Takenaka Tadashi, Yamazaki Hideya, Suzuki Gen, Aibe Norihiro, Masui Koji, Shimizu Daisuke, Nishimura Takeshi, Nakashima Akihiro, Ogata Toshiyuki, Matsushita Keiichiro, Yoshida Ken, Yamada Kei
Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
In Vivo. 2018 Nov-Dec;32(6):1499-1504. doi: 10.21873/invivo.11406.
BACKGROUND/AIM: To examine the correlation between dosimetric parameters and acute radiation dermatitis in early breast cancer patients subjected to post-operative radiotherapy.
The data of 84 patients treated with post-operative radiotherapy were analyzed. The total prescribed dose was 50 Gy in 25 fractions over 5 weeks. Radiation dermatitis was assessed according to Common Terminology Criteria for Adverse Events v4.0. We set organ at risk whole body (from neck to abdomen examined by CT images) also as surrogate skin volume (3 mm thickness).
A total of 28 patients showed radiation dermatitis grade equal or higher than 2 at the 50 Gy time point. These 28 patients were compared to 56 matched pair patients with grade 0-1 radiation dermatitis during the same treatment period. The mean of V5-20 and V40 in patient's whole volume and V40-50 in skin volume were significantly higher in patients who presented with acute radiation dermatitis Grades ≥2 than in the other patients who did not. The statistically most significant difference was observed for V40 for skin volume and V5 for patient whole volume. Rate of acute radiation dermatitis grade ≥2 was significantly higher for patients with V5 (whole body) >1,360 cm than those with V5 (whole body) <1,360 cm (47% vs. 27%, p=0.0353), as well as for patients with V40 (skin volume) >45 cm compared with those with V40 (skin volume) <45 cm (50% vs. 18%, p=0.0043).
Dosimetric parameters were useful to predict radiation dermatitis grade ≥2. V5 (whole body) 1,360 cm and V40 (skin volume) 45 cm may be dose volume constrain for radiation dermatitis grade ≥2.
背景/目的：探讨早期乳腺癌术后放疗患者剂量学参数与急性放射性皮炎之间的相关性。
分析84例接受术后放疗患者的数据。总处方剂量为50 Gy，分25次，在5周内完成。根据《不良事件通用术语标准》第4.0版评估放射性皮炎。我们将通过CT图像检查的从颈部到腹部的全身危及器官也设定为替代皮肤体积（厚度为3 mm）。
共有28例患者在50 Gy时间点出现放射性皮炎2级及以上。将这28例患者与同期56例配对的0 - 1级放射性皮炎患者进行比较。急性放射性皮炎≥2级患者的全身V5 - 20和V40均值以及皮肤体积的V40 - 50均值显著高于未出现该情况的其他患者。皮肤体积的V40和全身的V5差异具有统计学意义。全身V5>1360 cm³的患者急性放射性皮炎≥2级的发生率显著高于全身V5<1360 cm³的患者（47%对27%，p = 0.0353），皮肤体积V40>45 cm³的患者与皮肤体积V40<45 cm³的患者相比也是如此（50%对18%，p = 0.0043）。
剂量学参数有助于预测2级及以上放射性皮炎。全身V5 1360 cm³和皮肤体积V40 45 cm³可能是2级及以上放射性皮炎的剂量体积限制。
