Cost-effectiveness of intensity-modulated radiotherapy in oropharyngeal cancer

Intensity-modulated radiotherapy (IMRT) is an advanced radiation technique that is particularly suited to treating head and neck cancers because it can conform a high dose to the target volume while preserving the tissue function of neighbouring structures. The objective of this study was to compare the cost and effectiveness of IMRT with three-dimensional conformal radiotherapy (3DCRT) for the treatment of locally advanced oropharyngeal cancer.

We developed a Markov model to estimate the incremental cost per quality-adjusted life-year (QALY) gained by IMRT from the perspective of the Ministry of Health. The costs of IMRT and 3DCRT were estimated through activity-based costing, incorporating input from radiation oncologists, physicists and radiation therapists. We obtained clinical effectiveness estimates from published studies and calculated the number needed to treat to avoid a case of severe long-term xerostomia using data from a randomised controlled trial.

The delivery of IMRT produced 0.48 more QALYs than 3DCRT at an additional cost of $2447 (QALY and costs discounted at 5% a year), yielding an incremental cost-effectiveness ratio of $5084 per QALY gained. The cost-effectiveness of IMRT was sensitive to the costs of radiotherapy and the effect of IMRT on health-related quality of life. The cost of IMRT will probably decrease with the addition of volumetric modulated arc therapy, an increasingly used technology, because volumetric modulated arc therapy reduces treatment time. We need to treat less than two patients with IMRT to avoid a case of severe, long-term xerostomia (dry mouth), and the incremental cost to avoid a case of severe, long-term xerostomia was $4532.

In the treatment of locally advanced oropharyngeal carcinoma, the IMRT strategy appears to be cost-effective when compared with 3DCRT.