PET/CT-Based Absorbed Dose Maps in 90Y Selective Internal Radiation Therapy Correlate with Spatial Changes in Liver Function Derived from Dynamic MRI.

Functional liver parenchyma can be damaged from treatment of liver malignancies with 90Y selective internal radiation therapy (SIRT). Evaluating functional parenchymal changes and developing an absorbed dose (AD)-toxicity model can assist the clinical management of patients receiving SIRT. We aimed to determine whether there is a correlation between 90Y PET AD voxel maps and spatial changes in the nontumoral liver (NTL) function derived from dynamic gadoxetic acid-enhanced MRI before and after SIRT. Methods: Dynamic gadoxetic acid-enhanced MRI scans were acquired before and after treatment for 11 patients undergoing 90Y SIRT. Gadoxetic acid uptake rate (k1) maps that directly quantify spatial liver parenchymal function were generated from MRI data. Voxel-based AD maps, derived from the 90Y PET/CT scans, were binned according to AD. Pre- and post-SIRT k1 maps were coregistered to the AD map. Absolute and percentage k1 loss in each bin was calculated as a measure of loss of liver function, and Spearman correlation coefficients between k1 loss and AD were evaluated for each patient. Average k1 loss over the patients was fit to a 3-parameter logistic function based on AD. Patients were further stratified into subgroups based on lesion type, baseline albumin-bilirubin scores and alanine transaminase levels, dose-volume effect, and number of SIRT treatments. Results: Significant positive correlations (ρ = 0.53-0.99, P < 0.001) between both absolute and percentage k1 loss and AD were observed in most patients (8/11). The average k1 loss over 9 patients also exhibited a significant strong correlation with AD (ρ ≥ 0.92, P < 0.001). The average percentage k1 loss of patients across AD bins was 28%, with a logistic function model demonstrating about a 25% k1 loss at about 100 Gy. Analysis between patient subgroups demonstrated that k1 loss was greater among patients with hepatocellular carcinoma, higher alanine transaminase levels, larger fractional volumes of NTL receiving an AD of 70 Gy or more, and sequential SIRT treatments. Conclusion: Novel application of multimodality imaging demonstrated a correlation between 90Y SIRT AD and spatial functional liver parenchymal degradation, indicating that a higher AD is associated with a larger loss of local hepatocyte function. With the developed response models, PET-derived AD maps can potentially be used prospectively to identify localized damage in liver and to enhance treatment strategies.

What can go wrong when doing right? A pictorial review of iatrogenic genitourinary complications.

A growing number of treatments for genitourinary diseases can result in various iatrogenic complications. Multimodality imaging in the post-procedural setting is essential for early and accurate diagnosis to limit morbidity and mortality. We review common and uncommon treatment-induced pathologies affecting the genitourinary system via a case-based approach. We illustrate notable complications affecting the kidneys, ureters, bladder, and urethra induced by percutaneous procedures, external beam radiation, immunotherapy, laparoscopic/robotic pelvic surgery, and intravesicular BCG. Finally, we provide guidance on optimal imaging techniques for diagnosis and highlight the role of image-guided interventions for mitigation of complications.

Neoadjuvant chemotherapy for high-grade serous ovarian cancer: radiologic-pathologic correlation of response assessment and predictors of progression.

PURPOSE: Neoadjuvant chemotherapy is often administered for high-grade serous ovarian carcinoma (HGSC) prior to cytoreductive surgery. We evaluated treatment response by CT (simplified peritoneal carcinomatosis index [S-PCI]), pathology (chemotherapy response score [CRS]), laboratory markers (serum CA-125), and surgical outcomes, to identify predictors of disease-free survival. METHODS: For this retrospective, HIPAA-compliant, IRB-approved study, we identified 396 women with HGSC receiving neoadjuvant chemotherapy between 2010 and 2019. Two hundred and ninety-nine patients were excluded (surgery not performed; imaging/pathology unavailable). Pre- and post-treatment abdominopelvic CTs were assigned CT S-PCI scores 0-24 (higher score indicating more tumor). Specimens were assigned CRS of 1-3 (minimal to complete response). Clinical data were obtained via chart review. Univariate, multivariate, and survival analyses were performed. RESULTS: Ninety-seven women were studied, with mean age of 65 years ± 10. Interreader agreement was good to excellent for CT S-PCI scores (ICC 0.64-0.77). Despite a significant decrease in CT S-PCI scores after treatment (p < 0.001), mean decrease in CT S-PCI did not differ significantly among CRS categories (p = 0.20) or between patients who were optimally versus suboptimally debulked (p = 0.29). In a survival analysis, lower CRS (more viable tumor) was associated with shorter time to progression (p < 0.001). A joint Cox proportional-hazard models showed that only residual pathologic disease (CRS 1/2) (HR 4.19; p < 0.001) and change in CA-125 (HR 1.79; p = 0.01) predicted progression. CONCLUSION: HGSC response to neoadjuvant therapy by CT S-PCI did not predict pathologic CRS score, optimal debulking, or progression, revealing discordance between imaging, pathologic, biochemical, and surgical assessments of tumor response.

Pancreatic Transplantation: Surgical Anatomy and Complications.

Pancreatic transplantation is a complex surgical procedure performed for patients with chronic severe diabetes, often performed in combination with renal transplantation. Vascular and exocrine drainage anatomy varies depending on the surgical technique. Radiology plays a critical role in the diagnosis of postoperative complications, requiring an understanding of grayscale/Doppler ultrasound as well as computed tomography and MR imaging. In this review, we detail usual surgical methods and normal postoperative imaging appearances. We then review the most common complications following pancreatic transplants, emphasizing diagnostic features of vascular (arterial/venous), surgical, and diffuse parenchymal pathologic conditions on multiple imaging modalities.

Single-Time-Point Imaging for Dosimetry After [177Lu]Lu-DOTATATE: Accuracy of Existing Methods and Novel Data-Driven Models for Reducing Sensitivity to Time-Point Selection.

Estimation of the time-integrated activity (TIA) for dosimetry from imaging at a single time point (STP) facilitates the clinical translation of dosimetry-guided radiopharmaceutical therapy. However, the accuracy of the STP methods for TIA estimation varies on the basis of time-point selection. We constructed patient data-driven regression models to reduce the sensitivity to time-point selection and to compare these new models with commonly used STP methods. Methods: SPECT/CT performed at time period (TP) 1 (3-5 h), TP2 (days 1-2), TP3 (days 3-5), and TP4 (days 6-8) after cycle 1 of [177Lu]Lu-DOTATATE therapy involved 27 patients with 100 segmented tumors and 54 kidneys. Influenced by the previous physics-based STP models of Madsen et al. and Hänscheid et al., we constructed an STP prediction expression, TIA = A(t) × g(t), in a SPECT data-driven way (model 1), in which A(t) is the observed activity at imaging time t, and the curve, g(t), is estimated with a nonparametric generalized additive model by minimizing the normalized mean square error relative to the TIA derived from 4-time-point SPECT (reference TIA). Furthermore, we fit a generalized additive model that incorporates baseline biomarkers as auxiliary data in addition to the single activity measurement (model 2). Leave-one-out cross validation was performed to evaluate STP models using mean absolute error (MAE) and mean square error between the predicted and reference TIA. Results: At days 3-5, all evaluated STP methods performed very well, with an MAE of less than 7% (between-patient SD of <10%) for both kidneys and tumors. At other TPs, the Madsen method and data-driven models 1 and 2 performed reasonably well (MAEs < 17% for kidneys and < 32% for tumors), whereas the error with the Hänscheid method was substantially higher. The proof of concept of adding baseline biomarkers to the prediction model was demonstrated and showed a moderate enhancement at TP1, especially for estimating kidney TIA (MAE ± SD from 15.6% ± 1.3% to 11.8% ± 1.0%). Evaluations on 500 virtual patients using clinically relevant time-activity simulations showed a similar performance. Conclusion: The performance of the Madsen method and proposed data-driven models is less sensitive to TP selection than is the Hänscheid method. At the earliest TP, which is the most practical, the model incorporating baseline biomarkers outperforms other methods that rely only on the single activity measurement.

Malignant Epithelial Tumors of the Ovary: Pathogenesis and Imaging.

Epithelial ovarian neoplasms (EON) constitute the majority of ovarian cancers. Among EON, high-grade serous carcinoma (HGSC) is the most common and most likely to present at an advanced stage. Radiologists should recognize the imaging features associated with HGSC, particularly at ultrasound and MR imaging. Computed tomography is used for staging and to direct care pathways. Peritoneal carcinomatosis is common and does not preclude surgical resection. Other less common malignant EON have varied appearances, but share a common correlation between the amount of vascularized solid tissue and the likelihood of malignancy.

Adnexal Mass Imaging: Contemporary Guidelines for Clinical Practice.

Several recent guidelines have been published to improve accuracy and consistency of adnexal mass imaging interpretation and to guide management. Guidance from the American College of Radiology (ACR) Appropriateness Criteria establishes preferred adnexal imaging modalities and follow-up. Moreover, the ACR Ovarian-Adnexal Reporting Data System establishes a comprehensive, unified set of evidence-based guidelines for classification of adnexal masses by both ultrasound and MR imaging, communicating risk of malignancy to further guide management.

Imaging of pregnant and lactating patients with suspected adrenal disorders.

A high level of clinical suspicion is essential in the diagnosis and management of a suspected adrenal mass during pregnancy and the peripartum period. Timely recognition is important in order to improve fetal and maternal outcomes. Imaging is often performed to confirm a suspected adrenal lesion; however, increasing usage of diagnostic imaging during pregnancy and lactation has also increased awareness, concerns and confusion regarding the safety risks regarding fetal and maternal exposure to radiation and imaging intravenous contrast agents. This may lead to anxiety and avoidance of imaging examinations which can delay diagnosis and appropriate treatment. This article briefly reviews evidence-based recommended imaging modalities during pregnancy and the lactation period for the assessment of a suspected adrenal mass while recognizing that no examination should be withheld when the exam is necessary to confirm an important clinical suspicion. The imaging characteristics of the more common adrenal pathologies that may affect pregnant women are also discussed.

Imaging of Metastatic Disease to the Ovary/Adnexa.

Ovarian metastases tend to arise in young women, either in patients with known cancer or as the first presentation of a previously occult extraovarian malignancy. Although imaging cannot always differentiate between secondary and primary ovarian neoplasms, and pathologic confirmation is generally required, it is important to recognize suggestive imaging features on pelvic MR imaging. Ovarian metastases are commonly described as bilateral, solid, heterogenous, and hypervascular. Features vary based on the tumor origin and histology. Knowledge of these features, plus the appropriate clinical context, can help guide radiologists to include metastases in their differential diagnosis for atypical adnexal masses.

Advanced imaging and theranostics in thyroid cancer.

PURPOSE OF REVIEW: Thyroid cancers are endocrine neoplasms with diverse gene expression and behavior, for which constantly evolving anatomic and functional imaging/theranostic agents have an essential role for diagnosis, staging, and treatment. RECENT FINDINGS: To achieve definitive diagnosis, neck ultrasound and associated risk stratification systems, notably Thyroid Imaging Reporting and Data System (TI-RADS), allow improved thyroid nodule characterization and management guidance. Radioactive iodine-131 (RAI) has long played a role in management of differentiated thyroid cancer (DTC), with recent literature emphasizing its effectiveness for intermediate-high risk cancers, exploring use of dosimetry for personalized medicine, and potential for retreatment with RAI following tumor redifferentiation. Iodine-124 positron emission tomography/computed tomography (PET/CT) has promising application for DTC staging and dosimetry. F18-fluorodeoxyglucose (FDG) PET/CT is used for staging of high risk DTC and identification of noniodine-avid disease recurrences, with metabolic uptake consistently portending poor prognosis. Poorly differentiated and anaplastic thyroid cancers are best assessed with anatomic imaging and F18-FDG PET/ CT, though recent studies show a potential theranostic role for Ga68/Lu177-prostate-specific membrane antigen. Medullary thyroid cancers are evaluated with ultrasound, CT, magnetic resonance imaging, and various positron-emitting radiotracers for PET imaging (F18-DOPA, F18-FDG, and recently Ga68-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE)); the latter may enable treatment with Lu177-DOTATATE. SUMMARY: Multidisciplinary collaboration is essential to streamline appropriate management, given the wide array of available imaging and new therapies for metabolic and genetically complex cancers.

Gastric neuroendocrine neoplasms: a primer for radiologists.

Gastric neuroendocrine neoplasms are uncommon tumors with variable differentiation and malignant potential. Three main subtypes are recognized: type 1, related to autoimmune atrophic gastritis; type 2, associated with Zollinger-Ellison and MEN1 syndrome; and type 3, sporadic. Although endoscopy alone is often sufficient for diagnosis and management of small, indolent, multifocal type 1 tumors, imaging is essential for evaluation of larger, high-grade, and type 2 and 3 neoplasms. Hypervascular intraluminal gastric masses are typically seen on CT/MRI, with associated perigastric lymphadenopathy and liver metastases in advanced cases. Somatostatin receptor nuclear imaging (such as Ga-68-DOTATATE PET/CT) may also be used for staging and assessing candidacy for peptide receptor radionuclide therapy. Radiotracer uptake is more likely in well-differentiated, lower-grade tumors, and less likely in poorly differentiated tumors, for which F-18-FDG-PET/CT may have additional value. Understanding disease pathophysiology and evolving histologic classifications is particularly useful for radiologists, as these influence tumor behavior, preferred imaging, therapy options, and patient prognosis.

Targeting Missed Care Opportunities Using Modern Communication Methods: A Quality Improvement Initiative to Improve Access to CT and MRI Appointments.

PURPOSE: To evaluate the impact of automated text and phone call reminder systems on CT (computed tomography) and MRI (magnetic resonance imaging) missed care opportunities. METHODS: This was an IRB (institutional review board) exempt prospective interventional quality improvement study. The proportion of missed care opportunities (appointment made, no imaging performed) related to scheduled CT and MRI examinations were evaluated over 2 months (Month 1: reminder phone calls by staff 48-96 hours prior and mailed letter 1-2 weeks prior; Month 2: no manual call or letter, automated text message 24 hours prior, automated phone call 72 hours prior, automated patient portal message 7 days prior). The proportion of missed care opportunities was calculated in aggregate and by modality. Process control p-charts were generated. An a priori power analysis was performed. Chi-squared tests were performed. p-value < 0.017 was considered significant after Bonferroni correction. RESULTS: Missed care opportunities occurred for 2.82% (292/10348; 95% CI: 2.51-3.16) of all CT and MRI appointments using traditional communication and 2.44% (262/10719; 95% CI: 2.16-2.75) using automated communication (p = 0.09). Automated messaging did not significantly change the proportion of missed care opportunities for CT (traditional: 2.62% [95% CI: 2.23-3.06] vs. automated: 2.06% [95% CI: 1.70-2.48], p = 0.05) or MRI (traditional: 3.1% [95% CI: 2.60-3.66] vs. automated: 2.83% [95% CI: 2.40-3.30], p = 0.43). Process control p-charts showed dominance of common cause variation. CONCLUSION: Automated messaging did not meaningfully change the overall proportion of missed care opportunities compared to traditional human-initiated phone calls. Automated communications may reduce cost and improve efficiency without adversely affecting access to care.

False lumen enhancement characteristics on computed tomography angiography predict risk of aneurysm formation in acute type B aortic dissection.

OBJECTIVES: Differential luminal enhancement [between true lumen (TL) and false lumen (FL)] results from differential flow patterns, most likely due to outflow restriction in the FL. We aimed to assess the impact of differential luminal enhancement at baseline computed tomography angiography on the risk of adverse events in patients with acute type B aortic dissection (TBAD). METHODS: Baseline computed tomography angiographies of patients with acute TBAD between 2007 and 2016 (n = 48) were analysed using three-dimensional software at multiple sites along the descending thoraco-abdominal aorta. At each location, we measured contrast density in TL and FL [Houndsfield unit (HU)], maximal diameter (cm) and circumferential FL extent (°). Outcome data were collected via retrospective chart review. Multivariable logistic regression models were employed to determine the independent risk of TL-FL differential luminal enhancement on aneurysm formation (maximal diameter ≥55 mm) and medical treatment failure. RESULTS: Patients were predominately male (75%) and 52.8±12.9 years at diagnosis. The mean follow-up was 5.9±2.6 years, and 42% (n = 20/48) patients were diagnosed with thoraco-abdominal aortic aneurysm. The baseline absolute difference between FL and TL contrast density measured at 2 cm distal to primary entry tear (TL-FLabs-Tear) was significantly higher among patients who developed aneurysm (26 HU, IQR: 15-53 vs 13 HU, IQR: 4-24, P = 0.001). Aneurysm development during follow-up was predicted by TL-FLabs-Tear (odds ratio 1.07, P = 0.012) and baseline maximal aortic diameter (odds ratio 1.90, P < 0.001). High (≥18 HU) differential luminal enhancement was associated with lower rates of aneurysm-free survival and higher rates of medical treatment failure. CONCLUSIONS: Differential luminal enhancement may be a novel predictor of aneurysm formation among patients with acute TBAD.

Contemporary Guidelines for Adnexal Mass Imaging: A 2020 Update.

Incidental adnexal masses are commonly encountered at ultrasound, computed tomography, and magnetic resonance imaging. Since many of these lesions are surgically resected and ultimately found to be benign, patients may be exposed to personal and economic costs related to unnecessary oophorectomy. Thus, accurate non-invasive risk stratification of adnexal masses is essential for optimal management and outcomes. Multiple consensus guidelines in radiology have been published to assist in characterization of these masses as benign, indeterminate, or likely malignant. In the last two years, several new and updated stratification systems for assessment of incidental adnexal masses have been published. The purpose of this article is to offer a concise review of four recent publications: ACR 2020 update on the management of incidental adnexal findings on CT and MRI, SRU 2019 consensus update on simple adnexal cysts, O-RADS ultrasound risk stratification system (2020), and O-RADS MRI risk stratification system (2020).

Rural-Urban Residence and Stage at Breast Cancer Diagnosis Among Postmenopausal Women: The Women's Health Initiative.

BACKGROUND: Although social exposures have complex and dynamic relationships and interactions, the existing literature on the impact of rural-urban residence on stage at breast cancer diagnosis does not examine heterogeneity of effect. We examined the joint effect of social support, social relationship strain, and rural-urban residence on stage at breast cancer diagnosis. METHODS: Using data from the Women's Health Initiative (WHI) (n = 161,808), we describe the distribution of social, behavioral, and clinical factors by rural-urban residence among postmenopausal women with incident breast cancer (n = 7,120). We used rural-urban commuting area (RUCA) codes to categorize baseline residential addresses as urban, large rural city/town, or small rural town, and the surveillance, epidemiology, and end results staging system to categorize breast cancer stage at diagnosis (dichotomized as early or late). We then used univariable and multivariable logistic regression to estimate odds ratios (ORs) and associated 95% confidence intervals (95% CI) for the relationship between rural-urban residence and stage at breast cancer diagnosis. We included separate interaction terms between rural-urban residence and social strain and social support to test for statistical interaction. RESULTS: Of the social, behavioral, and clinical factors we examined, only younger age at WHI enrollment screening was significantly associated with late stage at breast cancer diagnosis (p = 0.003). Contrary to our hypothesis, rural-urban residence was not significantly associated with stage at breast cancer diagnosis among postmenopausal women ([adjusted OR, 95% CI] for urban compared with small town: 1.08 [0.76-1.53]; large town compared with small town: 1.16 [0.74-1.84]; and urban compared with large town: 0.93 [0.68-1.26]).The associations did not vary by social support or social strain (p for interaction between RUCA and social strain and social support, respectively: 0.99 and 0.17). CONCLUSIONS: Future studies should examine other potential effect modifiers to identify novel factors predictive or protective for late stage at breast cancer diagnosis associated with rural-urban residence.

Needs Assessment Using a Structured Prioritization Schema: An Open Letter to PACS Vendors.

PURPOSE: The aim of this work was to prioritize in a quaternary academic environment necessary elements of a replacement PACS. METHODS: This quality improvement work was conducted at one academic medical center and was "not regulated" by the institutional review board. Three workgroups (10-15 members each) with unique resident, fellow, and attending radiologists; IT specialists; and departmental leaders convened in 2018 to prioritize elements for a PACS replacement project, including integrated IT tools. Each workgroup met two or three times and represented one of three missions (clinical, research, and education). Six elements assigned the highest priority were distilled from each workgroup. The resulting 18 elements were condensed into survey format and distributed to all department residents, fellows, and faculty members for 5-point Likert-type prioritization stratified by mission. Data were collected over 2 weeks. RESULTS: The survey response rate was 37% (71 of 192; 17 of 44 residents, 3 of 27 fellows, and 51 of 121 faculty members). Self-reported work effort was 63 ± 26% clinical, 14 ± 11% education, 15 ± 21% research, and 8 ± 14% administration. Aggregate priority ratings across all domains were highest for "stable system with predictable behavior" (mean, 4.51), "minimizes repetitive non-value-added work" (mean, 4.40), "interoperability" (mean, 4.12), and "near-instantaneous load times" (mean, 4.07). Clinical-specific ratings for these elements were even higher (means, 4.85-4.90). The lowest aggregate scores were mobile device compatibility (mean, 3.03), connectivity to nonaffiliated sites (mean, 3.01), and integrated instant messaging (mean, 2.87). CONCLUSIONS: The department prioritized a stable and interoperable system that minimized non-value-added work. In other words, participants wanted a functioning PACS. PACS vendors should prioritize a reliable experience over niche add-ons.

Racial differences in breast cancer survival in a large urban integrated health system.

BACKGROUND: African American (AA) women are known to have poorer breast cancer survival than whites, and the differences may be related to underlying disparities in their clinical presentation or access to care. This study evaluated the relationship between demographic, treatment, and socioeconomic factors and breast cancer survival among women in southeast Michigan. METHODS: The population included 2387 women (34% AA) with American Joint Committee on Cancer stage I to III breast cancer who were treated at the Henry Ford Health System (HFHS) from 1996 through 2005. Linked data sets from the HFHS, the Metropolitan Detroit Cancer Surveillance System, and the US Census Bureau were used to obtain demographic and clinical information. Comorbidities were classified with the modified Charlson comorbidity index (CCI). Economic deprivation was categorized with a census tract-based deprivation index (DI), which was stratified into 5 quintiles of increasing socioeconomic disadvantage. RESULTS: Compared with whites, AA women were significantly more likely to have larger, hormone receptor-negative tumors and more comorbidities and to reside in an economically deprived area. In an unadjusted analysis, AAs had a significantly higher risk of death (hazard ratio [HR], 1.36; 95% confidence interval [CI], 1.16-1.59); however, after adjustments for clinical (age, stage, hormone receptor, and CCI) and societal factors (DI), the effect of race was not significant (HR, 1.13 [95% CI, 0.96-1.34] , and HR, 0.97 [0.80-1.19] respectively). CONCLUSIONS: Racial differences in breast cancer survival can be explained by clinical and socioeconomic factors. Nonetheless, AA women with breast cancer remain disproportionately affected by unfavorable tumor characteristics and economic deprivation, which likely contribute to their increased overall mortality.