Complete restoration of refractory mandibular osteoradionecrosis by prolonged treatment with a pentoxifylline-tocopherol-clodronate combination (PENTOCLO): a phase II trial

Abstract

Purpose: Osteoradionecrosis (ORN) is a nonhealing wound of the bone that is difficult to manage. Combined treatment with pentoxifylline and vitamin E reduces radiation-induced fibrosis and ORN with a good prognosis. We previously showed that the combination of pentoxifylline and vitamin E with clodronate (PENTOCLO) is useful in healing sternocostal and some mandibular ORN. Is PENTOCLO effective in ORN of poor prognosis?

Methods: 54 eligible patients previously irradiated for head and neck cancer (among 72 treated) a mean 5 years previously received exteriorized refractory mandibular ORN for 1.4 ± 1.8 years, mainly after local surgery and hyperbaric oxygen had been ineffective. The mean length of exposed bone (D) was 17 ± 8 mm as primary endpoint, and the mean Subjective, Objective, Management, and Analytic evaluation of injury (SOMA) score was 16 ± 4. Between August 2000 and August 2008, all patients were given daily oral PENTOCLO: 800 mg pentoxifylline, 1,000 IU vitamin E, and 1,600 mg clodronate 5 days per week alternating with 20 mg prednisone and 1,000 mg ciprofloxacin 2 days per week. The duration of treatment was related to consolidated healing.

Results: Prolonged treatment (16 ± 9 months) was safe and well tolerated. All patients improved, with an exponential progressive--(f[t] = a.exp(-b.t)--and significant (p < 0.0001) reduction of exposed bone (D), respectively (months): D(2) -42%, D(4) -62%, D(6) -77%, D(12) -92%, and D(18) -96%, combined with iterative spontaneous sequestrectomies in 36 patients. All patients experienced complete recovery in a median of 9 months. Clinical improvement was measured in terms of discontinuation of analgesics, new fracture, closed skin fistulae, and delayed radiologic improvement: SOMA(6) -64%, SOMA(12) -89%, and SOMA(30) -96%.

Conclusion: Long-term PENTOCLO treatment is effective, safe, and curative for refractory ORN and induces mucosal and bone healing with significant symptom improvement. These findings will need to be confirmed in a randomized trial.