Investigating bacterial decolonization for the prevention of radiation dermatitis: A randomized controlled trial and quality of life assessment.

TPS12137 Background: Radiation dermatitis (RD) can be therapy-limiting and detrimental to quality of life for cancer patients receiving radiation therapy (RT). Bacteria play an important role in many inflammatory dermatoses. In an observational clinical study, our group discovered that nasal colonization with bacteria, specifically with Staphylococcus aureus (SA), prior to RT was an independent predictor of higher-grade RD (grade ≥2). Higher-grade RD patients were also found to have more SA on the irradiated skin after treatment. If successful, bacterial decolonization could be a safe and cost-effective method to prevent RD. Methods: This is a randomized controlled trial assessing the efficacy of universal bacterial decolonization in preventing RD. Subject inclusion criteria include patients who are aged ≥ 18 years with a diagnosis of a solid tumor of the breast or head and neck with plans for fractionated RT (≥ 15 fractions) with curative intent. Based on previous studies and power analyses, we plan to recruit a total of 80 patients. Patients in the control arm will be treated according to standard of care, including daily application of emollients and gentle bathing. In addition to standard of care, patients in the intervention arm will receive a decolonization regimen consisting of intranasal mupirocin ointment used twice daily and chlorhexidine wash used daily for 5 days prior to the initiation of RT and repeated for 5 days every other week throughout RT. Study evaluations for both groups will include bacterial cultures obtained via superficial swab from the nares, irradiated skin, and contralateral non-radiated skin performed at the beginning, middle, and end of RT. Additionally, standardized photographs of the skin at the radiated site will be performed prior to and at the completion of RT, which will be graded by a dermatologist blinded to study arm. Lastly, at identical timepoints, each patient will complete the SKINDEX-16 questionnaire, a validated quality of life (QoL) assessment. The primary endpoint is development of grade ≥ 2 RD, as compared to low-grade RD (grade 0-1), during RT. The secondary endpoint includes the impact of bacterial decolonization on QoL. Pearson’s chi square or Fisher’s exact tests will be used to compare the incidence rates of higher-grade RD between the interventional arm and control arm to assess if the intervention is associated with a lower incidence rate of higher-grade RD. Paired t-tests will be used to compare the QoL score change from baseline to after RT between the two arms. Linear regression models will be used in both analyses to adjust for covariates. Clinical trial information: NCT03883828.