Preoperative Detection of Hepatic Metastases from the colorectal Cancers: Comparison of Dual-phase CT scan, Mn-DPDP enhanced MRI, and combination of CT and MRI

PURPOSE: To determine the usefulness of additional Mn-DPDP MRI for preoperative evaluation of the patients with colorectal cancers by comparison of dual-phase CT scan, Mn-DPDP enhanced MRI and combination of CT and MRI. MATERIALS AND METHODS: Fifty-three colorectal cancer patients with 92 metastatic nodules underwent dualphase (arterial and portal) helical CT scan and Mn-DPDP MRI prior to surgery. The indication of MRI was presence or suspected of having metastatic lesions at CT scan and/or increased serum carcinoembryonic antigen (CEA) levels (10 ng/mL or more). The diagnosis was established by the combination of findings at surgery, intraoperative ultrasonography, and histopathologic examination. Two radiologists interpreted CT, MRI, and combination of CT-MRI at discrete sessions and evaluated each lesion for location, size, and intrinsic characteristics. The lesions were divided into three groups according to their diameter; 1cm 2 cm. Diagnostic accuracy was evaluated using the alternative-free response receiver operating characteristic method. Detection and false positive rate were also evaluated. RESULTS: In the lesions smaller than 1 cm, detection rate of combined CT-MRI was superior to CT or MRI alone (82%, p = 0.036). The mean accuracy (Az values) of combined CT and MRI was significantly higher than that of CT in the lesions smaller than 2 cm (1 cm <, p=0.034; 1-2 cm, p=0.045). However, there was no significant difference between MRI and combined CT-MRI. The false positive rate of CT was higher than those of combined CT-MR in the lesions smaller than 1 cm (28 %, p=0.023). CONCLUSION: Additional MRI using Mn-DPDP besides routine CT scan was helpful in differentiating the hepatic lesions (< 2 cm) and could improve detection of the small hepatic metastases (< 1 cm) from colorectal carcinoma.

The Surgeon's Expertise-Outcome Relationship in Gastric Cancer Surgery / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The surgical caseload or duration of practice of a surgeon may influence the outcomes of gastric cancer surgery. This study aimed to clarify the surgical quality provided by specialized gastric cancer surgeons. MATERIALS AND METHODS: The postoperative courses of 1, 877 patients who underwent surgery for gastric cancer were retrospectively reviewed. For classification of the surgeon's expertise, the number of yearly resections performed by, and consecutive years of practice of, the surgeons were used. The outcome measures used were the 30-day mortality and long-term survival. RESULTS: Surgical mortalities of patients who underwent surgery by a specialized surgeon and those by a general surgeon revealed no statistically significant difference. A significant difference in the five-year survival rates was found with surgeons with at least two consecutive years of practice compared to those with less than two years, when 50 or more cases had been conducted per year (63.9% and 59.7%; p=0.0380). In cases of four-years of consecutive practice, the five-year survival rate was significantly improved, even if only 10 cases were performed annually (64.9% and 58.3%; p=0.0023), although the best survival rate was found with surgeons that had performed 50 or more surgeries per year. CONCLUSION: Improved survival rates, with acceptable surgical mortality, can be achieved for gastric cancer when the surgery is performed by a specialized surgeon. A specialized gastric cancer surgeon can be defined as one who has operated on more than 50 new cases per year, with 2 or more consecutive years of surgical practice.

Quantitative Analysis of Metastatic Lymph Nodes after Curative Surgery in Gastric Cancer / 대한암학회지

PURPOSE: A consecutive series of 710 patients who underwent curative gastrectomy for carcinoma was studied with a special reference to the number or frequency of lymph node metastasis and the patient's prognosis. MATERIAL AND METHODS: Survival rates were calculated by the Kaplan-Meier method, and the difference between each group was evaluated statistically by the log-rank method. Follow-up was obtained for 709 patients (99.9%). RESULTS: According to the number of lymph nodal metastases, the five year survival rate for group 1 (1~3 positive nodes) was 50.9%; for group 2 (4~6 positive nodes), 56.7%; and for group 3 (more than 6 positive nodes), 12.0% (p<0.0001). According to the frequency of lymph node metastases, the five year survival rate for those with up to 25 per cent frequency of metastases was 47.5%; for those with up to 50 per cent frequency of metastases, 15.6%; and for those with greater than 50 per cent metastases, 6.3% (p<0.0001). According to the frequency of the regional lymph nodes (which include perigastric nodes along the lesser and greater curvatures, nodes located along the left gastric, common hepatic, splenic, and celiac arteries) metastasis, we categorized them as group 0 (N0: no metastasis), 1 (N1: metastasis in up to 25%), and 2 (N2: metastasis in greater than 25%). CONCLUSION: This subdivision could be successfully applied to the clinical evaluation of gastric carcinoma (five year survival rate for N0, 86.9%; for N1, 49.0%; and for N2, 10.7% (p<0.0001)) without difficulty in dividing certain lymph nodes into the correct location.