导管原位癌 (DCIS) 约占新诊断乳腺癌的 30%。然而，我们对正常乳腺组织如何演变为导管原位癌和浸润性癌症的了解仍然不足。此外，关于疾病进展机制的组织病理学、遗传学和放射学结论往往是相互矛盾的，并且对治疗计划有影响。此外，自从采用有组织的乳腺癌筛查计划以来，DCIS 诊断的增加引起了人们对过度诊断和随后过度治疗的担忧。主动监测是导管原位癌 (DCIS) 的一种非手术治疗策略，可避免手术，有利于密切影像随访以逐步降低治疗规模，并提供更多治疗选择。然而，主动监测的两个主要挑战是识别隐匿性浸润性癌症和有浸润性癌症进展风险的患者。随后，正在进行四项前瞻性主动监测试验，以确定主动监测的可行性并完善患者资格标准和随访间隔。放射科医生在确定主动监测和审查疾病进展监测图像的资格方面发挥着重要作用。未来几年发布的试验结果将支持多学科 DCIS 护理的新时代。版权所有 © 2024 韩国放射学会。

Ductal carcinoma in situ (DCIS) accounts for approximately 30% of new breast cancer diagnoses. However, our understanding of how normal breast tissue evolves into DCIS and invasive cancers remains insufficient. Further, conclusions regarding the mechanisms of disease progression in terms of histopathology, genetics, and radiology are often conflicting and have implications for treatment planning. Moreover, the increase in DCIS diagnoses since the adoption of organized breast cancer screening programs has raised concerns about overdiagnosis and subsequent overtreatment. Active monitoring, a nonsurgical management strategy for DCIS, avoids surgery in favor of close imaging follow-up to de-escalate therapy and provides more treatment options. However, the two major challenges in active monitoring are identifying occult invasive cancer and patients at risk of invasive cancer progression. Subsequently, four prospective active monitoring trials are ongoing to determine the feasibility of active monitoring and refine the patient eligibility criteria and follow-up intervals. Radiologists play a major role in determining eligibility for active monitoring and reviewing surveillance images for disease progression. Trial results published over the next few years would support a new era of multidisciplinary DCIS care.Copyright © 2024 The Korean Society of Radiology.