Koichi Shirono

Kyoto Prefectural University of Medicine, Kioto, Kyoto, Japan

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Publications (6)7.91 Total impact

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    ABSTRACT: Dynamic contrast-enhanced magnetic resonance imaging (CE-MRI) has emerged as a promising diagnostic modality in various breast cancer treatments. However, little is known about the correlation between the pattern of time to signal intensity curves (TIC) on the CE-MRI and clinicopathologic features. This study was designed to investigate these correlations and evaluate the predictive value of TIC on CE-MRI in order to identify high-risk patients. Between 2001 and 2003, 101 lesions were evaluated to detect malignancy on CE-MRI in 101 women who were suspected of having breast tumors based on either clinical findings or conventional imaging studies. Moreover, the clinicopathologic findings were compared with the pattern of TIC for the 69 surgically treated malignant lesions. In detecting malignancy, the sensitivity, specificity, and accuracy were 78.7%, 88.5%, and 81.2%, respectively, in the 101 breast lesions. Especially for the 69 surgically treated malignant lesions, in comparison with breast cancer tumors with the benign pattern of TIC, the breast cancer tumors with a malignant pattern were found more frequently in lymphatic invasion (P < 0.01) and lymph node metastasis (P < 0.005), although no statistical correlation regarding the histological type, tumor size, vascular invasion, extensive intraductal component, hormone receptor status, or pathological stage was noted between the two groups. According to a logistic regression model, lymph node metastasis was found to be a significant independent variable. The pattern of TIC could be used to predict lymphatic spreading associated with lymph node metastasis prior to surgery as well as to detect malignancy. Therefore, a more detailed evaluation should be made to identify the presence of lymphatic spreading in patients with a malignant pattern of TIC.
    No preview · Article · Aug 2005 · Surgery Today
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    ABSTRACT: We encountered a case of occult contralateral breast cancer, previously undetected by conventional imaging such as mammography (MMG) and ultrasonography (US), but incidentally detected by contrast-enhanced magnetic resonance imaging (CE-MRI). We present it here with a review of the literature. A 67-year-old Japanese woman was referred to our hospital in October 2000 because of a 1.5 cm right breast lump detected in a medical checkup. MMG, US and fine needle aspiration cytology revealed a cancerous lesion during the right breast. No mass lesion was palpable nor was any detected by MMG or US in the left breast. Bilateral breast CE-MRI was performed for more detailed evaluation. Consequently, an occult contralateral breast cancerous lesion was detected incidentally by CE-MRI, with the images showing rapid initial enhancement of time to signal intensity curves. Before surgery, bilateral breast lesions were diagnosed as invasive ductal carcinoma by open biopsy. She underwent bilateral breast conserving surgery with bilateral axillary lymph node dissection. The postoperative course was uneventful and no recurrence has been noted as of January 18th, 2004. CE-MRI of the contralateral breast should be of value as a routine screen in those patients with a known or suspected malignancy in one breast considering the limits of breast cancer detection by such conventional modalities as MMG and US.
    No preview · Article · Feb 2005 · Breast Cancer
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    ABSTRACT: Contrast-enhanced magnetic resonance imaging (CE-MRI) has emerged as a new diagnostic technology in various breast cancer treatments. However, little is known about the correlation between intraductal spread on CE-MRI and clinicopathologic features. This study was designed to evaluate these correlations for the surgical planning of breast cancer. Twenty-six breast cancer lesions (in 26 female patients) treated by breast conserving surgery between March 2001 and March 2003 were evaluated retrospectively. CE-MRI was performed with a 1.5 T unit using a dedicated bilateral breast coil. In detecting intraductal spread of breast cancer, the sensitivity, specificity and accuracy of CE-MRI were 82.4%, 60.0% and 77.3%, respectively. On mammography (MMG), these were 21.1%, 100.0% and 42.3%, respectively. Therefore, CE-MRI has a higher sensitivity and accuracy, although with a lower specificity than MMG. Compared with breast cancer lesions without intraductal spread on CE-MRI, lesions with intraductal spread on CE-MRI were found more frequently in larger-sized tumors (P = 0.0088). Preoperative evaluation for intraductal spread by CE-MRI should be more useful than by MMG for breast cancer. When making the surgical decision regarding excision range, particular attention should be paid to this consideration for patients with larger-sized cancer tumors.
    Preview · Article · Oct 2004 · Japanese Journal of Clinical Oncology
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    ABSTRACT: The reduction in the incidence of severe postoperative complications has resulted in a significant increase in the survival of patients with gastric cancer. A total of 879 patients undergoing gastrectomy for gastric cancer during the last decade were retrospectively evaluated for postoperative complications, mortality and associated risk factors. The most frequent complications were anastomotic leakage (3.0%) and wound infection (2.8%) followed by the development of pancreatic fistulae (2.2%) and intra-abdominal abscesses (1.5%). Multiple logistic regression analysis identified various independent risk factors including the extent of lymph node dissection (D1D2 vs. D3) for anastomotic leakage (RR 3.6, P<0.05), splenectomy or distal pancreatosplenectomy for pancreatic fistulae (RR 27.4, P<0.0001) and operative time (360 min < or =) for intra-abdominal abscess (RR 4.8, P<0.05). In total, fourteen patients (1.6%, n=879) died from postoperative complications, with 5 patients dying following non-curative gastrectomy (5.6%, n=90). The complications most associated with death were anastomotic leakage (4 patients) and pneumonia (2 patients). In view of the potential risk of complications, we should carefully evaluate the indications for aggressive lymph node dissection and/or combined resection of neighboring organs as well as non-curative gastrectomy.
    No preview · Article · Mar 2004 · Hepato-gastroenterology
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    ABSTRACT: The latest TNM classification (5th edition) changed the definition of nodal staging from the anatomical localization to the total number of metastatic lymph nodes. This study was designed to evaluate and compare the prognostic significance of nodal staging between the two widely known staging systems, the TNM classification (TNM) and Japanese Classification for Gastric Cancer (JCGC). A total of 582 patients who underwent curative gastrectomy with extended lymphadenectomy for gastric cancer were reviewed retrospectively from hospital records. Based on the localization of metastatic nodes according to the JCGC and the total positive node number according to TNM, the patients were divided into subgroups and their prognoses compared. Lymph node metastasis was found in 189 of the 582 patients (32.5%). Both nodal staging systems were found to be significant prognostic factors by multivariate analysis. A prognostic analysis of the patients by subdivision with the two staging systems indicated that the nodal staging system in TNM was more homogenous than that of the JCGC. The nodal staging system of the TNM classification is superior to that of the Japanese Classification of Gastric Cancer, because it is simple, reproducible and homogeneous.
    No preview · Article · Jan 2003 · Hepato-gastroenterology
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    ABSTRACT: Recent advances in diagnostic techniques have led to the detection of an increasing number of early gastric cancers in the upper third of the stomach. The objective of this study was to determine the most appropriate surgical treatment for these cancers. The clinicopathologic characteristics of 35 patients with early gastric cancer in the upper third of the stomach who underwent three different types of gastrectomies were reviewed retrospectively from hospital records between January 1992 and August 1999. Patients undergoing limited proximal gastrectomy with esophagogastrostomy reconstruction had shorter operation times and less blood loss than those for patients undergoing total gastrectomy or proximal gastrectomy with jejunal interposition. No lymph node metastasis was identified in any of these patients. Heartburn due to reflux esophagitis was seen in a few patients of each group, but they were successfully treated by antacids. The extreme reduction in food intake volume was more frequently experienced in patients with total gastrectomy than those with both proximal gastrectomies. When mortality due to other disease was excluded, all patients survived without recurrence. A limited proximal gastrectomy with esophagogastrostomy reconstruction decreased surgical risk and realized preservation of maximal function.
    No preview · Article · Jan 2001 · Hepato-gastroenterology

Publication Stats

94 Citations
7.91 Total Impact Points


  • 2005
    • Kyoto Prefectural University of Medicine
      • Division of Digestive Surgery
      Kioto, Kyoto, Japan
  • 2001-2005
    • Kyoto Daini Red Cross Hospital
      Kioto, Kyōto, Japan