Haruto Nishimura

Preoperative diagnosis of lymph node metastases in gastric cancer by magnetic resonance imaging with ferumoxtran-10.

BackgroundKnowledge regarding the presence and location of lymph node metastasis in gastric cancer is essential in deciding on the operative approach. Lymph node metastases have been diagnosed with imaging tests such as computed tomography (CT) and ultrasonography (US); however, the accuracy of such diagnoses, based on size and shape criteria, has not been adequate. Ferumoxtran-10 (Combidex; Advanced Magnetics) is a lymphotropic contrast agent for magnetic resonance imaging (MRI) whose efficacy for the detection of metastatic lymph nodes in various cancers has been reported by several investigators; however, its efficacy for this purpose has not been reported for gastric cancer. We investigated the efficacy of ferumoxtran-10-enhanced MRI for the diagnosis of metastases to lymph nodes in gastric cancer.MethodsSeventeen consecutive patients who were diagnosed with a nonearly stage of gastric cancer were enrolled in the study. All the patients were examined by MRI (Signa Horizon 1.5 T; GE Medical; T2*-weighted images) before and 24 h after the intravenous administration of ultrasmall particles of superparamagnetic iron oxide — ferumoxtran-10 (2.6 mg Fe/kg of body weight) — and the presence or absence of metastasis was determined from the enhancement patterns. The imaging results were compared with the corresponding histopathological findings following surgery.ResultsOf 781 lymph nodes dissected during surgery, the imaging results of 194 nodes could be correlated with their histopathological findings. Fifty-nine lymph nodes from 11 patients had histopathological metastases. In nonaffected normal lymph nodes, we observed dark signal intensity on MRI caused by the diffuse uptake of the contrast medium by macrophages resident in the lymph nodes, which phagocytose the iron oxide particles of ferumoxtran-10. The number of phagocytic macrophages was decreased in metastatic lymph nodes, and they showed various patterns of decreased uptake of ferumoxtran-10. Three enhancement patterns were observed in lymph nodes: (A) lymph nodes with overall dark signal intensity due to the diffuse uptake of ferumoxtran-10; (B) lymph nodes with partial high signal intensity due to partial uptake; and (C) no blackening of lymph nodes due to no uptake of ferumoxtran-10. Patterns (B) and (C) were defined as metastatic. The sensitivity, specificity, positive predictive value, negative predictive value, and overall predictive accuracy of postcontrast MRI were 100% (59/59), 92.6% (125/135), 85.5% (59/69), 100% (125/125), and 94.8% (184/194), respectively. These parameters for predictive accuracy were much superior to these parameters previously evaluated by CT or US. Nodes in the retroperitoneal and paraaortic regions were more readily identified and diagnosed on the MR images than those in the perigastric region.ConclusionThe present study confirmed that ferumoxtran-10-enhanced MRI is useful in the diagnosis of metastatic lymph nodes and that the use of this modality will be helpful in treatment decision-making for gastric cancer patients.

Evaluation of lymph node metastases in gastric cancer using magnetic resonance imaging with ultrasmall superparamagnetic iron oxide (USPIO): diagnostic performance in post-contrast images using new diagnostic criteria

BackgroundWe assessed the value of magnetic resonance imaging (MRI), using ultrasmall superparamagnetic iron oxide (USPIO) with new diagnostic criteria, in the evaluation of regional lymph node metastases in gastric cancer.MethodsThirty-one patients with gastric cancer were enrolled. 1000 lymph nodes were dissected during surgery, and of these, 519 nodes (51.9 %) were identified by currently used MRI imaging analysis. We evaluated lymph nodes on USPIO-post-contrast T2*-weighted images using the following two criteria: (1) we diagnosed the nodes on T2*-weighted images according to conventional criteria, where a node having an overall low signal intensity (pattern A) was nonmetastatic, while a node having partial (pattern B) or overall (pattern C) high signal intensity was metastatic; (2) we subdivided pattern B nodes on T1-weighted images using the new criteria, in which a node for which the high-intensity area on T2*-weighted images was not defined as adipose tissue on T1-weighted images (pattern B1) was metastatic, while a node for which the high-intensity area was defined as adipose tissue (pattern B2) was nonmetastatic.Results(1) The results using the conventional criteria were 96.2% sensitivity, 92.5% specificity, 76.3% positive predictive value (PPV), 99.0% negative predictive value (NPV), and 93.3% accuracy. (2) The results using the new criteria were 96.2% sensitivity, 98.3% specificity, 90.1% PPV, 99.0% NPV, and 97.1% accuracy.ConclusionThe assessment of lymph node metastases from USPIO-post-contrast MRI alone using the new criteria was useful in the diagnosis of regional lymph node metastases in gastric cancer.

Evaluation of combined docetaxel and nedaplatin chemotherapy for recurrent esophageal cancer compared with conventional chemotherapy using cisplatin and 5-fluorouracil: a retrospective study

This retrospective study evaluated the safety and efficacy of combination chemotherapy using docetaxel and nedaplatin in an outpatient setting compared with those of chemotherapy using cisplatin (CDDP) and 5-Fu under hospitalization. Subjects comprised 21 patients who had been diagnosed with recurrent esophageal squamous cell carcinoma (ESCC), with 10 patients receiving combination chemotherapy comprising CDDP and 5-fluorouracil (5-Fu) under hospitalization (FP group; n = 10), and 11 patients receiving combination chemotherapy comprising docetaxel and nedaplatin in an outpatient setting (Doc/Ned group; n = 11). In the Doc/Ned group, patients received 30 mg/m(2) of docetaxel over a 1-h infusion on day 1, followed by 40 mg/m(2) of nedaplatin over a 2-h infusion on day 1 in an outpatient setting. In the Doc/Ned group, complete response was observed in two patients (18.1%), one with liver metastasis and one with abdominal lymph node metastasis, and two (18.1%) achieved partial response. In contrast, no complete responses were obtained in the FP group, and partial response was observed in only one patient (10.0%) with local recurrence. Response rates were thus 36.3% for the Doc/Ned group and 10.0% for the FP group. With a median follow-up of 234 days in the Doc/Ned group and 279 days in the FP group, median survival time (MST) was 234 days in the Doc/Ned group and 378 days in the FP group. No significant differences in MST were identified between groups. Thus regimen based on docetaxel and nedaplatin allows administration on an outpatient basis and appears feasible for recurrent ESCC as a second-line chemotherapy.

Virtual CT gastrectomy by three-dimensional imaging using multidetector-row CT for laparoscopic gastrectomy

Key words: Virtual computed tomographic gastrec-tomy—Multidetector row computed tomogra-phy—Three-dimensional imaging—Multiphase fusionimaging—LaparoscopicgastrectomyLaparoscopicsurgeryhasgainedwideclinicalacceptancein various surgical practices and has become the goldstandard for cholecystectomy, Nissen fundoplication,and adrenal surgery. In 1994, the first laparoscopicallyassisted Billroth I gastrectomy was reported, and cur-rently a laparoscopic distal gastrectomy is commonlyperformedforearlystagegastriccancer[1].Thebenefitsof the laparoscopic approach include smaller surgicalincisions, less intraoperative blood loss, faster recoveryfor normal bowel function, and shorter hospital staysthaninthecaseofconventionalopensurgery[1–4].However, despite the advantages of this procedure,thereremainseveraldisadvantages:limitedimagesoftheentire operative field under laparoscopy and a lack oftactilesensationinterferewithdirectmanipulationbythesurgeonduringtheprocedure.Forthisreason,ittakesalongtimetoidentifythepropervesselswheretheremaybe major variations in each patient [2]. Moreover,arteriesrunalongoracrossveinsaroundthestomachina complicated fashion; therefore, veins can be injuredduring the dissection of lymph nodes along the arteriesandtheligationofarteriesunderlaparoscopicguidance,whichleadstoheavybleedingthatpreventsthesurgeonfromhavingaccesstoagoodviewoftheoperativefield[3].Therefore,itisquiteimportanttoperformapreop-erative assessment of vascular anatomy around thestomach using three-dimensional (3D) computed tomo-graphic(CT)angiography,whichcanbeveryhelpfultoachieve the safe and rapid ligation of vessels and dis-sectionoflymphnodes[5–9].We performed contrast-enhanced examinations atarterial and venous phase using 4 or 16 multidetector-rowCT(MDCT)beforealaparoscopicgastrectomyandslicedatafromtheindividualphaseswereconvertedintoa 3D imaging format using a volume-rendering tech-nique.Weusedthefusedimageof3Dimagesofarteriesand veins around the stomach for preoperative assess-ment and called the use of 3D imaging virtual CT gas-trectomy[5–9].In this study, we examined the usefulness of virtualCT gastrectomy for laparoscopic gastrectomy and,moreover, introduced our preliminary study of the vir-tualCTnavigationofsentinellymphnodes.

Giant fibrovascular polyp of the esophagus: MRI is useful for diagnosis and surgical planning

In the surgical field, benign esophageal tumors are much more uncommon than esophageal malignancies. In particular, fibrovascular polyps of the esophagus are extremely rare. We present a case involving a giant fibrovascular polyp (22 cm × 9 cm) in which not only location and site of origin but also precise polyp type were diagnosed preoperatively using magnetic resonance imaging (MRI). The lesion was then resected safely using a cervical approach. MRI is useful for acquiring valuable information about fibrovascular polyps. This case demonstrates the utility and safety of transcervical esophagotomy in the treatment of giant fibrovascular polyp of the esophagus.

CT and MR features of sclerosing mesenteritis mimicking a mesenteric metastasis from the carcinoid tumor

Sclerosing mesenteritis is a rare and benign inflammatory entity characterized by fibrofatty thickening of the mesentery. To our knowledge, there are only a few reports on the features of sclerosing mesenteritis on magnetic resonance (MR) imaging and computed tomography (CT). In this present case, MR imaging demonstrated tissue characterization of fibrosis, and partial maximum intensity projection (MIP) and three-dimensional angiography images obtained using multislice CT clearly revealed the extent of the tumor and the vascular appearance affected by the mass. However, a mesenteric metastasis from the carcinoid tumor may show such imaging features. Therefore, when encountering such a case, we suggest that a tentative diagnosis of sclerosing mesenteritis be made, followed by a biopsy for intraoperative histopathologic analysis to avoid aggressive surgery.