Hydrogel Spacers for Patients with Prostate Cancer: A Review of Clinical Effectiveness and Cost-Effectiveness

Key Message

Three systematic reviews, one randomized controlled trial (described within two eligible reports), seven cohort studies, two economic evaluations, and three guidelines were included in this report. Hydrogel spacers were effective in increasing the distance between the prostate and the rectum, and in reducing the radiation dose to the rectum while delivering radiation to the prostate in patients with localized prostate cancer. However, two systematic reviews reported that the clinical benefits were not significant, and were therefore uncertain. One systematic review developed for a health technology assessment did not recommend the routine use of hydrogel spacers for prostate cancer, in consideration of the high costs for their patients. In contrast, three-year follow-up results of a randomized controlled trial indicated that hydrogel spacers were associated with improvements in bowel, urinary and sexual quality of life outcomes. Despite uncertainty, one cost-effectiveness analysis concluded that hydrogel spacers were cost-effective at a willingness to pay threshold of $100,000 in the United States in 2018. One decision analysis concluded that spacer use results in a marginal cost increase and a significant reduction in rectal toxicity. For patients receiving high-dose stereotactic body radiotherapy, the use of hydrogel spacers was found to be cost-effective. The guidelines by Cancer Care Ontario, the National Comprehensive Cancer Network, and the National Institute for Health and Care Excellence recommended the use of hydrogel spacers to reduce rectal toxicity and improve quality of life.