Neutrophil to Lymphocyte Ratio: A Predictive Marker for Treatment Outcomes in Patients With Rectal Cancer Who Underwent Neoadjuvant Chemoradiation Followed by Surgery

PURPOSE: In this study, we investigated the role of neutrophil to lymphocyte ratio (NLR) as a predictor of tumor response and as a prognostic factor in patients with rectal cancer who had undergone curative surgery after neoadjuvant chemoradiation therapy (nCRT). METHODS: Between January 2009 and July 2016, we collected 140 consecutive patients who had undergone curative intent surgery after nCRT due to rectal adenocarcinoma. We obtained the pre- and post-nCRT NLR by dividing the neutrophil count by the lymphocyte count. The cutoff value was obtained using receiver operating characteristic analysis for tumor response and using maximally selected rank analysis for recurrence-free survival (RFS). The relationship among NLR, tumor response, and RFS was assessed by adjusting the possible clinico-pathological confounding factors. RESULTS: The possibility of pathologic complete response (pCR) was significantly decreased in high pre- (>2.77) and postnCRT NLR (>3.23) in univariate regression analysis. In multivariate analysis, high post-nCRT NLR was an independent negative predictive factor for pCR (adjusted odds ratio, 0.365; 95% confidence interval [CI], 0.145–0.918). The 5-year RFS of all patients was 74.6% during the median 37 months of follow-up. Patients with higher pre- (>2.66) and post-nCRT NLR (>5.21) showed lower 5-year RFS rates (53.1 vs. 83.3%, P = 0.006) (69.2 vs. 75.7%, P = 0.054). In multivariate Cox analysis, high pre-nCRT NLR was an independent poor prognostic factor for RFS (adjusted hazard ratio, 2.300; 95% CI, 1.061–4.985). CONCLUSION: Elevated NLR was a negative predictive marker for pCR and was independently associated with decreased RFS. For confirmation, a large-scale study with appropriate controls is needed.

Imaging Findings of Scrotal Liposarcoma: A Case Report

Liposarcoma located in the scrotum is a very rare, and to our knowledge, only a few cases have been described in the radiologic literature. Clinically, scrotal liposarcoma manifests as a painless, slow-growing mass, which can be misdiagnosed as inguinal hernia, scrotal hydrocele or lipoma. Here, we present a case of scrotal liposarcoma. On CT and MRI, it manifested as a predominant fat-containing mass with heterogeneously enhancing soft tissue.

Evaluation of Mammographic Phantom Images Using JPEG2000 Image Compression

PURPOSE: To determine the usefulness of compression standard JPEG2000 for compression of mammographic images. MATERIALS AND METHODS: Image of a mammographic phantom was compressed using JPEG2000 at ratios of 10:1, 20:1, 30:1, 40:1, 50:1 and 60:1. The sizes of the images were compared, and scores were recorded by counting the numbers of fibers, groups of specks and masses seen in each phantom image. More than four fibers, three groups of specks and three masses and a total score of 10 were considered acceptable. RESULTS: The size of a DICOM image was 17,042 KB, a TIFF image was 8,324 KB, the original JPEG image was 1,506 KB and the most compressed image (50:1) above an acceptable total score of 10 was 43 KB. In each category, the compression image of fiber was acceptable up to compression ratio of 50:1 (score of 5), groups of specks was acceptable up to 60:1 (score of 3) and mass was acceptable up to 50:1 (score of 3.5). The total score, which was acquired by adding up the individual scores of all three categories, for a compression ratio of 50:1 was 12 and was acceptable, but the total score for 60:1 was 8 and was not acceptable. CONCLUSION: The compression standard JPEG2000 is an efficient means for compressing mammographic images at high ratios without compromising diagnostic value.

Small Cell Carcinoma of the Urinary Bladder: CT and MR Imaging Findings

OBJECTIVE: Primary small cell carcinoma (SCC) is a rare aggressive malignancy of the urinary bladder, with identical histopathology to that of the lung. The treatment and prognosis of bladder SCC are somewhat different from those of more frequent transitional cell carcinoma. The purpose of this study was to analyze the CT and MR imaging findings of bladder SCC. MATERIALS AND METHODS: Six adult patients (five males and one female) with pathologically proven SCC of the urinary bladder who had undergone pelvic CT and/or MR imaging were included in this study. The radiologic findings were retrospectively evaluated in terms of tumor location, texture, calcification, depth of invasion, perivesical extension, lymph node involvement, and local or distant metastasis, by two radiologists, who established a consensus. RESULTS: CT and MR images depicted all tumors as large, ill-defined, relatively well enhancing, broad-based polypoid intramural masses with (n=3) or without (n=3) cystic portions. Their frequent location was posterior and trigonal (n=3). Calcification was found within one tumor, and lymphadenopathy in four. At T2-weighted MR images, the solid portion of the tumor was relatively hypointense. The stage at the time of diagnosis was C in three patients, and D1 in three. Follow-up imaging showed brain metastasis in one patient and liver metastasis in two. CONCLUSION: On CT and MR images, SCC of the urinary bladder appeared as a large, enhancing, broad-based polypoid mass. It was stage C or higher, and lymph nodes and distant metastasis were frequent. T2-weighted MR images showed that the solid portion of the tumor was relatively hypointense. When radiologic examinations demonstrate a bladder tumor of this kind in adults, SCC of the urinary bladder should be included in the differential diagnosis.

Pelvic Cavernous Hemangioma / 대한비뇨기과학회지

The majority of hemangiomas are small, benign vascular tumors. They can regress spontaneously as a result of fibrosclerosis, suggesting a conservative approach whenever possible. They require little, if any, treatment and are easy to differentiate from malignant tumors clinically and radiologically, and there is no evidence that hemangiomas ever become malignant. We report a case of a 54-year old man with extravesical cavernous hemangioma who was diagnosed with a malignant tumor preoperatively.

MR Findings of Ossifying Fibroma with Pathologic Correlation

PURPOSE: To compare the MR imaging findings of ossifying fibroma with the histopathologic findings. MATERIALS AND METHODS: In eight patients (M:F=1:7; age range, 1-25 years) with pathologically proven ossifying fibroma, plain film and MR images were retrospectively analyzed in terms of signal intensity, homogeneity and patterns of contrast enhancement. The MR imaging findings and histopathology were correlated. Using 1.0-T and 1.5-T MR machines, axial T1 and T2 images and gadolinium-enhanced axial and sagittal T1 images were obtained. RESULTS: In all cases, iso-signal intensity to muscle was observed on T1-weighted images, and high signal intensity on T2-weighted images. After intravenous injection of gadolinium-DTPA in seven cases, intense contrast enhancement was seen in all lesions, which were homogenous on T1, T2, and enhanced MR images. Moderate cellularity of fibrous tissue, with even distribution of osteoid and an absence of secondary changes such as hemorrhage or cystic change were revealed by pathologic examination. CONCLUSION: Ossifying fibroma shows strong enhancement and homogenous signal intensity on MR images.The homogeneity of the MR signal depends on the even distribution of osteoid and an absence of secondary changes such as hemorrhage or cystic change.

Necessity and Safety of Fine-needle Aspiration Cytology for Diagnosis of Hepatocellular Carcinoma / 대한간학회지

BACKGROUNDS/AIMS: The fine-needle aspiration (FNA) is a useful method for diagnosis of hepatocellular carcinoma (HCC). The aims of our study are to assess diagnostic accuracy of FNA, to define proper indications of FNA for diagnosis of HCC, and to evaluate the complications of FNA. SUBJECTS AND METHODS: To assess diagnostic accuracy we compared the results of preoperative FNA with postoperative pathology in 38 resected cases with primary liver cancer. To define proper indications and complications of FNA, we prospectively followed 138 patients received FNA for their liver tumors which were suspicious of primary liver tumor. RESULTS: The sensitivity, specificity, positive and negative predictive values of FNA were 100%, 97%, 100% and 66% respectively. All patients with serum alpha-fetoprotein (AFP) level over 1000 ng/ml were having HCC on FNA result. Among 36 patients with AFP level ranged 15-1000 ng/ml and hypervascular mass on angiography, 96% were having HCC. Among 50 patients with normal AFP level and hypervascular mass on angiography, 92% were having HCC. The major complications after FNA such as hemoperitoneum, pneumothorax, and iatrogenic arterioportal shunt developed in 2%, 2%, and 7% of subjects, respectively. We did not find any case of needle-tract seeding of cancer during a mean 4.7 months of follow-up. CONCLUSIONS: Although the FNA is an accurate method for diagnosis of HCC, FNA was usually not indicated for patients with serum AFP level over 1000 ng/ml or patients with hypervascular mass on angiography when they were suspected of having primary liver cancer. Major complications were hemoperitoneum, pneumothorax and iatrogenic arterioportal shunt. Iatrogenic arterioportal shunt may influence the efficacy of subsequent transcatheter arterial embolization.

CT and US Findings of Multilocular Cystic Renal Cell Carcinoma

OBJECTIVE: Multilocular cystic renal cell carcinoma (MCRCC) is a recently described variety of renal cell carcinoma with characteristic pathologic and clinical features. The purpose of this study was to analyze the imaging findings of MCRCCs. MATERIALS AND METHODS: Ten adult patients with pathologically proven unilateral MCRCC who underwent renal US and CT were included in this study. The radiologic findings were retrospectively evaluated for cystic content, wall, septum, nodularity, calcification and solid portion by three radiologists who established a consensus. Imaging and postnephrectomy pathologic findings were compared. RESULTS: All patients were adults (six males and four females) and their ages ranged from 33 to 68 years (mean, 46). On US and CT images, all tumors appeared as well-defined multilocular cystic masses composed of serous or complicated fluid. In all patients, unenhanced CT scans revealed hypodense cystic portions, and in four tumors, due to the presence of hemorrhage or gelatinous fluid, some hyperdense areas were also noted. In no tumor was an expansile solid nodule seen in the thin septa, and in only one was there dystrophic calcification in a septum. Small areas of solid portion constituting less than 10% of the entire lesion were found in six of the ten tumors, and these areas were slightly enhanced on enhanced CT scans. In all patients, imaging and pathologic findings correlated closely. CONCLUSION: On US and CT images, MCRCC appeared as a well-defined multilocular cystic mass with serous, proteinaceous or hemorrhagic fluid, with no expansile solid nodules in the thin septa, and sometimes with small slightly enhanced solid areas. Where radiologic examinations demonstrate a cystic renal mass of this kind in adult males, MCRCC should be included in the differential diagnosis.

CT and US Findings of Multilocular Cystic Renal Cell Carcinoma

OBJECTIVE: Multilocular cystic renal cell carcinoma (MCRCC) is a recently described variety of renal cell carcinoma with characteristic pathologic and clinical features. The purpose of this study was to analyze the imaging findings of MCRCCs. MATERIALS AND METHODS: Ten adult patients with pathologically proven unilateral MCRCC who underwent renal US and CT were included in this study. The radiologic findings were retrospectively evaluated for cystic content, wall, septum, nodularity, calcification and solid portion by three radiologists who established a consensus. Imaging and postnephrectomy pathologic findings were compared. RESULTS: All patients were adults (six males and four females) and their ages ranged from 33 to 68 years (mean, 46). On US and CT images, all tumors appeared as well-defined multilocular cystic masses composed of serous or complicated fluid. In all patients, unenhanced CT scans revealed hypodense cystic portions, and in four tumors, due to the presence of hemorrhage or gelatinous fluid, some hyperdense areas were also noted. In no tumor was an expansile solid nodule seen in the thin septa, and in only one was there dystrophic calcification in a septum. Small areas of solid portion constituting less than 10% of the entire lesion were found in six of the ten tumors, and these areas were slightly enhanced on enhanced CT scans. In all patients, imaging and pathologic findings correlated closely. CONCLUSION: On US and CT images, MCRCC appeared as a well-defined multilocular cystic mass with serous, proteinaceous or hemorrhagic fluid, with no expansile solid nodules in the thin septa, and sometimes with small slightly enhanced solid areas. Where radiologic examinations demonstrate a cystic renal mass of this kind in adult males, MCRCC should be included in the differential diagnosis.

28 Cases of Metastatic Tumors to the Kidney / 대한비뇨기과학회지

No abstract available.

Diagnosis of Superficial Esophageal Cancer: Comparative Study of Double Contrast Esophagography and Endoscopy

PURPOSE: To assess the diagnostic accuracy and limitations of double contrast esophagography in patients with superficial esophageal cancer, as compared with endoscopic, gross and microscopic findings. MATERIALS AND METHODS: In 43 patients with pathologically proven superficial esophageal cancer, the detection rate and diagnostic accuracy of double contrast esophagography and endoscopy were compared. The depth of invasion revealed by esophagography, and grossly and microscopically in resected specimens, was compared. RESULTS: The detection rate and diagnostic accuracy were, respectively, 86.0% and 76.7% for esophagography, and 100% and 95.3% for endoscopy. In addition, very different detection rates (54.6% and 100%, respectively) were noted for epithelial and mucosal lesions. In flat-type cases (0-IIb), esophagography showed limited ability to detect lesions, but the accuracy of this modality in predicting the depth of tumor invasion was relatively high (94.6%). CONCLUSION: In cases of superficial esophageal cancer, double contrast esophagography showed a lower detection rate and lower diagnostic accuracy than endoscopy, and this was especially so for epithelial and mucosal lesions. The modality was able, however, to reliably predict the depth of tumor invasion.

Diagnosis of Recurrent Uterine Cervical Cancer: Computed Tomography versus Positron Emission Tomography

OBJECTIVE: To determine the accuracy of CT and positron emission tomography (PET) in the diagnosis of recurrent uterine cervical cancer. MATERIALS AND METHODS: Imaging findings of CT and PET in 36 patients (mean age, 53 years) in whom recurrent uterine cervical cancer was suspected were analyzed retrospectively. Between October 1997 and May 1998, they had undergone surgery and/or radiation therapy. Tumor recurrence was confirmed by pathologic examination or follow-up studies. RESULTS: In detecting recurrent uterine cervical cancer, the sensitivity, specificity, and accuracy of CT were 77.8%, 83.3%, and 80.5%, respectively, while for PET, the corresponding figures were 100%, 94.4%, and 97.2%. The Chisquare test revealed no significant difference in specificity (p = .2888), but significant differences in sensitivity (p = .0339) and accuracy (p = .0244). CONCLUSION: PET proved to be a reliable screening method for detecting recurrent uterine cervical cancer, but to determine the anatomical localization of recurrent tumors, and thus decide an adequate treatment plan, CT was eventually needed.

CT Findings of Pleural Dissemination from Lung Cancer

PURPOSE: The purpose of our study was to identify the CT findings that help detect pleural dissemination from lung cancer and to evaluate the usefulness of selected diagnostic criteria. MATERIALS AND METHODS: After a computerized database search of 606 patients who had undergone thoracotomy for primary lung cancer, 23 patients were identified as h aving surgically documented pleural dissemination. From the same database, 50 patients without pleural dissemination during thoracotomy were randomly selected as controls. Preoperative CT scans and medical records were rev i ewed retrospectively, and findings were compared between the two groups. RESULT: One or more of three types of pleural thickening (plaque-like, nodular, and fissural) were identified on CT as the most discriminating finding (sensitivity, 74 % ; specificity, 60 %; p = 0.007). The following findings were also significantly discriminating (p<0.05): contiguity of primary tumor with the pleural surface as seen on CT; adenocarcinoma in cell type; and a peripheral tumor defined as one in which bronchoscopy revealed no endobronchial lesion. The use of combinations of these findings in addition to pleural thickening rendered diagnostic criteria more specific at the cost of the sensitivity. CONCLUSION: During preoperative CT evaluation of lung cancer, the recognition of subtle pleural thickening helps detect pleural dissemination. The likelihood that subtle pleural thickening represents pleural dissemination is increased when a primary tumor is contiguous with the pleural surface, is an adenocarcinoma, or is peripherally located.

MR Imaging Findings of Chondroblastic Osteosarcoma

PURPOSE: To evaluate the MR imaging findings of chondroblastic osteosarcoma. MATERIALS AND METHODS: Weincluded 11patients (8 men, 3 women, mean age of 19 years) with pathologically proven chondroblastic osteosarcomaand, as a control group, 20 patients with conventional osteosarcoma. We obtained pre- and post-enhanced MR imagesof all patients and retrospectively reviewed the signal intensity and enhancement pattern of tumors. MR imageswere correlated with histopathology. RESULT: In chondroblastic osteosarcomas, the major portion (< 75%) of thetumor showed low signal intensity on T1-weighted images and homogeneous high signal intensity on T2-weightedimages, but did not show enhancement. The margin of the area showed a lobular pattern. Enhanced nodules (n=11) andstrands (n=8) were seen in the nonenhanced portion. Histopathologically, the nonenhanced portion, nodules, andstrands revealed a chondroid matrix, hypercellular area, and fibrovascular septa, respectively. Conventionalosteosarcomas showed heterogeneous enhancement ; six showed a focal (<25%) nonenhanced area representing necrosis. CONCLUSION: Chondroblastic osteosarcoma showed characteristic MR imaging findings.

Osteosarcoma after Preoperative Chemotherapy: Tissue Characterization with Specimen MR and the Role of Enhanced MR Imaging

PURPOSE: To evaluate the role of enhanced MR imaging in monitoring tumor response to preoperativechemotherapy for osteosarcomas. MATERIALS AND METHODS: Fo r t y - s even patients (30 males and 17 females, witha mean age 17 years ; range 8 -44 years) with osteosarcomas were included in this study. We obtained spin echoT1-, T2-, and enhanced T1-weighted images before and after pre-operative chemotherapy and in all patientscorrelated changes in MR parameters with histopathologic response. We also obtained 19 specimen MR images,correlating these with histopathologic results in order to estimate tissue specific signals. Patients with morethan 10% viable tumor in the resected specimen were considered poor respon-ders(n=26), while those with 10% orless viable tumor were considered good respon-ders(n=21). RESULTS: Four distinct patterns of signal intensitycorresponded, respectively to dead bone and dense fibrosis (low on T1- and T2-weighted images), viable tumor cells(in-termediate on T1- and high on T2-weighted images), necrosis (low on T1- and high on T 2 - weighted images),and hemorrhage (high on T1- and T2-weighted images), but a wide range of overlap was noted. In all four groups,viable tumor cells remained. Increased tumor vo l u m e, stable or increased edema and enhancement were goodpre-dictors of poor response (predictive values of 83%, 77%, and 89%, respectively). Decreased enhancement was theonly reliable predictor of good response (predictive value, 73%). Changes in tumor margin, homogeneity, signalintensity, and joint effu-sion did not correlate with histopathologic response. CONCLUSION: Signal intensities donot reflect histologic nature. Enhanced MR imaging is a useful predictor of tumor response to preoperativechemotherapy.

MR Imaging of Osteosarcoma: Emphasis on Joint Involvment

PURPOSE: To evaluate MR imaging findings of joint involvement in patients with osteosarcoma MATERIALS AND METHODS: Among 166 patients with osteosarcoma treated between January 1993 and July 1998, 67(44 men and 23 women,mean age 20 years) whose tumors had invaded the epiphysis were included in this study. Those with preserved normalbone marrow signal intensity between the tumor and cortical bone were excluded. Tumors were located around theknee (n=52), the hip (n=7), the shoulder (n=5), the ankle (n=2), or the wrist (n=1). For all patients,pre-operative spin echo pre- and post-contrast enhanced MR images were obtained. In all cases, we assessed thepresence or abscence of intrasynovial mass, intraarticular disruption of cortical bone and articular cartilage,and joint effusion, and also evaluated the mass around the cruciate ligaments of the knee. All patients underwentsurgery and MR findings were correlated with the results of pathologic examinations. RESULTS: In six patients thetumor was found to involve the knee joint. Sensitivity and specificity for the intrasynovial mass (n= 6),intraarticular disruption of cortical bone and articular cartilage (n= 19), mass around the cruciate ligaments (n=7), and joint effusion (n= 12) were 83.3%, 100%, 83.3%, 33.3% and 98.4%, 78.7%, 95.6%, 83.6%, respectively, whileaccuracy for the intrasynovial mass and mass around the cruciate ligaments was 97% and 94.2% respectively. CONCLUSION: If MR imaging indicates the presence of a mass in the synovial cavity or around the cruciateligaments, this is suggestive MR findings of joint involvement.

Liposarcoma: MR Findings in the Histologic Subtypes

PURPOSE: To evaluate the MR imaging findings of liposarcomas of different histologic subtypes. MATERIALS AND METHODS: We evaluated MR images of 21 patients (5 men and 16 women, mean age, 55 years) with liposarcoma andcorrelated the findings with the results of histopathology. In the study group seven liposarcomas werewell-differentiated, seven were myxoid, three were mixed, two were pleomorphic, and one was round cell. RESULTS: On T1 -and T2 - weighted images, six of seven well-differentiated liposarcomas showed signal intensity equal tothe fat and hypointense septa, while the other showed low signal intensity on a T1 -weighted image, heterogeneoushigh signal intensity on a T2- weighted image, heterogeneous enhancement after the administration of contrastmedia and was dedifferentiate. Nine masses in seven patients with myxoid liposarcoma showed low signal intensityon T1-weighted images, six of the nine showed lace-like foci of high signal intensity. On T2 -weighted images, allmasses showed homogeneous high signal intensity. After administration of contrast media, five of seven massesshowed heterogeneous enhancement. Two of three mixed form were well-differentiated and myxoid types, and twosubtypes were separable on MR. Pleomorphic, round cell, mixed type myxoid and pleomorphic and unclassified casesshowed low signal intensity on T1-weighted images, heterogeneous high signal intensity on T2-weighted andheterogeneous enhancement. CONCLUSION: Using MR imaging, well-differentiated and myxoid liposcarcomas may bedifferentiated from other types.

Evaluation of Mediastinal Lymph Node Metastasis in Lung Cancer: Factors influencing the Diagnostic Accuracy ofCT

PURPOSE: To evaluate factors influencing the CT assessment of mediastinal lymph node metastasis in patientswith non-small cell lung cancer. MATERIALS AND METHODS: CT scans of 198 patients who had undergone thoracotomyand mediastinal lymph node dissection for non-small cell lung cancer were retrospectively evaluated using a sizecriterion of > or = 10mm in the short axis. To evaluate the accuracy of CT in diagnosing lymph node metastasis on anodal station-by-station basis, CT and pathological results were correlated. Analysis included a comparison of thesensitivity and specificity of CT according to 1) cell type of tumor, squamous cell carcinoma versusadenocarcinoma (excluding bronchioloalveolar cell carcinoma) ; 2) histologic differentiation;3) tumor size;4)central and peripheral of the tumor;5) the presence or absence of obstructive pneumonitis and/or atelectasis;6)the presence or absence of prior granulomatous disease. RESULTS: The overall sensitivity, Specificity, positive predictive value, and negative predictive value of CT in diagnosing mediastinal lymph node metastasis were 65%,84%, 43%, and 93%, respectively. Sensitivity for squamous cell carcinoma (72%) was significantly higher than thatfor adenocarcinoma(44%)(p<0.01). Higher specificities were noted in patients without obstructive pneumonitisand/or atelectasis(91% versus 75%)(P<0.01), and with a peripherally located tumor (90% versus 82%)(P<0.01).sensitivity and specificity were not appreciably altered by other variables. CONCLUSION: In the CT assessment ofmediastinal lymph node metastasis the cell type of adenocarcinoma adversely affected sensitivity, with a highfrequency of normal-sized metastatic nodes. Obstructive pneumonitis caused by central tumor adversely affectedspecificity with the frequent occurrence of hyperplastc nodes.

Effect of Intraarterial and Systemic Chemotherapy for Stage IIb Cervical Carcinoma: Assessment of TherapeuticResponse Using MR Imaging

PURPOSE: To evaluate the effectiveness of intraarterial chemotherapy(IAC) and systemic chemotherapy(SC) incases of locally advanced cervical carcinoma, and to assess the accuracy of magnetic resonance(MR) imaging fordetermining parametrial invasion after IAC or SC. MATERIALS AND METHODS: Among 44 patients with stage IIbcervical carcinoma, IAC was performed in 25 and SC in 19. MR images obtained before and after IAC or SC wereprospectively analyzed with regard to tumor volume and parametrial invasion, and tumor response to chemotherapywas classified as complete, partial, or progressive. Forty-one patients underwent radical hysterectomy within twoweeks of the second MR examination, and postoperative pathologic findings were correlated with radiologicfindings. RESULTS: The average reduction rate of tumor volume in the IAC and SC group was 89.2% and 66.3%,respectively. Between the two groups, there was no statistically significant difference(P>0.05). In the IAC group,13 patients showed a complete response and 11 a partial response, and in one there was progression. In the SCgroup, eight patients showed a complete response and nine a partial response, and in two there was progression.The accuracy of MR imaging for determining parametrial invasion after chemotherapy was 87.8%. In each patientthere was close correlation between MR imaging and pathologic findings. CONCLUSION: There was no statisticallysignificant difference in tumor reduction between the IAC and SC group. After chemotherapy for stage IIb cervicalcarcinoma, MR imaging is a valuable modality for determining surgical candidates.

Mechanical Characteristics of Self-expandable Metallic Stents: In Vitro Study with Three of Stress

PURPOSE: To obtain objective and comparable date for mechanical characteristics of self-expandable metallicstents widely used in the treatment of biliary obstruction. MATERIALS AND METHODS: The stents tested were the 6and 9 mm-band Hanaro spiral stent, Gianturco-R sch Z stent, Wallstent, Ultraflex stent, and Memotherm stent. Eachwas subjected to three types of load : point, area, and circular. We analyzed their mechanical characteristics(resistance force, expansile force, and elasticity) according to these three types of stress. RESULTS: Withregard to point loads, the Memotherm stent showed the highest resistance force and expansile force. The 8 mm-bandhanaro stent showed the lowest resistance force and the Gianturco-R sch Z stent and Ultraflex stent showed lowerexpansile force. With regard to area loads, the Ultraflex stent showed the highest resistance force. The 6 mm-bandHanaro stent, Gianturco-R sch Z stent, and Ultraflex stent showed higher expansile force. The 8 mm-band Hanarostent showed the lowest value in both resistance force and expansile force. For circular loads, the Memothermstent showed the highest resistance force and the Ultraflex stent and Wallstent showed lower Value. Under alltypes of stress, the Hanaro stent and Memotherm stent were completel elastic, and the Ultraflex stent andWallstent showed a wide gap between resistance force and expansile force. CONCLUSION: In clinical practice,awareness of the mechanical characteristics of each stent might help in choosing the one which is most suitable,according to type of biliary obstruction.