40 Intensity-modulatedradiotherapyKCE reports 62 7.2.3 Assumptions for IMRT delivery 4000 3500 3000 2500 2000 1500 1000 500 0 The principal therapeutic assumption we made is that patients being treated with IMRT would otherwise, i.e. in absence of IMRT as a therapeutic choice, have been treated with 3DCRT (prostate cancer, head and neck cancer) or 2DRT (breast cancer) f . The main implication of this assumption is that alternative treatment shifts, e.g. from patients who would have been treated (exclusively) with brachytherapy for prostate cancer, are excluded from our analysis. Given the absence of data on the clinical outcome of therapeutic substitution between IMRT and brachytherapy in prostate cancer patients, it was deemed judicious to approach the introduction of IMRT as a “ceteris paribus” transition from patients treated with 3DCRT to patients treated with IMRT. This assumption is corroborated by Figure 4, indicating no apparent substitution effects have been playing that would divert patient treatment preferentially to IMRT. It would also seem that the newly introduced regulation on the reimbursement of investment and operational costs from April 2005 on has not considerably influenced the delivery of brachytherapy. As the new regulation is solely based on the number of deliveries through categories 1-4 it tends to favour the implementation of brachytherapy (categories 6-10) less than the former regulation did. Figure 4 Brachytherapy versus IMRT under article 18: number of treatment courses 2018 114 2368 340 External beam radiotherapy uptake as a percentage of newly diagnosed patients by tumour type was derived from CCORE 2003 105 . This publication sets “optimal”, i.e. evidence-based, radiotherapy uptake rates through a systematic review for a comprehensive range of cancers with a view to facilitating further planning efforts for external radiotherapy infrastructure needs. These data have already been applied internationally in estimating external radiotherapy investment costs 106 107 98 . Table 13 summarizes the uptake rates that are most pertinent to our analysis. Table 13 Uptake rate for external beam radiotherapy by type of cancer Tumour type Proportion of all cancers Patients receiving RT (%) Breast 13% 83% Prostate 12% 60% Head and Neck 4% 78% f At present, breast cancer patients are excluded from reimbursement for 3DCRT (see appendix 6). 2570 Article 18: Exclusive Treatment With Brachytherapy (categories 7-10) Article 18: Exclusive Treatment With IMRT 2002 2003 2004 2005 463 3471 712
KCE reports 62 Intensity-modulatedradiotherapy 41 Overall, an optimal external radiotherapy rate of 52.3% is put forth for newly diagnosed cancer patients. Adding 25% of cancer patients requiring re-treatment through external radiation (regardless of tumour type), an optimal level of 65.4 treatment courses per one hundred cancers is assumed 105 . Comparing the number of external RT treatment courses for 2002-2003-2004 (see appendix 6) to the extrapolated cancer incidence for the same year, we obtain percentages of respectively 45.6%, 46.1% and 47.5% for Belgium. Although the uptake rates are persistently below the rate put forth by CCORE 2003, a trend towards a higher uptake rate is observed (geometric average for year-to-year growth rates of 1,02%). In applying the average geometric growth rate for 2002-2004 we can extrapolate uptake rates for 2005 and 2006 of respectively 48.03% and 48.52% (see Figure 5). The lower uptake rates for Belgium may imply alternative therapeutic interventions are preferred over external radiotherapy or indicate differences in average numbers of fractions per course, etc. Furthermore, current treatment practice in Europe has been reported to be “about 45-55%” of new cancer patients receiving external radiation 108 , putting the CCORE optimal uptake rate at the upper end of estimated current treatment practices. In order to assess the short-term budget impact of IMRT we will correct RT uptake rates in our model with year-to-year downward correction factors ranging from of 0.7 (2002) to 0.74 (2006) as this would be more in line with the actual Belgian situation (see Figure 5). These correction factors were obtained by dividing the actual RT uptake rates for Belgium by the optimal uptake rate of 65.4% estimated by CCORE 2003. Figure 5 Overall RT uptake rates for Belgium Extrapolated rates (“e”) for 2005 and 2006 The eventually applied RT uptake rates and resulting patient numbers can be found in Table 14 and Table 15 (see also appendix 10). In our model we will additionally explore the impact the higher CCORE uptake rates have on our endpoint as well as the higher uptake rate of 80% reported for breast cancer patients in Belgium 59 .