Improving staging of rectal cancer in the pelvis: the role of PET/MRI.

PURPOSE: The role of positron emission tomography/magnetic resonance (PET/MR) in evaluating the local extent of rectal cancer remains uncertain. This study aimed to investigate the possible role of PET/MR versus magnetic resonance (MR) in clinically staging rectal cancer. METHODS: This retrospective two-center cohort study of 62 patients with untreated rectal cancer investigated the possible role of baseline staging PET/MR versus stand-alone MR in determination of clinical stage. Two readers reviewed T and N stage, mesorectal fascia involvement, tumor length, distance from the anal verge, sphincter involvement, and extramural vascular invasion (EMVI). Sigmoidoscopy, digital rectal examination, and follow-up imaging, along with surgery when available, served as the reference standard. RESULTS: PET/MR outperformed MR in evaluating tumor size (42.5 ± 21.03 mm per the reference standard, 54 ± 20.45 mm by stand-alone MR, and 44 ± 20 mm by PET/MR, P = 0.004), and in identifying N status (correct by MR in 36/62 patients [58%] and by PET/MR in 49/62 cases [79%]; P = 0.02) and external sphincter infiltration (correct by MR in 6/10 and by PET/MR in 9/10; P = 0.003). No statistically significant differences were observed in relation to any other features. CONCLUSION: PET/MR provides a more precise assessment of the local extent of rectal cancers in evaluating cancer length, N status, and external sphincter involvement. PET/MR offers the opportunity to improve clinical decision-making, especially when evaluating low rectal tumors with possible external sphincter involvement.

Using overbooking to manage no-shows in an Italian healthcare center.

BACKGROUND: In almost all healthcare systems, no-shows (scheduled appointments missed without any notice from patients) have a negative impact on waiting lists, costs and resource utilization, impairing the quality and quantity of cares that could be provided, as well as the revenues from the corresponding activity. Overbooking is a tool healthcare providers can resort to reduce the impact of no-shows. METHODS: We develop an overbooking algorithm, and we assess its effectiveness using two methods: an analysis of the data coming from a practical implementation in an healthcare center; a simulation experiment to check the robustness and the potential of the strategy under different conditions. The data of the study, which includes personal and administrative information of patients, together with their scheduled and attended examinations, was taken from the electronic database of a big outpatient center. The attention was focused on the Magnetic Resonance (MR) ward because it uses expensive equipment, its services need long execution times, and the center has actually used it to implement an overbooking strategy aimed at reducing the impact of no-shows. We propose a statistical model for the patient's show/no-show behavior and we evaluate the ensuing overbooking procedure implemented in the MR ward. Finally, a simulation study investigates the effects of the overbooking strategy under different scenarios. RESULTS: The first contribution is a list of variables to identify the factors performing the best to predict no-shows. We classified the variables in three groups: "Patient's intrinsic factors", "Exogenous factors" and "Factors associated with the examination". The second contribution is a predictive model of no-shows, which is estimated on context-specific data using the variables just discussed. Such a model represents a fundamental ingredient of the overbooking strategy we propose to reduce the negative effects of no-shows. The third contribution is the assessment of that strategy by means of a simulation study under different scenarios in terms of number of resources and no-show rates. The same overbooking strategy was also implemented in practice (giving the opportunity to consider it as a quasi-experiment) to reduce the negative impact caused by non attendance in the MR ward. Both the quasi-experiment and the simulation study demonstrated that the strategy improved the center's productivity and reduced idle time of resources, although it increased slightly the patient's waiting time and the staff's overtime. This represents an evidence that overbooking can be suitable to improve the management of healthcare centers without adversely affecting their costs and the quality of cares offered. CONCLUSIONS: We shown that a well designed overbooking procedure can improve the management of medical centers, in terms of a significant increase of revenue, while keeping patient's waiting time and overtime under control. This was demonstrated by the results of a quasi-experiment (practical implementation of the strategy in the MR ward) and a simulation study (under different scenarios). Such positive results took advantage from a predictive model of no-show carefully designed around the medical center data.

CA15-3 is a useful serum tumor marker for diagnostic integration of hybrid positron emission tomography with integrated computed tomography during follow-up of breast cancer patients.

BACKGROUND: The aim of this study was to evaluate the value of CA15-3 for the diagnostic integration of molecular imaging findings performed with hybrid positron emission tomography and computed tomography (PETCT) technology. METHODS: We retrospectively selected 45 patients with a median age of 60 years (range 39-85 years) and a previous history of breast cancer (BC) who had already been treated with surgery and other treatments. Three measurements of CA15-3 were collected within 1 year before PETCT examination, at 6-9 months 3-6 months and 0-3 months before PETCT. The prolonged clinical outcome or imaging follow-up was used to define disease relapse. An increase in tumor marker value was compared with PETCT findings and disease relapse. Sensitivity and specificity for both tests were calculated with respect to clinical outcome. RESULTS: Disease relapse was detected in 16 out of 45 BC patients. CA15-3 and PETCT showed 75% sensitivity with a specificity percentage of 76% for CA15-3 and 79% for PETCT. Serum CA15-3 expression levels were significantly higher in BC patients with multiple metastatic sites with hepatic involvement. Analysis of serial CA15-3 serum levels showed an increase in CA15-3 3-6 months before PETCT could identify BC patients at risk for relapse (AUC = 0.81). Moreover, patients receiving anti-hormonal or chemotherapy medications with negative PETCT and positive CA15-3 relapsed after a median time of 158 days compared to patients who were negative for both tests and who were free from disease for at least 1 year. CONCLUSIONS: Our results showed that serial increases in CA15-3 can be used to predict positive PETCT results in BC patients during follow-up. Increased levels of CA15-3 may be considered an early warning sign in patients needing accurate molecular imaging investigations, as they are at higher risk of recurrence. In cases of elevated levels, multiple lesions or liver involvement may exist. Also, patients receiving chemotherapeutic or anti-hormonal treatment who have negative PETCT scans and increased CA15-3 serum levels should be considered at risk for relapse, because the CA15-3-linked biochemical signal of the presence of a tumor can predict positive metabolic imaging.

Evaluation of the Diagnostic Performance of Positron Emission Tomography/Magnetic Resonance for the Diagnosis of Liver Metastases.

OBJECTIVE: The aim of this study was to compare the performance of positron emission tomography (PET)/magnetic resonance (MR) versus stand-alone PET and stand-alone magnetic resonance imaging (MRI) in the detection and characterization of suspected liver metastases. MATERIALS AND METHODS: This multi-institutional retrospective performance study was approved by the institutional review boards and was Health Insurance Portability and Accountability Act compliant, with waiver of informed consent. Seventy-nine patients with confirmed solid extrahepatic malignancies who underwent upper abdominal PET/MR between February 2017 and June 2018 were included. Where focal hepatic lesions were identified, the likelihood of a diagnosis of a liver metastasis was defined on an ordinal scale for MRI, PET, and PET/MRI by 3 readers: 1 nuclear medicine physician and 2 radiologists. The number of lesions per patient, lesion size, and involved hepatic segments were recorded. Proof of metastases was based on histopathologic correlation or clinical/imaging follow-up. Diagnostic performance was assessed using sensitivity, specificity, positive and negative predictive values, and receiver operator characteristic curve analysis. RESULTS: A total of 79 patients (53 years, interquartile range, 50-68; 43 men) were included. PET/MR had a sensitivity of 95%, specificity of 97%, positive predictive value of 97%, and negative predictive value of 95%. The sensitivity, specificity, positive predictive value, and negative predictive value of MRI were 88%, 98%, 98%, and 90% and for PET were 83%, 97%, 97%, and 86%, respectively. The areas under the curve for PET/MRI, MRI, and PET were 95%, 92%, and 92%, respectively. CONCLUSIONS: Contrast-enhanced PET/MR has a higher sensitivity and negative predictive value than either PET or MRI alone in the setting of suspected liver metastases. Fewer lesions were characterized as indeterminate by PET/MR in comparison with PET and MRI. This superior performance could potentially impact treatment and management decisions for patients with suspected liver metastases.

High Prevalence of Spinal Magnetic Resonance Imaging Findings in Asymptomatic Young Adults (18-22 Yrs) Candidate to Air Force Flight.

STUDY DESIGN: Cross-sectional, retrospective, magnetic resonance (MR) imaging study, performed during cadets' selection procedures of the Italian Air Force Academy. OBJECTIVE: To assess the prevalence of spinal MR imaging findings in asymptomatic young adults (18-22 yrs) candidate to Air Force Flight. SUMMARY OF BACKGROUND DATA: Spinal MR imaging findings are frequently detected in asymptomatic subjects. Literature prevalence data come from studies that analyze different patient populations, in a wide age range and in different spinal tracts. Chronic degenerative disease of the vertebral column often occurs in pilots exposed to high flight acceleration forces, thus resulting crucial for Air Force Academy to exclude vertebral disease in cadets. METHODS: Three hundred fifty asymptomatic young adults underwent a 3T MR examination of the entire spine. A structured radiological report was set up to classify and calculate the prevalence of spinal MR imaging findings. RESULTS: Two hundred seventy of 350 subjects (77%) presented spinal MR findings, while 80 of 350 candidates (23%) had no detectable MR imaging findings. One hundred six of 350 (30%) candidates had at least one disc desiccation and 47 of 350 (13%) presented at least one disc narrowing. Disc bulging was found in 176 of 350 (49%) cadets. Sixty-two of 350 (18%) subjects showed disc protrusion while 28 of 350 (8%) had disc extrusion. Forty-five of 350 (13%) candidates presented low grade intervertebral spondylosis and of these 12 had also facet joints spondylosis. Asymptomatic vertebral fractures were observed in 2 of 350 (<1%) cadets. CONCLUSION: A high rate of MR spinal imaging findings, similar to that of the adult population, was detected in our population of young asymptomatic subjects. Our results suggest that the process of aging spine, which is supposed to begin in the second decade of life, is morphologically appreciable in the immediate postadolescent period and this issue is of crucial importance when selecting military pilots. LEVEL OF EVIDENCE: 4.

Circulating miRNAs in Untreated Breast Cancer: An Exploratory Multimodality Morpho-Functional Study.

The aim of this study was to identify new disease-related circulating miRNAs with high diagnostic accuracy for breast cancer (BC) and to correlate their deregulation with the morpho-functional characteristics of the tumour, as assessed in vivo by positron emission tomography/magnetic resonance (PET/MR) imaging. A total of 77 untreated female BC patients underwent same-day PET/MR and blood collection, and 78 healthy donors were recruited as negative controls. The expression profile of 84 human miRNAs was screened by using miRNA PCR arrays and validated by real-time PCR. The validated miRNAs were correlated with the quantitative imaging parameters extracted from the primary BC samples. Circulating miR-125b-5p and miR-143-3p were upregulated in BC plasma and able to discriminate BC patients from healthy subjects (miR-125-5p area under the receiver operating characteristic ROC curve (AUC) = 0.85 and miR-143-3p AUC = 0.80). Circulating CA15-3, a soluble form of the transmembrane glycoprotein Mucin 1 (MUC-1) that is upregulated in epithelial cancer cells of different origins, was combined with miR-125b-5p and improved the diagnostic accuracy from 70% (CA15-3 alone) to 89% (CA15-3 plus miR-125b-5p). MiR-143-3p showed a strong and significant correlation with the stage of the disease, apparent diffusion coefficient (ADCmean), reverse efflux volume transfer constant (Kepmean) and maximum standardized uptake value (SUVmax), and it might represent a biomarker of tumour aggressiveness. Similarly, miR-125b-5p was correlated with stage and grade 2 but inversely correlated with the forward volume transfer constant (Ktransmean) and proliferation index (Ki67), suggesting a potential role as a biomarker of a relatively more favourable prognosis. In situ hybridization (ISH) experiments revealed that miR-143-3p was expressed in endothelial tumour cells, miR-125-5p in cancer-associated fibroblasts, and neither in epithelial tumour cells. Our results suggested that miR-125-5p and miR-143-3p are potential biomarkers for the risk stratification of BC, and Kaplan-Maier plots confirmed this hypothesis. In addition, the combined use of miR-125-b-5p and CA15-3 enhanced the diagnostic accuracy up to 89%. This is the first study that correlates circulating miRNAs with in vivo quantified tumour biology through PET/MR biomarkers. This integration elucidates the link between the plasmatic increase in these two potential circulating biomarkers and the biology of untreated BC. In conclusion, while miR-143-3b and miR-125b-5p provide valuable information for prognosis, a combination of miR-125b-5p with the tumour marker CA15-3 improves sensitivity for BC detection, which warrants consideration by further validation studies.

Image Quality and Dose Reduction by Dual Source Computed Tomography Coronary Angiography: Protocol Comparison.

PURPOSE: To compare image quality and radiation dose among different protocols in patients who underwent a 128-slice dual source computed tomography coronary angiography (DSCT-CTCA). METHODS: Ninety patients were retrospectively grouped according to heart rate (HR): 26 patients (group A) with stable HR ≤60 bpm were acquired using high pitch spiral mode (FLASH); 48 patients (group B) with irregular HR ≤60 bpm or stable HR between 60 and 70 bpm using step and shoot mode; and 16 patients (group C) with irregular HR >60 bpm or stable HR ≥70 bpm by retrospective electrocardiogram pulsing acquisition. Signal to noise ratio (SNR) and contrast to noise ratio (CNR) were measured for the main vascular structures. Moreover, the dose-length product and the effective dose were assessed. RESULTS: Both SNR and CNR were higher in group A compared to group C (18.27 ± 0.32 vs 11.22 ± 0.50 and 16.75 ± 0.32 vs 10.17 ± 0.50; P = .001). The effective dose was lower in groups A and B (2.09 ± 1.27 mSv and 4.60 ± 2.78 mSv, respectively) compared to group C (9.61 ± 5.95 mSv) P < .0001. CONCLUSION: The correct selection of a low-dose, HR-matched CTCA scan protocol with a DSCT scanner provides substantial reduction of radiation exposure and better SNR and CNR.