CT-derived radiomic features to discriminate histologic characteristics of pancreatic neuroendocrine tumors.

PURPOSE: To assess the ability of radiomic features (RF) extracted from contrast-enhanced CT images (ceCT) and non-contrast-enhanced (non-ceCT) in discriminating histopathologic characteristics of pancreatic neuroendocrine tumors (panNET). METHODS: panNET contours were delineated on pre-surgical ceCT and non-ceCT. First- second- and higher-order RF (adjusted to eliminate redundancy) were extracted and correlated with histological panNET grade (G1 vs G2/G3), metastasis, lymph node invasion, microscopic vascular infiltration. Mann-Whitney with Bonferroni corrected p values assessed differences. Discriminative power of significant RF was calculated for each of the end-points. The performance of conventional-imaged-based-parameters was also compared to RF. RESULTS: Thirty-nine patients were included (mean age 55-years-old; 24 male). Mean diameters of the lesions were 24 × 27 mm. Sixty-nine RF were considered. Sphericity could discriminate high grade tumors (AUC = 0.79, p = 0.002). Tumor volume (AUC = 0.79, p = 0.003) and several non-ceCT and ceCT RF were able to identify microscopic vascular infiltration: voxel-alignment, neighborhood intensity-difference and intensity-size-zone families (AUC ≥ 0.75, p < 0.001); voxel-alignment, intensity-size-zone and co-occurrence families (AUC ≥ 0.78, p ≤ 0.002), respectively). Non-ceCT neighborhood-intensity-difference (AUC = 0.75, p = 0.009) and ceCT intensity-size-zone (AUC = 0.73, p = 0.014) identified lymph nodal invasion; several non-ceCT and ceCT voxel-alignment family features were discriminative for metastasis (p < 0.01, AUC = 0.80-0.85). Conventional CT 'necrosis' could discriminate for microscopic vascular invasion (AUC = 0.76, p = 0.004) and 'arterial vascular invasion' for microscopic metastasis (AUC = 0.86, p = 0.001). No conventional-imaged-based-parameter was significantly associated with grade and lymph node invasion. CONCLUSIONS: Radiomic features can discriminate histopathology of panNET, suggesting a role of radiomics as a non-invasive tool for tumor characterization. TRIAL REGISTRATION NUMBER: NCT03967951, 30/05/2019.

An innovative 3D-3D superimposition for assessing anatomical uniqueness of frontal sinuses through segmentation on CT scans.

Anatomical uniqueness plays a significant role in the personal identification process of unknown deceased. Frontal sinuses have been widely used in the past decades for this purpose, mostly using 2D X-ray techniques. However, the modern 3D CT-based segmentation methods may help in developing novel and more reliable methods of identification. This study aims at assessing the anatomical uniqueness of frontal sinuses through the 3D model registration. Thirty subjects who underwent two maxillofacial CT scans (interval: 1 month to 5 years) were selected from a hospital database. Frontal sinuses were automatically segmented through ITK-SNAP open source software and the 3D models belonging to the same patient were automatically superimposed according to the least point-to-point difference between the two surfaces. Two hundred patients were randomly selected from the same database and undergo the same procedure to perform 200 superimpositions of frontal sinuses belonging to different individuals, equally divided between males and females (mismatches). Statistically significant differences of average root mean square (RMS) point-to-point distance between the group of matches and mismatches, as well as possible differences according to sex, were assessed through Mann-Whitney U test (p < 0.05). In the group of matches, RMS ranged between 0.07 and 0.96 mm (mean RMS 0.35 ± 0.23 mm), while in the group of mismatches, it ranged between 0.96 and 10.29 mm (mean RMS 2.59 ± 1.79 mm), with a statistically significant difference (p < 0.0001). Neither the matches nor the mismatches group showed statistically significant differences according to sex. This study proposes a novel 3D approach for the assessment of anatomical uniqueness of frontal sinuses, providing both morphological and quantitative analysis, and a new method of identification based on 3D assessment of frontal sinuses, applicable when ante-mortem CT scans are available.

Anatomy of the pterygopalatine fossa: an innovative metrical assessment based on 3D segmentation on head CT-scan.

PURPOSE: The pterygopalatine fossa is an important anatomical structure for several surgical and anaesthesiologic procedures; yet, very few data are available about its size. This study aims at providing a metrical assessment of pterygopalatine fossa through an innovative 3D segmentation procedure on head CT-scans. METHODS: CT-scans from 100 patients (50 males and 50 females) aged between 18 and 85 years were chosen for the study. Right and left pterygopalatine fossae were segmented through ITK-SNAP open source software. Height and volume were calculated on the acquired 3D models. In addition, anterior-posterior nasal spine distance, upper facial height (nasion-prosthion) and biorbital breadth (ectoconchion-ectoconchion) were measured as well. Statistically significant differences of height and volume according to sex and side were assessed through two-way ANOVA test: sexually dimorphic measurements were further assessed through one-way ANCOVA test using the three cranial measurements as covariates (p < 0.05). RESULTS: On average pterygopalatine fossa height was 24.1 ± 3.5 mm in males, and 22.8 ± 3.4 mm in females, whereas volume was 0.930 ± 0.181 cm3 in males and 0.817 ± 0.157 cm3 in females, with statistically significant differences according to sex (p < 0.05), but not to side (p > 0.05); interaction was negligible for both the measurements. ANCOVA test verified that sexual dimorphism of both measurements is independent from general cranial size (p < 0.05). CONCLUSIONS: The present study highlighted the sexual dimorphism of pterygopalatine fossa: results may improve the knowledge of this anatomical structure difficult to explore, but crucial in several fields of clinics and surgery.

Biomarkers from in vivo molecular imaging of breast cancer: pretreatment 18F-FDG PET predicts patient prognosis, and pretreatment DWI-MR predicts response to neoadjuvant chemotherapy.

OBJECTIVE: Human cancers display intra-tumor phenotypic heterogeneity and recent research has focused on developing image processing methods extracting imaging descriptors to characterize this heterogeneity. This work assesses the role of pretreatment 18F-FDG PET and DWI-MR with respect to the prognosis and prediction of neoadjuvant chemotherapy (NAC) outcomes when image features are used to characterize primitive lesions from breast cancer (BC). MATERIALS AND METHODS: A retrospective protocol included 38 adult women with biopsy-proven BC. Patients underwent a pre-therapy 18F-FDG PET/CT whole-body study and a pre-therapy breast multi-parametric MR study. Patients were then referred for NAC treatment and then for surgical resection, with an evaluation of the therapy response. Segmentation methods were developed in order to identify functional volumes both on 18F-FDG PET images and ADC maps. Macroscopic and histogram features were extracted from the defined functional volumes. RESULTS: Our work demonstrates that macroscopic and histogram features from 18F-FDG PET are able to biologically characterize primitive BC, and define the prognosis. In addition, histogram features from ADC maps are able to predict the response to NAC. CONCLUSION: Our work suggests that pre-treatment 18F-FDG PET and pre-treatment DWI-MR provide useful complementary information for biological characterization and NAC response prediction in BC.

Tailored breast cancer screening program with microdose mammography, US, and MR Imaging: short-term results of a pilot study in 40-49-year-old women.

PURPOSE: To evaluate the feasibility, performance, and cost of a breast cancer screening program aimed at 40-49-year-old women and tailored to their risk profile with supplemental ultrasonography (US) and magnetic resonance (MR) imaging. MATERIALS AND METHODS: The institutional review board approved this study, and informed written consent was obtained. A total of 3017 40-49-year-old women were invited to participate. The screening program was tailored to lifetime risk (Gail test) and mammographic density (according to Breast Imaging Reporting and Data Systems [BI-RADS] criteria) with supplemental US or MR imaging and bilateral two-view microdose mammography. The indicators suggested by European guidelines, US incremental cancer detection rate (CDR), and estimated costs were evaluated. RESULTS: A total of 1666 women (67.5% participation rate) were recruited. The average lifetime risk of breast cancer was 11.6%, and nine women had a high risk of breast cancer; 917 women (55.0%) had a high density score (BI-RADS density category 3 or 4). The average glandular dose for screening examinations was 1.49 mGy. Screening US was performed in 835 study participants (50.1%), mostly due to high breast density (800 of 1666 women [48.0%]). Screening MR imaging was performed in nine women (0.5%) at high risk for breast cancer. Breast cancer was diagnosed in 14 women (8.4 cases per 1000 women). Twelve diagnoses were made with microdose mammography, and two were made with supplemental US in dense breasts (2.4 cases per 1000 women). All patients were submitted for surgery, and 10 underwent breast-conserving surgery. The sentinel lymph node was evaluated in 11 patients, resulting in negative findings in six. Pathologic analysis resulted in the diagnosis of four ductal carcinomas in situ and 10 invasive carcinomas (five at stage I). CONCLUSION: A tailored breast cancer screening program in 40-49-year-old women yielded a greater-than-expected number of cancers, most of which were low-stage disease.