SCOTTSDALE, ARIZ. – A home humidification device can reduce the symptom burden of mucositis in patients undergoing radiation for head and neck cancers, but the technology only works when patients actually use it, reported investigators at the Multidisciplinary Head and Neck Cancer Symposium.
In a randomized phase III trial, patients assigned to daily humidification of the mouth and throat beginning on the first day of radiation had a 45% reduction in risk for acute hospitalization and had about half the symptom-related hospital days of patients who did not receive daily humidification, reported Dr. Andrew Macann from Auckland (New Zealand) City Hospital.
However, compliance with the humidification protocol was spotty, with only 42% of patients assigned to the therapy using it according to study protocol, Dr. Macann noted.
"The efficacy signals were seen across clinician-reported, independent, and patient-reported outcomes, and although in the main these signals were seen in the per-protocol analysis, the result which is perhaps most influential in considering whether domiciliary humidification could be cost effective, was the reduction in inpatient hospital days, where there was significant reduction in both the intention-to-treat and per protocol analyses," he said at the symposium, cosponsored by the American Society for Radiation Oncology and the American Society of Clinical Oncology .
The device used in the study was a humidifier/flow generator with a plastic face apparatus that delivered 44 mg of water per liter of air at a rate of 30 L/min. The flow was designed to slightly exceed inspiratory flow so that there was no entrainment of nonhumidified air.
In the trial, conducted by the Trans Tasman Radiation Oncology Group, 210 patients with cancers of the nasopharynx, oropharynx, oral cavity, larynx or hypopharynx were randomly assigned to receive humidification plus the institutional standard of care for mucositis management, or standard of care alone. Patients assigned to humidification were supposed to continue on the protocol until resolution of the ulcerative component of clinical mucositis.
A total of 103 patients assigned to humidification and 100 controls were available for the intention-to-treat (ITT) analysis.
Humidification compliance was electronically recorded, with full compliance consisting of more than 4 hours of daily use. The investigators calculated compliance ratios based on the number of full compliance days divided by the total days from the start of therapy to resolution of ulcerative mucositis. They determined high compliance to be a ratio greater than 0.67, and medium compliance to be a ratio of 0.34-0.66. High and medium compliers (23 and 20 patients, respectively) were included in the per-protocol analysis.
Although the humidification protocol did not meet the primary endpoint (area under the curve for a clinical mucositis score of 2 or greater according to Common Terminology Criteria for Adverse Events) in either the ITT or per-protocol analysis, there was a significant reduction in clinician-assessed functional mucositis symptom burden among the compliant patients (P = .009).
Additionally, total days in hospital were significantly lower among patients on the experimental protocol in both the ITT and per-protocol analyses. Control patients spent a geometric mean 4.10 days in hospital compared with 2.32 in ITT (P = .017), and 1.65 in per-protocol (P = .006). The investigators calculated that all patients treated with humidification spent only 57% of the hospital days of controls, and that compliant patients spent only 40% of those days.
Compliant patients were also significantly less likely than controls to require a feeding tube, with an odds ratio for never needing a tube of 2.50 (P = .035).
Patient-reported impression of symptom burden as rated on the McMaster University Head and Neck Questionnaire trended toward favoring the humidification protocol but there were no significant differences between the groups.
Simple strategies such as humidification can add value to head and neck cancer therapy, commented Dr. Paul M. Harari of the University of Wisconsin, Madison.
"I would love to see this humidification developed in a way that would be more compliant for patients, because I have no doubt that it could be valuable," he said.
The study was funded by the New Zealand Ministry of Science and Innovation, Fisher and Paykel Healthcare, Baxter Healthcare, and Auckland Hospital Charitable Trust. Dr. Macann and Dr. Harari reported having no conflicts of interest.