CiteULike: The relative costs of proton and X-ray radiation therapy.

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http://www.citeulike.org/user/proportional/article/1442705

AIM: To

study the costs of intensity-modulated proton therapy and intensity-modulated

X-ray therapy with the particular goal of understanding their relative

differences. To analyse the ratio of the cost per fraction of proton therapy to

the cost per fraction of X-ray therapy. MATERIALS AND METHODS: We have used a

computer spreadsheet tool in which a large number (typically 130) of input

parameters characterizing a particular therapeutic modality can be stored. From

these parameters a number of derived variables are computed, and from these

derived variables the costs of sub-systems, the entire facility, running costs

and cost per fraction and per treatment can be computed. The sensitivity of any

given variable (e.g. cost/fraction) to any given parameter (e.g. set-up time)

can be explored, together with an estimate of the associated confidence

interval. The costs of facility construction and facility operation are

considered separately. Key data for the input variables regarding the cost of

the therapy equipment (a dominant cost for proton beam therapy) were provided

by four commercial vendors. Other costs, such as costs for building

construction and shielding or personnel costs, are much more standard and our

estimates were primarily based on practical experience. We considered two

scenarios: (1) both facilities operating under current conditions; and (2)

future facilities where foreseeable improvements in efficiency and a 25%

reduction in the cost of the proton equipment were assumed. RESULTS: The

construction cost of a current two-gantry proton facility, complete with the

equipment, was estimated at 62,500 kEE and of a two-linac X-ray facility at

16,800 kEE. In the case of proton therapy the cost of operation of the facility

was found to be dominated, by the business cost (42%--primarily the cost of

repaying the presumed loan for facility construction), personnel costs (28%)

and the cost of servicing the equipment (21%). For X-ray therapy, the cost of

operation was seen to be dominated by the personnel cost (51%) and the business

costs (28%). The costs per fraction were estimated to be 1.025 kEE for protons

and 0.425 kEE for X-rays--for a ratio of costs of 2.4 +/- 0.35 (85%

confidence). In a future facility these costs could be reduced to 0.65 kEE and

0.31 kEE respectively, leading to a ratio of costs of 2.1. A number of further

improvements could be imagined which could reduce the ratio of costs by some

20%. If, however, the initial capital investment were 'forgiven,' so that the

operating costs need not repay the investment, both the costs and the ratio of

costs would be significantly less. We estimate that, under this condition, the

future costs of proton and X-ray therapies would be 0.37 kEE and 0.23 kEE,

respectively, for a cost-per-fraction ratio of 1.6. This ratio could also be

susceptible to a further 20% reduction. CONCLUSIONS: Sophisticated (i.e.,

intensity-modulated) proton therapy is now, and is likely to continue to be,

more expensive than sophisticated (i.e., intensity-modulated) X-ray therapy.

The ratio of costs is about 2.4 at present and could readily come down to 2.1,

and even, perhaps 1.7 over the next 5 to 10 years. If recovery of the initial

investment is not required, the ratio of costs would be much lower, in the

range of 1.6 to 1.3. The question of whether the greater cost of proton beam

therapy is clinically worthwhile is a cost-effectiveness issue. The goal of

this study is to contribute to the former arm of this comparison.