| 1. |
- Martinsson, Ulla, et al.
(författare)
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Complications after proton radiotherapy in children, focusing on severe late complications. A complete Swedish cohort 2008-2019
- 2023
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Ingår i: ACTA ONCOLOGICA. - : Taylor & Francis. - 0284-186X .- 1651-226X. ; 62:10, s. 1348-1356
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Tidskriftsartikel (refereegranskat)abstract
- Background: Proton radiotherapy (RT) is an attractive tool to deliver local therapy with minimal dose to uninvolved tissue, however, not suitable for all patients. The aim was to explore complications, especially severe late complications (grades 3-4), following proton RT delivered to a complete Swedish cohort of paediatric patients aged <18 years treated 2008-2019.Material and Methods: Data was downloaded from a national registry. Complications with a possible causation with RT are reported. Proton treatments until July 2015 was performed with a fixed horizontal 172 MeV beam (The Svedberg Laboratory (TSL), Uppsala) in a sitting position and thereafter with gantry-based pencil-beam scanning technique (Skandion Clinic, Uppsala) in a supine position.Results: 219 courses of proton RT (77 at TSL and 142 at Skandion) were delivered to 212 patients (mean age 9.2 years) with various tumour types (CNS tumours 58%, sarcomas 26%, germ cell tumours 7%). Twenty-five patients had severe acute complications (skin, mucous membrane, pharynx/oesophagus, larynx, upper gastrointestinal canal, lower gastrointestinal canal, eyes, ears). Fifteen patients had severe late complications; with increased proportion over time: 4% at 1-year follow-up (FU), 5% at 3-year, 11% at 5-year. Organs affected were skin (1 patient), subcutaneous tissue (4), salivary glands (1), upper GI (1), bone (7), joints (2), CNS (2), PNS (1), eyes (1) and ears (5). Twenty-one of the 28 patients with 10-year FU had at least one late complication grades 1-4 and fourteen of them had more than one (2-5 each).Conclusion: The most important result of our study is the relatively low proportion of severe late complications, comparable with other proton studies on various tumours. Furthermore, the numbers of late complications are lower than our own data set on a mixed population of photon and proton treated paediatric patients, assuring the safety of using proton therapy also in the clinical practice.
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| 2. |
- Kristensen, Ingrid, et al.
(författare)
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A dose based approach for evaluation of inter-observer variations in target delineation
- 2017
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Ingår i: Technical Innovations and Patient Support in Radiation Oncology. - : Elsevier. - 2405-6324. ; 3-4, s. 41-47
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Substantial inter-observer variations in target delineation have been presented previously. Target delineation for paediatric cases is difficult due to the small number of children, the variation in paediatric targets, the number of study protocols, and the individual patient's specific needs and demands. Uncertainties in target delineation might lead to under-dosage or over-dosage. The aim of this work is to apply the concept of a consensus volume and good quality treatment plans to visualise and quantify inter-observer target delineation variations in dosimetric terms in addition to conventional geometrically based volume concordance indices.Material and methods: Two paediatric cases were used to demonstrate the potential of adding dose metrics when evaluating target delineation diversity; Hodgkin's disease (case 1) and rhabdomyosarcoma of the parotid gland (case 2). The variability in target delineation (PTV delineations) between six centres was quantified using the generalised conformity index, CIgen, generated for volume overlap. The STAPLE algorithm, as implemented in CERR, was used for both cases to derive a consensus volumes. STAPLE is a probabilistic estimate of the true volume generated from all observers. Dose distributions created by each centre for the original target volumes were then applied to this consensus volume.Results: A considerable variation in target segmentation was seen in both cases. For case 1 the variation was 374-960 cm3 (average 669 cm3) and for case 2; 65-126 cm3 (average 109 cm3). CIgen were 0.53 and 0.70, respectively. The DVHs in absolute volume displayed for the delineated target volume as well as for the consensus volume adds information on both ''compliant" target volumes as well as outliers which are hidden with just the use of concordance indices.Conclusions: The DVHs in absolute volume add valuable and easily understood information to various indices for evaluating uniformity in target delineation.
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| 3. |
- Embring, Anna
(författare)
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Radiotherapy in advanced head and neck cancer
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Head and neck cancer (HNC) is a group of malignant tumours located in the mucosa of the upper aero-digestive tract. The location of the tumour, close to several critical organs, can often result in great suffering for the patient both due to the tumour itself but also the treatment can be associated with side effects impairing quality of life. The prognosis in HNC varies greatly by primary tumour site and tumour stage at presentation, but as a group approximately two thirds of patients will still be alive 5 years after diagnosis. The predominant pattern of failure is local recurrence, and this thesis addresses this problem with a focus on 1) how to treat recurrent head and neck cancer with re-irradiation, and 2) achieving improved local control at first diagnosis by dose-escalated radiotherapy. In Paper I we investigated the overlapping volumes in re-irradiation for HNC. We found that that there is a lack of consensus regarding the definition of re-irradiation in HNC and in this study, we used a more strict definition than in previously published material and propose that future studies on re-irradiation should do the same, making it possible to compare results from different studies. We also found that severe acute side effects were more common in patients who received a cumulative dose of ≥100 Gy in the overlapping volume. In Paper II we investigated the association between cumulative doses to organs at risk and serious late side effects in re-irradiation for HNC. We found an association between the dose to the carotid arteries and the risk of developing carotid blowout syndrome, and similarly, between the dose to bone and osteoradionecrosis. Our results support the existing proposed dose constraint for the carotid arteries of a cumulative dose of 120 Gy. In Paper III we investigated two different modalities of achieving radiation dose escalation of the primary tumour in oropharyngeal cancer, simultaneous integrated boost (SIB) and brachytherapy boost. In our analyses we found no differences in survival or serious side effects comparing the two different boost modalities, suggesting that the two treatment options are equal in these respects. In Paper IV we investigated a cohort of 215 patients who had received dose-escalated radiotherapy for oropharyngeal cancer and a matched cohort of 215 patients who had received standard dose radiotherapy to compare survival outcome and serious side effects. We found no predictive factors to guide selection patients for dose-escalated radiotherapy. However, the remarkably good overall survival in the dose-escalated cohort, despite an overrepresentation of advanced T-stage tumours, encourages further attempts to identify such factors. We also found that osteoradionecrosis and dysphagia were more common after treatment with dose-escalated radiotherapy compared to standard dose radiotherapy.
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| 4. |
- Embring, A., et al.
(författare)
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Re-irradiation in Paediatric Tumours of the Central Nervous System: National Guidelines from the Swedish Workgroup of Paediatric Radiotherapy
- 2023
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Ingår i: Clinical Oncology. - : Elsevier. - 0936-6555 .- 1433-2981. ; 35:9, s. 571-575
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Tidskriftsartikel (refereegranskat)abstract
- There is a lack of clinical protocols for re-irradiation in paediatric central nervous system (CNS) tumours. To fill this void, the Swedish Workgroup of Paediatric Radiotherapy (SBRTG) compiled national guidelines on re-irradiation in paediatric CNS tumours (diffuse intrinsic pontine glioma, ependymoma, germinoma and medulloblastoma). These have been in clinical practice since 2019 in all paediatric radiotherapy centres in Sweden. Since the implementation, the guidelines have been complemented with a yearly review on clinical outcome and toxicities in all paediatric patients treated according to the guidelines. This article presents the Swedish national guidelines on re-irradiation in paediatric CNS tumours. & COPY; 2023 Published by Elsevier Ltd on behalf of The Royal College of Radiologists.
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| 5. |
- Toussaint, Laura, et al.
(författare)
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Inter-observer variation in target delineation and dose trade-off for radiotherapy of paediatric ependymoma
- 2022
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 61:2, s. 235-238
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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