A clinical trial testing the efficacy of PDT in preventing amputation in diabetic patients

Abstract

The feet of diabetic patients continue to be an unsolved problem in medicine. Uncontrolled neuropathy, ulceration and infection usually lead to amputation and presently there is no effective and reliable method that can be used to provide an efficient cure. Overall improvement in the salvage strategies, based on comprehensive pre-clinical evaluation, debridement, antibiotic therapy and follow up, has shown improvements in certain hospital settings, but the general picture for patients with diabetic foot is to have some sort of amputation, especially in underserved populations. It is clearly necessary to develop novel treatment strategies for this worldwide health problem. Photodynamic therapy (PDT) is a treatment modality that uses light to generate in situ reactive oxygen species, which can cause cell death. PDT can be used to treat several diseases, including foot infections that do not respond well to antibiotic therapy. There are several characteristics of PDT that make it potentially ideal to treat diabetic feet: the photosensitizer is non-toxic in the dark, but after illumination it becomes a very efficient antimicrobial agent with topical use, and it can regenerate small bones, such as the phalanges. However, PDT is still not used in clinical practice to treat diabetic feet. Therefore, we decided to perform a clinical study to prove that PDT is an effective method to avoid amputation of infected diabetic feet. An inexpensive PDT protocol was developed and applied to 18 patients with osteomyelitis, classified as Grade 3 on the Wagner scale. Only one of these patients suffered amputation. At least two of them were cured from resistant bacteria strains without intravenous antibiotic therapy. In the control group of 16 patients, all of them ended up suffering amputation. The rate of amputation in the PDT group was 0.029 times the rate in the control group and the difference is clearly statistically significant (p=0.002).

Keywords: Antimicrobial; Clinical; Diabetes; Diabetic foot; Osteomyelitis; PACT; PDT; Singlet oxygen; Wagner scale.