Vogel S B, Drane W E, Ros P R, Kerns S R, Bland K I
Department of Surgery, University of Florida College of Medicine, Gainesville.
Ann Surg. 1994 May;219(5):508-14; discussion 514-6. doi: 10.1097/00000658-199405000-00009.
To evaluate the efficacy of two distinct imaging techniques to predict, before operation, unresectability compared with standard computed tomographic scan (CT).
Accurate preoperative identification of the number, size, and location of hepatic lesions is crucial in planning hepatic resection for colorectal hepatic metastases. Although infusion-enhanced CT is the standard, its limitations are the imaging of relatively isodense and/or small (< 1 cm) lesions. The increased sensitivity of CT arterial portography (CTAP) may be offset by false-positive results caused by benign lesions and flow artifacts.
Fifty-eight selected patients considered to be eligible for resection by standard CT had laparotomy. Before operation and in addition to CT, all patients had CT arterial portography and hepatic artery perfusion scintigraphy (HAPS) using radiolabeled macroaggregated albumin. Early studies showed an increased sensitivity for detecting small lesions using the invasive CTAP. Similarly, the HAPS study has detected malignant lesions not observed by standard CT.
Of 58 patients having laparotomy, 40 were resectable by either lobectomy (22) or trisegmentectomy (1) and the rest by single or multiple wedge resections. Eighteen patients could not be resected because of combined intra- and extrahepatic disease or the number and location of metastases. Standard CT detected 64% of all lesions (12% of lesions less than 1 cm). Unresectability was accurately predicted by CTAP and HAPS in 16 (88%) and 15 (83%), respectively, of the 18 patients considered ineligible for resection at laparotomy. Of the 40 patients who had resection for possible cure, CTAP and HAPS falsely predicted unresectability in 6 of 40 patients (15%) and in 10 of 40 patients (25%), respectively. The positive predictive value for unresectability of CTAP and HAPS was 73% and 60%, respectively. False-positive lesions after CTAP included hemangiomas, cysts, granulomas, and flow artifacts. False-positive HAPS lesions included patients in whom no tumor was found at surgery but with some identified by intraoperative ultrasound, blind biopsy, and blind resection.
False-positive results by HAPS and CTAP may limit the ability of these tests to accurately predict unresectability before operation and may deny patients the chance for surgical resection. The HAPS study does, however, detect small lesions not seen by CT or CTAP. Standard CT, although less sensitive, followed by surgery and intraoperative ultrasound, does not necessarily preclude patients who could be resected.
与标准计算机断层扫描（CT）相比，评估两种不同成像技术在术前预测不可切除性的疗效。
准确术前识别肝转移瘤的数量、大小和位置对于规划结直肠癌肝转移的肝切除术至关重要。尽管增强CT是标准方法，但其局限性在于对相对等密度和/或小（<1 cm）病变的成像。CT动脉门静脉造影（CTAP）敏感性的提高可能会被良性病变和血流伪影导致的假阳性结果所抵消。
58例经标准CT评估认为适合手术切除的患者接受了剖腹手术。术前，除了CT检查外，所有患者均接受了CT动脉门静脉造影以及使用放射性标记的大颗粒白蛋白进行的肝动脉灌注闪烁扫描（HAPS）。早期研究表明，使用侵入性CTAP检测小病变的敏感性有所提高。同样，HAPS研究也检测到了标准CT未发现的恶性病变。
58例行剖腹手术的患者中，40例可通过肝叶切除术（22例）或三段切除术（1例）切除，其余患者通过单例或多例楔形切除术切除。18例患者因肝内和肝外合并疾病或转移瘤的数量和位置而无法切除。标准CT检测到所有病变的64%（<1 cm病变的12%）。在18例剖腹手术中被认为不适合切除的患者中，CTAP和HAPS分别准确预测了16例（88%）和15例（83%）的不可切除性。在40例可能治愈性切除的患者中，CTAP和HAPS分别在40例患者中的6例（15%）和10例患者中的10例（25%）中错误预测了不可切除性。CTAP和HAPS对不可切除性的阳性预测值分别为73%和60%。CTAP后的假阳性病变包括血管瘤、囊肿、肉芽肿和血流伪影。HAPS假阳性病变包括手术中未发现肿瘤但术中超声、盲目活检和盲目切除发现一些肿瘤的患者。
HAPS和CTAP的假阳性结果可能会限制这些检查在术前准确预测不可切除性的能力，并可能使患者失去手术切除的机会。然而，HAPS研究确实检测到了CT或CTAP未发现的小病变。标准CT虽然敏感性较低，但随后进行手术和术中超声检查，不一定会排除那些可以切除的患者。
