Validation of the Skin Symptom Assessment (SSA) questionnaire for the evaluation of radiation dermatitis in breast cancer patients.

Purpose: Radiation dermatitis (RD) is a painful side effect of radiation therapy (RT). The objective of this analysis was to investigate the validity and reliability of the Skin Symptom Assessment (SSA) questionnaire in evaluating the severity of patient- and clinician-reported outcomes for RD in breast cancer patients by comparing it to a validated assessment tool, the Radiation-Induced Skin Reaction Assessment Scale (RISRAS) questionnaire.

Methods: This study compared patient and clinician-reported outcomes for RD from previous clinical trials conducted in a Canadian cancer centre. The analysis included 376 and 38 patients in the two trials using Mepitel Film (doi.org/10.1200) and StrataXRT (clinicaltrials.gov identifier: NCT05594498), respectively. Patients in both studies completed the SSA and RISRAS questionnaires at baseline, 2-weeks post-RT, and 3 months after completion of RT. Clinician SSA and RISRAS assessments were collected at baseline and 2-weeks post-RT. These time points were analyzed longitudinally to investigate the SSA's validity in RD symptom assessment.

Results: The majority of patient-reported items on the SSA and RISRAS assessments demonstrated positive significant associations between symptoms of itchiness, between pain/soreness and pain/discomfort, and between blistering or erythema with burning sensation items. All items in the clinician-reported SSA and clinician component of RISRAS showed positive statistical significance between items measuring erythema, pigmentation or edema with dry desquamation, and blistering/peeling with moist desquamation.

Conclusions: The SSA has been validated for assessing patient- and clinician-reported symptoms of RD accurately as outcomes correlate well with the previously validated RISRAS assessment.