Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University Mainz, Mainz, Germany.
Int J Radiat Oncol Biol Phys. 2012 Feb 1;82(2):842-8. doi: 10.1016/j.ijrobp.2010.08.057. Epub 2011 Jan 13.
To assess response of locally advanced rectal carcinoma to chemoradiation with regard to mucinous status and local tumor invasion found at pretherapeutic magnetic resonance imaging (MRI).
A total of 88 patients were included in this prospective study of patients with advanced mrT3 and mrT4 carcinomas. Carcinomas were categorized by MRI as mucinous (mucin proportion >50% within the tumor volume), and as nonmucinous. Patients received neoadjuvant chemoradiation consisting of 50.4 Gy (1.8 Gy/fraction) and 5-fluorouracil on Days 1 to 5 and Days 29 to 33. Therapy response was assessed by comparing pretherapeutic MRI with histopathology of surgical specimens (minimum distance between outer tumor edge and circumferential resection margin = CRM, T, and N category).
A mucinous carcinoma was found in 21 of 88 patients. Pretherapeutic mrCRM was 0 mm (median) in the mucinous and nonmucinous group. Of the 88 patients, 83 underwent surgery with tumor resection. The ypCRM (mm) at histopathology was significantly lower in mucinous carcinomas than in nonmucinous carcinomas (p ≤ 0.001). Positive resection margins (ypCRM ≤ 1 mm) were found more frequently in mucinous carcinomas than in nonmucinous ones (p ≤ 0.001). Treatment had less effect on local tumor stage in mucinous carcinomas than in nonmucinous carcinomas (for T downsizing, p = 0.012; for N downstaging, p = 0.007). Disease progression was observed only in patients with mucinous carcinomas (n = 5).
Mucinous status at pretherapeutic MRI was associated with a noticeably worse response to chemoradiation and should be assessed by MRI in addition to local tumor staging to estimate response to treatment before it is initiated.
通过术前磁共振成像（MRI）评估黏液状态和局部肿瘤侵袭程度，评估局部晚期直肠癌对放化疗的反应。
本前瞻性研究共纳入 88 例进展期 mrT3 和 mrT4 癌患者。根据 MRI 结果，将肿瘤分为黏液型（肿瘤体积内黏液比例＞50%）和非黏液型。患者接受新辅助放化疗，方案为 50.4 Gy（1.8 Gy/次），氟尿嘧啶 5-FU 5 天，29 天至 33 天，每天一次。通过比较术前 MRI 与手术标本的组织病理学（肿瘤外缘与环周切缘之间的最小距离=CRM、T、N 分期）来评估治疗反应。
88 例患者中，21 例为黏液型癌。黏液型和非黏液型组术前 mrCRM 均为 0mm（中位数）。88 例患者中，83 例行手术切除肿瘤。黏液型癌的 ypCRM（mm）在组织病理学上显著低于非黏液型癌（p≤0.001）。黏液型癌的阳性切缘（ypCRM≤1mm）较非黏液型癌更为常见（p≤0.001）。黏液型癌的局部肿瘤分期治疗效果较非黏液型癌差（T 分期缩小，p=0.012；N 分期降低，p=0.007）。只有黏液型癌患者（n=5）出现疾病进展。
术前 MRI 黏液状态与放化疗反应明显相关，在开始治疗前，应通过 MRI 评估局部肿瘤分期以评估治疗反应，除了局部肿瘤分期外，还应评估黏液状态。
