Imaging findings after a total reconstructed breast with autologous fat transfer: what the radiologist needs to know.

Autologous fat transfer (AFT) is an upcoming technique for total breast reconstruction. Consequently, radiological imaging of women with an AFT reconstructed breast will increase in the coming years, yet radiological experience and evidence after AFT is limited.The surgical procedure of AFT and follow-up with imaging modalities including mammography (MG), ultrasound (US), and MRI in patients with a total breast reconstruction with AFT are summarized to illustrate the radiological normal and suspicious findings for malignancy.Imaging after a total breast reconstruction with AFT appears to be based mostly on benign imaging findings with an overall low biopsy rate. As higher volumes are injected in this technique, the risk for the onset of fat necrosis increases. Imaging findings most often are related to fat necrosis after AFT. On MG, fat necrosis can mostly be seen as oil cysts. The occurrence of a breast seroma after total breast reconstruction with AFT is an unfavourable outcome and may require special treatment. Fat deposition in the pectoral muscle is a previously unknown, but benign entity. Although fat necrosis is a benign entity, it can mimic breast cancer (recurrence).In symptomatic women after total breast reconstruction with AFT, MG and US can be considered as first diagnostic modalities. Breast MRI can be used as a problem-solving tool during later stage. Future studies should investigate the most optimal follow-up strategy, including different imaging modalities, in patients treated with AFT for total breast reconstruction.

Magnetic resonance assessment of sinusoidal obstruction syndrome after neoadjuvant chemotherapy for colorectal liver metastases is not reproducible.

BACKGROUND: Sinusoidal obstruction syndrome (SOS) due to chemotherapy can cause severe hepatotoxicity, leading to impaired outcome in patients with colorectal cancer. A previous study introduced gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) to diagnose SOS. PURPOSE: To assess the reproducibility of Gd-EOB-MRI-based SOS diagnosis and its relationship with response to chemotherapy and long-term outcome. MATERIAL AND METHODS: Twenty-six Gd-EOB-MRI scans of patients undergoing chemotherapy for colorectal liver metastases (CRLM) were retrospectively analyzed. Three radiologists, blinded to clinical data, independently scored presence and severity of SOS on a 5-point scale (0, definitely not present to 4, definitely present). Patients with a score ≥3 were considered SOS+. Inter-observer agreement between readers was assessed with kappa statistics. Response (RECIST 1.1.), occurrence of new CRLM during follow-up (hepatic progression) and overall survival (OS) were compared between patients with and without SOS. RESULTS: The inter-observer agreement of SOS scores was poor, with quadratic kappas of 0.17-0.40. For the binary outcome of SOS+ (confidence level [CL] 3-4) vs. SOS- (CL 0-2) agreement was poor, with kappas of 0.03-0.37. Median follow-up was 24 months (range 4-44 months). Response and OS between patients with and without SOS did not differ significantly for any of the readers. CONCLUSION: Inter-observer agreement for the diagnosis of SOS on Gd-EOB-MRI is poor. No significant correlation with relevant outcomes was found for any of the readers. Therefore, MRI for SOS diagnosis might be less useful than previously reported. Other techniques should be explored to accurately diagnose SOS in absence of histological confirmation.

Machine learning-based analysis of CT radiomics model for prediction of colorectal metachronous liver metastases.

PURPOSE: Early identification of patients at risk of developing colorectal liver metastases can help personalizing treatment and improve oncological outcome. The aim of this study was to investigate in patients with colorectal cancer (CRC) whether a machine learning-based radiomics model can predict the occurrence of metachronous metastases. METHODS: In this multicentre study, the primary staging portal venous phase CT of 91 CRC patients were retrospectively analysed. Two groups were assessed: patients without liver metastases at primary staging, or during follow-up of ≥ 24 months (n = 67) and patients without liver metastases at primary staging but developed metachronous liver metastases < 24 months after primary staging (n = 24). After liver parenchyma segmentation, 1767 radiomics features were extracted for each patient. Three predictive models were constructed based on (1) radiomics features, (2) clinical features and (3) a combination of clinical and radiomics features. Stability of features across hospitals was assessed by the Kruskal-Wallis test and inter-correlated features were removed if their correlation coefficient was higher than 0.9. Bayesian-optimized random forest with wrapper feature selection was used for prediction models. RESULTS: The three predictive models that included radiomics features, clinical features and a combination of radiomics with clinical features resulted in an AUC in the validation cohort of 86% (95%CI 85-87%), 71% (95%CI 69-72%) and 86% (95% CI 85-87%), respectively. CONCLUSION: A machine learning-based radiomics analysis of routine clinical CT imaging at primary staging can provide valuable biomarkers to identify patients at high risk for developing colorectal liver metastases.

MRI-based response patterns during neoadjuvant chemotherapy can predict pathological (complete) response in patients with breast cancer.

BACKGROUND: The main purpose was to investigate the correlation between magnetic resonance imaging (MRI)-based response patterns halfway through neoadjuvant chemotherapy and immunotherapy (NAC) and pathological tumor response in patients with breast cancer. Secondary purposes were to compare the predictive value of MRI-based response patterns measured halfway through NAC and after NAC and to measure interobserver variability. METHODS: All consecutive patients treated with NAC for primary invasive breast cancer from 2012 to 2015 and who underwent breast MRI before, halfway through (and after) NAC were included. All breast tumors were reassessed on MRI by two experienced breast radiologists and classified into six patterns: type 0 (complete radiologic response); type 1 (concentric shrinkage); type 2 (crumbling); type 3 (diffuse enhancement); type 4 (stable disease); type 5 (progressive disease). Percentages of tumors showing pathological complete response (pCR), > 50% tumor reduction and > 50% tumor diameter reduction per MRI-based response pattern were calculated. Correlation between MRI-based response patterns and pathological tumor reduction was studied with Pearson's correlation coefficient, and interobserver agreement was tested with Cohen's Kappa. RESULTS: Patients (n = 76; mean age 53, range 29-72 years) with 80 tumors (4 bilateral) were included. There was significant correlation between these MRI-based response patterns halfway through NAC and tumor reduction on pathology assessment (reader 1 r = 0.33; p = 0.003 and reader 2 r = 0.45; p < 0.001). Type-0, type-1 or type-2 patterns halfway through NAC showed highest tumor reduction rates on pathology assessment, with > 50% tumor reduction in 90%, 78% and 65% of cases, respectively. In 83% of tumors with type 0 halfway through NAC, pathology assessment showed pCR. There was no significant correlation between MRI-based response patterns after NAC and tumor reduction rates on pathology assessment (reader 1 r = - 0.17; p = 0.145 and reader 2 r = - 0.17; p = 0.146). In 41% of tumors with type 0 after NAC, pathology assessment showed pCR. CONCLUSION: MRI-based response patterns halfway through NAC can predict pathologic response more accurately than MRI-based response patterns after NAC. Complete radiological response halfway NAC is associated with 83% pCR, while complete radiological response after NAC seems to be correct in only 41% of cases.

Organ Preservation in Rectal Cancer After Chemoradiation: Should We Extend the Observation Period in Patients with a Clinical Near-Complete Response?

BACKGROUND: To assess whether extending the observation period in patients with a near clinical complete response (near cCR) after chemoradiation (CRT) leads to an impaired oncological outcome. METHODS: Patients who had a clinical complete response (cCR) 8-10 weeks after CRT restaging with magnetic resonance imaging and endoscopy were offered a watch-and-wait strategy (W&W1), while patients with a near cCR were offered to undergo local excision or a second restaging 6-12 weeks later. Patients who achieved a cCR at the second restaging were also offered a watch-and-wait strategy (W&W2). RESULTS: Overall, 102 patients with a cCR at the first restaging immediately entered the W&W1, while the remaining 68 patients had a near cCR: 19 patients underwent transanal endoscopic microsurgery and 49 patients opted for a second restaging. Additionally, 44/49 (90%) patients showed a cCR at the second restaging and entered the W&W2. Patients in the W&W1 group had a 2-year local regrowth-free rate (LRFR) of 84% and 2-year overall survival (OS) of 99%, while patients in the W&W2 group had a 2-year LRFR of 73% and OS of 98% (p > 0.05). Multivariable Cox regression analyses showed that late inclusion was not a significant predictive factor for higher risk of LR or lower non-regrowth disease-free survival. CONCLUSIONS: Overall, 90% of patients with a near cCR 8-10 weeks after CRT will proceed to a cCR 6-12 weeks later; therefore, it seems logical to extend the observation period rather than to proceed to surgery. Although there is a non-significant increase in local regrowth rate in these patients, it does not seem to impact the oncological outcome.

Whole liver CT texture analysis to predict the development of colorectal liver metastases-A multicentre study.

OBJECTIVES: CT texture analysis has shown promise to differentiate colorectal cancer patients with/without hepatic metastases. AIM: To investigate whether whole-liver CT texture analysis can also predict the development of colorectal liver metastases. MATERIAL AND METHODS: Retrospective multicentre study (n=165). Three subgroups were assessed: patients [A] without metastases (n=57), [B] with synchronous metastases (n=54) and [C] who developed metastases within ≤24 months (n=54). Whole-liver texture analysis was performed on primary staging CT. Mean grey-level intensity, entropy and uniformity were derived with different filters (σ0.5-2.5). Univariable logistic regression (group A vs. B) identified potentially predictive parameters, which were tested in multivariable analyses to predict development of metastases (group A vs. C), including subgroup analyses for early (≤6 months), intermediate (7-12 months) and late (13-24 months) metastases. RESULTS: Univariable analysis identified uniformity (σ0.5), sex, tumour site, nodal stage and carcinoembryonic antigen as potential predictors. Uniformity remained a significant predictor in multivariable analysis to predict early metastases (OR 0.56). None of the parameters could predict intermediate/late metastases. CONCLUSIONS: Whole-liver CT-texture analysis has potential to predict patients at risk of developing early liver metastases ≤6 months, but is not robust enough to identify patients at risk of developing metastases at later stage.

Contrast-enhanced spectral mammography in patients referred from the breast cancer screening programme.

OBJECTIVES: Feasibility studies have shown that contrast-enhanced spectral mammography (CESM) increases diagnostic accuracy of mammography. We studied diagnostic accuracy of CESM in patients referred from the breast cancer screening programme, who have a lower disease prevalence than previously published papers on CESM. METHODS: During 6 months, all women referred to our hospital were eligible for CESM. Two radiologists blinded to the final diagnosis provided BI-RADS classifications for conventional mammography and CESM. Statistical significance of differences between mammography and CESM was calculated using McNemar's test. Receiver operating characteristic (ROC) curves were constructed for both imaging modalities. RESULTS: Of the 116 eligible women, 113 underwent CESM. CESM increased sensitivity to 100.0% (+3.1%), specificity to 87.7% (+45.7%), PPV to 76.2% (+36.5%) and NPV to 100.0% (+2.9%) as compared to mammography. Differences between conventional mammography and CESM were statistically significant (p < 0.0001). A similar trend was observed in the ROC curve. For conventional mammography, AUC was 0.779. With CESM, AUC increased to 0.976 (p < 0.0001). In addition, good agreement between tumour diameters measured using CESM, breast MRI and histopathology was observed. CONCLUSION: CESM increases diagnostic performance of conventional mammography, even in lower prevalence patient populations such as referrals from breast cancer screening. KEY POINTS: • CESM is feasible in the workflow of referrals from routine breast screening. • CESM is superior to mammography, even in low disease prevalence populations. • CESM has an extremely high negative predictive value for breast cancer. • CESM is comparable to MRI in assessment of breast cancer extent. • CESM is comparable to histopathology in assessment of breast cancer extent.

Measurement of coronary calcium scores by electron beam computed tomography or exercise testing as initial diagnostic tool in low-risk patients with suspected coronary artery disease.

We determined the efficiency of a screening protocol based on coronary calcium scores (CCS) compared with exercise testing in patients with suspected coronary artery disease (CAD), a normal ECG and troponin levels. Three-hundred-and-four patients were enrolled in a screening protocol including CCS by electron beam computed tomography (Agatston score), and exercise testing. Decision-making was based on CCS. When CCS>or=400, coronary angiography (CAG) was recommended. When CCS<10, patients were discharged. Exercise tests were graded as positive, negative or nondiagnostic. The combined endpoint was defined as coronary event or obstructive CAD at CAG. During 12+/-4 months, CCS>or=400, 10-399 and <10 were found in 42, 103 and 159 patients and the combined endpoint occurred in 24 (57%), 14 (14%) and 0 patients (0%), respectively. In 22 patients (7%), myocardial perfusion scintigraphy was performed instead of exercise testing due to the inability to perform an exercise test. A positive, nondiagnostic and negative exercise test result was found in 37, 76 and 191 patients, and the combined endpoint occurred in 11 (30%), 15 (20%) and 12 patients (6%), respectively. Receiver-operator characteristics analysis showed that the area under the curve of 0.89 (95% CI: 0.85-0.93) for CCS was superior to 0.69 (95% CI: 0.61-0.78) for exercise testing (P<0.0001). In conclusion, measurement of CCS is an appropriate initial screening test in a well-defined low-risk population with suspected CAD.