Effect of the combination of photobiomodulation therapy and the intralesional administration of corticoid in the preoperative and postoperative periods of keloid surgery: A randomized, controlled, double-blind trial protocol study

Abstract

Keloid scars are characterized by the excessive proliferation of fibroblasts and an imbalance between the production and degradation of collagen, leading to its buildup in the dermis. There is no “gold standard” treatment for this condition, and the recurrence is frequent after surgical procedures removal. In vitro studies have demonstrated that photobiomodulation (PBM) using the blue wavelength reduces the proliferation speed and the number of fibroblasts as well as the expression of TGF-β. There are no protocols studied and established for the treatment of keloids with blue LED. Therefore, the purpose of this study is to determine the effects of the combination of PBM with blue light and the intralesional administration of the corticoid triamcinolone hexacetonide on the quality of the remaining scar by Vancouver Scar Scale in the postoperative period of keloid surgery. A randomized, controlled, double-blind, clinical trial will be conducted involving two groups: 1) Sham (n = 29): intralesional administration of corticoid (IAC) and sham PBM in the preoperative and postoperative periods of keloid removal surgery; and 2) active PBM combined with IAC (n = 29) in the preoperative and postoperative periods of keloid removal surgery. Transcutaneous PBM will be performed on the keloid region in the preoperative period and on the remaining scar in the postoperative period using blue LED (470 nm, 400 mW, 4J per point on 10 linear points). The patients will answer two questionnaires: one for the assessment of quality of life (Qualifibro-UNIFESP) and one for the assessment of satisfaction with the scar (PSAQ). The team of five plastic surgeons will answer the Vancouver Scar Scale (VSS). All questionnaires will be administered one, three, six, and twelve months postoperatively. The keloids will be molded in silicone prior to the onset of treatment and prior to excision to assess pre-treatment and post-treatment size. The same will be performed for the remaining scar at one, three, six, and twelve months postoperatively. The removed keloid will be submitted to histopathological analysis for the determination of the quantity of fibroblasts, the organization and distribution of collagen (picrosirius staining), and the genic expression of TGF-β (qPCR). All data will be submitted to statistical analysis. Trial registration: This study is registered in ClinicalTrials.gov (ID: NCT04824612).

Inhibition of keloid by 32P isotope radiotherapy through suppressing TGF-β/Smad signaling pathway

“…In the process of skin healing, fibroblasts proliferate excessively and secrete a large amount of extracellular matrix, and cell apoptosis is delayed and degradation is insufficient, and local microvascular formation is increased, many factors promote its gradual formation of keloid [ 17 , 18 ]. 32 P released β-rays can directly or indirectly ionize and destroy DNA molecular structure, inhibit cell division and proliferation, inhibit fibroblast migration, proliferation and collagen synthesis and secretion, weaken immune cell function and reduce dysfunctional blood vessels, strongly inhibit inflammatory reaction, and can also effectively induce cell apoptosis and reduce TGF-β [ 19 ], Reduce the synthesis of extracellular matrix and collagen fiber, thus inhibiting the formation of keloid.…”

Comparison of Pulsed and Continuous Wave Diode Laser at 940 nm on the Viability and Migration of Gingival Fibroblasts

“…NIR (near infra-red) treatments have been noted to increase Cytochrome c oxidase activity, especially in the 10 Hz pulsed group, and transiently increase ATP and reactive oxygen species by disrupting the electron transport chain within the mitochondria (25). Besides wound healing, the effects of PBM on collagen synthesis and turnover could be utilized for other treatments such as hereditary gingival fibromatosis or keloid formation and hypertrophic scars (60)(61)(62)(63). Moreover, there has been tremendous recent progress on the evidence supporting PBM treatments in oncotherapy-associated oral mucositis (64,65).…”

Photobiomodulation in clinical practice

“…Blue light, in particular, is reported to have an inhibitory effect on fibroblasts and TGF-β when administered at a higher energy density (up to 640 J/cm2). 211 Some studies have actually reported the benefits of PBM in the progress of postoperative healing of scars from different types of interventions, demonstrating the safety and efficacy of such therapy.…”

“…To be monitored in this sense will be the progress of the study proposed by Jefferson André Piresi et al entitled "Effect of the combination of PBM therapy and the intralesional administration of corticoid in the preoperative and postoperative periods of keloid surgery: A randomized, controlled, double-blind trial protocol study" whose prospectus was published on PLoS ONE on February 15, 2022 and registered on ClinicalTrials.gov (ID: NCT04824612). 211 The purpose of that study is to fill the absence of randomized double-blind trials on the subject of preventing keloid formation through the use of PBM. Specifically, the study was designed with a study group composed of 29 patients to whom PBM will be applied combined with the administration of intralesional corticosteroids in the preoperative phase and then, after surgical removal of the keloid, the PBM alone in the post-operative period using a blue LED light (470 nm, 400 mW, 4J per point on 10 linear points).…”