Sung Il Hwang

Trastuzumab-Conjugated Liposome-Coated Fluorescent Magnetic Nanoparticles to Target Breast Cancer

Objective To synthesize mesoporous silica-core-shell magnetic nanoparticles (MNPs) encapsulated by liposomes (Lipo [MNP@m-SiO2]) in order to enhance their stability, allow them to be used in any buffer solution, and to produce trastuzumab-conjugated (Lipo[MNP@m-SiO2]-Her2Ab) nanoparticles to be utilized in vitro for the targeting of breast cancer. Materials and Methods The physiochemical characteristics of Lipo[MNP@m-SiO2] were assessed in terms of size, morphological features, and in vitro safety. The multimodal imaging properties of the organic dye incorporated into Lipo[MNP@m-SiO2] were assessed with both in vitro fluorescence and MR imaging. The specific targeting ability of trastuzumab (Her2/neu antibody, Herceptin®)-conjugated Lipo[MNP@m-SiO2] for Her2/neu-positive breast cancer cells was also evaluated with fluorescence and MR imaging. Results We obtained uniformly-sized and evenly distributed Lipo[MNP@m-SiO2] that demonstrated biological stability, while not disrupting cell viability. Her2/neu-positive breast cancer cell targeting by trastuzumab-conjugated Lipo[MNP@m-SiO2] was observed by in vitro fluorescence and MR imaging. Conclusion Trastuzumab-conjugated Lipo[MNP@m-SiO2] is a potential treatment tool for targeted drug delivery in Her2/neu-positive breast cancer.

Superior Labral Anteroposterior Tears: Accuracy and Interobserver Reliability of Multidetector CT Arthrography for Diagnosis

PURPOSE To evaluate the accuracy and interobserver reliability of multidetector computed tomographic (CT) arthrography for the diagnosis and classification of superior labral anteroposterior (SLAP) lesions. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained. Retrospective review of images from 161 multidetector CT arthrographic examinations was performed by two radiologists independently for detection and classification of SLAP lesions (type I-X), and sensitivity, specificity, accuracy, and interobserver agreement were evaluated. RESULTS The SLAP group included 94 patients, and the no-SLAP group included 67 patients with normal labrum. At arthroscopy, a total of 88 SLAP lesions (excluding type I) were found. For detection of SLAP lesions excluding SLAP type I lesions, sensitivity, specificity, and accuracy were 94.3%, 76.7%, and 86.3% for reader 1 and 97%, 72.6%, and 86.3% for reader 2, respectively, and the interobserver agreement was very good (κ = 0.87). The distribution of SLAP lesions was as follows: six type I, 58 type II, one type III, one type IV, 16 type V, one type VI, five type VII, three type VIII, one type IX, one type V and VI, and one type V and VII. Percentages of correct classification of SLAP lesions were variable according to the types, but the overall percentage was noted to be 69.2% for reader 1 and 68.1% for reader 2. The interobserver agreement of classification of SLAP lesions was good (κ = 0.72). CONCLUSION Multidetector CT arthrography shows high accuracy and good interobserver reliability for diagnosis of SLAP lesions in spite of its limitations in specific classification.

Impact of diabetes mellitus on the detection of prostate cancer via contemporary multi (≥12)‐core prostate biopsy

Currently, controversy continues regarding the association between diabetes mellitus (DM) and prostate cancer (PCa). We investigated the impact of DM in PCa detection among men who underwent contemporary multi‐core prostate biopsy.

Effect of bony pelvic dimensions measured by preoperative magnetic resonance imaging on performing robot-assisted laparoscopic prostatectomy

To evaluate the effect of bony pelvic dimensions measured by preoperative magnetic resonance imaging (MRI) on performing robot‐assisted laparoscopic prostatectomy (RALP).

Fluid-fluid levels in ovarian teratomas.

AbstractBackground: We evaluated the imaging features of ovarian teratomas containing fluid–fluid levels on ultrasonography (US). Methods: We retrospectively reviewed US examinations of two groups with 805 masses (370 benign ovarian teratomas and 435 nonteratomatous adnexal masses). Results: In 27 teratomas and eight nonteratomatous adnexal masses, fluid–fluid levels were detected on US. According to the echogenicity of each layer, 27 teratomas were classified as three types: 1, supernatant hypoechoic and dependent hyperechoic layers (n= 16); 2, supernatant hyperechoic and dependent hypoechoic layers (n= 8); and 3, supernatant hypoechoic and dependent hypoechoic layers with bright fluid interface (n= 3). In eight (30%) of 27 teratomas, US showed floating nodules at the interface, five of which had posterior acoustic shadowing. All eight nonteratomatous adnexal masses showed type 1 fluid–fluid levels. Conclusion: The fluid–fluid level seen on US is strongly suggestive but not pathognomonic of dermoids. Fluid–fluid levels with supernatant hyperechoic and dependent hypoechoic layers, supernatant hypoechoic and dependent hypoechoic layers with bright interface, and a floating nodule might pathognomonic findings of benign ovarian teratomas.

Pre-operative prediction of advanced prostatic cancer using clinical decision support systems: accuracy comparison between support vector machine and artificial neural network.

Objective The purpose of the current study was to develop support vector machine (SVM) and artificial neural network (ANN) models for the pre-operative prediction of advanced prostate cancer by using the parameters acquired from transrectal ultrasound (TRUS)-guided prostate biopsies, and to compare the accuracies between the two models. Materials and Methods Five hundred thirty-two consecutive patients who underwent prostate biopsies and prostatectomies for prostate cancer were divided into the training and test groups (n = 300 versus n = 232). From the data in the training group, two clinical decision support systems (CDSSs-[SVM and ANN]) were constructed with input (age, prostate specific antigen level, digital rectal examination, and five biopsy parameters) and output data (the probability for advanced prostate cancer [> pT3a]). From the data of the test group, the accuracy of output data was evaluated. The areas under the receiver operating characteristic (ROC) curve (AUC) were calculated to summarize the overall performances, and a comparison of the ROC curves was performed (p < 0.05). Results The AUC of SVM and ANN is 0.805 and 0.719, respectively (p = 0.020), in the pre-operative prediction of advanced prostate cancer. Conclusion The performance of SVM is superior to ANN in the pre-operative prediction of advanced prostate cancer.

Segmental Enhancement Inversion of Small Renal Oncocytoma: Differences in Prevalence According to Tumor Size

OBJECTIVE The purpose of this study was to retrospectively assess the prevalence of segmental enhancement inversion of small renal oncocytomas according to tumor size. MATERIALS AND METHODS Thirty-three patients (19 men, 14 women; mean age, 61 years; range, 40-74 years) with 33 oncocytomas diagnosed at surgical resection who had undergone contrast-enhanced biphasic CT between January 2000 and December 2011 were included. CT scans were analyzed by two radiologists blinded to the specifics of the pathology report for size, presence of segmental enhancement inversion, enhancement pattern, and homogeneity. Segmental enhancement inversion was present when a renal mass was divided into two differently enhanced segments in the corticomedullary phase (30-40 seconds after contrast injection) with the degree of enhancement reversed in the nephrographic phase (120-180 seconds after contrast injection). The masses were further assessed for fibrous septa, cystic change, hemorrhage, and necrosis. For statistical analysis, the Pearson chi-square test and linear regression were used to evaluate the relation between the prevalence of segmental enhancement inversion and tumor size or pathologic changes. RESULTS The mean diameter of 33 renal oncocytomas was 2.65 cm (range, 0.8-4.8 cm). There was no significant linear trend according to size (p = 0.762), although segmental enhancement inversion was significantly (p = 0.006) more common (10/12) in tumors measuring 1.5-2.9 cm. Pathologic change was present in 14 oncocytomas. There was no significant linear trend according to size (p = 0.068), but 2.5-cm and larger tumors had a significantly higher prevalence (57.9%) (p = 0.036). Segmental enhancement inversion was more common (13/19) in tumors without pathologic change (p = 0.024). CONCLUSION Segmental enhancement inversion was a characteristic finding in our series of small renal oncocytomas and was more common in tumors measuring 1.5-2.9 cm. Pathologic changes such as central scar were more common in oncocytomas larger than 2.5 cm and may be related to the low occurrence of segmental enhancement inversion.

Relationship of Prostate-Specific Antigen and Prostate Volume in Korean Men with Biopsy-Proven Benign Prostatic Hyperplasia

OBJECTIVES To investigate the relationship between prostate-specific antigen (PSA) and prostate volume in a histologically defined subset of Korean men confirmed to have benign prostatic hyperplasia (BPH) only from multicore biopsy of prostate. METHODS A total of 707 Korean men with a PSA level of 10 ng/mL or lower who were shown to have stromoglandular hyperplasia only from transrectal ultrasound (TRUS)-guided multicore biopsy of prostate were included in the study. We analyzed PSA and total prostate volume (TV) measured through TRUS by stratified age cohorts. We used Pearson correlation coefficient (r) and linear regression model to describe the relationship between variables. RESULTS Serum PSA level significantly correlated with TV in all stratified age cohorts, with r ranging from 0.29 to 0.47 (all P <0.001). Meanwhile, the degree of correlation appeared to increase with age. The slope of linear regression showing an association of PSA and TV was 3.68. The PSA increase per unit prostate volume decreased with the advancing cohort of age when we excluded subjects 70 years or older. CONCLUSIONS Although PSA was significantly correlated with TV, the exact nature of the relationship between PSA and TV in Korean men with biopsy-proven BPH may be different from that in other races. Further basic research on the pathophysiology of BPH is needed to explain such a racial difference.

Image-based clinical decision support for transrectal ultrasound in the diagnosis of prostate cancer: comparison of multiple logistic regression, artificial neural network, and support vector machine

PurposeWe developed a multiple logistic regression model, an artificial neural network (ANN), and a support vector machine (SVM) model to predict the outcome of a prostate biopsy, and compared the accuracies of each model.MethodOne thousand and seventy-seven consecutive patients who had undergone transrectal ultrasound (TRUS)-guided prostate biopsy were enrolled in the study. Clinical decision models were constructed from the input data of age, digital rectal examination findings, prostate-specific antigen (PSA), PSA density (PSAD), PSAD in transitional zone, and TRUS findings. The patients were divided into the training and test groups in a randomized fashion. Areas under the receiver operating characteristic (ROC) curve (AUC, Az) were calculated to summarize the overall performance of each decision model for the task of prostate cancer prediction.ResultsThe Az values of the ROC curves for the use of multiple logistic regression analysis, ANN, and the SVM were 0.768, 0.778, and 0.847, respectively. Pairwise comparison of the ROC curves determined that the performance of the SVM was superior to that of the ANN or the multiple logistic regression model.ConclusionImage-based clinical decision support models allow patients to be informed of the actual probability of having a prostate cancer.

Role of transrectal ultrasonography in the prediction of prostate cancer: artificial neural network analysis.

Objective. The purpose of this study was to evaluate the diagnostic performance of an artificial neural network (ANN) model with and without transrectal ultrasonographic (TRUS) data. Methods. Six hundred eighty‐four consecutive patients who had undergone TRUS‐guided prostate biopsy from May 2003 to January 2005 were enrolled. We constructed 2 ANN models. One (ANN_1) incorporated patient age, digital rectal examination findings, prostate‐specific antigen (PSA) level, PSA density, transitional zone volume, and PSA density in the transitional zone as input data, whereas the other (ANN_2) was constructed with the above and TRUS findings as input data. The performances of these 2 ANN models according to PSA levels (group A, 0–4 ng/mL; group B, 4–10 ng/mL; and group C, >10 ng/mL) were evaluated using receiver operating characteristic analysis. Results. Of the 684 patients who underwent prostate biopsy, 214 (31.3%) were confirmed to have prostate cancer; of 137 patients with positive digital rectal examination results, 60 (43.8%) were confirmed to have prostate cancer; and of 131 patients with positive TRUS findings, 93 (71%) were confirmed to have prostate cancer. In groups A, B, and C, the AUCs for ANN_1 were 0.738, 0.753, and 0.774, respectively; the AUCs for ANN_2 were 0.859, 0.797, and 0.894. In all groups, ANN_2 showed better accuracy than ANN_1 (P < .05). Conclusions. According to receiver operating characteristic analysis, ANN with TRUS findings was found to be more accurate than ANN without. We conclude that TRUS findings should be included as an input data component in ANN models used to diagnose prostate cancer.