T. Mee

Radiotherapy Demand and Activity in England 2006–2020

AIMS This paper compares the predictions of radiotherapy demand for England from the Malthus model with those from the earlier National Radiotherapy Advisory Group (NRAG) model, from the international literature and also with observed radiotherapy usage in England as a whole as recorded in the English radiotherapy dataset (RTDS). MATERIALS AND METHODS We reviewed the evidence base for radiotherapy for each type and stage of cancer using national and international guidelines, meta-analyses, systematic reviews and key clinical trials. Twenty-two decision trees were constructed and radiotherapy demand was calculated using English cancer incidence data for 2007, 2008 and 2009, accurate to the Primary Care Trust (PCT) level (population 91,500-1,282,384). The stage at presentation was obtained from English cancer registry data. In predictive mode, the model can take account of changes in cancer incidence as the population grows and ages. RESULTS The Malthus model indicates reduced indications for radiotherapy, principally for lung cancer and rarer tumours. Our estimate of the proportion of patients who should receive radiotherapy at some stage of their illness is 40.6%. This is lower than previous estimates of about 50%. Nevertheless, the overall estimate of demand in terms of attendances is similar for the NRAG and Malthus models. The latter models that 48,827 attendances should have been delivered per million population in 2011. National data from RTDS show 32,071 attendances per million in 2011. A 50% increase in activity would be required to match estimated demand. This underprovision extends across all cancers and represents reduced access and the use of dose fractionation at odds with international norms of evidence-based practice. By 2016, demand is predicted to grow to about 55,206 attendances per million and by 2020 to 60,057. DISCUSSION Services have increased their activity by 14% between 2006 and 2011, but estimated demand has increased by 11%. Access remains low and English radiotherapy dose fractionation still does not comply with international evidence-based practice.

The Malthus Programme — A New Tool for Estimating Radiotherapy Demand at a Local Level

The radiotherapy delivery service in England is emerging from a 25 year blight on strategic planning and forecasting of radiotherapy demand. Two of the most influential documents used as evidence for renovation and expansion in radiotherapy services are the Royal College of Radiologists (RCR) equipment, workload and staffing survey [1] and the National Radiotherapy Advisory Group (NRAG) report [2]. Where the RCR survey quantified significant variation in allocation and consumption of radiotherapy resources across England and Wales, the NRAG 2007 report generated national targets for radiotherapy service provision in terms of fraction burden (40,000 fractions per million of population by 2010 and up to 54,000 fractions per million by 2016) and the proportion of cancer patients receiving radiotherapy at some point in their cancer journey (access rate), which was estimated at 52% [3]. Although the NRAG model has been instrumental in providing evidence of radiotherapy under provision, it has proven difficult for clinicians and local commissioning groups to apply the model at a regional level, just as the RCR report would have predicted. Independent of any differences in clinical practice among radiation oncologists across the country, local variation in radiotherapy demand is driven by differences in population demographics and age distribution, co-morbidity, disease incidence and variation in the diagnostic and surgical pathways leading to radiotherapy treatment. It clear that a national ‘best fit’ model cannot provide a good fit for commissioning and service provision at the local level.

The Malthus Programme: Developing Radiotherapy Demand Models for Breast and Prostate Cancer at the Local, Regional and National Level

AIMS The Malthus Programme has delivered a tool for modelling radiotherapy demand in England. The model is capable of simulating demand at the local level. This article investigates the local and regional level variation in predicted demand with respect to Breast and Prostate cancer, the two tumour types responsible for the majority of radiotherapy treatment workload in England. MATERIALS AND METHODS Simulations were performed using the Malthus model, using base population incidence data for the period from 2007-2009. Simulations were carried out at the level of Primary Care Trusts, Cancer Networks, and nationwide, with annual projections for 2012, 2016 and 2020. Benchmarking was undertaken against previously published models from the UK, Canada and Australia. RESULTS For breast cancer, the fraction burden for 2012 varied from 5537 fractions per million in Tower Hamlets PCT to 18 896 fractions per million in Devon PCT (national mean - 13 592 fractions per million). For prostate cancer, the fraction burden for 2012 varied from 4874 fractions per million in Tower Hamlets PCT to 23 181 fractions per million in Lincolnshire PCT (national mean - 15 087 fractions per million). Predictions of population growth by age cohort for 2016 and 2020 result in the regional differences in radiotherapy demand becoming greater over time. Similar effects were also observed at the level of the cancer network. CONCLUSIONS Our model shows the importance of local population demographics and cancer incidence rates when commissioning radiotherapy services.

Quantifying uncertainty in radiotherapy demand at the local and national level using the Malthus model.

The Malthus programme produces a model for the local and national level of radiotherapy demand for use by commissioners and radiotherapy service leads in England. The accuracy of simulation is dependent on the population cancer incidence, stage distribution and clinical decision data used by the model. In order to quantify uncertainty in the model, a global sensitivity analysis of the Malthus model was undertaken. As predicted, key decision points in the model relating to stage distribution and indications for surgical or non-surgical initial management of disease were observed to yield the strongest effect on simulated radiotherapy demand. The proportion of non-small cell lung cancer patients presenting with stage IIIB/IV disease had the largest effect on fraction burden in the four most common cancer types treated with radiotherapy, where a 1% change in stage IIIb/IV disease yielded a 1.3% change in fraction burden for lung cancer patients. A 1% change in mastectomy rate yielded a 0.37% change in fraction burden for breast cancer patients. The model is also highly sensitive to changes in the radiotherapy indications in colon and gastric cancer. Broadly, the findings of the sensitivity analysis mirror those previously published by other groups. Sensitivity analysis of the local-level population and cancer incidence data revealed that the cancer registration rate in the 50-64 year female population had the highest effect on simulation results. The analysis reveals where additional effort should be undertaken to provide accurate estimates of important parameters used in radiotherapy demand models.

Using the Malthus programme to predict the recruitment of patients to MR-linac research trials in prostate and lung cancer

In this study, we used evidence-based mathematical modelling to predict the patient cohort for MR-linac to assess its feasibility in a time of austerity. We discuss our results and the implications of evidence-based radiotherapy demand modelling tools such as Malthus on the implementation of new technology and value-based healthcare.

Mathematical Modelling for Patient Selection in Proton Therapy

Proton beam therapy (PBT) is still relatively new in cancer treatment and the clinical evidence base is relatively sparse. Mathematical modelling offers assistance when selecting patients for PBT and predicting the demand for service. Discrete event simulation, normal tissue complication probability, quality-adjusted life-years and Markov Chain models are all mathematical and statistical modelling techniques currently used but none is dominant. As new evidence and outcome data become available from PBT, comprehensive models will emerge that are less dependent on the specific technologies of radiotherapy planning and delivery.

The Malthus Project - updated predictions of national radiotherapy demand to 2030

Purpose: To evaluate the significance of fractionated administration of thalidomide combined with γ-ray irradiation in terms of local tumor response and lung metastatic potential, referring to the response of intratumor quiescent (Q) cells. Materials/methods: B16-BL6 melanoma tumor-bearing C57BL/6 mice were continuously given 5-bromo-2’deoxyuridine (BrdU) to label all proliferating (P) cells. The tumor-bearing mice then received γ-ray irradiation after thalidomide treatment through a single or 2 consecutive daily intraperitoneal administrations up to a total dose of 400 mg/kg in combination with an acute hypoxia-releasing agent (nicotinamide, 1,000 mg/kg, intraperitoneally administered) or mild temperature hyperthermia (MTH, 40 centigrade for 60 minutes). Immediately after the irradiation, cells from some tumors were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (= P + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumor-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated. Results: Thalidomide raised the sensitivity of the total cell population more remarkably than Q cells in both single and daily administrations. Daily administration of thalidomide elevated the sensitivity of both the total and Q cell populations, but especially the total cell population, compared with single administration. Daily administration, especially combined with MTH, decreased the number of lung metastases. Conclusions: Daily fractionated administration of thalidomide in combination with γ-ray irradiation was thought to be more promising than single administration because of its potential to enhance local tumor response and repress lung metastatic potential.

OC-0332: Modelled effects of hypofractionation on radiotherapy demand in England

Conclusion: Most of the modulation indexes proposed in the literature are related to the robustness and modulation of a plan. However, none of them has been conceived to appropriately predict the interplay effect in lung SABR. MIt has been found to be the only published index capable of detecting failing plans. MIt and PUMA have the same specificity since both detected all of the failing plans. However, PUMA has a greater accuracy and sensitivity.

PD-0564 THE MALTHUS PROGRAMME : A NEW MODEL FOR SIMULATION OF EVIDENCE-BASED RADIOTHERAPY DEMAND IN ENGLAND

Aim In 2007, the National Radiotherapy Advisory Group (NRAG) issued a report with national targets for radiotherapy capacity based on cancer incidence and best clinical practice1. The model specified a national target of 54,000 fractions per million by 2016, and an access rate (percentage of cancer patients receiving radiotherapy treatment) of 52%. Whilst the model formed the basis of targets within the National Cancer Plan, it is difficult to apply the model at a local level, due to the variation in underlying population demographics and a 2.5 fold variation in cancer incidence within the country.