Late toxicity in the brain after radiotherapy for sinonasal cancer: Neurocognitive functioning, MRI of the brain and quality of life

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Compared with matched normative data, impaired cognitive function was substantial.

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Several correlations between radiation dose and cognitive impairment were present.

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Radiation-induced white matter hyperintensities were present in 2/27 participants.

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One participant displayed radiation-induced necrosis in the temporal lobe.

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The domains affecting quality of life the most were fatigue and quality of sleep.

Purpose

The aim of the study was to evaluate neurocognitive late effects, structural alterations and associations between cognitive impairment and radiation doses as well as cerebral tissue damage after radiotherapy for sinonasal cancer. Furthermore, the aim was to report quality of life (QoL) and self-reported cognitive capacity.

Materials and methods

Recurrence-free patients previously treated with intensity-modulated radiotherapy with a curative intent were eligible for the study. Study examinations comprised comprehensive neurocognitive testing, MRI of the brain, and self-reported outcomes.

Results

A total of 27 patients were included. Median age was 67 years (range 47–83). The majority of test outcomes were below normative values in any degree, and 37% of the participants had clinically significant neurocognitive impairment when compared with normative data. Correlations between absorbed doses to specific substructures of the brain and neurocognitive outcomes were present for Wechsler’s Adult Intelligence Scale-digit span and Controlled Oral Word Association Test-S. Structural MRI revealed macroscopic abnormalities in three patients; infarction (n = 1), diffuse white matter intensities (n = 2) and necrosis (n = 1). In the analysis of atrophy of cerebral tissue, no correlations were present with neither radiation dose to cerebral substructures nor neurocognitive impairment. The global QoL of the cohort was 75. The most affected outcomes were ‘fatigue’, ‘insomnia’, and ‘drowsiness’. A total of 59% of participants reported significantly impaired quality of sleep. Self-reported cognitive function revealed that ‘memory’ was the most affected cognitive domain. For the domains of ‘memory’ and ‘language’, self-reported functioning was associated with objectively measured neurocognitive outcomes.

Conclusion

Cerebral toxicity after radiotherapy for sinonasal cancer was substantial. Clinically significant cognitive impairment was present in more than one third of the participants, and several dose–response associations were present. Furthermore, the presence of macroscopic radiation sequelae indicated considerable impact of radiotherapy on brain tissue.

Proton therapy and the European Particle Therapy Network: The past, present and future

Proton therapy is delivered to selected cancer patients presenting with rare tumours, for which a dose escalation paradigm and/or a reduced dose-bath to the organs at risk is pursued. It is a costly treatment with an additional cost factor of 2–3 when compared to photon radiotherapy. Notwithstanding the 180′000 patients treated with protons, scars robust clinical evidence is available to justify the administration of this treatment modality. The European Particle Therapy Network (EPTN) was created in 2015 to answer the critical European needs for cooperation among protons and carbon ions centres in the framework of clinical research networks. EPTN with other European groups will launch a number of prospective clinical trials that could be practice changing if positive. Alternative way to generate clinical data could be provided by alternative methodologies, such as the Dutch model-based approach, or could be provided by European infrastructure projects.

NTCP model validation method for DAHANCA patient selection of protons versus photons in head and neck cancer radiotherapy

Introduction: Prediction models using logistic regression may perform poorly in external patient cohorts. However, there is a need to standardize and validate models for clinical use. The purpose of this project was to describe a method for validation of external NTCP models used for patient selection in the randomized trial of protons versus photons in head and neck cancer radiotherapy, DAHANCA 35. Material and methods: Organs at risk of 588 patients treated primarily with IMRT in the randomized controlled DAHANCA19 trial were retrospectively contoured according to recent international recommendations. Dose metrics were extracted using MatLab and all clinical parameters were retrieved from the DAHANCA database. The model proposed by Christianen et al. to predict physician-rated dysphagia was validated through the closed testing, where change of the model intercept, slope and individual beta's were tested for significant prediction improvements. Results: Six months prevalence of dysphagia in the validation cohort was 33%. The closed testing procedure for physician-rated dysphagia showed that the Christianen et al. model needed an intercept refitting for the best match for the Danish patients. The intercept update increased the risk of dysphagia for the validation cohort by 7.9 ± 2.5% point. For the raw model performance, the Brier score (mean squared residual) was 0.467, which improved significantly with a new intercept to 0.415. Conclusions: The previously published Dutch dysphagia model needed an intercept update to match the Danish patient cohort. The implementation of a closed testing procedure on the current validation cohort allows quick and efficient validation of external NTCP models for patient selection in the future.

The HERO Project: Inspire Awareness, Strengthen Radiotherapy, Deliver Equitable Access

Half of all cancer patients in Europe should receive radiotherapy (RT) during the treatment of their disease. But there is a remaining gap in RT provision, leading to suboptimal access. Additionally, healthcare budgets are tight, and economic evaluations are key to support decision making. The HERO project (Health Economics in Radiation Oncology) is developing a knowledge base for health economic evaluation of RT at the European level. It aims to provide solid data to engage with decision makers; it empowers the RT community to advocate for better resource planning and ultimately better care for patients, closing the gap in RT access. The project assessed the availability of RT in Europe, in terms of equipment, staffing and guidelines. Then, it investigated the need for RT in Europe. Applying available EU data to the CCORE group (Collaboration for Cancer Outcomes Research and Evaluation) decision trees of evidence-based indications, the RT optimal utilization proportion, existing gap and growing needs have been calculated. Finally, knowing the cost of treatment is needed for budget planning and reimbursement settings, HERO developed a cost accounting model, applying a time-driven activity-based costing (TD-ABC) methodology. The model gives insight on the national cost of RT: per treatment, on average and for various tumor types and techniques, on the resources required based on national patterns of care. Regarding availability of human and capital resources, there are big discrepancies in Europe, with sixfold variations across European countries for some of the resources. Looking at the need, while on average 51% of all cancer patients should receive RT, we miss out 30% of these. The need is further expected to increase with an average of 16% by 2025. Lastly, the HERO costing model is accessible online. Preliminary results are available for a fictitious country (Europalia), whose RT scenario is based on standard European practices: to serve a hypothetical cancer patient cohort of 100,000, the model computes an annual RT budget of 173,192,960€, an average RT treatment cost of 3518€ and, for common cancer types, an average breast and prostate treatment cost of respectively 3785 and 6092€. Currently, the model is used in Belgium, to help defining resource recommendations, and other countries are setting up task forces for the implementation of the tool nationally. HERO allows to advocate for RT and negotiate with decision makers, who need data on availability, needs and costs, when planning RT resources within their country. In addition, knowledge of the RT cost will promote and further ease cost-effectiveness analyses as well as the development of value-based health care oncology programs. Overall, the HERO project creates a movement of awareness within the cancer community, encourages national RT data collection and supports the promotion of optimal access to care with the ultimate aim of better outcome for the cancer patient.