CT-based deep learning model for the prediction of DNA mismatch repair deficient colorectal cancer: a diagnostic study.

BACKGROUND: Stratification of DNA mismatch repair (MMR) status in patients with colorectal cancer (CRC) enables individual clinical treatment decision making. The present study aimed to develop and validate a deep learning (DL) model based on the pre-treatment CT images for predicting MMR status in CRC. METHODS: 1812 eligible participants (training cohort: n = 1124; internal validation cohort: n = 482; external validation cohort: n = 206) with CRC were enrolled from two institutions. All pretherapeutic CT images from three dimensions were trained by the ResNet101, then integrated by Gaussian process regression (GPR) to develop a full-automatic DL model for MMR status prediction. The predictive performance of the DL model was evaluated using the area under the receiver operating characteristic curve (AUC) and then tested in the internal and external validation cohorts. Additionally, the participants from institution 1 were sub-grouped by various clinical factors for subgroup analysis, then the predictive performance of the DL model for identifying MMR status between participants in different groups were compared. RESULTS: The full-automatic DL model was established in the training cohort to stratify the MMR status, which presented promising discriminative ability with the AUCs of 0.986 (95% CI 0.971-1.000) in the internal validation cohort and 0.915 (95% CI 0.870-0.960) in the external validation cohort. In addition, the subgroup analysis based on the thickness of CT images, clinical T and N stages, gender, the longest diameter, and the location of tumors revealed that the DL model showed similar satisfying prediction performance. CONCLUSIONS: The DL model may potentially serve as a noninvasive tool to facilitate the pre-treatment individualized prediction of MMR status in patients with CRC, which could promote the personalized clinical-making decision.

Radiologic and Clinicopathologic Findings of Inflammatory Myofibroblastic Tumor.

PURPOSE: The aim of the study was to describe the clinical, radiographic, and pathologic features of inflammatory myofibroblastic tumor (IMT) to enhance the recognition of this rare disease. MATERIALS AND METHODS: The clinical, imaging, and pathologic findings were retrospectively reviewed in 54 patients with IMT lesions, which were conformed by biopsy or surgical pathology. Of 54 patients, 51 had preoperative computed tomography (CT) examination and 13 had preoperative magnetic resonance imaging records. RESULTS: The clinical appearances of these 54 patients had some relationship with the locations of lesions. Of 54 IMT patients, 87.0% cases (47/54) had solitary lesion. The mean long diameter of the lesions located at the sites of chest, abdomen, and pelvic regions was bigger than that of other locations (F = 3.025, P = 0.038). On plain CT images, soft tissue mass was found in all IMT lesions, except for 3 lesions that arose in the intestine tract, appearing as focal or diffuse thickening in the bowel wall. After contrast administration, all lesions were persistently enhanced; 72.7% cases (24/33) demonstrated heterogeneous enhancement with various cystic regions. Comparing the CT features with different anatomic lesions, ill-defined margin on the plain CT images and calcification were seen more frequently in the lesions of the head and neck (P = 0.010 and 0.035); however, the other radiological findings had no significant differences (all P > 0.05). Twelve of 51 IMT patients showed invasion into adjacent structures. On magnetic resonance imaging, 92.3% lesions (12/13) showed soft tissue masses demonstrating isointense to hypointense contrast compared with skeletal muscle on T1-weighted images and heterogeneously high signals on T2-weighted images; 85.7%(6/7) of lesions were heterogeneously enhanced with cystic changes. Immunohistochemistry showed that the percentage of positive staining for SMA, vimentin, anaplastic lymphoma kinase, CD68, CD34, CD99, B-cell lymphoma/leukemia-2, cytokeratin, Desmin, and S-100 protein were 88.9%, 87.0%, 44.4%, 59.3%, 53.7%, 29.6%, 42.6%, 28.5%, 13.0%, and 24.1%, respectively. CONCLUSIONS: Inflammatory myofibroblastic tumor can involve any part of the body, and the clinical and radiological appearances are various owing to different anatomic sites. An ill-defined soft tissue mass heterogeneous enhancement with or without invasion into adjacent structures on computed tomographic or magnetic resonance images and positive staining for SMA and vimentin on immunohistochemical examination could suggest the diagnosis.

Texture analysis of apparent diffusion coefficient maps: can it identify nonresponse to neoadjuvant chemotherapy for additional radiation therapy in rectal cancer patients?

Background: Neoadjuvant chemotherapy (NCT) alone can achieve comparable treatment outcomes to chemoradiotherapy in locally advanced rectal cancer (LARC) patients. This study aimed to investigate the value of texture analysis (TA) in apparent diffusion coefficient (ADC) maps for identifying non-responders to NCT. Methods: This retrospective study included patients with LARC after NCT, and they were categorized into nonresponse group (pTRG 3) and response group (pTRG 0-2) based on pathological tumor regression grade (pTRG). Predictive texture features were extracted from pre- and post-treatment ADC maps to construct a TA model using RandomForest. The ADC model was developed by manually measuring pre- and post-treatment ADC values and calculating their changes. Simultaneously, subjective evaluations based on magnetic resonance imaging assessment of TRG were performed by two experienced radiologists. Model performance was compared using the area under the curve (AUC) and DeLong test. Results: A total of 299 patients from two centers were divided into three cohorts: the primary cohort (center A; n = 194, with 36 non-responders and 158 responders), the internal validation cohort (center A; n = 49, with 9 non-responders) and external validation cohort (center B; n = 56, with 33 non-responders). The TA model was constructed by post_mean, mean_change, post_skewness, post_entropy, and entropy_change, which outperformed both the ADC model and subjective evaluations with an impressive AUC of 0.997 (95% confidence interval [CI], 0.975-1.000) in the primary cohort. Robust performances were observed in internal and external validation cohorts, with AUCs of 0.919 (95% CI, 0.805-0.978) and 0.938 (95% CI, 0.840-0.985), respectively. Conclusions: The TA model has the potential to serve as an imaging biomarker for identifying nonresponse to NCT in LARC patients, providing a valuable reference for these patients considering additional radiation therapy.

Selenide Heterostructure Nanosheets with Efficient Near-Infrared Photothermal Conversion for Therapy.

Photothermal therapy has been regarded as one of promising ways for tumor treatment. However, nanoagents with highly efficient thermal conversion and good bio-compatibility are still needed to be developed in biomedicine. In this work, we prepared two-dimensional heterostructures with bismuth selenide and tungsten selenide nanosheets as photothermal nanoagents. Near-infrared photothermal conversion of selenide heterostructure nanosheets can reach up to 40.75% under 808 nm excitation. It is known that selenium is a critical element to human health. More importantly, our experiments with mice show that the heterostructure nanosheets have low toxicity and high biocompatibility both in vitro and in vivo. The nanoagents based on heterostructures can effectively realize photothermal tumor ablation. It is suggested that the developed selenide nanosheets have great potential application in cancer therapy.

Cardiovascular Risk Stratification by Automatic Coronary Artery Calcium Scoring on Pretreatment Chest Computed Tomography in Diffuse Large B-Cell Lymphoma Receiving Anthracycline-Based Chemotherapy: A Multicenter Study.

BACKGROUND: Balancing the cardiovascular risk and benefit of anthracycline-based chemotherapy in patients with diffuse large B-cell lymphoma is an important clinical issue. We aimed to evaluate whether the pretreatment coronary artery calcium score (CACS) can stratify the risk of cancer therapy-related cardiac dysfunction (CTRCD) and major adverse cardiovascular events (MACEs) in patients with diffuse large B-cell lymphoma receiving anthracycline-based chemotherapy. METHODS: The patients with diffuse large B-cell lymphoma from 4 hospitals were retrospectively enrolled. The CACS was automatically calculated on nongated chest computed tomography before treatment using artificial intelligence-CACS software and divided into 3 categories (0, 1-100, and >100). The associations between the CACS and CTRCD and between the CACS and MACEs were assessed by logistic regression and Fine-Gray competing-risk regression model. Nelson-Aalen cumulative risk curve was performed to assess the cumulative incidence of MACEs. RESULTS: A total of 1468 patients (785 men and 683 women; 100% Asian) were enrolled, and 362 and 185 patients developed CTRCD and MACEs, respectively. Compared with a CACS of 0 (n=826), there was stepwise higher odds of CTRCD with a CACS between 1 and 100 (n=356; odds ratio, 2.587) and a CACS >100 (n=286; odds ratio, 5.239). The CACS was associated with MACEs (1-100 versus 0: subdistribution hazard ratio 3.726; >100 versus 0: subdistribution hazard ratio 7.858; all P<0.001). Competing risk-adjusted MACEs rates for patients with a CACS of 0, 1 to 100, and >100 were 1.21%, 8.43%, and 11.19%, respectively, at 3 years, and 3.27%, 16.01%, 31.12%, respectively, at 5 years. CONCLUSIONS: The automatic CACS derived from chest computed tomography before treatment was helpful to identify high-risk patients of CTRCD and MACE and guide clinicians to implement cardiovascular protection strategies in patients with diffuse large B-cell lymphoma who received anthracycline-based chemotherapy.

MRI-based radiomics to compare the survival benefit of induction chemotherapy plus concurrent chemoradiotherapy versus concurrent chemoradiotherapy plus adjuvant chemotherapy in locoregionally advanced nasopharyngeal carcinoma: A multicenter study.

BACKGROUND AND PURPOSE: It remains uncertain whether induction chemotherapy (IC) plus concurrent chemoradiotherapy (CCRT) or CCRT plus adjuvant chemotherapy (AC) is more effective in patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC). This study aimed to develop and validate a joint radiomic and clinical signature (RCS) for the prognostic stratification of LA-NPCs and to identify patients who might benefit more from IC + CCRT or CCRT + AC. MATERIALS AND METHODS: Overall, 893 LA-NPC patients who received IC + CCRT or CCRT + AC were enrolled from four hospitals. RCS based on pretreatment magnetic resonance images and clinical data was constructed for predicting 5-year progression-free survival (PFS). The predictive ability of the RCS and TNM staging system for 5-year PFS, locoregional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were compared by Harrell's concordance indices (C-indices). Patients were divided into high- and low-risk subgroups based on RCS scores. The survival benefit of IC + CCRT vs. CCRT + AC in different subgroups was compared by Kaplan-Meier survival curves. RESULTS: The RCS combining the radiomic signature, TNM stage and EBV DNA demonstrated significantly higher C-indices than TNM stage for predicting 5-year PFS, LRRFS, DMFS and OS in the training and validation cohorts. In the high-risk group (RCS score ≥ 0.25), CCRT + AC achieved significantly better PFS, LRRFS, DMFS and OS than IC + CCRT. In the low-risk group (RCS score < 0.25), IC + CCRT yielded significantly better outcomes than CCRT + AC. CONCLUSION: The RCS provides a noninvasive way to predict the outcomes of LA-NPC and helps identify patients who may benefit more from IC + CCRT vs. CCRT + AC.

Rectal cancer restaging using 3D CUBE vs. 2D T2-weighted technique after neoadjuvant therapy: a diagnostic study.

OBJECTIVE: This study aimed to compare the accuracy of rectal cancer restaging after neoadjuvant therapy with 3D CUBE sequence with 2D T2-weighted fast spin-echo (FSE) sequence. METHODS: This retrospective study comprised 72 patients with rectal cancer confirmed by colonoscopy and biopsy. After neoadjuvant therapy, all patients underwent pelvic magnetic resonance imaging (MRI) examination at 1.5T MRI sequences including a single coronal 3D CUBE T2-weighted FSE sequence with 1.4 mm thickness and a 2D T2-weighted FSE sequence in the sagittal, coronal and axial planes with 5 mm thickness. The total acquisition time of the two sequences was recorded. Results were compared with postsurgical pathology (gold standard). The diagnostic accuracy was evaluated; and receiver operating characteristic (ROC) curves and the area under the curves (AUC) were calculated. RESULTS: The T category staging accuracy of 3D T2WI and 2D T2WI was 81.9% and 72.2%, respectively, for reviewer 1 and 86.1% and 75.0% for reviewer 2. The AUC of 3D was higher than that of 2D (0.878 vs. 0.783 for reader 1 and 0.905 vs. 0.796 for reader 2; both P < 0.05) when judging whether the tumor broke through the muscle layer. There was no significant difference between 3D and 2D in judging whether lymph nodes were malignant (AUC 0.719 vs. 0.698 for reader 1 and 0.740 vs. 0.698 for reader 2; both P > 0.05). There were no significant differences in the visibility of the rectal wall layer, tumor lesion and the overall image quality (all P > 0.05). Compared with 2D sequences, the 3D sequence had shorter acquisition time and higher signal intensity ratio (both P < 0.05). CONCLUSION: 3D CUBE T2-weighted sequences offer better diagnostic accuracy in rectal cancer restaging after neoadjuvant therapy when compared with 2D T2-weighted FSE sequences; it has a shorter scanning time and more versatility of orientation reconstruction.

The findings of CT and MRI in patients with metanephric adenoma.

BACKGROUND: Metanephric adenoma (MA) is a benign renal tumor that is difficult to distinguish from a malignant tumor via traditional radiography. The diagnosis of MA is often dependent on postsurgical histopathological examination. In the present report, the imaging features of MA on computer tomography (CT) and magnetic resonance imaging (MRI) were retrospectively evaluated. METHODS: Eight MA patients, 17-67 years of age, were pathologically confirmed and recruited between April 2009 and November 2014. Four of the eight patients were female. All patients underwent CT scanning, and one patient underwent MRI scanning. Three patients underwent CTA of the renal arteries. All patients underwent resection surgery (radical nephrectomy in five and nephron-sparing surgery in three patients). RESULTS: The average tumor size was 44.0 ± 23.6 mm. The lesions in 87.5 % cases were located both in the renal cortex and medulla and exhibited exophytic growth. Plain CT showed that MA tumors were solid, and the average CT value was 37.9 ± 6.7 HU. Dynamic contrast-enhanced CT revealed that enhanced degrees of MA tumors in the renal cortex, renal parenchymal, and pelvic phase were all lower than that of normal renal parenchyma. A slight enhancement in the renal cortex phase and an even higher enhancement in the renal parenchymal phase were observed in seven of the cases. Progressive enhancement in the pelvic phase was found in five cases and a slight decreased enhancement in the pelvic phase in two cases. MRI revealed that MA tumor was isointense on T1WI and isointense on T2WI with some slightly hyperintense areas in the center. CTA of the renal arteries revealed the nutrient artery in one patient and no nutrient artery in two. Immunohistochemical experiments demonstrated that most tumor cells were positive for vimentin, CK, and EMA. CONCLUSIONS: MA is a rare benign renal neoplasm. Detailed knowledge of the CT and MRI characteristics of MA plays an important role in MA diagnosis and treatment.

[Application of adaptive iterative dose reduction technique in CT enterography in diagnosing Crohn disease].

OBJECTIVE: To evaluate the application of low-dose CT enterography with adaptive iterative dose reduction(AIDR) technique in diagnosing Crohn's disease. METHODS: Retrospective analysis was performed on 26 patients diagnosed as Crohn's disease by the multidisciplinary team in our hospital. Low-dose CT enterography with 640-slice MDCT was performed on these 26 patients using adaptive iterative dose reduction(AIDR) technique. Characteristics of Crohn's disease in CT enterography images were independently analyzed by two radiologists who were experienced in Crohn's disease with calculating the total radiation dosage. RESULTS: The radiation dosage of 26 patients ranged from 5.58 to 12.90 [mean (9.00±2.00)] mSv, which was lower than conventional scan (around 15 mSv) known from the literatures. According to the images of CT enterography of 26 cases, bowel wall thickening with abnormal enhancement and lymphadenectasis were found in 25 cases with total 109 segmental bowel wall thickening. Among 25 thickening cases, enterostenosis was found in 16 cases, stratification enhancement in 12 cases and comb sign in 14 cases. Besides, it was found that 8 cases with hyperdense fat on the mesenteric side, 7 cases with intestinal fistula, 6 cases with abdominal cavity abscess, and 3 cases with anal fistula. CONCLUSION: CT enterography of Crohn's disease with adaptive iterative dose reduction technique is an effective method to evaluate Crohn's disease without compromising image quality with reduced radiation dosage.

[Clinical value of MR diffusion weighted imaging in prediction of pathological complete response of rectal cancer after neoadjuvant therapy].

OBJECTIVE: To evaluate the application value of magnetic resonance diffusion-weighted imaging (DWI) combined with routine T2WI sequence in the determination of pathological complete response (pCR) after neoadjuvant therapy for rectal cancer. METHODS: Clinical data of 51 cases with locally advanced mid-low rectal cancer undergoing neoadjuvant therapy plus radical resection in the Rectal Cancer Center at The Sixth Affiliated Hospital of Sun Yat-sen University from June 2012 to April 2013 were analyzed retrospectively. Magnetic resonance DWI and T2WI sequences scanning were performed within 1 week before neoadjuvant therapy and within 1 week before operation. Routine single T2WI sequence and DWI combined with T2WI sequence were used separately to predict the residual tumor and to compare with postoperative pathological examination. The prediction values of two methods were compared. RESULTS: Of 51 patients, 12 cases had pathological complete response (pCR). Prediction of DWI combined T2WI sequence was correct in 8 cases of pCR, whose sensitivity and specificity were higher than those of routine single T2WI sequence (66.7%, 94.9% vs. 33.3%, 84.6%). Prediction value of DWI combined T2WI sequence for pCR was significantly higher as compared to routine single T2WI sequence (AUC, 0.808 vs. 0.590, P=0.001). CONCLUSION: Compared with the routine single T2WI sequence, DWI combined with T2WI sequence can improve the prediction accuracy of pathological complete response.