Predictors of radiation-induced skin toxicity in nasopharyngeal cancer patients treated by intensity-modulated radiation therapy: a prospective study

Purposes Exposure of skin to high doses of radiation may lead to the development of erythematous skin changes. The aims of this study were to measure skin doses and to identify potential factors that may contribute to skin reactions in nasopharyngeal cancer patients undergoing intensity-modulated radiation therapy (IMRT). Material and methods This study was a prospective study with 21 nasopharyngeal cancer patients treated by IMRT. Personal data were collected and in vivo skin dose measurements were performed using Thermoluminescent dosimeters. All patients were monitored clinically and skin reactions were classified according to the Radiation Therapy Oncology Group criteria. Univariate and multivariate logistic regression was conducted using Statistical Package for Social Sciences Software to identify skin toxicity risk factors. Results Grade 1 toxicity was observed in eight patients, Grade 2 in 11 patients and Grade 3 in two patients towards the end of treatment. It was found that accumulative skin doses >7 Gy ( p <0·05) was a risk factor for skin toxicity. However, previous or concomitant chemotherapy with radiotherapy and stage of cancer were not significant factors for the severity of skin reactions. Conclusion The neck skin should be identified as a sensitive structure for dose optimisation. Skin dose measurement and skin-sparing techniques are highly recommended for head and neck patients treated with IMRT.