# Potential role of photobiomodulation as a prevention and treatment strategy for radiation induced fibrosis: a review of effectiveness and mechanisms

## TL;DR

This review explores how photobiomodulation therapy may help prevent and treat radiation-induced fibrosis, a common side effect of cancer treatment.

## Contribution

The paper provides a scoping review of PBMT's potential for RIF, summarizing its effects and mechanisms based on preclinical and clinical studies.

## Key findings

- PBMT shows beneficial effects on fibrosis at the cellular level in preclinical studies.
- Clinical studies suggest functional improvements with PBMT for fibrosis management.
- Mechanisms include anti-inflammatory effects, reduced oxidative stress, and extracellular matrix regulation.

## Abstract

Radiation induced fibrosis (RIF) is a chronic progressive disabling side effect of radiation therapy in cancer survivors with limited therapeutic options. Photobiomodulation therapy (PBMT) is being propagated as a non-invasive therapeutic option but has limited evidence. This scoping review aims to summarize the effects and mechanisms of PBMT in the prevention and treatment of RIF.

A systematic search was conducted across five databases (PubMed, Scopus, EBSCO, ProQuest, LILACS), and three other platforms (Google Scholar, ResearchGate, Academia.edu). Retrieved studies underwent independent title, abstract, full text screening and data extraction. Quality analysis was performed for human studies to assess methodological rigor.

The review identified three studies that specifically focused on RIF. Since induction of RIF is not common for in vitro and in vivo studies, the screening was expanded to include studies targeting fibroblast cells or fibrosis of any origin. The revised strategy led to inclusion of 26 studies (nine in vitro, 13 in vivo, and four clinical studies). Of these, 20 studies focused on the prevention of fibrosis, while six addressed its treatment. Preclinical studies demonstrated the beneficial effects of PBMT at different phases of fibrosis at cellular level. Clinical studies demonstrated functional improvements. Mechanisms include modulation of inflammatory pathways, fibroblast to myofibroblast conversion, collagen production, reduction of oxidative stress, and regulation of extracellular matrix remodeling.

PBMT demonstrates potential as a non-invasive, safe therapeutic option for RIF, supported by extensive preclinical evidence. However, high-quality clinical trials are necessary to validate its clinical efficacy.

PBMT offers a promising intervention for managing RIF, with potential to enhance body image, self-confidence, functional abilities, and overall quality of life for cancer survivors. This review underscores the need for further research to translate these findings into clinical practice.