Aloe vera for prevention of radiation-induced dermatitis: A systematic review and cumulative analysis of randomized controlled trials

Abstract

Background: Aloe vera were frequently reported to reduce the risk of radiation-induced dermatitis (RID), but the quantitative results from all the relevant studies were not presently available. This study sought to conduct a cumulative analysis to better clarify the preventive effects of aloe vera in RID. Methods: MEDLINE (PubMed), Cochrane, EMBASE, PsychINFO, Web of Science, China National Knowledge Infrastructure (CNKI), and Wan Fang Database were utilized for identifying the eligible randomized controlled trials (RCTs) without language restrictions, up to March 2022. The pooled incidence of RID was conducted by the Relative risk (RR) with its 95% confidence interval (CI) through the STATA software under a random-effects model. This systematic review and cumulative analysis were registered on PROSPERO (ID: CRD42022335188). Results: Fourteen RCTs met our predefined inclusion criteria, enrolling 1,572 participants (mean age: 46.5-56 years). The cumulative results revealed that patients pretreated with aloe vera were associated with a significantly lower risk of RID compared to those without aloe vera usage (RR = 0.76, 95% CI: 0.67-0.88, p < 0.001; heterogeneity: I ² = 79.8%, p < 0.001). In the subgroup analysis, the pooled incidence of Grade 2-4, Grade 2, and Grade 3 RID was also dramatically lower in the group of aloe vera as compared to the placebo group [RR = 0.44 (0.27, 0.74), 0.58 (0.36, 0.94), and 0.27 (0.12, 0.59) in Grade 2-4, Grade 2, and Grade 3, respectively]. However, in regard to Grade 4 RID, the combined RR indicated that the incidence of RID was comparable between aloe vera and the control group (RR = 0.13, 95% CI: 0.02-1.01, p = 0.051; heterogeneity: I ² = 0.0%, p = 0.741). The sensitivity analyses showed that there was no substantial change in the new pooled RR after eliminating anyone of the included study. Conclusion: The current cumulative analysis revealed that patients pretreated with aloe vera were less likely to suffer from RID than the controls without using aloe vera. Based on this finding, the prophylactic application of aloe vera might significantly reduce the incidence of RID, especially in Grade 2 and Grade 3 RID. Further large-sample multicenter RCTs are still warranted to confirm these findings and for better clinical application.

Keywords: aloe vera; cumulative analysis; prevention; radiation-induced dermatitis; systematic review.

FIGURE 1

Flow chart of study selection. 201 studies were firstly identified and fourteen eligible studies were finally included after screening.

FIGURE 2

Risk of bias among the fourteen included studies (A,B). The results turned out that most of the included studies (13/14, 93%) were with high risk of bias.

FIGURE 3

Forest plots of the cumulative analysis of the fourteen included studies on the association between pretreatment with aloe vera and the risk of radiation-induced dermatitis the incidence rate of RID in the study group and the control group: 56% (440/792) vs. 73% (572/780).

FIGURE 4

Forest plots of the cumulative analysis of the protective effects developed by aloe vera in Grade 2–4 (A), Grade 2 (B), Grade 3 (C), and Grade 4 (D)radiation-induced dermatitis (study group: n = 401; control group: n = 398).

FIGURE 5

Sensitivity analysis after each study was excluded by turns with the STATA software.

FIGURE 6

Begg’s rank correlation test (A) and Egger’s regression asymmetry test (B).