Medical Physics and Informatics Laboratory of Electronics Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan, ROC.
Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC.
PLoS One. 2018 Jul 16;13(7):e0200192. doi: 10.1371/journal.pone.0200192. eCollection 2018.
To evaluate the relationships among patient characteristics, irradiation treatment planning parameters, and treatment toxicity of acute radiation dermatitis (RD) after breast hybrid intensity modulation radiation therapy (IMRT). The study cohort consisted of 95 breast cancer patients treated with hybrid IMRT. RD grade ≥2 (2+) toxicity was defined as clinically significant. Patient characteristics and the irradiation treatment planning parameters were used as the initial candidate factors. Prognostic factors were identified using the least absolute shrinkage and selection operator (LASSO)-based normal tissue complication probability (NTCP) model. A univariate cut-off dose NTCP model was developed to find the dose-volume limitation. Fifty-two (54.7%) of ninety-five patients experienced acute RD grade 2+ toxicity. The volume of skin receiving a dose >35 Gy (V35) was the most significant dosimetric predictor associated with RD grade 2+ toxicity. The NTCP model parameters for V35Gy were TV50 = 85.7 mL and γ50 = 0.77, where TV50 was defined as the volume corresponding to a 50% incidence of complications, and γ50 was the normalized slope of the volume-response curve. Additional potential predictive patient characteristics were energy and surgery, but the results were not statistically significant. To ensure a better quality of life and compliance for breast hybrid IMRT patients, the skin volume receiving a dose >35 Gy should be limited to <85.7 mL to keep the incidence of RD grade 2+ toxicities below 50%. To avoid RD toxicity, the volume of skin receiving a dose >35 Gy should follow sparing tolerance and the inherent patient characteristics should be considered.
评估患者特征、照射治疗计划参数与乳腺癌混合调强放疗后急性放射性皮炎（RD）治疗毒性之间的关系。该研究队列包括 95 例接受混合调强放疗的乳腺癌患者。将 RD 分级≥2（2+）毒性定义为具有临床意义的毒性。将患者特征和照射治疗计划参数作为初始候选因素。使用最小绝对值收缩和选择算子（LASSO）基于正常组织并发症概率（NTCP）模型来识别预后因素。建立单变量截止剂量 NTCP 模型以找到剂量-体积限制。95 例患者中有 52 例（54.7%）发生了急性 RD 分级 2+毒性。接受剂量>35Gy（V35）的皮肤体积是与 RD 分级 2+毒性最显著的剂量学预测因素。V35Gy 的 NTCP 模型参数为 TV50=85.7mL 和γ50=0.77，其中 TV50 定义为并发症发生率为 50%的体积，γ50 为体积-反应曲线的归一化斜率。还有其他潜在的预测性患者特征是能量和手术，但结果无统计学意义。为确保乳腺癌混合调强放疗患者的生活质量和依从性更好，应将接受剂量>35Gy 的皮肤体积限制在<85.7mL，以使 RD 分级 2+毒性的发生率低于 50%。为避免 RD 毒性，应遵循皮肤接受剂量>35Gy 的耐受量，并考虑固有患者特征。
