Radiation dermatitis assessment tools used in breast cancer: A systematic review of measurement properties

Purpose This review aimed to assess the quality and efficacy of tools currently used in breast cancer patients to score radiation dermatitis (RD), a common debilitating side effect of radiotherapy (RT). Methods A search was conducted through Ovid Medline, Embase, and Cochrane Central Register of Controlled Trials databases on 14 February 2020. English articles that evaluated an instrument's use in assessing RD among breast cancer patients receiving external beam RT were included. Studies that reported on the reliability, validity, or concordance of items between assessment tools were included in accordance with the Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) criteria. Results Twelve studies were included in this review, with a total of 13 skin toxicity assessment tools discussed. Tools that assessed clinician-reported outcomes (CROs) mostly reported moderate correlation with biophysical parameter (BP) measurements and low correlation with patient-reported outcomes (PROs). Traditionally used CRO scoring tools demonstrated moderate inter-rater reliability between clinicians, likely due to the subjective nature of items on the grading scales. Most commonly used tools were found to be either insufficient or indeterminate in their measurement properties. Conclusions Current standardized tools that measure CROs are subject to clinician interpretation and fail to represent the patient experience. Tools designed to assess PROs are promising in their assessments of the impact of RT on patient quality of life; however, most PRO tools are generic to all skin conditions and require further validation for use in breast cancer. Among tools that measure CROs, PROs, and BPs, there is insufficient evidence on their measurement properties to establish a "gold standard" for the assessment of RD in breast cancer patients.