A systematic review and meta-analysis published in the November 2024 issue of Photodiagnosis and Photodynamic Therapy examined the efficacy of photodynamic therapy (PDT) for treating oral mucositis in cancer patients. The study, conducted by researchers from institutions in Finland, India, Switzerland, Qatar, and Sweden, aimed to evaluate PDT's effectiveness in reducing the severity of chemotherapy-induced oral mucositis and associated symptoms compared to standard care or other interventions.
The review included seven studies published between January 1, 2000, and May 31, 2024, comprising both randomized controlled trials and non-randomized clinical trials. A total of 190 participants (111 males, 79 females) were included across the studies. The researchers performed a comprehensive literature search in multiple databases, including PubMed, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials.
Inclusion criteria for the review encompassed studies involving cancer patients of all ages with chemotherapy-induced oral mucositis who received PDT using lasers or LEDs with any photosensitizing dye. The primary outcome measure was the reduction in lesion severity, with secondary outcomes including pain reduction and healing time. The review also considered whether patients received concurrent radiotherapy and documented radiation techniques, total doses, and fractionation schedules when available.
The meta-analysis, which included four of the seven studies, revealed a statistically significant reduction in oral mucositis severity with PDT. The estimated average standardized mean difference was -0.5138 (95% CI: -0.8799 to -0.1477), indicating a moderate effect size in favor of PDT. The analysis showed low to moderate heterogeneity (I² = 10.78%) among the included studies, suggesting some consistency in treatment effects.
Key findings from the review indicated that PDT, especially when combined with photobiomodulation therapy (PBMT), showed promise in reducing the severity of oral mucositis and associated symptoms in cancer patients. Studies combining PDT with PBMT consistently demonstrated superior therapeutic outcomes compared to PBMT alone, particularly in accelerating healing and reducing pain. The review also highlighted PDT's effectiveness and tolerability in pediatric populations, an important consideration for managing oral complications in children undergoing cancer treatment.
However, the study had several limitations. There was considerable variability in treatment protocols across the included studies, making direct comparisons challenging. The heterogeneity encompassed differences in photosensitizer types, light wavelengths, energy densities, treatment frequencies, and combination protocols. Additionally, most studies had short follow-up periods, typically ranging from immediate post-treatment to only a few weeks, which limited the ability to assess long-term effects and treatment durability.
The review also noted a geographical concentration of studies, with the majority conducted in Brazil, raising concerns about the generalizability of results to other populations. The risk of bias assessment revealed methodological flaws in some studies, particularly in non-randomized trials, with issues such as lack of blinding and inadequate control for confounding factors.
Despite these limitations, the authors concluded that PDT shows promise as an effective treatment for chemotherapy-induced oral mucositis in cancer patients. They emphasized the need for further research to establish standardized protocols and determine optimal treatment parameters. The review suggested that future studies should focus on larger-scale clinical trials with diverse patient populations, longer follow-up periods, and more comprehensive outcome measures.
The potential clinical impact of this review is significant. Oral mucositis is a common and debilitating side effect of cancer treatment that can significantly impact patients' quality of life and potentially lead to treatment interruptions. The findings suggest that PDT, particularly when combined with PBMT, could offer an effective and well-tolerated treatment option for managing this challenging complication. The review's emphasis on PDT's efficacy in pediatric populations is especially noteworthy, as it could provide a valuable tool for managing oral complications in children undergoing cancer treatment.
However, the authors caution that the current evidence base is limited by the heterogeneity of treatment protocols and study designs. They recommend that clinicians carefully consider their specific patient populations and available evidence when selecting treatment parameters. The review also highlights the need for standardization in future research, including consistent photosensitizers, light parameters, treatment schedules, and outcome measures to facilitate more meaningful study comparisons and determine the most effective approach.
In conclusion, this systematic review and meta-analysis provide valuable insights into the potential of PDT for managing chemotherapy-induced oral mucositis. While the results are promising, they also underscore the need for further high-quality research to establish PDT as a standard treatment option in oncology care. As research in this area continues to evolve, medical professionals should stay informed about developments in PDT protocols and consider its potential application in appropriate clinical scenarios.
References
Joseph B, Mauramo M, Vijayakumary BK, Waltimo T, Anil S, Sorsa T. Photodynamic therapy for oral mucositis in cancer patients- a systematic review and meta-analysis. Photodiagnosis Photodyn Ther. 2024;50:104424. doi:10.1016/j.pdpdt.2024.104424
