2857 - Skin-Related Quality of Life during Radiotherapy across Diverse Fitzpatrick Skin Types and its Association with Radiation Dermatitis
Presenter(s)
A. F. M. Salem1, K. N. Nordlund1, Y. Yi2, R. Lin3, C. D. Fuller4, S. F. Shaitelman4, A. Lee1, C. R. Goodman5, B. A. Guadagnolo1, A. J. Bishop1, A. Farooqi1, D. Mitra1, and A. K. Yoder1; 1Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 2The University of Texas MD Anderson Cancer Center, Houston, TX, 3Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, 4Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 5University of Texas MD Anderson Cancer Center, Houston, TX
Purpose/Objective(s): Cutaneous toxicity is the most common radiotherapy (RT) associated side effect. The effect of baseline skin phototype/pigmentation on RT-induced changes in skin-related quality of life (SR-QOL) is poorly characterized. We sought to comprehensively assess SR-QOL using the Skindex-16 (SD-16) survey, comparing differences between low melanin and high melanin Fitzpatrick (FZ) skin phototypes, and evaluating its association with radiation dermatitis (RD) grade.
Materials/Methods: We prospectively enrolled 98 pts between 2022–2025 on a study to evaluate the effect of conventionally fractionated RT on skin toxicity in head and neck cancer, breast cancer, and sarcoma. Patients were eligible if skin D50cc>48 Gy. SD-16 was administered weekly through 4 weeks post-RT, with higher scores indicating worse SR-QOL. Matched timepoint photos were graded by 3 blinded radiation oncologists using the RTOG Modified Radiation Dermatitis Scale. For analysis, patients were grouped as low baseline melanin (FZ 1-3) vs. high baseline melanin (FZ 4-6), as measured by handheld spectrophotometer. Comparisons were performed by Wilcoxon rank-sum test, Chi-Square test, or Fisher’s exact test. Longitudinal changes were analyzed using linear mixed-effects models. Associations between SD-16 score and RD were assessed by Spearman's rank correlation coefficients.
Results: 76% pts (n=74) were FZ 1-3 vs. 24% (n=24) FZ 4-6. Baseline SD-16 was 9.8 ± 1.9 for FZ 1-3 vs. 6 ± 3 for FZ 4-6 (p=0.056). In patients from both cohorts SD-16 increased during RT starting consistently at week 4, with maximum increase in the last 2 weeks, peak during the week post-RT completion, and improvement by 4 weeks post-RT (p<0.001). The change from baseline was significantly greater for FZ 4-6 patients (32.9 ± 6.7 vs 25.5 ± 3, p=0.038). The trajectory was similar between FZ 1-3 and FZ 4-6 pts (p=0.27), although FZ 4-6 patients experienced greater transient worsening at week 5 (p=0.045). FZ 4-6 pts were more likely to develop peak RD =2.5 (79% vs. 46%, p=0.005). For the entire cohort, the weekly physician-assessed RD grade was correlated with the weekly SD-16 score starting at week 3 and persisting through follow up (?=0.25-0.43, all p<0.05). The correlation between RD and SD-16 was highest for FZ 4-6 pts (?=0.54, p=0.03), suggesting a particularly robust relationship between RD and SR-QOL for patients with high baseline melanin.
Conclusion: SR-QOL worsened during RT and improved during follow up, with FZ 4-6 pts having greater peak deterioration. RD correlated with SR-QOL, highlighting the value of incorporating patient-reported outcomes to aid in assessing RT-related toxicity across diverse skin types.