ESTRO ACROP and SIOPE recommendations for myeloablative total body irradiation in children

Background and purpose: Myeloablative Total Body Irradiation (TBI) is an important modality in conditioning for allogeneic hematopoietic stem cell transplantation (HSCT), especially in children with high-risk acute lymphoblastic leukemia (ALL). TBI practices are heterogeneous and institution-specific. Since TBI is associated with multiple late adverse effects, recommendations may help to standardize practices and improve the outcome versus toxicity ratio for children. Material and methods: The European Society for Paediatric Oncology (SIOPE) Radiotherapy TBI Working Group together with ESTRO experts conducted a literature search and evaluation regarding myeloablative TBI techniques and toxicities in children. Findings were discussed in bimonthly virtual meetings and consensus recommendations were established. Results: Myeloablative TBI in HSCT conditioning is mostly performed for high-risk ALL patients or patients with recurring hematologic malignancies. TBI is discouraged in children <3–4 years old because of increased toxicity risk. Publications regarding TBI are mostly retrospective studies with level III–IV evidence. Preferential TBI dose in children is 12–14.4 Gy in 1.6–2 Gy fractions b.i.d. Dose reduction should be considered for the lungs to <8 Gy, for the kidneys to ≤10 Gy, and for the lenses to <12 Gy, for dose rates ≥6 cGy/min. Highly conformal techniques i.e. TomoTherapy and VMAT TBI or Total Marrow (and/or Lymphoid) Irradiation as implemented in several centers, improve dose homogeneity and organ sparing, and should be evaluated in studies. Conclusions: These ESTRO ACROP SIOPE recommendations provide expert consensus for conventional and highly conformal myeloablative TBI in children, as well as a supporting literature overview of TBI techniques and toxicities

Advances in radiotherapy technology for pediatric cancer patients and roles of medical physicists: COG and SIOP Europe perspectives

Over the last two decades, rapid technological advances have dramatically changed radiation delivery to children with cancer, enabling improved normal-tissue sparing. This article describes recent advances in photon and proton therapy technologies, image-guided patient positioning, motion management, and adaptive therapy that are relevant to pediatric cancer patients. For medical physicists who are at the forefront of realizing the promise of technology, challenges remain with respect to ensuring patient safety as new technologies are implemented with increasing treatment complexity. The contributions of medical physicists to meeting these challenges in daily practice, in the conduct of clinical trials, and in pediatric oncology cooperative groups are highlighted. Representing the perspective of the physics committees of the Children\u27s Oncology Group (COG) and the European Society for Paediatric Oncology (SIOP Europe), this paper provides recommendations regarding the safe delivery of pediatric radiotherapy. Emerging innovations are highlighted to encourage pediatric applications with a view to maximizing the therapeutic ratio

Training and Education of Pediatric Radiation Oncologists: A Survey from the 2019 Pediatric Radiation Oncology Society Meeting

To examine the educational background, clinical practice, and preferences regarding continuing medical education (CME) among radiation oncologists who attended the 2019 meeting of the Pediatric Radiation Oncology Society (PROS), a survey consisting of 20 questions was distributed asking for demographic and educational background, clinical practice, and preferences regarding pediatric radiation oncology CME. Of 188 participants, 130 (69.2%) returned the questionnaire. More than 80% reported access to CT simulation, three-dimensional radiotherapy, and general anesthesia while \u3c30% had access to intraoperative radiotherapy, proton, and heavy particle therapy. After residency, 12.1% did further training in pediatric radiation oncology. When asked about further training in pediatrics after residency, 88.8% answered that there should be a formal training program beyond residency in order to treat children. More than 75% acquired knowledge in pediatric radiation oncology through journals, books, live meetings, and tumor boards. The results of this survey may help Pediatric Radiation Oncology Society (PROS) in creating guidelines and recommendations for improvement in pediatric radiation oncology training and practice support as well as the development of CME activities most likely to benefit practitioners

Inter-observer variation in target delineation and dose trade-off for radiotherapy of paediatric ependymoma

Postoperative radiotherapy for intracranial paediatric ependymoma is challenging both for target definition and treatment planning [1]. Delineation of the tumour bed is difficult, as structures in prior contact with the tumour will shift back into their original positions after surgery. In infratentorial cases, the target is adjacent to the brainstem and upper spinal cord, therefore the relatively high prescription dose and sparing of surrounding organs at risk (OARs) need to be balanced. Through the radiotherapy working-group of the Nordic Organization of Pediatric Hematology and Oncology (NOPHO) and in collaboration with the Westdeutsches Protonentherapizentrum Essen (WPE), a study was performed to quantify inter-centre variations in target delineation and treatment plans for these tumours

Management of vertebral radiotherapy dose in paediatric patients with cancer : consensus recommendations from the SIOPE radiotherapy working group

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