Purpose: The aim of this study was to assess radiation dermatitis, especially exploring the influence of neoadjuvant systemic therapy (NST).
Materials and methods: We examined maximum toxicity using the Common Toxicity Criteria version 3 score (CTC v3) following radiotherapy between 40 patients treated with NST and 59 patients without NST. In addition, objective skin color (L*, a*, b* values) and moisture analyses were applied in 13 NST and 25 control patients, and the ratio of the values for the irradiated side to the nonirradiated side was calculated.
Results: For the CTC v3 assessment, 27 grade 1 (68%) and 13 grade 2 (32%) reactions occurred in the NST group and 44 grade 1 (75%) and 15 grade 2 (25%) reactions in the control group. All ratios except the b* ratio showed significant alterations when radiotherapy was added. The ratio of the a* value peaked at the completion of radiotherapy, whereas the L* ratio bottomed out 1 month later. Furthermore, moisture change remained even 1 year after treatment. Boost irradiation doses caused enhanced alterations in the L* and a* ratios. Furthermore, the L* and a* ratios had good agreement with the CTC v3 assessment. NST did not enhance alterations.
Conclusion: Objective analysis is useful for detailed assessment of radiation dermatitis. NST did not worsen skin reactions.