Bacterial Decolonization for Prevention of Radiation Dermatitis

Abstract

ImportanceEvidence-based approaches for the prevention of acute radiation dermatitis (ARD) are limited, and additional strategies are necessary to optimize care.ObjectiveTo determine the efficacy of bacterial decolonization (BD) to reduce ARD severity compared with standard of care.Design, Setting, and ParticipantsThis phase 2/3 randomized clinical trial was conducted from June 2019 to August 2021 with investigator blinding at an urban academic cancer center and enrolled patients with breast cancer or head and neck cancer receiving radiation therapy (RT) with curative intent. Analysis was performed on January 7, 2022.InterventionsIntranasal mupirocin ointment twice daily and chlorhexidine body cleanser once daily for 5 days prior to RT and repeated for 5 days every 2 weeks through RT.Main Outcomes and MeasuresThe primary outcome as planned prior to data collection was the development of grade 2 or higher ARD. Based on wide clinical variability of grade 2 ARD, this was refined to grade 2 ARD with moist desquamation (grade 2-MD).ResultsOf 123 patients assessed for eligibility via convenience sampling, 3 were excluded, and 40 refused to participate, with 80 patients in our final volunteer sample. Of 77 patients with cancer (75 patients with breast cancer [97.4%] and 2 patients with head and neck cancer [2.6%]) who completed RT, 39 were randomly assigned BC, and 38 were randomly assigned standard of care; the mean (SD) age of the patients was 59.9 (11.9) years, and 75 (97.4%) were female. Most patients were Black (33.7% [n = 26]) or Hispanic (32.5% [n = 25]). Among patients with breast cancer and patients with head and neck cancer (N = 77), none of the 39 patients treated with BD and 9 of the 38 patients (23.7%) treated with standard of care developed ARD grade 2-MD or higher (P = .001). Similar results were observed among the 75 patients with breast cancer (ie, none treated with BD and 8 [21.6%] receiving standard of care developed ARD grade ≥2-MD; P = .002). The mean (SD) ARD grade was significantly lower for patients treated with BD (1.2 [0.7]) compared with patients receiving standard of care (1.6 [0.8]) (P = .02). Of the 39 patients randomly assigned to BD, 27 (69.2%) reported regimen adherence, and only 1 patient (2.5%) experienced an adverse event related to BD (ie, itch).Conclusions and RelevanceThe results of this randomized clinical trial suggest that BD is effective for ARD prophylaxis, specifically for patients with breast cancer.Trial RegistrationClinicalTrials.gov Identifier: NCT03883828

Bacterial Decolonization for Prevention of Radiation Dermatitis—Fragility Index Analysis

“…The Fragility Index (FI) is an epidemiological tool that can quantitatively assess this counterfactual and determine the minimum needed change in number of events for the results to become nonsignificant . We calculated the FI for the trial end points of rates of grade 2 or higher moist desquamation and S aureus colonization between the 2 groups.…”

“…The findings from Kost et al of significantly reduced rates of moist desquamation and S aureus colonization are notable and robust. Future investigations on this topic could be encouraged to be validated in other and larger settings.…”

“…To the Editor The randomized clinical trial by Kost et al reported recently in JAMA Oncology compared bacterial decolonization to standard of care for the prevention of radiation dermatitis. They found that patients who received bacterial decolonization for the prophylaxis of radiation dermatitis had significantly lower rates of grade 2 or higher moist desquamation and Staphylococcus aureus colonization.…”

“…Recognizing that this study had a modest sample size of 77 patients randomized across 2 groups, there may exist a counterfactual situation, ceteris paribus, where a small change in the number of patients reporting these events may lead to a change from a significant to a nonsignificant result. The Fragility Index (FI) is an epidemiological tool that can quantitatively assess this counterfactual and determine the minimum needed change in number of events for the results to become nonsignificant .…”

Association of Skin Microbiome Dynamics With Radiodermatitis in Patients With Breast Cancer

“…Recently published studies have suggested an association between nasal microbiome colonization and severity of radiodermatitis, as well as radiodermatitis recovery outcomes based on skin microbiome . Furthermore, a randomized clinical trial showed that skin decolonization may be effective for acute radiodermatitis prophylaxis . However, to our knowledge, research has yet to unravel the pathomechanism and association of the skin microbiome before and during radiotherapy with radiodermatitis severity.…”