CyberKnife Cost-Effective in the Long-Term

Debra Wood, RN

April 2011, Vol 2, No 2 - Genitourinary Cancers Symposium

Orlando, FL—Although the cost of CyberKnife to treat prostate cancer is initially higher than surgery—an equally effective therapy—patients experience a better quality of life with CyberKnife than with other treatment modalities and have lower lifetime costs compared with radiation and proton therapies.

CyberKnife uses image-guided stereotactic radiosurgery to target tumors and requires fewer visits than needed with external beam radiation. Researchers at Innovus, San Francisco, used a Markov model to compare payer and societal costs associated with surgery, CyberKnife,intensity-modulated radiation therapy (IMRT), and proton therapy and their related adverse events in patients aged ≥65 years with prostate cancer. Societal costs include items associated with a productive life and paid for by the individual or family.

“Surgery is cheaper, but is CyberKnife better?” asked Anju Parthan, PhD, Senior Project Manager for Health Economics & Outcomes Research at Innovus. “It costs more, but you can have improved quality of life,” she commented.

All possible combinations of gastrointestinal, genitourinary, and sexual dysfunction long-term toxicities were included. Toxicity probabilities were obtained from the pooled results of multiple studies. Costs were assigned based on published sources.

The model projected lifetime costs and quality-adjusted life-years (QALYs) for each treatment. Total lifetime costs from a payer perspective were:

  • $25,904 for CyberKnife
  • $22,295 for surgery
  • $38,915 for IMRT
  • $58,100 for proton therapy.

The incremental cost per QALY gained with CyberKnife over surgery was $9200 from a payer perspective and $4800 from a societal perspective.

Dr Parthan said, “$9200 is a small dollar value in the threshold of what payers are willing to pay for quality of life.” That threshold “is in the $50,000 to $100,000 range in the United States.”

At a threshold of $50,000 per QALY, CyberKnife was cost-effective from a payer perspective 84% of the time.

Dr Parthan added that a head-tohead trial ideally would be used to determine the most cost-effective treatment, but limitations associated with randomization do not make that pos sible.

Therefore, the research company conducted a sensitivity analysis and concluded that CyberKnife is a costeffective strategy compared with surgery, and that its costs are less, with better quality of life, than external beam radiation therapy or proton therapy.