桑原 奈津美¹, 川島 博子²

Natsumi KUWABARA¹, Hiroko KAWASHIMA²

¹三菱京都病院診療技術部放射線技術科, ²金沢大学医薬保健研究域保健学系

¹Department of Clinical Technology, Mitsubishi Kyoto Hospital, ²Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University

キーワード : breast ultrasonography, breast conservation therapy, skin thickening, skin edema, interstitial fluid collection

目的：乳房温存療法（breast after breast conservation therapy : BCT）では超音波画像に様々な変化が生じる．しかし，その経過は患者によって異なる．本検討では，BCT後の画像所見の遷延に影響を与える因子について検討した．対象と方法：対象は2010年1月から2014年12月までにBCTを受けた患者101名（103乳房）である．放射線治療終了後18ヵ月で乳房超音波を行い，患側乳房の皮下浮腫/液体貯留および皮膚肥厚の有無について評価を行った．また，画像所見の遷延に影響を与える因子の候補として，手術時年齢，BMI，乳房の大きさ，乳房の構成，術式，切除長径，腫瘍の占拠領域について評価を行った．結果と考察：放射線治療後18ヵ月で皮下浮腫/液体貯留を認めたのは29例（28％），皮膚肥厚を認めたのは60例（58％）であった．皮膚肥厚は，脂肪性の乳房で残りやすく（p＝0.041），切除長径が40 mm以上で残りやすい傾向があった（p＝0.041）．皮下浮腫/液体貯留は，腫瘍の占拠領域が乳房下部領域で残りやすい傾向があった（p＝0.006）．また腫瘍の占拠領域が乳房外側領域であると皮膚肥厚が残りやすい傾向があった（p＝0.027）．結論：BCT後の皮下浮腫/液体貯留と皮膚肥厚の遷延には腫瘍の占拠領域が影響していることが示唆された. 皮膚肥厚は，脂肪性の乳房と切除長径が大きい場合に残りやすい傾向があった．

Purpose: The breast after breast conservation therapy (BCT) presents characteristic ultrasound findings, but the course of the change in findings varies from patient to patient. The purpose of this study was to investigate factors affecting the protraction of image findings after BCT. Subjects and Methods: Between 2010 and 2014, we identified 101 breast cancer patients (103 breasts) after BCT. Based on breast ultrasonography performed 18 months after completion of radiotherapy, we evaluated the presence of interstitial fluid collection and skin edema of the diseased side. Furthermore, we evaluated the relationship between those findings and age, BMI, breast size, breast composition, operation method, the extent of resection, and tumor location. Results and Discussion: Twenty-nine cases (28%) showed interstitial fluid collection and 60 cases (58%) showed skin thickening at 18 months after radiation therapy. Skin thickening tended to remain in fatty breast (p=0.041), and also skin thickening tended to remain when the longer axes of resection were 40 mm or more (p=0.041). Interstitial fluid collection tended to remain when the tumor location was the lower region (p=0.006), and skin thickening tended to remain when the tumor location was the outside region (p=0.027). Conclusion: Our data suggested that tumor location affected the protraction of interstitial fluid collection and skin thickening after BCT. Skin thickening tended to remain in fatty breast and when the extent of resection was large.