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- Bentzen, Søren M., et al.
(författare)
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Towards evidence-based guidelines for radiotherapy infrastructure and staffing needs in Europe : the ESTRO QUARTS project
- 2005
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 75:3, s. 355-65
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Adequate and equitable access to radiotherapy (RT) must be a reasonable health care goal for the EU. However, there are large variations among the EU countries and even regional variations within countries in the provision of RT. In this report, we combine the best available evidence on the indications for RT with national epidemiological data to arrive at estimates for the appropriate level of RT infrastructure in the 25 EU countries. PATIENTS AND METHODS: Data from three systematic overviews of the best available evidence for the indication for RT in 23 main cancer types are combined with epidemiological data from the EUCAN and GLOBOCAN databases on the crude incidence of each of these cancers in the 25 EU countries. Together with published benchmarks for accelerator throughput this allows estimation of the number of linear accelerators per million people required to facilitate appropriate RT utilization rates in each country. Where possible, the estimates are compared with the detailed data available from Sweden. RESULTS: The crude incidence of the main cancer types shows large variation among the 25 EU countries. This reflects in part differences in exposure to aetiological risk factors and partly differences among the countries in population age structure. Correspondingly, the estimate of the required number of linear accelerators per million people showed considerable variation: ranging from 4.0 in Cyprus to 8.1 in Hungary. The average for the 25 countries was 5.9 per million people. These estimates were compared with available national guidelines and actual data on RT infrastructure and large shortfalls were found in many countries. Implications for health economics and capacity planning are briefly discussed. CONCLUSIONS: The QUARTS project has developed a model that establishes a direct and transparent link between epidemiological data and indications for RT based on the best available evidence. Comparison of the model estimates with current levels of RT infrastructure has revealed major inequalities in provision of RT in the 25 EU countries. Continuation of this study is recommended as a way of improving RT provision on rational grounds throughout the European community and as a model for health care planning in the EU.
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| 2. |
- Blomstrand, Malin, et al.
(författare)
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Estimated clinical benefit of protecting neurogenesis in the developing brain during radiation therapy for pediatric medulloblastoma.
- 2012
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Ingår i: Neuro-Oncology. - : Oxford University Press (OUP). - 1523-5866 .- 1522-8517. ; 14:7, s. 882-889
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Tidskriftsartikel (refereegranskat)abstract
- We sought to assess the feasibility and estimate the benefit of sparing the neurogenic niches when irradiating the brain of pediatric patients with medulloblastoma (MB) based on clinical outcome data. Pediatric MB survivors experience a high risk of neurocognitive adverse effects, often attributed to the whole-brain irradiation that is part of standard management. Neurogenesis is very sensitive to radiation, and limiting the radiation dose to the hippocampus and the subventricular zone (SVZ) may preserve neurocognitive function. Radiotherapy plans were created using 4 techniques: standard opposing fields, intensity-modulated radiotherapy (IMRT), intensity-modulated arc therapy (IMAT), and intensity-modulated proton therapy (IMPT). Mean dose to the hippocampus and SVZ (mean for both sites) could be limited to 88.3% (range, 83.6%-91.0%), 77.1% (range, 71.5%-81.3%), and 42.3% (range, 26.6%-51.2%) with IMAT, IMRT, and IMPT, respectively, while maintaining at least 95% of the prescribed dose in 95% of the whole-brain target volume. Estimated risks for developing memory impairment after a prescribed dose of 23.4 Gy were 47% (95% confidence interval [CI], 21%-69%), 44% (95% CI, 21%-65%), 41% (95% CI, 22%-60%), and 33% (95% CI, 23%-44%) with opposing fields, IMAT, IMRT, and IMPT, respectively. Neurogenic niche sparing during cranial irradiation of pediatric patients with MB is feasible and is estimated to lower the risks of long-term neurocognitive sequelae. Greatest sparing is achieved with intensity-modulated proton therapy, thus making this an attractive option to be tested in a prospective clinical trial.
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| 3. |
- Brodin, N Patrik, et al.
(författare)
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Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique.
- 2014
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Ingår i: Neuro-oncology. - : Oxford University Press (OUP). - 1523-5866 .- 1522-8517. ; 16:4, s. 594-602
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundWe investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy.MethodsWe included 17 pediatric medulloblastoma patients to represent the variability in tumor location relative to the hippocampal region. Treatment plans were generated using 3D conformal radiotherapy, hippocampal sparing intensity-modulated radiotherapy, and spot-scanned proton therapy, using 3 different treatment margins for the conformal tumor boost. Neurocognitive impairment risk was estimated based on dose-response models from pediatric CNS malignancy survivors and compared among different margins and treatment techniques.ResultsMean hippocampal dose and corresponding risk of cognitive impairment were decreased with decreasing treatment margins (P < .05). The largest risk reduction, however, was seen when applying hippocampal sparing proton therapy-the estimated risk of impaired task efficiency (95% confidence interval) was 92% (66%-98%), 81% (51%-95%), and 50% (30%-70%) for 3D conformal radiotherapy, intensity-modulated radiotherapy, and proton therapy, respectively, for the smallest boost margin and 98% (78%-100%), 90% (60%-98%), and 70% (39%-90%) if boosting the whole posterior fossa. Also, the distance between the closest point of the planning target volume and the center of the hippocampus can be used to predict mean hippocampal dose for a given treatment technique.ConclusionsWe estimate a considerable clinical benefit of hippocampal sparing radiotherapy. In choosing treatment margins, the tradeoff between margin size and risk of neurocognitive impairment quantified here should be considered.
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| 4. |
- Brodin, N. Patrik, et al.
(författare)
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Modeling freedom from progression for standard-risk medulloblastoma : A mathematical tumor control model with multiple modes of failure
- 2013
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 0360-3016. ; 87:2, s. 422-429
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Tidskriftsartikel (refereegranskat)abstract
- Purpose As pediatric medulloblastoma (MB) is a relatively rare disease, it is important to extract the maximum information from trials and cohort studies. Here, a framework was developed for modeling tumor control with multiple modes of failure and time-to-progression for standard-risk MB, using published pattern of failure data. Methods and Materials Outcome data for standard-risk MB published after 1990 with pattern of relapse information were used to fit a tumor control dose-response model addressing failures in both the high-dose boost volume and the elective craniospinal volume. Estimates of 5-year event-free survival from 2 large randomized MB trials were used to model the time-to-progression distribution. Uncertainty in freedom from progression (FFP) was estimated by Monte Carlo sampling over the statistical uncertainty in input data. Results The estimated 5-year FFP (95% confidence intervals [CI]) for craniospinal doses of 15, 18, 24, and 36 Gy while maintaining 54 Gy to the posterior fossa was 77% (95% CI, 70%-81%), 78% (95% CI, 73%-81%), 79% (95% CI, 76%-82%), and 80% (95% CI, 77%-84%) respectively. The uncertainty in FFP was considerably larger for craniospinal doses below 18 Gy, reflecting the lack of data in the lower dose range. Conclusions Estimates of tumor control and time-to-progression for standard-risk MB provides a data-driven setting for hypothesis generation or power calculations for prospective trials, taking the uncertainties into account. The presented methods can also be applied to incorporate further risk-stratification for example based on molecular biomarkers, when the necessary data become available.
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