The usefulness of sentinel lymph node detection using fluorescent beads for gastric cancer

本研究探讨荧光珠（FB）检测胃癌前哨淋巴结（SN）的可行性。我们假设荧光珠可能反映了淋巴管中癌细胞的流动，因为荧光珠的颗粒直径与癌细胞相似。手术前一天，通过内窥镜在病变周围粘膜下层4个点注射1ml FB。术中进行紫外线照射，提取淋巴结照射检测SN。假设发光淋巴结（LN）为SN。同时，术中从病灶周围的浆膜侧经鼻下层注射染色（ICG）法检测SN。对25例早期胃癌患者进行SN检测。FB方法的SN检出率为76%（19/25）。平均SN数为2.3个。FB联合ICG方法对SN的检出率为92%（23/25）。我们根据原发肿瘤部位研究了荧光珠SN在早期癌症中的分布。上半部分1例，ⅰ室检出SN。中部14例，ⅰ室检出SN(76%)，ⅱ室检出SN（24%）。下半部分5例，分别在1室（88%）和2室（12%）检出SN。我们发现了一例假阴性病例。在此病例中，在SN站区域外检测到转移淋巴结。本例肿瘤大小为75×40mm，因此对于大肿瘤不宜进行SN检测。早期癌症的转移阳性病例只是这个假阴性病例。由于早期胃癌数量较少，我们无法揭示FB方法的准确性。此外，由于脂肪组织的自身荧光，在手术过程中很难检测到隐藏在脂肪组织中的荧光LN。为了将来将FB应用于临床，需要设计一种新的紫外照射仪器在手术中检测SN，同时FB方法应与其他示踪剂相结合。另一点应研究的是微转移，因为它可能有助于患者的预后。因此，我们采用抗细胞角蛋白（AE1/AE3）治疗所有切除的淋巴结，并研究了25例早期胃癌的微转移。在3例病例中，我们检测到微转移。其中1例位于SN站外，采用FB法和染色法联合检测。因此，我们研究微转移的存在是否影响胃癌患者的预后。而微转移阳性与阴性间无显著性差异。我们的结论是，微转移的存在与预后不良无关。由此可见，对于早期胃癌，可采用染色或FB联合SN站淋巴结清扫的方法行SN导航手术。然而，由于我们的病例数量较少，FB方法的有用性无法揭示。少

This study investigated the availability of fluorescent beads (FB) methods for detecting of sentinel lymph node (SN) for patients with gastric carcinoma (GC). We hypothesized that the fluorescent beads might reflect the flow of cancer cells in lymphatic vessels, because a particulate diameter of the fluorescent beads was similar to a cancer cell.On the day before surgery, 1ml of FB was injected by an endoscope to four points of submucosal layer around the lesion. Ultraviolet (UV) irradiation was performed during the operation, and extracted lymph nodes were irradiated to detect SN. Light-emitting lymph nodes (LN) were assumed to be SN. At the same time, SN was detected by dye (ICG) methods injected into the subserasal layear from the serosal side surrounding a lesion at the operation time. SN detection was performed for 25 patients with early GC. The SN detection rate was 76% (19/25) in FB methods. The average number of SN was 2.3. The SN detection rate using FB combined with ICG metho … More ds was 92%(23/25). We investigated the distribution of fluorescent beads SN for an early cancer eases according to a primary tumor site. One case in the upper part, SN was detected in compartment I. Fourteen cases in the middle part, SN were detected in compartment I(76%), and compartment II(24%). Five cases in the lower part, the SN were detected in compartment I(88%), and compartment II(12%). We recognized one false-negative case. In that case, the metastatic lymph node was detected out of the area of SN station. The size of tumor in this case was 75×40mm, therefore the large size tumor should not be indicated for SN detection. A metastasis positive case in early cancer was only this false-negative case. We could not reveal the accuracy of FB method because of small number of early gastric cancer. Moreover, it was difficult to detect a fluorescent LN hidden in the adipose tissue during surgery because of autofluorescence of the adipose tissue. For the purpose of application FB to clinical use in the future, a new UV irradiation instrumental should be devised to detect SN during the operation and the FB methods should be combined with other tracer at the same time. Another point should be investigated is a micrometastasis, because it might contribute to the patients prognosis. Therefore we used anticytokeratin (AE1/AE3) for all resected lymph nodes and investigated micrometastasis in 25 early gastric cancer cases. In three cases, we detected micrometastasis. One case of them was situated out of SN station, which was detected by combined FB and dye method. Therefore, we examined whether the presence of micrometastasis influence to the prognosis for gastric cancer cases. However we couldn't recognize the significant difference between positive and negative of micrometastasis. We concluded that the presence of micrometastasis didn't contribute to the poorer prognosis.From these results, SN navigation surgery could be indicated for early GC by dye or combined FB methods with the lymph nodes dissection of SN station. However, the usefulness of FB method could not be revealed because of our small number of cases. Less