Heidi Coy

Performance of relative enhancement on multiphasic MRI for the Differentiation of Clear Cell Renal Cell Carcinoma (RCC) from Papillary and Chromophobe RCC subtypes and oncocytoma

OBJECTIVE The objective of our study was to investigate the performance of relative enhancement on multiphasic MRI to differentiate clear cell renal cell carcinoma (RCC) from other RCC subtypes (papillary and chromophobe) and oncocytoma. MATERIALS AND METHODS For this study, we derived a cohort of 34 clear cell RCCs, nine oncocytomas, 12 papillary RCCs, and 10 chromophobe RCCs with a preoperative multiphasic dynamic contrast-enhanced MRI study with up to four phases (i.e., unenhanced, corticomedullary, nephrographic, excretory) from 2005 to 2016. These groups were evaluated for multiphasic enhancement and were compared using Kruskal-Wallis and Mann-Whitney tests. ROC curves were constructed and logistic regression analyses were performed to evaluate the performance of multiphasic enhancement in differentiating clear cell RCCs from the other three groups. RESULTS Clear cell RCCs exhibited significantly greater relative signal intensity compared with uninvolved renal cortex in the corticomedullary phase (mean, 2.9) than oncocytomas (-21.7, p = 0.001), papillary RCCs (-53.0, p < 0.001), and chromophobe RCCs (-21.0, p < 0.001). Relative signal intensity in the corticomedullary phase differentiated clear cell RCCs from oncocytomas with an AUC of 0.90 and with an accuracy of 84% (32/38), sensitivity of 90% (27/30), and specificity of 63% (5/8) after controlling for lesion size, patient age, and patient sex. Relative corticomedullary signal intensity differentiated clear cell RCCs from oncocytomas and other RCC subtypes with an AUC of 0.93 and with an accuracy of 90% (53/59), sensitivity of 90% (27/30), and specificity of 90% (26/29) after controlling for lesion size, patient age, and patient sex. CONCLUSION Multiphasic MRI enhancement may assist in differentiating clear cell RCC from oncocytomas and other RCC subtypes, if validated in prospective studies.

Preliminary results of automated removal of degenerative joint disease in bone scan lesion segmentation

Whole-body bone scintigraphy (or bone scan) is a highly sensitive method for visualizing bone metastases and is the accepted standard imaging modality for detection of metastases and assessment of treatment outcomes. The development of a quantitative biomarker using computer-aided detection on bone scans for treatment response assessment may have a significant impact on the evaluation of novel oncologic drugs directed at bone metastases. One of the challenges to lesion segmentation on bone scans is the non-specificity of the radiotracer, manifesting as high activity related to non-malignant processes like degenerative joint disease, sinuses, kidneys, thyroid and bladder. In this paper, we developed an automated bone scan lesion segmentation method that implements intensity normalization, a two-threshold model, and automated detection and removal of areas consistent with non-malignant processes from the segmentation. The two-threshold model serves to account for outlier bone scans with elevated and diffuse intensity distributions. Parameters to remove degenerative joint disease were trained using a multi-start Nelder-Mead simplex optimization scheme. The segmentation reference standard was constructed manually by a panel of physicians. We compared the performance of the proposed method against a previously published method. The results of a two-fold cross validation show that the overlap ratio improved in 67.0% of scans, with an average improvement of 5.1% points.

Clear Cell Renal Cell Carcinoma: Identifying the Loss of the Y Chromosome on Multiphasic MDCT.

OBJECTIVE The objective of our study was to investigate whether multiphasic MDCT enhancement can help identify clear cell renal cell carcinomas (RCCs) with the loss of the Y chromosome. MATERIALS AND METHODS We derived a cohort of 43 clear cell RCCs in men who underwent preoperative four-phase renal mass MDCT from October 2000 to August 2013. Each lesion was segmented in its entirety on axial images. A computer-assisted detection algorithm selected a 0.5-cm-diameter region of maximal attenuation within each lesion in each phase. A 0.5-cm-diameter ROI was manually placed on uninvolved renal cortex in each phase. The relative attenuation of each lesion was calculated as follows: [(maximal lesion attenuation - cortex attenuation) / cortex attenuation] × 100. Absolute attenuation and relative attenuation in each phase were compared using t tests. RESULTS Both clear cell RCCs with the loss of the Y chromosome and clear cell RCCs without the loss of the Y chromosome exhibited peak enhancement in the corticomedullary phase. However, relative nephrographic attenuation of clear cell RCCs with the loss of Y was significantly less than that of clear cell RCCs without the loss of Y (mean, -8.9 vs 8.4 respectively; p = 0.013). A relative nephrographic attenuation threshold of -1.6 identified the loss of Y with an accuracy of 70% (30/43), sensitivity of 73% (16/22), and specificity of 67% (14/21). CONCLUSION Multiphasic MDCT enhancement may assist in identifying the loss of the Y chromosome in clear cell RCCs; this result should be validated in a large prospective trial.

Clear cell renal cell carcinoma: identifying PTEN expression on multiphasic MDCT

PurposeTo investigate whether multiphasic MDCT enhancement profiles can help to identify PTEN expression in clear cell renal cell carcinomas (ccRCCs). Lack of PTEN expression is associated with worsened overall survival, a more advanced Fuhrman grade, and a greater likelihood of lymph mode metastasis.MethodsWith IRB approval for this retrospective study, we derived a cohort of 103 histologically proven ccRCCs with preoperative 4-phase renal mass MDCT from 2001–2013. Following manual segmentation, a computer-assisted detection algorithm selected a 0.5-cm-diameter region of maximal attenuation within each lesion in each phase; a 0.5-cm-diameter region of interest was manually placed on uninvolved renal cortex in each phase. The relative attenuation of each lesion was calculated as [(Maximal lesion attenuation − cortex attenuation)/cortex attenuation] × 100. Absolute and relative attenuation in each phase were compared using t tests. The performance of multiphasic enhancement in identifying PTEN expression was assessed with logistic regression analysis.ResultsPTEN-positive and PTEN-negative ccRCCs both exhibited peak enhancement in the corticomedullary phase. Relative corticomedullary phase attenuation was significantly greater for PTEN-negative ccRCCs in comparison to PTEN-positive ccRCCs (33.7 vs. 9.5, p = 0.03). After controlling for lesion stage and size, relative corticomedullary phase attenuation had an accuracy of 84% (86/103), specificity of 100% (84/84), sensitivity of 11% (2/19), positive predictive value of 100% (2/2), and negative predictive value of 83% (84/101) in identifying PTEN expression.ConclusionRelative corticomedullary phase attenuation may help to identify PTEN expression in ccRCCs, if validated prospectively.

MP22-07 CORRELATION OF CAD PEAK LESION ENHANCEMENT WITH QUANTITATIVE TUMOR ANGIOGENESIS TO NON-INVASIVELY ASSESS FURHMAN GRADES I-IV IN PATIENTS WITH CLEAR CELL RENAL CELL CARCINOMA

INTRODUCTION AND OBJECTIVES: To assess if Computer Aided Detection (CAD) of peak lesion attenuation discriminates among Fuhrman Grades I-IV and correlates with an increase in tumor angiogenesis in clear cell RCC (ccRCC) on four-phase MDCT. METHODS: We reviewed a cohort of patients with ccRCC and preoperative multiphasic multidetector CT imaged with a 4-phase renal mass protocol (unenhanced, corticomedullary (C), nephrographic (N), and excretory (E)). A whole lesion 3D contour was obtained in all phases with proprietary software. The CAD algorithm determined a 0.5cm diameter region of peak enhancement 300HU within the 3D lesion contour. For assessment of quantitative angiogenesis, immunohistochemical staining for CD34 to determine microvessel density (MVD) was performed. T-tests were used to compare peak multiphasic enhancement and microvessel density among Fuhrman grades I-IV. P values less than 0.05 were considered to be significant. RESULTS: 107 patients (71(64%) men and 40(35%) women) with 111 unique ccRCC lesions (16 (14%) Fuhrman grade I, 64 (58%) Fuhrman grade II, 23 (21%) Fuhrman Grade III, 8 (7%) Fuhrman grade IV) were analyzed. In the C phase, CAD peak lesion enhancement discriminated grade I from II (150 HU vs. 185 HU, p1⁄40.006), I from III (150 HU vs. 178 HU, p1⁄40.054), I from IV (150 HU vs 229HU, p<0.001). This directly correlated with an increase in quantitative angiogenesis (MVD): I from II (2134 mm2 vs. 4710 mm2, p1⁄40.004), I from III (2134 mm2 vs. 5162 mm, p1⁄40.001), I from IV (2134 mm2 vs 6076 mm2, p1⁄40.057). CONCLUSIONS: CAD peak lesion enhancement discriminates Fuhrman grades 1-IV on multiphasic CT and correlates with an increase in tumor angiogenesis. This may be helpful to triage patients to active surveillance, interventional therapy or, if validated, may be useful to monitor results with anti-angiogenic therapy.

Efficacy of MR-guided focused ultrasound ablation for localized adenomyosis in comparison to leiomyoma

Symptomatic localized adenomyosis is generally treated conservatively, or with more radical treatments such as hysterectomy. An effective non-invasive therapy is needed, especially for those who wish to preserve their fertility. MR-guided Focused Ultrasound ablation (MRgFUS) has been shown as an effective treatment for symptomatic uterine leiomyomas with a large non-perfused volume (NPV) immediately after treatment. Our specific aim was to compare the change in NPV in subjects with localized adenomyomas treated with MRgFUS, with the change in NPV in subjects treated with MRgFUS for symptomatic uterine leiomyomas to determine if similar results were achieved in the localized adenomyoma cohort.