PET-CT surveillance for advanced head and neck cancer : a cost-effective alternative to planned neck dissection?

Background: Despite controversy, planned neck dissection (ND) remains standard treatment for patients with locally advanced head and neck squamous cell carcinoma after radical chemo-radiotherapy. FDG-PET-CT scanning has demonstrated high negative predictive values for persistent disease, and could thereby enable low risk patients to be spared from unnecessary surgery. Evidence of the cost-effectiveness of PET-CT surveillance strategies is limited however, and no evaluations have yet been conducted from a UK perspective. Methods: An economic evaluation was conducted to assess the lifetime cost-effectiveness of PET-CT surveillance versus planned ND from a UK secondary care perspective. Cost and health outcomes associated with the initial 6-month treatment period (CRT +/- ND) were derived from individual data on 564 patients from a recent UK multicentre randomised controlled trial (PET-Neck). Subsequent outcomes were derived using a constructed Markov model to track patients through four health states: disease-free, local recurrence, distant recurrence and dead. Model inputs were derived from trial data and literature sources. Results: PET-CT surveillance results in a lifetime cost saving of -£1,485 (95% CI: -2,815 to 159) and health gain of +0.13 (95% CI: -0.49 to +0.79) quality-adjusted life-years (QALYs) per patient. The intervention therefore dominates standard care, being more effective and less costly, with an incremental net benefit (INB) of +0.21 QALYs (95% CI: -0.41 to +0.85). At a willingness-to-pay per QALY threshold of £20,000, PET-CT is associated with a 75% probability of being cost-effective, dropping to 68% at a £100,000/QALY threshold. The intervention remained cost-effective when considering a broader NHS and personal social services perspective; however, uncertainty around the mean cost-effectiveness values was wide. Conclusions: PET-CT surveillance appears to be cost-effective, leading to expected lifetime cost savings and a marginal health increment. There is significant uncertainty in the longer term which may warrant additional survivor-ship research