Does hyperbaric oxygen reduce the chance of the development of osteoradionecrosis following surgery in an irradiated mandible? A study protocol.

1. Study protocol only and so no results at this time.

Citation/s: Shaw R, Butterworth C, Tesfaye B, Bickerstaff M, Dodd S, Smerdon G, Chauhan S, Brennan P, Webster K, McCaul J, Nixon P. HOPON (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis): a randomised controlled trial of hyperbaric oxygen to prevent osteoradionecrosis of the irradiated mandible: study protocol for a randomised controlled trial. Trials. 2018 Dec;19(1):22-32.

Lead author's name and email: Richard Shaw Three-part Clinical Question: For patients at risk of developing osteoradionecrosis of the mandible, does a course of hyperbaric oxygen, compared to normal care alone, result in a lower rate of development of this complication?

Search Terms: Osteoradionecrosis, preventative, radiotherapy

    • The Study:

Single-blinded concealed randomised controlled trial with intention-to-treat.

The Study Patients: Adult patients with a history of radiotherapy to the mandible (>50Gy) needing either dental extractions or implants.

Control group (N = 110): Standard treatment including clorhexidine mouthwashes for five days postoperatively and amoxicillin immediately pre-op and for five days postoperatively

Experimental group (N = 111): As above plus 100% oxygen breathing at 2.4 ATA between 80 and 90 minutes daily. 20 sesssions pre-op and 10 post-op.

    • The Evidence:
Outcome Time to Outcome Control
Event Rate
Event Rate
Risk Reduction
Risk Reduction
Diagnosis of ORN Six months
^ 95% CIs:
Diagnosis of ORN 12 months
^ 95% CIs:
    • Comments:

1. Stratified randomisation by centre and in randomly-sized blocks.

2. The primary outcome will be assessed by blinded investigators

3. Patients are eligible if >50Gy was administered even though the authors suggested the group who received >60Gy have been shown to be at high risk.

4. Secondary outcomes include QoL by head and neck questionnaire, pain, acute postoperative symptoms and adverse effects.

5. Study is powered (80%) to find a difference between groups if the rate of ORN is 5% with HBO and 18.5% in the control arm. This seems a very high rate in the control arm and may well be above the minimum clinically important difference. (221 patients planned in total).

6. Interim analyses planned by an independent monitoring committee.

7. Authors considered a sham control but decided against this because of financial pressure as well as doubts about the feasibility of the patents remaining blinded (despite evidence to the contrary in the literature). The primary outcome is, however, a hard outcome made by blinded experts.

8. A potential bias is identified due to earlier surgery after randomisation to the control group.

Appraised by: Michael Bennett; Friday, 28 December 2018

Kill or Update By: December 2019