Williamson P R, Hellinger M D, Larach S W, Ferrara A
Orlando Regional Medical Center, Orlando, Florida, USA.
Dis Colon Rectum. 1996 Jan;39(1):45-9. doi: 10.1007/BF02048268.
This study was undertaken to assess the accuracy and ability of endorectal ultrasound (ERUS) to predict changes in rectal tumor stage after a preoperative chemoradiation protocol.
Since December 1990, all rectal malignancies at our institution have been preoperatively staged with ERUS. ERUS has been an essential tool in preoperative staging of rectal cancer patients, possessing an overall accuracy of 84 percent for T stage and 81 percent for lymph node status in our hands (Williamson PR, unpublished data). Beginning in July 1992, all patients staged with T3 or T4 lesions on initial ERUS have been entered into a protocol consisting of preoperative chemoradiation therapy (CRT). This protocol consists of patients receiving 4,500 to 5,040 rads for five to eight weeks and concomitantly receiving sensitizing doses of 5-fluorouracil and/or leucovorin. All patients were scheduled for sphincter-saving or abdomino-perineal resections six to eight weeks following completion of CRT. A repeat ERUS was performed on each patient one week before surgery.
The study group consisted of 15 patients who completed CRT, including 12 males and 3 females. Evidence of tumor shrinkage via ERUS measurement was seen in all patients. Average tumor shrinkage as assessed by ERUS was 16 percent by width and 32 percent by depth of invasion. Sonographic level of invasion and nodal status were each downstaged in 38 percent of patients. Pathologic evaluation comparison revealed that the level of invasion was downstaged in 47 percent and nodal status in 88 percent compared with initial ERUS staging. Of those patients downstaged, 4 of 11 (36 percent) revealed no tumor in the pathology specimen.
We conclude from our early experience that although ERUS offers a method for assessing degree of shrinkage and downstaging of T3 and T4 lesions after CRT, presently it does not closely predict the pathologic results. Results are strongly related to the experience of the ultrasonographer. The ability to distinguish tumor from radiation-induced changes to perirectal tissues is under continued investigation, and a new method of interpreting the data obtained by ERUS after CRT will need to be established.
本研究旨在评估直肠内超声（ERUS）预测术前放化疗方案后直肠肿瘤分期变化的准确性和能力。
自1990年12月起，我院所有直肠恶性肿瘤患者均接受术前ERUS分期检查。在我们手中，ERUS一直是直肠癌患者术前分期的重要工具，T分期的总体准确率为84%，淋巴结状态的总体准确率为81%（Williamson PR，未发表数据）。从1992年7月开始，所有初次ERUS检查显示为T3或T4病变的患者都进入了一个包括术前放化疗（CRT）的方案。该方案包括患者在五至八周内接受4500至5040拉德的放疗，并同时接受敏感剂量的5-氟尿嘧啶和/或亚叶酸。所有患者在完成CRT后六至八周安排进行保肛或腹会阴联合切除术。在手术前一周对每位患者进行重复ERUS检查。
研究组由15名完成CRT的患者组成，其中男性12名，女性3名。所有患者通过ERUS测量均可见肿瘤缩小的证据。通过ERUS评估，肿瘤平均宽度缩小16%，浸润深度缩小32%。38%的患者超声检查的浸润水平和淋巴结状态均降期。病理评估比较显示，与初始ERUS分期相比，浸润水平降期的患者占47%，淋巴结状态降期的患者占88%。在那些降期的患者中，11例中有4例（36%）病理标本中未发现肿瘤。
从我们的早期经验中我们得出结论，尽管ERUS提供了一种评估CRT后T3和T4病变缩小程度和降期的方法，但目前它并不能准确预测病理结果。结果与超声检查人员的经验密切相关。区分肿瘤与直肠周围组织放射性改变的能力仍在持续研究中，需要建立一种新的方法来解释CRT后通过ERUS获得的数据。
