feasibility analysis showed that important information about organ dose levels and side effects was documented in a large number of patients (Figures 1 and 2)., Conclusion: This prospective evaluation of radiotherapy and radiogenic side effects in children and adolescents will allow correlating doses at organs at risk and the incidence of acute and late sequelae in Germany. Further documentations and a longer follow-up are necessary to obtain powerful results.

Background: For more than 60 years, radiation therapy has been an integral part in the management of childhood low-grade glioma. As this tumor carries an excellent long-term prognosis, the risk of late effects is of particular clinical importance and impinges upon radiotherapeutic treatment strategies., Material and Methods: Studies on the use of radiation therapy in children with low-grade glioma were systematically reviewed for data on radiotherapy-induced side effects on brain parenchyma, endocrine dysfunction, growth retardation, neurocognitive dysfunction, vasculopathy, and secondary neoplasms., Results: Data on late effects are scarce and heterogeneous. Past reports included only retrospective series from the 1930s to present days, a time during which treatment policies and radiation techniques widely varied and considerably changed in recent years. Often, considerable uncertainty existed regarding pretreatment health status and radiotherapy-related factors (e.g., total dose, dose per fraction, treatment fields). In spite of these shortcomings and often conflicting observations, it appears that especially younger children and children with neurofibromatosis (NF) are at risk of endocrinopathies in terms of growth retardation and developmental abnormalities, as well as neurocognitive dysfunction expressed as problems in the psychosocial environment such as in education and occupation. However, both observations may be attributed to the higher proportion of NF in the very young who frequently develop large tumors spreading along the entire supratentorial midline. The risk of radiation-induced disturbances in visual function is low (no case reported). Young children with NF appear to have an increased risk of vasculopathies. 33 cases of moyamoya disease were found (preferably in the very young), 18 of whom were NF-positive. Other cerebrovascular accidents (24 cases, of whom 14 were NF-positive) and secondary neoplasms (15 cases, of whom only five occurred in field--four were high-grade astrocytomas) are a rare condition. The latter cannot be distinguished from late relapses with malignant transformation. Modern treatment techniques appear to reduce the risk of radiation-induced late effects., Conclusions: More studies and clear definitions of clinical endpoints such as neurocognitive and endocrinological outcome are needed in order to clarify the impact of radiation therapy on the risk of late sequelae. Presently, the strategy to postpone radiotherapy in the younger children, especially with NF, is justified to reduce the risk of late effects. These information and the contribution of tumor, surgery and chemotherapy will help to define the role of radiation therapy in the future management of childhood low-grade glioma and whether the use of highly sophisticated and expensive treatment techniques is justifiable. The recently initiated prospective study of the APRO (Pediatric Radiooncology Working Party) on documentation of dose prescription to organs at risk and the network of the GPOH to explore late effects as well as the forthcoming prospective SIOP/GPOH (International Society of Pediatric Oncology/German Society of Pediatric Oncology and Hematology) LGG 2003 trial are addressing these issues.

Simple Summary: The treatment options for children with recurrent medulloblastoma are often limited due to extensive previously received treatments after initial diagnosis. Especially, repeated radiotherapy is associated with significant side-effects. In this study, we study the impact on survival of repeated radiotherapy at recurrence for patients with previous irradiation, as well as first irradiation at recurrence when no previous radiotherapy was applied. We find that repeated radiotherapy provides a short-time benefit in terms of survival, but survival ten years after recurrence is not significantly improved. At the same time, we find that applying radiotherapy at recurrence when patients received no previous irradiation did significantly improve survival, both short and long term. Background: Radiotherapy (RT) involving craniospinal irradiation (CSI) is important in the initial treatment of medulloblastoma. At recurrence, the re-irradiation options are limited and associated with severe side-effects. Methods: For pre-irradiated patients, patients with re-irradiation (RT2) were matched by sex, histology, time to recurrence, disease status and treatment at recurrence to patients without RT2. Results: A total of 42 pre-irradiated patients with RT2 were matched to 42 pre-irradiated controls without RT2. RT2 improved the median PFS [21.0 (CI: 15.7–28.7) vs. 12.0 (CI: 8.1–21.0) months] and OS [31.5 (CI: 27.6–64.8) vs. 20.0 (CI: 14.0–36.7) months]. Concerning long-term survival after ten years, RT2 only lead to small improvements in OS [8% (CI: 1.4–45.3) vs. 0%]. RT2 improved survival most without (re)-resection [PFS: 17.5 (CI: 9.7–41.5) vs. 8.0 (CI: 6.6–12.2)/OS: 31.5 (CI: 27.6–NA) vs. 13.3 (CI: 8.1–20.1) months]. In the RT-naïve patients, CSI at recurrence improved their median PFS [25.0 (CI: 16.8–60.6) vs. 6.6 (CI: 1.5–NA) months] and OS [40.2 (CI: 18.7–NA) vs. 12.4 (CI: 4.4–NA) months]. Conclusions: RT2 could improve the median survival in a matched cohort but offered little benefit regarding long-term survival. In RT-naïve patients, CSI greatly improved their median and long-term survival. [ABSTRACT FROM AUTHOR]

Simple Summary: The effects of reduced prescription doses on normal tissue toxicity in the treatment of non-Hodgkin lymphomas of the neck/thorax region remain unclear. Acute side effects, which already occur at low organ doses, can only be described to a limited extent by the models given in the literature. Nonetheless, the knowledge about these dose–response relationships is particularly important to predict an acute response in normal tissue adequately. Considering a robust normal tissue toxicity model, dose prescriptions and treatment plans can be optimized to increase the treatment quality and, thus, the outcome for the patient. This biophysical study aimed to determine fitting parameters for the Lyman–Kutcher–Burman (LKB) dose–response model for normal tissue complication probability (NTCP) calculations of acute side effects and to investigate the impact of reduced radiation doses on the probability of their occurrence in supradiaphragmatic non-Hodgkin lymphoma (NHL) irradiation. A cohort of 114 patients with NHL in the cervicothoracic region, treated between 2015 and 2021 at the University Hospitals of Münster, Hamburg, and Essen, with involved site radiation therapy (ISRT), were included. Among them, 68 patients with aggressive NHL (a-NHL) received consolidative radiation therapy with 24–54 Gy following (R-)CHOP chemotherapy. Additionally, 46 patients with indolent NHL (i-NHL) underwent radiotherapy with 22.5–45.0 Gy. Two treatment plans were prospectively created for each patient (a-NHL: 30.0/40.0 Gy; i-NHL: 24.0/30.0 Gy). NTCP were then calculated using the optimized LKB model. The adapted dose–response models properly predicted the patient's probability of developing acute side effects when receiving doses ≤ 50 Gy. In addition, it was shown that reduced radiation doses can influence the NTCP of acute side effects depending on the aggressiveness of NHL significantly. This study provided a foundation to prospectively assess the probability of adverse side effects among today's reduced radiation doses in the treatment of NHL. [ABSTRACT FROM AUTHOR]

Background: Proton beam therapy (PBT) is being increas16ingly used to treat residual craniopharyngioma (CP) after hypothalamus-sparing surgery. Compared to photon-based radiation therapy (XRT) with PBT, less irradiation in the penumbra reduces the scattered dose to critical organs neighboring but outside the area of treatment, minimizing the risk of sequelae. Patients and methods: Between 2007 and 2019, 99 of 290 (34%) childhood-onset CP patients recruited in KRANIOPHARYNGEOM 2007 received external radiation therapy (RT) (65% PBT, 35% XRT). Outcome was analyzed in terms of survival, endocrinological and anthropometric parameters (BMI and height SDS), quality of life (QoL using PEDQOL), and functional capacity (FMH) with special regard to irradiation technique. Results: PBT became predominant (used in 43% and 72% of all irradiated patients registered within the first and second halves of the recruitment period, between 2008 and 2013 and 2013 and 2018, respectively). Five-year event-free survival rates after PBT or XRT were comparable (92% ± 4% vs. 91% ± 4%, p = 0.42) and higher than for the whole cohort since diagnosis, including non-RT patients (37% ± 4%). Radiation doses to the hypothalamus and pituitary did not differ between PBT and XRT. Endocrine deficits due to disturbances of the hypothalamic-pituitary axis (HPA) were already common before irradiation. During the first 5 years after CP diagnosis/RT, no differences between PBT, XRT, and non-RT CP patients concerning functional capacity and anthropometric parameters have been obtained. Only for the PEDQOL domain "physical function", parental-assessed QoL was lower 12 months after PBT versus XRT or non-RT patients. Conclusion: QoL, functional capacity, degree of obesity, and endocrinopathy varied over time from diagnosis, but by 5 years, there was no significant difference between PBT and XRT upfront or delayed, nor was there any compromise in historic survival rates, which remained high >90%. RT of any type is extremely effective at stabilizing disease after hypothalamic-sparing surgery. The purported specific benefits of PBT-reducing sequelae are not proven in this study where the organ of critical interest is itself diseased, increasing an urgent need to better address and treat the tumor-induced endocrine harm from diagnosis in dedicated pituitary services. Other hypothesized benefits of PBT versus XRT on vascular events and secondary cancers await longer comparison. [ABSTRACT FROM AUTHOR]

Background: Margin status following surgery in children, adolescents, and young adults with soft tissue sarcomas is controversial and has been defined differently by various specialties, with definitions changing over time and by cooperative group. The International Soft Tissue Sarcoma Consortium (INSTRuCT) is a collaboration of the Children's Oncology Group (COG) Soft Tissue Sarcoma Committee, European pediatric Soft Tissue sarcoma Study Group (EpSSG), and the European Cooperative Weichteilsarkom Studiengruppe (CWS) devoted to improving patient outcomes by pooling and mining cooperative group clinical trial data. Methods: The INSTRuCT non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) working group aimed to develop international harmonized recommendations regarding surgical margin assessment and definitions in children and adolescents with soft tissue tumors. Results and Conclusion: This review addresses accepted principles and areas of controversy, including the perspectives of surgeons, pathologists, radiation oncologists, and pediatric oncologists, to develop a framework for building common guidelines for future research. [ABSTRACT FROM AUTHOR]

• Multimodal treatment of children with AT/RT. • Complex therapy in very young children and infants with high-risk tumors. • European guideline regarding radiotherapy in AT/RT. • Challenges and strategies in the clinical management of patients with AT/RT. Treatment of patients with atypical teratoid/rhabdoid (AT/RT) is challenging, especially when very young (below the age of three years). Radiotherapy (RT) is part of a complex trimodality therapy. The purpose of this guideline is to provide appropriate recommendations for RT in the clinical management of patients not enrolled in clinical trials. Nine European experts were nominated to form a European Society for Radiotherapy and Oncology (ESTRO) guideline committee. A systematic literature search was conducted in PubMed/MEDLINE and Web of Science. They discussed and analyzed the evidence concerning the role of RT in the clinical management of AT/RT. Recommendations on diagnostic imaging, therapeutic principles, RT considerations regarding timing, dose, techniques, target volume definitions, dose constraints of radiation-sensitive organs at risk, concomitant chemotherapy, and follow-up were considered. Treating children with AT/RT within the framework of prospective trials or prospective registries is of utmost importance. The present guideline summarizes the evidence and clinical-based recommendations for RT in patients with AT/RT. Prospective clinical trials and international, large registries evaluating modern treatment approaches will contribute to a better understanding of the best treatment for these children in future. [ABSTRACT FROM AUTHOR]

Background: The benefit of adjuvant therapy in synovial sarcoma (SS) treatment is under debate. Long-term follow-up data are missing. Methods: SS patients treated in the consecutive trials CWS-81, CWS-86, CWS-91, CWS-96, CWS-2002-P, and the SoTiSaR-registry till 2013 were analyzed. Results: Median age of 185 patients was 13.9 years (0.1–56)—with median follow-up of 7.4 years for 163 survivors. Most tumors (76%) were located in extremities. Size was < 3 cm in 58 (31%), 3–5 cm in 59 (32%), 5–10 cm in 42 (23%), and > 10 cm in 13 (7%) (13 missing). In 84 (45%) tumors, first excision was complete (R0 corresponding to IRS-I-group) and in 101 (55%) marginal (R1 corresponding to IRS-II-group). In a subsequent surgical intervention during chemotherapy, R0-status was accomplished in 23 additional IRS-II-group patients with secondary surgery. Radiotherapy was administered to 135 (73%), thereof 62 with R0-status and 67 R1-status (6 missing information). Adjuvant chemotherapy was administered to all but six patients. 5-year event-free (EFS) and overall survival (OS) was 82.9% ± 5.7 (95%CI) and 92.5% ± 3.9. Local and metastatic relapse-free survival was 91.3% ± 4.3 and 92.3% ± 4.1 at 5 years, respectively. In the multivariate analysis, tumor size and no chemotherapy were independently associated with EFS. Size and site were associated with OS. In a detailed analysis of local and metastatic events, tumor size was associated with an independent risk for developing metastases. No independent factor for suffering local recurrence could be identified. Discussion: Omission of chemotherapy in a non-stratified way seems not justified. Size governs survival due to high linear association with risk of suffering metastatic recurrence in a granular classification. [ABSTRACT FROM AUTHOR]

Pediatric ependymomas comprise biologically distinct tumor entities with different (epi)genetics, age distribution and localization, as well as a different prognosis. Regarding risk stratification within these biologically defined entities, histopathological features still seem to be relevant. The mainstay of treatment is gross total resection (GTR) if possible, achieved with intraoperative monitoring and neuronavigation—and if necessary second surgery—followed by adjuvant radiation therapy. However, there is growing evidence that some ependymal tumors may be cured by surgery alone, while others relapse despite adjuvant treatment. To date, the role of chemotherapy is not clear. Current therapy achieves reasonable survival rates for the majority of ependymoma patients. The next challenge is to go beyond initial tumor control and use risk-adapted therapy to reduce secondary effect and therapy-induced morbidity for low-risk patients and to intensify treatment for high-risk patients. With identification of specific alterations, targeted therapy may represent an option for individualized treatment modalities in the future. [ABSTRACT FROM AUTHOR]

• Across SIOPE-affiliated centers, disparities in survival and late toxicity are a reality. • Survey-based, 25 items related to the RT organization & equipment per center were scored. • Pediatric radiotherapy resources were mapped across 121/246 centers in 31/35 countries. • Relevant variations in organization of the RT process and equipment were observed. • Centers in countries with a high-income and higher health development index scored better. To reduce inequalities among SIOPE-affiliated countries, standard and optional levels to deliver 'Good Clinical Practice' compliant treatment in pediatric radiation oncology have been published. The aim of this project was to map the availability of pediatric radiotherapy resources across SIOPE-affiliated radiotherapy departments. An online survey with 34 questions was distributed to 246 radiotherapy departments across 35 SIOPE-affiliated countries. In addition to demographic data, 15 general items related to the organization of the radiotherapy process, and 10 radiotherapy-specific items were defined. For each of the 25 items, sum scores were calculated per center and country. Mann-Whitney U tests were used to analyze associations. Between March-June 2019, 121 departments (49 %) out of 31 countries (89 %) completed the survey. At center level, involvement of core disciplines in tumor boards (28 %), and integration of dedicated pediatric radiation therapy technologists (24 %) are limited, while rare & complex brachytherapy procedures are performed in many centers (23 %). For general and radiotherapy-specific items respectively, a relevant variation of sum scores was observed across countries (Δ general : ≤10 points; Δ RT_specific : ≤5 points) and among centers within a country (Δ general : ≤9 points; Δ RT_specific : ≤6 points). Sum scores for general and radiotherapy-specific items were higher in countries with a high-income (p < 0.01) and higher health development index (p < 0.01). A larger annual number of irradiated pediatric patients was associated with higher sum scores for general items (p < 0.01). This survey demonstrates the disparities in organization of pediatric radiotherapy departments between SIOPE-affiliated countries and centers within the same country. Investment is needed to reduce inequalities in pediatric radiotherapy care. [ABSTRACT FROM AUTHOR]

First‐line treatment of pediatric low‐grade glioma using surgery, radio‐ or chemotherapy fails in a relevant proportion of patients. We analyzed efficacy of subsequent surgical and nonsurgical therapies of the German cohort of the SIOP‐LGG 2004 study (2004‐2012, 1558 registered patients; median age at diagnosis 7.6 years, median observation time 9.2 years, overall survival 98%/96% at 5/10 years, 15% neurofibromatosis type 1 [NF1]). During follow‐up, 1078/1558 patients remained observed without (n = 217), with 1 (n = 707), 2 (n = 124) or 3 to 6 (n = 30) tumor volume reductions; 480/1558 had 1 (n = 332), 2 (n = 80), 3 or more (n = 68) nonsurgical treatment‐lines, accompanied by up to 4 tumor‐reductive surgeries in 215/480; 265/480 patients never underwent any neurosurgical tumor volume reduction (163/265 optic pathway glioma). Patients with progressing tumors after first‐line adjuvant treatment were at increased risk of suffering further progressions. Risk factors were young age (<1 year) at start of treatment, tumor dissemination or progression within 18 months after start of chemotherapy. Progression‐free survival rates declined with subsequent treatment‐lines, yet remaining higher for patients with NF1. In non‐NF1‐associated tumors, vinblastine monotherapy vs platinum‐based chemotherapy was noticeably less effective when used as second‐line treatment. Yet, for the entire cohort, results did not favor a certain sequence of specific treatment options. Rather, all can be aligned as a portfolio of choices which need careful balancing of risks and benefits. Future molecular data may predict long‐term tumor biology. What's new? For some patients with pediatric low‐grade glioma, first‐line treatment isn't enough. Here, the authors evaluated the effectiveness of various second‐line strategies, including surgical and non‐surgical therapies, in a German cohort. Risk factors for tumor progression included age under 1 year at diagnosis, early treatment failure, and tumor dissemination. Over the entire cohort, the results did not clearly support one specific treatment strategy as the best choice, although platinum‐based therapy performed better than vinblastine in non‐NF1 tumors. This is the first long term analysis of comprehensive treatment strategies in recurrent tumors in a population‐based, prospectively registered pediatric low‐grade glioma cohort. [ABSTRACT FROM AUTHOR]

Reports on pediatric low‐grade glioma (LGG) of the caudal brainstem are retrospective with heterogeneous cohorts, variable treatments and inconsistent outcome data. We analyzed their natural history and asked whether brainstem location proved unfavorable for survival within the framework of the comprehensive SIOP‐LGG 2004 management strategy. Within the prospectively registered, population‐based German SIOP‐LGG 2004 cohort 116 patients (age 0.2–16.5 years, 10% Neurofibromatosis NF1) were diagnosed with LGG of the pons (27%) and medulla oblongata (73%). After biopsy (23%), variable resection (63%) or radiologic diagnosis only (14%), 59 patients received no adjuvant treatment. Radiologic progression or severe neurologic symptoms prompted chemo‐ (n = 39) or radiotherapy (n = 18). After further progression (28/57), salvage treatments included multiple treatment lines for 12/28 patients. Five‐years event‐free survival dropped to 0.40, while 5‐years overall survival was 0.95 (median observation time 6.8 years). Higher extent of resection yielded lower progression rate (p = 0.001), but at a cost of 21/100 patients suffering from new postsurgical complications including respiratory insufficiency. Central review confirmed pilocytic astrocytoma (56%), diffuse astrocytoma (8%) or glioneuronal histology (16%) (others 4%, no histology 17%). Malignant evolution was documented in five patients associated with Histone3 mutation in 2/5. Our treatment algorithm conveyed high overall survival for pediatric brainstem LGG. Extensive neurosurgical resection did increase additional postoperative neurologic deficits but not overall survival in this often‐chronic disease. More than half of all patients can be safely followed by observation, while multimodal adjuvant treatment can control progressive tumors. Molecular assessment should confirm low‐grade diagnosis and may detect patterns prognostic for malignant evolution. What's new? Outcome studies for pediatric low‐grade gliomas (LGG) of the brainstem have generally been small and of low quality, making it difficult to determine prognosis. In this prospective, multicenter study, the authors developed a detailed description of the natural history, treatment response, and prognostic factors associated with favorable survival when a comprehensive treatment strategy was used. This treatment algorithm resulted in high overall survival for pediatric brainstem LGG. The study also emphasizes the importance of the predictive value of molecular patterns, as malignant evolution can occur even in low‐grade tumors. [ABSTRACT FROM AUTHOR]

Background: Local treatment of pelvic Ewing's sarcoma may be challenging, and intergroup studies have focused on improving systemic treatments rather than prospectively evaluating aspects of local tumor control. The Euro-EWING99 trial provided a substantial number of patients with localized pelvic tumors treated with the same chemotherapy protocol. Because local control included surgical resection, radiation therapy, or a combination of both, we wanted to investigate local control and survival with respect to the local modality in this study cohort.Questions/purposes: (1) Do patients with localized sacral tumors have a lower risk of local recurrence and higher survival compared with patients with localized tumors of the innominate bones? (2) Is the local treatment modality associated with local control and survival in patients with sacral and nonsacral tumors? (3) Which local tumor- and treatment-related factors, such as response to neoadjuvant chemotherapy, institution where the biopsy was performed, and surgical complications, are associated with local recurrence and patient survival in nonsacral tumors? (4) Which factors, such as persistent extraosseous tumor growth after chemotherapy or extent of bony resection, are independently associated with overall survival in patients with bone tumors undergoing surgical treatment?Methods: Between 1998 and 2009, 1411 patients with previously untreated, histologically confirmed Ewing's sarcoma were registered in the German Society for Pediatric Oncology and Hematology Ewing's sarcoma database and treated in the Euro-EWING99 trial. In all, 24% (339 of 1411) of these patients presented with a pelvic primary sarcoma, 47% (159 of 339) of which had macroscopic metastases at diagnosis and were excluded from this analysis. The data from the remaining 180 patients were reviewed retrospectively, based on follow-up data as of July 2016. The median (range) follow-up was 54 months (5 to 191) for all patients and 84 months (11 to 191) for surviving patients. The study endpoints were overall survival, local recurrence and event-free survival probability, which were calculated with the Kaplan-Meier method and compared using the log-rank test. Hazard ratios (HRs) with their respective 95% CIs were estimated in a multivariate Cox regression model.Results: Sacral tumors were associated with a reduced probability of local recurrence (12% [95% CI 1 to 22] versus 28% [95% CI 20 to 36] at 5 years, p = 0.032), a higher event-free survival probability (66% [95% CI 51 to 81] versus 50% [95% CI 41 to 58] at 5 years, p = 0.026) and a higher overall survival probability (72% [95% CI 57 to 87] versus 56% [95% CI 47 to 64] at 5 years, p = 0.025) compared with nonsacral tumors. With the numbers available, we found no differences between patients with sacral tumors who underwent definitive radiotherapy and those who underwent combined surgery and radiotherapy in terms of local recurrence (17% [95% CI 0 to 34] versus 0% [95% CI 0 to 20] at 5 years, p = 0.125) and overall survival probability (73% [95% CI 52 to 94] versus 78% [95% CI 56 to 99] at 5 years, p = 0.764). In nonsacral tumors, combined local treatment was associated with a lower local recurrence probability (14% [95% CI 5 to 23] versus 33% [95% CI 19 to 47] at 5 years, p = 0.015) and a higher overall survival probability (72% [95% CI 61 to 83] versus 47% [95% CI 33 to 62] at 5 years, p = 0.024) compared with surgery alone. Even in a subgroup of patients with wide surgical margins and a good histologic response to induction treatment, the combined local treatment was associated with a higher overall survival probability (87% [95% CI 74 to 100] versus 51% [95% CI 33 to 69] at 5 years, p = 0.009), compared with surgery alone.A poor histologic response to induction chemotherapy in nonsacral tumors (39% [95% CI 19 to 59] versus 64% [95% CI 52 to 76] at 5 years, p = 0.014) and the development of surgical complications after tumor resection (35% [95% CI 11 to 59] versus 68% [95% CI 58 to 78] at 5 years, p = 0.004) were associated with a lower overall survival probability in nonsacral tumors, while a tumor biopsy performed at the same institution where the tumor resection was performed was associated with lower local recurrence probability (14% [95% CI 4 to 24] versus 32% [95% CI 16 to 48] at 5 years, p = 0.035), respectively.In patients with bone tumors who underwent surgical treatment, we found that after controlling for tumor localization in the pelvis, tumor volume, and surgical margin status, patients who did not undergo complete (defined as a Type I/II resection for iliac bone tumors, a Type II/III resection for pubic bone and ischium tumors and a Type I/II/III resection for tumors involving the acetabulum, according to the Enneking classification) removal of the affected bone (HR 5.04 [95% CI 2.07 to 12.24]; p < 0.001), patients with a poor histologic response to induction chemotherapy (HR 3.72 [95% CI 1.51 to 9.21]; p = 0.004), and patients who did not receive additional radiotherapy (HR 4.34 [95% CI 1.71 to 11.05]; p = 0.002) had a higher risk of death. The analysis suggested that the same might be the case in patients with a persistent extraosseous tumor extension after induction chemotherapy (HR 4.61 [95% CI 1.03 to 20.67]; p = 0.046), although the wide CIs pointing at a possible sparse-data bias precluded any definitive conclusions.Conclusion: Patients with sacral Ewing's sarcoma appear to have a lower probability for local recurrence and a higher overall survival probability compared with patients with tumors of the innominate bones. Our results seem to support a recent recommendation of the Scandinavian Sarcoma Group to locally treat most sacral Ewing's sarcomas with definitive radiotherapy. Combined surgical resection and radiotherapy appear to be associated with a higher overall survival probability in nonsacral tumors compared with surgery alone, even in patients with a wide resection and a good histologic response to neoadjuvant chemotherapy. Complete removal of the involved bone, as defined above, in patients with nonsacral tumors may be associated with a decreased likelihood of local recurrence and improved overall survival. Persistent extraosseous tumor growth after induction treatment in patients with nonsacral bone tumors undergoing surgical treatment might be an important indicator of poorer overall survival probability, but the possibility of sparse-data bias in our cohort means that this factor should first be validated in future studies.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Disparities in survival and long-term side-effects from paediatric cancer are observed across European Society for Paediatric Oncology (SIOPE)–affiliated countries. The Joint Action on Rare Cancers (JARC) is a project supported by the European Union and member states aiming to formulate recommendations on rare cancers, including paediatric malignancies, to reduce inequalities and to improve health outcomes. Most paediatric cancers are treated by a combination of systemic agents, surgery and/or radiotherapy. Radiotherapy for children is becoming increasingly complex because of the growing availability of new modalities and techniques and the evolution in molecular biology. These added challenges have the potential to enhance disparities in survival and side-effects between countries, but also among centres in the same country. To tackle radiotherapy-related inequalities, representatives of SIOPE, European SocieTy for Radiotherapy and Oncology, Paediatric Radiation Oncology Society and Childhood Cancer International–Europe defined 'standard' and 'optional' levels to deliver Good Clinical Practice–compliant treatment in paediatric radiation oncology with a focus on patient-related care, education and training. In addition, more than 250 paediatric radiotherapy centres across the SIOPE-affiliated countries have been mapped. For a better understanding of resources in paediatric radiotherapy, JARC representatives are working on an online survey for paediatric radiation oncologists of each centre in SIOPE-affiliated countries. The outcome of this survey will give an insight into the strengths and weaknesses of paediatric radiotherapy across SIOPE-affiliated countries and can be relevant for European Reference Networks in terms of collaboration pathways and referrals in paediatric radiotherapy. • Across European Society for Paediatric Oncology–affiliated countries, disparities in childhood cancer survival are a fact. • Radiotherapy for children is becoming increasingly complex. • The Joint Action on Rare Cancers aims to formulate appropriate recommendations to reduce inequalities. • Recommendations focus on patient care, education and training, and clinical research. [ABSTRACT FROM AUTHOR]

Purpose: Conventional techniques (3D-CRT) for craniospinal irradiation (CSI) are still widely used. Modern techniques (IMRT, VMAT, TomoTherapy®, proton pencil beam scanning [PBS]) are applied in a limited number of centers. For a 14-year-old patient, we aimed to compare dose distributions of five CSI techniques applied across Europe and generated according to the participating institute protocols, therefore representing daily practice. Material and methods: A multicenter (n=15) dosimetric analysis of five different techniques for CSI (3D-CRT, IMRT, VMAT, TomoTherapy®, PBS; 3 centers per technique) was performed using the same patient data, set of delineations and dose prescription (36.0/1.8 Gy). Different treatment plans were optimized based on the same planning target volume margin. All participating institutes returned their best treatment plan applicable in clinic. Results: The modern radiotherapy techniques investigated resulted in superior conformity/homogeneity- indices (CI/HI), particularly in the spinal part of the target (CI: 3D-CRT:0.3 vs. modern:0.6; HI: 3D-CRT:0.2 vs. modern:0.1), and demonstrated a decreased dose to the thyroid, heart, esophagus and pancreas. Dose reductions of >10.0 Gy were observed with PBS compared to modern photon techniques for parotid glands, thyroid and pancreas. Following this technique, a wide range in dosimetry among centers using the same technique was observed (e.g., thyroid mean dose: VMAT: 5.6-24.6 Gy; PBS: 0.3-10.1 Gy). Conclusions: The investigated modern radiotherapy techniques demonstrate superior dosimetric results compared to 3D-CRT. The lowest mean dose for organs at risk is obtained with proton therapy. However, for a large number of organs ranges in mean doses were wide and overlapping between techniques making it difficult to recommend one radiotherapy technique over another. [ABSTRACT FROM AUTHOR]

Background The registry for the evaluation of side effects after radiotherapy in childhood and adolescence (RiSK) was established to prospectively characterize radiation-associated side effects. The purpose of this analysis was to characterize side effects after radiotherapy to the head and neck in children and adolescents. Methods Radiation doses have been collected across Germany since 2001. Acute and late side effects were characterized. Results Until January 2010, 133 patients (median age, 12.7 years) were recruited who had received radiotherapy to the salivary glands. Toxicity evaluation was available for 114 patients (median follow-up, 2.9 years). Acute and late toxicity significantly depended on the maximum radiation dose to the salivary glands. An increase of the mean value of maximum dose of 1 Gray (Gy) to the submandibular glands resulted in an odds ratio of 1.04 (range, 1.00-1.08; p = .039) for acute toxicities of the salivary glands and 1.08 (range, 1.03-1.13; p = .001) for acute mucosal toxicities. Conclusion These data can be used for an individual risk assessment in pediatric head and neck radiotherapy. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1137-1141, 2015 [ABSTRACT FROM AUTHOR]

Simple Summary: Multimodal treatment of nasopharyngeal carcinoma (NPC) in children and young adults with induction chemotherapy, followed by radiochemotherapy and interferon-β (IFN-β) maintenance, has been successfully applied in studies NPC-91 and NPC-2003 of the German Society of Pediatric Oncology and Hematology (GPOH). We, here, present updated survival rates of the NPC-2003 study cohort after longer follow-up and include 21 additional patients recruited after closure of the study and treated as per the NPC-2003 study protocol (interim cohort) in our survival analysis. Survival rates remain high after extended follow-up and in the larger cohort with EFS and OS of 94% and 97%, respectively, reinforcing the high antitumor efficacy of this multimodal treatment concept. Seven patients with CR after induction therapy received a reduced radiation dose of 54 Gy, and none of them relapsed. Thus, the reduction of radiation dose seems feasible and has the potential to reduce treatment-related late effects in this vulnerable population. Nasopharyngeal carcinoma (NPC) in children and young adults has been treated within two consecutive prospective trials in Germany, the NPC-91 and the NPC-2003 study of the German Society of Pediatric Oncology and Hematology (GPOH). In these studies, multimodal treatment with induction chemotherapy, followed by radio (chemo)therapy and interferon-beta maintenance, yielded promising survival rates even after adapting total radiation doses to tumor response. The outcome of 45 patients in the NPC-2003 study was reassessed after a median follow-up of 85 months. In addition, we analyzed 21 further patients after closure of the NPC-2003 study, recruited between 2011 and 2017, and treated as per the NPC-2003 study protocol. The EFS and OS of 66 patients with locoregionally advanced NPC were 93.6% and 96.7%, respectively, after a median follow-up of 73 months. Seven patients with CR after induction therapy received a reduced radiation dose of 54 Gy; none relapsed. In young patients with advanced locoregional NPC, excellent long-term survival rates can be achieved by multimodal treatment, including interferon-beta. Radiation doses may be reduced in patients with complete remission after induction chemotherapy and may limit radiogenic late effects. [ABSTRACT FROM AUTHOR]

Simple Summary: Medulloblastoma is the commonest malignant brain tumour of childhood. Disease relapse following maximal multi-modal therapy including upfront craniospinal irradiation (CSI) is almost always fatal and occurs in approximately 30% of patients. Importantly, patients rarely die of other causes, and consequently relapsed medulloblastoma (rMB) accounts for 10% of all childhood cancer deaths. There is a variety of life-prolonging treatment options at relapse including neurosurgery, re-irradiation, early-phase trials, and chemotherapy. Here, we summarise best practice for investigations including re-biopsy and molecular characterisation of rMB, treatment decision making, and available treatment options. We also highlight advances in the understanding of rMB disease biology and prognostic factors, and look towards future developments such as targeted therapies, liquid biopsies and disease modelling strategies to improve outcomes in this area of unmet clinical need. Relapsed medulloblastoma (rMB) accounts for a considerable, and disproportionate amount of childhood cancer deaths. Recent advances have gone someway to characterising disease biology at relapse including second malignancies that often cannot be distinguished from relapse on imaging alone. Furthermore, there are now multiple international early-phase trials exploring drug–target matches across a range of high-risk/relapsed paediatric tumours. Despite these advances, treatment at relapse in pre-irradiated patients is typically non-curative and focuses on providing life-prolonging and symptom-modifying care that is tailored to the needs and wishes of the individual and their family. Here, we describe the current understanding of prognostic factors at disease relapse such as principal molecular group, adverse molecular biology, and timing of relapse. We provide an overview of the clinical diagnostic process including signs and symptoms, staging investigations, and molecular pathology, followed by a summary of treatment modalities and considerations. Finally, we summarise future directions to progress understanding of treatment resistance and the biological mechanisms underpinning early therapy-refractory and relapsed disease. These initiatives include development of comprehensive and collaborative molecular profiling approaches at relapse, liquid biopsies such as cerebrospinal fluid (CSF) as a biomarker of minimal residual disease (MRD), modelling strategies, and the use of primary tumour material for real-time drug screening approaches. [ABSTRACT FROM AUTHOR]

Background: Vacuum-assisted bite-block immobilization of the head is a reliable technique for reproducible precise head positioning as used for proton radiation in adults. We report preliminary experience using deep propofol sedation without an artificial airway in children undergoing proton radiation of cranial tumors requiring vacuum-assisted bite-block immobilization. Methods: Sedation was started with a bolus of i.v. midazolam followed by repeated small boluses of propofol as required to tolerate bite-block insertion and patient positioning. Sedation was maintained by continuous propofol infusion until removal of the bite block. Oxygen was administered by a nasal cannula. SpO2, endtidal CO2 taken at the nose and respiratory adverse events such as coughing, bucking, airway obstruction, regurgitation or aspiration were recorded. Data are mean ± sd. Results: Ten children aged 2.6 ± 0.8 years were treated to date. For each child, cumulative 26.7 ± 1.9 radiation fractions were administered. Propofol dose administered for induction, bite-block insertion and patient positioning was 3.9 ± 0.5 mg·kg−1. Time from insertion to removal of the bite block lasted 48.3 ± 6.2 min. Endtidal CO2 values were 5.6 ± 0.8 kPa (43 ± 7 mmHg) and SpO2 values were 98.3 ± 1.9% with spontaneous breathing, supplemental oxygen and bite block inserted. No respiratory adverse events occurred during the 267 sedation procedures performed. Conclusion: Deep propofol sedation without the use of an artificial airway is an interesting technique for vacuum-assisted bite-block immobilization in young children undergoing precise radiation therapy of cranial tumors. However, simultaneous individual anesthetic challenges require pediatric anesthesiologists highly experienced with the pediatric airway, clinical alertness and closed monitoring. [ABSTRACT FROM AUTHOR]

Proton beam therapy is a highly conformal form of radiation therapy, which currently represents an important therapeutic component in multidisciplinary management in paediatric oncology. The precise adjustability of protons results in a reduction of radiation-related long-term side-effects and secondary malignancy induction, which is of particular importance for the quality of life. Proton irradiation has been shown to offer significant advantages over conventional photon-based radiotherapy, although the biological effectiveness of both irradiation modalities is comparable. This review evaluates current data from clinical and dosimetric studies on the treatment of tumours of the central nervous system, soft tissue and bone sarcomas of the head and neck region, paraspinal or pelvic region, and retinoblastoma. To date, the clinical results of irradiating childhood tumours with high-precision proton therapy are promising both with regard to tumour cure and the reduction of adverse events. Modern proton therapy techniques such as pencil beam scanning and intensity modulation are increasingly established modern facilities. However, further investigations with larger patient cohorts and longer follow-up periods are required, in order to be able to have clear evidence on clinical benefits. [ABSTRACT FROM AUTHOR]

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare malignancy of the central nervous system in young children with a dismal prognosis. Prognostic markers have been extensively investigated but have not been validated. The role of radiation therapy (RT) remains controversial. We evaluated the impact of RT as part of multimodality treatment by analyzing data of a European AT/RT cohort. We retrospectively analyzed data of the European Registry for Rhabdoid Tumors and its precursors. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Potential impact of prognostic factors was analyzed using univariable and multivariable Cox regression analyses with RT as a time-dependent factor. Data of 186 children (118 male, 68 female) treated from 1990 to 2016 were evaluable. The median age at diagnosis was 1.57 years (range, 0.01-26.70 years); 47% (87/186) of the patients were under the age of 18 months. Sixty-nine percent (128/186) received RT (focal RT, n = 93; craniospinal treatment with local boost, n = 34; spinal irradiation, n = 1). The median follow-up duration of the entire cohort was 1.73 years (range, 0.06-20.11 years). The estimated PFS and OS rates were 48% (95% CI, 41%-55%) and 72% (95% CI, 65%-78%) at 1 year and 33% (95% CI, 26%-40%) and 49% (95% CI, 41%-56%) at 2 years, respectively. On multivariable analysis, RT was an independent significant prognostic factor for PFS (hazard ratio, 0.45; 95% CI, 0.27-0.75; P =.002) and OS (hazard ratio, 0.54; 95% CI, 0.32-0.93; P =.025). This analysis confirms the relevance of local therapies. RT was an independent prognostic factor for outcomes in children experiencing AT/RT. However, long-term sequelae have to be carefully evaluated and considered given the young age at time of RT. [ABSTRACT FROM AUTHOR]

Background: PRIMO is a dose verification system based on the general-purpose Monte Carlo radiation transport code PENELOPE, which implements an accurate physics model of the interaction cross sections and the radiation transport process but with low computational efficiency as compared with fast Monte Carlo codes. One of these fast Monte Carlo codes is the Dose Planning Method (DPM). The purpose of this work is to describe the adaptation of DPM as an alternative PRIMO computation engine, to validate its performance against PENELOPE and to validate it for some specific cases.Methods: DPM was parallelized and modified to perform radiation transport in quadric geometries, which are used to describe linacs, thus allowing the simulation of dynamic treatments. To benchmark the new code versus PENELOPE, both in terms of accuracy of results and simulation time, several tests were performed, namely, irradiation of a multi-layer phantom, irradiation of a water phantom using a collimating pattern defined by the multileaf collimator (MLC), and four clinical cases. The gamma index, with passing criteria of 1 mm/1%, was used to compare the absorbed dose distributions. Clinical cases were compared using a 3-D gamma analysis.Results: The percentage of voxels passing the gamma criteria always exceeded 99% for the phantom cases, with the exception of the transport through air, for which dose differences between DPM and PENELOPE were as large as 24%. The corresponding percentage for the clinical cases was larger than 99%. The speedup factor between DPM and PENELOPE ranged from 2.5 ×, for the simulation of the radiation transport through a MLC and the subsequent dose estimation in a water phantom, up to 11.8 × for a lung treatment. A further increase of the computational speed, up to 25 ×, can be obtained in the clinical cases when a voxel size of (2.5 mm)3 is used.Conclusions: DPM has been incorporated as an efficient and accurate Monte Carlo engine for dose estimation in PRIMO. It allows the concatenated simulation of the patient-dependent part of the linac and the patient geometry in static and dynamic treatments. The discrepancy observed between DPM and PENELOPE, which is due to an artifact of the cross section interpolation algorithm for low energy electrons in air, does not affect the results in other materials. [ABSTRACT FROM AUTHOR]

• No guidelines for the optimal use of paediatric radiotherapy facilities during a shortage. • Recommendations for the optimal use of paediatric radiotherapy facilities are presented. • This guideline has applications in low and middle income countries with limited resources. To derive evidence-based recommendations for the optimal utilisation of resources during unexpected shortage of radiotherapy capacity. We have undertaken a rapid review of published literature on the role of radiotherapy in the multimodality treatment of paediatric cancers governing the European practise of paediatric radiotherapy. The derived data has been discussed with expert paediatric radiation oncologists to derive a hierarchy of recommendations. The general recommendations to mitigate the potential detriment of an unexpected shortage of radiotherapy facilities include: (1) maintain current standards of care as long as possible (2) refer to another specialist paediatric radiotherapy department with similar level of expertise (3) prioritise use of existing radiotherapy resources to treat patients with tumours where radiotherapy has the most effect on clinical outcome (4) use chemotherapy to defer the start of radiotherapy where timing of radiotherapy is not expected to be detrimental (5) active surveillance for low-grade tumours if appropriate and (6) consider iso-effective hypofractionated radiotherapy regimens only for selected patients with predicted poor prognosis. The effectiveness of radiotherapy and recommendations for prioritisation of its use for common and challenging paediatric tumours are discussed. This review provides evidence-based treatment recommendations during unexpected shortage of paediatric radiotherapy facilities. It has wider applications for the optimal utilisation of facilities, to improve clinical outcome in low- and middle-income countries, where limited resources continue to be a challenge. [ABSTRACT FROM AUTHOR]

Inhomogeneities in radiotherapy dose distributions covering the vertebrae in children can produce long-term spinal problems, including kyphosis, lordosis, scoliosis, and hypoplasia. In the published literature, many often interrelated variables have been reported to affect the extent of potential radiotherapy damage to the spine. Articles published in the 2D and 3D radiotherapy era instructed radiation oncologists to avoid dose inhomogeneity over growing vertebrae. However, in the present era of highly conformal radiotherapy, steep dose gradients over at-risk structures can be generated and thus less harm is caused to patients. In this report, paediatric radiation oncologists from leading centres in 11 European countries have produced recommendations on how to approach dose coverage for target volumes that are adjacent to vertebrae to minimise the risk of long-term spinal problems. Based on available information, it is advised that homogeneous vertebral radiotherapy doses should be delivered in children who have not yet finished the pubertal growth spurt. If dose fall-off within vertebrae cannot be avoided, acceptable dose gradients for different age groups are detailed here. Vertebral delineation should include all primary ossification centres and growth plates, and therefore include at least the vertebral body and arch. For partial spinal radiotherapy, the number of irradiated vertebrae should be restricted as much as achievable, particularly at the thoracic level in young children (<6 years old). There is a need for multicentre research on vertebral radiotherapy dose distributions for children, but until more valid data become available, these recommendations can provide a basis for daily practice for radiation oncologists who have patients that require vertebral radiotherapy. [ABSTRACT FROM AUTHOR]

The European Society for Paediatric Oncology (SIOPE) Radiation Oncology Working Group presents the QUARTET Project: a centralised quality assurance programme designed to standardise care and improve the quality of radiotherapy and imaging for international clinical trials recruiting children and adolescents with cancer throughout Europe. QUARTET combines the paediatric radiation oncology expertise of SIOPE with the infrastructure and experience of the European Organisation for Research and Treatment of Cancer to deliver radiotherapy quality assurance programmes for large, prospective, international clinical trials. QUARTET-affiliated trials include children and adolescents with brain tumours, neuroblastoma, sarcomas including rhabdomyosarcoma, and renal tumours including Wilms' tumour. With nine prospective clinical trials and two retrospective studies within the active portfolio in March 2022, QUARTET will collect one of the largest repositories of paediatric radiotherapy and imaging data, support the clinical assessment of radiotherapy, and evaluate the role and benefit of radiotherapy quality assurance for this cohort of patients within the context of clinical trials. • High-quality, protocol compliant radiotherapy is essential in clinical trials. • QUARTET is a platform for centralised prospective radiotherapy quality assurance. • QUARTET facilitates a strong collaborative network for paediatric radiation oncology. • QUARTET improves equity in access to paediatric radiotherapy expertise across Europe. • QUARTET supports central review of diagnostic imaging for treatment failure analysis. [ABSTRACT FROM AUTHOR]

Purpose: Expansion of magnetic resonance imaging T2- or T1-tumor lesion volume after radiation therapy (RT) may indicate pseudoprogression (PsPD). The differentiation between true progression and PsPD is a clinical challenge and underinvestigated in pediatric low-grade glioma (LGG). We evaluated radiologic criteria for PsPD after front-line RT and investigated the frequency and duration of PsPD after 3 RT-modalities within the framework of the German pediatric multicenter LGG-studies.Methods and Materials: Baseline and follow-up magnetic resonance imaging scans of 136 patients (72 male [52.9%], median age at start of RT of 11.3 years [range, 0.8-25.9]) of the Society for Pediatric Oncology-LGG 2004 study and LGG-registry cohorts (125iodine-interstitial [IS] RT [n = 51], photon-beam [XRT; n = 60], or proton-beam RT [PBT; n = 25]) were centrally evaluated for increasing: (1) total tumor-associated T2 lesion, (2) focal tumor-associated T2 lesion, and (3) contrast-enhancing tumor during a period of 24 months after RT. The pattern of these criteria initiated "suspicion" of PsPD; their evolution determined "definite" PsPD.Results: Definite PsPD was radiologically determined in 54 of 136 (39.7%) without differences in frequency between RT-modalities: IS 22 of 48 versus XRT 24 of 54 versus PBT 11 of 20; P = .780. Definite PsPD occurred at median 6.3 months (IS 7.2 months; XRT 4.4 months; PBT 6.5 months) after RT-initiation and persisted for median 7.2 months (IS 8.5 months; XRT 7 months; PBT 7.4 months). Appearance of necrosis within the focal tumor-associated T2 lesion proved to be a relevant associated predictor of definite PsPD (P < .001).Conclusions: PsPD is frequent after irradiation of pediatric LGG and independent of the RT modality (IS vs XRT vs PBT). Adequate identification of PsPD versus true progression is imperative to prevent unneeded salvage treatment. [ABSTRACT FROM AUTHOR]

• Neuro contouring atlas to decrease inter- and intra-observer OAR delineation. • The updated atlas was reviewed and approved by 28 experts in the field. • Cognitive functioning and radiological changes related OARs were added. • The atlas (25 OARs) is freely available online on www.cancerdata.org. • Three- dimensional (3D) rendered films are included. To update the digital online atlas for organs at risk (OARs) delineation in neuro-oncology based on high-quality computed tomography (CT) and magnetic resonance (MR) imaging with new OARs. In this planned update of the neurological contouring atlas published in 2018, ten new clinically relevant OARs were included, after thorough discussion between experienced neuro-radiation oncologists (RTOs) representing 30 European radiotherapy-oncology institutes. Inclusion was based on daily practice and research requirements. Consensus was reached for the delineation after critical review. Contouring was performed on registered CT with intravenous (IV) contrast (soft tissue & bone window setting) and 3 Tesla (T) MRI (T1 with gadolinium & T2 FLAIR) images of one patient (1 mm slices). For illustration purposes, delineation on a 7 T MRI without IV contrast from a healthy volunteer was added. OARs were delineated by three experienced RTOs and a neuroradiologist based on the relevant literature. The presented update of the neurological contouring atlas was reviewed and approved by 28 experts in the field. The atlas is available online and includes in total 25 OARs relevant to neuro-oncology, contoured on CT and MRI T1 and FLAIR (3 T & 7 T). Three-dimensional (3D) rendered films are also available online. In order to further decrease inter- and intra-observer OAR delineation variability in the field of neuro-oncology, we propose the use of this contouring atlas in photon and particle therapy, in clinical practice and in the research setting. The updated atlas is freely available on www.cancerdata.org. [ABSTRACT FROM AUTHOR]

About 20% of children with solid tumours (ST) present with distant metastases (DM). Evidence regarding the use of radical radiotherapy of these DM is sparse and open for personal interpretation. The aim of this survey was to review European protocols and to map current practice regarding the irradiation of DM across SIOPE-affiliated countries. Radiotherapy guidelines for metastatic sites (bone, brain, distant lymph nodes, lung and liver) in eight European protocols for rhabdomyosarcoma, non-rhabdomyosarcoma soft-tissue sarcoma, Ewing sarcoma, neuroblastoma and renal tumours were reviewed. SIOPE centres irradiating ≥50 children annually were invited to participate in an online survey. Radiotherapy to at least one metastatic site was recommended in all protocols, except for high-risk neuroblastoma. Per protocol, dose prescription varied per site, and information on delineation and treatment planning/delivery was generally missing. Between July and September 2019, 20/27 centres completed the survey. Around 14% of patients were deemed to have DM from ST at diagnosis, of which half were treated with curative intent. A clear cut-off for a maximum number of DM was not used in half of the centres. Regardless of the tumour type and site, conventional radiotherapy regimens were most commonly used to treat DM. When stereotactic radiotherapy was used, a wide range of fractionation regimens were applied. Current radiotherapy guidelines for DM do not allow a consistent approach in a multicentre setting. Prospective (randomised) trials are needed to define the role of radical irradiation of DM from paediatric ST. • Radical radiotherapy to paediatric solid tumour metastases is mostly unexplored. • In current European protocols, radiotherapy guidelines are inconsistent. • Across 20 major SIOPE centres, a range of radiotherapy approaches were applied. • Trials are needed to define the role of radiotherapy to metastatic sites. [ABSTRACT FROM AUTHOR]

Purpose: The standard of care of childhood parameningeal rhabdomyosarcoma (pRMS) is chemotherapy and local radiation therapy. Protons are increasingly being used to decrease late effects. The aim of the present study is to analyze the pattern of relapse and the correlation with dosimetric factors in pRMS treated with proton therapy.Methods and Materials: This retrospective evaluation includes children treated in our institution for pRMS. Information on demographics, treatment, tumor characteristics, and toxicities and outcome was prospectively collected within the in-house registry. For patients presenting with local relapse, a fusion of the dosimetry with magnetic resonance imaging displaying site and geometry of recurrence was performed.Results: Median follow-up time was 2.9 years (0.5-4.7). Forty-six patients were identified in our institution between July 2013 and November 2017. Main characteristics of patients were as follows: 56.5% male, median age 5.1 years (1.3-17.5), 39.1% alveolar histology, 26.1%, 52.2%, 8.7%, and 13% patients with subgroup risk classification D, E/F/G, H, or metastatic, respectively, median total prescribed dose 55.8 Gy (50.4-56.4). Estimated 2-year local control, metastasis-free survival, event-free survival, and overall survival were 83.8%, 87.8%, 76.9%, and 88.9%, respectively. No acute or late local toxicity exceeding grade 3 was observed. Risk-group was identified as prognostic factor for metastasis-free survival in univariate analysis but not in multivariate analysis (trend: P = .09). In this cohort, dosimetric factors did not correlate with outcome. Isolated local failure happened in 5 of the 11 relapses. Local relapses were matched with dosimetry for 6 patients: 4 of them occurred in the high dose volume and 2 in the intermediate or low dose volume.Conclusions: Proton therapy was effective and well feasible even in a critical cohort. Still, local relapse within the target volume of the radiation therapy remains an important issue in pRMS and new treatment strategies are needed. [ABSTRACT FROM AUTHOR]

• Significant high variability is observed in vertebral delineation, despite consensus guidelines. • Variations in vertebral delineation impact dosimetry. • Sparing of non-adjacent vertebrae is more challenging with protons. • Trial radiotherapy guideline compliance is increasing over time. Irradiation of the vertebrae in prepubertal patients, if non-homogenous, can result in future growth deformities including kyphoscoliosis. Vertebral delineation and dosimetry were assessed for 101 paediatric cases reviewed within QUARTET-affiliated trials. Despite the availability of published consensus guidelines, a high variability in vertebral delineation was observed, with impact on dosimetry. [ABSTRACT FROM AUTHOR]

Objective To develop a consensus guideline for craniospinal target volume (TV) delineation in children and young adults participating in SIOPE studies in the era of high-precision radiotherapy. Methods and materials During four consensus meetings (Cambridge, Essen, Liverpool, and Marseille), conventional field-based TV has been translated into image-guided high-precision craniospinal TV by a group of expert paediatric radiation oncologists and enhanced by MRI images of liquor distribution. Results The CTV cranial should include the whole brain, cribriform plate, most inferior part of the temporal lobes, and the pituitary fossa. If the full length of both optic nerves is not included, the dose received by different volumes of optic nerve should be recorded to correlate with future patterns of relapse (no consensus). The CTV cranial should be modified to include the dural cuffs of cranial nerves as they pass through the skull base foramina. Attempts to spare the cochlea by excluding CSF within the internal auditory canal should be avoided. The CTV spinal should include the entire subarachnoid space, including nerve roots laterally. The lower limit of the spinal CTV is at the lower limit of the thecal sac, best visible on MRI scan. There is no need to include sacral root canals in the spinal CTV. Conclusion This consensus guideline has the potential to improve consistency of craniospinal TV delineation in an era of high-precision radiotherapy. This proposal will be incorporated in the RTQA guidelines of future SIOPE-BTG trials using CSI. [ABSTRACT FROM AUTHOR]

To establish an international quality standard for contouring and planning for high-risk neuroblastoma within the prospective High-Risk Neuroblastoma Study 2 of SIOP-Europe-Neuroblastoma (SIOPEN HR-NBL2), which includes a randomized question on dose escalation for residual disease. Data on four patients with high-risk neuroblastoma were selected and distributed to the radiotherapy committee of the HR-NBL2 study for independent contouring and planning. Differences in contouring were analyzed using apparent and kappa-corrected agreement. Plans were analyzed regarding the dose-volume histogram metrics. Results were discussed among experts and agreement was obtained. Substantial agreement was found for contouring of the heart (0.64), liver (0.70), left lung (0.74), and right lung (0.74). For contouring of the gastrointestinal tract (0.54), left kidney (0.60), and right kidney (0.59) moderate agreement was obtained. For target volume delineation, agreement for preoperative tumour extent was moderate (0.42), for CTV fair (0.35) and only low (0.06) for residual tumour, respectively. The dose planning strategies appeared to be relatively homogeneous among all experts. Considerable variability was found for the delineation of target volumes, particularly the boost volume, whereas the contouring of the organs at risk and the planning strategy were reasonably consistent. In order to obtain reliable results from the randomized HR-NBL2 trial, standardization of target volume delineation based on adequate imaging is crucial. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate postoperative spot-scanning proton radiation therapy (PT) and intensity-modulated PT (IMPT) for chordoma and chondrosarcoma in pediatric patients. Methods and Materials: Between 2000 and 2005, 10 patients (six male patients, four female patients; six chordomas, four chondrosarcomas), aged 10–20 years (median, 16 years), were treated at our institute. Tumor sites were in the brain (one case), skull base (five cases), cervical (three cases), and lumbar spine (one case). Three children had complete resections. In seven children, resection was incomplete, leaving residual tumor behind (range, 2.3–46.3 mL). PT was delivered using spot scanning, with (three patients) or without (seven patients) IMPT. Total dose was 74.0 cobalt Gray equivalents (CGE) for chordoma, and 63.2–68.0 CGE for chondrosarcoma (median, 66.0), depending on histopathological grading and whether the patient had concurrent chemotherapy. Results: Median follow-up time was 36 months (range, 8−77 months). Radiation treatment was well tolerated. All patients remained failure-free at their last follow-up. Late adverse events were reported in three patients and were mild (neurosensory in one patient; alopecia and hypoaccusis in one patient) to moderate (one patient, Grade 2 pituitary insufficiency). Conclusions: Postoperative spot-scanning PT, delivered in combination with and without IMPT, for chordoma and chondrosarcoma in children and adolescents was tolerated without unacceptable adverse event and initial outcome is perfectly satisfactory in this small cohort. Longer follow-up time and larger cohort are needed to more fully assess tumor control, adverse events, as well as functional and cosmetic outcome. [Copyright &y& Elsevier]

Background and purpose: To assess the safety and efficacy of spot scanning proton beam radiation therapy (PRT) in the treatment of intracranial meningiomas.Patients and methods: Sixteen patients with intracranial meningioma (histopathologically proven in 13/16 cases) were treated with PRT between July 1997 and July 2002. Eight patients had skull base lesions. Thirteen patients received PRT after surgery either as adjuvant therapy for incomplete resection (eight patients) or for recurrence (five patients). Three patients received radical PRT after presumptive diagnosis based on imaging. The median prescribed dose was 56 CGE (range, 52.2–64, CGE=proton Gy X 1.1) at 1.8–2.0 CGE (median, 2.0) per fraction. Gross tumor volume and planning target volume ranged from 0.8 to 87.6 cc (median, 17.5) and 4.6–208.1 cc (median 107.7), respectively. Late ophthalmologic and non-ophthalmologic toxicity was assessed using the Subjective, Objective, Management and Analytic scale (SOMA) of the Late Effects of Normal Tissue scoring system and National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE, v3.0) grading system, respectively. The median follow-up time was 34.1 months (range, 6.5–67.8).Results: Cumulative 3-year local control, progression-free survival and overall survival were 91.7, 91.7 and 92.7%, respectively. No patient died from recurrent meningioma. One patient progressed locally after PRT. Radiographic follow-up (median, 34 months) revealed an objective response in three patients and stable disease in 12 patients. Cumulative 3-year toxicity free survival was 76.2%. One patient presented with radiation induced optic neuropathy (SOMA Grade 3) and retinopathy (SOMA Grade 2) 8.8 and 30.4 months after treatment, respectively. These patients with ophthalmologic toxicity received doses higher than those allowed for the optic/ocular structures. Another patient developed a symptomatic brain necrosis (CTCAE Grade 4) 7.2 months after treatment. No radiation-induced hypothalamic/pituitary dysfunction was observed.Conclusions: Spot-scanning PRT is an effective treatment for patient with untreated, recurrent or incompletely resected intracranial meningiomas. It offers highly conformal irradiation for complex-shaped intracranial meningiomas, while delivering minimal non-target dose. Observed ophthalmologic toxicity is dose-related. [Copyright &y& Elsevier]

Purpose: To evaluate effectiveness and safety of spot-scanning-based proton-radiotherapy (PT) for extracranial chordomas (ECC). Methods and Material: Between 1999–2006, 40 patients with chordoma of C-, T-, and L-spine and sacrum were treated at Paul Scherrer Institute (PSI) with PT using spot-scanning. Median patient age was 58 years (range, 10–81 years); 63% were male, and 36% were female. Nineteen patients (47%) had gross residual disease (mean 69 cc; range, 13–495 cc) before PT, and 21 patients (53%) had undergone prior titanium-based surgical stabilization (SS) and reconstruction of the axial skeleton. Proton doses were expressed as Gy(RBE). A conversion factor of 1.1 was used to account for higher relative biological effectiveness (RBE) of protons compared with photons. Mean total dose was 72.5 Gy(RBE) [range, 59.4–75.2 Gy(RBE)] delivered at 1.8–2.0 Gy(RBE) dose per fraction. Median follow-up time was 43 months. Results: In 19 patients without surgical stabilization, actuarial local control (LC) rate at 5 years was 100%. LC for patients with gross residual disease but without surgical stabilization was also 100% at 5 years. In contrast, 12 failures occurred in 21 patients with SS, yielding a significantly decreased 5-year LC rate of 30% (p = 0.0003). For the entire cohort, 5-year LC rates were 62%, disease-free survival rates were 57%, and overall survival rates were 80%. Rates were 100% for patients without SS. No other factor, including dosimetric parameters (V95, V80) were predictive for tumor control on univariate analysis. Conclusion: Spot-scanning-based PT at PSI delivered subsequently to function-preserving surgery for tumor debulking, decompression of spinal cord, or biopsy only is safe and highly effective in patients with ECC without major surgical instrumentation even in view of large, unresectable disease. [ABSTRACT FROM AUTHOR]