Postsurgical Findings Research Articles

An instantly applicable machine learning model for extraprostatic extension prediction in prostate cancer: A post-hoc analysis of the RAPID 68Ga-PSMA PET/MRI trial

Radical prostatectomy (RP) is a common first-line treatment for patients with localized prostate cancer (PCa), with nerve-sparing techniques recommended to minimize adverse effects on quality of life. Accurate pre-operative detection of extraprostatic extension (EPE) remains difficult, often resulting in suboptimal treatment choices. Machine learning (ML) has the potential to improve pre-operative EPE detection through the integration of multimodal data, but its clinical adoption is hindered by implementation complexities and explainability issues. This study conducted a post-hoc analysis of a prospective clinical trial (NCT02659527) involving patients who underwent [68Ga]Ga-PSMA-11 PET/MRI from 2014 to 2019. Only the clinically used parameters were collected, including PET-derived features, blood-based markers, histology-derived parameters, and patient demographics. ML models were developed using either only non-invasive features or a combination of non-invasive and invasive features for EPE detection and were compared to conventional PET image readings. Among the 77 patients included in the study, 44 (57%) had EPE based on post-surgical findings. The ML models outperformed traditional PET image readings in diagnostic accuracy, with the explainable boosting machine (EBM) model achieving an AUC of 0.88. The ML model incorporating invasive features showed superior predictive ability for EPE compared to visual clinical assessments (AUC 0.88 vs. 0.71, p 0.02), while the difference between the ML model with non-invasive features and clinical assessments was not significant (AUC 0.83 vs. 0.71, p 0.34). Explainable ML models utilizing routinely acquired clinical data can greatly enhance the pre-operative detection of EPE in PCa patients, potentially leading to more accurate clinical staging, better treatment decisions, and improved patient outcomes. Please click on the 'PDF' for the full abstract!

Accuracy of endobronchial ultrasound-guided transbronchial needle aspiration for staging of non-small cell lung cancer.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is routinely performed to confirm a lung cancer diagnosis and/or to clinically stage disease. EBUS-TBNA findings may be used to determine whether patients can be offered potentially curative surgery. In this study, we evaluated the reporting in our service of EBUS-TBNA cytology for early-stage (operable) non-small cell lung cancer (NSCLC), focusing on diagnostic accuracy and analyzing cases with discordant cytologic and post-surgical histopathologic conclusions. Cytology slides and cytopathology reports of 120 NSCLC patients who had undergone EBUS-TBNA and lobectomy in our hospital system between 2015 and 2021 were retrospectively reviewed. Of 290 lymph nodes (110 cases) able to be reviewed, interpretation of 48 lymph nodes was discordant with the original cytopathology report. This included 31 lymph nodes originally reported as adequate, which were found to be non-diagnostic on review. The diagnostic accuracy (benign/malignant) of lymph nodes that were sampled at EBUS-TBNA and excised at surgery was 89%. Specific examination of cases where EBUS-TBNA cytology did not reflect post-surgical findings illustrated important features and limitations of the procedure. These included potential misclassification of lymph node stations, the presence of multiple, variably involved nodes at lymph node stations, and the failure to detect small volume disease. Continuous evaluation of EBUS-TBNA performance identifies technical limitations and areas of improvement for cytopathology reporting. This is increasingly important in an era where lung cancer screening is expected to increase diagnosis of early-stage disease and with the advent of novel treatments, including non-surgical management options.

Laparoscopic hiatal hernia repair for treating patients with massive hiatal hernia and iron-deficiency anaemia

BackgroundMassive hiatal hernias may result in extraoesophageal symptoms, including iron-deficiency anaemia. However, the role played by hiatal hernias in iron-deficiency anaemia is not clearly understood. We examined the prevalence of anaemia in patients with massive hiatal hernias and the frequency of anaemia resolution after laparoscopic hiatal hernia repair at long term follow-up.MethodsPatients who underwent laparoscopic hiatal hernia repair from June 2008 to June 2019 were enrolled in this study. We collected the patients’ demographic and clinical data from their medical records, and compared the pre-surgical and post-surgical findings (at 1 week and 3 months post-surgery). All patients with adequate documentation underwent post-surgical follow-up to evaluate improvements in clinical symptoms and signs.ResultsA total of 126 patients with massive hiatal hernias underwent laparoscopic hiatal hernia repair. Of these, 35 (27.8%) had iron-deficiency anaemia. Anaemia was resolution in all the patients and they had significantly reduced GERD-Q scores at 3 months postoperatively (P<0.01) .The mean follow-up period was 60 months. Iron-deficiency anaemia resolution after hiatal hernia repair was achieved in 93.9% of the patients.ConclusionAnaemia is common in patients with massive hiatal hernias, and most of our patients were symptomatic because of their anaemia. Moreover, in patients with massive hiatal hernias, iron-deficiency anaemia resolution is likely after laparoscopic hiatal hernia repair.

In bag IOL implantation with Cionni ring: A case report

The supertemporal subluxation of the lens due to zonular weakness is one of the hallmarks of ocular signs with Marfan's syndrome. Cionni capsular tension ring (CTR) implantation can help to overcome this issue and correct the capsular bag decentration. We describe the visual outcome, intra and post-surgical findings of phacoemulsification with Cionni capsular tension ring and PCIOL implantation in a case of an 18-year-old-boy presented with the features of a typical Marfan’s syndrome.

Do not get stumped: multimodality imaging findings of early and late post-cholecystectomy complications

Cholecystectomy is the most performed intra-abdominal surgical procedure in the US, with 1.2 million performed annually, and is predominantly performed laparoscopically. Although largely safe, laparoscopic cholecystectomy results in higher rates of abdominal symptoms consisting of abdominal pain and dyspepsia, which may persist or recur, collectively known as post-cholecystectomy syndrome. This article aims to (1) provide an overview of post-cholecystectomy syndrome with an emphasis on biliary complications and emergent imaging findings, (2) illustrate the spectrum of imaging findings of early and late post-cholecystectomy complications, (3) enumerate the role of various imaging modalities in evaluating post-cholecystectomy complications and address the role of selective trans-catheter coil embolization in managing bile leaks, and (4) discuss pearls and pitfalls in imaging following cholecystectomy. While common first-line imaging modalities for post-cholecystectomy complications include CT and sonography, ERCP and MRCP can delineate the biliary tree with greater detail. Scintigraphy has a higher sensitivity and specificity than CT or sonography for diagnosing bile leak and may preclude the need for ERCP. Post-operative complications include biliary duct injury or leak, biliary obstruction, remnant gallbladder/cystic duct stones and inflammation, biliary dyskinesia, papillary stenosis, and vascular injury. Subtle cases resulting in lethal outcomes, such as hemorrhage from the gallbladder bed without major vessel injury, have also been described. Cases presented will include biliary complications such as post-cholecystectomy stump cholecystitis, nonbiliary complications such as subcapsular hematoma, and normal post-surgical findings such as oxidized regenerated cellulose. Post-operative biliary complications can cause significant morbidity and mortality, and thus familiarity with the expected post-surgical appearance of the gallbladder fossa and biliary tract, as well as understanding the spectrum of complications and associated multimodality imaging findings, are essential for emergency radiologists and those practicing in the acute care setting to direct appropriate patient management. Furthermore, many of the postoperative complications can be managed by noninvasive percutaneous interventional procedures, from drain placement to cystic artery and cystic duct stump embolization.

Abstract 2736: Forecasting treatment response to neoadjuvant therapy in triple-negative breast cancer via an image-guided digital twin

Abstract Introduction: Patients with locally advanced, triple-negative breast cancer (TNBC) typically receive neoadjuvant therapy (NAT) to downstage the tumor and to improve the outcome of subsequent breast conservation surgery. There are currently no methods to accurately predict how a TNBC patient will respond to NAT before surgery. In this work, we applied a digital twin framework to address this unmet clinical need, by integrating quantitative magnetic resonance imaging (MRI) data with mechanism-based mathematical modeling. Methods: Multiparametric MRI was acquired in patients (N = 50) before, after 2 and 4 cycles of Adriamycin/Cyclophosphamide (A/C), and again after 12 cycles of Paclitaxel as part of the ARTEMIS (NCT02276433) trial. Within each imaging session, dynamic contrast-enhanced (DCE) MRI, diffusion-weighted imaging (DWI), and a pre-contrast T1-map were acquired. The images were processed by a pipeline consisting of motion correction, multiparametric image alignment, inter-visit image registration to align the tumor and surrounding breast tissue, tissue segmentation, and estimation of tumor cellularity from DWI. A mechanism-based mathematical model, a reaction-diffusion equation, is used to characterize the mobility of tumor cells via diffusion damped by mechanical tissue properties, tumor proliferation via logistic growth, and treatment-induced cell death via the delivery and decay of therapies. For each patient, pre-treatment images were used for model initialization. The model calibration and prediction were implemented with two strategies: 1) using images acquired during the A/C for calibration and predicting up to the end of A/C, and 2) using images acquired during and after the A/C for calibration and predicting up to the end of NAT. For strategy 1), we evaluated the model by comparing its predicted tumor volume and total tumor cellularity to the imaging measurements at the end of A/C. For strategy 2), we evaluated the model by comparing its predicted final response to the post-surgical pathological findings. Results: For strategy 1), our framework predicted the change of tumor volume and total tumor cellularity with Pearson correlation coefficients of 0.91 and 0.89, respectively. Regarding strategy 2), our framework achieved an area under the receiver operator characteristic curve of 0.88 for distinguishing pCR from non-pCR. As a comparison, imaging measurement of tumor volume at the end of A/C achieved an AUC of 0.79. Conclusion: Our approach successfully captures the patient-specific dynamics of TNBC response to NAT and provides an improved prediction of final response, which demonstrates the potential of a digital twin framework to be a powerful tool for predicting response to NAT. Once validated, the method will provide a unique opportunity for optimizing treatment plans on a patient-specific basis. Citation Format: Chengyue Wu, Angela M. Jarrett, Zijian Zhou, Nabil Elshafeey, Beatriz E. Adrada, Rosalind P. Candelaria, Rania Mohamed, Medine Boge, Lei Huo, Jason White, Debu Tripathy, Vicente Valero, Jennifer Litton, Clinton Yam, Jong Bum Son, Jingfei Ma, Gaiane M. Rauch, Thomas E. Yankeelov. Forecasting treatment response to neoadjuvant therapy in triple-negative breast cancer via an image-guided digital twin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2736.

Unusual Giant Calculus of Left Submandibular Duct

Sialolithiasis account for the most common disease of salivary glands. The majority of salivary gland calculi involve the submandibular duct and rarely in its parenchyma. This is common benign disease may cause the acute or chronic sialadenitis. Sialolith can be single, multiple, unilateral or bilateral. Patient can presents with history of swelling and pain. Giant sialolithiasis is not a common condition mainly occur in submandibular duct. Here we discuss the unusual giant submandibular duct calculus in adult male patient, its Computed Tomography (CT) scan appearance and post-surgical findings.

Overview of Oncoplastic Breast Surgery Techniques for the Treatment of Breast Cancer with Review of Normal and Abnormal Postsurgical Imaging Findings

Overview of Oncoplastic Breast Surgery Techniques for the Treatment of Breast Cancer with Review of Normal and Abnormal Postsurgical Imaging Findings

Malignancy risk of indeterminate mammographic calcification in symptomatic breast clinics

BackgroundTo explore the potential risk factors predicting malignancy in patients with indeterminate incidental mammographic microcalcification and to evaluate the short-term risk of developing malignancy.MethodsBetween January 2011 and December 2015, one...

Malignancy risk of indeterminate mammographic calcification in symptomatic breast clinics.

To explore the potential risk factors predicting malignancy in patients with indeterminate incidental mammographic microcalcification and to evaluate the short-term risk of developing malignancy. Between January 2011 and December 2015, one hundred and fifty (150) consecutive patients with indeterminate mammographic microcalcifications who had undergone stereotactic biopsy were evaluated. Clinical and mammographic features were recorded and compared with histopathological biopsy results. In patients with malignancy, postsurgical findings and surgical upgrade, if any, were recorded. Linear regression analysis (SPSS V.25) was used to evaluate significant variables predicting malignancy. OR with 95% CIs was calculated for all variables. All patients were followed up for a maximum of 10 years. The mean age of the patients was 52 years (range 33-79 years). There were a total of 55 (37%) malignant results in this study cohort. Age was an independent predictor of breast malignancy with an OR (95% CI) of 1.10 (1.03 to 1.16). Mammographic microcalcification size, pleomorphic morphology, multiple clusters and linear/segmental distribution were significantly associated with malignancy with OR (CI) of 1.03 (1.002 to 1.06), 6.06 (2.24 to 16.66), 6.35 (1.44 to 27.90) and 4.66 (1.07 to 20.19). The regional distribution of microcalcification had an OR of 3.09 (0.92 to 10.3), but this was not statistically significant. Patients with previous breast biopsies had a lower risk of breast malignancy than patients with no prior biopsy (p=0.034). Multiple clusters, linear/segmental distribution, pleomorphic morphology, size of mammographic microcalcifications and increasing age were independent predictors of malignancy. Having a previous breast biopsy did not increase malignancy risk.

Correlation between Pre- and Post-Surgical Findings for Long-Term Neurocognitive and Behaviour Development Due to Posterior Fossa Pilocytic Astrocytomas: The Trend after 10 Years.

Objective: The objective of the present study was to selectively evaluate the long-term impact of posterior fossa pilocytic astrocytomas, which are known to be among the most benign forms of paediatric brain tumours on neurocognitive and behavioural functions. Methods: Children that were operated on for a posterior fossa pilocytic astrocytoma in the Pediatric Neurosurgery Department of the Catholic University Medical School were selected according to the following criteria: (a) age > 5 years (in order to have a complete set of neurocognitive evaluations data), (b) ability to perform a complete set of tests before and after surgery, and (c) children that had a regular follow-up up to 10 years from the surgical treatment. Results: Forty-three percent of the children selected for the present study showed a borderline IQ before surgery, which is a result corresponding to those previously reported in the literature for children affected by posterior fossa pilocytic astrocytomas; praxis and visual perception were the selective functions that were more frequently affected. Language performance tests scores were below average in 40% of the cases but tended to improve in terms of expressive and receptive skills even at the 1-year follow-up; the improvements became significant at the 5-year and 10-year follow-ups. Conclusions: Recognising and measuring the short- and long-term effects of cerebellar tumours in children and their treatment are the first step towards improving their clinical course and quality of life. Early interventions should be offered to all of them, with specific attention bestowed on visual-spatial stimulation, speech and occupational therapies in order to act on praxic and visuo-perceptive skills, as well as on emotion and behaviour tracts of the neurocognitive profile, which more commonly tend to persist in the long term.

Pearls and Pitfalls in Postsurgical Imaging of the Chest

A variety of surgical procedures are utilized to treat a spectrum of cardiopulmonary diseases. In the imaging of patients in the post-operative period, it is important to have an understanding of surgical techniques including invasive and minimally invasive procedures and the expected postsurgical findings. Knowledge of certain patient risk factors, various complications associated with specific surgical procedures, and a keen attention to detail are essential to avoid misinterpretation and delay diagnosis. Prompt detection of potential complications allows timely intervention, thereby, optimizing patient outcomes in the post-operative period.

Computed-Tomography-Structured Reporting in Middle Ear Opacification: Surgical Results and Clinical Considerations From a Large Retrospective Analysis.

Purpose: The aim of the study is to compare the accuracy of unstructured preoperative Computed Tomography (CT) reports from non-tertiary diagnostic centers with intraoperative findings in a large cohort of patients with Chronic Otitis Media (COM) undergone surgery.Methods: From 2012 to 2019, a total number of 301 patients were considered for our purposes. All patients with clinical evidence of COM had preoperative non-contrast high resolution CT scan of the temporal bone in non-tertiary diagnostic centers, performed within 3 months before surgery.Results: The accuracy of CT reports was analyzed in terms of nature, anatomical site, disease extension, bony erosion, vascular structures abnormalities relevant to surgical planning, and Eustachian tube patency. Compared to post-surgical findings, CT reporting critical analysis revealed a tendency to overestimation of bony erosion, coupled to underestimated description of facial canal/lateral semi-circular canal, vascular structures, and Eustachian tube.Conclusion: Discrepancies between CT reports and surgical findings in middle ear opacification can be at least in part due to limited expertise of general radiologists in ENT neuroimaging. To limit this lack of information and the limited accuracy of middle ear structures depiction, here we propose a structured checklist to adopt in the case of a temporal bone CT scan for COM, in order to optimize the communication with surgeons and provide all the crucial information for an accurate surgical planning.

Palliative ventriculoperitoneal shunting in dogs with obstructive hydrocephalus caused by tumors affecting the third ventricle.

BackgroundHypertensive or obstructive hydrocephalus is a common complication in dogs with tumors affecting the third ventricle for which few therapeutic options are available.ObjectivesTo describe signalment, neurological status, and pre‐ and postsurgical findings, complications and survival time in 4 dogs with obstructive hydrocephalus caused by third ventricle tumors that were palliatively treated using ventriculoperitoneal shunting (VPS).AnimalsFour client‐owned dogs with obstructive hydrocephalus caused by tumors affecting the third ventricle.MethodsMedical records were reviewed for dogs diagnosed with third ventricular tumors. Inclusion criteria were complete medical record, advanced diagnostic imaging for review, and VPS as sole surgical treatment.ResultsAt the time of diagnosis, all patients displayed acute onset and rapidly progressive diffuse intracranial clinical signs. On advanced imaging, all dogs had a homogeneously enhancing mass occupying or collapsing the third ventricle as well as obstructive hydrocephalus. All of the dogs underwent VPS of the most dilated lateral ventricle. In 2 of the patients, intracranial hypertension followed by normotension after VPS placement was confirmed intraoperatively by means of direct intracranial pressure monitoring. Excellent clinical improvement was observed in all dogs immediately after surgery. Three patients required a second VPS in the contralateral lateral ventricle 3, 7 and 11 months after the first surgery, all of them with renewed improvement in clinical signs.Conclusion and Clinical ImportanceVentriculoperitoneal shunting is a rapid and effective treatment for patients with obstructive (hypertensive) hydrocephalus caused by tumors located within the third ventricle.

Perianal fistula mapping at 3 T: volumetric versus conventional MRI sequences

To evaluate volumetric contrast-enhanced three-dimensional T1-weighted (CE 3D T1) turbo spin-echo (TSE) with variable flip angle (SPACE), CE 3D T1 volumetric interpolated breath-hold examination (VIBE) sequences with conventional CE-two-dimensional (2D)-T1 and 2D-T2-weighted imaging (WI) sequences in assessing perianal fistulas. Twenty-three patients with perianal fistula were included in this prospective study and underwent pelvic magnetic resonance imaging (MRI) at 3 T including fat-supressed CE 3D T1 SPACE, CE 3D T1 VIBE, axial and coronal 2D-T1WI together with 2D-T2WI sequences in the axial and coronal planes. Acquisition times were recorded. Performance of each sequence was evaluated in terms of image quality, presence of artefacts, lesion conspicuity, fistula type, presence of abscess, visibility of internal orifice, and number of internal orifices. Results were compared with post-surgical findings defined as the reference standard. Both CE 3D T1 VIBE and CE 3D T1 SPACE were the best sequences to determine fistula type and in terms of image quality, artefacts, and determining locations of internal orifices. The number of internal orifices was detected correctly in 23 (100%) patients for CE 3D T1 SPACE and CE 3D T1 VIBE sequences, in 17 (73.9%) patients on CE-T1WI, and in seven (30.4%) patients on 2D-T2WI. Lesion conspicuity was higher for CE 3D T1 SPACE and CE 3D T1 VIBE sequences compared to the 2D sequences (p<0.05). The overall acquisition time for each 3D sequence was shorter compared to the 2D sequences combined. CE 3D T1 SPACE and CE 3D T1 VIBE sequences may outperform conventional 2D sequences in the evaluation of perianal fistulas in terms of visibility and number of internal orifices with a shorter scanning time.

1050 Normal imaging findings after aortic valve implantation on 18f-fluorodeoxyglucose positron emission tomography with computed tomography and computed tomography angiography

Abstract Purpose Although 18F-Fluorodeoxyglucose (18F-FDG) Positron Emission Tomography (PET) with computed tomography (CT) and cardiac computed tomography angiography (CTA) are essential tools in diagnosing prosthetic heart valve (PHV) endocarditis, the normal imaging findings in the first year after PHV implantation on 18F-FDG-PET/CT and CTA have not been studied prospectively. We prospectively assessed the perivalvular FDG uptake at different time points after aortic PHV implantation and assessed the normal imaging findings on CTA. Materials and methods Patients who had undergone uncomplicated aortic PHV implantation were included and underwent 18F-FDG PET/CT and CTA at 5(±1) weeks (group 1), 12(±2) weeks (group 2) or 52(±8) weeks (group 3) after implantation. After a preparatory diet to suppress normal myocardial glucose uptake, FDG uptake in the myocardium as well as around the PHV was scored using the Qualification Visual Score for Hypermetabolism (QVSH) as "none" (&amp;lt; mediastinum), "low" (&amp;gt; mediastinum but &amp;lt; liver), "intermediate" (&amp;gt; liver), or "high" (intense uptake) and quantitative analysis was performed with maximum Standardized Uptake Value (SUVmax) and target to background ratio (SUVratio) on standardized European Association of Nuclear Medicine Research Ltd. (EARL) reconstructions by an experienced nuclear medicine physician. CTA was analysed for image quality, artefacts and stranding of the peri-aortic fat by a cardiac radiologist. Results In total 37 patients (group 1: n = 12, group 2: n = 12, group 3: n = 13) (age 66 ± 8 years) were included. Myocardial FDG uptake was intermediate or less in 29/37 scans (78%). QVSH around the PHV was 8/12(67%) low and 4/12(33%) intermediate in group 1, 7/12(58%) low and 5/12(42%) intermediate in group 2 and 8/13(62%) low and 5/13(38%) intermediate in group 3 (p = 0.91). No scan was scored as "none" or "high". EARL SUVmax was 3.48 ± 0.57, 3.50 ± 0.59 and 3.34 ± 0.55 (mean ± SD, p = 0.77) and EARL SUVratio was 2.00 ± 0.29, 1.96 ± 0.41 and 1.71 ± 0.26 (mean ± SD, p = 0.07) for groups 1, 2 and 3, respectively. One patient in group 3 refused to undergo the additional CTA and one CTA in group 3 could not be analysed for image quality and artefacts due to techniqual difficulties. Overall CTA image quality was "good" or "excellent" with an artefact score of "virtually none" or "mild" in most cases (n = 33, 94%). Stranding of peri-aortic fat was seen in 27/35 (77%) of these patients (group 1: n = 11; group 2: n = 9; group 3: n = 7) with no signs of FDG uptake on PET/CT scan. Conclusion Baseline FDG uptake around aortic PHV at 5, 12 and 52 weeks after implantation is similar and mild in the majority of cases with an overall mean SUVmax and SUVratio of 3.44 ± 0.56 and 1.89 ± 0.34 respectively. CTA revealed baseline post-surgical findings in the first year after PHV implantation.

Mimics of Complications in the Postsurgical Aorta at CT.

Various surgical techniques of the aorta result in expected imaging appearances on CT images that resemble complications such as pseudoaneurysm, perigraft abscess, and dissection. Awareness of these techniques, understanding the clinical situation in which they are performed, and familiarity with the typical appearances and locations of these mimics are essential for accurate interpretation. CT imaging techniques such as electrocardiographic gating and inclusion of a precontrast series can help distinguish an expected postsurgical finding from a complication. Information in the medical record, particularly the operative note, can clarify challenging cases with unusual imaging features. This review article provides examples of expected postsurgical findings at CT mimicking complications. © RSNA, 2019.

Abnormal aortic flow profiles persist after aortic valve replacement in the majority of patients with aortic valve disease: how model-based personalized therapy planning could improve results. A pilot study approach.

Complex blood flow profiles in the aorta are known to contribute to vessel dilatation. We studied flow profiles in the aorta in patients with aortic valve disease before and after surgical aortic valve replacement (AVR). Thirty-four patients with aortic valve disease underwent 4-dimensional velocity-encoded magnetic resonance imaging before and after AVR (biological valve = 27, mechanical valve = 7). Seven healthy volunteers served as controls. Eccentricity (ES) and complex flow scores (CFS) were determined from the degree of helicity, vorticity and eccentricity of flow profiles in the aorta. Model-based therapy planning was used in 4 cases to improve in silico postoperative flow profiles by personalized adjustment of size, rotation and angulation of the valve as well as aorta diameter. Patients with aortic valve disease showed more complex flow than controls [median ES 2.5 (interquartile range (IQR) 2.3-2.7) vs 1.0 (IQR 1.0-1.0), P < 0.001, median CFS 4.7 (IQR 4.3-4.8) vs 1.0 (IQR 1.0-2.0), P < 0.001]. After surgery, flow complexity in the total patient cohort was reduced, but remained significantly higher compared to controls [median ES 2.3 (IQR 1.9-2.3) vs 1.0 (IQR 1.0-1.0), P < 0.001, median CFS 3.8 (IQR 3.0-4.3) vs 1.0 (IQR 1.0-2.0), P < 0.001]. In patients after mechanical AVR, flow complexity fell substantially and showed no difference from controls [median ES 1.0 (IQR 1.0-2.3) vs 1.0 (IQR 1.0-1.0), P = 0.46, median CFS 1.0 (IQR 1.0-3.3) vs 1.0 (IQR 1.0-2.0), P = 0.71]. In all 4 selected cases (biological, n = 2; mechanical, n = 2), model-based therapy planning reduced in silico complexity of flow profiles compared to the existing post-surgical findings [median ES 1.7 (IQR 1.4-1.7) vs 2.3 (IQR 2.3-2.3); CFS 1.7 (IQR 1.4-2.5) vs 3.8 (IQR 3.3-4.3)]. Abnormal flow profiles in the aorta more frequently persist after surgical AVR. Model-based therapy planning might have the potential to optimize treatment for best possible individual outcome. clinicaltrials.gov NCT03172338, 1 June 2017, retrospectively registered; NCT02591940, 30 October 2015, retrospectively registered.

Abstract 2636: Combined MRI and molecular signatures of prostate cancer: Association with biochemical recurrence

Abstract Purpose: To assess the correlation of histologic and prostate cancer associated gene oncoprotein expression and imaging features in MRI-detected lesions of prostate cancer patients with biochemical recurrence (BCR) after definitive treatment. Methods: Patients underwent multiparametric MRI (mpMRI) at 3T at a single institution prior to TRUS/MRI fusion-guided biopsy of MRI-defined index lesions and prior to definitive therapy (radical prostatectomy), for which clinical follow-up was available. All mpMRI lesions were prospectively scored low, moderate, moderate-high, or high for suspicion of harboring clinically significant cancer, as determined by positivity on individual MRI sequences and indication of extraprostatic extension (EPE) on imaging. The expression of prostate cancer drivers (ERG, PTEN, AR and p53) and PSA were examined on targeted-biopsy specimens by immunohistochemistry (IHC). All histological assessments were completed blinded to imaging findings and treatment outcomes. Cox proportional hazard regression was used to evaluate associations between imaging, molecular, and surgical characteristics with interval to BCR. Results: In a preliminary cohort of 56 patients, 29 patients met clinical criteria for BCR (median interval 12.46 months, range 1-55 months) and 27 patients remain recurrence-free (median follow-up 30.75 months, range 1-72+ months). Median interval between mpMRI and targeted biopsy was 29 days (range 12-167 days) and radical prostatectomy was 4.13 months (range 1.3-8.0 months). Pre-operative serum PSA was the strongest correlate with time to BCR (HR: 1.63, 95%-CI: 12.-2.1, p&amp;lt;0.0001). The p53 staining intensity 3+ in &amp;gt;1% of cells or 2+ in &amp;gt;10% of cells was associated with poor BCR interval (HR: 3.35, 95%-CI: 1.5-7.2, p=0.002), remaining so in multivariate model with pre-operative MRI, PSA, and post-surgical findings on pathology. p53 positivity was observed more frequently in Gleason≥4+3, for both biopsy (fisher's exact p=0.006) and final pathology grading (fisher's exact p=0.01). Moderate/high to high index MRI suspicion was found to correlate with EPE at surgery (fisher's exact p=0.03) and showed modest correlation to time-to-BCR in univariate analysis (HR: 2.11, 95%-CI: 0.99-4.5, p= 0.052) and remained so in multivariate analysis. PTEN loss was observed in 8 patients (14%). PSA+ expression by IHC was observed in 49/56 patients, with remaining 7 patients showing variable/heterogeneous (PSA+/-) expression. Conclusions: MRI impression and p53 status from MRI index lesion were independent predictors of time to biochemical recurrence, along with pre-operative PSA levels. These results are part of an ongoing study to identify histo-radiological features of aggressive prostate cancers. Citation Format: Stephanie A. Harmon, William Gesztes, Denise Young, Sherif Mehralivand, Brad J. Wood, Peter A. Pinto, Gyorgy Petrovics, Albert Dobi, Inger L. Rosner, Baris Turkbey, Shiv Srivastava, Peter L. Choyke, Isabelle A. Sesterhenn. Combined MRI and molecular signatures of prostate cancer: Association with biochemical recurrence [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2636.

Model-based Iterative Reconstruction in Low-radiation-dose Computed Tomography Colonography: Preoperative Assessment in Patients with Colorectal Cancer

To assess the effect of model-based iterative reconstruction (MBIR) on image quality and diagnostic performance of low-radiation-dose computed tomography colonography (CTC) in the preoperative assessment of colorectal cancer. This study included 30 patients with colorectal cancer referred for surgical treatment. All patients underwent CTC with a standard dose (SD) protocol in the supine position and a low-dose (LD; radiation dose reduction of approximately 85%) protocol in the prone position. The SD protocol images were post-processed using filtered back projection (FBP), whereas the LD protocol images were post-processed using FBP and MBIR. Objective and subjective image quality parameters were compared among the three different methods. Preoperative evaluations, including site, length, and tumor and node staging were performed, and the findings were compared to the postsurgical findings. The mean image noise of SD-FBP, LD-FBP, and LD-MBIR images was 17.3 ± 3.2, 40.5 ± 10.9, and 11.2 ± 2.0 Hounsfield units, respectively. There were significant differences for all comparison combinations among the three methods (P < .01). For image noise, the mean visual scores were significantly higher for SD-FBP and LD-MBIR than for LD-FBP, and the scores for SD-FBP and LD-MBIR were equivalent (3.9 ± 0.3 [SD-FBP], 2.0 ± 0.5 [LD-FBP], and 3.7 ± 0.3 [LD-MBIR]). Preoperative information was more accurate under SD-FBP and LD-MBIR than under LD-FBP, and the information was comparable between SD-FBP and LD-MBIR. MBIR can yield significantly improved image quality on low-radiation-dose CTC and provide preoperative information equivalent to that of standard-radiation-dose protocol.