Variations in IMRT demand and delivery across England

Abstract

Purpose or Objective Intensity Modulated Radiotherapy (IMRT) is a key radiotherapy (RT) technique used for radical treatments. A 2015 report1 from England suggested that 51.8% of radical RT patients should be treated with IMRT. However, there are variations in the profile of cancer throughout England. This will result in variations in the demand for IMRT and therefore 51.8% may not be applicable at local level. Delivery of IMRT may also vary between RT centres. The English Cancer registries record delivered RT data, including which treatments were IMRT. Here, we compare the recorded IMRT delivered data to a local-level IMRT demand simulations. Material and Methods The future IMRT predictions from the 2015 report were encoded into the Malthus Model2 for every IMRT relevant cancer site. Malthus contains local-level population, incidence and stage presentation data. Malthus simulated the IMRT demand for every clinical commissioning group (CCG) in England. The recorded IMRT delivered data is also at CCG level and was sourced from Public Health England. The recorded IMRT data was converted to a percentage of the simulated demand. A heat map of the results was created for England in Tableau software3. The postcode location of every main RT centre in England was obtained and plotted on the heat map, including information on the number of linacs registered at the centre. Breast IMRT was excluded from the analysis, as it could potentially distort the data, due to current questions around inverse/forward planned IMRT and service targets1. Results There is variation in simulated demand for IMRT across England, ranging from 44.7% to 56.5% of radical RT patients. There is also variation in recorded IMRT delivery, ranging from 21% to 67%. When comparing a CCG’s recorded IMRT to its simulated demand the results range from 55% to 164%. Figure 1 shows the results of the comparison for every CCG in England alongside RT centre location and size information. Conclusion The combination of the future demand figures from the 2015 IMRT report and the Malthus model has produced the regional variations in IMRT demand. The heat map of the comparison of recorded IMRT delivery data to the locallevel demand, highlights regions within England which may be under providing, or over providing, IMRT. These areas should be investigated in detail to identify the reasons for these differences. There may be non-service factors driving the differences, such as data and recording inaccuracies, incidence fluctuations or comorbidities. These are factors which are not currently included in the Malthus model.