Natural and miscellaneous agents for the prevention of acute radiation dermatitis: a systematic review and meta-analysis

Purpose: This systematic review and meta-analysis aimed to evaluate the available literature describing the efficacy of natural and miscellaneous agents in preventing acute radiation dermatitis (RD) in cancer patients.

Methods: OVID MedLine, Embase, and Cochrane literature databases were searched from 1946 to January 2023 for randomized controlled trials studying the use of natural and miscellaneous agents to prevent RD. RevMan 5.4 was used for the meta-analysis to calculate the pooled effect sizes and 95% confidence intervals (CI) using the random effects analysis.

Results: For the systematic review and meta-analysis, 19 and 16 studies were included, respectively. Of the five studied natural products (aloe vera, oral enzymes, olive oil, calendula, and curcumin), only oral enzymes and olive oil significantly reduced the incidence of Radiation Therapy Oncology Group grade 2⁺ (RR: 0.42, 95%CI 0.30-0.58, p < 0.00001, RR: 0.66, 95% CI 0.51-0.85, p = 0.001, resp.). The oral enzymes also reduced the grade 3⁺ RD incidence (RR: 0.18, 95%CI 0.06-0.55, p = 0.003). The other agents demonstrated no significant effect.

Conclusion: This review and meta-analysis on natural and miscellaneous agents in preventing RD in cancer patients demonstrated that oral enzymes and olive oil prevented RD severity. However, evidence supporting natural agents to prevent RD is inconsistent, mainly because of low studies numbers, low-quality study designs, and small sample sizes. Therefore, concrete conclusions cannot be made. Research on (new) natural or miscellaneous agents should focus on a randomized controlled double-blinded study design with a large patient population, a higher consistency in research methods, and clinician- and patient-reported outcomes.