Ice chips in the chair for every bolus fluorouracil and high-dose melphalan infusion

The evidence. The 2015 Cochrane review included 14 randomised trials with 1,280 participants, all at high risk of bias, mostly in chemotherapy rather than head and neck radiotherapy. For adults receiving fluorouracil-based chemotherapy for solid cancers, oral cryotherapy probably reduces oral mucositis of any severity (risk ratio 0.61, 95 per cent confidence interval 0.52 to 0.72, five studies, moderate-quality evidence), with a number needed to treat of 4, and probably reduces severe mucositis (risk ratio 0.40, 0.27 to 0.61), number needed to treat 6. For high-dose melphalan before haematopoietic stem cell transplantation, severe mucositis is probably reduced (risk ratio 0.38, 0.20 to 0.72). Adverse effects were minor and rare.

The guideline. The 2020 MASCC/ISOO mucositis guideline states: "The panel recommends using 30 min of oral cryotherapy to prevent OM in patients receiving bolus 5-FU CT during the infusion of the CT" and "recommends using oral cryotherapy to prevent OM in patients undergoing autologous HSCT when the conditioning includes high-dose melphalan."

The limits. The rationale rests on a short peak in drug level, which a continuous infusion or a daily tablet does not produce, so the recommendation covers bolus fluorouracil and high-dose melphalan and nothing wider. OnCo found no survey or audit of how often eligible patients are offered it, so the gap between recommendation and practice is not measured; the tier records strong evidence for an intervention that costs a cup of ice.