Churchill Hospital, Headington, Oxford, UK.
Clin Radiol. 2012 Jun;67(6):546-52. doi: 10.1016/j.crad.2011.11.004. Epub 2012 Jan 2.
To describe the post-chemoradiotherapy magnetic resonance imaging (MRI) features of locally advanced rectal carcinoma (LARC) in which there has been a complete histopathological response to neoadjuvant chemoradiotherapy (CRT).
This retrospective cohort study was performed between January 2005 and November 2009 at a regional cancer centre. Consecutive patients with LARC and a histopathological complete response to long-course CRT were identified. Pre- and post-treatment MRI images were reviewed using a proforma for predefined features and response criteria. ymrT0 was defined as the absence of residual abnormality on MRI.
Twenty patients were included in the study. Seven (35%) ypT0 tumours were ymrT0. All 13 ypT0 tumours not achieving ymrT0 appearances had a good radiological response, with at least 65% tumour reduction. The appearances were heterogeneous: in 11/13 patients the tumour was replaced by a region of at least 50% low signal on MRI, with 8/13 having ≥80% low signal, and 3/13 with 100% low signal.
MRI may be useful in identifying a complete histopathological response. However, the MRI appearances of ypT0 tumours are heterogeneous and conventional MRI complete response criteria will not detect the majority of patients with a complete histopathological response.
描述新辅助放化疗后完全病理缓解的局部进展期直肠癌（LARC）的磁共振成像（MRI）特征。
这是一项 2005 年 1 月至 2009 年 11 月在区域性癌症中心进行的回顾性队列研究。连续纳入 LARC 患者，这些患者对长程放化疗有完全的组织病理学缓解。使用预定义的特征和反应标准的表格回顾治疗前后的 MRI 图像。ymrT0 定义为 MRI 上无残留异常。
研究共纳入 20 例患者。7 例（35%）ypT0 肿瘤为 ymrT0。所有未达到 ymrT0 表现的 13 例 ypT0 肿瘤均有良好的放射学反应，肿瘤至少减少了 65%。表现为异质性：13 例患者中有 11 例肿瘤在 MRI 上被至少 50%的低信号取代，8 例患者的低信号至少为 80%，3 例患者的低信号为 100%。
MRI 可能有助于识别完全的组织病理学缓解。然而，ypT0 肿瘤的 MRI 表现具有异质性，传统的 MRI 完全缓解标准无法检测出大多数具有完全组织病理学缓解的患者。
